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Edit (22 Dec, 2012):
During 2011, I owned a Rigol DS1052E (hacked), Owon SDS7102, and Hantek DSO5062B (hacked) each for about a month. All of them were returned because I felt each one was deficient enough in some aspect of usability that I could not justify the $400-$600 price tag at that moment in time. To me, it seemed like too much money to spend on something that felt frustrating in some respect - and would be replaced within a couple of years. Then this year I bought a Rigol DS2072 - and I'm finally really happy with a DSO - it feels a much better investment for the future than the other's did - and a much more professional piece of equipment. If you can afford a few hundred dollars more - I would highly recommend you check out my impressions of the Rigol DS2000 series (https://www.eevblog.com/forum/reviews/first-impressions-and-review-of-the-rigol-ds2072-ds2000-series-dso/).
Meanwhile, here is my Owon review - please watch the entire thing for both pros and cons:
Owon SDS7102 Complete Review (https://www.youtube.com/watch?v=eqcEi6ru4ZM#)
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Great news you got it finally. Yup, we have that 'cooling off' period in Poland too - it is 10 days for all purchases made remotely. I believe it is EU regulation. Anyway, could you post some video on YT in hi-res how this baby works? Just to see its 'look and feel', no comments are necessary. Thanks for the first part, waiting for the next one. :)
Cheers,
Patryk
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Thank you!
Finally some news on one of the OWON SDS series scopes. I'm excited, and frightened to see what comes next. Too bad on the firmware.
Would love to see photos/vids of the function of the scope.
Bren
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cool, waiting for deeper review.
Btw, about the firmware things, as i got my first Tekway the firmware was really crap, then within one month i got
i believe 2 or 3 new versions before i was able to use that scope. So for sure, it can be that first models does have bugs
or sometimes really useless - on the other side, hmm, for Tekway it was first multilanguage-enabled scope, before
that they did only chinese menu (so maybe an excuse, but only maybe). Later they finally managed to made
nice working firmware (at that time i decided to post anything about them). Few months later Hantek shareholder
bought them and new developers team rewrote the firmware - so the story remains, crap on the beginning,
really useless features, tons of bugs. It tooks 6 months for them to fix all these issues, but finally they did.
So what i'm trying to say is, give Owon a chance (meaning while doing review). For your personal decision
about which is better, i would say write an email to Owon and tell them what you don't like.
If you got an answer like "yes we know" then you can be sure (or at least hope) that they will fix it,
if you get no answer, well then you know what to do.
Of course we all know this slogan "cheap, cheaper, china" - but it didn't means automatically that there
is no support and no continuous development on firmware only because it was "cheap".
For me, as i saw the "good will" from Tekway the decision was much easier, i've send back other scopes
and chosed Tekway.
Owon is producing DSOs since years, and to be very honest i never ever saw any firmware updates from them
- which didn't means of course they not having them. UNI-T for example is sending firmware updates
only via email, Tonghui too, Tekway actually the same (Hantek is publishing the fw on website)
Anyway, let's start the review :)
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Owon is producing DSOs since years, and to be very honest i never ever saw any firmware updates from them
Yes, this is what worries me... can any owner of any piece of Owon equipment confirm if they've ever received or downloaded a firmware update?
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Looking forward to the review too. Thanks for making this available. Hope you can post as many photos as you can.
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Really looking forward to your insight. please also point out the different in the UI between Owon and Rigol that you have , so we know why you don't like the Owon UI. :)
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Here's the first part - a look at the packaging, general design, and overall build quality of the unit:
Edit: See First post.
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nice review...
Probes - yeah, they from Texas, others (HanTekway, Tonghui, ???) using them too, then not that bad.
IR Hole/LED - remote control, IR transfer, remote trigger or light sensor for TFT dimming?
Whatever it is, could be interessting.
VGA/RS232 port - a big ???? However VGA port is already a big plus.
FAN - again plus
Buttons - big minus, construction and type of buttons, just ugly. I would probably replace them by softer buttons ...
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Great hardware review.
I am still thinking if I should get this or Atten ADS1102CML.....
Atten ADS1102CML seems to have a faster response (eg. response to a button pressed) firmware than this Owon.
On the other hand, this may be interesting to watch. At least to have a feel on the Owon SDS series. This video is a SDS6062 with another brand:
http://www.tmatlantic.com/e-store/index.php?SECTION_ID=262&ELEMENT_ID=6671 (http://www.tmatlantic.com/e-store/index.php?SECTION_ID=262&ELEMENT_ID=6671)
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nice review Mark.
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Great in depth review of the front and sides.
But, No Fine Control!? :-\.... That's disappointing. I noticed they didn't mention anything about that in the manual either, I was hoping they just... forgot to mention it.
To stop that slippage on a smooth desk you could probably wrap a piece of thin rubber around the scopes back foot.
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Great review, looking forward to seeing part 2.
Any thoughts on waveform update rate and frontend/adc noise level?
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Concur, you're a natural; clear diction good ergonomic insights. You should do more!
The ergonomics of the Owon look great; so slim and nicely laid out, but looking forward to its real performance, best not to judge a book by its cover.
Minor issues:
The Rigol 1052e probes, if they are RP 2200 are 200 MHz probes. While that seems like a lot for a 60 MHz scope, that's the sine wave rating; for looking at square waves you'll start to see roll offs at 9th harmonic, so in the 20MHz arena, and probably definitely at the 5th harmonic, > 40 MHz will likely be probe induced artifacts. Its partly a reason 200 MHz probes ship with 60 MHz scopes.
Great review, looking forward to seeing part 2.
Any thoughts on waveform update rate and frontend/adc noise level?
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Thanks everyone.. doing the best I can here considering my lack of knowledge and experience when dealing with DSOs. I hope to post a video part 2 of extensive use of the firmware - it's MANY problems - and it's few nice features - but first I'm plowing through reading material: Nyquist theorem applied to DSOs; ADC interleave distortion, and, well... most of you know the rest - and I'm also taking notes while running tests to save video recording and editing time later.
I could use suggestions in tests I could run or specs I might check with what I have on hand.... which is very little, I'm afraid. I've gotten by for years with a 30-year old 25MHz Tektronix analog scope, a 10 year-old Fluke DMM, and assorted logic probes, etc. So I don't have a faster scope, spectrum analyzer, etc. Just the Hantek AWG - and of course, I have tons of digital circuitry with which I could generate, at the very least, fast, repetitive clock signals.
But in the meanwhile, here are some screen captures and some of the info I've compiled. The first 6 .pngs are exact comparisons between the Rigol and Owon made using the same test setup with the DDS3X25 and the same settings on the scope (except you'll notice the volts/div is off - on the Rigol the inputs were set to 10x - on the Owon 1x - but the ratio between the channels is the same). I could not replicate the 75MHz result I had with the Rigol on the Owon. I'm not sure if this is due to the fact that 75MHz from the Hantek is not particularly stable - and I managed to get lucky with the Rigol - or, more likely, problems with the Owon. This was just an averaging issue (as pointed out by saturation) - which I used on the Rigol for the unstable 75MHz, but forgot to do on the Owon.
Although the 100MHz .pngs from the Owon don't look too bad, what is odd is that I have the display set to dots, not vectors, and the sine wave coming from the Hantek is exactly 2 points per period; i.e. a triangle wave. Why is the Owon showing a sine? Is it because I can't turn off sin(x) on the Owon scope? The 2 .pngs after the 100MHz screen caps show the saved 100MHz waveform brought into the Owon PC software - two times saved, one after the other - with different sample points on the waveform. Again, I'm not sure if this is due to the instability of the DDS3X25 at this high frequency, but it doesn't look good to me.
Other data, problems, or issues I've discovered:
No Equivalent Time Sampling available. That kind of sucks - I just assumed all modern DSOs had this - it's very handy for fast repetitive signals in digital circuits.
No way to turn off sin(x) - as mentioned above.
When using the frequency counter (on the trigger channel), the count becomes more and more incorrect the further the trigger level is moved below the zero line of the waveform. As mentioned in another post, I haven't replicated this bug since the first time, so it's intermittent - and not easily - because I couldn't repeat it. So, it's not that important - because you notice it right away when playing with trigger level (and it works fine always when trigger level >= 0).
It takes exactly 4 minutes to save the full 10Mpts to the USB hosted device (during which, of course, the scope is doing nothing else). That works out to a data rate of about 333kbps. I haven't checked the USB to PC transfer rates yet, but I will. It also takes exactly 35 seconds to save a screen image to the USB hosted device. It takes the PC software about one second to transfer a full 10Mpt record from the scope - a little better than the 4 minutes needed to write it to a USB stick, yes? ;) That's around 80Mbps, which = 6.5x > full bandwidth USB 1.1 - and about 5x < max. bandwidth 2.0. So it's definitely USB 2.0 as advertised. It's certainly a big improvement over communication speeds with either the Rigol or the Hantek AWG. To recap: the Owon appears to use USB 1.1 as host - USB 2.0 as device.
The 'Copy' button does NOT work to copy screen images to the hosted device - as the manual says it will. Obviously, you can still do it through the 'Save' menu, but this means you can't do screen captures with the different menus displayed. Now I AM getting the 'Copy' button to work as described in manual - so it's a slight bug (sometimes yes sometimes no). I haven't cracked it's logic yet :)
The screen is gorgeous - not doubt about it - and the VGA output works great and should be on every DSO - but the firmware's usage of screen real-estate in general is not good (which is so sad on an 800x600 display). They don't have split-screen modes for FFT, or, at the very least, for zooming in on waveforms.
The measure functions seem pretty weak to me. You can only have 4 measurements at a time on that massive screen (unless using Show All, which is problematic itself, as mentioned below) - and the procedure you go through to add or remove each one is bad interface design. Also, some of the measurement abbreviations they use are strange and not following standards.
Actually, you can have 8 measurements on the screen at one time: it looks like only 4 will fit in the given display space, but when you add a 5th, it pops the Channel and Sample settings out into a different part of the screen (unexpectedly). So, this is actually fine - 8 is plenty in most circumstances - and mitigates the problem with Show All mentioned below. Also, when I was adding measurements before (it uses a 3-tiered menu system), I assumed you had to press the encoder knob (which you turn to select which measurement you want) in order to confirm the selection - and I hate when you have to press encoder knobs to select anything (inevitably the selection often jumps to a different one by the act of pressing) - but this is not the case - so I've started to warm up a bit to the Owon's menu system.
The Show All is annoying, since it blocks much of the screen (see the attached .png) - and it doesn't actually update if you alter settings while it's displayed - it just shows the frozen measurements from when it was invoked. Not much use in real-time situations.
The firmware uses a two or three menu system (bottom menu, then side menu, then sometimes a floating menu on the other side), and although it's handy in a few cases, it's really - from my point of view - poor less-than-optimum software design. The Rigol also has some poor design in terms of the menus, but it's at least understandable because of the limits of screen real-estate and buttons. The Owon has 10 dedicated menu buttons - and a massive screen - so there's no excuse (except the obvious - saving money) for not having a well thought out menu system. The menu system has started to grow on me a bit - it's still far-from-perfect (but which DSO is?) - but it's perhaps equally advantageous to disadvantageous (50%/50%) - as opposed to my previous opinion (20%/80%). I have much more to say about it - but will save it for the final video review.
The Owon PC software became EXTREMELY slow then crashed (on my Intel i7 950 Quad-core) when trying to view an entire saved 10Mpt file of a 2.5MHz square waveform all at once (>1ms/div). It worked for a saved 10Mpt file of sampled noise - but not the square wave.
That's all for now.
Edit: Added 'Copy' button bug above.
Edit2: Changed my opinion of the measurement features above. They actually aren't too bad (although the Show All position on screen [and non-real time function] is still rather silly). Also, the menu system seems a little less bad than previously mentioned.
Edit3: Changed notes on frequency counter and 'Copy' button above.
Edit4: Added speed results for USB to PC transfer.
Edit5: Posted a summary of thoughts on Page 3. Video Part2 may or may not come later.
Edit6: Revised comments about 75MHz screen cap and USB speeds above.
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Big thanks for the review part 1. :)
UPDATE:
I've just read your last post and the firmware of this DSO doesn't look good at all. I only hope they still consider it as work-in-progress, and not the final version. I am also a little bit worried about hi-speed signals on Owon, but i'm not expert here. Usability was probably on the bottom of the list when they designed this product. What a shame. Btw, have you contacted Owon yet regarding all the issues?
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No Equivalent Time Sampling available. That kind of sucks - I just assumed all modern DSOs had this - it's very handy for fast repetitive signals in digital circuits.
right, but this makes only sense when the input stage/bw filter is really allowing to have a benefit. For example a cheap
60MHz Tonghui DSO (with -3db on 75MHz) when sampling with 400MSs can show perfectly 300MHz signals in equivalent
mode (of course with reduced amplitude) where on 200MHz Hantek sampling with 1GSs it does not matter what you enable - the waveform looks always (almost) the same - even if i remove bw filter (or set it to 900MHz) equ. sampling is not really
working as expected. So well, is it importnat? Depends, i can work with avg sampling too.
No way to turn off sin(x) - as mentioned above.
i personaly never used linear interpolation on the TDS754D, so i'm not missing it on the HanTekway.
But for sure, additional feature is always welcome.
When using the frequency counter (on the trigger channel), the count becomes more and more incorrect the further the trigger level is moved below the zero line of the waveform.
the freq. counter should in principle work up to plus/minus Vrms trigger level for sinus wave (at least ±354mV for 1Vpp) ,
if not then it's not good enough.
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I have tons of digital circuitry with which I could generate, at the very least, fast, repetitive clock signals.
Try to find a signal with a very fast rise / fall time (eg. 1ns), but preferably a fairly low repetition rate (eg. 1MHz). This gives you a very broad range of (odd) harmonics, and is a good measure for frequency response. Since you don't have a faster scope, you can't verify the actual shape, but you can compare the two scopes.
Although the 100MHz .pngs from the Owon don't look too bad, what is odd is that I have the display set to dots, not vectors, and the sine wave coming from the Hantek is exactly 2 points per period; i.e. a triangle wave. Why is the Owon showing a sine? Is it because I can't turn off sin(x) on the Owon scope? The 2 .pngs after the 100MHz screen caps show the saved 100MHz waveform brought into the Owon PC software - two times saved, one after the other - with different sample points on the waveform. Again, I'm not sure if this is due to the instability of the DDS3X25 at this high frequency, but it doesn't look good to me.
Seems like the signal is indeed under sampled. Is it sampling at 500MS/s? Does turning off one channel help? Note that a signal near its rated bandwidth is expected to look like a sine. The rated bandwidth is the -3dB point, and it will roll off with about -6dB/octave (sometimes even faster). That means that the fundamental will be about 30% down, and the harmonics even more. Attenuating the harmonics makes any signal look sinusoidal.
No Equivalent Time Sampling available. That kind of sucks - I just assumed all modern DSOs had this - it's very handy for fast repetitive signals in digital circuits.
Apart from clock, few digital signals are repetitive unless you can change the program or can trigger on bit patterns. ETS is often poorly implemented in cheap scopes IMO. To make use of the extra samples, the trigger stability needs to be very good. In a modern scope, real-time sampling rate is usually good enough for the analog bandwidth. Not much point in sampling a 100MHz sine at 10GS/s.
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right, but this makes only sense when the input stage/bw filter is really allowing to have a benefit. For example a cheap 60MHz Tonghui DSO (with -3db on 75MHz) when sampling with 400MSs can show perfectly 300MHz signals in equivalent mode (of course with reduced amplitude) where on 200MHz Hantek sampling with 1GSs it does not matter what you enable - the waveform looks always (almost) the same - even if i remove bw filter (or set it to 900MHz) equ. sampling is not really working as expected. So well, is it importnat? Depends, i can work with avg sampling too
Apart from clock, few digital signals are repetitive unless you can change the program or can trigger on bit patterns. ETS is often poorly implemented in cheap scopes IMO. To make use of the extra samples, the trigger stability needs to be very good. In a modern scope, real-time sampling rate is usually good enough for the analog bandwidth. Not much point in sampling a 100MHz sine at 10GS/s.
Well, working with µCs, it's easy to change firmware to generate repetitive signals for debugging - but you both make good points since I didn't realize ETS was poorly implemented on some (many?) of these cheaper scopes. I tested it on the Rigol with somewhat higher frequency signals and it seemed to work fairly well.
the freq. counter should in principle work up to plus/minus Vrms trigger level for sinus wave (at least ±354mV for 1Vpp) ,
if not then it's not good enough.
Strange, I haven't been able to replicate that freq.counter bug again - it definitely was happening when I was measuring 2 channels - I played with it for awhile wondering what the hell it was doing... but the last few times I've tried to repeat it - I can't. So it's certainly happening with some combination of settings - but not others.
Here are a few other .pngs - following a suggestion from tinhead (@tinhead - I could only check noise level at 5mv/div - at 2mv/div setting 20MHz filter is on automatically), plus some reading on interleave distortion. I think the file names are self-explanatory. Note that the single shot 0.1MHz, 1MHz, 10MHz, and 50MHz sine waves used by the FFTs are generated by the Hantek with 2000, 200, 20, and 4 points respectively.
BTW, from all I can tell, the Owon does sample at it's full speed (1GS/s single - 500MS/s double) when using the whole 10Mpts.
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Here are a few other .pngs - following a suggestion from tinhead (@tinhead - I could only check noise level at 5mv/div - at 2mv/div setting 20MHz filter is on automatically)
yeah "it's not a bug its'a feature", you have probably to disable it manually again.
I did patched away that's "feature" on HanTekway, if i wish to enable something then only if i wish.
Why some developers can't understand that something like autofilter need to be implemented
as user selectable option, that's 10 lines in code.
BTW, from all I can tell, the Owon does sample at it's full speed (1GS/s single - 500MS/s double) when using the whole 10Mpts.
so you did single shot, zoomed out and the visible record length is 10ms when in single chan mode
and 2 x 20ms when both chans enabled ? If so, then that's an overkill for many other DSOs.
EDIT: i forgot to mention something, Owon can do an CSV export, look on the header of that file (or count of data lines),
even if we think it is sampling with 1GSs and does have 10Mpoints it can be still 800MSs and 8Mpoints - both are resulting
in exact the same record length.
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FYI marmad on these issues:
I do get a reproducible 75 MHz out of the 3x25 with the factory software viewed on the Rigol. Its fairly similar to what you've posted. Here from an old post on the 3x25 thread:
(https://www.eevblog.com/forum/index.php?action=dlattach;topic=2170.0;attach=5349;image)
Curious on the Owon sine at 100 MHz. On the Rigol, now using mechatrommer's software, the reduced data points does show in the interpolation as a distorted sine, here's mechas screen grabs:
(https://www.eevblog.com/forum/index.php?action=dlattach;topic=2170.0;attach=6842;image)
I could not replicate the 75MHz result I had with the Rigol on the Owon. I'm not sure if this is due to the fact that 75MHz from the Hantek is not particularly stable - and I managed to get lucky with the Rigol - or, more likely, problems with the Owon.
Why is the Owon showing a sine? Is it because I can't turn off sin(x) on the Owon scope? The 2 .pngs after the 100MHz screen caps show the saved 100MHz waveform brought into the Owon PC software -
No Equivalent Time Sampling available. ...
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I do get a reproducible 75 MHz out of the 3x25 with the factory software viewed on the Rigol.
how do you produce that clean 75MHz signal out of 3x25? what factory software?
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so you did single shot, zoomed out and the visible record length is 10ms when in single chan mode and 2 x 20ms when both chans enabled ?
@tinhead - Yes, that's exactly what I did. But let me tell you, the 10Mpts of memory, just like the gorgeous display, is another example of nice hardware - which is not taken full advantage of by the software. When you are 'zoomed in' on a large record (small s/div), the encoder knob still moves you horizontally at the same speed through the record as always - it takes forever to move around it - and it's easy as pie to get lost. Why not, for example, if the scope is stopped and you're just browsing the data, have the encoder movement different and faster for zooming and jumping through the long record - as well as change the display feedback to better locate your position? Also, the Owon PC software is crap, so trying to look at these long records there is tedious - but that I could rewrite, so it's not such a problem.
If so, then that's an overkill for many other DSOs.
Sure, for most things, but if you need to log data over time, it can be a godsend.
Curious on the Owon sine at 100 MHz. On the Rigol, now using mechatrommer's software, the reduced data points does show in the interpolation as a distorted sine
@saturation - yes, the 3X25 only uses 2 points to represent a 100MHz sine wave so it's actually more like a perfect triangle wave. But since I can't switch off sin(x) on the Owon, there's no way for me to see the actual data points it is sampling (it always shows the interpolation) unless I save the waveform and take it somewhere else to look at it. I wish I had a high quality function generator to really test this scope with.
I tell you, this has to be the most frustrating thing I've purchased lately - leaving aside the unknown electronics for the moment - except for the stiff membrane switches and the slightly cheap-feeling smaller encoder knobs - the design, ergonomics, and hardware (at least on the outside) are attractive and very appealing. Who owns a cheap Chinese DSO but doesn't want a thinner desktop model, or an 8" 800x600 screen, or an optional 4 hour lithium battery, or a whisper quiet fan, or a smarter trigger pass output, or VGA output (it's great to see the waveforms really huge from a distance away when probing), or 10Mpts of memory? You can't use this Owon and not feel that this is the direction many of the Chinese DSO makers will be moving in the future. But the firmware is discouraging and there is so much untapped potential.
I have to decide tomorrow (or Friday morning at the latest) if I will keep the Owon or return it and go for the Hantek. It would be kind of a shame to relinquish the flash new hardware, but I can see by all I've read that the Hantek firmware is better (and the electronics are proven) - and even though I would end up with a DSO without as many initial bells and whistles, I'd have one which is less frustrating and probably more useful in the long term.
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Sorry mecha, its not without postprocessing, its using the original Hantek software with averaging. Here's are the full settings:
Analog Ch State Scale Position Coupling BW Limit Invert
CH1 On 50.0mV/ 16.0mV DC Off Off
Analog Ch Impedance Probe
CH1 1M Ohm 1X
Time Time Ref Main Scale Delay
Main Center 5.000ns/ 0.000000s
Trigger Source Slope Mode Coupling Level Holdoff
Edge CH1 Rising Auto DC -16.0mV 500ns
Acquisition Sampling Averages Memory Depth Sample Rate
Average Realtime 256 Normal 500.0MSa
Math Source Window Display Screen Scale
FFT CH1 Rectangle Full 10.0mVrms/
The last two images are your software with averaging, and without averaging but at 100 MHz.
I do get a reproducible 75 MHz out of the 3x25 with the factory software viewed on the Rigol.
how do you produce that clean 75MHz signal out of 3x25? what factory software?
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A stupid question to ask....
So everyone like Hantek more? Any comments on Atten like ADS1102CML?
I am looking to buy my first 100MHz DSO.....
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I changed my opinion about the measurement system on the Owon (Note to myself: RTFM); mistake due to a stupid visual assumption on my part - and have softened somewhat to the menu system. I've edited the original post, back one page in the thread.
Here are some new .pngs of 1MHz, 50MHz, 80MHz, and 200MHz LVCMOS square waves, made single channel, full sampling rate (except the 1MHz = 500MSa/s) and two FFTs.
Note: Check out the measurements for the 200MHz signal. It lists '?' for frequency in the screen capture (although the counter lists the frequency correctly) - strangely, on the actual screen while running, it lists '200MHz'. Also, the rise time and fall time are listed around ~1.5ns.
Again, after the various hacks around here, one has to wonder how much is actually different between this scope and the SDS8102; the next one in the line.
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Usability was probably on the bottom of the list when they designed this product. What a shame. Btw, have you contacted Owon yet regarding all the issues?
Well, I've softened my view a bit about the firmware (see previous post) - it still has problems for sure - and some features are missing I wouldn't mind having - but I wouldn't go so far as to say usability was at the bottom of their list. Many of the nice hardware features (such as VGA out) are great for usability. Anyway, I'll try to cover all these things in part 2 of my review of the device.
Btw, have you contacted Owon yet regarding all the issues?
No reason to at this point - I can still return the scope for a refund if I like. If I decide to keep it (and I'm still testing and making up my mind), I'll send them my suggestions and any bugs I find - but it appears (from what I can discover online) that Owon doesn't offer firmware upgrades directly to users - they instead follow the policy of dealer upgrades (ship or carry-in plus service charge) - so I doubt they'll make an effort to change 'usability' aspects of the firmware. If I keep the scope, perhaps I'll try to change the firmware myself.
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Well, after reading some of your (marmad) posts, I think I've decided against the SDS7102. The Hantek/Tekway 100MHz looks like the way to go, you get a scope with much more functionality and with some time and effort you can double the BW.
Love the SDS 10Mpts, 8" TFT screen, Trigger Out and VGA Out, 100MHz, 500MS/s (dual channel), Ultra thin design.
But with all these seemingly great specs, the typically "selectable" options like sin(x)/x, and 20Mhz BW Limit, being mandatory????
I like to tell people what I want on my pizza. Not the other way around.
Sad that the SDS looks more like a work in progress than a finished product to me, and it may all be because of firmware.
On that note,
Anyone know where to get a Hantek DSO5102BM or Tekway DST1102B cheap in Canada?
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But with all these seemingly great specs, the typically "selectable" options like sin(x)/x, and 20Mhz BW Limit, being mandatory?
Two things: linear interpolation is something you rarely use - it certainly can be handy for checking sampling around the bandwidth region, but not something you use often in practice. Also, as tinhead mentioned, the Hantek/Tekway doesn't have it either.
The 20Mhz BW limit only came on automatically at the lowest horizontal setting: 2ns. And, strangely enough, I haven't been able to repeat that happening as well. So some combination of settings I had (and I had both channels on at the time) triggered it - but it's not doing it anymore.
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Added speed calculations of USB to PC transfer one page back at original post.
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the 200MHz signal look good, sure -17db level but at least yuo can see something. I don't see a big aplitude non-linearity,
so that's good too. Btw, i see 1GSs/1ksamples, when you change with 200MHz signal attached the memory depth to 10k/100k/1000k/10M how is the picture?
FFT is ok too, with 500MHz span 1GSs is exact what it should be (is there an option on Owon to change sample rate?)
I love the FFT/double window on HanTekway and hate these cheap Rigol implementation, but it is bad
implemented - with 250MHz span only 400MSs and 500MHz span 800MSs - that's too less, everything above
Nyquist is not a signal but alias (so the right two screen divisions are alias and not real signal).
Sure i can patch the firmware to run with 500MSs/1GSs in these two FFT ranges, but i should not compare things
which are not original (oki, Hantek told me they will work on that, whatever this means) - therefore Owon FFT is
looking good (at least from span point of view, about the accuracy i can't tell you anything).
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when you change with 200MHz signal attached the memory depth to 10k/100k/1000k/10M how is the picture?
Just tested this: it's exactly the same at any sample depth - no change whatsoever.
is there an option on Owon to change sample rate?
Yes, you can change it from 1Sa/s to 1000Sa/s in 28 steps.
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As of this point, I've been unable to find time to video record the second part of my review - so, unless I keep the scope, it might not happen at all (but I'll try!). But nevertheless, I've posted many findings in this thread, and this summary should help convey my current feelings.
Summary of Owon testing:
After having used and tested the Owon now for several days I can report that, as far as I can tell, it appears that the Owon hardware is doing what they advertise - and performing to spec. All the new features work as intended (VGA, trigger out, etc) and within the admittedly limited range of ways I have to test the device, it appears to operate like a 100MHz bandwidth, 1GSa/s scope should - providing me with equivalent data that a hacked Rigol DS1052E did. Aside from some small, non-serious bugs which I noticed (but mostly couldn't repeat), the firmware seems to operate fine - I never had a single lock-up or crash - and I DID try to get it to do that ;) I admit I was at first rather annoyed by the firmware (having been spoiled by the better implemented Rigol one [with better usage of English]), but, having used it for awhile now, I've gotten more used to it and it's idiosyncracies - so there are only a few things left which still trouble me.
The main faults I find with the current version of firmware (in descending order of annoyance):
[Minor:]
Show All measurements: kind of a dud - but now that I see that you can display 8 real-time measurements simultaneously outside of the normal screen wave area, this isn't very important.
No linear interpolation of points [or just the ability to turn OFF sin(x)/x]: not a biggie - but it can be handy sometimes.
[Medium:]
No Equivalent Time Sampling: again, not something used all that often - tinhead and alm have pointed out that it's often not well-implemented in cheaper scopes - so while I'd prefer to have the option, if it doesn't work well (or provides erroneous data) it's probably better not implemented.
No SCPI command set (and accompanying VISA driver) - that was a big plus with the Rigol that I will miss. But there are published specs for reading USB data from Owon scopes - so the lack of these things can be worked around for bringing data into Matlab, etc.
[Large:] (these last three are all about not taking advantage of that great big screen - and not necessarily direct somparisons to the Rigol firmware):
No coarse/fine adjust of volts/div: the hardware is already there (push-button encoders) but just not used - why not? Why waste precious screen real-estate by not being able to maximize the wave size(s) to fill the area?
No split-screen window for FFT or zoom: not such a big deal in terms of the FFT, since you can alter sample rates and zoom while it's running, but for marking and searching waveforms, it would really be handy. But then again, there is...
No way to mark, search easily, or jump through wave records: this is just a pain in the ass for a scope with records which can be 10Mpts long. They really need some firmware commands for this similar to what I've seen implemented on the Hantek.
On the plus side:
I owned a Rigol DS1052E for the month previous to this - and even though their firmware is (for the most part) better written and with more features (not in every regard - as mentioned below), I could NEVER go back to the tiny screen and loud fan of the Rigol. BTW, for those of you who wonder about the relative sizes of the screens (Rigol - Hantek - Owon SDS), I've computed and attached a comparison chart - with each screen occupying an equivalent block based on actual display active area - see below.
Other features of the Owon SDS7102 that are missing from the Rigol (aside from 8" screen and quiet fan):
10Mpt sample depth
VGA output
Optional battery
Pass/fail synchronous trigger out
Math A/B [in Hantek also]
Ext. trigger/5 [in Hantek also]
AC line trigger [in Hantek also]
There might be more... that's just all I've noticed.
Lastly, as mentioned in other posts by me, I wanted to buy the scope in Europe if possible - meaning at something close to (or cheaper!) than the Chinese seller's prices. This is possible with Rigol and Owon, but not the Hantek; That means a price comparison, for me, of something like this:
Rigol DS1052E: Base price with European service (but must hack it to get 100MHz bandwidth).
Owon SDS7102: Base price + ~19% with European service.
Hantek DSO5102B: Base price + ~32% with European service [based on tinhead's figues]
In this regard, on a pure bang-for-your-buck level, the Owon seems to me to be the best buy.
So am I keeping it? Hmm... I need a little longer to think about it. Because that's just what I need... another hacking project ;D
Screen_sizes.png (185.95 kB, 600x1350 - viewed 27 times.)
Edit: Changed screen size chart for better representation of Hantek - tip o' the hat to tinhead ;)
Edit2: Revised sin(x)x/linear comment and price chart.
Edit3: Revised sin(x)x/linear comment one last time... I promise ;)
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Usability was probably on the bottom of the list when they designed this product. What a shame. Btw, have you contacted Owon yet regarding all the issues?
Well, I've softened my view a bit about the firmware (see previous post) - it still has problems for sure - and some features are missing I wouldn't mind having - but I wouldn't go so far as to say usability was at the bottom of their list. Many of the nice hardware features (such as VGA out) are great for usability. Anyway, I'll try to cover all these things in part 2 of my review of the device.
Well, I think that the usability is about the way you can use all the features, not the features themselves. It's about user interface and ergonomics, basically how easy it is for the end user to use the product and its features. This is how I understand it.
Anyway, once again thanks for your effort. The summary points will be really helpful for all potential buyers.
Cheers,
Patryk
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Well, I think that the usability is about the way you can use all the features, not the features themselves. It's about user interface and ergonomics, basically how easy it is for the end user to use the product and its features.
Well, I think we more or less agree on it's meaning... I think usability relates to many (if not most) aspects of a product - design, software, firmware, hardware, etc. and how they help or hinder it's use - sometimes for everyone - sometimes for a few. A feature can be related or unrelated to usability - in my case, with poor eyesight, having VGA output increases the usefulness - i.e. ways and times I can use - the scope, but it may not be meaningful to someone else. But anyway, having used the scope for several days, I just don't agree that usability was on the bottom of their list during design and development - I think they made choices - based on money and development time. Some of those choices provide extra usability - some of them get in the way.
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Nicely done, reviewing this brand new piece of testing equipment! I like this kind of boldness in people!
I would never suggest, though, a third party to keep or not such a device. But I will definitely agree with you in that,
"It would be kind of a shame to relinquish the flash new hardware, but I can see by all I've read that the Hantek firmware is better (and the electronics are proven) - and even though I would end up with a DSO without as many initial bells and whistles, I'd have one which is less frustrating and probably more useful in the long term."
Before making decisions, I would firstly need to examine the new hardware and the possible hackability of the firmware. But I realise that your hands are tied in that regard...
Anyway, concerning Owon's optional battery and its silent fan, I think that it would not take much to hack DS1052E's PSU: Adding actually a daughter-board to the stock PSU PCB with a few >90% efficient DC-DC converters (3 x SiC417 SiC413 for the -6V50/+3V35/+6V40 lines and a MAX618+317L for the +15V0 line generation) and a Pico-Power AVR uC (to charge the battery, supervise the input/output voltages and control the fan) to support these functions, too: Given that Rigol's mainboard+display power consumption is ~11W, a battery pack of 10V8/4Ah (using 3*2*3.6V/2000mAh 18650-type cheap Chinese cells) would be enough for four hours of operation per charge, as I have quickly estimated, or five hours respectively by using 2500mAh cells. I guess that hacking the Hantek PSU also (-6V50/+3V30/+6V50/+15V0) should not be much different.
-George
Edit: It is SiC413 (not SiC417, I mistakenly wrote)
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No coarse/fine adjust of volts/div: the hardware is already there (push-button encoders) but just not used - why not? Why waste precious screen real-estate by not being able to maximize the wave size(s) to fill the area?
let's hope the encoder buttos are routed/connected - if so, then there is a chance that this feature will be implemented later.
Knowing the issues with announced LAN which was not ready in time the chance is actually big - when their routed.
No way to mark, search easily, or jump through wave records: this is just a pain in the ass for a scope with records which can be 10Mpts long. They really need some firmware commands for this similar to what I've seen implemented on the Hantek.
yeah, this is very odd
I've computed and attached a comparison chart - with each screen occupying an equivalent block based on actual display active area - see below.
actually your Hantek screenshot is while within dual window mode, when in single mode the menu on
right side can be hiden, so the wavearea is larger.
Rigol DS1052E: Base price with 3 years European service (but must hack it to get 100MHz bandwidth).
Owon SDS7102: Base price + ~18.5% with 3 years European service.
Hantek DSO5102B: Base price + ~33.5% with ? years Chinese service (an oxymoron?).
Hantek - 3years Hantek warranty and if you buy in EU or course with european service, however
the warranty in EU depends on where you buy (elec3i 2yrs)
As for the price:
SDS7102
www.eleshop.nl (http://www.eleshop.nl) - 449EUR (+26% of Rigol price)
www.messgeraete-chemnitz.de (http://www.messgeraete-chemnitz.de) - 458EUR
where you bought it?
Rigol:
batronix.com - 355EUR
Hantek DSO5102B:
elec3i - 569EUR
xxxx - 469EUR (+32% of Rigol price)
Hantek DSO5062B (but must hack)
elec3i - 499EUR
xxxx - 399EUR (+12% of Rigol price)
In my opinion from price/performance ratio Hantek is the best choice (when you can put your finger inside),
and Owon when you need more memory* and can't/don't want put your finger inside.
The screen might be a bit bigger on Owon than on Hantek but without markes/proper zoom "useless",
so let's say no win.
Now depends on what inside Owon it might be possible to hack them too, for sure you will not get extra 1GSs
while hacking 7102 to 8102 but probably it will be possible to change the bw - at least on 8102 which is identical
to 8202 (except bw). These 650EUR for SDS8102 are maybe "much" but if these 10Mpoint memory can be
accessed with 2GSs then definitely worth to pay that price - even if the firmware sucks a bit.
Now i'm even more curious what inside, especially ADCs/Memory/SoC (or only FPGA?)
*more memory - so if you not made a mistake then that's the first low range DSO with real fast memory.
I would love to have 1Mpoint memory sampled with 1GSs, these 400 or 500MSs while within long memory are cheat,
but sure i accepted it because of the low price. And now Owon does have 10M per channel, now i understand
why Hantek is working on 2M option (not that this will change anything, it will be still/probably sampled slow).
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actually your Hantek screenshot is while within dual window mode, when in single mode the menu on
right side can be hiden, so the wavearea is larger.
Oh, I know... I just meant each 'whole' display image compared to the other. I only used the dual window Hantek image because I liked it (nothing to do with side menu) - and it related to my criticism of the Owon firmware. But I had to do research to find the actual dimensions of each screen (not diagonal - but width) so it would be correct. BTW, according to my calculations, the Hantek has the most pixels per mm - 5.25, followed by the Owon at 4.9, and the Rigol with 2.8.
As for the price:
SDS7102
www.eleshop.nl (http://www.eleshop.nl) - 449EUR (+26% of Rigol price)
www.messgeraete-chemnitz.de (http://www.messgeraete-chemnitz.de) - 458EUR
where you bought it?
I got it from eleshop for € 355 (including shipping but excluding VAT - which I don't consider in the price because either I don't pay it - or I get it back later). The guys who own eleshop did an online group buy (with 58 other people) directly from Owon factory from end of May until middle of July - which I just missed - so they gave me a discounted price. If I had ordered the SDS7102 one week earlier during the group buy, I could have had it for € 319 (excl.)
xxxx - 469EUR (+32% of Rigol price)
Who is xxxx? I can't see any any decent price for the Hantek DSO5102B in Europe - on eBay it's € 400 including shipping.
Hantek DSO5062B (but must hack)
Hack to what? 100MHz?
so if you not made a mistake then that's the first low range DSO with real fast memory.
I would love to have 1Mpoint memory sampled with 1GSs
I'm sure I've made no mistake; I checked many times (also reading from the PC 10Mpts one after the next - takes about 2 seconds in total for each upload). Plus the Owon reports the speed and length at the bottom of the screen (i.e. "1GSa/s - 10Mpts") so when you change length or time/div, it changes there. One thing that is possible is that the screen updates are SLIGHTLY slower with 10Mpts enabled - but I'm not sure about that - it may have been my imagination - if it's slower, it's just a tiny bit.
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If you don't want either of the Owon or Rigol... you could try the Atten... I've kind of been curious about it!
http://cgi.ebay.com/DSO-ADS1102CAL-100M-Hz-1G-Digital-Oscilloscope-7-LCD-/330587653468?pt=BI_Oscilloscopes&hash=item4cf88f455c (http://cgi.ebay.com/DSO-ADS1102CAL-100M-Hz-1G-Digital-Oscilloscope-7-LCD-/330587653468?pt=BI_Oscilloscopes&hash=item4cf88f455c)
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If you don't want either of the Owon or Rigol... you could try the Atten... I've kind of been curious about it!
http://cgi.ebay.com/DSO-ADS1102CAL-100M-Hz-1G-Digital-Oscilloscope-7-LCD-/330587653468?pt=BI_Oscilloscopes&hash=item4cf88f455c (http://cgi.ebay.com/DSO-ADS1102CAL-100M-Hz-1G-Digital-Oscilloscope-7-LCD-/330587653468?pt=BI_Oscilloscopes&hash=item4cf88f455c)
no, you don't want this .. CAL series have no long memory : only 40ksamples and this baby have 10Msamples,
a real big display (and not that crap 480x234).
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I got it from eleshop for € 355 (including shipping but excluding VAT - which I don't consider in the price because either I don't pay it - or I get it back later). The guys who own eleshop did an online group buy (with 58 other people) directly from Owon factory from end of May until middle of July - which I just missed - so they gave me a discounted price. If I had ordered the SDS7102 one week earlier during the group buy, I could have had it for € 319 (excl.)
yeah, i remember i saw something about group order as i was looking for someone having then on stock in EU :)
xxxx - 469EUR (+32% of Rigol price)
Who is xxxx? I can't see any any decent price for the Hantek DSO5102B in Europe - on eBay it's € 400 including shipping.
guess who ... i can't do any advertisement because Dave will pruge it and some other ppl here will "purge me" because of unfair competition
Hantek DSO5062B (but must hack)
Hack to what? 100MHz?
you can hack Hantek from 60 to 100, 150 or 200MHz.
Anyway, let's focus on Owon, yeah i do believe you didn't make mistake with the 10Mpoints memory sample on full speed.
That's very nice thing, there are no (yet) competitors on that price level having such fast memory.
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If you don't want either of the Owon or Rigol... you could try the Atten... I've kind of been curious about it!
http://cgi.ebay.com/DSO-ADS1102CAL-100M-Hz-1G-Digital-Oscilloscope-7-LCD-/330587653468?pt=BI_Oscilloscopes&hash=item4cf88f455c (http://cgi.ebay.com/DSO-ADS1102CAL-100M-Hz-1G-Digital-Oscilloscope-7-LCD-/330587653468?pt=BI_Oscilloscopes&hash=item4cf88f455c)
no, you don't want this .. CAL series have no long memory : only 40ksamples and this baby have 10Msamples,
a real big display (and not that crap 480x234).
Everyones needs are different... memory depth is not something I ever have any need for. Mine is always real time probing/triggering.
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Everyones needs are different... memory depth is not something I ever have any need for. Mine is always real time probing/triggering.
and what Owon is doing unreal sampling ? You have no idea what you talking about.
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Rather random question time - can you change the colour of the traces? From your screenshots I suspect I'd find channel 1 almost impossible to use in anything approaching real-time - the red is very dim thanks to the wonders of colour blindness!
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Everyones needs are different... memory depth is not something I ever have any need for. Mine is always real time probing/triggering.
and what Owon is doing unreal sampling ? You have no idea what you talking about.
FFS.. just think about when you use the record length... and when you don't
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Rather random question time - can you change the colour of the traces?
Not random at all.. sounds rather important in your case. But I'm afraid not; the Owon user interface does pretty much all of the things it has to do to fulfill it's specs, but it's fairly sparse on the added extras, like display colors, skins, etc. Keep in mind, they've only been building these scopes for about 3 months or so - it's a brand new line with really great hardware - but the first permutation of software.
I really wish, in these cases, that companies could somehow open source the interface part of their code for user development - and keep the hardware control and output portions separated. There are so many tweaks I'd like to do or add to their interface.
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If you don't want either of the Owon or Rigol... you could try the Atten... I've kind of been curious about it!
But after using an 800x600 display, there is no way I would want to use the 480x234 LCD on that Atten. It is so fantastic having the large display (especially if your eyesight isn't the greatest) - for me, it makes it feel almost like a different piece of equipment than a normal scope (since my portable Tek analog also has a tiny CRT).
There's no way I would settle for anything that wasn't at least 800 pixels wide at this point - trust me, it's a world of difference - not only in the amount of space for the waveform - but the amount of added info you can get all at once. On the Rigol, I often couldn't get enough measurements and wave at the same time.
Anyway, I'm keeping the Owon - or getting the Hantek - there is no other choice for me.
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FFS.. just think about when you use the record length... and when you don't
bullshit, you can select on Owon between 1k/10k/100k/1M/10M, all of them sampled with 1GSs
where ATTEN CAL have only 40k sampled with 1GSs - or if you need memory 2M (on CML model)
sampled with 500MSs ... you see now the diff.
There is no single reason to chose ADS1102CAL, not from ADC point of view, not FPGA, not SoC, never ever memory
and never ever display .. did i forgot something? Yeah, VGA out, less waveform distortion, higher wfrm/s.
The only reason might be price ... but buy cheap means buy twice.
EDIT: oh wait, the ugly red color on Owon sucks, so you ahve two reason to chose ATTEN. But there will be smart
people knowing how to use hex editor and the red color will be gone.
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If you don't want either of the Owon or Rigol... you could try the Atten... I've kind of been curious about it!
But after using an 800x600 display, there is no way I would want to use the 480x234 LCD on that Atten. It is so fantastic having the large display (especially if your eyesight isn't the greatest) - for me, it makes it feel almost like a different piece of equipment than a normal scope (since my portable Tek analog also has a tiny CRT).
There's no way I would settle for anything that wasn't at least 800 pixels wide at this point - trust me, it's a world of difference - not only in the amount of space for the waveform - but the amount of added info you can get all at once. On the Rigol, I often couldn't get enough measurements and wave at the same time.
Anyway, I'm keeping the Owon - or getting the Hantek - there is no other choice for me.
Thats cool, I just suggested it because its screen is bigger than the Rigol. Its going to be hard to find a larger screen than the Owon at the moment in this price bracket.
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FFS.. just think about when you use the record length... and when you don't
bullshit, you can select on Owon between 1k/10k/100k/1M/10M, all of them sampled with 1GSs
where ATTEN CAL have only 40k sampled with 1GSs - or if you need memory 2M (on CML model)
sampled with 500MSs ... you see now the diff.
There is no single reason to chose ADS1102CAL, not from ADC point of view, not FPGA, not SoC, never ever memory
and never ever display .. did i forgot something? Yeah, VGA out, less waveform distortion, higher wfrm/s.
The only reason might be price ... but buy cheap means buy twice.
EDIT: oh wait, the ugly red color on Owon sucks, so you ahve two reason to chose ATTEN. But there will be smart
people knowing how to use hex editor and the red color will be gone.
OK you need to stay off the meds... or get some.
http://www.tek.com/Measurement/scopes/selection/performance/acquisition.html#record (http://www.tek.com/Measurement/scopes/selection/performance/acquisition.html#record)
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OK you need to stay off the meds... or get some.
http://www.tek.com/Measurement/scopes/selection/performance/acquisition.html#record (http://www.tek.com/Measurement/scopes/selection/performance/acquisition.html#record)
funny guy, what will be the next ? link of Tektronix TDS2012C with awsome 2.5k sample memory?
I have here TDS2012 and i'm using it as ashtray since i got my Tekway.
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OK you need to stay off the meds... or get some.
http://www.tek.com/Measurement/scopes/selection/performance/acquisition.html#record (http://www.tek.com/Measurement/scopes/selection/performance/acquisition.html#record)
funny guy, what will be the next ? link of Tektronix TDS2012C with awsome 2.5k sample memory?
I have here TDS2012 and i'm using it as ashtray since i got my Tekway.
There was an excellent reason that when you asked marmad to change the memory depth that the picture didnt change. Its the same reason that I don't really need memory depth. Its a shame about the TDS2012...
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Its going to be hard to find a larger screen than the Owon at the moment in this price bracket.
I mentioned 800 pixels wide which the Hantek's have. And they have models in this price bracket. And they have been hacked, disassembled, and reverse engineered by the guy you're arguing with - a guy who is perhaps the most knowledgeable guy when it comes to low cost DSO's on this blog - so if he says the Atten sucks - I'd believe him that it sucks.
BTW, just as an aside, I think I won't be using the 10Mpts all that often either, but just in case I need to do data logging - or long-term recording looking for a glitch - I sure will appreciate all the memory.
Edit: BTW, the Owon can record up to a 1000 frames at up to a 1000 seconds apart - thats almost 12 days of logging.
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Its going to be hard to find a larger screen than the Owon at the moment in this price bracket.
I mentioned 800 pixels wide which the Hantek's have. And they have models in this price bracket. And they have been hacked, disassembled, and reverse engineered by the guy you're arguing with - a guy who is perhaps the most knowledgeable guy when it comes to low cost DSO's on this blog - so if he says the Atten sucks - I'd believe him that it sucks.
BTW, just as an aside, I think I won't be using the 10Mpts all that often either, but just in case I need to do data logging - or long-term recording looking for a glitch - I sure will appreciate all the memory.
This is just a blog... I've been in this game for quite a few years, I am highly qualified, highly experience and I have never met 'the most knowledgeable guy' who knew what he was talking about all the time. So no-one should believe everything that anyone says on here... not me, not him, not dave.
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Guys, I understand that you guys are very experience, but everyone is free to express their opinion, what he prefers and needs (which I respect). Attacking each other will not help in term of sharing experience and opinion (of course you don't have to agree in all opinion).
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Guys, I understand that you guys are very experience, but everyone is free to express their opinion, what he prefers and needs (which I respect). Attacking each other will not help in term of sharing experience and opinion (of course you don't have to agree in all opinion).
You are right bertchai, but I'll tell you why I come into this thread... its not just about this scope... quite a few reviews on the blog are in the same vane. People get caught up in some kind of academic masturbation on specifications.
Such as the multimeter thread... if you were new to the field you could think that if you didn't spend $250 on a multimeter that had a micro-amps range then what you have isn't worth having. Its nonsense. Most engineers never use that setting - which is why manufacturers don't often include them. Same with true-rms. The truth is that if you didn't abuse it most people could get by just fine for design with a $20 chinese meter for many years.
Same with the scopes. Tektronics sell the TDS1000 and TDS2000 series with small record length's because they know that most engineers don't need single shot postprocessing.
I mentioned the Atten scope. Its easy to rubbish something that has a lower spec, but I know that most engineers never need most of the specifications. Its going to be great for 95% of users design requirements. Maybe its just easier to use - wouldnt that be a good reason to buy it?
I wouldn't have weighed in if what had been said was .... the Atten scope looked great but if you need deep record lengths you should consider something else. Rather... no qualification.. don't know what your talking about... bullshit ... yadaya.
Now if a scope or multimeter is simply not accurate that is something else.
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"No linear interpolation of points: not a biggie - but it can be handy sometimes."
I check the manuals in Rigol DS1000 series, Atten seises, Hantekway DS5120b series.
Only Atten has linear interpolation. The rest only sin (x)/x
Have I missed something? or Hantekway, Rigol has been hacked to include linear interpolation?
;)
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@ gregariz
I partly agree with you that cheaper chinese products should be fine for casual use / careful use. (Actually I am a Chinese. hehe ) But on the other hand, the QC, robustness of these chinese product could be more inferior to big brand products like fluke, tek, and they simply die over the time even not used. If I can afford, of course DSO from tek, LeCroy, etc, will be wonderful. You can trust your measurements without any doubt anytime (especially for rookies like me). When budget is a concern, chinese DSO could be a good choice, but I can see that not all chinese brands are as good and hopefully find something good that I can still trust at low price.
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There's a great quote here somewhere..... oh yeah,
"I know that I know not" - Socrates
Perhaps take a page from a true master?
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Hantek 2500 wfrms/s
Rigol 2000 wfrms/s
Owon ?
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I wouldn't have weighed in if what had been said was .... the Axxxx scope looked great but if you need deep record lengths you should consider something else.
Ok, seriously already, in a review thread of the Owon SDS7102 - a few posts after a long summary by me in which I specifically mention I don't like tiny screens - and post a screen size chart to reiterate that point - then end with a price comparison between the Owon and the Hantek, the other scope (with large screen) that I'm considering purchasing - you post a suggestion for a different cheap DSO with a tiny screen and a link to it's purchase. To me this indicates one or more of the following:
a) You didn't read my summary.
b) You are unaware of the basic features of the DSO, such as screen size.
c) You are attempting to hijack the thread to a discussion about it since you are interested in it yourself.
d) You work or are connected to the company or the people that sell it.
In any case, that is the context. So, given that, perhaps you can understand the reactions to your non sequitur post. So PLEASE, in the interest of the thread, stop mentioning this other DSO here which has no bearing, connection, or relevance to anything I've written in my findings or review. Thanks.
I am highly qualified, highly experience and I have never met 'the most knowledgeable guy' who knew what he was talking about all the time.
You'll notice I wrote "perhaps the most knowledgeable guy" in my original post - indicating that I've read his posts about the innards of cheap Chinese DSOs and, IMO, he has a lot of knowledge about the subject.
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Hantek 2500 wfrms/s
Rigol 2000 wfrms/s
Owon ?
I don't know - and unfortunately I don't have the correct equipment to test it easily. But I can say, observationally, that refresh rates are very snappy; they don't seem to change due to memory depth (or if so, it's a tiny amount); and they don't get screwed up (flickering) by the act of accessing the scope from the PC, as the Rigol does in it's latest firmware. Also, I have heard through channels that the Owon uses a good Samsung ARM MCU - the same family as the Hantek.
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I check the manuals in Rigol DS1000 series, Atten seises, Hantekway DS5120b series.
Only Atten has linear interpolation. The rest only sin (x)/x
Strange... I just had the Rigol scope and I could have sworn that I remembered turning off sin(x)/x on it. If not, my mistake - the comparison is not valid - I'll edit the post.
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I check the manuals in Rigol DS1000 series, Atten seises, Hantekway DS5120b series.
Only Atten has linear interpolation. The rest only sin (x)/x
Strange... I just had the Rigol scope and I could have sworn that I remembered turning off sin(x)/x on it. If not, my mistake - the comparison is not valid - I'll edit the post.
May be I am wrong. I never have a Rigol scope. I was checking and comparing manuals to see if I buy this SDS7102 I will be missing anything.
May be Rigol did have the choice of turning off sin(x)/x but they just never update the manual. You know, after all, still cheaper chinese DSO.
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Latest update:
I've decided to keep the Owon - after doing some research and investigation into the hardware they're using. I'll post Video Review Part 2 tomorrow - demonstrating the firmware - and explaining my findings.
It was a tough call between it and the Hantek - I might have gone with the Hantek if I hadn't gotten such a good price on the Owon - but that's just personal preference - hopefully the final review and summation will help others in the same boat as I.
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http://www.ebay.co.uk/itm/New-100M-OWON-Digital-Storage-Oscilloscope-SDS7102-1G-s-/280720232929?pt=BI_Oscilloscopes&hash=item415c3ad1e1 (http://www.ebay.co.uk/itm/New-100M-OWON-Digital-Storage-Oscilloscope-SDS7102-1G-s-/280720232929?pt=BI_Oscilloscopes&hash=item415c3ad1e1)
£315 uk inc p&p.
Nice review looking forward to teardown (hack?) ;D
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Its good the measuring capabilities of the Rigol ~= Owon with the main differences being screen size, frequency response and some ergonomics. In the end Owon cost about $100 US more, even with favorable price you found it at, so you are getting more scope for the money plus the larger screen of great importance to your basic usability.
I think the Rigol does a crude linear interpolation if sinx is turned off. There is a very interesting discussion here with some excellent analyses done by eevblog's jahonen using very righteous gear.
https://www.eevblog.com/forum/index.php?topic=276.15 (https://www.eevblog.com/forum/index.php?topic=276.15)
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Nice review looking forward to teardown (hack?) ;D
Sorry, no teardown - I'm in my golden warranty period :) just harmless investigation, help, and data from some very reliable sources.
Its good the measuring capabilities of the Rigol ~= Owon with the main differences being screen size, frequency response and some ergonomics. In the end Owon cost about $100 US more, even with favorable price you found it at, so you are getting more scope for the money plus the larger screen of great importance to your basic usability.
A theory has been put forth, based on some data, that Owon started development of the SDS line after Hantek bought Tekway. The new Owon SDS line has some fairly impressive hardware, but clearly they have rushed them to market (evidenced by unfinished features like the LAN port; the slightly underdeveloped firmware; and low introductory prices). Why? They know that Hantek is releasing the BM and BMV line in a couple of months (with more memory) - plus the price of the low-end Rigols has been coming down, so it's possible Rigol is also planning a launch of a new product sometime soon. It could be an interesting few months for low-end DSOs. Unfortunately, I need one right now and can't wait to see how it shakes up ;)
I think the Rigol does a crude linear interpolation if sinx is turned off.
Thanks for clarifying that, saturation. I thought I remembered the ability to turn it off on the Rigol.
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marmad, please keep posting on your future adventures with your DSO. There are many local champions on eevblog for various devices I think further findings on your new toy will help us all.
Here's a sample of the sinx off and the Rigol's presentation of sine waves with increasingly slower sampling rates and how it affects waveform integrity as it approaches Nyquist limits.
https://www.eevblog.com/forum/index.php?topic=2323.msg32022#msg32022 (https://www.eevblog.com/forum/index.php?topic=2323.msg32022#msg32022)
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http://www.ebay.co.uk/itm/New-100M-OWON-Digital-Storage-Oscilloscope-SDS7102-1G-s-/280720232929?pt=BI_Oscilloscopes&hash=item415c3ad1e1 (http://www.ebay.co.uk/itm/New-100M-OWON-Digital-Storage-Oscilloscope-SDS7102-1G-s-/280720232929?pt=BI_Oscilloscopes&hash=item415c3ad1e1)
£315 uk inc p&p.
Nice review looking forward to teardown (hack?) ;D
Maybe you can buy directly from factory 1pcs "sample". It is more cheap! And it is 99.3% more reliable and reputable.
And they deliver by DHL. There you get also Factory warranty.
If you buy from whoever seller... ok you stay just with your own. Factory warranty do not move to third party, it is only for original buyer. (Xiamen Lilliput..): "This warranty only applies to the original purchaser and is not transferable to the third party."
Who you trust more. Owon or noname seller in ebay.
Also if use payPal you loose some becouse PayPal use very poor currency exchange rate. And also you loose becouse PP fee is in price. Of course you can buy also from Owon's small or bigger reseller and you get maybe real customer care and also aftersale customer care. Also these noname sellers do not make any kind of test. You may get fail unit or it may fail after third power up. Yes you can try refund etc.. My recommendation is to buy real reputable seller. (as me or some one other but I have not any Owon - and my prices are higher - lot of. Becouse some customers want real customner care before and aftersale and all know: there is no free dinners - exept in China .. haha..)
ADD: Always need remember that QC is not well arranged in most of chinese factories. So there is "high" risk to buy these directly and specially from ebay or other unknown seller who even do not know anything about machines they sell. 99% they do not do any kind of test. They are just as dropshippers wihout any responsibility. Only what you can do is give negative feedback and in very bad case you can open ebay problem solving system and loose time and get your mind frustrating and loose your money or lot of time or both.
In my area I sell "something" and all what I sell go first full tests including enough burn in time and stress.
Price is more than cheapest. If still after all customer get bad unit or later warranty issue, he/she call me. In DOA case he have in most cases working unit inside 72 hours or faster in distance is close and can personally pic-up. All can understand that this kind of care can not do as "free dinner". I have counted DOA's %. Maybe bad luc and also single case but around 20%. (I know it was littlebit bad luck becouse I know something what is bacround for some problem..) Maybe 5-10% is better estimate. But who know what happend whole 3 year warranty time. We know it after years.
Simple one solution is.
Buy 10 and sell 6. Keep 4 units for fail change. Include this to selling price. I do not want any unsatisfied customer. One unsatisfied customer may pay 100 customer to me and I can not never get bac customer who is fully disappointed.
Keep 1 satisfied customer (so he some day buy more something) cost 1 money. Get new customer cost 20 money. Get fully disappointed customer back cost 400 money or is impossible. If one angry but other peoples trusted customer is extremely disappointed he may cost your whole business.
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Nice review looking forward .... hack?
yes, i will take closer look on firmware soon, so if there is a way to hack something i will publish it here in forum.
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Factory warranty do not move to third party, it is only for original buyer. (Xiamen Lilliput..): "This warranty only applies to the original purchaser and is not transferable to the third party."
if so then i would not buy from a seller not located locally, there is always a very high risk with
chinese products to get even from a factory DOA units. Personally i had already such devices - in principle
from any manufacturer, especialy when BGAs inside (soldering issues). Having good ework and Reflow equipment
not a big deal for me, but without i would be screwed up.
Btw, where you have this warranty information?
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Btw, where you have this warranty information?
It is stated in User manual (June 2011 edition). Just after front side and contact information: "General Warranty" what whole text is good to read carefully. (I do not know how it is interpreted in practice. - I have not yet company explanation for this)
Example, warranty is only for labor and parts. Customer is fully responsible for all shipping costs to repair service. But also warranty time is clear, 3 years. (not as Hantek who have some confused information between 2 years and 3 years.)
Btw, Hantek (if use repair service in china). DOA unit. Hantek pay all shipping (I do not know how they refund customer to hantek shipment what is first step). Not specified what is exacly accepted as "DOA" unit. Other warranty fails: Customer pay shipping to servce (in China). Hantek ship free to back. Also Hantek sell "out of warranty repairs service" where customer pay whole two way shipping and work and parts. (cheap, exept shipping). I do Hantek warranty repairs - but only for units what I have sell. (so I do not exactly know how it works if customer need direct factory repair servic)
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Example, warranty is only for labor and parts. Customer is fully responsible for all shipping costs to repair service. But also warranty time is clear, 3 years. (not as Hantek who have some confused information between 2 years and 3 years.)
If so, then Eleshop (where I bought my SDS7102 - and which covers the first year of the Owon warranty themselves), has to either do their own repairs or eat the shipping costs back to Owon.
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It is very easy in some cases. (I do not know eleshop and do not know anything what is they selling and pricinc policy and how they really do after sales customer care.)
But, I know some companies. How they do with example chinese machines.
Add 10% or littlebit more to price. If one of 10 unit fails. Put it to waste station or evacuate spare parts. And give new one to customer if can not easy repair immediately. Only simple rule, do not put customer to troubles. Do it "behind" and keep customer satisfied if he/she is normal honest people. Always there are real "trouble" peoples but so what.. if he is wrong - pay it and make him satisfied and he shut off his big mouth and both win. It is just win win. (in most cases). Keep it all included price. If real fail persent is only 2 or 5% no one can not see it in price. But how big value give customer who every place tell after issue how fine service he get from this xx.
But now it go wrong becouse many peoples look _only_ price. Oh I can buy 5 money less in ebay... you are robber
with high prices.
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Add 10% to price. If one of 10 unit fails. Put it to waste station or evacuate spare parts. And give new one to customer if can not easy repair immediately.
Sounds logical... and I think, as customer, worth that 10% for the first year insurance, since most of us know that electronics tend to fail right near the beginning - or else right near the end - of product life.
Eleshops current price (excl. VAT but including shipping in NL) is approx. $524 (buying $ at 3% credit card rate). If Sergey's pricing is correct, than single unit from Owon is (with Russian market discount ;) ) $390 plus $75 shipping = $465. 10% on top of that = $511.50 (not too far from the Eleshop price, which is ~12.5% on top) - cheaper than 2x shipping to Owon if something goes/is wrong.
And I did read in the group buy comments at samenkopen.nl that one or two people got units with malfunctioning fans - so, like any kind of insurance, you take a risk or pay more money.
P.S. No affiliation with Eleshop - other than buying my Owon from them.
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@tinhead: "interessting, Owon told me 450$ per unit (+VAT+ ship.)"
Did Owon told you how to pay? I am located in Hong Kong, and Owon told me it is best to buy directly from them as there is no local distributor here. I was told to TT $ directly to their HSBC bank.
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www.messgeraete-chemnitz.de (http://www.messgeraete-chemnitz.de)
Thanks for this link... they have a good price on the SDS battery - about € 13 cheaper than Eleshop; I think I will get it from them.
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Here's the second part - a look at some of the faults and features of the firmware:
Edit: See Page 1
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@tinhead: "interessting, Owon told me 450$ per unit (+VAT+ ship.)"
Did Owon told you how to pay? I am located in Hong Kong, and Owon told me it is best to buy directly from them as there is no local distributor here. I was told to TT $ directly to their HSBC bank.
I'm not tinhead but I know and answer "over" tinhead, sorry.
Afaik, payment method is "T/T advanced" directly to bank. You need they send proforma invoice to you and there is total. You pay it as T/T directly on bank desk in HK or directly from your account using netbank. Write money tranfer note field your order identification what are also stated in proforma invoice. Also remember pay yourr and recipient bank possible fee.
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I like this review and I also bought the scope at the eleschop in the Netherlands a few weeks before marmad. Its quite hard to get the Rigol in the netherlands, for a decent price, only one firm had it but it was not in stock.
I have one question for marmad. I noticed the following if the scope has a probe connected to one of its inputs it picks up the backlight inverters. The signal is approximately 4 to 8 mV. I also read in other threads that almost all cheap scopes suffer from this problem. How, does yours compare in this.
Some remarks.
The BW limit is only active at 1 and 2 mV/div not at 5 mv/div.
Large memory why/why not? Try to solve a power up problem with only 25 kpoints of memory. It is great to see your power supply switch on and capture the whole event.
P.s. Dave keep up the good work.
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very nice review. this scope looks like one for me. :)
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Some remarks.
The BW limit is only active at 1 and 2 mV/div not at 5 mv/div.
My opinion is that it is only default. With all V/div you can shut BW limit on or off.
1-2mV/div it go on by default but you can shut it off. (Rigol do this, Hantek do this etc)
Personally I do not like these automatic defaulting on the fly. If I select BW limit on or off, scope need keep it as long as I change it by my self. This is normal in (all) "old" professional scopes, specially old good analog scopes.
User is master, scope is slave. User do settings, scope only follow users. Exept "auto setup".
I do not like that scope change my some settings if I change other setting.
If there come conflict settings scope must not change something itself for avoid conflict, it need only disable conflict setting and/or informate about conflict.
But some like apples some oranges.
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I have one question for marmad. I noticed the following if the scope has a probe connected to one of its inputs it picks up the backlight inverters. The signal is approximately 4 to 8 mV. I also read in other threads that almost all cheap scopes suffer from this problem. How, does yours compare in this.
Do you mean with probe floating - no connection to anything?
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Three scenarios.
1. Probe floating (no problem)(not sure though need to check)
2. Probe ground clip connected to the circuit under investigation
3. Probe and ground shorted.
In the last two scenarios the problem arises. The inverter can be picked up easily with the pig tale, ground connected to the tip, just move the probe in front of the operation panel of the scope. I also saw Dave do this with a Tektronixs scope.
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I noticed the following if the scope has a probe connected to one of its inputs it picks up the backlight inverters. The signal is approximately 4 to 8 mV. I also read in other threads that almost all cheap scopes suffer from this problem. How, does yours compare in this.
this depends on construction and backlight type, it can be also coming from other components
like PSU here on Hameg HMO3524 (which is actually not cheap model)
Hameg HMO3524 with a bad power supply (https://www.youtube.com/watch?v=pYVr9Kgwf_8#)
Then of course third part EMV, as i tuned PSU on Hantek i had to shut down most everything here
to not pickup something what not produced by DSO itself, therefore only a test in controled EMV save
envoronment is something i trust.
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If I select BW limit on or off, scope need keep it as long as I change it by my self. This is normal in (all) "old" professional scopes, specially old good analog scopes.
If I select BW limit on or off, scope need keep it as long as I change it by my self. Many analog scopes had less bandwidth at the highest vertical sensitivities, because an extra gain stage was switched in. The BW limit light might not come on, but that's just because the technology for this would be too complex. For example, the Tek 453A had 60MHz BW from 20mV/div, but only 40MHz at 5mV/div. And even less with both channels cascaded for higher sensitivity. The Tek 454 is similar.
Limiting the bandwidth is a nice way to hide your horrible noise performance at low signal levels. Plenty of big boys do the same.
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Hm, my Rigol doesn't turn on BW limit on the highest sensitivities.
I am the Master :)
DS1052E software hacked to 100MHz, firmware 00.02.02 SP2
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You really showcase the usability very nicely. A technique I use is my forefinger and thumb on my right hand in a kind of reverse "L", so I can use my thumb for the buttons on the right screen side of the Rigol, while using my pointer finger for the buttons on the main face; I think with the Owon you can do similar between the buttons on the side of the screen and the bottom, this minimizes moving your hand around.
Given the Euro~ 60 difference between both, the Owon is a better deal given that at the very minimum its a match for the Rigol in measurement fidelity, plus natively 100 MHz.
Here's the second part - a look at some of the faults and features of the firmware:
[/url]
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If I select BW limit on or off, scope need keep it as long as I change it by my self. This is normal in (all) "old" professional scopes, specially old good analog scopes.
If I select BW limit on or off, scope need keep it as long as I change it by my self. Many analog scopes had less bandwidth at the highest vertical sensitivities, because an extra gain stage was switched in. The BW limit light might not come on, but that's just because the technology for this would be too complex. For example, the Tek 453A had 60MHz BW from 20mV/div, but only 40MHz at 5mV/div. And even less with both channels cascaded for higher sensitivity. The Tek 454 is similar.
Limiting the bandwidth is a nice way to hide your horrible noise performance at low signal levels. Plenty of big boys do the same.
Yes. Example 2465 give (-3dB) 400MHz 5mV to 5V but "only" 350MHz with 2mV/div
Also temperature affect to BW.
But there is 20MHz (actually littlebit under) BW limiter button, user selectable setting. It follow My selection. I'm master and scope is just slave. This is scope settings. Amplifiers natural BW you can not select as user.
I mean user settings what user made as he use instrument. These need no change by scope, I still keep right to think that people is more clever than oscolloscope who is designed with some peoples who have lot of lack of enough experience.
But this is my opinion just as I like more oranges than apples.
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Are there some posibility in Owon that you set example 1us/div, 1k memory and then you can adjust samplerate somehow keeping other settings fixed.
No, the sample rate is fixed by formula.
Some examples:
| --------------- | --------------- | --------------- |
| 1ms/div | 1ch | 2ch |
| --------------- | --------------- | --------------- |
| 1k | 50kSa/s | 50kSa/s |
| 10k | 500kSa/s | 500kSa/s |
| 100k | 5MSa/s | 5MSa/s |
| 1M | 50MSa/s | 50MSa/s |
| 10M | 500MSa/s | 500MSa/s |
| --------------- | --------------- | --------------- |
| 10ns/div | 1ch | 2ch |
| --------------- | --------------- | --------------- |
| 1k | 500MSa/s | 1GSa/s |
| 10k | 500MSa/s | 1GSa/s |
| 100k | 500MSa/s | 1GSa/s |
| 1M | 500MSa/s | 1GSa/s |
| 10M | 500MSa/s | 1GSa/s |
Is it possible to "zoom out" so that whole memory is on the screen? (useful in clitch hunting and extremely amazing if it is implemented) I know it can do of course in stop mode only changing timebase.
Not quite - no fine control for timebase. At 50ms/div, with 10Mpt depth, you are sampling at 10MSa/s, so memory = 1.0 second of time, but screen is ~15 div wide - so display = 0.750 second.
maybe waveforms/s can calculate using trig out and knowing samplerate ans memory depth it mey give good image for "dead time" what ALL digital oscilloscope have less or more.
Yes, I thought last night about whether this might be possible myself. With 1kpts length, trigger out (no pullup - directly connected to CH2 - triggering itself) is producing something between ~17 - 25Hz on the trigger frequency counter (depends on sec/div, on-screen menus, etc); with 10MPts, between ~13 - 20Hz. What's interesting is that the duty cycle is ALWAYS displayed as +38.6% and -61.4%, regardless of anything else - even though it's perfectly 50/50 on the screen - so perhaps an indication of "dead time"? I don't know enough about this subject to comment intelligently - I just post this data and let you guys do the hard work ;)
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The inverter can be picked up easily with the pig tale, ground connected to the tip, just move the probe in front of the operation panel of the scope.
Sorry, this doesn't seem to be happening on my scope. I only pick up inverter noise if put the probe (ground to tip) at the back of the scope directly near the inverter - but then I also start picking up PSU noise as well. Perhaps you have a shielding/ground problem inside?
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You really showcase the usability very nicely.
Thanks, saturation... and for your comment at youtube :)
A technique I use is my forefinger and thumb on my right hand in a kind of reverse "L", so I can use my thumb for the buttons on the right screen side of the Rigol, while using my pointer finger for the buttons on the main face; I think with the Owon you can do similar between the buttons on the side of the screen and the bottom, this minimizes moving your hand around.
He, he... yes, I started to develop this technique naturally (evolution?) because of the menu system. It's just a shame that it seems the people who often design interfaces are not the people who use them.
Given the Euro~ 60 difference between both, the Owon is a better deal given that at the very minimum its a match for the Rigol in measurement fidelity, plus natively 100 MHz.
It would be great if someone who has the right test equipment (Dave?) could do a rigorous comparison of the Rigol DS1102E, Hantek DSO5102B, and Owon SDS7102. The Owon is using a single chip ADC08D500 clone - so no interleaving at 2ch-500MSa/s (or overclocking) - thus the possibility of better signal fidelity (less distortion caused by clock jitter or interleaving) than the competitors exists.
Edit: Added italics to avoid trouble with the various camps ;)
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marmad: Thank your nice rewiev and work with this scope.
At 50ms/div, with 10Mpt depth, you are sampling at 10MSa/s, so memory = 1.0 second of time, but screen is ~15 div wide - so display = 0.750 second.
Can you really do this with scope capturing all time (not only in stop mode)?
I mean that 75% of 10M captured data is all on the screen and scope is capturing (example with 50ms/div?)
Later (i'm quite sure) I can also test this scope with professional High-end test equipments. Also compare with Hantek but not anymore with Rigol becouse I stop totally with this brand.
But before I get first Owon's to my desktop it takes maybe 2 - 4 weeks.
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Can you really do this with scope capturing all time (not only in stop mode)?
I mean that 75% of 10M captured data is all on the screen and scope is capturing (example with 50ms/div?)
Well, it appears it does - but two things to note:
1) I just assumed "dead time" means the time during which the scope can't capture new data, because it's otherwise preoccupied. Is this correct? If so, I don't know how long this dead time is when putting 75% of 10M to screen.
2) I don't know how the scope is translating 7,500,000 horizontal points to 800 - certainly a lot of data gets lost - so I'm not sure how useful this is. If looking for glitches, I think it would be better to use pass/fail - either real-time or on recorded waveform - or else upload data to PC and post-process there.
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A couple of further findings perhaps of interest:
I was just watching Dave's review of the Agilent 2000 X Series Infiniivision - where he shows the Rigol aliasing on a 20MHz sine wave. I thought I'd see what the new Owon did under the same circumstances. Owon also aliases when the sample depth is set 1k, 10k, 100k, or 1M (on lower sec/div settings), but interestingly, it doesn't alias the 20MHz sine on any sec/div setting when the sample depth is set to the full 10M.
Also playing around with slow sweep times - if you set the depth to 10M and, for example, 5s/div - you get 100 seconds of samples (each full sweep) spaced 10us apart - in fact, when you stop sampling and zoom in, the Owon switches from vectors to dots when you reach the range (or below) that corresponds to sample speed (i.e. 10us in the last example). Since the Owon can do up to a 100s/div sweep, that means you can use the 10M of samples over 33.3 minutes, spaced 200us apart - which makes it a kind of nice, alternative frame recording (although sample points instead of full frames). Another reason to like a lot of sample memory ;)
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i've just tested the PC software, and hmm (i just don't like java crap), for some reason something simple
like 1khz sine wave can be show but the FFT is useless (testing it with the example waves from the PC software).
Can you do something for me and export 1khz sine wave data let say sampled with 1k, 10k and 100k memory depth?
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i've just tested the PC software, and hmm (i just don't like java crap)
Yes, I don't like their PC software at all... I can see I have some work for me there sometime in the future. The good thing is USB 2.0 speeds - so there is the possibility of doing something real-time and nice (at lower sample depths).
Can you do something for me and export 1khz sine wave data let say sampled with 1k, 10k and 100k memory depth?
No problem... any particular timebase (sample speed)?
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Yes, I don't like their PC software at all... I can see I have some work for me there sometime in the future. The good thing is USB 2.0 speeds - so there is the possibility of doing something real-time and nice (at lower sample depths).
yeah, but they should really change the driver from libusb to something more efficient.
No problem... any particular timebase (sample speed)?
let say 200us/div
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yeah, but they should really change the driver from libusb to something more efficient.
There is this: http://sourceforge.net/projects/owondriver/files/ (http://sourceforge.net/projects/owondriver/files/) but I haven't tested to see if it works for the SDS line yet. Another thing on the pile of things to do ;)
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I just placed order directly from Owon in China. Let's see how long it will take to arrive. :)
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I just placed order directly from Owon in China. Let's see how long it will take to arrive. :)
If you can, please let me know what your series and version number are when you get it: Utility -> Function -> Config -> About
Thanks!
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I just placed order directly from Owon in China. Let's see how long it will take to arrive. :)
If you can, please let me know what your series and version number are when you get it: Utility -> Function -> Config -> About
Thanks!
Definitely. I actually order the 8102. But will still post. I was going to get the 7102, but then I was tempted by the 2Gs/s. :P
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Definitely. I actually order the 8102. But will still post. I was going to get the 7102, but then I was tempted by the 2Gs/s. :P
Great (I was also tempted - but I got very a good price here for the 7102 I couldn't refuse)... don't forget to post a review here! ;)
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I'm now littlebit confused:
Some OWON product catalog have small differencies. (some catalog have text March 2011 some not but both have SDS serie
Also one italian seller "sglabs" sell SDS7102 and his picture looks like RS232
Also http://www.zeitech.de/OWON-SDS7102-100-MHz-Oszilloskop (http://www.zeitech.de/OWON-SDS7102-100-MHz-Oszilloskop)
And same for SDS8102 model:
http://www.zeitech.de/OWON-SDS8102-100-MHz-Oszilloskop (http://www.zeitech.de/OWON-SDS8102-100-MHz-Oszilloskop)
Option RS232 (satandard), or VGA with extra price?
What is normal standard model today if buy just SDS7102 without any "option"?
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I'm now littlebit confused:
Some OWON product catalog have small differencies. (some catalog have text March 2011 some not but both have SDS serie
Also one italian seller "sglabs" sell SDS7102 and his picture looks like RS232
Yes, I was confused beforehand as well - because I also saw pictures with RS-232 port instead of VGA. Also, some sites list some models as having COM port AND VGA - and others don't even list the VGA (see saelig.com). Also, on the case, the port is identified as COM/VGA - but I don't think there are any COM port connections on the VGA connector (even though there are 4 free pins on a normal VGA connector) - so they must have designed that there (awhile ago) when they hadn't made up their minds how to use it yet for which models - but I don't think there are any COM port models (see below).
Basically, I think the confusion is due to Owon not firming up their specs before starting to advertise (but I'm not sure). But I know that the 6062 does NOT have VGA or RS-232, and all the models >=7102 are supposed to have VGA as standard. It's strange that one site is offering it as an option (have they even seen the scopes?) - I've never seen that before - how does an RS-232 connector even fit in the VGA solder pads on the main board? It would require different main board or strange adapter. And there is NO mention of RS-232 or COM port in the manual for the SDS line. My mistake, actually it's mentioned twice: in the pictures of the different sides of the case - and in the specs at the end of the manual "Communication port: USB2.0, USB for file storage, VGA port or RS-232".
Check the spec chart at Owon: http://www.owon.com.cn/eng/smartDS.asp (http://www.owon.com.cn/eng/smartDS.asp) - I think it is correct (except for VGA on 6062).
http://www.zeitech.de/OWON-SDS8102-100-MHz-Oszilloskop
Don't buy from them - their prices are HIGH! (Their price for the battery also sucks - double the price mentioned below.)
BTW, best price that I've seen so far (in EU) for SDS7102 is still http://www.eleshop.nl/nieuwe-serie-owon-sds7102-p-480.html (http://www.eleshop.nl/nieuwe-serie-owon-sds7102-p-480.html)
And best price I've seen so far (in EU) for SDS8102 is http://develissimo.com/online-shop/category/measurment/digital-oscilloscopes/ (http://develissimo.com/online-shop/category/measurment/digital-oscilloscopes/) (they have best price on battery, too).
What is normal standard model today if buy just SDS7102 without any "option"?
As far as I know, everything I mentioned in my review (I didn't buy any 'options') - and my unit is approximately 4-5 weeks out of the factory.
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Of course I think no one buy this .de store. Look what is soft carry pack price also. hehe.
But these and lot of other sides I find becouse I make some study what all info I can find and how much there is maybe disinformation. Some info and pics still let me littlebit thinking that if some early "zero" version have difference. But also it may be that peoples mix models and pictures.
http://i00.i.aliimg.com/img/pb/266/005/392/392005266_113.jpg (http://i00.i.aliimg.com/img/pb/266/005/392/392005266_113.jpg) (this I loose where it was but searching was SDS7102 and original place some Alibaba?.
Then eleshop and this picture is where is: Nieuwe serie: Owon SDS7102
but picture is: http://www.eleshop.nl/images/product_SDS6062-a.jpg (http://www.eleshop.nl/images/product_SDS6062-a.jpg)
If people do not look picture address inserted on the side... he may think it is 7102 picture.
It is very fun to use google picture find and follow these links..
How average people who maybe have not lot of experience about buying and equipments can know what they get if they buy from some place without amount of letters where need ask every sigle detail. ;)
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So maybe the 6062 does have RS-232 port (different main board as well?), but scopeman (who reviewed it in another thread) didn't mention it -
and it's not mentioned in the manual. But for sure, the upper models have VGA - why would anyone want RS-232 instead? Owon is not supporting SCPI commands or GPIB - so no reason - faster and better to use USB 2.0.
Also, this image (http://i00.i.aliimg.com/img/pb/266/005/392/392005266_113.jpg (http://i00.i.aliimg.com/img/pb/266/005/392/392005266_113.jpg)) is definitely early-production version of case - no COM/VGA marking, LAN port soldered in (ha!), encoder knobs different, and there are no colored circles around the div knobs. I think this is for publicity early on - in fact, no electronics inside that case ;D
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Yes it was amazing internet round trip!
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BTW, it's clear from all the info posted in this thread that Owon made special rates available in the last 2 months (I wonder what the manufacture cost is?) in order to get the SDS line to market and selling quickly - and that now (or sometime soon) they want to raise the prices a bit - so for anyone interested, it might be a good idea to buy soon.
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I will answer to my own question about VGA.
SDS7102 (maybe all SDS) have factory standard version where is RS232. VGA is factory option! (and also not retrofit option afaik) Also this version is littlebit higher price. Now only problem is Owon product catalog and technical specs where Battery is stated as option but VGA is listed without text "option". For avoid misundestanding they need correct this. Reseller/distributor may have both versions and they need carafully tell what version they sell. I do not know what is exactly meaning that VGA is shared with RS232 and VGA is option.
Maybe later I have posibility to test it in real. But if someone have allready this version it is nice if he can test if there is hidden RS232 implemented in VGA connector?? (please someone who have possible to test: check and share this information after it is exactly sure how it is. (who need RS232 is other question - and what for it it is.)
This question rise becouse someone tell me that he have order one SDS version and he was asked extra price for VGA. Now it is clear. It is factory option today.
Look carefully that buy right model from distributor/reseller. (Some seller may have only one version, with or without VGA.
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SDS7102 (maybe all SDS) have factory standard version where is RS232. VGA is factory option!
Strange... well, I was never asked if I wanted that option - but I would have returned it if it didn't come with VGA - since that was how I saw it publicized online.
Also this version is littlebit higher price.
Different interconnect board or no Chrontel chip, etc, installed. Don't get the model without VGA - that would be a bad choice. €20 for VGA option out on SDS series - $400 for VGA option out (and LAN) on Agilent 2000 series?
Now only problem is Owon product catalog and technical specs where Battery is stated as option
Problem with English... battery is not an OPTION from factory - the scopes do not come delivered with battery. All models can OPTIONALLY run from battery power if you buy separately the SDS battery.
But if someone have allready this version it is nice if he can test if there is hidden RS232 implemented in VGA connector?? (please someone who have possible to test: check and share this information after it is exactly sure how it is.
Just checked the VGA output pins with scope - no activity or voltage on the NC pins (but probably needs jumper installed inside if using same main board). Vertical Sync is 60Hz - so that is the refresh rate of the external monitor.
(who need RS232 is other question - and what for it it is.)
It's just a different way to connect PC to scope (it's the same on the Rigol) - easier for some people to write software for (especially if re-using drivers) - but slower than USB 2.0 connector.
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Strange... well, I was never asked if I wanted that option - but I would have returned it if it didn't come with VGA - since that was how I saw it publicized online.
Yes, you did not buy from factory, you buy from reseller who have select this model from factory.
VGA is not stated as "optional" but still it is exactly factory option. You buy RS232 version OR VGA version from factory and RS232 version is standard and VGA version is "optional". Understanding problem? I can explain better if need.
Problem with English... battery is not an OPTION from factory - the scopes do not come delivered with battery. All models can OPTIONALLY run from battery power if you buy separately the SDS battery.
Yes. And it is stated in papers (optional)
It's just a different way to connect PC to scope (it's the same on the Rigol) - easier for some people to write software for (especially if re-using drivers) - but slower than USB 2.0 connector.
Of course I know this. I have more than 35 years experiance in industry designing systems and doing labs. I have do lot of work in time when no one have heard about USB. I have used lot of different serial connections, not only just RS232 and I know exactly what they are and how to use these and what for. Question is now... who really need RS232 in this scope so much that factory have selected this as "standard" model. Today I think RS232 can be "option". I know some few reasons it may be sometimes useful but less and less today. Also I know how poor is PC/Windows serial port hassle. It is just nearly as garbage design - thank Bill gates and MSDOSWindows. If you like you can find Agilent note about SCPI commanding via RS232 using windows based PC "copmputers". It can say that it is design mistake. But we need live with it. (there is badbad mistake in windows what meke possible to loose data, just becouse how windows and PC "computers" handle serial port data so that there is possible loose data just becouse windows is "blind" sometimes for this. This is one reason why peoples must not do any trafic via RS232 by windows PC if need high reliability. Or there need be special protocol layer for wathing and take care this issue.
I know Rigol. Rigol have also "commands" what can use trough RS232. Where is Owon commands. I have do "lot of" with Rigol and PC via RS232. But not today becouse I totally stop play game with Rigol company.
I have not yet see any SCPI or other command set for SDS scopes, not SDK, not anything how to use USB or RS232 for commanding scope.
So, I ask agen, what for is RS232 implemented today as most of computers have USB. Oh... in secure places some USB are forbidden.. maybe they want use RS232. I personally like use teminal some times for commanding machines "by hand" but I believe not this scope.
So my opinion is that it is better if VGA is standard and RS232 is option. But I do not know all markets area and some territory in world may still want RS232.
:) :)
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A quick fix for the problem of the SDS model scope sliding around the desktop:
OWON SDS Quick Fix for Feet (https://www.youtube.com/watch?v=3oM_KZOKjSc#)
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Yes, now after marmad say, it is stated in User manual.
"Communication port: USB2.0, USB for file storage, VGA port or RS-232"
Now it is more clear if it is stated in product promotion/catalog as
Communication port: USB2.0, USB for file storage, VGA port (factory optional) or RS-232 (factory default)
or something like this.
Of course reseller need tell/show to customers what version he is selling.
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Yes, you did not buy from factory, you buy from reseller who have select this model from factory.
No, I don't think that's correct. I think Owon has changed their policy. The reseller I bought it from has been in contact with Owon about these models since middle of May. Here are some excerpts from their communication with Owon (roughly translated to English):
"19 May 2011: Bad news! Just now the entire stock of Owon PDS7102T was bought by another company, and as they had already indicated, OP = OP. Our expectation was that they would not go so fast... So the PDS7102T is already sold out, a shame, because this was the most popular model in this action. In consultation with Owon, the SDS7102, brand new (faster, more memory, LAN/USB2.0/VGA), has been added for an additional cost of only € 35."
"24 May 2011: Today I learned from Owon that the SDS7102 has no LAN port. Furthermore, they did not expect that we would suddenly want around 40; they can produce 20 in early June, but it is not known when the rest will be ready. I am awaiting the response of the production department."
So, in these communiques from Owon, VGA does NOT sound optional. If what you say is true now, then maybe Owon have changed their policy since then to make/save some extra money (which would explain all of the data floating around the Internet which does NOT list it as an option).
Here is original promotional brochure for SDS line:
http://www.eleshop.nl/downloads/Owon/SDS.pdf (http://www.eleshop.nl/downloads/Owon/SDS.pdf)
This is from an early spec sheet for SDS6062, where it lists USB or RS-232 as the communication port:
"Communication port: USB2.0 or RS-232,USB flash disk storage"
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BTW, one specification of some interest I just noticed (if you believe their specifications), which could be an indicator of non-(or less)interleaving:
The time delay between channels on Rigol and Hantek is listed at 500ps - on the Owon, it's listed as 150ps.
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So, in these communiques from Owon, VGA does NOT sound optional. If what you say is true now, then maybe Owon have changed their policy since then to make/save some extra money (which would explain all of the data floating around the Internet which does NOT list it as an option).
Yes, this is fully possible. Also I have think just with this case that it may be reason. Also it is very common thhat chinese specs and promotions material are littlebit inaccurate. Partially also becouse chinese translation to western languages is littlebit difficult or impossible. Flowers under foot give heartfull frequency ocean and mature oranges and so on.
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Flowers under foot give heartfull frequency ocean and mature oranges and so on.
I want to know what 'flowers under foot' means! ;D
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Flowers under foot give heartfull frequency ocean and mature oranges and so on.
I want to know what 'flowers under foot' means! ;D
Go to chinese forums or other chinese langiuage places, sides. take chinese text and use google translator. You have lot of fun.
But if you translate example from english to chinese, do NOT send it to chinese language peoples. Becouse you do not know how it affects. haha. I know how danger it may be - or lucky. (I'm married in China and now I feel that I'm marry not only with people but also with state - I know something)
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Ok, can someone (tinhead, rfloop, etc) give me an explanation for how wfrms/s is exactly calculated?
I have seen the figures for Rigol, Hantek, new Agilent series, etc, but I'm trying to get my head around the math. For example, if the Hantek does 2500 wfrms/s - does that mean it can actually move 5GB (1M x 2500 x 2) of data into sample memory per second? That seems highly unlikely... so is that wfrms/s figure based on a sample depth of 4k, 16k, or 40k - which seems more plausible.
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This Rohde&Schwarz paper is very good also.
Reading this give lot of understandig what is going on with wfms/s and scope blind time. Some times highes wfms is not best sometimes it is.
www2.rohde-schwarz.com/file/1ER02_1e.pdf (http://www2.rohde-schwarz.com/file/1ER02_1e.pdf)
Also Fig 9, 10 and table 3 need sometimes thinking. Sometimes need extremely low blind time %
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My question (earlier) for wfms/s was made becouse I find that Owon have trig out (rare in this price class)
Then I think if it can use somehow just like this (if have equipments for this):
R&S:
Measurement of the blind time of my oscilloscope
There are various ways to evaluate the actual waveform acquisition rate, and the
corresponding blind time of a digital oscilloscope. Since the waveform acquisition rate
can vary with instrument setup, the evaluation must be performed for the current
measurement conditions.
Some oscilloscopes offer an acquisition counter, others have a direct acquisition rate
performance display. Another possibility is to monitor the trigger out of the
oscilloscope. Every rising edge represents a new acquisition.
Just be careful to ensure that the signal source contains available trigger events that
occur more frequently than the expected waveform acquisition rate. Otherwise, the
measurement results will not show the true oscilloscope performance.
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Before my question was made becouse I find that Owon have trig out (rare in this price class)
Then I think if it can use somehow just like this (if have equipments for this):
We talked about this earlier in the thread - but the Owon trigger out is pretty much the same frequency, from 2ns until around 1ms - so I think it's more related to screen refresh times than wfrms/s - but I'm re-measuring again, this time with pull-up resistor to 5v into frequency counter.
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@tinhead,
Thanks for the data from Agilent. Very interesting.
BUT (I don't really know one way or the other) I think your Hantek figures are how many waveforms over 10 seconds the Hantek acquires, NOT the average. Otherwise, if you are correct, then the Hantek would be FASTER than the Agilent 3000 series at 20us, 200us, 2ms, and 20ms/div (actually, faster than every oscilloscope in that comparison) - which I find hard to believe. But the figures/10 are closer to what you would expect given the chart in the Agilent literature (and around what they show for the LeCroy WaveSurfer or Tek TDS3000 Series) - assuming, of course, that Agilent's data is accurate.
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Agilent DSOX3000 is sampling with much LARGER memeory depth, don't compare like that, when you look DSOX2000
you will see for example 4500 wfrm/s (20us/div) where DSOX3000 "only" 2000 wfrm/s - but DSOX2000 is sampling
into 5k memory and DSOX3000 into 1M i think.
According to the Agilent literature you posted, they did this for measuring the waveform update rates:
"Only one channel of the scope was turned on for these tests. Memory depth was optimized at each timebase range by selecting the minimum amount of acquisition memory that would also provide the maximum available sample rate."
Also, again, according to your figures, the Hantek is faster than ALL of the scopes in those tests at those sec/div ranges - mostly 10x faster.
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Not directed to any separate person here, but who ever is interest.
I will highly recommend to read this R&S aplication note. www2.rohde-schwarz.com/file/1ER02_1e.pdf (http://www2.rohde-schwarz.com/file/1ER02_1e.pdf)
It give really good knowledge about "how stuff work" and what is wfms/s and blind time to read this linked R&S aplication note. Starting from firts row, ending to last. Agen and agen. There is lot of "good to know" things and specially "goot to understand" think. Even if it is handling mainly high-end scopes but there are lot of basic information. Also it helps understand better how digital scopes work yesterday and today.
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As Agilent said "Memory depth was optimized at each timebase range by selecting the minimum amount of acquisition memory that would also provide the maximum available sample rate" - but this also means the lowest possible memory depth!!!, so you can't compare 50k depth to 4k depth - just calculate back depth * wfrm/s and divide by depth * wfrm/s from competitor and you will see how to read such tables.
Sorry, my friend - I think you are missing my point - look at the figures for EVERY scope in EVERY chart in that literature at, for example, 20ms:
Timebase - Agilent2000 X-Series - Tek DPO2000 Series - Tek TDS2000 Series - LeCroy WaveJet
20 ms/div ~5 ~4 ~4 ~4
Agilent 3000 X-Series - Tek DPO3000 Series - Tek TDS3000 Series - LeCroy WaveSurfer
20 ms/div ~5 ~4 ~5 ~3
Agilent 7000 Series - Tek DPO4000 Series - LeCroy WaveRunner
20 ms/div ~5 ~3 ~3
The Hantek, according to you, at 40k sample depth and 20ms/div, does 20 wfrms/s. That is a factor of 4 to 7x faster than ANY of those scopes - and I'm sorry, but that just doesn't make any sense. The chart is showing what some of the most expensive scopes can do, so I would have to assume that your figures are wrong.
Anyway, I wasn't planning to create a disturbance - I know you are a big supporter of the Hantek. I think the Hantek is a great scope for the money (even if those rates are /10) - better hardware and firmware than the Rigol - and I would own one now if I had found a good price before I heard about the new Owon.
But if we want to continue this discussion, it's perhaps better suited to the Hantek thread.
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if direct true capuring memory is 1k and sampling rate (as long as all samples are pushed to capture memory) is 1Msa/s can not go over 1000wfms/s and also it is impossible becouse blind time can not me zero. And if it is 1M and 1Msa/s maximum with zero blind time is 1wfms/s (even what ever is display t/div) This is for 100dollar scope and it is for 100k dollar scope.
This is good discussing also with Owon.
marmad, I'm sure we are technical peoples here. Not selling oriented peoles. Technical facts and tests are most important. All scopes have goods and bads. My interesting is truth about every pros and cons. Some people want mango, some people need banana, some people need mandarin. Also these are somehow related to price.
I hope soon know Owon tested values and also Hantek tested values. Sometimes help also some my friends etc find right scope for him. Some may need hantek, some may need Owon. King is customer or this friend and his need. I do not want never push some people buy test quipment what do not meet his needs. First need also priorize needs. (including price/budget) I want always people get what he need. Not what I like sell. If after this study it may be that people need soething what I have not. I tell it to him. I can teach him what he need, what I recommend.
One key for this is as much knowledge about machines details and characters. Many times anufacturers datasheets are not enough - need know machine itself. Car datasheet is dimensions, power, speed etc. Who buy car only knowing datasheet?
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if direct true capuring memory is 1k and sampling rate (as long as all samples are pushed to capture memory) is 1Msa/s can not go over 1000wfms/s and also it is impossible becouse blind time can not me zero. And if it is 1M and 1Msa/s maximum with zero blind time is 1wfms/s (even what ever is display t/div)
Yes, this is what I was trying to get at before when I mentioned the 'math' in my post above. Without special dedicated hardware (like Agilent's new ASIC), there is a theoretical limit to wfrms/s - and it's not very high.
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I re-measured trig out frequency using 100k pull-up resistor and frequency counter. The figures were more or less the same as I posted back at the top of page 7 of this thread. The frequency seems more closely related to refresh rates then to wfrms/s, but in any case, the frequency never climbs higher than about 25Hz. The duty cycle time MIGHT be an indication of 23% dead time.
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I re-measured trig out frequency using 100k pull-up resistor and frequency counter. The figures were more or less the same as I posted back at the top of page 7 of this thread. The frequency seems more closely related to refresh rates then to wfrms/s, but in any case, the frequency never climbs higher than about 25Hz. The duty cycle time MIGHT be an indication of 23% dead time.
Memory depth 1k
example 1us/div
1MHz signal to CH1 input. CH2 off.
all extra functions off, like measurements, cursosr, dots connection etc. (I mean minimize all processing what scope do blind time)
Trigger edge.
What is trig out freq?
I hope it is not so that capturing is related to display refres time. (just as -80's digitals... ) It can not be...
But it can be that trig out is not real trig out... becouse there is not clear explanation what is this trig out...
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ok let's calculate for DSOX3000, 50000 * 5 = 250.000, now Hantek 4000 * 20 = 80.000, so which one is higher?
This means DSOX3000 would do 62.5 wfrm/s when there would be an option to enable 4k, or vice versa
Hantek would do 1.6 wfrm/s when it would be able to capture 50000point at given sample rate.
I posted a response to this over in the Hantek - Tekway - DSO hack thread - where it makes more sense.
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This scope is probably the one I'm going to get for college mostly because its portable its cheap and the screen is nice. My question is is anyone aware if owon will updated the software because the current software in his reviews are a possible deal breaker?
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Just received my SDS8102. There will be a lot of things to check.....
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This scope is probably the one I'm going to get for college mostly because its portable its cheap and the screen is nice. My question is is anyone aware if owon will updated the software because the current software in his reviews are a possible deal breaker?
Xiamen Lilliput overseas sales department have promise (to me after I ask) that this FW is not "final" version. They know it need some development and bugfixes.
They "promise" that new FW come later. FW do NOT come (afaik) as public downloadable. Main stream looks that they give it directly to distributors and customers. Now there is not ready FW update. They can not answer exactly timetable. But I somehow understand that "soon". (what is soon? 3 weeks? 3 months? I do not know - yet)
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I will make some tests soon with SDS7102 w option VGA
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Cool as long as there's updates for the scope coming I feel comfortable spending my money.
ps excited to see the teardown
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Still tabulating some tests and trying to work out the results... I'll post the third (and final) installment of the SDS7102 review sometime in the coming week. Bear with me ;)
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Is there going to be a treadown because I,m interested in the quality of the construction?
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Is there going to be a treadown because I,m interested in the quality of the construction?
I Don't think so . I asked the same question earlier in the thread a the reply was he is still in the 'Golden warranty period' ie he's not going to ( publicly ) void his warranty. (Bet he has a sneaky peek though ;D)
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maybe soon (inside two weeks) I have something to tell. There is coming some lot of these and I will take one for my deeper tests. This I can not promise what results and examinations are public and what not. But some "opinions" I can promise later.
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Is there going to be a treadown because I,m interested in the quality of the construction?
I can't exactly promise a teardown at this point, but I'll have a lot of extra info - some of it pertaining to what you're interested in - in a couple of days.
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Only overall look after arrive.
DSO7102 (Vga)
V 2.1.1
First feel is: nice, not feel like cheap plastic, finishing good. (if I give points about look and touch feel: Hantek get 6, Rigol 7, and this 8). In hand it feels more expensive than it is. And this display...
Good TFT. Also if dim baclight. Owerall feels well made.
separate on/off's for mains and scope on/off (becouse battery option)
Fan is - just extremely silent.
This machine looks and feels well made (outside).
Now I only have time to fast look freq response. This I do later better. Now need study littlebit menu and features.
I have seen many kinds of scopes, old professionals and high-ends and some these entry level scopes.
This is better than I expect. (this is only first feel)
Freq response - It is good! Really good. Nice gaussian reasponse without highs and lows. Well made.
Noise looks reasonable and ok in this class. I have not tested more deep but fast mutual feel was.. this is of course better than Rigol ( and also maybe better than Hantek. maybe specially some class of noise is lower)
Compared to 500kHz pure sinewave signal as reference. (300mV p-p)
Scope 50mV/div, 2ns/div
-3dB frequency 135MHz, -6dB 230MHz also I only fast turn Signal gen f up to look simply where it loose trig... after 380MHz without any trying to find trig by any settings. Signal level same, only scope changed to 20mV/div))
Signal termination in scope end with Tektronix 50ohm terminator. Generator well leveled HP8657B.
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Freq response - It is good!
-3dB frequency 135MHz, -6dB 230MHz
and how it is compared to rigol ds1052e hacked to 1102e?
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This machine looks and feels well made (outside).
I have seen many kinds of scopes, old professionals and high-ends and some these entry level scopes.
This is better than I expect. (this is only first feel)
Freq response - It is good!
Yes, it's true.... and all of this I've mentioned in the videos and the pages of this thread. Everything that Owon claims in their specs (except, of course, for optically-isolated synchronous Trigger out) appears to be correct. But the problems lay elsewhere - in the unreported stats.
But now you can compare the Hantek with the Owon in this regard - quite simple to test them against each other, as Dave did with the Agilent and Rigol.
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Only shortly and not exactly compared. So this is mutual but I know something and it as "wise quess".
Hantek have goods and bads also. But Hantek is littlebit like DPO. It can capture more wfms/s to display.
Owon is bsic sequantially capture-display-capture-displ. conventional DSO. But in this it is very good in this price class imho.
Later more, some days now extremely bysy.
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hmm.... my SDS8102 arrived in a version : V1.0.1. May be i need to check for updates from Owon. See if there is any update.
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DSO7102 (Vga)
V 2.1.1
good point, marmad what's is on your Owon ?
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V 2.1.1
Same. I did hear on samenkopen.nl about a bug with Chinese characters appearing when you use FFT - that was on units shipped in late June (early July). But 2.1.1. doesn't do that - so I'm guessing that might be the 0.0.1 in 2.1.1 ;)
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Shortly about FFT:
First opinion without enough testing, only just as "hello" test: normal FFT what I have seen this price class DSO.
Can not window with waveform. Seems like they have put more development for dB scale than Vrms scale.
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hmm.... my SDS8102 arrived in a version : V1.0.1. May be i need to check for updates from Owon. See if there is any update.
There is not public loadable FW updates.
If you buy from distributor (official what have deal with Owon, ask them) If directly from China or some "unknown" ask Owon with polite letter including your scope serial number and FW version what you have. service at owon dot com dot cn
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hmm.... my SDS8102 arrived in a version : V1.0.1. May be i need to check for updates from Owon. See if there is any update.
You have SDS8102 - they haven't been manufactured for as long as SDS7102 - different model. Plus you just got it shipped directly from Owon a week ago; I'm sure there is no later firmware for SDS8102.
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There is not public loadable FW updates.
That's a scary thought... Maybe OWON uses some sort of JTAG pins on the mainboard to update rather than USB?...
So you'll have to send the scope back to OWON or a Distributor?
Do you think they'll charge for the update? The total cost would then be $Shipping+$Labour.
Sounds like the scope is getting more and more expensive.
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No, afaik, update is by USB. Becouse end user can do it. Owon can send it to customer. Many end users have also buy directly from Owon. (also distributor is customer ;) )
But they really do not always new FW hurry and hurry... you look Hantek. Just after FW update new update and some updates very loose done and new bugs and old bugs... most I like personally product what do not need always update after update. There need be wise developers who collect all repair and development needs and then carefully do it.
Owon FW looks like quite clean from bugs (but also littlebit less features and extra dingle dongles than Hantek) if compare Hantek where today is bug behind every corner - also with important things. (example capture meory selection bugs what is realy terrible). FW is neraly like mixed spaghetti after these "programmers" who do all just now and quickly before lounge and just as try-fail-try method. Pawns can write Feynman book if they try enough time.
Some small Hantek exaples. Last time there was bug(s)... scope crash down if select XY mode after normal default state. (one channel active when push XY) Now they have repair it. Oh, search help text... crash. Well... select exaple 500k mem. Oh... not 500... it is 400 but oh... it is sometimes not...it is 320?... oh now you turn scope more fast. Without warning it select 4k. (but still it show 512k.) etc etc. How about display scaling... try cursors... change speed (stop mode) oh... nice but wrong numbers. Lot, really lot of things and some times feel that more and more after every update? Littlebit less total crashes. Total crash to mad random is now less. FFT, still showing samplerate wrong. Still zooming and cursors positions calculated wrong.
Stop and change speed... oh where disappear your multi waveforms "fast" captured display... where they go... oh some measurement you can do only if scope run.. really clever. But wow, you can change skin color to lime or pink... this is veery important. Later you get user manual as movie. Maybe also tetris.
Then peoples learn to first ask, how I can get new FW, every week, every day...once in year... like some important value. maybe tomorrow manufacturer specs are... 1G fast memory, 12" superdisplay... watch also video (Hantek) ... Voltage accuracy 0,1%, FW updates >6 per year(guaranteed minimum). etc...
I want ready made... never FW udate. I remember HP and -80's ... scopes are nearly ready before they come available, If there was one bug it was as big big shame ... nearly as full face loose. Today... peoples ask how often can get new FW. Just as what rise time or do it have battery... do it have frequently updated FW. I think this all is becouse B.Gates have born.
;) ;) partially joke...
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No, afaik, update is by USB. Becouse end user can do it. Owon can send it to customer. Many end users have also buy directly from Owon. (also distributor is customer )
But they really do not always new FW hurry and hurry... you look Hantek. Just after FW update new update and some updates very loose done and new bugs and old bugs... most I like personally product what do not need always update after update. There need be wise developers who collect all repair and development needs and then carefully do it.
Owon FW is very clean from bugs (but also littlebit less features and extra dingle dongles) if compare Hantek where today is bug behind every corner. FW is neraly like mixed spaghetti after these "programmers" who do all just now and quickly and just as try-fail-try method. Pawns can write Feynman book if they try enough time.
haha, True.
My stance on the whole "update too often" thing is that I feel comfortable knowing that I can rely on a company continually updating the FW and correct bugs. It can be a pain however if you just buy a scope and there's been 10 updates out for it, and you have to update each one. I haven't looked at Hanteks update process, but they should make it so that you can update to the latest FW which includes all previous fixes... Maybe they do that already? They also cant support the product "forever", if they leave it and there are a lot of bugs around every corner, that could be bad for business. It looks like the newer Hantek models will be using the same/similar FW though, so I guess we can count on them supporting it for a while.
I'd take less dingle dongles for better FW. The one thing I just don't know about is the lack of a fine control... Maybe it's just me, but I liked my fine control, I would think its useful in some situations...
If OWON is going to be releasing updates, It would be far less expensive for them to set up a server and allow people to download from the website or setup an email server and email it to registered owners. This would limit (wo)man hours, and shipping costs (if they sent it by mail).
But your definitely right about the try-fail-try method. By that logic it'll be 10 years before anyone sees an update! ;D
I think this all is becouse B.Gates have born.
He's not entirely to blame, he just introduced the possibility to make products that work only sometimes, the rest was up to the manufacturers following his theory.
I coined it "Bill Gates Theory of Bugged Crapware".
Anybody else notice before microsoft came out that software for devices worked?
Still looking forward to your last video marmad. I'm sure there is a lot of setup and planning on the last one though, so take your time.
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"haven't looked at Hanteks update process, but they should make it so that you can update to the latest FW which includes all previous fixes... Maybe they do that already?"
Thank Hu they have done this.
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I try find info where was information that TFT have CCFL baclight. I did not find (maybe bad search or I remember wrong)
SDS7102 have Innolux AT080TN52 V.1
LED backlighted TFT
And this is really good news! (Manufacturer well known Innolux, LED backlight)
"Quick info":
1 LCD size 8.0 inch(Diagonal)
2 Driver element a-Si TFT active matrix
3 Resolution 800 × 3(RGB) × 600
4 Display mode Normally White, Transmissive
5 Dot pitch 0.0675(W) × 0.2025(H) mm
6 Active area 162.0(W) × 121.5(H) mm
7 Module size 183.0(W) × 141.0(H) × 6.3(D) mm Note 1
8 Surface treatment Anti-Glare
9 Color arrangement RGB-stripe
10 Interface Digital
11 Backlight power consumption 1.782W (Typ.)
12 Panel power consumption 0.356W (Typ.)
13 Weight 258g (Typ.)
(if you have seen bad highly glossy terrible displays in some pictures there is glossy protection plastic what can take off just after buy)
Connector for backlight:
1 VLED+ P Power for LED backlight anode Pink
2 VLED- P Power for LED backlight cathode White
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LED backlighted TFT
And this is really good news! (Manufacturer well known Innolux, LED backlight)
Hmm... I think this is a non-issue. There are good and bad points behind both CCFL and LED. The main advantages usually mentioned with LED backlights is the fact that their brightness doesn't change over time - and that they last longer than CCFL backlights - but these are both fallacies.
From a Hitachi application note on LED backlighting:
"Attrition in LEDs is cause by the current flowing through an LED junction and non-uniform current flow, resulting in small temperature differentials within the chip. These temperature differentials exert stress on the lattice structure which makes up the LED, causing minute cracks to occur. These lattice defects accumulate with use, and reduce the photon conversion efficiency of the chip, so reducing light output."
And:
"The white and blue LEDs used in backlights suffer from higher attrition rates, due to their relatively high forward current required. Hence the lifetime of these LEDs are subsequently reduced, typically LEDs can be expected to last in excess of 100000, however this is only true for red and green LEDs. However LCDs most commonly use backlights which produce white light, these backlights can be expected to last around up to 50000 hours, typically lasting between 10000-30000 hours with normal use, this compares to 50000 hours typically lifetime of a CCFL."
The data sheet for this display lists the LED life time as 20,000 - with the following note: 'The “LED life time” is defined as the module brightness decrease to 50% original brightness at Ta=25? and IL =180mA.' This is less than 1/2 the lifetime of a typical CCFL.
I have a 10-year old CCFL-backlit monitor running beside me - yes, it is dimmer than 10 years ago - but it is still working and totally usable.
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Yes, but correct information is: Owon have Led backlighted TFT, not CCFL.
Some like apple, some like orange. I like that LED (bad or good) is today and CCFL's are history.
(I have repaired Agilent stuffs with CCFL's dead. Also inverters dead. )
in specs 20000 is minimum. Not typical. And 50%. 50% is not much of. Just like camera one stop of aperture.
If you have look in real life how much is one f stop with eyes?
But so or so. It is LED. No need more think what it is.
How is R&S or Agilent?
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Yes, but correct information is: Owon have Led backlighted TFT, not CCFL.
I wasn't questioning that information. I was questioning this: "And this is really good news!"
in specs 20000 is minimum. Not typical. And 50%. 50% is not much of.
1) The lifetime of backlights (CCFL or LED) is ALWAYS listed in specs as 50% of brightness - so the minimum lifetime of the LED backlight in this display is STILL 1/2 that of minimum lifetime of typical CCFL.
2) The 'minimum' is also ALWAYS given in specs. The fact that they DON'T list a 'typical' is actually not a good thing.
3) 50% is exactly what it is. You can see the effect on the Owon by just turning the backlight down to 50% in the display settings.
To me, the only advantage of an LED backlight is no inverter (perhaps better colors - but this is debatable). But for that, you often have to trade brightness and shorter lifetime.
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Yes, it is good news.
Leds are in many places listed as 70% but also 50% is very common.
battery life in Owon.
battery is 8000mAh nominal.
datsheet aboit dislpay.
LED voltage min 9,3: typ 9.9; max 10.5V
current 162: 180: 198
In thi solution it is used
100% 9V, (this is lower) More slowly decay. compared to CCFL, LED only decay byt typically do not wear out like CCFL
80% 8.7V
50% 8.2V good setup value for normal use 50 - 80%) Agen more lifetime
30% 7.9V
0% 7.35V (still can use in dim room.)
Owon tell that typical battery time is 4h. It means around 2A current. Well, display baclight take 150mA. If you change it CCFL what is total including driver circuits. Everyone understand that in this solution LED baclight is really like "anything" to do with battery live.
So what is problem.
Only more reliability. ;) Maybe it is problem becouse if product lasting more than warranty time it is bad business.
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Yes, it is good news.
Seriously? You're going to keep this debate about the 'good news' going? ;D
compared to CCFL, LED only decay byt typically do not wear out like CCFL
Where do you get this information? Please provide reliable source, as I did with the Hitachi note. There is a LOT of misinformation about LED backlights around (many people believe they don't lose any brightness over their lifetime).
50% 8.2V good setup value for normal use 50 - 80%
This is nonsense (or personal opinion). I have the Owon in front of me - 50% is VERY dim - 80% is minimum I would want to use it in daylight (less, of course, is possible when in a darkened space). The backlight is NOT very bright. Do I have to remind you that you wrote just a few posts back:
Quote from: rf-loop on August 22, 2011, 07:44:31 AM
Good TFT. Also if dim baclight.
This was completely accurate: it's a good TFT but it has a dim backlight. You should read your own posts ;)
0% 7.35V (still can use in dim room.)
Then you have MUCH lower standards than me in terms of display brightness.
Only more reliability.
How so? Again, according to the manufacturer's specs, the LED backlight in this particular LCD screen has HALF the lifetime of a typical CCFL backlight - this is based on data.
I get it - you like LED backlighting - I prefer it as well, all things being equal - but it is purely a subjective opinion because you haven't provided any hard data to support any of the claims you're making. I mean, you could argue that not having an inverter in a noise-sensitive device is a good thing - but your other points: brightness and reliability are unsubstantiated. I'm fine that it uses an LED backlight - but if you said to me, I can have a brighter screen if it uses CCFL (without adding extra noise to the device), then I would take the CCFL.
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0% 7.35V (still can use in dim room.)
Then you have MUCH lower standards than me in terms of display brightness.
Yes, I can see magnitude 5-6 easy with my eyes on the dark sky.
Btw... there was some misunderstooding becouse my language. as dim... dimmed..
Also, for my eyes I like more dim light lab. But then enough light just there I need.. under microscope or in the equipment this place what I'm repairing etc.
CCFL museum manufacturers proof what they want and led lightning manufactures they own.
Some like oranges, some apples.
LED backlighted Innolux TFT was good news to me and maybe also some others. There are lot of "grey" manufacturers for example cheap LED or CCFL lighted displays... but this one is not these. Also I believe reliability is better with LED. (I did not mean ccfl bulb itself reliability alone)
Who have never heard baclight inverter fails... maybe nobody.
Also some times EMI... but in this case EMI maybe do not be more worse if they use CCFL becouse scope power allready make lot of noise. (but it is not alone Owon. Imho, I like better shielding for keep enviroment EMI low)
I do not start any argumentation competition... it is really waste of time. Everyöne can find datasheets and studies. Also other than manufacturer own studies about own products. (bias, just as hitachi... just as agilent... all do it)
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Btw... there was some misunderstooding becouse my language. as dim... dimmed..
Ahh... sorry, I misunderstood.
I find the backlight a bit dim for my tastes - but I work in a 80m2 room with many huge windows along 2 walls. It seems less bright then the Rigol was, although I have no way to compare anymore. But it's definitely a nice quality LCD, nice anti-glare coating, etc, - as I highlighted in my video review.
But I have to say, I don't like Owon's choices of screen colors or font - and that they don't give you a method to control the relative brightness (or change the color) of the graticule - it's either on or off - and I feel it's too strong in comparison to the other elements on the screen. But of course, these are all things that could be fixed/added in updated firmware.
But you know, it's so odd that the display of the Owon is higher resolution then the one on the new Agilent X series (and the quality level is probably equal or better), but it looks so crappy compared side by side to the Agilent, because of bad visual design. Most of these Chinese manufacturers need to hire some GOOD visual designers - because their screen layouts, colors, fonts - sometimes even the product design itself - makes them LOOK cheap - and there's no reason it has to be that way - it's one of the easiest things to fix.
When I was a kid back in the '60s, no one took Japanese products very seriously because, even if they were well-made, they LOOKED cheap. But the Japanese learned this lesson quickly, followed later by the Koreans. Now it's China's turn.
(bias, just as hitachi... all do it)
Hitachi makes many LCDs - some with CCFL backlight - some with LED backlight - they aren't biased towards either type of backlight. The Application Note I quoted was just an assessment of the characteristics and attributes of LED backlights - and how to drive them.
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But I have to say, I don't like Owon's choices of screen colors or font - and that they don't give you a method to control the relative brightness (or change the color) of the graticule - it's either on or off - and I feel it's too strong in comparison to the other elements on the screen. But of course, these are all things that could be fixed/added in updated firmware.
But you know, it's so odd that the display of the Owon is higher resolution then the one on the new Agilent X series (and the quality level is probably equal or better), but it looks so crappy compared side by side to the Agilent, because of bad visual design. Most of these Chinese manufacturers need to hire some GOOD visual designers - because their screen layouts, colors, fonts - sometimes even the product design itself - makes them LOOK cheap - and there's no reason it has to be that way - it's one of the easiest things to fix.
When I was a kid back in the '60s, no one took Japanese products very seriously because, even if they were well-made, they LOOKED cheap. But the Japanese learned this lesson quickly, followed later by the Koreans. Now it's China's turn.
Yes. This all I can sign also.
Some words specially. Also I know this problematic. I have been there. And I'm very tightly connected to China.
But example scope... it can not do good useability if designer do not really have know-how and experience about measuring routines. There need be one "old guy" who know. But then there is also one tuth... all can not make happy. You do young hobbyists happy you loose professionals and wice versa. You can try both... many have try. I do not know any who have win this. So first they need select what side river they stand.
China flag:
1. color red --> CH1 color red
2. clor yellow -> CH2 color yelow
Reason is so simple.
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But example scope... it can not do good useability if designer do not really have know-how and experience about measuring routines. There need be one "old guy" who know. But then there is also one tuth... all can not make happy. You do young hobbyists happy you loose professionals and wice versa. You can try both... many have try. I do not know any who have win this. So first they need select what side river they stand.
This is true. But even so, once they have tried to develop a good interface, structure, menu layout, etc, they need at least one clever person with sharp visual design skills to look at it when finished and say, for example, 'No, it's not clean looking to have a san serif font printed on the front panel, but then a font with serifs on the LCD. In fact, fonts with serifs don't look very good on LCDs because the low resolution can make them look too big." ...Things like that.
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But example scope... it can not do good useability if designer do not really have know-how and experience about measuring routines. There need be one "old guy" who know. But then there is also one truth... all can not make happy. You do young hobbyists happy you loose professionals and wice versa. You can try both... many have try. I do not know any who have win this. So first they need select what side river they stand.
This is true. But even so, once they have tried to develop a good interface, structure, menu layout, etc, they need at least one clever person with sharp visual design skills to look at it when finished and say, for example, 'No, it's not clean looking to have a san serif font printed on the front panel, but then a font with serifs on the LCD. In fact, fonts with serifs don't look very good on LCDs because the low resolution can make them look too big." ...Things like that.
Yes.
But have you look chinese font. ;)
Western countries are only small part on marketing area. (this is not for UI useability and ergonomic)
I hope that font is different for other languages than china. Maybe all think this now it is not good, but then if change, well one like apple one like oraange. Some near "system" font is imho best for technical equipm, simple without small nyances is best. Mostly I have like what big traditional companies like Tek, Agilent, R$S, and lot of good others use. They use lot of thinking for this kind of questions. maybe many group meetings what style and exactly place in one knob. Also this is expensive.
There are also cultural differencies with this "taste" what is outlook style etc. (but we know that there is also some kind of common things in human "taste" eyes)
But what ever language, UI can be lot of better useability. In all parts of Tellus.
Outlook, there may be cultural differencies. (shape, colors, touch...etc)
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Just small test:
First picture.
Around 15ns pulses every 1us (pulsegenerator specified rise and fall times are 1.3ns)
Ch1 only in use. So 1Gsa/s and 2ns/div
Scope automatic measurement show 2,64ns risetime
Second picture.
same pulse CH1 and then CH2 around 100MHz sine.
Samplerate now 500Msa/s.
Trig mode ALT.
Scope automatic measurement show 3.24 ns risetime.
Signal termination is not best, only 50ohm terminator before scope input.
Trig mode "ALT" works also fine. Both channel trigs separately and trig is accurate. (CH1 and CH2 signal sources have not any kind of syncronisation between each other, totally separate sources and both individually free running.)
Pulsegnerator pulse width is not exactly 15ns. So scope do not display wrong. Only meaning in this measure was risetime.
(<=1.3ns risetime do not affect markable to this risetime result, in practice "nothing".)
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Hello everyone. First off, I'm new to this forum, so "Hello!" :D
I just wanted to post a couple of things I have learned in researching the Owon scopes.
In regard to firmware updates being released to fix the issues discussed here and I think also by 'marmad' on his youtube reviews:
I contacted Owon directly (sales@owon.com.cn) and received very quick replies from Mr Colin Lee at Owon. He stated that they consider the Owon SDS7102 to be a "mature product" and thus have no plans for releasing firmware updates. I sent links to the Youtube videos, and he apparently showed these videos to his development team. Here is a snip from our email conversation:
ME: Thank you very much for your reply [regarding authorized resellers]. I wish to ask further questions regarding the firmware of Owon units. How often do firmware updates get released for the SDS models? and how would I receive these updates? would they be sent directly from Owon via email or is there a download site to obtain these? I have read some excellent reviews regarding the SDS7102, but those people also commented that some features of the firmware need improvement, and I would expect that Owon would periodically release updates to improve their already excellent product. I just want to understand how the update process takes place.
MR LEE:
Thank you for reply.
If a product needs to add functions or need to solve a bug, the firmware needs to be updated, it is right, but before selling our products, we already shape our products in good condition, so there is not promising to updated firmware often
If a product needs update firmware often, we can regard that it is not a mature product, is it?
If our products need update, we can send software to you via email, and you could operate update by yourself.
Kindly regards,
Mr. Colin Lee
Another reply after I sent the Youtube videos:
MR LEE:
After viewing, the man gave his opinion such as how to better design menu and show data in display, and also point out the features such as big LCD display, 10M record length, VGA Port etc.
After all, we think we have not plan to add the functions the man need recently, because we regard this unit as mature products. Unlike other brand scope need to update firmware time by time.
Furthermore, I contacted a USA distributor of Owon scopes (saelig), and asked basically the same questions.
Here are some snips from that email conversation:
ME: ...how do we go about obtaining firmware updates for this scope? Will Owon release these updates to you, then we can get notified by email? From everything I have researched, the Owon is a great scope, but some of the firmware features need lots of work, so I would assume the manufacturer will be releasing updated firmware occasionally. I don't see anywhere on owon.com.cn to download firmware, and have read that Owon has a bad track record for publicly releasing firmware updates.
Al MacRobbie:
I found from OWON today that F/W upgrades are not, at least for the present, going to be made available to the general public. OWON factory-authorized service centers (like Saelig Company) are to perform upgrades as a service to our customers.
I spoke with a sales rep at Saelig. He stated that they would perform such updates free of charge, but the owner would need to pay for shipping & handling.
I have a feeling Owon is trying to prevent these scopes from being hacked like the Rigol scopes have been.
I hope this info is useful to someone.
Ryan
PS. I ordered a SDS7102, expected arrival next Tuesday, because even with the limitations discussed, it appears to provide suitable functionality for my basic needs. Not having a lot of fancy equipment, I can't do extensive tests on it, but if you have questions about the scope that can only be answered by having the physical unit, feel free to ask.
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Hi Ryan,
Thanks a lot for sharing your info. It's a shame that they aren't planning an upgrade soon, since I think the firmware needs some work still. I also had some conversations with Colin at Owon - but mine were about some problems I discovered with the scope - but, in any case, he was responsive to my questions.
I've just been putting together the third and final part of my video review of the Owon, which I hope to get posted by tomorrow - or Monday at the latest. But, before then, just let me say that, in my opinion, the Owon SDS line is a very well-built, good-looking, feature-packed (at least in hardware) scope that is definitely worth the money they ask. But, unfortunately, it's not a very powerful or fast scope in it's price range - and that, at least for me, is the problem. If you don't mind trading waveforms per second, fast screen updates, and DPO qualities for the 800x600 screen, 10Mpts, VGA out, and the battery option, it's probably the best you can do with your money.
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It is a shame that some of these manufacturers don't realize the value that can be had from releasing an open-sourced version of their hardware.
In the radio-controlled model market, one manufacturer (FlySky) has an 8-channel RC system (Atmel based) which comes with pretty crappy software -- adequate but really not using all the processor power available and delivering only minimal, partly-implemented features. A couple of guys have developed their own much better firmware for these RC sets and the result is that they now perform as well as products costing four times as six or seven times the price.
As a result, lots of people are buying the radios and reflashing them with the new code.
The benefit for the manufacturer is that they no longer have to fix the bugs (not that they were bothering to do so anyway) because those who find the software bugs a problem can simply reflash to one of the better open-sourced versions -- and the product now has a much greater appeal because its capabilities are effectively doubled.
So long as a scope company isn't deliberately ankle-tapping its hardware by way of the firmware (like the Rigol) then there's surely nothing to lose by selling it with whatever documentation is required for others to write their own open-source (or proprietary) code.
Software seems to be the Archiles heel of many Chinese manufacturer so why not avoid a whole lot of hassle and allow users to fix/rewrite the damned stuff themselves?
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Yes, captured and displayed waveforms per second is not fast. This is in this meaning as conventional capture-dislay-capture...scope. It can not display many captured waveforms more in one udated display frame.
Display update rate is maximum around 25 frames per second. (human eye can note around 10 per second (as simple thumb rule only) This scope work with this principle that one capture per one updated screen. Screen update rate go sslower if there are other functions as example persistece or some menu displayed) Andif capture is slower than maximum usable screen update time. (example if horz speed is 10ms/div it meand around maximum 5 updated capture per second and there is no any reason also update it faster on the screen.
So of course then wafeforms rate go slower if horiszontal time rise (time/div), this happend in all scopes.
But fast and fast... wfrms/s rate slow but...
You can look what is waveform rate in hantek (maximum). maybe it is ten times more. But, it can capture full speed only to 4k memory. Under half speed can go to 1M memory (max 400Msa/s and 200 for 2 channel max)). There it can capture 400us/div with 100Msa/s (ten times slower)
Faster than 400us/s you can not at all use 1M memory.
What scope name can capture in this price class 1Gs/s speed if time setting is 500us/div. There are not so many.
But example random spikes hunting it can use slow horz speed, high memory and so high samplerate and this way you can also try minimize blind time ratio. This is not of course same as can do with high wfrms/s but some cases these cind of "optimizaton" may give cheap way to solve some needs.
If really need high wfrms/s and small percent blind time it need buy real fast wfms/s RTO/DPO as Agilent or Rohde&Schswarz.
More I have look Owon - it feels better. (UI is not as good as it can do with these HW what scope have... there are unused resources lot of)
So, as Hantek, as Rigol, as Owon, etc there are many pros and cond including money. Owon most high strenght is 10Msa full speed memory. And also nice good display and really nice outside quality. It is and all these are compromize with littlebit doiffenrent weighted things in design.
Also extremely nice that fan in Owon is really silent. It is difficult to find there is fan.
Also fnishing is good. So good that someone tell that - where I can see China... "made in China"-look do not pop up to eyes.
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(Hope this isn't too off-topic... it's in reply to what RCMR said)
I absolutely agree, RCMR. So what would it involve for several EE's to get together and design an open-hardware scope? There are several projects out there which are partially open, for example DPScope (dpscope.com) (open hardware, closed source software and firmware), bitscope.com, etc... Also see http://www.opencircuits.com/Oscilloscope (http://www.opencircuits.com/Oscilloscope)
However, it seems they are all low-bandwidth and partially closed projects, as well as being PC scopes rather than standalone units.
It would be great to see a fully open scope, well designed and well documented, which could offer features of some of the higher end scopes, and also allow full customization by the end user if desired.
I would certainly be willing to contribute to such a project in any way I can (programming, UI design, electronics design, parts sourcing, etc)
Want to start a new topic to discuss this?
Ryan
It is a shame that some of these manufacturers don't realize the value that can be had from releasing an open-sourced version of their hardware.
In the radio-controlled model market, one manufacturer (FlySky) has an 8-channel RC system (Atmel based) which comes with pretty crappy software -- adequate but really not using all the processor power available and delivering only minimal, partly-implemented features. A couple of guys have developed their own much better firmware for these RC sets and the result is that they now perform as well as products costing four times as six or seven times the price.
As a result, lots of people are buying the radios and reflashing them with the new code.
The benefit for the manufacturer is that they no longer have to fix the bugs (not that they were bothering to do so anyway) because those who find the software bugs a problem can simply reflash to one of the better open-sourced versions -- and the product now has a much greater appeal because its capabilities are effectively doubled.
So long as a scope company isn't deliberately ankle-tapping its hardware by way of the firmware (like the Rigol) then there's surely nothing to lose by selling it with whatever documentation is required for others to write their own open-source (or proprietary) code.
Software seems to be the Archiles heel of many Chinese manufacturer so why not avoid a whole lot of hassle and allow users to fix/rewrite the damned stuff themselves?
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Here is SDS7102 frequency response. Not bad. Note that freq scale is linear. Yellow spikes are generated in CH1 adding pulse when freq step. (step is 10MHz, starting 1MHz ref level. -6dB point is around 250MHz.
maybe this 200MHz level is possible to rise - if <clip>. But other hand... it is maybe better to add brickwall filter after littlebit over 200MHz, it is maybe more important than mod to more high freq resp.
(http://i969.photobucket.com/albums/ae171/Xie_07/fresp_50ohm_orig.jpg)
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Although its possible, I think it won't be cost effective. It gets more difficult the more bandwidth you need; so far the highest frequency DIY DSO I've seen is this Polish school project, it has ~ 5 MHz of true bandwidth and ran to ~ $300 in parts, just $100 shy of the 60 MHz Rigol.
DIY digital 2ch oscilloscope (https://www.youtube.com/watch?v=iw0cKOEjnW8#)
See the comments by the builders.
(Hope this isn't too off-topic... it's in reply to what RCMR said)
I absolutely agree, RCMR. So what would it involve for several EE's to get together and design an open-hardware scope? There are several projects out there which are partially open, for example DPScope (dpscope.com) (open hardware, closed source software and firmware), bitscope.com, etc...
Software seems to be the Archiles heel of many Chinese manufacturer so why not avoid a whole lot of hassle and allow users to fix/rewrite the damned stuff themselves?
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so far the highest frequency DIY DSO I've seen is this Polish school project
QurDSO Spring 2011 (look on ourdev.cn) have 2 x 125MSs, 30Mhz bw and nice 480x320 screen,
however my personal fav. is this one:
http://www.mikrocontroller.net/topic/228997 (http://www.mikrocontroller.net/topic/228997)
analog part designed for 150MHz, sampling with 50MSs only, but look at the self made enclosure
and the TDS2xxx "looks-like" firmware.
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Display update rate is maximum around 25 frames per second.
Yes, that it is the absolute maximum - but it rarely goes this fast. The average is probably closer to 12-16 FPS.
human eye can note around 10 per second (as simple thumb rule only)
This is missing the point - the human eye can process 10 to 12 individual images per second - but the way we perceive speed vs. stuttering (slow, sporadic movement) is much more complex. The Owon FEELS slow and stuttering at MANY settings - like it's not capturing and displaying waveforms as fast as it should - and that, IMO, is their biggest problem.
You can look what is waveform rate in hantek (maximum). maybe it is ten times more.
Testing the Hantek now, I think it's much more than 10x at certain settings.
But, it can capture full speed only to 4k memory. Under half speed can go to 1M memory (max 400Msa/s and 200 for 2 channel max)).
Well, the Owon has similar problems. For example, at 500ns/div capturing to 1K, the speed is 16 wfrms/s - but capturing to 10M, the speed drops to 12 wfrms/s - so 25% slower.
But example random spikes hunting it can use slow horz speed, high memory and so high samplerate and this way you can also try minimize blind time ratio. This is not of course same as can do with high wfrms/s but some cases these cind of "optimizaton" may give cheap way to solve some needs.
Yes, we all know these tricks for trying to reduce blind time on slow scopes. Unfortunately, they don't help at all when hunting very short glitches - which won't be visually apparent at slower horizontal settings - and furthermore, you need to know that you're looking for them to even use these techniques. What if you're just looking at a signal not expecting any glitches? For example, when the Owon is set to 500ns/div, it's blind time is 99.98% (with 1K capture depth - even higher with more memory) - so it's very bad at seeing sporadic events (I've proven this over and over in many tests) - so you might just be looking at a signal thinking that everything looks fine (even though there are random glitches which the scope is blind to).
More I have look Owon - it feels better. (UI is not as good as it can do with these HW what scope have... there are unused resources lot of)
Now that I am testing the Hantek, I can say unequivocally that build quality and external design is better on the Owon - but the firmware is crap compared to the Hantek.
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Well, the Owon has similar problems. For example, at 500ns/div capturing to 1K, the speed is 16 wfrms/s - but capturing to 10M, the speed drops to 12 wfrms/s - so 25% slower.
1k 500ns/div ja 16wfrms/s
inside one second get 16k kaptured data and Owon use samplerate 100Msa/s
in this case ideal scope (full time active capture) give 100M
16000/100000000=0.00016
10M 500ns/div ja 12wfrms/s
inside one second get 120M kaptured data and owon use samplerate 1Gs/s
in this case ideal scope (full time active capture) give 1G
120000000/1000000000=0.12
So - what is problem with deep full speed memory. (this "question" do not need answer)
Hantek have not at all this deep full speed memory.
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Hantek have not at all this deep full speed memory.
right, unfortunately like all these other scopes with pipelined SRAM (Rigol, ATTEN, Instek, HanTekway)
only 400MSs possible, when you patch firmware to clock faster and solder faster SRAM (org. SRAM can 500MSs too,
but that's 25% overclocking, so might not work for long time) like i did then 500MSs ...
so whatever you do - still only 50% of what Owon can do.
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Wow, that Selbstbau scope is a really well done job. Very neat!
Ryan
so far the highest frequency DIY DSO I've seen is this Polish school project
QurDSO Spring 2011 (look on ourdev.cn) have 2 x 125MSs, 30Mhz bw and nice 480x320 screen,
however my personal fav. is this one:
http://www.mikrocontroller.net/topic/228997 (http://www.mikrocontroller.net/topic/228997)
analog part designed for 150MHz, sampling with 50MSs only, but look at the self made enclosure
and the TDS2xxx "looks-like" firmware.
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Hi,
I hope someone can give me a hand on this.
Compensation of the probes. I followed the instruction on P13-14 of the manual to compensate the probe at 10x, then I switched everything to 1x to check but I don't quite get the square waves I got in 10x. I tried both probes and channels. Is this normal? What results did you guys get? Is there something wrong with my Owon?
Many Thanks
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This is normal and not only Owon if scope input is AC coupled.
It depends also AC coupling low freq response how much it do this. Very slow square wave top or bottom you can nearly think as they are DC. (If square mother frequency is dropped example to 100 or 10Hz you can not see that it is square) 1kHz 50/50% square: "top and bottomm of signal you can think they are 0.5ms duration DC levels.
Normally probes what have 1:1 and 10:1 compensation is only for 10:1
In this kind of double probes 1:1 is also highly reduced frequency bandwith upper end. It reads in all specs.
You can see it if you look this rising edge with higher speeds (turn 1us/div and compare. Also 10:1 looks slow rising (becouse 1kHz output rising time is slow) but 1:1 probe looks lot of more slow. 1:1 is slow. Scope itself 1x 10x etc settings do not affect anything to freq response. Only how scope display level numbers.
But what is wrong with your scope settings. Wrong or "wrong" but:
Set CH for DC, not for AC. and probe to 10:1 (1:1 is not adjustable. Expensive probes may have inside termination box many "service" settings for calibration and freq response for freq response flatness)
use 100us/div
If need more accurate use one step lower V/div value and shift then signal so that upper (or lower) part is more than 1-2 div from top (or bottom)
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10M 500ns/div ja 12wfrms/s
inside one second get 120M kaptured data and owon use samplerate 1Gs/s
in this case ideal scope (full time active capture) give 1G
120000000/1000000000=0.12
This comparison is not valid. At the 500ns/div setting, only 1/1000 of the captured data is visible on the screen - unless you stop it, which defeats the purpose of real-time monitoring. It is NOT as useful or the same as a scope which might capture 1K @ 500ns/div @ 1200 wfrms/s - because in this case, most of the data captured would be visible on the screen, not just a tiny piece.
The 10M of memory is really only useful in single-shot mode. But unfortunately, even when using it this way, Owon has not included ANY tools for looking at these 10M records of captured data: no dual-window mode, no position indicator, no mark or search functions, and worst - no auto-scrolling mode. Have you tried to look through a single-shot 10M record scrolling with the little knob? It is TEDIOUS in the extreme, and you lose your position very quickly.
Simply adding more memory to a scope, if it's not implemented well, is not the answer to solving problems. There is a reason that more expensive scopes have less memory but faster waveform update rates.
Again, if the Owon captured 1000x (or even 100x) more waveforms per second when it used 1K of memory than when it used 10M of memory, it would be a much more useful tool.
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Have you tried to look through a single-shot 10M record scrolling with the little knob? It is TEDIOUS in the extreme, and you lose your position very quickly.
In stop mode scrolling around 10M is easy and fast. (if example 1us/div 1Gs/s 10M).
Stop > zoom out with horz speed > shift wanted position by horz pos > zoom in. Very fast can go to every place there in 10M capture. It is not good but better than nothing and same with hantek but sampling is now more slow and capture is more short.
But as before, Owon is conventional DSO with long full speed memory.
Hantek is "tiny" DPO with short memory and faster wfrms/s but really not fast. Try 20ns/div and 1M memory. You can calculate with your eyes how many waveforms/s. (be sure that you know when scope use long memory. Setting in menu do not tell always truth (it is one bug in Hantek - and there is tens of these bugs - and as talk Hantek, need know what FW becouse they are with different features and differrent bugs. (Ht. is so that some old bug go and new bugs come in every FW update. No one know exactly how they have make all this FW spaghetti.). Setting may be 1M but truth may be totally different becouse if you accidentally turn faster, scope drop 1M out and use 4k (or 3.2k depends...who knows)
After one week you find many "interesting" things. But still, Hantek is faster. Pity that this zoom is what it is. Toy zoom.
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... as a scope which might capture 1K @ 500ns/div @ 1200 wfrms/s - because in this case, most of the data captured would be visible on the screen, not just a tiny piece.
Can you name this kind of scope?
It is not Hantek DSO5000B series, this I know, but what it is?
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....no mark or search functions, and worst - no auto-scrolling mode.
Also it is nice if you can name this scope?
Hantek?
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It is not good but better than nothing...
This was exactly my point.
...same with hantek but sampling is now more slow and capture is more short.
Yes, but with the dual-window mode of the Hantek, you can at least see where you are in the waveform. As I mentioned before, it's VERY easy to lose your position on the Owon.
You can calculate with your eyes how many waveforms/s.
This is not necessarily true - from what I can tell, the Hantek wfrms/s is not linked to the refresh rate of the display - so it might refresh the display less often, but be capturing 100x more waveforms - you would have to test to be sure. But, unfortunately, it is true with the Owon - and the sad thing is that you see this effect sometimes when only using 1K of memory!
... as a scope which might capture 1K @ 500ns/div @ 1200 wfrms/s - because in this case, most of the data captured would be visible on the screen, not just a tiny piece.
Can you name this kind of scope?
It is not Hantek DSO5000B series, this I know, but what it is?
I was writing hypothetically - it's obvious that the makers of the cheap lower-end scopes are not being forthcoming with their waveforms per second specs - so you would need to test them thoroughly to find answers. But even 120 wfrms/s would decrease the blind time by a factor of 10.
....no mark or search functions, and worst - no auto-scrolling mode.
Also it is nice if you can name this scope?
Hantek?
Yes. The Hantek allows you to drop marks, jump to those marks (although it doesn't search for trigger events, etc), and auto-scroll through a waveform record. I can't believe that the Owon doesn't even do the auto-scroll, which is SO easy to implement in firmware.
I was hoping, when I bought the Owon, that it would represent a new breakthrough in price/performance at this level - and perhaps it would have if they had hired software engineers who were as clever as their product designers. I do think it represents a better level of design, build, and included hardware for cheap Chinese scopes - but it's performance is stifled by bad choices at the firmware level.
Now that the new Agilent 2-channel 70MHz is available for 2.5x more money than the Owon (but, IMO, much more than 2.5x more powerful), you have to wonder if it isn't false savings to buy one of these $500 - $600 scopes - unless, of course, you absolutely can't afford more money - or - you only do the simplest kind of work with the scope - or - you are planning to upgrade to a better scope later.
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Yes, thanks for the update and I stand corrected. those scopes are now the best I've seen for DIY. Steffen says that the actual parts cost isn't more than Euro 100, but I'm not so sure. Its interesting the discussion does suggest the cost is also ~ Euro 300 as an estimate for get it fully assembled.
Wow, that Selbstbau scope is a really well done job. Very neat!
Ryan
so far the highest frequency DIY DSO I've seen is this Polish school project
QurDSO Spring 2011 (look on ourdev.cn) have 2 x 125MSs, 30Mhz bw and nice 480x320 screen,
however my personal fav. is this one:
http://www.mikrocontroller.net/topic/228997 (http://www.mikrocontroller.net/topic/228997)
analog part designed for 150MHz, sampling with 50MSs only, but look at the self made enclosure
and the TDS2xxx "looks-like" firmware.
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Set CH for DC, not for AC. and probe to 10:1 (1:1 is not adjustable. Expensive probes may have inside termination box many "service" settings for calibration and freq response for freq response flatness)
use 100us/div
If need more accurate use one step lower V/div value and shift then signal so that upper (or lower) part is more than 1-2 div from top (or bottom)
It is fine now. Many Thanks
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Hello guys,
i've sent owon yesterday the second review video and they respond very quickly. here's a copy of what they say:
Hello,
i want to buy this oscilloscope and some of the problem in the video are annoying please fix them in the next firmware update.
https://www.youtube.com/watch?v=ZmhmZROYTbs&feature=related (https://www.youtube.com/watch?v=ZmhmZROYTbs&feature=related)
tell me if you working on it
Ido
Hello Ido,
Thank you for your message on our website of www.owon.com.cn (http://www.owon.com.cn)
After checking the video, we welcome to have good advice to our products, and will improve them in the future or take them into mind in developing new products.
But as you know, different brand of DSO has its own features and design, such as the menu design, some customers like it, others like that. And we also have our below features like video said:
8 inch big LCD
10M record length
VGA port
Battery support, etc.
If one day, we will have F/W update, we will send email to you to realize it
By the way, which country are you from?
Thanks,
Mr. Colin Lee
Xiamen Lilliput Technology Co.,Ltd
Fujian Lilliput Optoelectronics Technology Co.,Ltd
www.owon.com.cn (http://www.owon.com.cn)
Tel: 86 592 2575666 ext 1047
Fax: 86 592 2575669
Ido
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Translation:
Thank you for your email. As the video says - our product is great. If you want any changes then tuff-cheese.
Please provide more information so we can forward it to the relevant marketing people for later follow-ups.
:o
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You or someone else have never try this with Agilent or Tektronix?
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I wouldn't expect a more helpful reply for them either, but I would expect a more polished product with less to complain about, so it's not as much of an issue.
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OK I returned my Owon SDS7102... they sent the wrong model. Apparently there are two models, one with serial port and one with VGA port. I ordered a VGA-enabled model, and apparently the sales person didn't realize there are two different variations. So they (Saelig) gave me an RMA. They won't even have any of the VGA models for at least six weeks.
BTW: Really liked the scope in the few hours I had to tinker with it. However it seemed like there was a lot of noise being picked up, even without a probe connected. Tested the scope in two different locations, same thing. About 5mV p-p noise and from my limited knowledge, looked like about 200khz frequency. Seemed like a lot to me. The tech rep at Saelig turned his on, and only saw about 0.8mV noise. Maybe it has to do with my setup. I did not connect the "ground screw" but I assumed that would be handled by the grounded 3-prong AC cable? Am I wrong on that?
I could definitely see 60Hz noise with floating probes, but I guess that's normal?
Anyway, for the price, I was very pleased. Just sorry it didn't have the VGA port!
Ryan
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Translation:
Thank you for your email. As the video says - our product is great. If you want any changes then tuff-cheese.
Let me translate your translation
We don't want to invest more money in the development / bug fixing. We don't care if the product is really good or not, we just think it is good enough to make money for us. Take it as it is or leave it.
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Translation:
Thank you for your email. As the video says - our product is great. If you want any changes then tuff-cheese.
Let me translate your translation
We don't want to invest more money in the development / bug fixing. We don't care if the product is really good or not, we just think it is good enough to make money for us. Take it as it is or leave it.
What is problem with this. How you thing if you are buying car, camera, TV, Phone, washing machine, etc.
What is big difference if buy test euipment.
How many of you have send letter to car factory and ask that blinking light switch need different timing, please what time you update it. Or how is washing machine who always forget timer if you have also selected extra rinse. have you send letter to factory and ask FW update - what is answer. "Do not use this setting". How about thousands of letters arrive from peoples who do not know what is oscilloscope or and how to use it and still also they want better FW. Or some other changes.
I do not like my camera, shutter speed selection menu is bad and in wrong place, it is more easy to handle if I can go directly after I push... ok I send letter to factory. What they answer. Something that: thank your interest about our products, we allways are happy we get feedback from our customers for developing our production. (and answer come from automatized answer machine)
I have reported two small bugs in Owon FW. I have show exactly what is bug, how it works. Documented it. Sen sinfo to Owon and get very professional answer and talking. It is really so that in factory level there need be some order what to do, when to do and who do. This is not as mixewd level of hobbyist club and hobby chat box if you start talking with engineers about product designing, bugs repair etc. I well undertand that first factory need "filter" peoples answering letters. If you btal professionally and also undertand even littlebit all this complex system what is making product then you get also real answers. They have not time to play "blinking led" kidding.
One example in short time "history" was 3'rd party Linux driver developing for Owon scopes.
There factory professionals also was helping this. But as all this kind of "open" systems, they never go ready or developing stop and then nobody update anything for new models.
Last time I tell factory I have problem to read waveform binary files. Inside 48 hours and both send 2 emails... now I know.
Some small bug I have find and reported these to Owon. They promise later repair it after they now inspect and look it deeper and then add to "need to do" list.
Try send letter to Apple factory and teach them how to do. I'm iteresting what kind of answer they give. Or try same with Nikon, or maybe with Tektronix...
Main stream is that there is product. You look this product pros and cons, then you look others, also what you like or nt, also what are you feels about product. Then you select. That's it. Buy what you have inspected what is ok for you.
If you have find really bug or fail then please document it so that this simpliest first phase "filter" people do not put it to garbage and give some trivial answer. We can help factory do better or we can only make load to factory peoples who read thousands of emails. Also if you report something. Do not write as here in forum. If you want they really take you serious. make simply and clear document about what you see problem. Take good care that chinese culture and specially they language and laguage based thinking is littlebit different. Do NOT never go as wild westerns to saloon... show gun and tell that YOU are wrong, this YOU have make wrong. It is better to littlebit adapt also to cultural things. What is normal here is not always normal in China. If you can do so that chinese EE or sales person feel loose his faces... you just have loose this game. Do not show your finger to hima that YOU do wrong. You can ask that you want do cowork and help develop together better machine and it do not cost anything and also you can win more selling and more money if we do these small developments..
One problem is also that there is just one product, example SDS7102VGA.
One like orange one like apple. It is impossible to grow appleorange. I go to store and I do not buy apple if I like orange better. If I still buy apple and then go to for appeal and whimper with farmer that: I do not like this becouse it do not taste as orange, YOU have made something wrong. Clever?
If I do this... where I find one stupid. It is easy, I go and look mirror, then I find.
I have never get stupid answer from Owon after first they have understand what we are talking and why.
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All the good times.
Please choose from two things, which is better?
I want to purchase OWON SDS7102, sent an inquiry about the price of the plant, sent a reply that 100 MHz is also SDS8102, except that the Sample rate (Real time):
for SDS7102 = 1GS / s
for SDS8102 = 2GS / s
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They are all same. Really only difference is ADC sampling speed. This is my quess but there is different ADC, propably MTX2001 (quess). 7102 use MTX2002 (this is known)
But all other things are same.
If I look 2 channel use. 7102 have maximum 500Ms/s per channel.
I have measured visible rise time with one channel use and two channel use.
One channel give 2.6ns/div (averaged16) Samplerate 1Gs/s (so samples every 1ns)
Two channel give 3.2ns/div (averaged16) Samplerate 500Ms/s (so samples every 2ns)
Now if think what 8102 can give.
Maybe one channel do not rise faster becouse analog parts is limiting.
maybe two channel use give better result. maybe just like 7102 with one channel.
Also it reduce aliasing.
If need lot of 2 channel use for both 100MHz... well, think 8102. 500Ms/s is not very nice for 100MHz. (it is enough but signal do not look so nice.)
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Thank you very much.
As I understand it:
- If you often work one channel, then 7102;
- If you often work with two channels, then 8102.
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New user popping in..
I just go my new OWON and I am quite satisfied BUT found one very annoying software bug:
Scope set to 100ms/div or slower and REAL samplerate drops down to nothing.
settings:
mem set to 10M, 100ms/div.
scope shows sample rate as 10MS/s
try measuring 1kHz calibration signal, hit stop-button and "zoom in" turning timebase to 500us/div.
1kHz square wave has become total garbage, turns out sample rate is less than one-thousand of what it should be.
Can anyone check this behaviour on their own scope, is it the same in all units and firmware versions?
My scope has firmware 2.1.1
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I just go my new OWON and I am quite satisfied BUT found one very annoying software bug:
Scope set to 100ms/div or slower and REAL samplerate drops down to nothing.
It's not a bug - all DSO's set their sample rate based on the sec/div setting and the memory depth - even if they don't show the rate on the screen. At 100ms/div, a full screen of waveform data = 2 seconds of real time - how is the scope supposed to do that precisely? It has to drop the sample rate in order to have the time and memory space to capture the data.
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Thank you very much.
As I understand it:
- If you often work one channel, then 7102;
- If you often work with two channels, then 8102.
Yes but only IF you are working with 2 channels and need nearly risetime limits or need look 2 channel signal nearly or even over 100MHz. (200MHz do not look nice if samplerate is 500Ms/s)
-------------------
to mzz:
Yes FW 2.1.1 is latest.
100ms/div and you still get 10Ms/s with 0.5k$ oscilloscope? And you are disappoint or think bug...hmm
And you get same with 2 channel. 10M+10M memory.
Try same with Rigol, Atten, Hantek, Tektronix, Agilent, LeCroy.....
Btw HantekDSO5000B with 1M memory, (only possible with 1 channel), 80ms/div (becouse next is 200ms/div)
it use 500ks/s.
Simplified: 1M memory, 1Ms/s. How long time there need before memory overflow. Yes, exactly 1 second. IF this memory is whole your display and display is divided (for simple) 10 divs. Then, every div is 1/10s and it is 100ms/div.
Now, how about if your memory is 10M (and same other things) now you can capture 10Ms/s 1 second before memory overflow. If looking samplerate this Owon beats all other new <1k$ "1Gs/s" oscilloscopes what I know.
Oscilloscope XYZ is very good to read so there is not some many thinking that scope is fail or bug after you see all other things what scope can and what can not. This you find here:
http://socrates.berkeley.edu/~phylabs/bsc/Supplementary/Lab1/xyz_scopes.pdf (http://socrates.berkeley.edu/~phylabs/bsc/Supplementary/Lab1/xyz_scopes.pdf)
And what type of digital oscilloscope Owon is:
Figure 16. The serial-processing architecture of a digital storage oscilloscope (DSO).
It is not as: Figure 18. The parallel-processing architecture of a digital phospor oscilloscope (DPO).
This is perhaps more clear for read. Also some principle draws are maybe more clear, also this is Tektronix what have been clear leader in oscilloscopes 50 years but not anymore. http://ecee.colorado.edu/~mcclurel/txyzscopes.pdf (http://ecee.colorado.edu/~mcclurel/txyzscopes.pdf)
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the low end...
SDS8102 100MHz 2GS/s
SDS9302 300MHz 3GS/s
seem tempting esp SDS8102 if someone can hack to 200MHz. SDS9302 maybe pricey (cant find in ebay), if it can be hacked to 1GHz scope, that can be cool.
http://cgi.ebay.com.my/New-OWON-Digital-Storage-Oscilloscope-SDS8102-1G-s-2CH-/280714920525?pt=BI_Oscilloscopes&hash=item415be9c24d (http://cgi.ebay.com.my/New-OWON-Digital-Storage-Oscilloscope-SDS8102-1G-s-2CH-/280714920525?pt=BI_Oscilloscopes&hash=item415be9c24d)
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the low end...
SDS8102 100MHz 2GS/s
SDS9302 300MHz 3GS/s
seem tempting esp SDS8102 if someone can hack to 200MHz. SDS9302 maybe pricey (cant find in ebay), if it can be hacked to 1GHz scope, that can be cool.
http://cgi.ebay.com.my/New-OWON-Digital-Storage-Oscilloscope-SDS8102-1G-s-2CH-/280714920525?pt=BI_Oscilloscopes&hash=item415be9c24d (http://cgi.ebay.com.my/New-OWON-Digital-Storage-Oscilloscope-SDS8102-1G-s-2CH-/280714920525?pt=BI_Oscilloscopes&hash=item415be9c24d)
AFAIK SDS9302 is not yet ready (this info 2wk ago)
Mod:
Example 7102 have amazing good frequency response. -3dB point is typically over 140MHz. But it do not tell whole truth. -6dB point is far away... >>200MHz. (nearly 250MHz but this is not reliable result, it may have errors becouse matching..)
With its own probe nearly same! )
Rising -3dB point to >200MHz is maybe easy possible with HW mod in front end. BUT... it need carefully think is it wise.
Maybe better and more useful modification is reject BW! 2 channel mode it samples 500Ms/s. There leaks lot of signal over Nyquist freq to ADC. This is wrong! Also if think 1 channel mode. It is interleaved 2x500Ms/s. (Hantek is interleaved 8x 125Ms/s what is even more problematic)
it have pros and cons if think that oh... I want 100MHz scope mod to 200MHz. Well it can do but result may be more bad than good. If mod BW (-1.5 - -3dB point) to example 200MHz it need also do nearly brickwall filter after 250MHz. Without this 100 --> 200MHz mod imho it is also maybe clever think how can modify this high frequency end of BW. Front end BW is too wide... even 500MHz can leak to ADC input. It may be nice as long as you know your signal but then need no oscillocope. Oscilloscope need with unknown signal things and if there is some higher freequency components in signal it may destroy your measurements very easy. This is not so big problem with Hantek becouse its unmodified BW shape is different. It decay more fast as freq is rising after some 200MHz. Owon have more wide analog front-end and signal decay slowly. (or maybe Hantek have also but then it means that it is filtered after ADC what is possible but very danger if think that scope need "nice picture" builded from garbage.
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That's what I said.
1PCS SDS7102 Unit price @ USD400 The shipping cost from here to your country is USD75by EMS.
1PCS SDS8102 Unit price @ USD580 The shipping cost from here to your country is USD75by EMS.
Should I take SDS8102 Unit with the difference in price with SDS7102 Unit = USD180, or stay on the price / quality on SDS7102 Unit?
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New user popping in..
I just go my new OWON and I am quite satisfied BUT found one very annoying software bug:
Scope set to 100ms/div or slower and REAL samplerate drops down to nothing.
settings:
mem set to 10M, 100ms/div.
scope shows sample rate as 10MS/s
try measuring 1kHz calibration signal, hit stop-button and "zoom in" turning timebase to 500us/div.
1kHz square wave has become total garbage, turns out sample rate is less than one-thousand of what it should be.
Can anyone check this behaviour on their own scope, is it the same in all units and firmware versions?
My scope has firmware 2.1.1
Correction:
Also this correct my answer before.
I just remember chek this. (before I did not have posibility to live check)
100ms/div and 10M selected DSO7102 display 5Ms/s with 1 or 2 channel use.
Scope memory is 20div lenght (with this setting). (display is 15div)
with 5Ms/s 10M memory is full after 2 seconds. 20div 100ms/div is 2 second. This is logical.
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Should I take SDS8102 Unit with the difference in price with SDS7102 Unit = USD180, or stay on the price / quality on SDS7102 Unit?
@Alexey:
No, I wouldn't get the SDS8102 - I don't think it's worth the amount of extra money they want, unless signal fidelity in the 50MHz to 100MHz range is VERY critical to you. You don't get any added hardware features (as you do when you go from the SDS6062 to SDS7102), and the SDS7102 works well enough in that range (you can just use a single channel as needed for those speeds).
But make sure you specify you want the VGA output on the SDS7102 - it appears they've turned this into an option now - and it IS worth the extra money.
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Thanks for the advice.
Outcome: SDS7102 and VGA output - it would be a wise decision.
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Yes, buy SDS7102. I regret a bit after I got the SDS8102. I know it may be stretching the budget but the Agilent 100 Mhz 2 channels 2000 series is USD1400 or so and it does a lot more.... To me it should have been either SDS7102 or go for Agilent.
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I just go my new OWON and I am quite satisfied BUT found one very annoying software bug:
Scope set to 100ms/div or slower and REAL samplerate drops down to nothing.
It's not a bug - all DSO's set their sample rate based on the sec/div setting and the memory depth - even if they don't show the rate on the screen. At 100ms/div, a full screen of waveform data = 2 seconds of real time - how is the scope supposed to do that precisely? It has to drop the sample rate in order to have the time and memory space to capture the data.
IF 50ms/div gives me 20MS/s and 100ms/div gives me only 2 kilosamples/s I call it a BUG.
See the difference?
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just checked out exact numbers:
using 1 channel and 10M sample memory:
50ms/div scope displays sample rate as 10MS/s, time between samples 100ns ==10MS/s
100ms/div scope displays sample rate as 5MS/s, time between samples 500us(!) ==2KS/s
Anyone else see problem with that?
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IF 50ms/div gives me 20MS/s and 100ms/div gives me only 2 kilosamples/s I call it a BUG.
See the difference?
Either you aren't understanding how the scope operates - or you have a defective scope. At 50ms/div (single channel - 10M depth), the scope is sampling at 10MSa/s and capturing 1 second of data (50ms * 20 divisions). That is exactly correct: 10M / 1 second = 10MSa/s. At 100ms/div, the scope is sampling at 5MSa/s and capturing 2 seconds of data (100ms * 20 divisions), which is exactly correct: 10Meg / 2 seconds = 5MSa/s. At 5MSa/s, each byte in the 10Meg memory is equal to exactly 200ns of time (2 seconds / 10M) - which, again, is exactly correct - and the same thing that every DSO does.
Are you saying your scope does not capture down to 200ns at 100ms/div? If so, your scope is defective.
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Are you saying your scope does not capture down to 200ns at 100ms/div? If so, your scope is defective.
Exactly. My scope captures down to 500us (instead of 200ns) at 100ms/div.
So sample rate is 1/2500 of what it should be.
Now, can anyone check their scope and confirm if this is bug in firmware?
Or is it only on my scope? and/or wich firmware versions are affected?
1. Set scope to measure 1khz kalibration signal, 100ms/div and 10M sample memory.
2. Hit STOP-button.
3. switch timebase to 500us/s and it should be obvious if your scope was sampling at 2.5KS/s or 5MS/s
(4. set scope display to dots instead of vectors to check time between samples, adjust timebase to see invidual dots and determine time between samples.)
My unit works perfectly fine until i switch to 100ms/div or slower. >:(
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mzzj:
What SDS model you have?
One time you tell that scope display 10Msa/s if setting is 10M memory and 100ms/div
other time you tell that scope display 20Msa/s if setting is 10M memory and 50ms/div
I have look with 2.1.1. version SDS7102.
same settings and 100ms/div it display 5Msa/div
50ms/div it display 10Ms/div.
I have not yet looked carefully what is real samplerate becouse just now too busy.
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mzzj:
What SDS model you have?
One time you tell that scope display 10Msa/s if setting is 10M memory and 100ms/div
other time you tell that scope display 20Msa/s if setting is 10M memory and 50ms/div
I have look with 2.1.1. version SDS7102.
same settings and 100ms/div it display 5Msa/div
50ms/div it display 10Ms/div.
I have not yet looked carefully what is real samplerate becouse just now too busy.
SDS7102 like you should guess ;)
Sorry, I had wrong samplerate numbers on my first post.
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OK.
I just got e-mail confirmation from my scope importer/seller (rf-loop) that this bug affects probably all SDS7102 FW 2.1.1 versions.
(rf-loop, please correct me if you are not the person I bought my scope.)
No idea about other FW/HW revisions. Is there any other FW version out?
Hopefully it is something easy like wrong prefix with units and OWON is able to fix this
sooner or later.
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Ok.
SDS7102 display bottom of display:
(10M memory selected)
50ms/div 10MS/s
100ms/div 5MS/s
with 50ms/div scope use "normal" capturing display. (capture - display - capture - etc)
with 100ms/div scop use "scroll mode" (just as plotter with moving paper.)
50ms/s and faster, all goes right.
100ms/div ans slower. Something is wrong in FW. Looks like FW bug and IMHO bad bug. It do not use 10M memory at all in scroll mode.
If some people read this who have FW before 2.1.1 and/or Serial number below SDS71021127000
Please test this!
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OK.
I just got e-mail confirmation from my scope importer/seller (rf-loop) that this bug affects probably all SDS7102 FW 2.1.1 versions.
(rf-loop, please correct me if you are not the person I bought my scope.)
No idea about other FW/HW revisions. Is there any other FW version out?
Hopefully it is something easy like wrong prefix with units and OWON is able to fix this
sooner or later.
AFAIK you buy your scope from user "aghp" Finland
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If some people read this who have FW before 2.1.1 and/or Serial number below SDS71021127000
Please test this!
I don't have the Owon anymore - and I don't remember testing this in continuous mode. I DO remember testing in single-shot mode at slower div settings (> 500ms) - and it seemed to work fine with the entire memory.
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Hey... Been Lurking and Reading this thread over the past week... Thanks everyone for the interesting reading
(0) I just bought a new SDS7102 last week (from mortoncontrols.com here in Denver,CO)
(1) marmad: great review you did on the SDS7102 - thanks for all your effort even though you don't have it any more. Why did you get rid of it ? what did you end up with?
(2) My firmware rev: 2.1.1 Serial#SDS71021127100
(3) And yes mine is exhibiting the incorrect sample rate when doing the 100ms/div test.
duke
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If some people read this who have FW before 2.1.1 and/or Serial number below SDS71021127000
Please test this!
I don't have the Owon anymore - and I don't remember testing this in continuous mode. I DO remember testing in single-shot mode at slower div settings (> 500ms) - and it seemed to work fine with the entire memory.
THANKS!
I checked mine on single-shot mode and it works perfectly indeed.
That made me think that this behaviour might have something to do with trigger.
Next obvious thing was to check "normal" trigger --> works perfect!
This "bug" needs 100ms/div or slower timebase and "auto" trigger to be seen.
So this is not nearly as bad bug as it seemed. Maybe it is intented feature instead of bug?
Just remember to use "normal" trigger with 100ms/div and slower timebases
BIG thanks to "marmad" pointing me to dig in right direction and "aghp" who have been superb fast delivering my scope and ansvering all of my questions.
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If some people read this who have FW before 2.1.1 and/or Serial number below SDS71021127000
Please test this!
I don't have the Owon anymore - and I don't remember testing this in continuous mode. I DO remember testing in single-shot mode at slower div settings (> 500ms) - and it seemed to work fine with the entire memory.
In single shot mode, 10M memory, 100ms/dif or more slow. It capture just right speed what is display bottom of screen.
Slow speed single shot mode is not very nice to use becouse scope do not show anything when it is capturing. Then after it have captured entire memory it push captured waveform to display and stop. After it stop, signal can zoom and there is just this speed sampled data what is displayed as samplerate. 100ms/div 10M mem is now captured 5MS/s. As long as keep it stopped it can zoom in and out and samplerate is ok. But if try store single shot to USB it do not store any capture. Only picture can store. (it can push store wfrm but there is no captured data in bin file) If do store in continuous scroll mode it store only around 6kb captured data.
So it seems that continuous scroll mode and single shot also with 100ms/div and more slow have some bugs.
Together with USB store findings and these others it looks now more as just FW bug.
But in continuous scroll, something go wrong (or then it is feature but if it is feature it need clearly tell in specs and AD's.
More it looks now like FW bug after I tested also with USB trying store wfrm and reading this binary.
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in and out and samplerate is ok. But if try store single shot to USB it do not store any capture. Only picture can store. (it can push store wfrm but there is no captured data in bin file) If do store in continuous scroll mode it store only around 6kb captured data.
I remember doing this when I had the Owon - it saves the data to a USB stick fine if you have the trigger set to Normal (not Auto), as mentioned by mzzj.
But, as I pointed out in my review - it's ridiculously slow saving 10M files to the USB stick. It's much better reading them from the scope using the PC - it only takes a few seconds. The USB host (memory stick) uses USB 1.1 protocol, but the USB device (connection to PC) used USB 2.0 - so it's many many times faster.
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Is there a part 3 of the review coming?
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Is there a part 3 of the review coming?
Yes - I was just swamped with work (and a deadline) the last couple of weeks - plus I had a Hantek scope to test as well - so I couldn't find the time to edit the video that I shot together. But I think I can finally get it done today - and hopefully will have it posted by this evening.
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About some problems with slow Horizontal speed area. (100ms/div - 100s/div)
Different modeswith this Horizontal speed area have some severe problems.
This problem do not affect speed area 50ms/div - 2ns/div speeds.
--------
What I know now:
Owon have regognized problem. They are working with this problem now. After repair is tested and ready, I will inform immediatelly my customers. There is coming repair to these scopes what have this issue. Please be patient, help is coming.
Apologies about the problem what cause inconvenience to the users.
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Final part of my video review of the Owon (sorry for the delay):
Edit: See Page 1
Also, I'm posting a video review of the Hantek DSO5000B series scopes - it will be in a new thread a little later today.
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small error at 6:13 "and then i used pass/fail function of the Hantek" :)
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Around 16 captures per second is not so bad.
Absolute maximum is 50 captures per second with your settings 10M memory and 500Ms/s if there is one ideal theoretical zero dead time oscolloscope. This limit can not break with Agilent or R&S RTO.
Also trig out. It is sychronous trig out. But becouse it have fixed delay (this is not nice) it can not use with high speeds.
I have looked it with lower speeds with other scope. So that other scope look same signal what is going to Owon input. Other channel of other scope look Trig output. It is (rising edge) sychronous to trigger event but delayed. And becouse this and DSO architechture it is (also) related to wfrms/s speed. (of course). It is sychronous to captured signal trig point just this time when trig happends + delay time. But if it can use to some purpose it must be only with very slow signals. Maybe in single shot ot normal mode it can use just as indicator that there have happend event what have trigged scope. Ringing bell and you can walk near scope to look captured waveform.
Trig output is specified 5V level out, loadable maximum 1mA. Some datasheets and manual is wrong and it is not optically isolated floating output. After BNC, if need, it is extremely easy to do with just one component. (OptoMOS)
Before I think that there is not any useful aplication for this trig out:
But yes, I have find trig out is useful. It can ring bell after something special happend what I have set with trigger settings (sometimes these things need wait long time.. After time this have happend and I get info and can go to look lab room after I have finished my coffee and find what happend before and after this trig event. ;)
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small error at 6:13 "and then i used pass/fail function of the Hantek" :)
Oops... :P
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Also trig out. It is sychronous trig out.
That's true - I was a bit tired when I taped that part and didn't describe the problem very well. It IS synchronous - but it doesn't work like the normal Trigger Out works on other scopes - and how I expected it to work. If the Trigger In is faster than the timebase setting, the Trigger Out frequency should be equal to the timebase setting (e.g. 1us/div * 20).
But becouse it have fixed delay (this is not nice) it can not use with high speeds.
Well, that's a bit of an understatement - unless you consider >25Hz as high speed.
But yes, I have find trig out is useful. It can ring bell after something special happend what I have set with trigger settings (sometimes these things need wait long time.. After time this have happend and I get info and can go to look lab room after I have finished my coffee and find what happend before and after this trig event. ;)
As I mentioned in the review, it IS usable in some circumstances. But what you describe could also possibly be done with pass/fail - and using the buzzer. That's what I used when glitch hunting with the Owon.
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Couple of questions.
It is good review but you didn't compare it wit Rigol as you
said you would in the beginning. :'(
What good features Rigol have and Owon desn't? I don't
like Owon's FFT window. Does this Owon have zoomable FFT?
Can Rigol show signals over 135MHz?
Is it worth to give 130 euro more for Owon (€388,00 + free shipping)?
I find ATTEN ADS1102CML at xxxxx :) for same money as Owon.
Oscilloscope Atten ADS1102CML (https://www.youtube.com/watch?v=hrNzh72kX0E#ws)
What to buy? I wish there is 100MHz, 1GS/s, 1MS deep DSO with
good FFT for €350 but...
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What to buy? I wish there is 100MHz, 1GS/s, 1MS deep DSO with
good FFT for €350 but...
... but well http://cgi.ebay.es/270815430626 (http://cgi.ebay.es/270815430626) a Hantek DSO5102B approx. 345,42 Euro + 46,36 Euro shipping = 391,78, excl. taxes, excl. fees. There are a few more such offerings on ebay, several ending up at approx 390 Euro, incl. shipping, excl. taxes, excl. fees.
I didn't closely follow the Hantek DSO5102B price, but I have the feeling the price went down recently, maybe in preparation for the introduction of the BM (or was it BV?) models.
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What good features Rigol have and Owon desn't? I don't
like Owon's FFT window. Does this Owon have zoomable FFT?
What to buy? I wish there is 100MHz, 1GS/s, 1MS deep DSO with
good FFT for €350 but...
Prices are related also to customer care what you can get from seller. Warranty issues handling and other after sales customer care.
I know one place where you can buy fully tested Owons (in europe, so that every individual units are fully QC and tested with "burn in". You can buy with full after sales customer care price (including 1'st year warranty repair service) or without and then price is different.
Owon basic FFT window is 1x. Multiplies (zoom) is 2x, 5x and 10x. Other than 1x they are full screen wide.
1x window is 10div wide what is nice or not - I like it better than move zero to left and scale it to full screen so that agen there is some nice frequency steps per div.
I have never seen good FFT <2-3kEur oscilloscope. I have seen reasonable good FFT in one Agilent originally expensive digital oscilloscope from -90's. It was nearly as cheap real spectrum analyzers.
Also Owon FFT is not very bad. But there is FW bug in zoom so that cursors f are wrong. Owon is doing FW up for also this (under work now afaik just as also scroll speed memory and capture issue).
Owon FFT have acceptable accuracy with level differencies in FFT specially in dB mode. Absolute levels accuracy is very poor as all these cheap scopes FFT. Owon sampling quality is far over Rigol, Hantek etc. So it makes also sense in FFT dynamics.
Owon FW can be better in FFT. Cleraly they have not put so much for FFT feature. If you read different opinions it is also good to think how seriously you listen. Real skills and experience for use test equipnments in real life and not only internet is different and it can not always see easy. Imho Hantek FFT is better.
In this scope class do not think that if AD tell 1Gs/s and 1M memory that it means that you can capture 1M with 1Gs/s.
Scope have both as maximums but not same time. (in most cases)
Afaik Owon is only what have whole memory full speed and memory is also not shared with channels.
Example Hantek have "1M" memory and it is splitted 2x "512k" (these 1M and 512 are not exactly right values) if two channel use and it is not used at all with higher end of speeds.
Owon is only one what have max 2 x 10M full speed memory But if you really want use only 1M you just simple select 1M for use.. High speed and 10M amount means lot of more samplerate in lower t/div speeds. Low samplerate is also related to alias problems. I have worked in real work long time and where I hit my head mostly... with older or cheap oscilloscopes. Too low samplerate! Yes nearly all scopes have 1Gs/s with fast t/div but who need always only fastest horizontal speeds. Take 1ms period and 10ns wide pulses. You want measure pulses period and also some opinion that all pulses shape looks ok.
It is sad that there are not ANY rewievs with true lab testing with signals so that make real measurements and get real lab data and not only opinions with what ever matcbox made signals where nobody do not know anything real. No reference machines for test signals, no mesurements with enough reliable known signals. Where is data? Where are real measurements with reliable data?
But yesterday I get something to my hand:
Tested Owon SDS7102 VGA, Serial: SDS71021137xxx
V.2.1.1
1MHz +0dB Owon display 302mV 6div (used as 0dB reference level)
10 +0.06
20 +0.11
30 +0.17
40 +0.28
50 +0.28
60 +0.06
70 -0.17
80 -0.53
90 -0.85
100 -1.17
110 -1.64
120 -2.21
130 -2.52
140 -2.99
145 -2.99
150 -3.16
160 -3.49
170 -3.84
180 -4.21
190 -4.40
200 -4.50
210 -4.40
220 -4.40
230 -4.79
240 -5.20
250 -5.63
260 -5.63
270 -5.85
280 -6.08
290 -6.80
300 -7.59
320 -9.09
350 -11.76
400 -18.00
These are calculated dB values from Owon sisplayed Vp-p values.
There was used 60% level from Owon full Y scale. (6div)
Used with single channel.
Signal source HP8644B. Measured flatness is inside +-0.20dB window in this frequency area and measure error +-0.05dB.
Absolute level error is more but it have not meaning in this test. Exact correlation table for all measured frequencies is not included. These dB values need read as +-0.25dB for reasonable reliability. (+ opinon about 50ohm mismatcing over freq area but also this is not so meaningfull becouse most time peoples use this kind of bad matching in real life)
Termination is made with Tektronix 50ohm through in terminator (not high-end calibration quality) And between HP and Owon around 1m RG223 cable.
Also scope input was measured with HP 8753C network analyzer and input looks very good. Measured 0.3 - 200MHz. Owon specs tell that 15pF +-5pF. In this device it was around 7.5 - 11pF (measuring system was calibtated to used cable BNC end.)
Looked also that probes with scope are just possible to compensate with 1kHz square to flat becouse probes compensation pF range limit. (this scope input capacitance is so low that probes adjust range low end was just near. If Owon use these probes and input capacitance is as low as measured there is posibility that some individual probe can not compensate if adjust limits vary.)
My measurement with around 70-75ps (yes picosecond) risetime specified pulsegenerator. (Tektronix 284)
Around 2.0ns. This was made with Fujikura RG55 80cm cable and poor type BNC and one pipe termination to 50ohm (50 oh terminator is not high grade... but littlebit better than LAN quality what normally are poorest)
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It is good review but you didn't compare it wit Rigol as you
said you would in the beginning. :'(
Well, a couple of points:
I haven't had the Rigol in my hands for a month and a half now (not at all when I had the Owon) - and I didn't have a definite plan to review other scopes when I sent it back. So what little comparison I could do was based on my memory of using the Rigol - or on checking back in the manual.
Secondly, to be perfectly fair, the scopes are not really exactly comparable - since the Owon (and Hantek as well) have much bigger screens then the Rigol - and we know how that affects the price of scopes - not only in the obvious expense of a bigger LCD - but in the added costs to capture and move the extra data (pixels) to it. They just happen to be the only DSOs I've had my hands on in the last 2 months.
What good features Rigol have and Owon desn't?
Much of this you can determine by simply downloading the manuals and looking through them. IMHO, as a programmer, the only thing the Rigol has that is sorely lacking on the Owon (as well as the Hantek) is the SCPI implementation and VISA driver - this should be a standard feature on EVERY piece of test equipment.
I don't like Owon's FFT window. Does this Owon have zoomable FFT?
I think rfloop just answered this in-depth.
Can Rigol show signals over 135MHz?
This is info you can certainly find elsewhere in this forum (or by asking in a new thread).
Is it worth to give 130 euro more for Owon (€388,00 + free shipping)?
As mentioned above, you're basically paying for extra hardware in the Owon: 8" 800x600 LCD (vs 5.7" 320X240 on the Rigol); 10Megs of memory per channel; VGA output; battery compartment and capability; and a silent fan. If none of that extra hardware means much to you, than save your money and get the Rigol.
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As mentioned above, you're basically paying for extra hardware in the Owon: 8" 800x600 LCD (vs 5.7" 320X240 on the Rigol); 10Megs of memory per channel; VGA output; battery compartment and capability; and a silent fan. If none of that extra hardware means much to you, than save your money and get the Rigol.
Owon have 10Mpoints memory with full 1GSa/s if single channel use.
With two channel use 2x 10M with maximum speed what is 500MSa/s per channel with not interleaved sampling. There is 2 pcs 500MHz ADC in single chip.
Rigol have 16kpoints memory with full 1GSa/s
Hantek have 4k full speed memory and math and averaging possible only with 4k.
Rigol have 8+8k if two channel use and then maximum 500MSa/s. Also Owon have max 500MSa/s with two channel but then it is with 10+10Mpoints with 500MSa/s
Rigol have one channel maximum 1Mpoints and 500MSa/s but two channel maximum 250MSa/s to 500k + 500k memory.
Hantek maximum with 1Mpoints memory with single channel is 100MSa/s and this 1M can use only with 400us/div or more slow.
512k can use for single channel with maximum 400MSa/s and for 2 channel 200MS/s
Maybe FW/UI features are most good in Hantek but file handling is as poor as Owon.
It is big shame that Owon and Hantek have not SCPI. (Owon do not promise at all it later to this model, Hantek have give some kind of promises for SDK but... maybe endless "under design" status.
Owon can not command at all via USB.
I'm exactly same opinion with marmad. SCPI need be as "standard". This is very strong point in Rigol if need this.
Of course only small part of customers need it... but also it may be that there are more these customers who need it if this feature is implemented.
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Rigol have 16kpoints memory with full 1GSa/s
Hantek have 4k full
actually all these DSOs (except Rigol CA) are using too small FPGA to
capture whatever depth and full speed - in this case 2 x 4k or 2 x8k into FPGA memory.
This means here, both storing data into external SRAM (clocked at ADC clock freq., so for
Rigol 100MHz and Hantek 100/125MHz).
Sure, the sample rate is 1GSs for both, but you have to understand that writing
the information into external SRAM costs time, therefore Rigol is up to 3 times slower (wfrm/s).
And exact here Owon could be better (DDR2 vs. Synch SRAM), but probably it's not due
the typical DSO design (and the fact that they optimized design for 10Mpoints slowing
down by far the short memory mode).
Hantek have ... math and averaging possible only with 4k.
wrong, math (except FFT) works for 4k, 40k and 512k, avg only 4k
(i don't remember if Rigol was able to enable 1M and avgerage mode at same time, can someone test this?)
Sure Hantek could enable 40k (and deeper) for FFT, if i patch firmware i can run FFT even with 1M
and 400MSs, i can only gues that either their lazyness (there are many things which i can change in the firmware
without any negative influence on data quality or measurments error, why not everything is impelmented even
if the firmware/hardware would allow that can only be answered by HanTekway, but i guess lazyness)
was the reason to allow only 4k in FFT mode (as the span scale didn't match they would have to create
one per memory depth), or they didn't saw reason to fill FFT memory buffer with 400/200MSs
on 1GSs scope with 1024 points FFT.
I actually don't need here any magic or tuned memory depth, a FFT with 1/8/64k points would be better
than 1024 point based on what so ever memeory depth.
Hantek maximum with 1Mpoints memory with single channel is 100MSa/s and this 1M can use only with 400us/div or more slow.
512k can use for single channel with maximum 400MSa/s and for 2 channel 200MS/s
wrong, Hantek max. sample rate for 40k, 512k and 1M is 400MS/s for single channel
and 200MS/s for dual channel, these values are for 40us/div to 2ns/div.
Starting from 80us/div to 20s/div the sample rate is of course ging slower.
The SRAM is clocked with 100MHz (Rigol and Hantek), so Hantek is sampling 20% slower (8 x 100 vs 10 x 100)
but due the design (8 instead of 10 ADCs as in Rigol) the postprocessing time is shorter allowing
again faster updates (at least on paper).
I have no idea why Tekway changed right after they started with production firmware (a pre-production
firmware which was loaded on my unit was able to run with 500MSs when sampling with 1GSs) from 500 to 400MSs,
when i enable the 125MHz clock while in long memory mode my DSO does not have any issues to sample with 500MSs
(or 2 x 250MSs when 2 ch enabled). Maybe is was design decision to speed-up postprocessing.
Now knowing how Rigol and Hantek are made (amount of ADCs, FPGA clock, SRAM clock, phase shift for max. sample rate)
you can already see why they can't sample with 1GSs to SRAM, the max. sampling rate is actually given
by memory depth/2 when ADCs can be alligned properly -> so Hantek have 4 or 2 ADCs in phase with SRAM clock
to sample total with 400 or 200MSs, and on Rigol 5 or 2.5 ADCs for 500 or 250MSs.
Now when you measure on Rigol, which i did long time ago so don't blame me when this is not truth anymore,
the data is sampled only from 4 or 2 ADCs too, which means Rigols sample rate when in long memory
mode was for me 400 or 200MSs and not what in user manual.
(again, someone with current model could check that)
From what i can tell without any measurment, Owon is a winner here, their design can fill the long memory
with full ADC clock (however as above, somone could measure DDR2 clock to confirm that).
Hantek have give some kind of promises for SDK but... maybe endless "under design" status.
don't worry, it will be released soon for DSO1000B models (handhelds), but it is compatible
with Tekway DST1000B and Hantek DSO5000B.
SCPI need be as "standard". This is very strong point in Rigol if need this
full ack.
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There is something wrong in Hantek FW110806.0
This 1M memory do not work right.
If I look dots. 400us/div and then stop
100Ms/s
200us/div and it do not accept 1M selection and then 80us accept agen. Before I test I make my note to paper that 1M selection up to 400us/div and becouse 200us/div do not accept 1M, I simply draw x to my table and did not go more fast.
IF I have selected 1M and I go to 200us/div it do not change my selection but 806 have this common problem that it change memory without showing it in meny selection.
So If I make selection 1M with 400us it captures 100Ms/s
then I change to 200us, still 100Ms/s and menu mark is still 1M but it is not real.
But If I stay 200us/div and make memory selection..agen it do not accept 1M
Too fast I make my test and draw to paper that this is border. (I was surprice becouse I did not remember this from some older FW but also I did not find any ral test that what was real samplerates with all memory settings. I have some hantek table but there was not 512 and 1M sampling speeds in table for every t/div settings.
Math, yes my mistake: math FFT do not work but basic +-x/ works. And then average do not work.
Overall this memory amount and settings is somehow bad in this version.
So 1M works 400Ms/s with Hantek but with UI need be careful so that if scope drop out 1M it need select agen, even is scope menu show that 1M is selected. Basic math work with long memory, but not FFT and not average.
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There is something wrong in Hantek FW110806.0
This 1M memory do not work right.
right, all versions starting from 110728 to 110808 have this bug.
They should probably be never installed on production unit (except Hantek did it for reason, i mean cutted the
long memeory capability in 8ns/div to 2ns/div, but for me seems to be just a bug resulting from changed fine timebase
procedure).
I think i will make the 110531.1 downgrade firmware public available as long they not published the latest
one ( >= 110908.0 which have all these memory bugs fixed).
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This small example show what means long full speed memory. 2 x 10M.
Test setting:
Pulse generator generate 3 pulses out from two channel.
1. Channel 15ns wide pulse every 5ms
2. Channel 5ns wide pulse every 5ms and delayed 50ns after Channel 1.
I want capture this one random time coming three pulses so that all three come visible to display at once.
I set oscilloscope time 1ms/div and single shot and trigger to reasonable level. Scope is waiting.
After I trig pulse generator it generate these pulses one sigle "burst"
1. All three pulses are on the display, scope is now stopped after capture and waveform is in memory.
2. I want look first pulses. Shift horizontally
3. Zoom in with Sec/div and there they are.
4. Zoom in more.
5. Shift so that all can display and zoom in to 5ns/div. Yes pulses are ok. Total "zoom" is now 1:200000.
6. Scope run continuous and signal generator in continuous mode. Only for show what it looks continuous mode. (now there is Sin(x)/x on)
Captured 1ms/div single shot and then zoomed in so that 5ns/div. (of course it can littlebit more, 2ns/div but pulses can not display in one screen becouse delay time was 50ns)
This example show clearly what is Owon strong point in practice.
Simply with other scopes like Hantek, Rigol, Atten, GW, Siglent, Uni-Toy etc can not do it becouse lack of enough amount fast speed memory.
Of course this is only one special thing but in this, Owon is extremely strong.
Also you can try this with Agilent or Tektronix and look what model can do it.
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Here is example from Owon.
Front end. Over whole this input attenuator/amplifier area is normally soldered metal can and it cover area what are inside gold plated outer GND traces.
Also there are components behind PCB and also there is soldered metal can over area.
They have used very intresting RF amplifiers. Specially just before ADC
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A little offtopic, but is there any info if the "new" MSO (MSO7102TD, MSO8102T, MSO8202T) and PDS (PDS8102T/PDS8202T) scopes, which have a 2M point record length, have a full speed memory like in the SDS series?
According to the manual they have "2M points on each channel for the record length" - there is no word of "max" or limitations regarding the sampling rate. In contrary, the record length for the logic anayzer part is specified as "4M max storage for each channel" and later on there is a detailed specification which record length is possible for which frequency.
This sounds as if the 2M record length in scope mode was full speed (which is good) and can't be lowered for faster updates (which is not so good).
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I like this dso. I find it on e-bay for 375 euros with shipping.
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I like this dso. I find it on e-bay for 375 euros with shipping.
And your country possible customs clearance fees (small) and VAT18%.
After this, your scope price is around 440 - 450 Eur. Without any kind of customer care, without any kind of warranty. (yes you can send to Owon in China) Also if you want VGA version, check carefully what is seller selling.
With this or nearly this price you can buy it in european union area from reputable sellers who have import it and pay all taxes (VAT) and after then EU area no need pay VAT agen. Also some seller may have some warranty repair service and/or some after sales customer care, example as FW update service and so on. Some sellers in European union also sell fully burn in tested units. You know chinese factories QC is not best possible.
If you buy it directly from Owon as "1pcs sample order" you may get it around 470 Euro, including your country VAT18% and shipping with DHL and in this case if there is some problem, example DOA unit. You contact Owon and they change your unit as DOA units are ruled. You do not need gambling with these ebay sellers. What you trust more? Unknown chinese eBay seller or.... how about if unit is bad after arrive or after 1 month. Of course most of units are ok. But there is some risks.
What is cheap?
Cheap is not always cheap.
many peoples are fooled ebay prices. But it is not always so simple.
Example VAT, customs, customs clearace fees etc.. then also PayPal, they take littlebit with very bad currency rate.
True price is this what you have tottally used your money before goods are in your hand.
Cheap things are more easy becouse no need pay any customes and VAT's.
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Maybe there is
ADA4932
Relays, yes, same UD2-4.5 NU relays. Just same what also Rigol and Hantek etc have used. and they work - as they work. Where you can see test data where RF characteristics about these relays show problem? (yes, they are not best possible, but try make this kind of osciloscope ready in gift box with ~<$200 including workers salaries.. you need save every cent with every component... )
http://datasheet.octopart.com/UD2-4.5NU-NEC-datasheet-17791.pdf (http://datasheet.octopart.com/UD2-4.5NU-NEC-datasheet-17791.pdf)
Front end have 3 voltage bands. 2 of these have compensation adj.
This LMH6518 include programmable BW. Also 20M BW reject is there... and also upper limits. In my mind it is "interesting" solution.
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This LMH6518 include programmable BW. Also 20M BW reject is there... and also upper limits. In my mind it is "interesting" solution.
Owon is actually not using Linux, and the firmware is per model, so it is not just a easy model change like
on Rigol or Tekway/Hantek. A complette firmware dump from higher model (like on ATTEN or Tonghui)
will not work too becasue of the ADCs
What should work is firmware oatch to change the filter settings, i'm working on that right now.
Btw, if someone can find somewhere BSDL model for S3C2416 it would be great (file name something like s3c2416 jtag bsd)
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Some department of Xiamen Lilliput Ltd have some experience with WinCE and ARM..... becouse this conmpany do also some other things. Not only oscilloscopes. If they have somewhere in company design team who have allready WinCE developing knowledge and experience and tools ... Is it possible that.....
Example in Xiamen Lilliput GPS navigators they use ARM 400MHz and OS is WinCE.
Brand names are something like CARLIFES
(http://fuhuaxing.diytrade.com/sdp/420791/4/pl/0.html)
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no, it is not WinCE.
In principle they compiled a kind of own microkernel/bootload, which contains yaffs driver (necessary to read/write the NAND itself).
The bootloader is actually able to respond to some secret combination on UART, which i don't need/care for now.
Maybe the most interessting part of the bootloader is the fact that this is exact (or maybe a bit changed) bootloader as on
older Owon DSOs (they using S3C2440 like Tekway/Hantek, i believe the PDS/MSO series). In principle when you
type the secret combination you can download fw, flash NAND, erase it and so on. It also contains the encryption for NAND.
The rest of the NAND, well the actuall yaffs file system is containing few files only:
help
menu
dso app itself
FPGA file
BMP file (the logo)
TXT files (they a kind of settings for actual fw)
PARAM files (for setup savings)
HZLIB file (which is the encryption i guess)
There is additionally copy of all these files (so each file have a copy too).
/flash/boot/paramcp - params copy
/flash/boot/param - params file
/flash/boot/bmpcp bmp copy
/flash/boot/bmp bmp file
/flash/boot/txcp txt copy
/flash/boot/tx txt file
/flash/boot/mecp menu copy
/flash/boot/me menu file
/flash/boot/hlpcp help copy
/flash/boot/hlp help file
/flash/boot/hzcp hzlib copy
/flash/boot/hz hzlib file
/flash/boot/oscp copy of DSO app
/flash/boot/os DSO app itself
/flash/boot/fpcp FPGA design copy
/flash/boot/fp FPGA deisg file
The bootloader is in principle checking NAND, when something wrong copy will be used.
Now all these files, except the HZLIB, are sectored (2048 byte sectors).
These sectory are NOT the NAND OOB sectors, they are for the yaffs. Normally yaffs is storing
sector information in OOB area, Owon created (due the fast that they using own yaffs implementation and encyption)
additional own sectors.
Now these sectors are blank, but it should contain checksum (this is 20byte long, so 2028byte data + 20 byte crc per sector).
These CRC checksum is in the HZLIB file, so if you try to change something binary in the file you have to care about the
HZLIB too. For now this is not what i care about, crc can be always patched to valid. Maybe HZLIB is something else,
but it looks for me as CRC file.
What i'm doing now is to analyze the dso app itself to find what i need to patch first, when
this is done i will work on HZLIB/CRC. These blanks in code can be skipped for now, the code make sense
without them. I was only worrying that part of the data is in HZLIB, which is luckily not the case.
The hadrware itself contains also EEPROM, haven't checked what inside, but what i can see from NAND dump
the serial number is almost everywhere, so you can't just use firmware from higher model and re-flash
because you will get new serial number. However, this was anyway not what i was hoping to do, i think
it will be enough to find filter position in dso app, change the filter to well let say 650MHz (or maybe only 350MHz),
patch the HZLIB/CRC and reflash DSO.
Of course such modification will be overwritten when you do firmware update, but as Owon is anyway in
the opinion that the firmware is "mature" i don't think that many people will do updates monthly (like on other DSOs).
So for now i know what inside, where to look for what i wish to patch, where is the CRC - of course if this hack
will work not everybody will be able to hack Owon without proper tools.
You will need at least ARM JTAG (i still recomend H-JTAG), a driver for S3C2416/K9F1G08 NAND with OOB support
(which i wrote yesterday) and maybe a spare NAND when you worry about unexpected changes (it is always a good idea
to backup NAND, solder empty one, restore backup and work with that - EEPROM copy/backup make sense as well).
If someone have an Owon SDSxxxx and ARM JTAG and wish to play a bit, attached JTAG pinout.
In principle you don't have to disasseble everythign, it is enough to remove back cover to get access to
JTAG, sure when you wish to resolder NAND you have to remove all these f*** screws and PCBs.
Yeah, and of course every file is marked at begin and end with the name, so when you wish
to check/play with the DSO app itself, search for oscp, copy everything from there until you find
another one oscp marking, hex it looks like 01 FF FF FF 01 00 00 00 FF FF 6F 73 63 70.
As mentioned above you have then of course skip 20 bytes every 2028 bytes to get the real app dump,
aynway, have fun :)
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Btw, i'm still looking for the BSDL model for S3C2416 (file name something like s3c2416 jtag bsd).
This is because with that mode i can easily find on what pins the LMH6518 is connected to the S3C2416,
it can be GPIO/SPI and knowing what port is exactly used is what will help out to find the right
part of the DSO application itself to hack that baby to 350/650MHz ...
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Relays are the crappy NEC UD2-4.SNU: no specified insertion loss/capacitance, minimum contact rating 10 mV DC/10µA.
Definitely not RF relays!
well, i don't like these relays too, a good replacement are Omron G6K (mouser 653-G6K-2F-RF-DC4.5) ,
a really good replacement are Omron G6Y series (due no cap. load, they could be perfect for Tekway/Hantek,
but no SMD version available). All these relays costs a lot of money, remember you need 6pcs per DSO.
An aceptable alternative relay is FTR-B3GA4.5Z from Fujitsu, they have at least very low cap. values and
costs not that much. Rigol is using them for 300MHz models, i think you will find them too in Owon 350MHz model.
Minimum contact rating is not a big issue, most relays are working good with lower values.
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I am newbie at reversing (8-bit :) so can I try to quest what are you going to do?
So first you need to find what MCU/CPU pins are used as SPI interface because that
is how you find part of opcode, is that right?
Second, you need to find from datasheet of LMH6518 combination of data that limit
BW to 100MHz (or what ever).
Third, in "somewhere" your are going to search for opcode and data sequnce that
change parameters of LMH6518. That is how you are going to find what to change.
Am I close? Am I close? Am I close? Am I close? Ooooo boy am I at least a bit close?
What is hzlib (i find what zlib is), oob, bsdl? What is JTAG used for (yes I am that newbie 8)?
Is it possible that they have used some sort of packer and that packer is in zlib?
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I am newbie at reversing (8-bit :) so can I try to quest what are you going to do?
So first you need to find what MCU/CPU pins are used as SPI interface because that
is how you find part of opcode, is that right?
Second, you need to find from datasheet of LMH6518 combination of data that limit
BW to 100MHz (or what ever).
Third, in "somewhere" your are going to search for opcode and data sequnce that
change parameters of LMH6518. That is how you are going to find what to change.
Am I close? Am I close? Am I close? Am I close? Ooooo boy am I at least a bit close?
What is hzlib (i find what zlib is), oob, bsdl? What is JTAG used for (yes I am that newbie 8)?
Is it possible that they have used some sort of packer and that packer is in zlib?
1 - find JTAG on PCB
http://en.wikipedia.org/wiki/Joint_Test_Action_Group (http://en.wikipedia.org/wiki/Joint_Test_Action_Group)
2 - dump firmware from whatever memory on PCB.
In case of NAND flash dump OOB blocks
http://wiki.openmoko.org/wiki/NAND_bad_blocks#NAND_page (http://wiki.openmoko.org/wiki/NAND_bad_blocks#NAND_page)
3 - quick analyze firmware - is the code looking good? (i'm actually opening with hex editor only to see if the content looks good for me) If yes continue, if not sure solder empty NAND, restore backup and check if device is booting up.
4 - analyze hardware to quick understand what the hardware is suppose to do, read datasheets to find
function which can be used to achieve target (in this case bw hack)
5 - use Boundary Scan
http://en.wikipedia.org/wiki/Boundary_scan (http://en.wikipedia.org/wiki/Boundary_scan)
or just a continuity checker (when possible not) to find interessting/data flow pins (like the pins connected to LM6518)
6 - read S3C2416 data sheet and user manual to learn GPIO addressing, this is what you need to know
to be able to find a write sequence to specific GPIO pin or port (e.g. SPI)
7 - deep analyze firmware, look for control sequences. This is actually the part which takes the most time.
There can be always a kind of protection, the first step is to patch something simple like a string to see
what influence it have on the firmware protection - when this works change part of code to do something,
good example is change keypres code to do e.g. init or beep or whatever. Here on Owon this is a bit
more complex, but still these are first steps. When there is protection you have to localize it and remove first.
8 - build a test system - this is optional step, sometimes you can use dev boards from a specific chip to run dumped firmware
without any risk for DUT. In this case you could buy on ebay a cheap S3C2416 board, restore firmware dump to NAND
and analyze changes to firmware - to solder wires directly to PCB might be sometimes dangerous, so test system
will help.
9 - test changes on DUT, when everything works you almost done.
10 - investigate what will happens in case of firmware update - when still possible and all changes you made will
still works you done with hack - when not think about ways to autopatch during firmware update.
So that's all about reversing.
Now these hzlib, this can be crc table or it can be also chinese characters table :) I will see it during step 7
As for now the firmware is already dumped to separate files, i have also table of content (to be able to reflash changed parts into right sections), disasm (1st run )cleaned up (data, code) - however i don't like the result so i will have to get manualy
through code and re-analyze.
One important question is already answered "is Owon using LHM6518 to reduce bandwidth?" - the answer is YES.
This is a part of menu (some items hidden from user) :
aMenu_bandlimit DCB "menu_bandLimit",0
aMenu_20m DCB "menu_20M",0
aMenu_100m DCB "menu_100M",0
aMenu_200m DCB "menu_200M",0
aMenu_350m DCB "menu_350M",0
aMenu_650m DCB "menu_650M",0
aMenu_750m DCB "menu_750M",0
aMenu_fullband DCB "menu_fullband",0
which is exact what LMH6518 can do, so that's the confirmation.
Now the hack could be maybe something like "unhide menu", however there will be for sure a part
which is setting up 100MHz as defualt when "bandlimit" off so this need to be hacked too.
Another option is just to hack all 100MHz code parts to let say 350MHz.
I'm not sure if i can do everything in time, you have to know i loan Owon from someone and in principle
i have to send it back tomorrow (or buy it). However the work i doing now should be at least a good
preparation for future hacks, so someone else can continue in case i will be not ready in time.
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small update : FPGA design is protected by AES / CryptoMemory chip combination,
the firmware itself is usign AES too at least for firmware update, not sure if for other thing too ... i'm keep working on that.
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NEC UD2-4.SNU: no specified capacitance
i got few FTR-B3GA4.5Z (where the cap specs are available) and compared them to NEC UD2-4.SNU.
It seems that there is small difference, the NEC UD2-4.SNU have 0.2pF more for adjacent contacts and between
coil and contacts giving total of ~0.5pF higher as on FTR-B3GA4.5Z.
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Do you think this will make a big difference?
depends, on Owon didn't matter as all relays are in attenuator section and not between opamp/ADC.
On Tekway FTR-B3GA4.5Z instead of NEC UD2-4.SNU gives you immediatelly 2-3MHz more bandwidth.
On Owon there are other thigns which i don't like, input section/BNC ground
is floating - all BNCs (GND) are connected to one big piece of shielding which is solderend
only on one side to PCB, the another end is floating - this is from HF point of view bullshit.
Then no wall/shielding between channels (not in input stage nor between BNCs),
this is for me no go even on a 60MHz DSO. The wire between BNC and PCB is a joke too.
What else, yeah, the VGA out cable right over the trigger comparator and buck converter,
this is a really bad combination, all that garbage (1.25MHz) from buck converter and from VGA
out signal (when enabled) is "flowing" few mm above the comparator. This is a perfect noise
generator for trigger signal :P And of course trigger signal is coming from inout stage, so
the whole garbage is flowing then back to last opamp and ADC of course.
Can be even worse? Yes, it can, there is no GND layer (for reason) right under the VGA cable,
and gues what on the other PCB side? Right, the ADC clock chip.
How to fix these hardware bugs? Well, piece of shielding soldered to 3 caps and the front end shield
would good enough. It must be flexible and isolated (both sides !!!). That's for the trigger copm/ADC/buck/VGA disaster.
For BNCs is a bit more complex, you have to cut two walls and solder them between channels, solder the floating
GND, solder small GND wires directly from BNC to PCB GND and made a small wall for input stage too.
Unfortunately not everywhere a wall/shielding will be possible, there are holes for screws.
The device which i have, the big piece of shield with BNCs mouted to it, this part is already "moving around" a bit,
so later you will get definitely issues with GND.
These hardware "bugs" are typical for "compact" designs where lack of space will be recognized after all,
maybe Owon will improve that part in next PCB revision, they already improved some "jokes" in PSU part
of the scope. When there is no space to move parts Owon can at least solder a bit better BNCs,
solder the floatinng shielding and add 3 wires for BNC GND. then of course they have to solder small
shileding like on "good.jog" picture to protect trigger/ADC/clock from the buck/VGA garbage.
Total cost - 5USD per unit, so it should be possible for them.
based on the pictures of new PCB all these issues are obsolete!
Owon changed all these bad things, a big thumbs up for that Owon!
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Then no wall/shielding between channels (not in input stage nor between BNCs),
this is for me no go even on a 60MHz DSO. The wire between BNC and PCB is a joke too.
Sorry but I trust more real measured data than opinion. Example rise time and frequency response is lot of better than old Tektronix analog 100MHz work horses.
But why Owon -3dB point is around 140MHz if you tell that it is only just under 60MHz... and frequency response so that it have no lot of highs and lows. (and becouse this, it give also very nice pulse response - better than Hantek and better trig and less time error between channels (skew)). Pulse risetime is around 2 - 2.1 ns. Trigger is more stable than example Rigol or around same or littlebit better than Hantek.) Channel cross talking is also under specs limits.
If solder this BNC plate other side (holes) it is difficult to open for service (and it do not make any meaningfull change in measured data.) I can proof it (soldered and not soldered) - with real tests. It do not help anything.
Mechanical stress over product designed life time .. this plate is better to fix better.
Test data is imho more imporrtant than visual opinion about cold unit.
I trust only data.
Hantek have RF shielding but cover is not at all soldered.. its connection with RF is like zero also but if I solder it, no any change. Why?
I think Owon have learn this from old well known brand names. If they can do... why we can not do same?
But yes this design can do better just as all designs.
But first need data what proofs real problem and then data what proofs how much measured problem is better after change. But I have just opposite data - what proofs it work well and littlebit better.
But first we need real data what can show with real lab data that something is wrong. After data can design better, then test with real data. It is slow process. Lab data what proofs some problem is only whjat make sense - not opinions with eyes. Real measured data show if it works or not. I need tell that after I look also inside and make my "opinions" I have littlebit same feel as you. But my measured data "thinks" different.
Pulse response and frequency response shape is really good.
What is your RF opinion about this picture and who have design it. Chinese? No GND ... it goes around front panel here and there and long "mixed" RF way to front end.
What about frequency response. 10MHz? Who have design this HF bullshit ;) ?
(left side white/red wire is NOT GND wire! its meaning is tell probe data (division factor 1:1, 10:1, 100:1 etc) to scope)
Cross talk between these not shielded wires in freq area 0 - 200MHz is minimal. No any meaning becouse there are much more cross talk in other parts. If shield these wires you get nothing in practice. Scope is with 8 bit ADC. This leaking is well under this resolution. It is totally different case if we need care something around -60 ... - 120dB attenuation, example in good RF filters. There really need take care about RF isolating. And of course if go to hundreds of MHz or even GHz area. What is basic oscilloscope channel to channel cross talk. 20 - 40dB... and no need more. But yes making RF shield between these two wires... how much you can reduce total cross talk. What part of cross talk come from these two around 15mm wires. If make this crosstalk attenuation here theoretiocal infinite. It do not still help nearly anything... maybe some small part of one dB in total cross talk. You can try. So - why do it. Maybe becouse it looks better? This is reason why also Tektronix and HP did not care this problem. I have looked, tested, repaired, tons of HP/Tektronix scopes and other real RF stuffs. With my profession I can tell that these two part of short small wires do not crosstalk "anything" meaningful in tthis case. And yes, not wires soldered to GND. If solder GND wire from BNC to PCB. You can not see any advantage with any test instrument as we are talking now this scope case in its frequency area.
How can make this oscilloscope better. It need more sharp BW filtering in analog front end before ADC. Doing sharp brick wall filter so that -0.5dB is around 180-200MHz, -3dB corner is around 210MHz and -35 ... - 45dB around <=250MHz
(so -3dB point is better to move littlebit higher freg, from around 140MHz to near 200MHz but only if also do this brick wall.)
Also 250MHz noise from ADC system need reduce. If there is brick wall in analog front end then this can easy do also with DSP or maybe also better design in PCB around ADC. They have break National recommendations. They have not isolated well digital and analog part as recommended.
Trigger can do littlebit more clean. It is very well in this price class, nearly as leader but maube it can do better with some easy tricks BUT it need PCB totally redesign!
But, if do nothing... it still capture signal with better quality than many others in this price class...
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Later I have more pictures. Now Hantek fail most of pics to USB. Only this picture was ok. Hantek display allways ok stored but... then in home, USB have only 1 Hantek pic.
But later... I do it agen. (I do some test what maybe show something difference in signal capture quality.)
In this case both scopes get exactly same signal. Signal level is so adjusted that 1MHz with same level give 8 vertical division with both scopes. I set Owon to 5ns/div becouse 100MHz Hantek have not 2ns/div. Both scopes sample 1Gs/s. Owon was 1k mem and Hantek 4k mem. With 10k, Owon give so same that I can not see difference.
(BTW I find that if Hantek is set for 1M memory displayed waveforms update rate go extremely slow if compare to Owon with aroundsame settings and signal. This need more study.)
But wait some time... I can tell that this pic is nothing... not so bad for factory new unmodified Hantek... also Owon is fully unmodified. (after I get agen these noise and bullshit capture pics... maybe I want sensored some pics or give littlebit handicap to Hantek.)
210MHz in capture and stop. Both scopes get pure sinewave and level what is 8 vertical div p-p.
And if you think how is sine quality. It come from HP8644B. (test is not made exactly same time becouse I do not have good calibration quality isolating splitter.) Owon -6dB at 260MHz is nearly as in this pic, only level littlebit lower. Hantek capture there nearly garbage. But later... noise and other garbages. (this test was not short and simple and it really takes time.. so I need look what time I can do it agen. I do not like Hantek USB... never can trust if it store or not. How people can do work if tools do not work.
How this "error designed" Owon can beat 10-1 Hantek in all signal quality things, and also if look channels cros talk. Isolated wires or not but it works. Yes maybe Owon is 60Mhz ;)
This do not need opinions and believes, it need raw hard data from tests.
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cross talk have nothing to do with sampling, and you know that.
To be very honest i designed for years RF systems and things like the crap on Owon is somethign what i saw on
many devices. They did nothing else than copy/paste from bad design from a "known manufacturer".
Cost savings and stupid engineers are everywhere, today most of these so called engineers are googling for
solutions and not knowing what they doing, so you will find in the future more and more such design mistakes.
Don't forget, the same frontend is also used in 350MHz Owon models (and when i look into firmware even for more than 350MHz),
so it is not only "60MHz DSO", it is just a bad design, especially the very weak mechanical construction and bad GND will create many issues with the time.
The 250MHz noise is just another one example of "google engineers", they managed to read datasheet but not application note.
Sure, it not that critical on <200MHz models, but not nice at all. Let's hope they redesign a bit the 350MHz model.
Now Hantek, hehe, except some "calibration issues" on you unit (look what my DSO is doing, sine from R&S SMY and stop - no tricks)
this is something totaly different, just take a look on example picture in Agilent 5989-5732EN (page 9)
taken from LeCroy WaveRunner 104Xi. You will see that even 10x more expensive scope have same interleave distortion issues.
On Owon, as no external interleave has been used the waveform looks of course better, but this is nothgin new.
Btw, you know exactly that especialy Owon will not do anything when we not push them, so no need to hide potential issues from users.
For these already few selled units, a small fix can be done by the user to improve these (not bad at all, even if i don't like here and there few things) devices.
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... and because i love to "fight" with you, here pictures of 250MHz sine shot on my Tekway.
Sure, on default calibrated unit the picture will be in worst case like on your Hantek,
with my optimized factory calibration you will get better results.
Sometimes the issues are not on hardware side, sometimes they created by lazy employees.
The engineer who deigned the original Tekway firmware implemented 16 calibration values:
coarse 1GS/s edge
coarse 1GS/s pulse
coarse 1GS/s slope
coarse 1GS/s O.T.
coarse 800MS/s edge
coarse 800MS/s pulse
coarse 800MS/s slope
coarse 800MS/s O.T.
fine 1GS/s edge
fine 1GS/s pulse
fine 1GS/s slope
fine 1GS/s O.T.
fine 800MS/s edge
fine 800MS/s pulse
fine 800MS/s slope
fine 800MS/s O.T.
now what you will find on Hantek is only 3 of them
coarse 1GS/s edge
coarse 1GS/s pulse
coarse 1GS/s O.T.
has been executed during production - what a shame.
My scope is using only 6 of them (i don't need coarse values, fine are better but you need good equipment to run them):
fine 1GS/s edge
fine 1GS/s pulse
fine 1GS/s O.T.
fine 800MS/s edge
fine 800MS/s pulse
fine 800MS/s O.T.
which is already a big improvement, i haven't found time to test the missing 2 values (slope 1GSs/ slope 800MSs).
But we should focus in this thread on Owon and not jump to other products.
Maybe some of the Owon issues are also based on lazy employees, who knows (well Owon do).
Our "job" is to blame them a bit to force them to improve their products,
because there is nothing mature on these units
starting from these crazy buttons, firmware logic, missing features, trigger out joke, update rate, noise here and there,
missing shiledings, floating grounds, mechanical construction (BNC), missing fan monitoring (what happens when the
fan stop to work? right, ADC and FPGA will get damaged too).
Nevertheless, i think i will keep my SDS7102 (or buy SDS8102, i have to think about) as the hardware/software
even with these bugs is still worth money. The mechanical issues can be easy fixed, shileding as well,
the 250MHz noise will be bit harder to fix but as already said abiove - for someone who will never ever hack the
hardware to more bw than 200Mhz this didn't matter that much. I will probably cut the power supply
from ADC and install my own inside, there is enough space for that.
I was a bit busy with other things, so no hack news for today, but tomorrow i have nothing in my calendar,
so i will "O(h)won! a bit" the firmware
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cross talk have nothing to do with sampling, and you know that.
The 250MHz noise is just another one example of "google engineers", they managed to read datasheet but not application note.
Sure, it not that critical on <200MHz models, but not nice at all. Let's hope they redesign a bit the 350MHz model.
Btw, you know exactly that especialy Owon will not do anything when we not push them, so no need to hide potential issues from users.
Yes of course I know this. But I was reading you see these "not isolated" short wires some problem.
Becouse I talk SDS7102 and no other models they are not problem. Then I was thinking why you see this problem and I can not imagine any other that possible thinking about cross talk becouse no shield there. I can tell, there is no cross talk problem and no reactance problem as we talk 100MHz oscilloscope. GND, what is problem? Why it is not problem in HP and Tektronix? Becouse there is no problem. It is problem only if ageing make loose this connection. Of course if we go to 200, 300, 400 etc MHz this construction go more bad. I have looked front end with signal eyes... using HP VNA. There is no problem as we think this is 100MHz oscilloscope.
250MHz noise, still quite low level, but this I do not like and there is cheap "engineer" bad job just as you tell... read datasheet but forget then all other things. This ADC area design on the board is not good. It is good if thing this class normal cheap scopes. But it can be better very easy.
Yes we need push Owon to develop it better but this here is not right way.
But how much better it need be than others in same price class. Now its HF characters beat all in this scope class.
If we want they develop it better we need talk with Owon.
And do not compare apples and oranges... we need copare unmodified units... just from factory.
This is what peoples buy. But yes we can also destroy all these names. But who win then. Nobody. Then there are only loosers.
--------
ADD:
About cross talk/RF isolation.
I have done (indirect) measurement. This is not exactly how it need do if think scope itself as test instrument and how much it see himself this.
but this difference tell still something.
I connect 0dBM signal to CH1 and listen CH2 with R&S spectrum analyzer only for look level.
Hantek, 100MHz in level 0dBm, CH2 can see around -90dBm
Owon, same, CH2 can see around -53dBm
(remember, this is NOT what scope see as channel isolation)
This is really big difference if this is some other unit than 8bit ADC oscilloscope. In this kind of oscilloscope this do not mean nearly anything. If this is example RF filter, this difference is just as bullshit and exellent. But if Owon do 300MHz scope with exactly same front... this do not work well. I have never test Owon 200 or 300MHz models. Only what I know is this 100MHz model and becouse this, I can talk only about this. All other talking about other models are only believe and religion if have no real data.
Btw this picture before was taken this "world famous and every lab trusted Tektronix" (this pic was model 2236... there have been 100MHz professional RF designers.. heeh.. and they proud talking they are simple - The best. ;)
But I need do all other my tests agen, not only becouse this USB issue. Today I find that this single Hantek have some kind of fail! So I can test after this fail is solved or after I can get other unit for test. So, also this 210MHz picture may change later becouse after find this fail I can not repeat this picture as it was before. Something happend nearly or same time after I update this unit for FW 110909.0 Trigger do not work right, frequency display is totally wrong, also all times this unit start so that display is lowest light... always after start need ghange "contrast" to normal. Also now -3dB point is around 100MHz and lot of some kind of wobble/jitter. Very strange..
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I connect 0dBM signal to CH1 and listen CH2 with R&S spectrum analyzer only for look level.
on Hantek 100MHz in level 0dBm, CH2 can see around -90dBm
on Owon same measurment, CH2 can see around -53dBm
i measured -48dBm on Owon, so not that far from your measurment. So in best case scenario ch2
will have 0.65LSB crosstalk (under 0.5LSB is what it should be) in worst case 1DIV!
Even if these values are not the true channel isolation values i don't like them.
Today I find that this single Hantek have some kind of fail! So I can test after this fail is solved or after I can get other unit for test. So, also this 210MHz picture may change later becouse after find this fail I can not repeat this picture as it was before. Something happend nearly or same time after I update this unit for FW 110909.0 Trigger do not work right, frequency display is totally wrong, also all times this unit start so that display is lowest light... always after start need ghange "contrast" to normal. Also now -3dB point is around 100MHz and lot of some kind of wobble/jitter. Very strange..
not a surprise, Hanteks QC is sometimes the world worst, i have no idea what these guys doing.
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I connect 0dBM signal to CH1 and listen CH2 with R&S spectrum analyzer only for look level.
on Hantek 100MHz in level 0dBm, CH2 can see around -90dBm
on Owon same measurment, CH2 can see around -53dBm
i measured -48dBm on Owon, so not that far from your measurment. So in best case scenario ch2
will have 0.65LSB crosstalk (under 0.5LSB is what it should be) in worst case 1DIV!
Even if these values are not the true channel isolation values i don't like them.
Yes it can be better but if think all other inaccuracies and specs it is not real problem. but, if think perfect, it is not at all nice. Specially becouse it can do so easy better without any money... oh yes jiao is also money in China.
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There was a comment in another thread (https://www.eevblog.com/forum/index.php?topic=4597.0) that a new SDS firmware should have been released end of last week or so.
Is anything known about it? Like: what has been fixed/improved and if it's freely available somewhere?
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There was a comment in another thread (https://www.eevblog.com/forum/index.php?topic=4597.0) that a new SDS firmware should have been released end of last week or so.
Is anything known about it? Like: what has been fixed/improved and if it's freely available somewhere?
Afaik there is no public downloadable. You ask seller - if you have buy it from responsible Owon reseller.
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Here are some pictures. Every parallel pair have exactly same signal.
One finding was that slower horizontal speeds using long memory, Hantek waveform update rate go extremely slow (FW bug?) , far far below Owon. But 4k memory Hantek waveform rate is most cases faster becouse Hantek is tiny DPO and Owon is DSO. Last picture show Hantek timing problem. Skew, and with new FW also trig position is wrong. Owon trig position is overall more accurate.
Owon ADC is much more advanced than Hantek. Surprice is why Owon do not it better becouse they have these building blogs in HW. Better design and it is just lot of more better, now it is only slightly better. Also becouse Hantek ADC is nearly like garbage generator they use heavy signal cosmetical cleaning in FW. But from pixel porridge they develop some kind of nice looking cake to show on display. Where is true signal under test... "who knows - who cares" we have "oscilloscope"
I did not take all pictures also with analog scope... if I take... then all you want analog scopes. But no one do not want this becouse these can not make cheap... (exept some real bullshit)... (oh but not... you can not save pictures to USB/Computer and loose working time with computer play....hehe)
I do not explain all pics... look and they tell all you need, they are self explanating. (oh yes signal levels are same and first sinewaves so that 1MHz is 8 div. All next sinewaves exactly same level and signal is really clean (HP8644B). Cursors are -3dB related to this level.
Also I know these picture sizes. They are not nice on forum and PC display but I want they are native resolution.
In owon pictures these blue color areas are clean in scope display and stored .bmp but my converson to .gif make this small cosmetic problem.
Pictures 14-16 (triangle wave) this waves originally have in upper ans lower turn point this small backfolded v shape. With good analog scope it can see clearly. Only Owon find it. Hantek loose it totally inside sampling "noise".
ADD becouse asked:
---------------------------
1. 1MHz sine, level 400mVp-p for reference, look Hantek noise.
next all sinewave pics are done with same signal level. (in scope end also terminated with HP 50ohm terminator enough good to 300MHz)
2. 100MHz Both scopes well but Hantek loose clearly.
3. 140MHz Both scopes around -3dB, Hantek signal is clearly "wobbling"
4. 180MHz Owon continue perfect work, Hantek level is around -6dB and high wobbling.
5. 200MHz Owon is not yet -6dB and Hantek wobbling is terrible. Looks more bad in live running.
6. 230MHz Owon kontinues perfect and not yet -6dB. Hantek - well it see "something" and still it can do trig. But nearly useless.
7. 270MHz Owon reach -6dB point but signal is still perfect and without wobbling. Hantek have loose trig and show only random garbage.
8. 350MHz Owon continue, no markable wobbling, signal attenuated highly, no any kind of trig problems. Hantek Have really loose all.
(Note: With this signal and adjust, Owon trig to 410MHz, highly attenuated signal and there is wobble just something like picture 6 with Hantek)
9. Not nice noise in Hantek.
10. Captured square wave and then 11 and 12 zoomed in this captured signal in stop mode.
17. Notice Hantek skew. CH1 and 2 have time error. Not much and it can compensate easy with cable lenght. (delay this channel what is first).
But then, there is also problem in trigger. Over one div (around 5 ns) error.
This error is strange. If change time/div setting (scope stopped) it disappear and come agen. FW bug?)
-----------------------------
Then one thing not related to these pictures directly.
Hantek is very superior slow if use long memory.
In fast speeds and short memory, Hantek have much more wfrms/s than Owon. (Owon work in this case as DPO and Owon always as serial processing DSO)
But situation go opposite if use 40k to 1M memory with Hantek. There wfrms update rate is much better in Owon. Even 10M it do more fast than Hantek 1M.
Of course if use very slow speeds and sampling speed is so slow that it come meaningfull then all scopes are slow of course. All understand that 10Megasample memory with 1 Mega sample per second take 10 second to capture but here I do not mean this time.
What happend there inside Hantek, this I do not know. Something in memory handling. What hell they do with captured data in memory before they show it to user. What takes so long time?
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and more. Yes I use Owon CH2 so yellow...
TST10 is captured normally. With settings you see.
Both scopes 1M memory.
TST11 and 12 are this same capure, scopes "stop" mode and "zoomed in" using time/div knob.
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Note: for .jpg and partially also for .gif. Owon store screen dumps as .bmp. I do not understand why my .bmp to .jpg conversion destroy colors and aslo bmp to gif. And if I convert to .gif it sometimes destroy some lines or other details and render some colors area badly.
So THIS display quality is NOT Owon display quality, it is irfanwiev bullshit converter. Specially it destroy red color if it is in small details as thin lines. Next bad is yellow handling. But .bmp is too big, waste of server capacity. This effect you can see left bottom corner. On Owon display you see these "balls" and there inside channel numbers. These yellow and red are exactly same tone and brightness on the real display text and captured trace... but not at all in this converted picture. With photographs I have trust irfanwiev becouse it is simple and fast... but with this kind of pictures it is just most bad bullshit what can be. So text and trace display brightness is just same as these balls left bottom.
Read this note about picture quality before open picture.
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GIF is an obsolete 256 color format and JPG is designed for photographies, so I'd suggest to convert to PNG. Also maybe you should use a decent free program as Photofiltre (http://photofiltre.free.fr/).
I always use it in the job to convert scope screenshots to PNG for mails or documentation. As it's a simple paint program, you can also draw some rectangles to highlight findings etc.
As an alternative, there is also Paint.NET (http://www.getpaint.net/), but I kinda prefer Photofiltre, as it's small and quick and basic (in a pleasant way).
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attached Owon frontend (without trigger mux, sample/hold and REF DAC).
I wish i could draw rest of the DSO, but to e very honest the blue PCB is making me crazy,
maybe someone with better eyes can do the rest.
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attached Owon frontend (without trigger mux, sample/hold and REF DAC).
I wish i could draw rest of the DSO, but to e very honest the blue PCB is making me crazy,
maybe someone with better eyes can do the rest.
Very nice work.
Please can you check R10, C4 and C8 values. Feels littlebit strange.
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attached Owon frontend (without trigger mux, sample/hold and REF DAC).
I wish i could draw rest of the DSO, but to e very honest the blue PCB is making me crazy,
maybe someone with better eyes can do the rest.
Very nice work.
Please can you check R10, C4 and C8 values. Feels littlebit strange.
C8 is 100pF, only the text above the cap is wrong, should be "C8 + C10 cal value 136pF" not 22.5pF
I have measured both together, from trimmer color code C8 might be 100-120pF
R10 is 01B which is 1k, so no error on schematic
C4 is measured 872pF, so next value is 870pF, no error on schematic
All caps values are real measured off board values, so they should be not that far from the real value.
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btw, i wrote before that the VGA out and buck converter nosie will be feeded back to opamp/ADC,
now from the scheamtic you can see this is not truth. The LMH6518 have separte and buffered aux output,
so the noise have only influence on trigger signal but not on ADC directly.
The indirect way, trough PCB/clock chip is os course still given, but this increase only phase noise of clock a bit,
so not really big issues on under 5k USD device.
Having not the frontend scheamtic should be clear for everybody that there is no bw/alias filter
before LMH6518, so everything is done within that chip.
Hack update - hack over AES implementation hole is working, so i can flash my own firmware but for some reason
it is not working properly (i don't have any menu heh). I ordered now a S3C2416 board and will continue
on that, i just don't wan't to shot the CryptoMemory chip because then i can throw the DSO in scrap.
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attached Owon frontend (without trigger mux, sample/hold and REF DAC).
I wish i could draw rest of the DSO, but to e very honest the blue PCB is making me crazy,
maybe someone with better eyes can do the rest.
Very nice work.
Please can you check R10, C4 and C8 values. Feels littlebit strange.
C8 is 100pF, only the text above the cap is wrong, should be "C8 + C10 cal value 136pF" not 22.5pF
I have measured both together, from trimmer color code C8 might be 100-120pF
R10 is 01B which is 1k, so no error on schematic
C4 is measured 872pF, so next value is 870pF, no error on schematic
All caps values are real measured off board values, so they should be not that far from the real value.
Thank you recheck these. These values feels strange (still thinking why they are as they are) and I was afraid some typing error. But now it is as it is.
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Here same signal to three different scopes.
Owon, Hantek, Tektronix old analog scope (not very good one)
(Tek display have no focusing problem... but camera and eye is different. (also you see light difference, where electron beam use more time then phosphor is more bright... but camera dynamic is always very poor, far below animal eye... so it looks different as with eyes. But this brightness isnclude also information...) This analog have only normal basic phosphor type display. Not this special fast drawing microchannel tube. But this is not now meaningfull.
Tektronix signal was connected to input as Hnatek and Owon. With T and 50ohm terminator.
Tek have also 50ohm input (real, not "fake" 50 ohm.) If use this, signal is more pure square and also risetime then around 1.55 - 1.6ns. (signal itself on the generator output connector is 1.3ns rising)
Oscilloscope is for analyzing "unknown" signal.
What you analyze, you signal under test or your scope?
Both scopes, Hantek and Owon need better front end.
Specially it is useful for Owon becouse Owon ADC quality is enough for better front end.
I do not mean front end need be so different. But it need better "component final adjust" for better frequency and phase characteristics. No need change principle. Principle is acceptable enough. Input protection maybe need be better. I littlebit afraid it is easy to get "smoke out".
(Btw, Hantek pic show also this trigger bug.)
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As asked, 10kHz square to both scopes and all settings same.
Then littlebit different.
(this sweep can not do with Hnatek becouse persistence can not use, so only with Owon.
Last pic is Owon 435MHz test, not 145MHz as read in picture file name. test. With 5MHz freq mod and with 100kHz modulation freq (not meningful here.) Zoomed 10x. Middle is 436MHz (1MHz wrong if my signal did not change),whole pic area is 75MHz.
Then turn also Hantek to around 435 MHz and zoomed 10x. With same signal as Owon, of course there is nothing (note also f resolution)
Then same without any signal. Btw, what do Hantek designer... maybe he have never heard name Nyquist.
Middle of 500MHz sweep and 1x zoom there is 250MHz noise in Owon. If use this sweeped freq response as flatness correction it can think that 250MHz noise is only 40dB below this level input signal - This is not so meaningful if think 100MHz scope but still it is not nice becouse reason is maybe only loose design - lack of reading National application notes. I also believe that 200MHz model do not have this, it maybe have 500MHz noise becouse different faster ADC. (signal itself was 30mVrms and oscilloscope channel 1 was set 10mV/div ( around 8.5div p-p) in scope mode. FFT filter set Hanning.
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Hi Tinhead,
Any suggestions on how to mod the Owon? :)
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Last pic is Owon 435MHz test, not 145MHz as read in picture file name. test. With 5MHz freq mod and with 100kHz modulation freq (not meningful here.) Zoomed 10x. Middle is 436MHz (1MHz wrong if my signal did not change),whole pic area is 75MHz.
oh yeah, i like that picture. No chance to get anything similar on Hantek due autopersistency, time to patch?
Probably ...
Any suggestions on how to mod the Owon? :)
not yet, currently i'm waiting for an S3C2416 board to continue my work.
There are some on ebay, but they bad designed. I found two companies producing what i need,
one of them not responding (as they probably on holidays), another one out of stock (have to wait extra week).
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Thanks for the analysis on the 'scope. I've been thinking of buying the same owon model.. I could really use the battery option, which many other seem to lack. So I'll definitely read through the whole thread once I get the time =)
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I wonder: is it clear at this point if the SDS7102 is essentially the same as the SDS8102 and the SDS8202 (or even the SDS8302 or SDS9302) from a hardware point of view? Or do the models with 2GS/s and more have also different ADCs and input circuitry?
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I wonder: is it clear at this point if the SDS7102 is essentially the same as the SDS8102 and the SDS8202 (or even the SDS8302 or SDS9302) from a hardware point of view? Or do the models with 2GS/s and more have also different ADCs and input circuitry?
ADC on SDS8102 and SDS8202 must be different than on SDS7102, it should be MXT2001 instead of MXT2002.
On SDS8302/SDS9302 we can only guess what inside, but probably (in worst case) it is/will be still MXT2001
with overclocked clock to 1.25GHz/1.6GHz or maybe ADC08D1500 (in best case) - which i really doubt because
of the price (ADC08D1500 costs 500USD at 1000pcs and SDS8302 only ~1000USD)
Regards the frontend, the firmware looks universal, so you can assume the frontend will be the same.
You can actually even simulate based on the schematics that this works fine for 300MHz.
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There was a comment in another thread (https://www.eevblog.com/forum/index.php?topic=4597.0) that a new SDS firmware should have been released end of last week or so.
Is anything known about it? Like: what has been fixed/improved and if it's freely available somewhere?
I believe the firmware update for the SDS7102 fixes the problems described in these posts:
https://www.eevblog.com/forum/index.php?topic=4597.msg62352#msg62352 (https://www.eevblog.com/forum/index.php?topic=4597.msg62352#msg62352)
https://www.eevblog.com/forum/index.php?topic=4412.msg62228#msg62228 (https://www.eevblog.com/forum/index.php?topic=4412.msg62228#msg62228)
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You can actually even simulate based on the schematics that this works fine for 300MHz.
You trust simulators on this? Where parasitic behavior may be the major contributor?
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There was a comment in another thread (https://www.eevblog.com/forum/index.php?topic=4597.0) that a new SDS firmware should have been released end of last week or so.
Is anything known about it? Like: what has been fixed/improved and if it's freely available somewhere?
I believe the firmware update for the SDS7102 fixes the problems described in these posts:
https://www.eevblog.com/forum/index.php?topic=4597.msg62352#msg62352 (https://www.eevblog.com/forum/index.php?topic=4597.msg62352#msg62352)
https://www.eevblog.com/forum/index.php?topic=4412.msg62228#msg62228 (https://www.eevblog.com/forum/index.php?topic=4412.msg62228#msg62228)
FW update have two things repaired. (also maybe some unknown minor things?)
1. Repaired bug in FFT frequency cursors if FFT window is x2, x5 or x10 zoomed and/or horizontally shifted. Cursors frequency info was totally wrong. Repaired.
2. Repaired waveform save to USB if used oscilloscope slow speeds modes.
This problem was only in slow speed modes, not high speed modes. (1)
Note: Current version of PC software can not open and/or convert these to csv.
Captured datapoints are ok in saved file. File header have some conflict with PC software somehow related to timebase and scope mode (slow speedmode/high speed mode).
Header is 69 bytes long. After this header start captured datapoints 1k, 10k, 100k, 1M or 10M bytes lenght. Every datapoint is 8bit signed value. File can open if littlebit mod header with editor. But there need change t/div value so then PC software displayed timebase is wrong. And also if convert to .csv file, there is then wrong timing info.
Owon need repair this PC software.
(1) Scope have two major time band. High speed and Slow speed.
High speed is 50ms/div -- 2ns/div (1ns/div in 8202 and higher)
Slow speed is 100s/div --100ms/div
High speed band works normally. Not affected in this memory, samplerate, save to USB issue.
Slow speed band have two different modes. Scan mode, Normal mode.
Scan mode is used if 100ms/div to 100s/div speed setting AND trig is "Auto"
- scan mode is like roll paper penplotter. It use slow samplerate. It is feature not bug. Display info about mem and samplerate is wrong, it is bug and still not repaired.
Normal mode is used if 100ms/div to 100s/div speed setting AND trig is "Normal" OR "Single"
- in this mode you need wait it have meet trigger and then capture rest of signal. (before trig id do of course hidden pretrig sampling loop) After whole data is captured it is displayed.
In this mode it use highest possible sampling speed related to selected amount of memory.
In this mode you can also stop shift and zoom using "Horizontal position" knob and "Sec/div" knob. (time shift is more fast if first zoom out then shift and then zoom in) In this mode you can also save waveform to USB (as mem selected 1k - 10M) but this mode saved wave file PC software can not open. (waiting fix)
----------------------------
About 8202 and higher.
Front end from BNC to ADC is enough for all these frequencies.
Maybe there is some minor adjustments in some resistor/capacitor value (or maybe not - maybe they use different front end, this can know only after inspect these models, but if they have done it with sanme front end, it is well possible).
This front end desig have not problems upt to 300 or even 400MHz if we are talking related to these things what low end or even middle level oscilloscope need. (maybe shielding need be littlebit better between channels). This is so clean three voltage band one road attenuator front end.
This can easy see also my pictures. Example in pics where is sweep up to 500MHz in FFT mode.
Also there is set of pictures with different frequencies sinewave, and pulses. (of course I have more)
With my own inspection I can tell (opinion) that changing ADC and littlebit adjust/reduce higher frequencies attenuation it can easy be 300MHz oscilloscope just with this front end. (in theory and in practice and with just this PCB)
But what I hope is: in all models they change PCB design just around ADC. GND's layout need change and Power to analog and digiltal part of ADC chip need RF isolation. (it works but it can be better without money) Also they can littlebit develop some HF/RF shielding also it may do it better without money. Also body where BNC's are assembled can easy be littlebit better.
Front end / ADC system meets very easy all frequancy specs without any changing. You have loook these Rigol/Atten/Siglent/Uni-Toy pictures around internet. This Owon is in captured signal quality far over these.
Also before I have tested example Rigol 50 and original 100MHz models. Owon is far above these in capture quality.
Also frequancy response is better. Response shape is better, this need also remember, not only look -3dB point.
Now this 100MHz scope step response is around 2ns rising time and -6dB point is around 270MHz.
And becouse there is not interlevaed style ADC there is not ADC timing and level match problems.
Only what need do is reduce higher frequancies attenuation!
If want 7102 freq response -3dB point over 200MHz it is maybe possible with small HW mod?
No need software knife for LMH6518. It looks that it is not set 100MHz by FW. It is maybe set to 200 or 350 becouse freq response is what it is. Look whope front end and LMH datasheet and response curves... my opinion is that it is set for 200 or 350MHz(?). If it is so and as we know total curve it can think that around 200MHz it can rise some other way.
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You can actually even simulate based on the schematics that this works fine for 300MHz.
You trust simulators on this? Where parasitic behavior may be the major contributor?
no, by default i don't trust any simulator.
This time it is easier, when you look on the PCB picture you will
see that components from ch1 and ch2 are placed in different locations. So that means even with not exact
same mechanical design (and resulting parasitics) both channels are working smooth enough.
Additionaly the measurments done by rf-loop confirming my observations.
I haven't measured directly on PCB how the signal look like (let say up to 300MHz) right before LMH6518,
maybe rf-loop can do this (as i send back Owon).
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Hi there,
my SDS7102 arrived just yesterday. As I do not own a Windows machine, I decided to implement my own version of the PC software using Python and Qt. I found some specifications about the USB protocol here (http://sourceforge.net/projects/owondriver/files/). Unfortunately, either when using PyUSB, or using the driver provided in the link above, the connection times out when trying to read from the scope. I guess OWON might have changed something about the USB protocol in the SDS series. Before I try to contact OWON and get some information regarding the (potentially) new USB protocol, it would be great if someone could replicate this finding.
If you own an SDS scope and a Linux machine, please try to run the already existing Linux driver (http://sourceforge.net/projects/owondriver/files/owondriver/owondump-0.3/owondump-0.3.tar.gz). Alternatively, you could install PyUSB 1.0 (http://sourceforge.net/projects/pyusb/files/PyUSB%201.0/1.0.0-alpha-1/pyusb-1.0.0-a1.tar.gz) and run the following code:
import usb.core
VENDOR_ID = 0x5345
PRODUCT_ID = 0x1234
WRITE_ENDPOINT = 0x03
READ_ENDPOINT = 0x81
CONFIGURATION = 1
INTERFACE = 0
START_COMMAND = 'START'
RESPONSE_START_LENGTH = 12
USB_TIMEOUT = 2000
dev = usb.core.find(idVendor=VENDOR_ID, idProduct=PRODUCT_ID)
if dev is None:
raise ValueError('Sorry, mate! No OWON scope found...')
dev.set_configuration(CONFIGURATION)
ret=dev.write(WRITE_ENDPOINT, START_COMMAND, INTERFACE)
if ret is not len(START_COMMAND):
raise ValueError('Writing failed...')
data=dev.read(READ_ENDPOINT, RESPONSE_START_LENGTH, INTERFACE, USB_TIMEOUT)
print data
If you find any read-timouts, please get back to me!
Best,
Chinakoch
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This "guidance" manual is old version what can find there.
I will send later link to you for more new guidance manual if it helps anything. (updated manua know also SDS models)
Also in new manual have maybe something wrong specailly in part of data structure.
IMHO this driver is for old models. No one have been interest to update these becouse they are these "open procect stuffs"
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This "guidance" manual is old version what can find there.
I will send later link to you for more new guidance manual if it helps anything. (updated manua know also SDS models)
Also in new manual have maybe something wrong specailly in part of data structure.
IMHO this driver is for old models. No one have been interest to update these becouse they are these "open procect stuffs"
Thank you very much, rf-loop! My first guess was, that endpoints or the 'start command' might have changed. Anyway, I can not confirm this for the data given in the new manual. So it is maybe just my dilettante programming or other reasons I can not foresee right now...
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Using some magic software tools, I can now confirm, that my first guess was right and OWON has indeed changed the 'start command' in the USB protocol for the SDS. I am now able to get data from the scope. As I do not know if OWON wants details about their protocols made to be public, I will not post any details here.
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Using some magic software tools, I can now confirm, that my first guess was right and OWON has indeed changed the 'start command' in the USB protocol for the SDS. I am now able to get data from the scope. As I do not know if OWON wants details about their protocols made to be public, I will not post any details here.
I think it is not problem publishe and share what you have your self find and know, I think it can make public.
Owon have been somehow open mind as they have be very helpful for develop this old linux driver.
Only what I ask is that do not publish/share this "new" guide as Owon published official material becouse it is not officially give for share and it may have obsolete or wrong information. ( I think this new Guide is not yet ready... and as we all know wrong information is more bad than no info...)
I think Owon (this is only my individual citizen opinion) is happy if someone help other peoples example so that linux driver can use also with this SDS
If someone want do full develop for open driver, I think if he/she do seriously this project also Owon want give help or some cnowledge for this work just as they have done before.
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Is it possible that the SDS series is a little picky about USB sticks? I received my 8102 today and tried to store screenshots and waveforms to an USB stick which failed more or less completely. Only in slow acquisition modes and for a 1k record length, the SDS wrote at least a (very small) BIN file to the stick, but the Windows software showed it was empty. For any higher record length in faster acquisition modes or when trying to save a screenshot in any mode, the saving never finished (or even started).
I tried to reformat the (16GB) stick in Win7 and XP (Fat32), but with no success. I also tried a 2.8" USB-HD (also Fat32) which behaved the same. Also another 8GB USB (again Fat32) stick failed.
Only when I reformatted the 8GB stick on my XP netbook, the SDS would finally store screenshots and waveforms to this stick (and only to this stick). I'd suspect the SDS is limited to certain block sizes or whatever, but this is a bit frustrating.
My FW is v1.0 btw. which is obviously not the newest version (there was an v1.0.1 on devices bought in August) . I already contacted Owon and hope that they can provide me with a firmware that has a little more stable USB support.
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Is it possible that the SDS series is a little picky about USB sticks? I received my 8102 today and tried to store screenshots and waveforms to an USB stick which failed more or less completely. Only in slow acquisition modes and for a 1k record length, the SDS wrote at least a (very small) BIN file to the stick, but the Windows software showed it was empty. For any higher record length in faster acquisition modes or when trying to save a screenshot in any mode, the saving never finished (or even started).
I tried to reformat the (16GB) stick in Win7 and XP (Fat32), but with no success. I also tried a 2.8" USB-HD (also Fat32) which behaved the same. Also another 8GB USB (again Fat32) stick failed.
Only when I reformatted the 8GB stick on my XP netbook, the SDS would finally store screenshots and waveforms to this stick (and only to this stick). I'd suspect the SDS is limited to certain block sizes or whatever, but this is a bit frustrating.
My FW is v1.0 btw. which is obviously not the newest version (there was an v1.0.1 on devices bought in August) . I already contacted Owon and hope that they can provide me with a firmware that has a little more stable USB support.
Also there may be "slow speeds" bug (USB save bug) in your scope, same as old 7102 FW have and what is later repaired. (also same time repaired FFT frequency cursors). Also you know that slow speeds have dividet to two different modes, scan mode and "normal" mode. (scan mode is default).
Btw, where from you buy "old" scope? Why you do not contact to seller for update?
It is maybe very frustrating to Owon that there are sellers who do not care anything and then lot scope owners need direct help from factory. I think soon Owon need make some rules for dealers - who is certified dealer and who is not. It can not be long time so that sellers sell without any customer care selling instruments just like milk bottles, only get money and then all customer care need come directly from Owon.
Sellers need do customer care work also, before and after sales. Lot of sellers do not care anything but get money - easy money. Then we see lot of scope owners who hang around internet finding who can help me...who can help me.. this is "bad sellers problem" and also these bad sellers push prices down - maybe they are brainless.
There are also sellers who care and give after sales customer care service, but they are not maybe cheapest ones.
If you just get your scope from seller and it is very old FW - why seller did not update it?
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Well, my main interest was if there is a known bug with Owon's SDS line regarding USB sticks in general (i.e. support only for small sector sizes or whatever). Since to me it looks as it couldn't store files >8kb on my larger (>8GB) USB drives.
Regarding my "old" scope: I guess the 8102 sells much less frequent than the 7102, so it's not too surprising that it doesn't have the newest firmware. Please also take into account that the version numbers between 7102 and 8102 seem to differ since the SOP of the 8102 was later AFAIK. E.g. at the time v2.1.1 was out for the 7102, I understand the 8102's firmware was at revision v1.0.1. Let's see what revision the newest firmware will have (if I get it), but I would guess it's something like 1.0.2 or 1.1.0.
I also don't really expect a seller to open every box and reprogram the newest firmware. This is not common for any consumer product, so why should it be different for a low cost scope? Besides people would complain about opened boxes. IMHO You could only expect that kind of service when buying a >10k€ scope directly from LeCroy or similar.
I'd gladly update the firmware if Owon had a public download site, but as they don't, I have to bother them. So this clearly caused by Owons strange strategy of giving you updates only if you demand them and not the seller's fault. So maybe bothering puts them back on the right trail.
Besides, I also contacted the seller (which claims to be the only official Owon seller in my country), but they didn't react yet (as didn't Owon). I sure hope though that one of them will finally responds and provide me with a newer firmware revision...
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Since I don't want to mess the "good choice for first oscilloscope" thread, I'll answer this here:
Local authorized Owon dealer is good place to ask update. Everyone have buy it from some place. Very simple, ask seller. And more simple, before buy, look littlebit wherefrom buy. It is not so bad if buyer also use his brains when select wherefrom buy.
As mentioned before, I bought from the only official Owon dealer in my country and neither did they respond to my mail nor did Owon up to now. To be fair, I have to mention that I contacted them last Wednesday, so it's not like I already waited for weeks, but they could have answered on Thursday and Friday and didn't. Furthermore I have to mention though that the Owon customer service answered another of my mails some time ago, but they needed a week or so, the answer was in pretty bad English and it answered only half of my questions. As this is more or less the industry standard, I wouldn't go so far to say that the customer service is completely absent, but it's not really perfect either.
So neither do they react quickly nor is it good practice to keep SW updates from the customer. Heck, large comanies as Agilent and LeCroy encourage you to update the firmware even for their highend equipment, as do smaller companies as Rigol, so why can't Owon?
Owon customer support and customer care is one of most good what I know. Always nearly immediate answer and you can fax, email, phone call etc.
Then you obviously never tried the service of LeCroy or even Agilent. They usually react within hours.
There is no any reason for public open dowload place for FW updates or repair patches.
Yes there is. If they release buggy software, they should also give you the updates without letting you beg for it.
Buy from grey ebay seller who sell teddybears and oscilloscopes and parfumes... you really think it is clever to buy. Then waiting customer care.
Dunno how often I need to repeat that I bought from the only official Owon dealer in my country. And no, they don't sell anything but measurement equipment. So why do you keep insisting it was my fault that Owon delivers buggy firmware and neither Owon nor the dealer offered me an update up to now? It's not like I already gave up. But a good customer service is something else.
Still, even taking into account the existing bugs and the problems to get a firmware update, I don't regret that I bought the SDS8102. I don't think you can get a much better scope for the money at this moment and there's the chance that it can be patched to 200 or even 300MHz in the near future. But even at 100Mhz, the great screen and the 10M record length IMHO make it a clear winner.
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Another thing just for the sake of completeness. At the begin of this thread, marmad said that ...
It takes exactly 4 minutes to save the full 10Mpts to the USB hosted device (during which, of course, the scope is doing nothing else).
This doesn't seem to be true for my 8102, and thus it shouldn't be true for the 7102 either. The saving of one 10M ch needs about 27seconds on a relatively lowish class 4 microSHDC (in an USB adapter). The created file is 9766KB (or 10000069 bytes) in size, so the transfer rate is about 361 kByte/s or about 2.83 MBit/s.
Since a class 4 card should reach a minimum of 32Mbit/s when writing, the card is obviously not the limiting facor. So yes, saving to an USB stick is very slow and doesn't even nearly reach the limits of USB1.0, but it's still about 8 times faster than stated by marmad.
BTW: it's a bit weak that you can't save both channels at the same time. Also the "copy" button always saves the waveform, even if you defined saving to bitmap in the "save" menu.
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In this case I did not at all compare to Agilent or Tektronix. LeCrou have never touch.
I have repaired Agilent and Tektronix equipments long time and I know something about they service (but mainly only local).
Well... today they have _some_ updates downloadable. Still I hope get some updated FW to my nice spectrum... oh well but but product is designed to be obsolete... so I can not get. I need copy it from some other. I know Agilent have it... but no one there want find it and give it.
Chinese companies are just started learning how to arrange customer care and after sales services.
They are just started this long travel for learn how to make better.
But what I mean, Owon is good also for customer care if look many Chinese factories.
I have try example Rigol. No any answer. Same Atten (Siglent), try to get UNI-T FW update...
I have seen timetable how Owon answer. I know there is also language problems and also, some workers are more loosy than some others so quality of answers may vary. I think they marine radar customer service is better.. maybe.
Example short time a go China have several days holiday. Now it take some time to work with this queye of emails and faxes.
If I try Agilent answer in Christnmas... maybe I need also wait some more hours..
After soon (some days) I know if SDS8102 or 8202 have factory updated FW.
In this price class 7102, 8102, 8202
they are amazing good scopes. Not so much features in FW but, quality of singnal sampling is good. Display is special good. (and if someone really want it can also make more bright becouse backlight is driven well under specs)
Full speed 10M capture memory is really good. If look slower t/div it give really big advantage in sampling speed if compare what ever this price class scopes or even much more expensive Agilents.
Turn Agilent expensive 100k memory scope to 1ms/div and look what is realtime samplerate, it is like bicycle compared to phantom.
Btw, my language is bad. I did not mean at all you. In most things what I have write I mean universally peoples who buy oscilloscopes or other things from some sellers around of world. There need be careful. There need use braind and not only paypal pay now button. Example in China, there are lot of cultural things... buyer is responsible... not seller (caricatured). Seller is clever if he can sell bad things with good price... buyer is just stupid as pawn if he buy this. Buer need shame... seller can be broud.
If people buy bad things, this is not manufacturer... people need go to mirror and ask who is guilty. There is common that if someone sell something it need always think (or suspect) that all is lie. You buy chicken. Ask they first empty stomach... there may be cup of rocks... if you buy electric wire... ask seller to show that inside really is copper wire... not only plastic tube... if you buy ten eggs, do not give seller select them... and ask you break one random.. so you can see that they are real chicken eggs and not human made lie eggs.. these old things are still affecting... in global world and buying without posibility to real look, touch and test this old system do not work.
So, many Chinese companies need do extremely hard work for learning how to get peoples trust. If there is 1000 satisfied customer they do not make noise over internet every corner... if there is one unsatisfied he may do big big noise what are readable in each mud hut anywhere in the world.
I can ask: Why Hantek have need publishe "many" updates and repair patches inside less than one year? Then sharing this bullshit... this we want? Public bullshit sharing. If Hantek do not immediately stop this stupidity they really can loose all!
Please hantek, do buglist, do changelog and start do work in good order. I think these young couple of boys there in Hantek need really someone watch over them. Give commands what to do how to do and when to do. In good order and with tight programming rules. Do not any change before it is a proofed it need do, tested before implement, do final tests... carefullu and keep good test diary. This game need whistle break now - or vthen newer.
I hope no one try push Owon to this road. What is right road, it need carefully design. Today this system (updates, repairs, customer care, after sales services etc) is not mature, but they still have done amazing good work and all signs show that they also learn and they are interest to learn to be better.
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Sure, I agree that the Owon's firmware - despite of the USB saving issues - is very stable. If I believe marmad's video reviews (and I tend to do so), Owon's firmware is even much more mature than that of Rigol and Hantek/Tekway.
Up to now, the SDS never crashed on me, always showed plausible waveforms and I didn't find any major issue apart from the USB saving. So of course I favor a stable firmware update now and then over a beta patch every 2nd week were each patch causes new issues.
Also, honestly I didn't expect the firmware to be completely bug free. Indeed out 8k€ Agilents in the job crash now and then and e.g. suddenly don't respond to the vertical position knob any more. Or they switch to AC mode (displayed via LED) though they claim (in the menu) they are in DC mode. Even the 14k€ LeCroy crashes in some (admittedly high endish) analyzing menus and after the last firmware update, the front panel was dead and I had to fiddle around in the system registry to make it work again.
Still, I would really appreciate if there was a public firmware download with a good history on Owon's web site. There is nothing wrong with making mistakes. They just need to be documented and fixed. Not offering public downloads and change history might have other reasons (like trying to avoid fw hacking), but usually it stems from the idea that making bugs is something to be ashamed of and therefore trying to conceal it. This would be a pretty bad attitude from a quality management point of view.
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Thats better than my DSO-X 3000 which never works as it should. (If i even manage to get it to boot)
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I've been thinking of buying this scope for a while, but I can't find a proper place to buy it. Most places I find seems dodgy and yeah, I'd really like a Owon Certified dealer. Does anyone know good dealer that I can trust?
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You could ask Owon (http://www.owon.com.cn/eng/contact.asp) directly for a dealer in Norway.
If there isn't one, you could import it from another EU country.
E.g. www.batronix.com (http://www.batronix.com) has a pretty good reputation, though they are no official dealer AFAIK.
In the UK, Owon has an own online shop: http://shop.owon.co.uk/ (http://shop.owon.co.uk/)
There is also the guy from Finland in this forum: https://www.eevblog.com/forum/index.php?topic=4597.0 (https://www.eevblog.com/forum/index.php?topic=4597.0)
In the Netherlands, you could try e.g. http://www.eleshop.nl/nieuwe-serie-owon-sds7102-p-480.html (http://www.eleshop.nl/nieuwe-serie-owon-sds7102-p-480.html)
Or in Germany there's e.g. this dealer: http://messgeraete-chemnitz.de/tisch-oszilloskope/index-2.html (http://messgeraete-chemnitz.de/tisch-oszilloskope/index-2.html)
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Up to now, the SDS never crashed on me
as you have SDS8102, try this one:
setup you DSO to whatever settings (default or something specific, didn't matter)
open FFT
do STOP
do Autosetup
and you scope should now "play guitar together with Kurt Cobain"
It was always killing SDS7102 (no matter what firmware), would be interessting to hear what on other models.
EDIT: to play fair, Owon knows this bug since maybe two weeks max, so be patient if your scope have same issue.
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Ok, nice freeze :)
Honestly I didn't really test the FFT much as this is a feature I never really need. And Autoset is nothing I normally use either.
Also note that I have a v1.0 firmware though I suspect the 8102 firmware numbering differs from the 7102. But it's a pretty old version anyway...
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There is nothing wrong with making mistakes. They just need to be documented and fixed. Not offering public downloads and change history might have other reasons (like trying to avoid fw hacking), but usually it stems from the idea that making bugs is something to be ashamed of and therefore trying to conceal it.
This is also partially cultural difference. This is one thing Chinese manufacturers need learn. But it can not go so that Chinese learn and we do nothing. Also we need accept and adapt to cultural differencies. They need littlebit more open mind and no need ashame if some bug or wrong design. We need lean how to do negotiations so that also they do not feel loose faces. If people talk to chinese same as he talk to western manufacturer he loose his game. Best what we can do is co-work style to solve problems together. If someone go just like showing with finger directly with big noise "you have make wrong" this method do not work.
But one main problem is nearly as paranoic afraid of copycats. This problem they have develop themselves.
Btw. if peoples want hackable scopes, why not do this? (some hidden design so that it seems like factory try secure it not hackable but still keep some door open.. . and peoples are interest. (I littlebit think that someone have find this idea...what happend if Rigols change two bits... maybe selling decay becouse not anymore hackable, and they know what are these bits, hack "door" can close without any money.)
Revision history / Ghangelog and even buglog.
This I hope all do who make things with upgradeable FW.
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BTW: it's a bit weak that you can't save both channels at the same time. Also the "copy" button always saves the waveform, even if you defined saving to bitmap in the "save" menu.
Both channels at same time. This is nice if have but it is also littlebit difficult. (not exactly difficult but they need store separatelly. One after one to the USB memory. They can not merge if do not change "everything".
File structure is 69 bytes header what include all information about scope and settings, after then come data what include only ADC 8 bit signed integers. If do both channels store it need (with this datastructure) only store one whole channel file after one. This can of course do automatic if add this feature to FW. It last twice time and scope need keep frozen whole this time. This feature, store both, have not implemented and user need himself first store other and then store other. If want do one file, well all need do new. Both channels may have different settings, voltage and shift.
I hope they change "copy" button function. It need follow what user have selected in "save" menu. If I have selected "picture" then it save picture. If I have selected wave it then save this captured ADC data. This make scope more fast to use becouse need only push one button for save wave or picture as user have preselected in save menu.
Some this kind of development (many small things) is nice if they can do for FW after collected some good amount of users opinions.
I'm very happy if some manufacturer do so that just before some new model is ready to markets they collect some independent professionals for make useabilitys tests, then collect opinions and make final version.
Also some info on the screen need name different.
Where from come example M: what it means... yes after 5 minutes you learn and remember it is time/div. In some cases chinese language is more nice, it is more powerful if look how much information short phrase can contain. Information density is (mostly) much higher than western alphabetical languages where all info is in serial gueye. And voltage is V, mV, not v, mv.
But it is nice that they can write western alphabeticals.
Try turn you scope menu language to chinese. ;) maybe it is more nice.
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Ok, the good news is that Owon finally responded. The bad news is that I don't get an update yet...
Dear Sir,
Thanks for your support to OWON products.
We'll give u a upgrade software to solve your problem but needs some time.
After finishing, we'll send to u.
And one pretty bad thing that I just noticed and that I wasn't really aware of when selecting the 8102: the 2GS/s (1ch) and 1GS/s (2ch) sampling frequency is only possible for record lengths of 10k or less. With more than 10k record length, the sample frequency is automatically reduced to 1GS/s (1ch) and 500MS/s (2ch).
So I guess if you want to use the large record lengths, the 8102 is effectively the same as a 7102.
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And one pretty bad thing that I just noticed and that I wasn't really aware of when selecting the 8102: the 2GS/s (1ch) and 1GS/s (2ch) sampling frequency is only possible for record lengths of 10k or less. With more than 10k record length, the sample frequency is automatically reduced to 1GS/s (1ch) and 500MS/s (2ch).
So I guess if you want to use the large record lengths, the 8102 is effectively the same as a 7102.
Is that actually confirmed anywhere in the literature or documentation for the 8102? That doesn't seem right. Make sure you confirm with another owner that they have the same issue (maybe bertchai?).
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Well, I was not aware of this limitation, as IMHO it's not mentioned in either the technical specs nor the manual.
Indeed Owon advertises the SDS like this on their site: "10M record length with highest 3.2GS/s sample rate".
Now I guess you'd need to read this as "up to 10M record length" and "up to 3.2GS/s" sample rate and not as "10M record length at 3.2GS/s".
On a 2nd thought, that limitation makes sense if you consider that the common understanding ist that all SDS models share the same hardware (apart from the ADC). So they also share the same memory bandwidth. Quite obviously you'd need twice the bandwidth for a 2GS/s sample rate. So probably the Owon is limited to the FPGA internal block RAM for any sample rate >1GS/s.
Of course everybody with a 8102 or even 8202 is invited to confirm this limitation. I also asked the Owon customer service about it, but based on my experience, it will take them a few days to answer. And honestly I can't imagine that this is a firmware bug.
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On a 2nd thought, that limitation makes sense if you consider that the common understanding ist that all SDS models share the same hardware (apart from the ADC). So they also share the same memory bandwidth. Quite obviously you'd need twice the bandwidth for a 2GS/s sample rate. So probably the Owon is limited to the FPGA internal block RAM for any sample rate >1GS/s.
Yes, I suppose it makes technical sense, given the hardware - but it's something that should be addressed in the specs or manual. To me, that would be grounds for returning the scope for a refund (if that's what you wanted to do) - since it's a fairly big thing. OTOH, perhaps you might consider swapping down to a 7102 - it costs quite a bit less for just the loss of the higher sample rate at 1K and 10K.
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I tried to get some information regarding the USB protocol specifications via the Owon customer support. As I am not a native speaker my English might not be the best, but at least people understand what I am writing. Unfortunately the person in the customer support does not seem to understand what I want:
Dear Grace,
sorry, for not explaining myself clearly. I do not ask for a Linux or
Mac Version of the software, but for the specifications of the data
protocol used for communication with the oscilloscope. These
specifications are independent of the operating system. We are running
several research projects using Linux machines and it would be very
helpful if I could read data from your oscilloscopes with these
machines. If you could provide me with the USB protocol specifications,
I could develop a driver that enables me to read data from your
oscilloscopes using our Linux machines.
Please tell me, if you can provide me with the data protocol
specifications or not.
Kind regards,
XXXX
Am Montag, den 17.10.2011, 16:50 +0800 schrieb service:
> ?
> Hello XXXX,
> It can only support WINDOWS.
>
>
> Best Regards,
> Grace
> OWON Service Team
> ------------------------------------
> Xiamen Lilliput Technology Co., Ltd.
> Website: www.owon.com.cn (http://www.owon.com.cn)
> Mail address: service@owon.com.cn
> Tel: +86 592 2575666
> Fax: +86 592 2575669
>
>
>
> ???? XXXX
> ????? 2011-10-17 15:08:13
> ???? service
> ???
> ??? Re: SDS series USB protocol specifications
>
> Dear Grace,
> as I have mentioned in my previous eMail, I am not asking for the
> current version of the Windows software you offer, but for the current
> specifications of the USB protocol, so that it is possible to get data
> from the scope using also e.g. MacOS or Linux. I have found
> specifications for older Owon scopes here:
>
> http://sourceforge.net/projects/owondriver/files/ (http://sourceforge.net/projects/owondriver/files/)
>
> Unfortunatly, these specifications do not seem to be up-to-date. I am
> therefore kindly asking, if you could provide me with an up-to-date
> version of the USB protocol specifications.
>
> Kind regards,
> XXXX
>
>
> Am Montag, den 17.10.2011, 08:52 +0800 schrieb service:
> > ?
> > Dear Sir,
> > Thanks for your support to OWON products.
> > The newest software can be found on our websit.
> > FYR:
> > http://owon.com.cn/eng/technology.asp?types=SDS (http://owon.com.cn/eng/technology.asp?types=SDS)
> >
> > Hope these can help you and still have any problem,pls let us know.
> >
> >
> > Best Regards,
> > Grace
> > OWON Service Team
> > ------------------------------------
> > Xiamen Lilliput Technology Co., Ltd.
> > Website: www.owon.com.cn (http://www.owon.com.cn)
> > Mail address: service@owon.com.cn
> > Tel: +86 592 2575666
> > Fax: +86 592 2575669
> >
> >
> >
> > ???? XXXX
> > ????? 2011-10-16 02:26:07
> > ???? service
> > ???
> > ??? SDS series USB protocol specifications
> >
> > Dear Madam or Sir,
> > I have recently purchased an SDS7102 oscilloscope. I would certainly
> > like to run the Windows software that was provided with the scope.
> > Unfortunately, the PC I use for measurement runs Linux for different
> > reasons. I found some specifications regarding the USB protocol for
> > communication with older versions of Owon scopes (PDS series) and tried
> > to use these specifications to implement a simple driver in Python.
> > Obviously the specifications seem to have changed for the SDS series, as
> > bulk-reading from the scope times out when sending the start command. I
> > guess, that it might be the endpoints or the start command that have
> > changed. Anyway, I kindly ask, if you could provide me with an updated
> > version of the USB protocol specifications, so that I could develop a
> > linux driver for SDS series oscilloscopes.
> >
> > Kind regards,
> > XXXX
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It looks like the Linux driver is a private project of Michael Murphy, and the project seems pretty dead - no code was ever committed to the svn repository. Probably nothing to do whatsoever with Owon, which means that support will be no help.
You could try contacting Michael: http://sourceforge.net/users/mgmurphy (http://sourceforge.net/users/mgmurphy)
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OTOH, perhaps you might consider swapping down to a 7102 - it costs quite a bit less for just the loss of the higher sample rate at 1K and 10K.
I'm trying to get a definite response first, but indeed I'm toying with the idea to downgrade. Indeed I could send my 8102 back without any reason for 14 days, so I have at least one week left to decide.
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It looks like the Linux driver is a private project of Michael Murphy, and the project seems pretty dead -
I see three releases. One from May of this year. Dead looks different to me.
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I tried to get some information regarding the USB protocol specifications via the Owon customer support. As I am not a native speaker my English might not be the best, but at least people understand what I am writing. Unfortunately the person in the customer support does not seem to understand what I want:
She understands you very well. But because she can't give you what you want she pretends to not understand what you want. In short, the answer is "No, we won't give you the protocol.". If you continue to try to make your point she will just stop answering
If you are in the EU, you could consider making use of the EU directive which allows a limited amount of reverse engineering for the sake of interoperability.
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Well, the document ("OWON Oscilloscope PC Guidance Manual 1.1") in the sourceforge archive seems to speak a different language. There is no hint that it could be created by anybody else but Owon and its title (though in pretty bad English) obviously states that it's meant to support Open Source development: "Communication Protocols of USB and Introduction of data format, open source for the third party".
Besides, it would be dumb to not support Open Source development. The Windows application is pretty bad and they should be glad if anybody would volunteer to support the Owon scopes with anything better.
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The Windows application is pretty bad and they should be glad if anybody would volunteer to support the Owon scopes with anything better.
the Windows app is written in java, take a java decompiler, spend 2hrs (with decompiler and USB sniffer)
and you will know everything you wish to know about the protocol.
Even if you spend a day, it will be faster than waiting for an answer from a dumb manufacturer.
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It always helps if you quote the same you address. As you obviously address Chinakoch, it would have made more sense to quote him than to quote me.
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This is very clear:
http://ee07m060.wordpress.com/2010/07/14/owon-release-official-specifications/ (http://ee07m060.wordpress.com/2010/07/14/owon-release-official-specifications/)
Problem is now more only that what to talk, how to talk and with who.
It is clear that there is "phone answer machines" also in Owon (letter answering "machines".
If someone is really seriously developing this kind of things for public use I can easy look between lines that Owon is happy if someone want do this.
But it need serious work and not things what make any harm to Owon brand... if there is win-win I thing Owon smile kindly to you and give also some help. But you need find also right person in Lilliput group. Person who understand that it is good for all parties and also person who have enough deep knowledge - and person who can put some his working resources to this.
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Well, the document ("OWON Oscilloscope PC Guidance Manual 1.1") in the sourceforge archive seems to speak a different language.
This is the past. Just because someone at some time in the past released that document doesn't mean they will do it now.
Besides, it would be dumb to not support Open Source development.
First, companies do dumb things all the time. In fact, probably 80% of what large companies do is dumb. Chines companies are maybe up to 95% dumbness. So dumb isn't an argument.
Second, why should it be good to spend time and effort to make a tiny minority happy? Until now they manage to sell the SDS oscilloscopes without such a specification, and the majority of those buying such a low-end oscilloscope anyhow couldn't care less about the PC interface.
The Windows application is pretty bad
Exactly because they figured only a tiny minority really wants to use the interface. And they just need to have some software to tick of an item on the requirements list.
and they should be glad if anybody would volunteer to support the Owon scopes with anything better.
And if they don't see the point? If you feel it is your job as a customer to enlight a company, you are welcome to try. The reality is companies don't want to be enlightened.
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It looks like the Linux driver is a private project of Michael Murphy, and the project seems pretty dead -
I see three releases. One from May of this year. Dead looks different to me.
May of last year you mean. Nothing since.
It looks like Michael got the drivers working for his model of oscilloscopes, along with a few other models owned by other he was in contact with, and left it at that.
There is no sign that this is an ongoing driver development project. No files were ever committed to the svn, so it does not look like this was intended as a community opensource project. Just one guy using Sourceforge to publish his code.
It appears Michael did get some data from Owon, so that is why it is worth contacting him.
His email address is in his driver files.
Richard
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Of course everybody with a 8102 or even 8202 is invited to confirm this limitation. I also asked the Owon customer service about it, but based on my experience, it will take them a few days to answer. And honestly I can't imagine that this is a firmware bug.
Shortly: (I'm now extremely busy so I can not make more tests)
With SDS8202 VGA, (version 1.1.1) I can confirm that 2GSa/s is limited only for 1k and 10k capture memory lenght.
It is not bug, it is feature. But I do not know how they do it becouse first mutual feel is that ADC do not change clock frequency. (not yet confirmed by measurements directly in the acquisition circuit)
Later I do more lab tests with 8102 and 8202.
But fast overall look, signal sampling quality looks amazing good in this price class, pity it do not have direct 50 ohm (HF impedance) inputs, if it have it is HF-RF peoples's scope..
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I kinda assumed that this is a bandwidth limitation.
BTW: if you have access to a 8102, could you tell me to firmware version it has?
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V 2.1.1
Serial prefix SDS81021128
BTW: it is also VGA version.
-
They have quite a lot of different firmware versions out for a company that claims that the product is mature. Or they use a strange version system.
-
What are all version numbers what you know or have seen somewhere for SDS8102?
I do not know if VGA optin scope and not VGA have different FW. (maybe have)
Please do test:
CH1 or 2 alone used. 10k mem, fast speed (example 1 or 2ns/div.) look stable triggered good quality signal. Use normal capture (not average). Note how it trig and where is trig point. It need be nearly where signal cross trig level.
Turn mem to 100k or 1M. What happend if look where is real trigger point. (trigger time mark related to point where is real trigpoint. Also watch if trigger stability change and how much it add triggerjitter.
I did not have enough time to do deeper test but only I notice that I'm not as satisfied as with 7102
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Hm, the time between crossing the trigger threshold and the actual trigger seems to vary indeed with the record length, but this also seems to depend on the current timebase (time/div).
Unfortunately, I currently don't have any means to create really strong edges, so going down to 1 or 2ns/div to check the trigger condition is not really feasible.
E.g. at 50ns/div, the signal crosses the trigger threshold about 50ns before the displayed trigger event when using 1k record length. When increasing the record length, this distance decreases to less than 10ns.
Then again, when I repeat the same test at 10ns/div, this behavior is not reproducible and the signal crossing the trigger level will always be around 50ns before the displayed trigger, no matter what record length.
In both cases, there is a certain jitter visible. Then again, my test signal is not very sharp edged and with some noise added, this is to be expected.
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I just bought a SDS7102 directly from OWON, I paid $500 USD total to be shipped to
USA, I think I bought the brand new model, which includes a VGA out, a LAN port, and also
a 8Ah Li-Polymer battery. The firmware version is 2.2.1, I am still testing the scope,
more detail will follow.
The reason I bought from them is I want to know if OWON has the model with LAN port,
so I can use the scope remotely. I saw many people here said there was no such model.
But several websites do show SDS7102 with LAN. I asked many retailers and ebay sellers,
all replied SDS7102 only has two modes: with VGA and without VGA.
So I contacted OWON to clarify this issue, and later a lady replied from fiona@owonchina.com,
told me they can ship directly to me. Total is $500 include DHL express shipping.
But I have to wire transfer $500 to their HSBC bank account.
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Yuk, that Owon front panel looks cheesy! It looks like some kind of Fisher-Price toy :-\
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I recall marmad said the same during his review, but its what's inside that counts.
Until marmad's review, the Owon had no real following on eevblog, at least, and made it one of the better low end scopes to consider. For comparison, there is an Atten scope in this performance range that did not do well with a performance review.
Yuk, that Owon front panel looks cheesy! It looks like some kind of Fisher-Price toy :-\
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SDS7102 with LAN
hey, i have a nice gift for you, see attached.
Use both of them and shot some pictures of the PCB and LAN :)
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SDS8202 samplerates in fast horizontal speed area 1ns - 50ms/div
Slow speed horizontal speed area 100ms - 100s/div not included here.
(also notice that low speeds are divided two different modes. As normal capture mode and scan mode(default))
Of course this table is valid to both 2Gs/s models. SDS8102 and SDS8202.
Difference with these models are only analog BW.
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these values are really bad ... in deeper mem no difference to SDS7102,
not worth to pay extra money as the SDS7102 bw is already 140MHz
these values are not bad - Rigol CA have always max. 2 x 5k while on 2GSs,
Owon SDS8xxx max. 2 x 10k - that's twice the Rigol depth plus a 10M bonus when sampling
with 1GSs. Additionaly higher bw than on Rigol CA, not much but ask your wife - 5cm more is a lot
take the one you like .... actually i'm not surprised that Owon (once again) lying about such important feature,
but well, we know that other manufacturers are not better. I hope some day ppl will learn the difference
between "up to" and "of", because it matter.
@rf-loop,
when you have time please measure bw of SDS8202, i think it will be something like 250MHz
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@rf-loop,
when you have time please measure bw of SDS8202, i think it will be something like 250MHz
Yes it is nearly.
But as we well know, more and more high freuency and impedance matching go more difficult.
0 - 100MHz with this kind of input is not big problem to match with 50 ohm terminator connected to input.
(if take signal directly from 50 ohm source via 50 ohm cable.) Of course problem start littlebit but not bad.
100 - 200 MHz and problem is more bad. Over 200MHz it is so bad that what we test.. our signal road or oscilloscope itself.
It is pity that this kind of scope do not have 50ohm impedance inputs. (I do not mean that terminator resistance is inside scope. I mean impedance 50ohm for this whole frequency area.
If look only one example. 15pF reactance at 200MHz frequency is around 53ohm. If forget all other things in practice there is 50ohm terminator and parallel with it 53 ohm reactance. Simply: I can not simply measue oscilloscope itself frequency response becouse I have not well matched feedline to oscilloscope. If I do it, I measure whole system response only. With 100MHz it is also there but error is "acceptable".
With extremely bad matching, 50ohm terminator connected to oscilloscope input (1M, 15pF +-5pF) I can see that scope show -3dB point around > 230MHz. (this is not scope response, it is system response what is more bad than scope itself... and here around >200MHz this error in measurement come really markable)
-----------------
This is not for Owon. This is for ALL manufacturers today. And littlebit more to Asian manufacturers.
They must not hide specifications. They can sell one machine. People read specs and ads and then he have "waiting value" that it works as he have dreamed after he have read machine introduction/ad.
Now if it do not work as he have dreamed it is big disappoint and around of world or with himeself he talk how bad it is - just becouse he was dispappointed. Maybe machine still work and is just ok to what he need but becouse he was dispappointed his feel is "this machine is peace of bullshit". Maybe he feel fooled and also this Company is bad lyer in his mind.
Please peoples, do you homeworks. Study how to read datasheets, if it is cpomponent, multimeter or oscilloscope and go to look mirror. First study basic low level things how stuffs work, then read lot of material how professionals teach how to read datasheets in professional use for designing and how important are also application notes and also all these small note texts just as in insurance deal papers.
After all you still read ads and specs, nice pictures and so on. manufacturers do lot of introductions and maybe also copmare they machines to others. These are many times so biased and they find most nice way to compare so that they own looks ten times better. Well known case is this HP - Tektronix game (specially with oscilloscopes)
(look specially what they do not tell... do not come blind after they talk what they want talk - watch carefully and deeply what they do not tell. This is sometimes maybe most important thing to find)
Try to find Agilent papers what tell exactly memory depth and samplerate it use with different settings (you can not find) and what it can or can not use. (example after you read this wfrms/s bullshit or half truth. yes they do not not exactly lie but...
I think some manufacturer may win who is honest and who do not give peoples feel disappointed and fooled.
Who is first who understand this -- and also... do it in real worlkd!
I want be one small small part of this system what teach this to Chinese. They can win in end if they want. But what they need start. They need start learn how to be more open. How to be honest. This old culture of clever smart seller who can sell chickens with heavy rocks and stupid buyer need stop. Everyone can be smart seller and fool someone to buy and win his money - but he can do it only once with this buyer. World is now different. It works in old world where you move 5 kilometers and then you are agen new unknown. (or in big city it need 500 meter.)
With test equipments this may win who publishe most accurate and deep specifications and also real specifications. Not copypaste specifications from other manufacturers.
It was how Tektronix win tens of years example world of oscilloscopes.
There was even full detailed description and theory about inside circuits and full and updated schematics and service manuals etc.
No one copy these so that it is bad for Tektronix. No one. Why?
Owon grow in good tree... it is like raw apple. If they want, they can be better.
They need do some small things and one of these things are good and hinest specifications where people can exactly see what he buy... then he is not disappointed with his own developed dreams becouse there are not enough facts. (this is natural for peoples mind and it can also work opposite, you can hate something just becouse lack of knowledge. But you can also hate something if this something have destroy your own itself developed dream what was possible becouse lack of information)
After disappointed or feel like fooled.. peoples write they opinion. Many of these opinions may very easy destroy one name... or seriouslu damage it. There are thousends of peoples who have not write any opinions. Also in this unsocial media if peole is angry and disappointed he open more frequently his mouth as this kind off people who feel neutral or satisfied.
So, what I hope.
I hope some Chinese manufacturer start develop themselves. Owon is one good candidate.
Littlebit quality and reliability developing, littlebit more thinking for UI useability.
And accurate information about features and specifications.
Do not afraid and ashame specs details as they are. Truth can not really hide. If some detail is not so good please tell it also. If you hit information you give, with lack of information, that people can develop some "dream" that it have this or that feature. Then if he buy and there is not what he have dreamed... you maybe have get his money -- "fished and get his money" yes you are smaryt and clever Chinese business you can fish money from "stupid" poor educated buyers.
But if he is not in your boat and he is disappointed only becouse lack of information or even you have littlebit lie or as white lie information....
He may have to pour your fishing boat if he is not in the same boat with you.
So, if Owon or who ever manufacturer want win. Start develop design quality, quality control, start be more open mind and stop this shy and hide with specs. Real honest specs to table - please, and if do it right way - you win and customers win and both can smile.
Owon is not bad, it is one of most good oscilloscope in this price class. It give not se many dingle dongle features but it is good DSO.
Today with this FW and/or HW this SDS series maximum samplerate with more than 10k/channel memory is 1Gs/s.
If we talk SDS7102 alone it have deep memory with full maximum samplerate 1Gs/s with one channel or 500Ms/s with two channel in use. This capture memory is selectable from 1k to 10Mpoints. Both channels have max 10M capture memory (not divided memory
SDS8102 and 8202 have not deep memory with full 2Gs/s. Maximum to deep memory is 1Gs/s with single channel or 500Ms/s if two channel in use.
With 2Gs/s in single channel use and 1Gs/s with two channel use there is 1k and 10k capture memory.
(in FW it is nice that if use fast horizontal speed and it use 2Gs/s then if you select more memory you can do it. It drops samplerate. If you agen select 1 or 10k it return this 2Gs/s. And becouse it always show samplerate on the display you always know what it is doing. (exept with low speed area if scan mode is used... there display show (this is bug) totally wrong samplerate, if slow speed mode (100ms - 100s/div) use normal or singleshot mode (not scan mode) it diplay right samplerate.
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@tinhead
as you ask 8202 freq response. Now measured but note what I before write about matching.
With one thru in 50ohm Tektronix terminator:
Reference freq 1MHz
Scope set to 50mV div, dc. One channel in use.
Signal level so that it is 300mV p-p with 1MHz. (6 div on scope display)
-3dB point: 240 MHz
-6dB point: 306 MHz
same test with SDS8102
-3dB point: 126 MHz
-6dB point: 240 MHz
same test settings continue with SDS7102
-3dB point: 146 MHz
-6dB point: 280 MHz
(all scopes are littlebit individuals and becouse with this very bad matching this give quite small variations in scope input capacitance (and other things) affect "lot of" to result.
If need working with high frequencies/fast risetimes with scope what have no real 50 ohm impedance input for whole useable frequency area, this need taken into account. it is possible to make better matching but it is nessesary in only some special cases. With this can live but it need know so that understand what is difference between real world and measured world. )
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Little update from my side: while my dealer was neither able to provide me a firmware update nor other clarification up to now as he says his contact person at Owon is ill, he offered me a 100€ refund if I keep my 8102 instead of downgrading to a 7102. Which is kinda fair I think. Then again, let's see how this works out.
As a side note: as usual when I buy something, the prices for both models dropped by 30€ since I bought my Owon there, but yeah well.
Furthermore Owon contacted me today and sent me a (awfully slowish) link to a 85MB download which contained a new version of the oscilloscope SW (2.0.8.1) and a firmware patch tool. Before you ask: the patch seems to be encrypted or signed specifically for my serial number. I guess this proves that the reason for not providing a download link really is the fear that another manufacturer could disassemble and/or clone their firmware. I'm not so sure that this concept really works, as firstly Atten seems to have already cloned the MSO/new PDS line and secondly, there is a public key in the patch folder. If it's used in the decoding process and not just to sign the firmware, decrypting it should not be so complicated.
Anyway: so I followed the update instructions, at the end the tool told me the update was successful, but honestly after rebooting I couldn't see any difference. The scope still refuses to save files >7kb on a 16GB Fat32 stick, while an 8GB stick works. Using Autoset in the FFT setting still crashes the scope. And most importantly, the Utility-About dialog still shows a "v1.0".
So there are two possibilities: either the update failed or the About dialog shows some version number, but not the one of the actual OS. Since the update procedure looked ok to me, I tend to believe there is a bug in the version display or maybe in their (SW) build process. Probably the ABout dialog is stored in one of the text files that tinhead mentioned and that text file is not always updated correctly.
So while I can't see really an improvement in the firmware, the new "Oscilloscope" (windows) SW seems to be able to read the small (7kb) waveform files saved in scan mode now. Apart from that, it's as bad as before. Then again: the fact that I can save working (albeit very small) waveforms in scan mode seems to strengthen the idea that the SW version is really much newer than the About screen suggests. Or should the scope save large (10M) waveforms also in scan mode?
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Since the update procedure looked ok to me, I tend to believe there is a bug in the version display or maybe in their (SW) build process. Probably the ABout dialog is stored in one of the text files that tinhead mentioned and that text file is not always updated correctly.
right, the updates i saw are only application updates (Owon calls it "osc" or "os"), non of the text files are included in update files
(no reason why, maybe they just don't want to increase version numbers to hide the update count? no clue) so you will
not see any version change.
When you would made NAND dump before and after update you would see that some content has been changed.
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Scan mode use very slow samplerate.
Scan mode is just for eyes if you follow some slow things just as paper roll plotter.
If you want full resolution with low speeds.
Do not use Scan mode.
Auto trig swithch scope to scan mode.
Normal and single switch it to normal mode where samplerate is just as info on the screen.
Still they have not repaired this scan mode wrong samplerate memory info on the display info field.
---------
If update process go right:
First update software window show that it transfers data. After it show that update us success... then automatically scope continue booting.
As you see first you turn scope on (update process) scope stops to boot screen. After update process is ok it continue booting itself. If it do not, it have maybe not really updated.
(You write "after reboot"... did you mean that you need reboot unit after update process.. in success update process it boot itself.)
How to update.
Install update soft and install drivers.
Connect scope.
Let it finish all drivers istall.
Do not continue pressing update (right button).
Shut off scope.
Press right button (update go to waiting state)
Start scope. After it see scope it transfer file. (scope is stopped to boot screen in this phase)
After some time scope install update and then it continue booting.
With some mysterious reason update process do not always go ok even if software info success.
---------
If you can please give me link for update package.
(maybe I can look if there is some change in sampling or sampled data handling if my 8102 accept it - I think it accept...it is (AFAIK) not locked to your serial number.
What is 4 digits on your serial... do not tell whole serial.. I mean these marked as YYZZ... example SDS8102YYZZxxx) (this serial part is not also needed for update but I try look what are manufacturing datecodes and versions they have used.
This info please only PM (not public)
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@tinhead: ok thanks for confirmation. The actual update file inside a (renamed) ZIP file called "bundle" is named "os".
Obscuring the firmware revision seems to be a pretty weird strategy though as it makes it hard for the support to actually tell which firmware someone uses.
@rf-loop: indeed the software tells me "Transmit done, wait for machine process..." and then "Rebooting machine. Patching is done!", but then the scope stays in the boot screen.
So maybe the patching actually failed despite of the success message, but I tried it now a dozen time and the behavior is always the same. I even tried different USB ports.
Regarding the patch SW: in the main installation folder, there is a file called "model" which contains the string "osc" and my complete serial number. There also is a file called public.key which contains 16 bytes and which obviously contains a 128bit public key. So I severely doubt that this update will work on another scope. For the other stuff, I'll answer via PM.
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in the main installation folder, there is a file called "model" which contains the string "osc" and my complete serial number. There also is a file called public.key which contains 16 bytes and which obviously contains a 128bit public key. So I severely doubt that this update will work on another scope. For the other stuff, I'll answer via PM.
Ok then it is different what I have for 7102.
File (osc) is 12 bytes and do not include direct serial number (but it include 37 prefix from serial number what is somehow related to product revision... (becouse 28 and 37 have different power supply and maybe other small differencies)
And with same package have updated several scopes. (not serial number locked)
I have sometimes see this happend that scope do not continue booting and still it have updated. But mostly it boots (but take littlebit time)
Some very short time ago they have updated this PC software on the Owon side downloadable. (size have changed but here it is nearly impossible download... <1 - 3kb/s.. so I can not check what version is there now)
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Mine never ever reboots, but always stays in the bootloader. I.e. I can reprogram again and again without turning off/on.
For the other stuff, check your PM.
Besides, by chance I stumbled over some more relabeled Owons:
http://www.peaktech.de/produkte/kategorie/digital-oszilloskope.html (http://www.peaktech.de/produkte/kategorie/digital-oszilloskope.html)
Funny thing is that they changed the front panel sticker to a blueish tone.
http://www.peaktech.de/produktdetails/kategorie/digital-oszilloskope/produkt/peaktech-1255.html?file=tl_files/products/1001%20-%202000/1255_L.jpg (http://www.peaktech.de/produktdetails/kategorie/digital-oszilloskope/produkt/peaktech-1255.html?file=tl_files/products/1001%20-%202000/1255_L.jpg)
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Funny thing is that they changed the front panel sticker to a blueish tone.
http://www.peaktech.de/produktdetails/kategorie/digital-oszilloskope/produkt/peaktech-1255.html?file=tl_files/products/1001%20-%202000/1255_L.jpg (http://www.peaktech.de/produktdetails/kategorie/digital-oszilloskope/produkt/peaktech-1255.html?file=tl_files/products/1001%20-%202000/1255_L.jpg)
Just ugly. Maybe someone can make pink and olive. Just as childrens toy.
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In the meantime I figured out what the problem is with saving files >8kb to my 16GB FAT32 formatted USB stick.
As I already assumed, the problem only occurs for cluster sizes >=8kb, which Windows automatically selects for partitions >8GB.
Under Win7 however the cluster size can be manually adjusted and when adjusting it to 4kB, the 16GB stick works as well.
It seems that the SDS line supports only a 4kb cluster size and fails on every cluster size >= 8kb. Yet I checked it only for
4kb (works) and 8kb (doesn't work). I'm pretty sure though that 16k and 32kb cluster sizes won't work as well.
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Development evolves.
Picture quality is bad after camera jpg etc...
But it tell all what I want tell.
They have developed...
Also slow speeds 100ms - 100s/div deep memory wave save works and now also new PC soft can open these slow speed mode saved .bin files and of course they can also convert to .CSV
(Scan mode maximum samplerate is 2ks/s and memory depth small. (thi is as roll paper plotter) In this mode display info about Mem and speed is wrong. Normal and single shot mode slow speed mode samplerate and memory display is ok.)
Normal and single is full speed with full memory area useable.
Now you can name files. By typing free text.
(V2.2.1)
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Hm, whatever the version of the is that Owon gave me, it doesn't seem to contain any means to edit the file name. Or is there a trick how to get to that menu...
BTW: yesterday I noticed that there is an update for the Zeroplus Logic Analyzer Software which contains a DSO stacking features that also supports the Owon SDS line (the 7102 is named explicitly). Unfortunately, the SW crashes when trying to access the scope. Dunno if this is an 8102 problem again...
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This 2.2.1
Is new 7102 version! Not 8000 series.
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Sure, but in a "normal" SW development process slightly different HW platforms would be either directly supported by the same software or the software would at least share 99% of the source code and would be e.g. configured by compiler switches.
So it's hard to understand that a brand new software for one device lacks features that the software for the other devices has when these features are in the "common" part of the software.
BTW: how do you tell which version the update has? It doesn't seem to be documented in the patch folder and it's not displayed in the scope either.
As another side not I got a confirmation from Owon that
- the firmware version displayed is not updated
- FAT32 cluster sizes >4k are not supported (and they don't seem to be willing to fix it)
- the Autoset function crashes the scope in the FFT view (and they suggest not to use it :) )
Dunno if this was just a mistake, but regarding the FFT they told me that: "... can be solved by upgrade that we'll have a new software for this on our website.". Maybe they are reconsidering their update policy. Would be a good idea indeed.
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With who you have talked?
Owon China?
Yes they have update for PC software on the internet.
This do not solve any problem inside oscilloscope.
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With who you have talked?
Owon China?
Yep.
Yes they have update for PC software on the internet.
This do not solve any problem inside oscilloscope.
This remark was related to the bug in the scope's FFT function. To quote the full sentence:
"pls do not use AUTOSET in FFT mode-----which can be solved by upgrade that we'll have a new software for this on our website."
To me this sounds as if a new scope software which fixes this could be available from their website...
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Owon do not have any FW updates for oscilloscopes for public share on they internet sides.
So this was reason why I ask: Do you really have talked with Owon China?
Ok you have talked with Owon China but now there is some problem. Maybe people who have answered to you did not at all understand you. Also people who answer there as "firs line" is not at all technical people.
-----
UI for scopes are nearly same over SDS models but different models have different HW and so also different FW.
New SDS7102 versions have V2.2.1.
Example marmad who make review did not have this. It was old version.
(Also V2.1.1 may be without small "bugfix patch" or patched IF seller or end user have patched it)
Now this V2.2.1 have still some minor bugs but just as "patced" V2.1.1 two "fatal" bugs have repaired and some other small changes just as this feature for naming files. (also maybe some other things but becouse lack of time I have not enough tested to find others.
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This is not Owon problem:
This is Common problem. I have not seen Rigol, Atten, Hantek, Uni-T, GW etc published any good log about changes.
Years ago Agilent and Tektronix do it. There come even update sheets to schematics.
It seems that most China manufacturers do not understand or some other reason they do not publice any kind of "changelog". If there is different versions it is very important that there is some knowledge about fixed things and added features. I know it is difficult to show that there have been mistakes etc but... still I think it is better to be honest and open. In long run this is win-win if do this.
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Still it is a pretty bad idea to provide people with updates that don't have any kind of version number and keep the version number displayed in the scope not updated as well. This creates all kind of confusion and is counter productive especially for the Owon support since their customers can't even tell them which firmware they really have.
About the update at the website: I'm aware that support people sometimes give wrong answers or give answers that could be misinterpreted. That's why I said "Dunno if this was just a mistake" before mentioning it.
Then again the person who gave the link to the update also wrote this sentence about updates on the website. So you never know. Maybe enough people complained during the last weeks so they decided it makes sense to give up that stupid update policy.
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repair patch do NOT need be different FW version.
Also it is possible that different HW need some repair (FW repair) but still FW version is same.
Maybe they can take this whole version information away from normal end users.
If I am manufacturer I do just this. End user do not need this info. He need only know how to use oscilloscope and what different specs and features it have. Compare old Tek where was not any software things.
I know many 465 versions, really different.
Front panel read. Model 465.
There are some minor specs differencies, whole inside have changed (nearly) maybe also some functions work better.
But what user know. It is model 465 and thats all.
But maybe mister Bill Gates teach us that allways need update and change and thousends of versions and subversions and sub repair versions etc.
I buy Toyota. Model xxxx.
It is bad.
Service do many modifications and changes and even maybe some inside software changes.
What I need know. I need know how it works and thats all. I do not need version numbers etc.
Maybe my Toyota is model xxxx and now it have repair patch... I'm interenting only that I can do my works with it. Thats all what I need know. If there is problem - oh yes there is many - I do not like this and that and something is bad and something is nice.. If it do not work or some fail, I drive it to service. If they change something or upgrade something - I'm interesting that it works and I can do my works. If I can not - maybe I have selected wrong tool (car is tool to me, just as oscilloscope) to my needs.
My spectrum have something like 02.04.04 FW version. There is lot of later versions for same model. Why I need update. No I do not need. It do all what I want and need just as it is. I'm not interest to get new FW. Why, becouse it do all what I need. Yes there are some bugs even it is Rohde&Scwarz.. I know how I can do FW "crash" but why I need do it... I can avoid this procedure with knobs and buttons.
My mind with this update policy is just splitted to two kind of thinking road.
I do not know exactly which is better.
I can not say Owon is stupid becouse they do not put FW's to public downloadable.
I do not know they reasons. So I can not tell they are stupid. Maybe they are very clever ... if I know these all reasons... it is also possible they are just clever. But this I do not know.
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Sorry, but your examples are somewhat misleading.
Of course I don't need to know the SW version of my car's engine control unit because I can't update it on my own anyway. And I don't call support when my car doesn't work, but I bring it to a garage.
In a garage though, they can of course read the HW and SW revision from my ECU. And of course they will do a field upgrade when necessary. So in this case the guy in the garage is the user and it would be as dumb to hide a SW revision from him as it is when Owon is hiding it from me.
Also, of course if a (simple) device is working perfectly, I don't need firmware updates. I don't need fw updates for my mouse or LCD monitor, but many of the technical devices I bought over the last years are either so buggy or leaving out so many functionalities in the first SW revisions, that updates are necessary to make the product usable and worthwhile. There are even system that need updates because the world around them changes after release. E.g. DVD burners need a new media database or revised burn strategies and operating systems etc. need updates to react on security issues.
So the idea of perfectly running complex system is simply not true any more. And as long as my Owon freezes and crashes in certain situations, it's certainly not perfect. And apart from the bugs, there are quite a lot of functionalities that are kinda crippled and could be more or less easily fixed or improved (e.g. saving two channels at once or triggering on both rising and falling edge).
In a nutshell, there is no reasoning that could convince me that this approach of showing dummy fw numbers is not extremely stupid. There is no reason whatsoever to display a wrong (!) firmware version and Owon guys are shooting themselves in the foot with this approach.
Also, there is no reason for not making the firmware update freely available. If they wanted to protect their firmware, they miserably failed by decoding it on the PC before sending it to the scope. By reading the public key from a accordingly named file in the patch folder, they kinda invited hackers to use the patch tool for their own software encrypted with a different private key. So instead of hiding their firmware updates, they should have put a little more thought into their update process.
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Some table about SDS8101 and SDS8202
It can use also for SDS7102 if change there green 2Gs to 1Gs and green 1Gs in 2 channel mode to 500MS/s
I hope there are not so many errors. Some abreviations are also bad but I hope it can understand.
In slow speed modes capturing lenght is always 20div. (so you can calculate samplerate)
Scan mode maximum is 2ksample/s.
Memory selection with Scan mode do not select memory. It select 50s/div if 1k memory selected and if other memory depth selected it selects 200 sample for div.
Slow speed normal and single shot mode works normally with samplerate and memory depth.
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SDS7102 TFT display.
Some times have heard that Owon display should be more bright.
As described before Owon use Chimei-Innolux (aka Innolux) AT080TN52 TFT module.
(same series and quality as Hantek/Tekway)
Contrast ratio min 400 typical 500. (black-white with nominal bacround light )
Luminance min 200 typical 250 cd/m2
These are true if used 180mA bacround light LED's current.
With this current voltage is min 9.3V and typical 9.9V and max 10.5V
Just in new versions Owon seems change this and this is only for littlebit older units.
(example this (very)old version what was as this thread have started)
In some unit I have measured as low as 8.78V if brightness adjust is 100%.
This meand tahat they clearly underdrive these bacround light LED's.
Reason is unknown but, this is quess, maybe they have think battery life.
Battery nominal capacity is ~60Wh. And what here can save is not very meaningfull.
Maybe they have realised that this dim dislpay is really not at all nessessary for battery life and also, user can dim it if need.
Now, if need/want, and specially if some individual oscilloscope is specially dim (becouse components variations inside tolerances) this brightness can change. There is one fixed resistor what need change.
But carefully so that not break limits.
Resistor is R17 (shunt/measure resistor, part of led driver). It is on the "Adapter PCB" what connects Power supply - TFT - Main board - Battery units together and what also have VGA chip for external monitor. R17 is just near backlight LED connector. Variations in other parts and manufacture version this R17 value may be different so it need find carefully what value it need. And, do not adjust this one and only trimmer on this board exept if you have changed TFT screen module or this is new unadjusted "Adapter PCB" as spare part.
TFT Baclight LED's brightness modification.
Measure voltage over TFT baclight LED connector (this is indirect bad method but carefully it can do vith voltage method if do not want go "as high as can" becouse then need use current method) It should be around 9.3V. If it is lower then connect decade box (set to 20 ohm) over R17 with as short cables as possible. Slowly drop box resistance but do NOT accidentally drop under 2 ohm. Follow voltage. Stop point where meter read 9.3V. (measure between connector pins, not GND and connector + terminal.)
As you do measurement and/or modification. Do not short circuit this reistor or open curcuit it with running oscilloscope!
Do not affect any kind of spices in any part of this board as scope is running or starting. It may affect malfunction or permanent defect. (example power up and power down order and timing for TFT is tightly ruled)
Measure R17 resistance and together with box parallel resistance. Change reistor.
In this adjustment you need least 0.1 ohm steps in box, better if have 0.01ohm steps.
Righ R17 value is under 2.00 ohm typically near 1.00 ohm.
If you want go over 9.3V you can but I do not recommend in any case go to over 9.9V becouse this method is wrong (temperature and some other variations affect this voltage).
Right method is current measurement. If want and reliable can, try find R17 value what give LED driving current 180mA. (Display adjusted to 100% brightness in display adjust menu.)
You loose warranty if you go working inside scope. And one time your test wire just accidentally go wrong place inside running scope... you know, sometimes it need so little smoke come out that you can not see it and this is enough and you have 1.8kg electronic recyclable material.
Disclaimer: This is only wink what maybe can do somehow. I'm not responsible about any kind of defect what this modification may affect directly or indirectly. Also all this information may have what ever kind of errors. Alone you are responsible just after you open scope case.
This modification may reduce battery operation some amount.
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Just got my SDS7102 and it seems really great. But I've noticed a couple of things.
When you turn down the backlight (Utility -> Function -> Display -> Backlight), do you hear a buzzing sound below 100%?
Also theres something odd with all the knobs (except volts/div and sec/div knobs). If I hold either of them up or press them down while turning they work oposite of what they should do. For instance, if I turn the trig knob right, the trig voltage should increase, but if hold it down (vertically) the trig voltage increases. This is really annoying because it's not much pressure thats needed before it changes direction. Anynoe else experienced that?
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Just got my SDS7102 and it seems really great. But I've noticed a couple of things.
When you turn down the backlight (Utility -> Function -> Display -> Backlight), do you hear a buzzing sound below 100%?
Can not hear any buzzing sound.
(main frequency for switching constant current driver is 1MHz. For dimming display its 1MHz output is on/off pulsewidth modulated over human ear max frequency (not remember freq, my mesured data is in worklab)... exept if you are whale. ;)
Also theres something odd with all the knobs (except volts/div and sec/div knobs). If I hold either of them up or press them down while turning they work oposite of what they should do. For instance, if I turn the trig knob right, the trig voltage should increase, but if hold it down (vertically) the trig voltage increases. This is really annoying because it's not much pressure thats needed before it changes direction. Anynoe else experienced that?
This I have not find but also have not test with more radial or axial force as turned. But normally handling I have not seen this. Sometimes, just as Rigol or Hantek etc who use this same kind of pulse encoders.. if slowly turn it can make step or two back or forward just as touch and start turning. After 10 minute use hand (fingers) learn it and adapt. I think it is quite typical for these cheap pulse encoders.
But if problem is more serious (as I think you mean) I have not find any key/knobs problems and I have seen many.
I hope they have not changed these components to some more cheap models.
If you really have problem with knobs, then it need make reclamation to Owon. (If it looks/feels really like production fail then they need warranty exchange.. (just after arrive if find fail it is "new fail" / "arrived as failed". And in this kind of real fail they need take all care and give free return - exchange after they service have classified it arrival failed. Maybe need also littlebit test and find good practice and teachj fingers how to handle... look one week and if you then really feel it is factory fail then start warranty exchange/repair process. (Owon do very good customer care (afaik) if there is real failed unit)
But these knobs are not as old tektronix knobs with 6mm metal shaft or HP with ball bearings... ;)
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Also theres something odd with all the knobs (except volts/div and sec/div knobs). If I hold either of them up or press them down while turning they work oposite of what they should do. For instance, if I turn the trig knob right, the trig voltage should increase, but if hold it down (vertically) the trig voltage increases. This is really annoying because it's not much pressure thats needed before it changes direction. Anynoe else experienced that?
Please tell also what is your version.
Vx.x.x
And serial number as
SDS7102yynnz--
(do not publishe these two last digits --)
I have tested this with one SDS7102 and one SDS8202
I have turned knops with extra radial force to all direction (left,up,right,down) with variable shaking and constant force. Also I have pushed knob same time as turned.
All times trace or trig line or cursors mofe just smoothly and right direction.
(of course radial force can not be high becouse mechanically it may damage but my "professional hand" I do it with "normal highest force" what is normal in any kind of use and normal hand user. )
(I have not here good force meter so I can not tell exactly but maybe around 0.3-0.6kp radial force And it feels really high for this kind of knob in normal whoever use. Also I try so high force to trig knob that it lift this end of scope and same force to up and down. now effect to trigger adjust line mowong as I turn sama time.)
So, if you have bad trouble with this, maybe knobs have damaged on the shipping. Can you imagine any signs in package carton that it may have handled badly in shipping.
If this problem is real after some more tests and looks like fail then you need immediately contact seller this person who sell it to you. This need handle as "arrived as failed". All buttons and knobs need work perfect and reliable as they are designed to work. But first be sure you have diagnosed it right for avoid extra confusion and hassle.
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I will tell you my version and SN as soon as I get back home from work. I will also check for damaged packages aswell.
You can compare the weight of the radial force I apply to the knobs with a mouse, literally. Just normal use like anyone would do.
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My serial number is SDS710211431--
Running version 2.3
No sign of damage on the box.
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Just unpacked my SDS8202.
SDS820211430**
V1.2.1
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Running version 2.3
Only two numbers V2.3
?
This knobs problem. Do they all have same problem (all 5 small turning knobs)
You need contact to seller and tell that there is this knob problem. Becouse problem is in new just arrived unit... "arrives faulty" They need repair or warranty exhange (immediately) it totally free for you. (they have fast system for exchange, but first you need contact directly your sales person and explain your situation so that it come fully clear that it is fail unit as 1-0)
Have you test all other knobs and buttons?
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Just unpacked my SDS8202.
SDS820211430**
V1.2.1
Thank your info. It seems that you have very new. Also FW version is new. Last one was V1.1.1 just short time ago.
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Running version 2.3
Only two numbers V2.3?
Yes, that's what "Utility -> About" said atleast.
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Owon stated that the revision string displayed in the "About" dialog is not changed by a firmware update, so it's kinda worthless to compare that string since you never now what firmware your Owon scope really has.
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Owon stated that the revision string displayed in the "About" dialog is not changed by a firmware update, so it's kinda worthless to compare that string since you never now what firmware your Owon scope really has.
Repair patches and updates are different.
Example: FW 2.1.1 original have error in FFT cursors, slow speed normal mode USB wave saving.
Update patch for these errors did not change displayed main version.
(also I remember before this was some other brand, that they also have hidden part in version numbers)
Example SDS7102 V2.1.1 and V2.2.1 have littebit different features.
V2.2.1 have also this repair but then it have also changes.
(bugs/errors repair is different case as develop useability and add features. After repair it continues just as version was designed but repaired some bug)
One example later have come tiny feature for naming USB files.
But 7102, 8102, 8202 they are different models and there is not direct relation between different models FW versions.
Example 8202 V1.1.1 have USB file naming feature ("keyboard" on the display)
There is of course one solution, Owon may hide totally this version number. After then there is no headaches.
but I remember someone talk that Owon have talked it is "mature" product and no FW updates... hehe.
Now I only want littlebit follow how it go forward..
but today I donnot know at all if displayed version is alone FW version number at all. There is possible also other meaning for his Vx.x.x
Later I try show to Owon how much they can save money if they change FW update policy.
(now they do lot of work to give update service to there and to here. Play with serial numbers and play with some block of serials etc and then (I have seen... they even edit update manual personally for nearly every single update.. how they can do so much work to make individual personalised update or repair patch update packages to around world)
If ask from basic sales person or basic customer care "automatic" answer "machines" it do not give any advantage. Only way is go to Owon kithcen.... and talk about food and weather... after eight (8 is important) lunch it is maybe possible to talk something interesting bisquits about what is possible other policy and method and if it give more money (or reduce costs) then they do it. Money is teacher, and only teacher who have the authority.
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A little offtopic, but is there any info if the "new" MSO (MSO7102TD, MSO8102T, MSO8202T) and PDS (PDS8102T/PDS8202T) scopes, which have a 2M point record length, have a full speed memory like in the SDS series?
According to the manual they have "2M points on each channel for the record length" - there is no word of "max" or limitations regarding the sampling rate. In contrary, the record length for the logic anayzer part is specified as "4M max storage for each channel" and later on there is a detailed specification which record length is possible for which frequency.
This sounds as if the 2M record length in scope mode was full speed (which is good) and can't be lowered for faster updates (which is not so good).
I got my employer to buy a PDS8202T for a great price and have used it only a few hours.
The specs only say that the record size is 2.5M points on each channel, not if it is reduced
at high speed. Since I have limited time on this scope and it doesn't have the friendliest
user interface, I can not even confirm if has this 2.5M point memory working. When I hit
"stop" and move the horizontal position, it does not seem to show 2.5M points, only what
is on the screen. Maybe I haven't figured out how to use the full memory yet.
One drawback of the PDS8202T versus the similar SDS models is that although it too has
a large 8 inch TFT screen, it is only 640x480, not 800x600. I didn't notice that when I looked
at the specs sheet originally. For those of you who remember using VGA screens, they look
a bit "cartoonish" compared to 800x600 or higher resolutions. Oh well, the price was right.
On another subject, as mentioned elsewhere, the Owon seems to be picky about the kind of
USB drives it saves waveforms too. Firstly, the documentation is not clear on this but you
select the waveform format not when you press the "U-disk Copy" key, but instead when you
press the "Display" key under "Carry" (??? how inscrutable is that?). I haven't figured out
how to save 2.5M points yet, it only seems to save what's shown on the screen.
The other issue is that the Owon won't save to some USB drives. I tried three different
ones and it only saved to one of them, a 1GB FAT32. On the other two, a 256MB FAT and
a 4GB FAT32, nothing happened, not even an error message. It may be that the Owon
only works with FAT32 and certain cluster sizes (see discussion elsewhere). I don't have the
time or expertise right now to determine the cluster sizes of my flash drives - I'm off on a
plane tomorrow with the scope to do some debugging.
I don't have enough time on the machine to make more comments. It seems to be worth
the low price we paid (about $US700), and as long as you're not expecting a $2000 Agilent, is a good deal.
Fan T.
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A little offtopic, but is there any info if the "new" MSO (MSO7102TD, MSO8102T, MSO8202T) and PDS (PDS8102T/PDS8202T) scopes, which have a 2M point record length, have a full speed memory like in the SDS series?
According to the manual they have "2M points on each channel for the record length" - there is no word of "max" or limitations regarding the sampling rate. In contrary, the record length for the logic anayzer part is specified as "4M max storage for each channel" and later on there is a detailed specification which record length is possible for which frequency.
This sounds as if the 2M record length in scope mode was full speed (which is good) and can't be lowered for faster updates (which is not so good).
I got my employer to buy a PDS8202T for a great price and have used it only a few hours.
The specs only say that the record size is 2.5M points on each channel, not if it is reduced
at high speed. Since I have limited time on this scope and it doesn't have the friendliest
user interface, I can not even confirm if has this 2.5M point memory working. When I hit
"stop" and move the horizontal position, it does not seem to show 2.5M points, only what
is on the screen. Maybe I haven't figured out how to use the full memory yet.
One drawback of the PDS8202T versus the similar SDS models is that although it too has
a large 8 inch TFT screen, it is only 640x480, not 800x600. I didn't notice that when I looked
at the specs sheet originally. For those of you who remember using VGA screens, they look
a bit "cartoonish" compared to 800x600 or higher resolutions. Oh well, the price was right.
On another subject, as mentioned elsewhere, the Owon seems to be picky about the kind of
USB drives it saves waveforms too. Firstly, the documentation is not clear on this but you
select the waveform format not when you press the "U-disk Copy" key, but instead when you
press the "Display" key under "Carry" (??? how inscrutable is that?). I haven't figured out
how to save 2.5M points yet, it only seems to save what's shown on the screen.
The other issue is that the Owon won't save to some USB drives. I tried three different
ones and it only saved to one of them, a 1GB FAT32. On the other two, a 256MB FAT and
a 4GB FAT32, nothing happened, not even an error message. It may be that the Owon
only works with FAT32 and certain cluster sizes (see discussion elsewhere). I don't have the
time or expertise right now to determine the cluster sizes of my flash drives - I'm off on a
plane tomorrow with the scope to do some debugging.
I don't have enough time on the machine to make more comments. It seems to be worth
the low price we paid (about $US700), and as long as you're not expecting a $2000 Agilent, is a good deal.
Fan T.
First, I have no any experience how to use these new PDS models yet (never mix new PDS and old PDS they are different machines "totally").
(and not old PDS models what I do not want never touch).
So with this disclaimer I continue:
Carry (in Chinese menu (I have looked chinese version paper) it can understand that it meand transported data type)
It means what format it carry data. But name is not problem becouse after one time learn it you know it. It can name what ever symbol what human can then remember.. (old some machine may use name TDFS or what ever.. hehe)
And selections are: bitmap or vector.
Bitmap is picture and vector is whole captured data just as ADC samples.
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Memory, manual tell that 2M points on each channel
Owon catalog tell: Max 2M points on each channel
(this is always confusing, btw, how fuck you can find what memory depth Agilent some infinii Vision use in different horz speeds if look manual or datasheet... I have not yeat find it, but they tell that scope is clever and it can select it automatically for optimize result... yess heheh)
Always it is good to read some datasheets and add term "up to"
With oscilloscopes it is samplerate and memory. Both are "up to" numbers and not always so that both together can be same time its "up to" value. Mostly not. This kind of things I hope ALL oscilloscope and equipments maufacturers specify better and more "truth" on the datasheets/specifications and in advertisements of course. (this is for all manufacturers starting from Rohde&Schwarz and ending to Siglent or Uni-toy.)
top of screen you see same kind of information row where is information how is screen window wide and position compared to whole captured memory.
If you stop capturing and zoom in with horizontal time/div knob you may find there are more datapoints. This is very common method with digital scopes.
How many sample points there are per one div (without zooming in or out) depends user settings, memory, samplerate etc.
This how they relate each others is good to learn. (basic learn how stuffs work and then learn how this individual scope model work what is on the table)
(look this table example what I have published for SDS series.)
Up to horz speed where reached maximum samplerate whole 1k to 10M (user selected) is inside 20 time divs. (there TFT itself is 15.2 div wide) So nearly just whole 10Mpoints are packaged to these 20 divs. After go higher horz speeds scope have reached maximum samplerate (for selected memory amount) and then only can add these divs. So screen is then more and more narrow window to whope captured data and this you can see in this information line top of screen line. (same kind of information you find also example Rigol or Hnatek and many others)
Now what ever you picture is but if you store vector data you can easy look that it have 2M vectors. (ADC sampled voltage level bytes. 8 bit signed bytes)
I do not know this new PDS serie if it is same kind of .bin file what is SDS serie.
If SDS want it to .csv mode it need convert with Owon convert tool.
-------------
(but this last with big smile ;) :) :) )
Now you're reviewing oscilloscope, although we should talk about that can you use it, and you understand how an oscilloscope works in principle. And this is very common problen around this forum -- including also myself -- up to highest level this forum.
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I can confirm, there is a high pitch noise coming from my SDS8202 when setting the display below 100% brightness. The display isn't overly bright at 100%, so I doubt you would ever set it below that. I actaully wish it was a tad brighter.
The Owon software/manual CD that came with my unit crashes MS Windows 7 as soon as it tries to autorun. It does however load fine on Windows XP.
Just got my SDS7102 and it seems really great. But I've noticed a couple of things.
When you turn down the backlight (Utility -> Function -> Display -> Backlight), do you hear a buzzing sound below 100%?
Can not hear any buzzing sound.
(main frequency for switching constant current driver is 1MHz. For dimming display its 1MHz output is on/off pulsewidth modulated over human ear max frequency (not remember freq, my mesured data is in worklab)... exept if you are whale. ;)
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I just tested SDS8202V in very silent room. Really I can not hear anything but fan quite low noise.
Then I test also with fan stopped. No any noise.
Now then I need correct littlebit, I remember wrong.
100% brightness thre is only 1MHz frequency before diode and capacitor.
<100% there is pulse width modulation what enables and disables this 1MHz.
To G5126 equivalent enable pin go 300Hz (in this unit nearly exactly 303Hz) variable pulsewidth signal.
There is one inductor L2 and this is type what do not easy make any noise.
(closed ferrite can).
So, it can not easy believe it product any acoustic noise what can hear. (exept if they have changed construction)
(but EMI noise it (whole scope) radiated some amount but not as much as these stupid "green" eco lamps... just as Pb free stupidities just also this... first make rules and after then thinking.)
But, peoples have microphone and I hope some give noise sample so that it can clearly regognize that it come exactly from oscilloscope and not from other source.
I use normally 50% setting.
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Definitely not the fan causing the noise on my unit. As you lower the display output the pitch/freq also lowers.
Maybe something is different with units that do not have the VGA output?
I just tested SDS8202V in very silent room. Really I can not hear anything but fan quite low noise.
Then I test also with fan stopped. No any noise.
Now then I need correct littlebit, I remember wrong.
100% brightness thre is only 1MHz frequency before diode and capacitor.
<100% there is pulse width modulation what enables and disables this 1MHz.
To G5126 equivalent enable pin go 300Hz (in this unit nearly exactly 303Hz) variable pulsewidth signal.
There is one inductor L2 and this is type what do not easy make any noise.
(closed ferrite can).
So, it can not easy believe it product any acoustic noise what can hear. (exept if they have changed construction)
(but EMI noise it (whole scope) radiated some amount but not as much as these stupid "green" eco lamps... just as Pb free stupidities just also this... first make rules and after then thinking.)
But, peoples have microphone and I hope some give noise sample so that it can clearly regognize that it come exactly from oscilloscope and not from other source.
I use normally 50% setting.
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I got my employer to buy a PDS8202T for a great price and have used it only a few hours.
The specs only say that the record size is 2.5M points on each channel, not if it is reduced
at high speed.
At the time, I also asked Owon support to confirm the record length/memory speed and after a while I got a rather vague reply. Anyway, I took from this reply that the PDS/MSO scopes have no option to set the record length and instead vary the record length automatically with the sample frequency. This hints that they don't have full speed memory and are inferior to the SDS line regarding this point.
Regarding the USB sticks: I got the confirmation from Owon that only USB sticks with a 4k cluster size are supported by the SDS line. I would suspect that this is also true for the PDS/MSO line. On my SDS this means that e.g. with a 8k cluster size, I can't store any files >= 8k. So for sticks >= 8GB which usually use an 8k cluster size or even more, you need to reformat them with a 4k cluster size to actually use them.
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Hello! I write with the help of google-translator from Russia.
Been thinking where to ask your question and decided to write here. I recently purchased a similar oscilloscope-SDS8102, but he immediately started having problems. I of course return it under warranty, but still I wonder what happened to him, software or hardware failure.
From the beginning, I was 100% sure that the problem is hardware, but now have doubts that maybe the software:
When you turn on the oscilloscope channel on both raised up in the zone and the frequency display on the first channel displayed a few hundred kilohertz, and the second a few megahertz, then after about 5 - 7 minutes the problem disappears. At the time these "attacks" the oscilloscope does not measure any signal.
Question. Who was such a problem as it solved, and which cause problems?
I hope google translated correctly :) .
Zdravstvuyte!
Dolgo dumal gde zadat' svoy vopros i reshil napisat' syuda. Nedavno ya priobrel podobnyy oscillograf -SDS8102, no u nego srazu poyavilis' problemy. Ya konechno je vernu ego po garantii, no vse je mne interesno chto s nim, programmnaya ili apparatnaya polomka.
S nachala ya byl 100% uveren chto problema apparatnaya, no seychas est' somneniya chto mojet i programmnaya:
Pri vklyuchenii oscillografa oba kanala na ekrane podnyaty vverh i v zone indikacii chastoty na pervom kanale otobrajaetsya neskol'ko soten kilogerc, a na vtorom neskol'ko megagerc, zatem primerno cherez minut 5 - 7 problema ischezaet. V moment etih "pristupov" oscillograf ne izmeryaet ni odin signal.
Vopros. Byla u kogo takaya problema, kak ee reshili, i kakaya prichina neispravnosti?
Here's a video example (video primery):
OWON SDS8102_#2 (https://www.youtube.com/watch?v=5McI7cKoEUA&hd=1#ws)
OWON SDS8102 (https://www.youtube.com/watch?v=Zvj0YQBs0hg&hd=1#ws)
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pofigist, your videos appears like an internal fault within the scope. Like a quality control assembly problem.
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To profigist:
With my experience with Owon SDS series oscilloscopes, including service, my tight and quite sure opinion is:
Your oscilloscope is faulty.
Please take contact to seller and ask warranty repair or warranty exchange.
I classify it as failed becouse traces randomly disappear and come back frequently. This video is enough for classify it as failed.
Also these sharp "edges" if look your video single frames just as traces disappears or come back and together with these freq counts numbers.
Strong suspicion of almost certain hardware fault.
Of course you can also do selfcalibration for more examination and if it fails it is more document for fail. (but this looks very clearly faulty so not specially need do any more examinations)
First, do "default".
Traces need be nearly vertically same amount from center line. (-1div and +1div)
Push both channels vertical shift know, both traces go to center line.
Turn both channels Volt/div whole scale starting from 10mV/div.
Traces need stay just near center line. (same with AC setting and DC setting)
If not, do selfcalibration and check agen.
But, becouse this random trace shift out from TFT/totally disappear without touching scope and inputs just without any signal it happends randomly ==> Fail.
Warranty repair (main board and/or adapter board change) or better warranty exchange just becouse it is new arrived "DOA" (arrived faulty)
//
If you purchased it from seller who do not care plese contact directly to Owon China. Also in this case please tell to Owon who is this seller. (only if seller do not take care about your situation)
Give information about serial number and explain that it is just arrived new oscilloscope and short description about fail. And these videos.
They can not maybe look youtube so you need upload these to some place what can realiable use in China.
With Owon if you have problem you are not alone. Specially if you have purchased it from good an authorized dealer (example me but only locally in Finland).
If you need contact to Owon please ask they give free shipping becouse new arrived oscilloscope is faulty.
[bFirst ask your seller![/b]
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I have the 8102 as well and mine doesn't show this behavior. I figure you're using the 100ms/div timebase, 1V/div for the voltage and you connected the ground of both probes to the ground of the test output.
With this configuration, there is a little noise visible on both channels, but not the disturbing behavior that you observe.
BTW: at 100ms/div, the sample rate is displayed as 5MS/s on my 8102, while yours displays 5KS/s. I tend to believe that the 5KS/s is more realistic in 100ms/div rolling mode. Anyway your firmware revision seems to differ from mine. So it could be also a firmware bug. Anyway to me it looks more like a hardware issue.
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I tend to believe that the 5KS/s is more realistic in 100ms/div rolling mode. Anyway your firmware revision seems to differ from mine. So it could be also a firmware bug. Anyway to me it looks more like a hardware issue.
This looks quite good table. (https://www.eevblog.com/forum/index.php?topic=4412.msg69802#msg69802)
In Scanning mode, displayed information about samplerate and used true memory size is not ok. It is FW bug. If you turn it normal or single shot slow speed mode information on the TFT is correct. This situation may change what ever time by Owon.
//
Not personally to any named person. For all:
This is also important to understand. As you (some) purchase product you (some) also accept this becouse this is part of product and deal: Owon legal statement:
Quote
"OWON will continue to improve products and reserves the rights to changes specification at any time without notice."
Quote end.
Product is as customer have purchased it and there is no any promise that Owon will continue improving this individual unit what you (some) have purchased.
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Thank you all for your answers.
Oscilloscope I rechecked all modes, which I could find in it, resets to the factory - and nothing changed. Mode 5Ks / s, 100ms I turned to a more graphic display of the anomalies on the screen.
I bought my oscilloscope in the Russian internet shop "Platan". In this shop, I always bought electronic components in small batches and not what it claims to not be.
Today, wrote a letter to e-mail store, but so far no reply has come (day off). hope for tomorrow.
---------------------------------
Vsem spasibo za otvety.
Oscillograf ya pereproveryal vo vseh rejimah, kotorye ya mog v nem nayti, sbrasyval nastroyki na zavodskie - i nichego ne izmenyalo. Rejim 5Ks/s, 100ms ya vklyuchal dlya bolee naglyadnogo otobrajenie anomaliy na ekrane.
Priobretal ya svoy oscillograf v rossiyskom internet magazine "Platan". v etom magazine ya vsegda priobretal elektronnye komponenty melkimi partiyami i ni kakih k nim pretenziy ne bylo.
Segodnya napisal pis'mo na elektronnuyu pochtu magazina, no poka otveta ne prishlo (vyhodnoy). nadeyus' na zavtrashniy den'.
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Tried to capture the highpitch noise from the backlight with my mobilephone;
OWON Sds7102 Oscilloscope backlight noise (https://www.youtube.com/watch?v=gAwyYWAmrfM#)
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I have actually had an email chat with Owon - and I told them to listen to you guys here :-)
I'm very close to putting in an order for the SDS8202 with LAN and maybe battery option - if we can get the "travel allowance document" for the battery sorted. :-)
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I have actually had an email chat with Owon - and I told them to listen to you guys here :-)
I'm very close to putting in an order for the SDS8202 with LAN and maybe battery option - if we can get the "travel allowance document" for the battery sorted. :-)
http://www.iata.org/whatwedo/cargo/dangerous_goods/Documents/LithiumBattery_PassengerFlyer.jpg (http://www.iata.org/whatwedo/cargo/dangerous_goods/Documents/LithiumBattery_PassengerFlyer.jpg)
Where it need "travel allowance document"
Separate (spare) battery can take to inside "carry-on package" they can not insert "checked package".
Battery assembled inside oscilloscope, this oscilloscope can insert "checked package" and/or "carry-on package".
It is classified as chargeable Lithium polymer battery (LiCoO2) and power rating is <100Wh (they are looked as capacity Wh and Owon SDS batteries are 60Wh (7,4V 8000mAh with control circuits.)
I have travel around and never get problems with any litium batteries if batteries are inserted to equipment. (eg camera, video camera, laptop, oscilloscope. No one have never ask any kind of documents. But not any experience specially with Owon.
When Owon batteries travel in fly cargo (example TNT/DHL/FeDex etc) there is always battery safety informations sheets included from battery manufacturer who is:
Hangzhou Wanma High-Energy Battery Co.,Ltd.
Sales Centre: 118# Linban Road,HangZhou,China P.C.? 310022 E-mail: sales@wanmabattery.com
Tel? 86-571-88368608?English language available) 86-571-88368618 Fax? 86-571-88368922
But if you send separate cells, it may be sometimes difficult dependent of cell type and amount.
Limits and requirements can read IATA rules book.
Well of course there may be some countries what want follow more rules than IATA.
But als I'm interested how Owon answer and also if there is some new rules or other info related to travel and Owon battery.
Also this Aktakom ADS-2111M (rebranded Owon) use exactly same battery. So also www.tmatlantic.com (http://www.tmatlantic.com) may have this battery information allready.
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Items containing batteries coming out of China needs a UN38.3 test report says my shipping agent. That does not matter if it is a mobile phone or any other device with a battery.
Some manufactures might "forget" that the item contains a battery and ship it anyway.
But a SDS 8201 with LAN, SVGA and Battery - cant wait - even though I really want an Agilent MSOX 3014/3024... But the st***d dealer here have horrible prices so I will NOT buy from them. So an interim SDS8202 will have to do until I find a good offer for the Agilent.
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I know that DHL Express (air cargo) have never meet problem with these batteries in my experience.
All times Owon send batteries they include Hangzhou Wanma company copy of: Material Safety Data Sheet.
I can quarantee that if your shipper know what they are doing, there is not any problem for ship these batteries out from China by Air cargo... and also... most shippers go first To Hong Kong and from HK around the word. There is so also 2 security and Customs check.
I have order these "more than once" and really more than single battery from Owon.
And oscilloscopes do not contain battery but afaik they are separately packaged inside same carton (I have not asked if they can send so that battery is allready assembled but then they still need include this empty battery block what you can install if not use battery.
(better that they send separated from oscilloscope but in same carton, so customs officers and/or security officers can check these as they want becouse Battery reads in packing list and invoice. If they are inside oscilloscope then maybe some stupid security people want take them out for check and if they do not want do this (need work and may scratch you scope then maybe problem)
There are lot of Owon oscilloscopes and batteries around of world and all they have travelled out from China with some DHL or equivalent and mostly air cargo.
You do not trust Owon that they can ship these? ;) :)
Believe me, they know what they are doing. They are not as "grey" ebayboys
There is no any problem. Automatically they include this safety datasheet. They are not stupid. Also They know what China safety checks need.
Hangzhou Wanma Material Safety data Sheet is totally 3 sides. It is included to shipping papers. And always they have traveled without any problems. And there is also this chapter:
Transport information:
Polymer Lithium Ion rechargeable batteries are regulated during shipment by Dept. of Transportation (USDOT) and United Nation's (International) requirements. Batteries tested and found in compliance with UN Chapter 38.3 requirements may be shipped without designations as "Class 9" hazardous material if all other marking, labeling, packaking, and unit volumes are met. For specific details, please visit: http://www.wanmabattery.com (http://www.wanmabattery.com)
the International Air Transport Association (IATA) 45th Edition, dangerous Goods Transportation, or 49 CFR Transportation regulations for further details to your shipping situation.
So, you can see these kind of things they really know and have thinked.
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I do know Owon can ship via DHL. My other shipper is just about 1/2 price compared to DHL Express. So I'm going the DHL route.
My other shipper (Aramex) has a "ShopAndShip" system so I have a real local address in the UK, US and in China... :-) Everything sent there get's forwarded to my UAE address. :-) And Aramex are cheaper on "single items".
From the US i use MyUS.com - but they are getting real bad. They used to be perfect but now they have turned in to a heavy elephant with lousy response times and now little thing costs money.
anyway - did not want to sidetrack the discussion. :-)
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I'm very close to putting in an order for the SDS8202 with LAN and maybe battery option
I hope you are aware of the limitations of the 2GS/s range that we discussed in this thread some time ago...
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I'm very close to putting in an order for the SDS8202 with LAN and maybe battery option
I hope you are aware of the limitations of the 2GS/s range that we discussed in this thread some time ago...
Yes I know. But I am in the UAE :-) and to get best resale value here it needs to be big.... :-) anyway not often I need more than 100MHz or 10k pts anyway. Just a good test scope to start with. It is not $100 that changes the picture.
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If You are interrested in You can find some more tests about my new SDS8102 and detailed pictures from the inner parts here:
http://www.mikrocontroller.net/topic/238863#2425297 (http://www.mikrocontroller.net/topic/238863#2425297)
My version is 2.0 and my official dealer (for germany) promised me to get some fresh firmware from OWON. So I'm waiting for that because I detected a bug which wasn't reported before (or I didn't find it).
My pulse width trigger isn't working in any way. Con anyone here confirm the problem? I tried pulses from 6ms width to 40ns width but it doesn't work.
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There are also some other kind of trigger bug(s) and maybe even more severe. (I have heard... 8) )They are now working in Owon for fix 8102 and 8202 and later get ready FW update.
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My version is 2.0 and my official dealer (for germany) promised me to get some fresh firmware from OWON. So I'm waiting for that because I detected a bug which wasn't reported before (or I didn't find it).
thanks for the info - i just received my 8202V with LAN straight from Owon and it says V1.3? (Utility/Function/Config/About) - is that where yours says v2?
Keep us posted on firmware updates. :-)
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Very nice review Blueflash, I wish it was available in english, google translate does not do it justice.
Regarding the pulse width trigger issue, I think it is a bug. I have a SDS7102 and IIRC it is the same, but if I choose negative polarity it triggers on positive pulse, and vice versa. I even reported this to Owon, but received only typical response "thank you, please give us your serial no bla bla".
BTW, Blueflash is famous :) developer of open source firmware for Welec 2000 series of oscilloscope. HW of the scope is below average, but his firmware kept it alive and kicking for the past 3-4 years!
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Correct - version can be seen on the attached picture (was't easy to make it 8) )
How did You get a device with LAN - lucky bastard... ;D
My official dealer didn't offer any LAN option for any device.
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p.s. reached my DSO on last Friday. The dealer said it was delivered the week before ( around 9. of Nov)
If Firmware is available I will post it here.
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p.s. reached my DSO on last Friday. The dealer said it was delivered the week before ( around 9. of Nov)
If Firmware is available I will post it here.
I got mine straight of the factory since there are no dealers where I am. But i'll ask why i have a version 1.3 firmware. Maybe mine is an old HW version (Got it with Battery, LAN SVGA etc and carry bag) - quite impressive kit to be honest. Much better quality than I expected. Right now i had it only for a few hours... :-) And so far Owon has been very responsive and professional.
/Kasper
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7102, 8102 and 8202 FW numbers are not comparable.
Example (I know only this situation with these individual units)
8202V V1.1.1 is new and seems be functional exactly same as 8102V V2.1.1V
Inside one week Owon headoffice tell this 8202 FW is new and not need update. (and people who tell it was not people who are normally answering thousends of emails)
(both these FW have virtual keyboard for naming stored files (this virtual keyboard I hope they do more clever or later add touch function to display.)
Imho, it is also possible that example LAN option model have different FW and same about RS232 model without VGA. This I do not know, only littlebit suspect.
Why Owon ask serial number. Of course they ask. There may be small differencies in HW versions and so on.
Also mostly to customer shared FW updates are locked to serial number. This is why they ask it.
And it is well protected. This is not as Hantek who keep doors and windows fully open.
(also you can see other name these same oscilloscope. Aktakom is one and there are also others. So Owon need also protect they product also just becouse they walk they own roads and do not copycat products as most of chinese)
Also I know Owon is working with new FW agen for fix some problems but also they do not want give changelog or even FW version log and not "known bug" list.
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Yes, seems You are right. But even my dealer who is "only official dealer in germany" did not know that there are differences in firmware versions. Hope he will get the right version for my device.
Btw - my device is a VGA-Out version too and I didn't find a RS232 preparation on the board. Only for the LAN connection. So there must be different mainboard layouts for the versions with RS232 and VGA. Strange concept...
Also the firmware concept, for they have to compile every firmware separately for every owner?
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@Nermash
I'm sorry that the postings are available only in german. If wished I could make an english version about the changes/optimizations I made in the DSO.
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I have 8202V with LAN Firmware 1.3 - and I have virtual onscreen keyboard. But I found a bug trying to save IMAGE to memory stick - the scope just froze. I can replicate it - happens on first or 2nd image capture. (SAVE/IMAGE/(virtual keyboard)/ENTER) - one or 2 images and that's it.
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@Nermash
I'm sorry that the postings are available only in german. If wished I could make an english version about the changes/optimizations I made in the DSO.
i for one would love that.. I do read german but NOT that technical german :-) ..
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Ok, I will work on it. maybe it is available tomorrow as pdf
My version does save the screenshots - but not on every USB-stick! The 16GByte Stick freezes the device,
the 2GByte Stick lets appear a popup which informs me that only fat32 is accepted but my 8GByte stick works.
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Ok, I will work on it. maybe it is available tomorrow as pdf
My version does save the screenshots - but not on every USB-stick! The 16GByte Stick freezes the device,
the 2GByte Stick lets appear a popup which informs me that only fat32 is accepted but my 8GByte stick works.
If you read a little through this thread you'll find that only 4k cluster sizes are supported. As Windows usually uses larger cluster sizes for 16GB and some 8GB sticks come with larger cluster sizes as well, you need to reformat them with 4k clusters. Owon is aware of it, but they don't intend to change it (and want to document it instead).
BTW: is it known if the versions with/without VGA connector share the same firmware?
BTW2: Präzitronic also promised me to supply me with a new firmware and nothing happened in one month. Then again, I got one from Owon directly, but it didn't really fix anything.
BTW3: also mentioned before here, but updating the firmware doesn't change the firmware revision string. This was also confirmed by Owon. So indeed the string displayed in the About dialog seems to be more or less random and has nothing to do with the real revision.
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Oh thanks for the information. I tried to read most of this thread but indeed it is very long now and due to this I overread some items I guess. But it is good to know that reformatting can solve the problem.
So You bought Your DSO at the same dealer as me - interesting! I will try to get on their nerves with phoning every second day - maybe this will motivate them to do something. Otherwise I will exterminate them in the german blog... >:(
If the version string doesn't show the version, what does it show??? What is it for?? That's no good way in the world of internet communication to make Your product a good thing to buy.
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So You bought Your DSO at the same dealer as me - interesting! I will try to get on their nerves with phoning every second day - maybe this will motivate them to do something. Otherwise I will exterminate them in the german blog... >:(
I don't wanna be unfair. They replied after one week and said there were still trying, but then they seem to have forgotten about me. Also I got a 100€ refund as I complained that the record length limitation at 2GS/s was not documented and I wanted to swap into a 7102. So I kept the 8102 for more or less the price of a 7102. Still the 8102 seems to be a little buggier than the 7102, but yeah well. So I can't really complain. Mainly it's Owon's fault with their crazy update policy.
If the version string doesn't show the version, what does it show??? What is it for?? That's no good way in the world of internet communication to make Your product a good thing to buy.
Well, tinman/tinhead confirmed that the application updates don't contain the text files at all, where e.g. the version string is located.
Why the Owon guys decided that this would make sense is another question. Why do they use "v" instead of "V" for Volts? What is the "dots" mode for if it doesn't display the sample points? Why didn't they implement triggering on both edges? Why doesn't the "Copy" button use the settings defined in the "save" menu? Why isn't it possible to store both channel datas at once? Why do they encode the firmware, but decode it before sending it to the scope with a public key that's also called like this? Why do they hide the firmware updated from their customers?
Maxbe they are not the brightest, maybe they just don't care. Probably a mixture of both.
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As promised yesterday here the manual for the changes I made and the original service manual. For this blog does not allow files bigger than 1MB I posted them in the german thread. You are welcome to download it from there.
http://www.mikrocontroller.net/attachment/126522/SDS_Series_Oscilloscopes_Service_Manual_v1_0.pdf (http://www.mikrocontroller.net/attachment/126522/SDS_Series_Oscilloscopes_Service_Manual_v1_0.pdf)
http://www.mikrocontroller.net/attachment/126966/OWON_SDS_Series_-_Optimizing_Hardware_EN.pdf (http://www.mikrocontroller.net/attachment/126966/OWON_SDS_Series_-_Optimizing_Hardware_EN.pdf)
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Do you have any measured data about "before" and "after". What are measured improvements? (I mean raw measured data).
This method for fix metal plate where are input BNC. It is becouse service. This can take off with one nice wide heater. After soldering here and there it is not easy serviceable. (in factory routines).
Mechanic is designed so that if need take base plate out there no need take power board out.
Adapter board can move 5mm to under power board and it can take out from main board connector.
And whole baseplate can then lift off together leaving main board together with frontpanel board.
Now if have service cable between adapter board and main board it can power up for example front end capacitors adjusting or example change fan. (it need note: handle fan as very fragile! This fan model bearings damaged very easy with extra force (fingers etc) when handling baseplate.
On the adapter board is also backlight driver. Some versions have dim display becouse they have adjusted (with fixed resistor) this current too low. Nominan current for display LED backlight is 180mA. (current can measure without taking off LED connector. (but keep care do not force it under 5-6V when measure current. Use example 7x1N4148 series with current meter) (measure current between connector... time when measure current go to meter and LED's shut off.
Typical value for R17 is 1R0 - 1R4
(do not make mistake if read value marked on resistor... sometimes they have soldered two resistors...)
250MHz SDS7102 (and 500MHz) SDS8xxx need reduce. It can do only changing ADC area on the board. (Grounding is not best possible, analog and digital ground HF separation lacks. This is my suspect, I do not first think it problem is on the RuiFeng ADC silicon)
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There are no measured improvements! This changes are not made because of known problems in signal integrity. It was only the wish to make it a little bit more perfect.
(I love it to disassamble devices and to make some changes on it... :) )
You are right with the argument of making service a little bit more difficult. Also be aware that these changes may let You loose waranty!
So this changes are not a "must" but only a "nice to have" option and it is up to You if You want to make it.
Measurements from "before" You can see in the mikrocontroller thread. You will see that there is nothing to complain about the signal acquisition. What I didn't tried is to measure a small signal with VGA out switched on. Can anybody with a VGA out option check this? On my device there is no crosstalk fom VGA to ADC measurable.
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translator (English):
Hello. I'm on the fault of my oscilloscope described above.
Contacted OWON (China) , for me they are advised to update the software and sent to the firmware version 2.0.
Firmware problem is not resolved!
---
original text(Russian):
Zdravstvuyteyu Ya po povodu neispravnosti moego oscillografa opisannoy vysheyu
Svyazalsya s SchCSchT (Kitay) mne oni posovetovali obnovit' programmnoe obespechenie i prislali proshivku versiey 2.0.
Proshivku problemu ne reshila!
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translator (English):
Hello. I'm on the fault of my oscilloscope described above.
Contacted OWON (China) , for me they are advised to update the software and sent to the firmware version 2.0.
Firmware problem is not resolved!
What FW problem?
Before you have sent this message:
"Re: Review of Owon SDS7102
« Reply #373 on: November 13, 2011, 01:33:23 PM »
"
In this message you show problem.
It looks like HW problem as described before.
Where fromm you get opinion that it is FW problem.
I heve looked your videos and it is 99% sure HW manufacturing fail.
Contact to Owon china service if your local reseller do not understand anything. You have faulty product what need repair or warranty exchange. This forum do not repair it.
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translator (English):
Hello. I'm on the fault of my oscilloscope described above.
Contacted OWON (China) , for me they are advised to update the software and sent to the firmware version 2.0.
Firmware problem is not resolved!
What FW problem?
Before you have sent this message:
"Re: Review of Owon SDS7102
« Reply #373 on: November 13, 2011, 01:33:23 PM »
"
In this message you show problem.
It looks like HW problem as described before.
Where fromm you get opinion that it is FW problem.
I heve looked your videos and it is 99% sure HW manufacturing fail.
Contact to Owon china service if your local reseller do not understand anything. You have faulty product what need repair or warranty exchange. This forum do not repair it.
I think also that is a defect in the soldering chips in BGA package. over time defect will increase only. repair requires specialized equipment and sufficient experience. You should seek a specialist or send DSO to manufacturer.
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You should seek a specialist or send DSO to manufacturer.
In this case only acceptable specialist is Owon service. Local or manufacturer in China. Ask normal RMA process.
This forum do not anything for repair it. Owon or first your local seller is right address. Owon is reputable company who have also warranty time repair system and just normal RMA handling process. If your seller do not understand how to do and handle this kind of normal but rare cases then ask your seller that he come here. Then here we can give public teaching what to do and how to do. World is full of stupid sellers who do not care anything. They sell oscilloscopes or other equipments just as beer bottles.
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Muxa52, rf-loop,
Yes, I do not expect this forum to help repair. I myself am 99% sure it was a hardware problem, but after flashing to 100% convinced. I just wrote to the court the result of his actions and correspondence with OWON. And at the moment has finally answered the seller and I will send back an oscilloscope ...
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Muxa52, rf-loop,
Dya ya i ne jdu ot dannogo foruma pomoschi v remonte. Ya i sam na 99% byl uveren chto eto apparatnaya problema, a posle proshivki ubedilsya na 100%. Ya prosto napisal suda rezul'tat svoih deystviy i perepiski s OWON. A na dannyy moment nakonec-to otvetil mne prodavec i ya otpravlyayu oscillograf obratno...
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Muxa52, rf-loop,
And at the moment has finally answered the seller and I will send back an oscilloscope ...
This is good.
And this case it need handle as: "Dead On Arrival" = DOA
(in this case Faulty On Arrival (FOA) is better but this is not in common use )
This was faulty on arrival. Not faulty after period of use. If it fails after some period of use but inside warranty time then it is normal warranty case. Now this is clear DOA case.
If your seller work tightly with Owon he know that Owon have good service for DOA or normal warranty time cases. (they have normal good working RMA procedure)
Owon is not "chinese grey company" who do not care - they care. But naturally becouse they are manufacturer and manufacturer e-mail capacity can not meet well for every single end users. So it is of course better that end users communicate first priority with local sellers as is normal in all where is manufacturer and then lot of local sellers.
Quote from Wiki for this DOA term:
Popular usage
Colloquially, anything which is received in a non-operational (broken) state can be called DOA or dead on arrival (or, alternatively, defective on arrival). If a new product, such as a computer, arrives "DOA" then it is likely that the recipient will call the supplier to get a Return Merchandise Authorization (RMA), a transaction that acknowledges that (apparently defective) goods will be returned to the supplier for refund, replacement or credit. Sometimes it is difficult to actually detect a defective or DOA product. With computers, for instance, it might require a boot image to be installed and run through a test suite to detect any failed parts.
When, as with computers, product complexity is high and diagnostics are involved, the medical metaphor is perhaps appropriate, as complex diagnostics might be required to determine if the product "is really dead".
In another context, "dead on arrival" may be used to describe an idea or product that is fundamentally flawed, and therefore viewed as an utter failure from the start. For instance, if television producers decided that a pro wrestling tournament were to air on a women-oriented network, the concept would be considered "dead on arrival".
Many ebay seller also wrong use this term. (Or eBay DOA is different DOA as buying new things from factory)
They think (sometimes) that if I buy some equipment it can be faulty and it is not DOA becouse power on turns some light on. (becouse there is some sign of life it is not dead... hehe)
sidenote:
Be careful this DOA term if buy something from eBay and specially from some western countries as example US becouse every US people know that one light in spectrum analyzer means that it is not dead... so if he promise it not DOA and there is one lamp on after power on, it is just as he have promised. I know this - with experience!!!
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sidenote:
Be careful this DOA term if buy something from eBay and specially from some western countries as example US becouse every US people know that one light in spectrum analyzer means that it is not dead... so if he promise it not DOA and there is one lamp on after power on, it is just as he have promised. I know this - with experience!!!
Always assume the worst. If it's guaranteed to be non-DOA, then I expect the power light to light up at least once after power on. It may die at that point, or have major defects. If it were fully working, the description would have been 'guaranteed fully working'. With these assumptions you'll be rarely disappointed, and sometimes pleasantly surprised. Testing means that someone pressed a few buttons and got some sort of response. Calibrated probably means it was hooked up to an out-of-spec voltage source and the numbers looked plausible. Maybe someone adjusted some random trimmers so the 9.9V source read exactly 10.000V. If you expect the seller to do a full performance verification to see if it matches the factory specs, eBay is probably not the best place to look.
This, somewhat tongue-in-the-cheeck, description by HP_Agilent list member Phil Parsons is quite apt in my opinion:
POWERS UP
Indicator light came on, possibly momentarily. Then switched off before smell of
burning became too strong.
WORKS
Switched on without excessive smoke/fume or flames.
TESTED
AS above but some controls twiddled at random.
FULLY TESTED
AS above but may show signs of life.......
CALIBRATION STICKERS.
From when?????????? You have to be kidding. I wasn't born then!
CALIBRATED
Had a poke around inside -- what are all these little things you can twiddle?
This is fun -- my 2 year old child had a great time. May never work again.
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So, I got a respond from owon regarding the backlight issue and they sent me a firmware update which surprisingly fixed the problem!!
Something I noticed with this update is that the backlight brightness is stepped 20% a time instead of 10% which it previously did, not an issue for me tho as I don't even use the functionality. :P
"Utility -> About" says its version 2.4.1, up from 2.3.
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So, I got a respond from owon regarding the backlight issue and they sent me a firmware update which surprisingly fixed the problem!!
Something I noticed with this update is that the backlight brightness is stepped 20% a time instead of 10% which it previously did, not an issue for me tho as I don't even use the functionality. :P
"Utility -> About" says its version 2.4.1, up from 2.3.
Utility -> About" says its version 2.4.1, up from 2.3. <-- oh, now they have worked unexpected fast...maybe coffee is better than green tea... sometimes. ;)
It maybe change this frequency how it swithch "on" "off" this LED driver circuit.
(different FW may have different this "Enable" PWM base frequency... this only suspect)
Sidenote: Innolux specs for LED's voltage is around min 9,3 - max 10,5V with nominal current 180mA.
(looks like min is more like typical)
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Somlioy, do you have a contact there at OWON or maybe a link to their download page for firmware updates? I just posted about this on an SDS8202 a little while ago, but have not yet tried to contact them. Thanks for the info regardless, that's encouraging!
https://www.eevblog.com/forum/index.php?topic=5736.0 (https://www.eevblog.com/forum/index.php?topic=5736.0)
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Somlioy, do you have a contact there at OWON or maybe a link to their download page for firmware updates? I just posted about this on an SDS8202 a little while ago, but have not yet tried to contact them. Thanks for the info regardless, that's encouraging!
https://www.eevblog.com/forum/index.php?topic=5736.0 (https://www.eevblog.com/forum/index.php?topic=5736.0)
Owon have not public download center.
You can send email to Owon and tell problem and ask if FW update maybe solve it. They ask your full serial number and some day they may send to you FW (normally serial number locked)
(with serial number database they know what is ok for your HW)
After Sales Service: service at owon dot com dot cn
But if you have buy it from local distributor "please first contact local distributor".
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Yeah, I got the firmware directly from owon.
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Yeah, I got the firmware directly from owon.
if you don't mind uplad the firmware somewhere and send me a link (PM).
I might need it to continue the hack.
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Hi Folks,
got a new info from my dealer. OWON will make the firmwareupdates available on the official website for all SDS models.
Planned start of the download site is mid of december.
This would be nice and quite more comfortable.
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Hi Folks,
got a new info from my dealer. OWON will make the firmwareupdates available on the official website for all SDS models.
Planned start of the download site is mid of december.
This would be nice and quite more comfortable.
I was told the same by one of the Owon seniors a week ago - but was not given permission to publish it :-) But I got same message - so that is good getting confirmation from someone else :-)
I think Owon has started to listen - and does follow the discussion both here and Mikrocontroller.net
:-)
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It's cool to hear that it's actually true, but there were hints more than one month ago that this could happen. Earlier in this thread I posted a quote from a mail I got in late October which commented on one of the bugs I reported with "... can be solved by upgrade that we'll have a new software for this on our website."
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Owon have also developed SDS.
They have changed whole front end construction. (and also some other construction things what have been not so good). Whole adapter board is designed agen and also mainboard have lot of changes. So, all pictures and opinion about some construction details what you have here seen. Most of these are now obsolete!
Of course some part of development is for manufacturing process so that assembling is more ergonomic and some work phases need less work and also mistake posibility is reduced.... etc. (normal production development) But most of these also give better reliability and better functioning.
Also they have changed some relays to better quality.
Old talking about dim display. Forget also, now they drive baclight with full Innolux specified current. (this really do not matter in battery use. And if really critical time user can adjust it but maximum is not now limited too low)
and so on...
later, after I can do more labs, then more real data, not opinions.
But this I can tell as preliminary for frequency response and risetime etc... Owon have done very good work.
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rf-loop ... pictures please :)
(editing my comments right now ...)
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rf-loop ... pictures please :)
(editing my comments right now ...)
I have not any public pictures.
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I have tested one new individual SDS7102V
Using 1MHz as reference level.
V/div 50mV~
Signal exactly 6div p-p
Single and double channel in use.
Flatness is extremely good. Just flat up to around 85MHz
Before there was small high between 40 - 60MHz. (nearly +1dB, some variations between single units)
Now response is just flat.
100MHz -0.6dB This is good.
Single channel in use:
-3dB >200MHz (result was around 240MHz but this test need repeat and cross test with other equipmen for avoid error)
-6dB >300MHz (result was around 350MHz but this test need repeat and cross test with other equipmen for avoid error
Measured with good coaxial cable and Tektronix 50ohm feed thru terminator on scope input.
Generator is HP8644B and checked its flatness is perfect and inside specs.
Also I noticed that 250MHz noise is around 6dB more low than before. (but also before, individual units have differencies... I have find around +-5dBvariations between single units so this finding is not meaninful before test more units and can see if average is really better now.
This freq response finding was real surprice.
But also we know that if scope is named as 100MHz scope it is nice if flatness is very good up to this frequency, and now this is. If take some 200MHz (1GS/s) ready made oscilloscopes this 100MHz Owon is good competitor and it may even win.
Becouse this scope have also lot of capture memory with full speed up to 10M it keeps 1GS/s or 500GS/s up to 500us/div or up to so aliasing problem is not very high becouse Nyquist is 500 or 250MHz up to 500us/div if single channel use or with 2 channel use up to 1ms/div.
So, this scope do not need any posibility to hack BW. This is working tool, not hacking hobby object.
Good 100MHz oscilloscope and 200MHz oscilloscope if look many competitors ready made 200MHz scopes.
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>200 MHz -3 dB point is awfully close to the 250 MHz Nyquist frequency for a 500 MS/s sample rate. I'd expect aliasing to be an issue.
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>200 MHz -3 dB point is awfully close to the 250 MHz Nyquist frequency for a 500 MS/s sample rate. I'd expect aliasing to be an issue.
In single channel use as there read. (but analog BW is also of course with 2 channel.)
Yes aliasing is always problem with all low price digital scopes and also with expensive scopes.
If need really scope what never have aliasing problem it can buy analog oscilloscope. I want some day find littlebit better analog (today my analog limit is around 500MHz... but if find 1GHz analog (Tek 7000 series) maybe it is solution..
More aliasing with models what have not deep full speed memory and becouse this they, with lower horizontal speed, drop samplerate to very low.
Now this measurement was also done without probes. Probe is good filter. ;)
Single channel it use 1GS/s down to 500us/div. (With 2 channel it use 500MS/s down to 1ms/div)
1ms/div. Nice for looking 1kHz. I can not imagine how much 250MHz signal is together with typical case when looking 1kHz.
If looking fast rising pulse edge. Well yes it includes high frequencies. 1ns risetime and there it go.
In what kind of situation you mainly mean this aliasing problem (if keep mind where we are in price class and competitors)
Two channel use and signal have markable amount >250MHz frequencies if use 2ns/div - 1ms/div speed per div. If look audio signals and afraid high frequencies aliasing... well. There is 20MHz BW and around 5MHz if switch probe to 1:1. And it is good to note, 1ms/div and looking example 1kHz or 500Hz signal... and yes... if there is >250MHz doughter signals with this low freq signal they do aliases.
Where is other cheap oscilloscope what sample 500MS/s for both channels if using 1ms/div speed.
If there is other 100MHz scope what have corner freq around 100-130Mhz and samplerate is example 50MS/s in same 1ms/div situation.. well... nyquist is 25.. and analog channel is widely open up to >100MHz but becouse it is not Owon.. it is not problem even if it is famously hacked to 100 - 200MHz... now it hack is welcome... so where is real problem.
Just with these aliasing problems it is easy understand whu full speed deep capture memory is extremely good. Some peoples have tell me that they do not need so much memory. Only normal oscilloscope screen is enough. hehe... after I show what this deep and fast memory really means they are surprised. But still, it helps only some. So do not insert >250MHz with 2 channe use and not >500MHz if one channel in use, then you have high aliasing problem.
But I understand well that name Owon make some interference and it may also make aliasing problem more bad becouse this is Owon.. we can take one 100k memory Agilent and compare aliasing.... my 1980's HP digital scope is clever. It give text warning on the screen about possible aliasing situation. ;)
Here some pictures.
(do not care memory depth becouse with 2ns/div it use ofcourse highest samplerate also with 1k just as with 10M)
1. single channel, fast risetime pulse and 1GS/s (pulse itself risetime is 1,3ns)
2. double channel, fast risetime pulse and 500MS/s (pulse itself risetime is 1,3ns (generator minimum and it is ok))
1 and 2 signal exactly same.
3. double channel, "slow" risetime pulse and 500MS/s (pulse risetime adjusted littlebit slower than
1 and 2 pic. Not know exactly but something like 2-3ns (in this generator this adjusted risetime do not work perfect - need cal or new better generator (this is HP 8161A 100MHz programmable pulse generator with options.))
Here can see that this fast risetime is too fast for 500MS/s (it includes markable amount frequencies over Nyquist and so corners "wobble")
All pictures have same persistence for looking variations enough long time.
Also signal matching to scope is not perfect. (it can not be becouse feed trough 50ohm is connected to reactive input. )
So also signal risetime (nominal 1,3ns) is only in generator output connector if it is matched perfect.
Later I try find scope risetime better with Tektronix fast risetime gen. (around 70ps)
Now I do not find this output adapter connector..
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Here some leak about details - some improvements.
There is more but here only some. Also these may later come obsolete becouse Owon look carefully product and they want do improvements as need for quality, reliability and functionality.
First, all what you have before know about Owon inputs and also some other things construction (early versions) you can forget.
All this https://www.eevblog.com/forum/index.php?topic=4412.msg65047#msg65047 (https://www.eevblog.com/forum/index.php?topic=4412.msg65047#msg65047) is history.
Front end construction have totally changed (circuit not so much) and what I can see with tests, this change is really big improvement also in signal. Also inside RF shield there are full area wall between channels.
Components costs is maybe more high but final is lot of better reliability and better economy in production work. Also it rise reliability. Also now possible service is lot of more easy.
Someone before did not like battery compartment / adapter board mechanical situation (it did not normally touch to this inductor, but now adapter board is lot of better.) . Whole adapter board is totally designed agen.
Also there is not anymore any VGA cable crossing over adapterboard and mainboard. (becouse main board is also partially designed agen and now VGA is also there near Samsung processor and memories and signal go directly on the board layers.) Adapter board have one "smile" mistake. This one capacitor have lot of free room and it can install also now normally but accidentally in production it have still assembled as before.. (on this individual board)
Then encoders. (also there can see one button golden contact area)
Encoders are not best but not at all poorest. They are (in this unit) made by: Ningbo Everbest Electronics & Technology Co., Ltd.
Outside from pictures: They have changed relays. They are now Fujitsu Golden contact relays designed also for RF use.
My opinion without enough knowledge is now that they are better than these older NEC's.(?)
And if someone look some old pictures about Power Unit. As informed before its mechanical construction have changed better.
Also bottom under display and right side of dislpay push buttons circuit board is totally new, now it do not look like prototype. ;)
Absolutely best improvement is this front end. Please Owon, do not give any your designer touch it now without really heavy well argumented reasons.
What they can do is design agen ADC area of PCB so that it follows tightly National ADC08D1000 and ADC08D500 application notes and good other design rules and principles.
(this not bad now - but, good can still be better without growing costs and then it can also competite with higher level scopes in some features (yes it can also today shoot down some old good names (low end models) but if someone do it... after this he break consensus "gravitation" and he fly alone... there are rules that it need tell how good is tektronix or agilent or lecroy - if you do this then you are "good" people.. and all give applause. )
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Relays have also changed for improvement.
Now there is better Fujitsu relays what also may have RF improvement and maybe also they have some other advantage over NEC what was used before.
This all tell that Owon really want do and also do improvements continuously for product reliability/quality, manufacturing, serviceability, and also improve signal handling quality/accuracy. Other dingle dongles are not so important.
Of course improvements wish list may be long. Some things are more iportant than others and weighting these depends usage and people. But first need be real measuring equipment things and after then come makeup like things.
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Some random preliminary samples from testing new improved HW version SDS7102V
(this was not very good and these "waves" on the flatness tell also that signal line matching to scope input was not perfect, but it was done with "normal" poormans practice. (50 ohm feed thru terminator in scope input.)
Generator itself flatness over this whole area is better than +-0.2dBm (checked with Agilent power meter and for more reliability also with accurate condition Rohde&Schwarz spectrum analyzer.)
Sweep time 50s starting from 1MHz ending to 250MHz.
Oscilloscope set for peak detect mode and sweep in scroll mode 5s/div.
Then FFT, sweep from 1MHz to 500MHz
Then 400MHz signal, 5MHz FM modulated with around 90kHz.
First pic signal level 200uVrms (!) and second 40mVrms (same settings in oscilloscope)
(these are around -61dBm and around -15dBm in 50ohm system.
And then sweep 1-100MHz (oscilloscope in peak mode and scroll 5s/div)
Edit: add to bottom last picture. It is Old HW and this special single unit 250MHz peak was better than mutual average what I have seen. It can partially show how oscilloscope front end have also improved and also some improvement in noise level including also bread band "random" noise level.
It is amazing good work from Owon.
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Some trivial toyplay with full speed deep memory.
Now I hope somebody do same (this 150Hz+100MHz) with what ever oscilloscope and also tell oscilloscope price and model. Agilent? Oh and look 100MHz signal aliases, do you want I turn this signal 200MHz... or more. (yes it can, without aliasing)... and horizontal speed is 500us/div.
There is 150Hz square combined with 100MHz sinewave. (just simply with T splitter as combiner)
150Hz square come from old HP8111A function gen and 100MHz come from HP8644B.
Scope run so that whole one phase 150Hz square can look and then pushed stop and then I want find what HF signal is riding on the 150Hz sqw.
Scope still stopped. Then littlebit shifted (becouse I also try with simple timebase "zoom" and forget return timeshift.
Yellow vertical line is 2 set lines for zoom "window". (500us/div base and 2ns/div zoomed 250000:1)
Scope still stopped. Then zoomed, now scope do not use sin(x)/x so shape is not "nice". There it is 100MHz.
Then with this zoom scope run (now also it use sin(x)/x). (notice freq counter 150Hz)
Then more easy.
500us/div and set zoom time 2ns/div (250000:1)
then zoom but also using persistence so that it collects trig jitter if there is. Only what can see is small timing error in trig position well under 0.5ns. In normal mode 2ns/div there is not this.
(and its waveform update speed is also fast with 10M memory if compare example hantek speed with 500k or 1M where you can easy count with eyes how it updates waveform to screen. 1....2.....3...... so Owon 10M is really also usable!
(note: in some picture I forget change probe factor from default 10:1 to 1:1. So channel setting voltage show wrong. (with direct cable it is of course 1:1)
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Hello,
I'm new in the forum.
Afeter reading a lot on Rigol DS1052, Hantek DSO5102B and Owon SDS7102 threads, I finally decided to go on the Owon, and I ordered one with VGA, LAN and battery (I really wanted the battery version).
My first impressions are that the LCD is really fantastic, and although the unit is hevier than I expected is quite portable (I only miss some protection to the LCD similar to the Teks, some cover or something).
The menu is not so bad, I find it usable, and I usually don't need very sofiticated features, so I am quite satisfied with the features.
The VGA output provides 800x600@60Hz (at least that is what my samsung monitor says), and it looks a little noisy and with too much bright (a little washed out), but I tested only a little time and I suppose it can be fixed by setting monitor controls.
My only concern is that the unit looks quite noisy.
Could someone take a look at these pictures and tell me is it is normal?
First one with probe conected to nothing (yes, it's not the best setup, but it looks like picking up more noise than other oscilloscopes I have used).
Second one (probe conected to calibration output, after calibration and probe compensation).
Limiting the bandwith to 20MHz reduces the noise, but still more than I expected.
Is my unit faulty or this is normal?
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Owon (open) inputs are littlebit sensitive for HF becouse they have very low capacitance.
Go to enviroment where is not high EMI. (example not switch mode "energy saving" lamps and not other high level HF EMI sources near oscilloscope and do not connect probe or connect probe with x1 setting and short circuit probe.
Do you have well grounded power line. Compare noise with battery (power cable not connected at all to scope) and then with power line.
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Do test: But first short circuit input. (inside BNC center to GND directly without "antenna") or use example 50ohm BNC terminators if you have. How it change noise if compare open BNC and shorted?
(if have no BNC short it can esy made... take short piece thin wire around 2cm . Fold it half point and then adjust it as Y bottom of Y push in to BNC center and both sides now make connect inside BNC to GND walls.. Wire need be so thin that foldedwire go easy to BNC center hole. Spring effect make it do still enough good contact.
Do default.
Turn off CH2
Turn scope CH1 to 10mV/div DC (with 1x input seting) With short circuited (or terminated with 50 ohm terminator) input BNC and no BW reject.
Turh Acquire mode to peak detect.
Trigger auto (as default)
select lenght 10M
Set horizontal speed to 100ms/div
Save picture.
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Swith 20M BW on and off, how it change noise.
Some amount of noise can always see. This is nominal for digital scopes. (also analog have noise but you can not see it becouse phosphor is slow. Then this mainly thermal noise in digital scope is also together with digitizing noise.. )
If need look continuous signal with digital scope and want noise down, normal practice is use average.
(this is normal for all digital oscilloscope independent of name. many peoples wonders digiltal oscilloscopes (normal) noise becouse they have used analog oscilloscope before.. yes this noise is also there but phosphor CRT itself filter it. If scope have as called fast "phosphor" (or example Tek special fast superexpensve tube, it can show this noise.. specially if turn bright trace out of screen and then look only this noise in dark room... but, digital scope do not "forget" this noise... every "pixel" is fast. If it have sampled, it is also displayed. (on/off) In analog scope one fast random noise spike is so fast and beam is so short time activating phosphor that phosphor can not react so fast.. (in some cases they tell how many meter /s tube can draw so that it can normally be visible. This is good and bad.. also analog scope this brightness variations give information specially if user have lot of experience with it)
(some things are difficult with my 500 word english dictionary)
if someone do not believe this analog scope case... please test it.
Take 10ns pulse what appears every 100ms. Try find it with normal analog scope. Or do single shot. Wathch in dark room brightness full... maybe you see onlu trig led blinks but nothing on the screen. Then keep same pulse... but adkust so that it appears more often... 10ms...1ms...100us... 1us... what time you start seeing this pulse.. ;)
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Thank you very much for your fast response.
I'll try to make the tests this afternoon and post the results.
Undertood your explanation, don't worry about your english, mine is worse for sure.
Just wanted to know if the unit is faulty because in the images posted by you (and others) it looks like the noise is lower, but it may be that I'm in a noisy environment..I'll check this.
Thanks again, and thank you for your comments on this scope. They were really helpful for me to take the decision on the buy on this model.
I'll try to disassemble the battery to check the cells used in case anyone is interested in adding battery capabilities to the scope (it looks like it's difficult to get the battery alone due to courier restrictions).
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I'll try to disassemble the battery to check the cells used in case anyone is interested in adding battery capabilities to the scope (it looks like it's difficult to get the battery alone due to courier restrictions).
Please do NOT.
First, it is one of most powerfull battery still with acceptable price.
It is Lithium Cobalt Oxide polymer battery. INCLUDING electronics! This electronics is just for these cells made by
Hangzhou Wanma High-energy Battery Co., Ltd.
Or also this: http://www.yokuenergy.com/en/intro.asp (http://www.yokuenergy.com/en/intro.asp)
(strange becouse also yoku name exactly same cell number. (is it same company or group? who knows..)
Shipping is NOT problem! But it need do including Hangzhou Wanma safety sheets.
If courier do not understand IATA rules then ... bad courier.
Owon (Fujian Lilliput..) have send these batteries around of world without problems.
Some country of course may have they own rules but how hell they can then get any lithium cells what are in laptop computers, or electric bicycles.
Yest there are rules but also battery alone go under capacity rules on the fly.
It is 60Wh battery and there must not be any problem to send it.
Do not try connect any other battery to Owon. It is build so that part of functionality is battery own electronic inside sealed battery box.
Also if you take battery out. DO NOT make any kind of short circuit or overload. It may damage its electronic.
If you measure empty battery. You can not find voltage or any cuttent if you try load it. Becouse battery out is totally "locked" with its own electronic.
What ever other batteries connected to Owon may permanently damage oscilloscope.
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OK, I though I read somewhere that there were problems to ship the battery if not fitted inside the scope.
Thanks for the advice.
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Made some shots with FFT on my SDS8102 to check whether my device has a line at 250MHz like the 7102. But it hasn't. But when sampling with 2GHz there is a line at 500MHz. So I guess this line is produced only in interleaved mode when both ADC-Parts are running on one channel.
It is the old model with modifications as described
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Hi, I'm a newbie with oscilloscopes and probably I'll buy a 7102, the use would be to debug tube amplifiers.
On Ebay there are a lot of offers ranging from 320 euros up to 400 (and more).
Have someone bought from these resellers? I understand there is no real difference between a 340€ and a 420€ model, they should be the same.
Is there any problem buying directly from a chinese supplier?
Thanks a lot
gmonno (Madrid)
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Both adc blocks have exactly same clock.
When they are combined for one channel use. Clock only inverted and adjusted inside ADC chip itself!
But still it is same clock, not as example Rigol where is separate adcs and separate generated timeshifted clocks. This is totally different interleaving.
Becouse there is just exactly same clock it do not have so much multi ADC interleaved problems.
Also this clever chip have inside chip some kind of selfcal routine so it is quite well balanced also combined mode.
SDS8102 have ADC08D1000 and SDS7102 have ADC08D500. (RuiFeng clones 2001 and 2002)
SDS8102 show 500MHz peak and it is comparable to SDS7102 250MHz peak.
Partially some amount of this peak may also born on the ADC "silicon".
Datastream out from ADC is 250MHz in the 7102 and 500MHz in the 8102 and 8202.
There are I and Q datastreams. Both these streamd are splitted to two 8bit wide databus.
Totally there are 4 pcs 8bit bus. 7102 these each bus are 250MHz and in 8xxx these are 4x500MHz bus.
I have suspect that this noise come somehow from this digital part of ADC. (and if reason is this, then also part of noise can make infection inside chip (this bus driving is hard for ADC if thinking how clean analog side need keep) but first look outside chip and my opinion is that they have not RF isolated enouhg tight analog and digital powerlines to the chip and also GND RF current spikes need handle.
(they are not so easy!)
This noise is NOT any kind of real problem! But of course it is cosmetically littlebit better if it can attenuate some amount. (250MHz in 7102 and 500MHz in 8xxx)
But what I really hope. I hope they do not attenuate these frequencies by FW (filtering digital side... please Owon, do not! You are not Hantek) Becouse I want 100MHz scope what can clearly look signals up to 300-400MHz and even more. ;)
(7102 flatness... <-1dB to 100MHz and <-3dB around 220 - 270MHz (individual units and also differencies what Voltage "band" is in use. (voltage level range is splitted to 3 bands and they have different amplifier/attenuator /and compensation ciruits setting) But quite well for 100MHz oscilloscope.
And this better frequency response and pulse response is ONLY for new improved models what have just short time ago started manufacturing these. (different HW)
-
Hi, I'm a newbie with oscilloscopes and probably I'll buy a 7102, the use would be to debug tube amplifiers.
Have someone bought from these resellers?
Is there any problem buying directly from a chinese supplier?
I would recomment to buy from Your official local dealer (is a little bit more expensive) or directly from Owon which is the same price as the other chinese dealers but including warranty!
The most other chinese dealers won't care if You have any problems with Your device. So be careful - buying cheap may be very expensive!
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From what ever place buy new Owon, there is factory warranty.
But most of sellers do not test/check enything. They sell just this condition what they have get after transport.
Also if they package bad, there is danger for transport damage. This is NOT included factory warrannty!
Also if it is Owon or what ever company who make products there is always posibility that unit have some error/fail. Even if/or factory have done final QC. There is not 100% sure unit is really fully ok. Also failure propability is most high just in new unit... after some ageing if no fail it is more sure it is ok, until there come product lifetime end.. then agen failure rate rise.
Some sellers may do also some kind of pre ageing "burn in" test with all functions test with measurements. Buying from these kind of sellers is absolutely more safe, but still all is statistic. Transport damage is bad and in these case you need trust seller that he take all responsibility. Also for safe it is better to use some good shipping company, DHL, TNT, FeDex etc. Normal postal service is cheap but if not extremely well packaged it is nearly as fishing problems.
Of course customer care is not free. All works need money. Handling risks need some amount of money.
Why there are not so much really good sellers who really also know what they sell and how take care about problems?
It is very easy to sell as dropshipper or nearly as dropshipper.
Risk to get bad unit is small but if it happend it is very sad and may take long time before problems are solved or sometimes buyer only just loose money.
If seller is "small" or "big" it do not meaning nearly anything. Just there are good sellers, exellent sellers and then bad sellers and even fully mad sellers.
Most of sellers do not understan anything what is meanig of "after sales customer care".
This is also difficult and it is nearly so that it can offer only locally.
Pricing is also now just as disturbed becouse there is old versions, versions without VGA, versions without LAN etc... some have now problem to sell old factory versions and it can see in price. Old units in stock.. and nobody buy, what to do. Lower price. This can easy now see in ebay. And also with some other seller who have before buy more big lot to stock becouse reducing shipping cost and get littlebit discount. Now they have old versions in stock, maybe lot of.
From Owon directly... maybe can not get before Christmas... you can look some seller who information that they can get new units after week 02 (2012). They just introduce scopes what they have not at all in stock.
Also remember that wire transfer is not free, you need pay all bank fees, also receiver bank fee. Dependent of buyer bank and location it may be up to tens of USD. Also it need wait this money transfer process. Today afaik there is queye in factory. Buy now, it do not come out next day, maybe next week or next month. Becouse selling trend is fastly rised... and why. Just becouse they are good if compare to competitors in under around USD500 class.
Final: If unit itself have manufacture fail or fails inside warranty time and all things are as stated in rulkes... Owon (Fujian Lilliput... ) is there and they stay behind warranty where ever you buy unit what are manufactured for sellin ion your local area. I have see on the cartons label "EU" and they are not made for local China markets! But do you know what versions some Chinese eBay seller really sell to you.... you ask seller... they may answer. maybe they even not know but still they answer just as chinese seller answer. (if buyer buy, he is good seller, how ever he have talked to seller, what ever he have promised so that buyer buy... and all maybe without any kind of knowledge. maybe some seller it is same selling makeup box or oscilloscope boxes.
Do not take these all words so seriously...
;)
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Hello,
Find some tests run from battery and from AC. With 50Ohm terminator, short-circuit, shorted probe and full/20Mhz BW.
For me it looks like the GND was not conected as open input and terminated input seems to provide the same reading, and te shorted input picks up a little more noise, but it may be OK and the input is just very sensitive.
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I just took mine apart ;-) not a complete teardown - but enough to see the VGA circuit on mine is different than the pictures BlueFlash put on Mikrocontroller
I only have the 3 pin header / cable going to the main boards and quite a few of the chips are missing compared to pictures from BlueFlash.
I do have a very slight noise when turning down brightness on display. But I do not really care right now :-)
Scope looks better built than I expected. I do have a small 500KHz pulse (abut 11mv P2P) when probes are connected to ground. (20.0mvBW/20m limit/500MS/s/2.0us) - but it is the same on both channels. And that seems like what makes my capture lines slightly fuzzy. But I can live with it and I do not have a terminator to put on to test without probes. And it might be an environment issue.
-
Peoples can also think what happends if this picture is 320x240 pixel as example Rigol.
We need remember also that theoretical maximum ADC resolution is 8bit. Vertically absolute maximum levels are 256.
And there is always some thermal and other types of noise, in all units. This is in Agilent, this is in Owon, it is in Rohde&Shcwatz. Some scopes may have different methods for clean cosmetically displayed trace.
Expensive scopes may also have really useful methods for make more accuracy. As we know ADC is sampling always fast.
If samplerate (displayes) is example 10Ms/s there may ne still 1Gs/s. Now how to select what sample is better or maybe use nearly this time point real samples and calculate some kind of time and value weighted virtual sample point to display. Or what ever EE's can find what is good method. But these kind of things need lot of processing power, specially if also real samplerate is high.
Peak detect is more easy. Collect (and littlebit handling) highest samples...
Later I give some kind of simple test pictures from unit what is sure good. (just these open BNC and probe connected and noise. But remember, Owon have nearly 500 vertical pixels and data maximum theoretical vertical resolution is only 256
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First cex:
In your pictures can not see any abnormal or symptoms about problems. Just normal.
(but of course I do not know your enviroment).
After scope is used more than example 100 - 200 hours keep it on least half to whole hour and do selfcalibration so that all connectors are empty and enviroment EMI is normal/low. Always also if temperature is more than 5 Celsius different as last selfcalibration done.
--------
I loose 3 pictures taken with scanning (scroll) mode and peak detect so later these for some kind of refeence.
These pictures have made with sure good perfect normal (new HW) SDS7102V / V2.4.1
All pics acquire is normal mode.
pictures have itself information about some settings so look these.
multiply x1
A: BNC open, normal sampling mode and memory 1k, BW full
B: Same but memory 10M (samplerate rise), BW full
C: Input x10, probe x10, probe adjust made as good as can. Probe connected to scope 1kHz out and GND also.
Memory 10M, note adjusted trig level and signal bottom level (and of course inputs are now DC mode! )
D: same but memory 1k
E: Probe as before: V/div adjusted and also trig level and signal bottom. Look carefully also trig level. Your picture need look nearly same.
F: Probe still connected and probe GND connected to center of probe (test pin) BW limited! Probe head free on the table not near any electronic or electric things.
H: same settings but BW full.
J: This GND wire connected to probe centerpin and opened so that it make nearly O. It is good poormans loop antenna (but with coax cable you can do much more better) Probe still 10x.
This antenna is on the IBM laptop,
M: Same but antenna moved and scope adjusted.
N: still same but "antenna" now different place on the laptop.
last pics just for fun.
With first pictures you can littlebit look if your scope looks around same.
--------
If measure continuous signals and want more accuracy, less noise use average.
If you afraid aliases with lower horizontal speed turn memory maximum. (and turn timebase more fast.
Sometimes good practice is start timebase from highest speed to dow. (many peoples have practice to adjust from low to fast... yes no problem if enough experience for avoid alias issues. Of course this is much more important with low memory scopes what drops dramatically fast sampling speed when go more slov horizontal speeds.
These pics are only for reference if someone think that there is something wrong in noise things in his scope.
(these are made with sure ok SDS7102 and in normal home enviroment without nearly any bad EMI noise, exept this computer just insie 30cm to scope and no any strong RF sources (TV, Radio, etc towers near.
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I will check my unit using your images as a reference.
Thank you so much for your support.
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I will check my unit using your images as a reference.
Thank you so much for your support.
Small differencies are normal. Used probe adjustements and all things tolerances. Also enviroment may affect.
Typical is with 10mV~ range (x1) and PEAK acquisition in use (1k - 10M) and 100ms/div scrolling noise p-p is 3-5mV with OPEN input and BW full.. With BW 20MHz limit it is around half
50 ohm terminator may rise littlebit this noise
If noise is something like double and enviroment have not high EMI level and AC power is clean enough then may suspect scope have some problem.
(sometimes whole lab powerline need filter if house powerline is very dirty. (and this is not related to Owon... but all lab instrumentation)
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Hello to everybody, I'm following with interest this thread.
I have an old philips PM3217, and I'd like to buy a dso.
If I understand correctly the difference between sds7102 and 8102
is only the speed of 2GSps at 1k and 10k memory, is it right?
To rf-loop: how can we identify the new hardware revision?
Is it possible without dismantling the scope?
Will it have some name variant? Or some code accessible
from menu?
I don't want to buy it from no-name ebay seller (300-360euro),
but neither I want to pay more than twice that price here in Italy.
Is there any italian or european reseller with decent prices
(you can also contact in p.m.)?
Thank you all for alll these precious informations!!
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Hello to everybody, I'm following with interest this thread.
I have an old philips PM3217, and I'd like to buy a dso.
If I understand correctly the difference between sds7102 and 8102
is only the speed of 2GSps at 1k and 10k memory, is it right?
To rf-loop: how can we identify the new hardware revision?
Is it possible without dismantling the scope?
Will it have some name variant? Or some code accessible
from menu?
I don't want to buy it from no-name ebay seller (300-360euro),
but neither I want to pay more than twice that price here in Italy.
Is there any italian or european reseller with decent prices
(you can also contact in p.m.)?
Thank you all for alll these precious informations!!
It is still SDS7102. All product versions meet they specifications.
Many manufacturers do many kind of improvements during product.
I have lot of Tektronix service manuals and same for HP. It is more like rule that there are same model but there are many improvements/changes. Then there read that these things are valid to these serial numbers etc. Same in TV's same in cars etc.
Many times users do not need know these. (service need know variations)
This improvement of frequency response over 150MHz area they may delete what ever time becouse it is not specified.
8102, 8202: 100k, 1M and 10M capture memory is limited to max 1GSa/s.
later PM, now busy
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Hello,
I tried to replay your tests.
For A and B (open input) I get almost the same as you, but when I connect the probe I get more noise.
I was unable to get the same shape as you on E, and get more noise on all other tests, but from F and H it looks like I'm picking some kind of interference (maybe a mobile repeater).
If I disconnect the probe GND from center pin the signal on F and H decreases a lot.
I suppose the oscilloscope is OK, but my environment is too noisy (I'm running from battery and no electronic equipment near but don't know what my neighbours have ).
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It looks like the Linux driver is a private project of Michael Murphy, and the project seems pretty dead - no code was ever committed to the svn repository. Probably nothing to do whatsoever with Owon, which means that support will be no help.
You could try contacting Michael: http://sourceforge.net/users/mgmurphy (http://sourceforge.net/users/mgmurphy)
Hi! I thought my ears were burning ;D
The code I wrote is GPL'ed. If anyone wants to make an SVN repository from it then please do.
Credit for obtaining the specs for that range of Owon scope goes to Pavel Cejka. 18 months earlier, Pavel first approached Owon requesting the specs, but was initially rebuffed. Others independently appealed to Owon for the specs but were also refused.
It seemed that Owon wasn't going to budge on this so I set about reverse-engineering the USB transaction protocol used by that range of scopes.
The scope was repeatedly interrogated using the Microsoft Windows software. At the same time, a USB bus sniffer was logging the URBs (USB packets) that flowed between the PC and the scope.*
From examining those URB contents, the transaction protocol was soon understood. It turned out to be a very simple protocol. However, it took much longer to understand the fields in the vectorgram headers.
The Linux driver was eventually published. Almost simultaneously, Owon surprised us by unexpectedly releasing the official specifications. The timing was no coincidence. I guess someone in Owon HQ decided that now the source code for the driver was published, there was no commercial reason to keep the specs private.
So it's surprising that Owon is refusing to release the protocol for its newer range of scopes.
The operating system of the laboratory is Unix, or some flavour of it. Not Microsoft Windows. Refusing to support and acknowledge the *Nix community, a sizeable sector of the market, is a strange business decision.
Plus ca change..
We are currently reverse-engineering the i2c protocol used by the WinChipHead CH341 multi-protocol controller from Nanjing QinHeng Electronics. The CH341 is widely used for a range of applications. We want to develop a Linux driver for a low-cost range of i2c EEPROM programmers. Again, there is only (closed-source) Windows software available for the CH341 and it's Chinese language software too.
To date, QinHeng, the makers of the CH341 have ignored all requests for the specs on that IC. The embedded s/w development we are doing is all in Linux and it's extremely inconvenient to keep a Windows PC running just to burn EEPROMs.
The photos from Blueshark are very interesting. Has anyone examined the flash contents, or a firmware image for the Owon? What embedded operating system are the Owon scopes running? Linux, perchance? If so, where's the GPL'ed source code, please, Owon?
If I can be any help on this project, please email me.
cheers, m
<ee07m060@gmail.com>
* Wireshark now has very good support for capturing USB bus traffic. And by running the Windows s/w for the scope from a VirtualBox guest WinOS running on a Linux host, it's much easier to reverse-engineer a Microsoft Windows USB device driver.
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Today SDS7102 have LAN connection.
For USB and RS232 and file structure Owon have updated "manual" but still it have some errors(?) specially for SDS series. (in this version what I have seen last time) There is explained .bin file header but it have some mistakes .
Of course main thing in Owon is develop itself oscilloscope becouse in mainstream it is stand alone oscilloscope. (yes sometimes communicatin is also more or less important but first in priority is good working stand alone oscilloscope.)
And this, how it works, they have improved, specially front end have improved much better. T
oday SDS7102 is different and better than same SDS before. This improvement/development is they main work. Developing improvements in quality including reliability and functionality -- it is work I hope they put nearly all resources! Then priority level 2. can do these other things. But today I can see that there have been so important need to put all resources to these level 1. improvements that other things have been in state "some day".
Example in short time they have designed whole main board ans adapter board agen and well... they are lot of better. So.. I'm happy that they have not put they capacity to 2. level things yet.
But also I hope they do also these after they have littlebit more "free" time.
But as they now have LAN in this model, I really hope they some day implement also command mode for control unit over LAN.
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It is still SDS7102. All product versions meet they specifications.
Many manufacturers do many kind of improvements during product.
I have lot of Tektronix service manuals and same for HP. It is more like rule that there are same model but there are many improvements/changes. Then there read that these things are valid to these serial numbers etc. Same in TV's same in cars etc.
Many times users do not need know these. (service need know variations)
This improvement of frequency response over 150MHz area they may delete what ever time becouse it is not specified.
8102, 8202: 100k, 1M and 10M capture memory is limited to max 1GSa/s.
later PM, now busy
Ok, I understand the periodic hardware revision process, I was just curious if there are clues
on revision version as serial numbers ranges etc.
Thank you.
Fabio.
-
What I know new versions are later or equal: SDS71021149xxx
(maybe also littlebit before but this I do not know!)
And if there is NO LAN it is nearly sure it is older version.
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Mine 8202 seems like the new version: Serial SDS82021143xxx
Got LAN and different VGA cabling compared to other tear-downs of 8102.
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Another curiosity:
what can be done trought LAN port?
Is it only useful with owon's software?
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Another curiosity:
what can be done trought LAN port?
Is it only useful with owon's software?
Approximately the same as through a USB.
Yes Owon support only useability with Owon software.
Of course LAN and USB are different. Try connect 20 units to teacher computer with USB and then poll students work. With LAN - just simple (not good example). Or what ever multi unit solution can find OR long distance what is not so easy possible with USB.
USB connection is clearly more fast.
For on the table use USB is ok and better.
For long distange or several units polling LAN is better.
Also LAN is free feature, it is not option today. So, if you want or not, it is there - if not want, just not use it. (exept if you buy old stock - and there is not these other more wanted improvements)
VGA is factory option - in other case there is RS232 as default. And LAN is also default. (only with these new improved units).
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Yes Owon support only useability with Owon software.
Of course LAN and USB are different. Try connect 20 units to teacher computer with USB and then poll students work. With LAN - just simple (not good example). Or what ever multi unit solution can find OR long distance what is not so easy possible with USB.
USB connection is clearly more fast.
For on the table use USB is ok and better.
For long distange or several units polling LAN is better.
So I imagine that the dso has it's own ip address and acts
as a normal net device? If so I can connect it to my lan also trough hub
and the pc software need to know the ip-address and see it like any
LAN device?
Or i have to connect directly the dso to pc?
I don't know if I can explain myself... english
isn't my native language.
Also LAN is free feature, it is not option today. So, if you want or not, it is there - if not want, just not use it. (exept if you buy old stock - and there is not these other more wanted improvements)
This is one of the reasons I'm searching for a local and trustable seller :)
Thank you rf-loop and aghp, you are very helpful.
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So I imagine that the dso has it's own ip address and acts
as a normal net device? If so I can connect it to my lan also trough hub
and the pc software need to know the ip-address and see it like any
LAN device?
Or i have to connect directly the dso to pc?
It have fully adjustable: IP addresses, port number and MAC address.
It can connect directly to computer LAN port or as one LAN device to network.
First select LAN menu.
There do all settings if need change default settings.
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SDS71021143xxx, FW v2.3.
December 13 received a shipment. The parcel was sent November 30 from China. EMS mail. VGA, LAN, battery, 3 year warranty. Look at some pictures:
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This is nice information. Now know that also DS7102 1143xxx is "new" version? ( becouse LAN)
What is your version? V4.2.1 ?
Your seller have add "gift"? This one extra BNC cable. Not big value but something.
-
I think I got it from the same seller as I got the same "free gift".
You can e-mail Owon support to get the latest 2.4.1 version. They take some days to answer, but they'll provide a link to an update suitable for your unit (remember to send them the serial number).
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Correction to my last post.
Of course newest version what I know is V2.4.1.
(this is factory installed in product version xxx1149xxx , maybe also to other manufacture lots but this I do not exactly know))
So far ( until otherwise indicated) , if someone wants/needs to upgrade, it should be asked separately from Owon with serial number.
But also newest Version number may differ related to HW installed.
----------------
One thing I hope Owon do improvement. For reliability and avoid problems.
They need use better quality fan!
-
Correction to my last post.
Of course newest version what I know is V2.4.1.
But also newest Version number may differ related to HW installed.
----------------
One thing I hope Owon do improvement. For reliability and avoid problems.
They need use better quality fan!
Mine came with v2.3 installed. Owon provided 2.4.1 patch (fixed version in my previous post).
Don't know about HW, maybe newer serials have improved HW (mine is xxx1143xxx).
Yes, fan is not good. Mine is quite loud... I'm thinking on replacing it.
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Yes, fan is not good. Mine is quite loud... I'm thinking on replacing it.
Ask Owon send new fan. ;)
If many people do this, maybe some day they know. (they do not change it if they do not know it is problem)
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Just wanted to know if the unit is faulty because in the images posted by you (and others) it looks like the noise is lower, but it may be that I'm in a noisy environment..I'll check this.
cex:
About possible noise problem in CH1.
Do next:
Insert 50 ohm terminator to CH1 and CH2 if you have 2 pcs terminator.
set acquire to peak
memory 10k - 10M
speed 10ms/div.
CH1 and CH2 x1, 10mVac,
Both channels on.
Both channels noise need look same amount. (<0.3div (typically 0.15 - 0.2div)
If you have only 1 terminator.
Do test first with CH1 and then same test with CH2.
-------
With FFT:
First do "default" for oscilloscope settings.
Insert terminator to CH1
Set CH1 x1, 10mVac / div
(speed is as is)
go to FFT,
Turn CH1 V/div so that there read 10dB (one click counterclockwise)
Turn CH1 vertical position so that trace bottom is one div up from bottom line.
Turn frequency (horizintal speed)
So that middle is 25MHz.
Can you see small peak just right from center line. (position around 26 MH)
Wait a short time and watch if there is this peak. (maybe example 10dB over random noise or even more)
If you see this peak, wait more and look if there can see sometimes many random peaks both side of this peak and even more high... (these do not appear continuously becouse they need occure just this time when sampled)
If you can not see these and you continuously see only around 1 - 2 div high random noise then you do not have this special problem what is ONLY in first produced units what are these "new generation" improved HW models. Later this problem have solved in Owon.
If have not 50ohm terminator, it is not so easy to see this problem but it can try also with probe.
Set probe 1x, connect probe tip and GND directly together without scope GND wire. (take short part of wire and wound it over probe tip and together with GND surface near probe tip. Put probe on the table directly away from any EMI source.
CH1.
If you can not see clear difference firts in CH1 and CH2 comparison with peak acquire and then also if can not see this 26,6MHz peak on the FFT then you have not this special "problem". FFT you can switct to CH2 and you see there is not this problem or it is just barely visible... after solve CH1 problem it also solve CH2 if it can also see there. (if unit have this problem, typically it can not see in CH2)
If you have this problem please contact seller or directly to Owon for more instructions.
Solution is easy but it need do in Owon accepted service using Owon mechanical part for this small HW EMI problem.
It was extremely nice that very fast Owon solve this problem and solution is enough good. It seems that only part of units suffer this small noise problem. Now in manufacturing there is this solution in use and not problem in new units now.
I do not know how before but this I know sure that units what have serial SDS71021152xxx or later they do not have this problem.
Owon have been very good and responsible and helpful for quickly solve this problem.
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I'll check... thank you.
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I think these images shows the problem
-
kaz911:
This scope what made these pictures have exactly this problem.
It need Owon service (other way warranty void if something happend)
Take contact to Owon service.
This problem is fully and simply solved in Owon and also it have changed in production.
Some scopes what are made just after new improved model start in production may have this problem.
Officially it need take contact Owon dealer or directly to Owon for get directives how to do.
(scope have warranty and Owon is responsible for this!)
Repair/mod itself is extremely simple. In theory solution is straightforward ans simple and also in practice mod itself is really simple. (no need solder etc but need small new mechanical part...). But real danger is dismantling and handling these inside things... it can really easy damage with wrong hadling or/and wrong opening etc..
If you have seen someone have published "service"manual, also it is obsolete!
(if you do not care warranty and if you have sure enough experiance and "skills" and want "DIY" repair it I can give help by PM but just these days I'm extremely busy.)
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It is my new scope. :-( and I did have a feeling / rant about 2 weeks ago about to much noise on Ch1 when I got it. But I did not have any terminators to eliminate probe induced noise. But I got my terminators yesterday and found them.
That is from my SDS8202 SW version 1.3. So that has the problems as well. I can repair it myself if I get the parts.
I also have a slightly defective Ch1 Horizontal Position Pot that "moves" the wrong way dependent on how I put pressure on the knob. (Normal operation usage - not excessive) - fx turning clockwise should lift Horizontal Position - but sometimes it lowers the Horizontal Position. Ch2 Horizontal Position works fine.
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Hello,
I tested on my scope and I didn't find any significant difference between channels 1 and 2 (I only found one 50 ohm terminator, so could not test both channels at the same time).
For the FFT I also could not say if the spike at 26Mhz is bigger than other spikes.
This is the image for CH1 with the highest spike I saw.
I'll try to repeat the tests with two termianators just in case it make any difference.
In case I had the problem I'm really reluctant to send the scope back to China, so I'll be grateful if you could provide instructions to fix it by myself.
By the way, my scope has serial SDS71021143xxx... do Owon know all the serials that have this issue?
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cex:
Look kaz911 pictures. If you find this, you have this issue. If not, then forget it. ;)
Also you can test more using example persistence what may give better way to find if these spikes occurs (becouse sometimes these spikes are rare but still they may be more high than this 26.7MHz spike. With persistence sreen do not forget fast rare peaks.
Terminator on CH1, FFT source CH1
Turn display persistence to infinite. So it remember on the screen if there have been spikes.
Also you can zoom so that 25MHz is center but zoomed. (example 2x or 5x zoom)
Other settings same. (and Acquire normal - not average)
Using display persistence it is more easy to imagine what is random and what is not. Leave it on example some minutes.
In display button sub menu "persistence" you can "clear" collected persistence if want.
With 5mV/div base noise is around 2div. (10dB div)
With 10mV/div base noise is around 1.5div
---------
Your picture looks like if there is this problem it is very small.
---------
I do not know if they know exactly all serials.
(I have seen same production lot and some scope have problem, some do not (same construction exactly) - no one know why. (there may be small differencies in parts tolerances what may make some unit more sensitive to this problem and maybe it is reason also why this can happend after tests before production)
In real life there is many things what may affect littlebit to this situation, how this RF field level is inside scope and how this RF travel scope inside parts/blocks and what road. Solution (now) is not shut off this RF EMI inside scope but solution is eliminate one "bridge" where it travel from block to other block and finally to very sensitive point inside CH1 "block".
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We are selling the OWON SDS7102 for $549.95 in our amazon.com store. Shipped by amazon.
http://www.amazon.com/SDS7102-Digital-Storage-Oscilloscope-2-channel/dp/B006G54K3G/ref=sr_1_1?ie=UTF8&qid=1324414326&sr=8-1 (http://www.amazon.com/SDS7102-Digital-Storage-Oscilloscope-2-channel/dp/B006G54K3G/ref=sr_1_1?ie=UTF8&qid=1324414326&sr=8-1)
Will be adding more models the first week of January 2012 (SDS8102, SDS8202, HDS, PDS).
NKC Electronics
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I repeated the tests with FFT and persistence.
First an image of noise on both channels, with both inputs left open (using 50ohm terminator increases the amplitude a bit, but it looks more or less the same. As I only have one terminator available now I tested with both channels open). It looks like both channels behave the same way.
For the FFT, I'm not sure if I have the problem. I can't see a higher spike at 26.7MHz, but looks like channel 1 have several spikes over the spectrum, and channel 2 have more more spikes at lower frequencies than CH1 (both measures with 50ohm terminator).
I have also noticed that, with the 50ohm terminator plugged, if I touch the terminator metal case with my hand the scope picks up a lot more noise both on FFT and normal display... this doesn't seem to be OK as the BNC case is connected to GND, am I loosing something? (The same happens if I touch the input GND with nothing connected, but in this case I thought the input can pick up some noise from my hand).
Reviewing your other post on new sds7102 series, you say the problem is related to the metallic hexagonal "tower" on input stage... is the problem fixed by replacing that tower with a non-metallic one?
Regards.
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Ok,
please give me two images.
Do default.
Wait half hour.
Do selfcal.
Shut off scope and just without waiting agen on.
Keep all defaults exept next:
(for next: IF you have battery for scope, use it and tell if it was used)
Set only CH1 use. 50ohm terminator to BNC.
(sidenote: do not touch GND or BNC terminator when doing this test. Specially if enviroment have high RF field it is nearly same if it go trough GND or center pin (GND is other part of signal and center is other part. Both these are as wires. (it is not easy imagine that GND is "wire" becouse it is thick, but thick or thin, it is signal path what have reactance. It is inductance just as all wires. For RF nothing is pure resistance. If there go RF current it go and it do its work... This is why we many times in lab are worry about EMI clean enviroment. And now in this case I do not know exactly so also this need suspect. Shut off all RF noise sources near scope or connected same powerline with oscilloscope... specially all switch mode equipments as "green" energy saving lamps, and equipments what may produce high EMI. If suspect enviroment EMI, go to "clean" place for do this test. I hope you have not near area any high RF power TV, radio FM,LW,MW,SW commercial radio stations.)
probe: x1
2mV/div
10ms/div
mode: peak
--> image
then
CH1 with 50 ohm terminator
2mV/div
10us/div
Set persistence 2 second
--> image
also if want I can try look what it show if you touch terminator (in time domain mode and also FFT if need.)
But now also need be careful with FFT frequencies. If example sampling speed is 100MSa/s there is Nyquist freq 50MHz. Now also (Owon) scale is 0-50MHz and this 25MHz is center.
What happend if there go inside example 90MHz RF... or 110MHz or example 290MHz?
Well... there can see 10MHz peak. This is not Owon. This is of course FFT fundamentals. This is not professional FFT analyzator whre may be built in extremely expensive automatically tuned Nyquist freq sharp and deep low pass filter on the analog side. (It can not do after ADC with digital signal handling) This kind of good filter may cost maybe tens of Owon price... ;)
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Sorry, I could not perform the tests yesterday.
Will try and post the results this evening.
Just one question, on test number 2 I shall change from 10ms/div to 10us/div, or it is a typo and I shall only change persistence?
Thank you.
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Sorry, I could not perform the tests yesterday.
Will try and post the results this evening.
Just one question, on test number 2 I shall change from 10ms/div to 10us/div, or it is a typo and I shall only change persistence?
Thank you.
to 10us and there persistence.
no persitence with 10ms
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Looks like my unit will be going back to be serviced/updated.
Also, noise on my unit only appears on channel one.
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to 10us and there persistence.
no persitence with 10ms
Here my results... it looks like the unit is picking up some interference.
I have a broadcast (TV+Radio) not too far away (maybe 5 Km).
I'll try again at my office that is on another location.
The test were performed running from battery with power cable unplugged from unit.
From the post by ForceFed I see I do not have the same problem (or at least not so huge).
-
ForceFed:
Your unit have this problem and it is very clear. It absolutely sure have this problem with full level.
This unit need "repair". It need this small change what Owon use now in production.
cex:
It looks like your unit have this problem but quite small level. But clearly it is there.
This is nearly as "borderline". If you can live with it, it do not affect normal use so much.
(This is my opinion after I have look all pictures and explanations.)
If it is problem, it can "repair". In this case it need do same change what Owon use now in production.
As you before tell you have problem to send it to Owon China or some other place Owon service.
If this is case and you have enough experience and skill you can do it. There is some things what is good to know how it is maybe most easy to do without extra "try and learn" turns.
But whole oscilloscope need dismantle nearly fully and there are some things what may easy damage it, also it really need good practice with ESD safety. Also there are some easy fragile things, but also - this is not missile or moon rocket.. .
Repair itself is very simple (and more simple if you have this small part from Owon - but also it can solve with simple "DIY" solution. More problem is open and dismantle it without damages so that it can do.
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I think that I can live with it, but it would be nice to have it fixed.
I won't be sending it back to China if I can avoid it (Spanish customs is a nightmare and I will surely have to pay again despite the fact the equipment is sent back for repairment, and I also don't have any other oscilloscope at home for the meantime). On the other hand, there's no official Owon technical service in Spain (as far as I know).
I have access to an ESD safe area at work, and I'm trained in handling electronic equipment. I have also access to professional soldering/desoldering equipment, so it would be nice if you could provide instructions so I can evaluate if it is worth to take the risk.
Have you got a photograph of the Owon mechanical part required? Can it be replicated easily?
Anyway I'll contact Owon and the Chinese seller for that part (have you got a reference?) and for a more silent fan (the current one is quite annoying if you are in a silent environment).
Thank you very much for your support on this issue.
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I think that I can live with it, but it would be nice to have it fixed.
I won't be sending it back to China if I can avoid it (Spanish customs is a nightmare and I will surely have to pay again despite the fact the equipment is sent back for repairment, and I also don't have any other oscilloscope at home for the meantime). On the other hand, there's no official Owon technical service in Spain (as far as I know).
I have access to an ESD safe area at work, and I'm trained in handling electronic equipment. I have also access to professional soldering/desoldering equipment, so it would be nice if you could provide instructions so I can evaluate if it is worth to take the risk.
Have you got a photograph of the Owon mechanical part required? Can it be replicated easily?
Anyway I'll contact Owon and the Chinese seller for that part (have you got a reference?) and for a more silent fan (the current one is quite annoying if you are in a silent environment).
Thank you very much for your support on this issue.
Ok.
I will later collect some pics and guide how it can do also if do not have this Owon part.
But please ask first Owon. You can also tell that you have experience and skill to do it if they accept (in this case you may keep warranty status still valid) Then if they send this small part to you its ok... but also you can do (maybe better) it your self.
Later, inside some days I can collect some pictures and instructions how to do it. (with DIY part or with Owon part)
Then I send this info with PM.
But try ask first Owon.
You can tell that you have new improved SDS7102 with LAN (give serial number to Owon also) and it have CH1 noise problem. (tell in this letter that your problem is well known inside Owon and you want now know how you can get it repaired. You can not accept this kind of error in product.)
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Hi, guys!
I want to buy the SDS7102. But I understand that it can't operate with equivalent frequency (I didn't found it in user manual). Is it necessary option for periodical signals? How often is it used?
Thank you!
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Ok.
I will later collect some pics and guide how it can do also if do not have this Owon part.
But please ask first Owon. You can also tell that you have experience and skill to do it if they accept (in this case you may keep warranty status still valid) Then if they send this small part to you its ok... but also you can do (maybe better) it your self.
Later, inside some days I can collect some pictures and instructions how to do it. (with DIY part or with Owon part)
Then I send this info with PM.
But try ask first Owon.
You can tell that you have new improved SDS7102 with LAN (give serial number to Owon also) and it have CH1 noise problem. (tell in this letter that your problem is well known inside Owon and you want now know how you can get it repaired. You can not accept this kind of error in product.)
I have just sent an email asking for the required part as well as for a replacement for the fan.
I will let you know when they respond.
Thank you.
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Anybody know a reputable seller in the US that has the latest version SDS7102-V without the noise issue?
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Anybody know a reputable seller in the US that has the latest version SDS7102-V without the noise issue?
This issue is not in all "improved" version. It maybe (agen: maybe) in units what have serial SDS71021143xxx up to SDS71021149xxx (these may have this issue... (with my own eyes I know some serial prefixes 1149 and these some units have, some do not have or have only very small level this problem)
I do not know what serial prefix they start this improved version what also have LAN as default.
If serial is SDS71021152xxx or later it do not have at all this issue (here they sure change it in manufacturing... also maybe littlebit before. (maybe somewhere between 1149xxx - 1152000
Also old construction do not have this issue. (in this first generation version whole front end construction is different) I do not know what serial number it exactly change.
(also repair is "easy". No need solder anything etc work for circuits. There need only isolate one conductive road (on the GND) where this noise RF travel inside scope to wrong area. One small metal part need change to not conductive material.)
Disclaimer: This is not official information! Only my own logical mutual thinking together what I have really also see with my own eyes in some units.
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Anybody know a reputable seller in the US that has the latest version SDS7102-V without the noise issue?
The units we are selling on amazon were received in the US on December 12th, 2011 and they have the LAN interface by default. We are offering amazon return policy on these units.
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Hello everybody, 23 dec. i received this scope from aghp,
perfect seller, he explained me all that said rf-loop before
about different versions etc. The scope with battery arrived
with perfect package (italian-post-proof :) ),
the serial is SDS71021149xxx it has LAN and VGA out.
The about dialog show Version V2.4.1.
Now I'm trying do decode bin file format, It's a pain to
handle the huge csv file.
Has anybody tried to understand the owon bin file?
There is an owon document that explains:
OWON_Oscilloscope_PC_Guidance_Manual,
this is the map I understood so far.
From the file start, big endian.
Has anybody worked with it?
Added the png version of the pdf.
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..... big endian.
Has anybody worked with it?
Thank you about feedback.
Now I can see that I have made small mistake.
I'm so sorry about this hassle. Mistake is fully mine.
In "Guidance" manual it is right: "Little-Endian",
but least in one my email I have accidentally write wrong as "Big-Endian".
It seems that my memory is bad.
If someone need more explanation it can find example here:
Some explanation about "Big Endian" and "Little Endian". (http://www.cs.umass.edu/~verts/cs32/endian.html)
Just byte order if data need more than one byte.
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aghp,
thank you for your help, don't worry you havent' made mistakes,
or at least the "big endian" in your email gone unnoticed by me,
and I made the same mistake writing the previous message here.
The endianess is something i confuse often :)
The bin file is little endian, and I'm reading it as little endian.
I can decode the file with a test script, but there are still
fields that are not clear, when I have more time I'll test better
the various settings. Another thing is that when I save
the file from the dso on 4gb usb key (formatted Fat32 4k cluster)
sometime that the file doesn't show on pc, and the disk shows
some errors in scandisk.
In attachment une of the decoding tests with a python script.
The voltage seems correct, the timebase is unimplemented yet.
The red dotted lines are the clipping levels.
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But please ask first Owon. You can also tell that you have experience and skill to do it if they accept (in this case you may keep warranty status still valid) Then if they send this small part to you its ok... but also you can do (maybe better) it your self.
Later, inside some days I can collect some pictures and instructions how to do it. (with DIY part or with Owon part)
Then I send this info with PM.
But try ask first Owon.
You can tell that you have new improved SDS7102 with LAN (give serial number to Owon also) and it have CH1 noise problem. (tell in this letter that your problem is well known inside Owon and you want now know how you can get it repaired. You can not accept this kind of error in product.)
Owon has contacted me offering to send me the spare part required and a new fan.
Will let you know when I receive them.
Until the moment, they had a great response. It's good to know that the product is well supported by the manufacturer.
Regards.
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Someone have share in internet Owon "service manual V1.0".
This manual is highly obsolete for new versions and specially for new 4Q2011 improved HW versions.
There are even pictures what are maybe made before real production have started?
(example FAN is installed different and wrong side of Z base plate).
It is different in versions before front end improvements and after improvements. maybe some pictures are from prototype phase?
Also least today with improved versions oscilloscope disassembly and assembly work is littlebit different.
Main changes:
Power unit (different D4 assembly and some minor differencies) new version is 1.5
Adapter board: Totally different and also no anymore VGA cable (also dimensions have changed)
Main board: Totally different: Added LAN, VGA chip now on the main board (optionally), front end construction totally different, connection to front panel board is different. Before direct pin connector, now flat cable.
Front panel board, different becouse connection to mainboard have changed.
F1-F5 - H1-H5 key boards changed (now only one board)
There maybe coming some pictures and some (unofficial) guide for new improved model for assembly and disassembly and there is pictures and text material for this but they are not ready and I have not any rights for any part of this material what I have seen.
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Owon has contacted me offering to send me the spare part required and a new fan.
Will let you know when I receive them.
Great, please take a few shots of those spare part and share it here once you got it.
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This I can share.
There is also DIY version what is just more easy.
(5 - 5.5mm nylon rod. Exactly 14.9 - 15.0 mm lenght. Drill center both ends diameter ~2mm hole (depends what screw you use) around 5mm deep.
You need this nylon part and 2 pcs 6mm long screw where is just diameter 2.5 - 3mm thread (sparse thread).
(take old metal pillar out and install this)
It isolate inside front end near CH1 sensitive parts GND so that RF noise in Z base plate can not pollute this sensitive GND area with RF noise. There is more long and nice explanation but this is enough here.)
Owon original nylon pillar is more thick than original metal pillar.
If factory have installed nylon pillar there is no problem with hole what is in RF shield.
If retrofit this pillar it may need light mechanical fix so that it can install. (if RF shield hole is not exactly centered.
Front side and back side RF shield need watch that do not push too down so that these shield make short circuit inside parts. They are very close. DO NOT tru desolder RF shields if you do not have extremely good soldering tools as class "Metcal" or compatible. many poor soldering tools need use too hot temperature and only it can destroy board. It need really lot of heating power!
Front side RF shield need this plastic isolation what have glued over it.
Before you assemble all back inspect front panel board just under this RF shield can area and if need cut some wires more short if they have contacted to this insulator plastic.
In all work use good ESD protection! (all know that unit may work after ESD but it may suddenly stop working later, after weeks, after months - and it is not magic, it is physic)
But I "believe" there is quite soon coming better disassembly and assembly guide for these more new versions.
Here in picture is Original Owon factory part!
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My scope finally arrived today from Ebay Seller eeLAB (AideTek)
I emailed to make sure this was an updated model:
New OWON 100Mhz Oscilloscope SDS7102 1G/s large 8" LCD LAN VGA battery included
Firmware Version 2.5.1 Serial: SDS71021152xxx
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Last night I ordered the same from Aidetek also, although under the smtzone ebay name. They seem to have 3-4 names on ebay.
I put a note and emailed them to make sure the serial number is SDS71021152xxx or later.
Hopefully they can make it happen. I'll post back the version I get.
They have a good deal with the battery included.
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Yeah mine was $513 shipped. The response I got is that the shipment they received the week of the 23rd was all the latest updated from China.
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Nice, mine was the same price. Hopefully mine's as uo to date as yours.
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Afaik, SDS710211xxzzz
11 may bee year, xx is manufacture "week" or better say "some kind of lot number" becouse How it can be week 52 if they are made on week 50 (this I know exactly... I have seen ...52... and it have made just ending of w49 or just beginning of w50 exactly (or weekend w49/50), in Owon factory).
zzz is number in this "lot"
Itself they do not mean anything meaningfull to end user. They can think just as serial number.
We can look tektronix serial number, Agilent (HP) serial numbers etc.
Somewhere in 4Q2011 they change this hardware version and 1149xxx - 1152xxx HW is same. (they are these "improved" versions.) Original first improved HW version maybe started somewhere between 1137xxx - 1149xxx who knows this?
No one know how to read oscilloscope displayed version number.
What information in version number tell if some have really changed example in UI or features?
If FW itself is functionally same exept options included to UI, example there is RS232 or VGA this version is different?
If there is not VGA there can not see VGA set in menu. If there is not RS232 you can not find anything for RS232 in UI menu. So FW is "different". ;)
Also example I have made upgrade to V2.1.1 but still it is V2.1.1. (nice?)
I have no any perfect knowledge what is exactly serial number where they change to this "original first improved HW version". Also I do not know exact serial where they change to "patched improved HW version". Maybe there is not exactly serial number as "before and after" becouse it is possible that they have also made this patch inside Owon before shipping to some lot of ready scopes just after they know this problem and before these have shipped out.
Only difference I can see is CH1 possible noise problem in "original first improved HW version" This patch after this issue is only cut one RF noise "road" inside oscilloscope so that one metal pillar from Z-plate to main board is changed to nylon pillar so that Z-baseplate noise can not travel to sensitive circuits inside CH1 front end RF shielded block.
I have not get any changelog from Owon and not explanation about "version" numbering.
If take V2.4.1 what is 2 meaning, what is 4 meaning, what is 1 meaning.
How there is implemented factory options example VGA / RS232.
Also if someone know what are these Aktacom (=Owon) versions?
How peoples can know what Agilent serial numbers have HW minor or higher level changes? ;)
I go to service parts store for my car. Sometimes they only ask year model but many many times they ask car "serail number" and then they look some database that just this serial number have this rare water pump... and and I need some O-ring oh... what is your car serial number..
But when I buy my car, I have not been interest what serial number I get. Do I need?
Why there is "version" number and why it is important if we do not know anything how to read it and what it is meaning?
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My scope finally arrived today from Ebay Seller eeLAB (AideTek)
I emailed to make sure this was an updated model:
New OWON 100Mhz Oscilloscope SDS7102 1G/s large 8" LCD LAN VGA battery included
Firmware Version 2.5.1 Serial: SDS71021152xxx
Becouse I have seen SDS71021152xxx (VGA + LAN) and in factory directed to European Union (EU) area. What I have seen there is V2.4.1
Now I hope you can confirm that this version number is right.
If it is not typemistake then I ask you list all languages what are istalled in FW.
(I hope to find some explanation for this version numbering hassle in Owon)
In some manuals there reads:
Chinese, English, Others
is it possible that this "Others" vary in different area of world? And this may also then affect version number?
(Of course factory have localised these to different part of world becouse different powerconnectors but is it possible that they do also other kind of localisation? )
Later I visit place where I can see nearly end of year made 2.4.1 EU versions, now I do not remember this language set.
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Itself they do not mean anything meaningfull to end user. They can think just as serial number.
We can look tektronix serial number, Agilent (HP) serial numbers etc.
How peoples can know what Agilent serial numbers have HW minor or higher level changes? ;)
HP used to change the serial number prefix for significant hardware changes, eg. from 2015A... to 2201A... . So a change like this would have been immediately obious from the serial number. I believe Agilent does the same, but I don't have any Agilent equipment on hand to check.
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Hi
I've encountered another odd problem with my SDS7102 oscilloscope. When I was moving some of my stuff around I had it disconnected from the power gird over the night and when I powered it up again it wouldnt boot, and a red light instead of the green one was present. After a while in standby-mode the red light turns green, and when I turn it on the green turns red. When waiting even longer it'll boot up correctly but the settings are lost. (Measurements etc.)
Owon SDS7102 Oscilloscope, odd behaviour (https://www.youtube.com/watch?v=e4iRH-DENBw#)
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There other thread you can find link to Illustrated Guide pdf for disassemble, fix and assemble related to CH1 possible noise issue in some improved SDS7102 versions.
https://www.eevblog.com/forum/index.php?topic=5883.0 (https://www.eevblog.com/forum/index.php?topic=5883.0)
There you find link
-aghp
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We are running a New Year sale on the SD7102-V in Amazon.com for $500.
http://www.amazon.com/SDS7102-Digital-Storage-Oscilloscope-2-channel/dp/B006G54K3G/ref=sr_1_2?ie=UTF8&qid=1325461707&sr=8-2 (http://www.amazon.com/SDS7102-Digital-Storage-Oscilloscope-2-channel/dp/B006G54K3G/ref=sr_1_2?ie=UTF8&qid=1325461707&sr=8-2)
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We are running a New Year sale on the SD7102-V in Amazon.com for $500.
http://www.amazon.com/SDS7102-Digital-Storage-Oscilloscope-2-channel/dp/B006G54K3G/ref=sr_1_2?ie=UTF8&qid=1325461707&sr=8-2 (http://www.amazon.com/SDS7102-Digital-Storage-Oscilloscope-2-channel/dp/B006G54K3G/ref=sr_1_2?ie=UTF8&qid=1325461707&sr=8-2)
This may be just too complicated, but the forum have the "Buy / Sell / Wanted" section. We all know that this is a very difficult and will certainly require a lot of studying. But it need hardly the highest level of qualification, usually in the sheer ability to read is enough. Even many foreign language people succeed with this.
https://www.eevblog.com/forum/index.php?board=7.0 (https://www.eevblog.com/forum/index.php?board=7.0)
:)
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Hi all,
I need a scope. I researched on the net and found marmad's OWON SDS7102 review and this topic. I have read topic, but not fully understand revision history of this model. how many times revised this product and whichever is last version?
I will buy SDS7102 from ebay, but i afraid to be have a defected or old revision copy. I search from ebay and found two model of SDS7102. "SDS7102" and "SDS7102-v". is -v manufacturer's labeled new official name? or added by seller?
I want new improved and faultless (fan noise, ch1 noise, bad bandwith, bad designed pcb for RF signal etc.) hardware revision SDS7102. How can i make sure that, or which seller to can be trusty about this?
(sorry for my bad english.)
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Buying from a reputable dealer, not some random ebay vendor, might help.
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SDS7102 is without VGA output connector. (in this case there may be old RS232. It is fectory default.
SDS7102V is with VGA output. (SVGA 800x600)
Old version is just as good as it was before they make some improvement. It was also amazing good in this price class.
New improved version is better.
How to regognize new improved version?
In this new version LAN is factory default!
If there is no LAN it is nearly exactly sure it is not this "new" version.
Short time after Owon start "new" version there was CH1 noise problem in some units.
This is reviewed here. There is also now Illustrated Guide for repair it. It is fully mechanical work! No need any solder work.
Solution is official Owon solution what they use now in production. Guide is not Owon official material, it is quickly (and littlebit loose) made by me becouse Owon (public) service manua is, how I can say, just for fun. Not real professional service manual and also today it is extremely obsolete.
If unit have serial prefix SDS71021149xxx or below (but still new improved version) it perhaps sometimes have this issue. If unit srerial prefix is SDS71021152xxx it do not have this issue. In other way these are same.
Every manufacturer what I know, Tektronix, Agilent, Rohde&Schwarz etc.. They all have stated that they develop all times equipments and they things may change without any pre information and if I buy, how I know? Owon is not alone...
What is bad BW.
Original Owon SDS7102 is 100MHz oscilloscope. BW - 3dB point is well over 100MHz (around 150MHz) . Some other may sell these as 150MHz oscilloscope. Is it bad BW????
New improved version is also specified (named) for 100MHz. There do not need be more!
But there is Owon "gift" for "hackers" and they give free factory "hack" so that peoples do not need try and break working units... it is (today) typically around 220 - 260MHz -3dB point if compare 1MHz level and using 6 div p-p sinusoidal signal.
Rising time was originally good. In this class extremely good.
Now it is even better. Typically well under 2ns.
Who tell that Original version BW is bad he do not know what he is talking, exept if he is talking too wide BW. Maybe there is some misunderstooding about what is what?
What I can tell is that if there is something wrong in BW it is "too good".
In some cases it may give some aliasing issues if user do not be careful or if he do not understand at all these basics of digital oscilloscopes. Specially if use 2 channel same time. It have just -3dB point frequency equal or near with Nyquist frequency.
But also many other oscilloscopes have this more bad in practice - becouse lack of high speed memory so they need drop sampling rate fast when go to more low horizontal speeds.
So, this CH1 noise issue is easy case. And well... there is lot of user who never find it alone without these information here.
I'm sure if I make this issue to one oscilloscope and give it to 100 average entry level hobby users without they know anything about issue (just like never heard)... maybe 5% find it and think... "well this is chinese cheap oscilloscope and maybe it is feature". Rest 95 do not maybe see never anything. Of course peoples now see it becouse this have introduced here. All times these kind of issues "overheat". Same as FAN noise issues.Who think that 1000 peoples come here for tell that they do NOT have extra FAN noise. But if there is 10 noise cases you maybe find half of them here. This is typical in all cases today, Not only with oscilloscopes.
One person have talk he find Agilent some RF noise problem... well whole world know that Agilent oscoilloscopes have this problem and are nearly as paranoic about it. Where are these hundreds or thousands who are happy?
I have looked (long time ago) Rigol. If I compare Rigol FAN noise (I hope they are more silent today) and Owon normal FAN noise. Owon is like cat walking and Rigol is like chinese Shenyang J-15 taking up.
Owon drive 12V FAN with littlebit over 8V (typical).
If seller test carefully what he sell there can avoid most of issues and also still very rare FAN audio noise problems.
Also I have seen some FAN what keep some random noise as they are new, some of these are silent after 10-20 hour run. (yes it may also happend, I have seen it.)
If FAN really is or go bad, it is not end of world, Just simple repair work and that's it. It takes just 10 - 12 minutes and this kind of fan is cheap. (I know many peoples think why this is not better. If start this kind of thinking there is 100 parts what can be "littlebit" more quality and price. Well, where is then "entry level" price class?
But FAN is also critical component and I really hope Owon change FAN model or manufacturer ans model.
Just time ago they change all cheap relays inside scope to better (and more expensive).
LAN, it propably is new version
If not LAN, nearly sure it is old (but still amazing good oscilloscope).
V (VGA) it can be in old and new.
CH1 noise: In some first manufacturing lots of new version
FAN audio noise. THis is lottery. Every 1 of 50 "win" and Owon make RMA or send FAN to you. (if problem is real probleml... and not "I do not like it becouse it can theoretically be more silent.")
Of course from these sellers who test really what they sell, propability to get bad FAN is also more low. If lamp is ok when I shut off it... how I know it lights when I next time power on it. This is still true, what ever kind of tests who ever make. Seller, manufacturer, component manufacturer etc.
After then come after sales customer care. Who believe it is free dinner?
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Just got mine today from ebay's smtzone (AideTek).
The info is the same as Deneteus:
Firmware Version 2.5.1 Serial: SDS71021152xxx
I'm not sure if this was my fault, but I got a strong burning smell followed by a shut down. I had to turn off both switches and it then powered back on fine.
What caused this is:
I was following the manual on probe compensation which worked fine, then I did the self calibrate. Right after that I connected the probe back on the compensation output and the screen went a bit crazy, then blank, then it shut down. I restarted and the bad smell came on strong for a bit and then has since been decreasing. I guess the smell could have started right when it shut down.
It seems to be working ok now though.
This is my first scope so I don't know what's normal yet. After reading the manual, I'm going to go through online tutorials.
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"Firmware Version 2.5.1 Serial: SDS71021152xxx"
Please can you list what languages there is selectable?
If you do not regognize some language just list ???
I try still find what is difference in
Version 2.5.1 Serial: SDS71021152xxx
Version 2.4.1 Serial: SDS71021152xxx
(becouse they are same manufacturing lot but all 2.5.1 what I have heard are still outside of EU and I know big parcels are labeled in factory "EU")
So it is also possible there is different languages. Also in Owon specs, "Chinese, English, Others"
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I'm not sure if this was my fault, but I got a strong burning smell followed by a shut down. I had to turn off both switches and it then powered back on fine.
This is my first scope so I don't know what's normal yet. After reading the manual, I'm going to go through online tutorials.
No, that is not normal....
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Owon has contacted me offering to send me the spare part required and a new fan.
Will let you know when I receive them.
Great, please take a few shots of those spare part and share it here once you got it.
Received the parts yesterday.
Here are a couple of images:
(http://i174.photobucket.com/albums/w85/cex123/sds7102_spacer.jpg)
(http://i174.photobucket.com/albums/w85/cex123/IMAGE_201.jpg)
The spacer seems to be an standard nylon hexagonal spacer.
For the fan I don't know if this one will make less noise until I replace it. It is 60mmx60mmx10mm in size.
Regards.
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cex:
maybe you have seen this Illustrated Guide for Assembly and Disassembly Owon SDS improved version (http://www.box.com/s/pvg1dqtdonx192p4os0m)
In very old "first version SDS" Owon made service manual example Fan assembly is different. (on the opposite side of the metal plate)
It can maybe find somewhere internet. Some people have published it (Without the Owon approval?)
In this Guide is not information for FAN becouse it is only partial guide for this model.
This your picture is exactly same FAN what Owon use in production (until they change it).
It is standard 60mm/10mm 12Vdc Fan. And as all see in label it have cheapest possible sliding bearing.
This Fan need handle carefully becouse its bearing is "not best possible".
Also sometimes some Fan keep some extra noise just after they are new. I have seen lot of these and most of "new noisy" are ok after 20 - 40 hours power on (if there is some small random noise). But not all. Personally as seller I test all units before sell using 72 hour cycled "burn in" run using also different temperatures. I have find only one really bad Fan. I suppose it was damaged in factory assembly maybe just becouse some loose worker. (bearing of fan was damaged)
Totally I have changed 3 fan (all before selling) becouse there was also two what I can not accept.
Normally this fan is not real problem. But it need be also ok in every single unit! Least it need be ok before send to end user!
Also I have asked Owon develop more accuracy to final QC. In this price class do not need be perfectionist but as long as better and more accurate quality control do not cost anything it is wise to do. It do not need more money. It need teaching. All China companies need learn quality thinking and not only thinking. It is teaching/learning question mostly. Only in rare case it need more money. But it may give money as rising name "good will" and better selling. 0.5k$ oscilloscope do not need be quality what can wait from 50k$ Rohde&S. But cheap things and even things without money can do and develop better. Owon have good base. They may win or they may loose. They make decision. They have promised to listen customers. It must not be empty words.
But also finally, I do not at all mean that Owon is some crap. It is amazing good in this price class. But this quality can rise better in some things and it can do easy. Only littlebit teaching/developing... and care working peoles better what give also better motivations... we are Owon workers, we need do perfect work - with every single unit... not only good average..
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Yes I saw your guide... thank you very much.
Owon sent me the "official" service repair guide, which is v1.0 (the same that is laying around in internet).
Maybe I'll give the scope some more hours of use to check if the fan noise goes away. On the other hand I'm considering using a Sunon mag-lev or another good quality fan if I have to change it.
Thanks again for your guide.
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"Firmware Version 2.5.1 Serial: SDS71021152xxx"
Please can you list what languages there is selectable?
If you do not regognize some language just list ???
I try still find what is difference in
Version 2.5.1 Serial: SDS71021152xxx
Version 2.4.1 Serial: SDS71021152xxx
(becouse they are same manufacturing lot but all 2.5.1 what I have heard are still outside of EU and I know big parcels are labeled in factory "EU")
So it is also possible there is different languages. Also in Owon specs, "Chinese, English, Others"
I don't know how to do the screenshot thing yet, so here's a picture of the languages:
(http://www.damado.com/electronics/scope1.jpg)
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Thank you DaMaGo!
Language set looks exactly same. So there is not different languages for localization.
Language menu looks exactly same. So there is not different languages for outside EU versions. It do not explain version difference.
This version difference is strange becouse manufactured same time. (1152)
Can you tell if last numbers in serial is less or more than 100?
Only what I have heard from "third part" is that "something" can wait later, maybe before end of January.
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rf-loop, the last 3 are over 100, almost 200.
It seems after the battery charged overnight, the unit doesn't get anywhere near as hot as it did. Last night, the BNC connector on the back was almost too hot to keep a finger on it. Now everything is room temp.
I think I might still exchange it just in case.
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Wasn't there some rumors that Owon was about to release a freely available firmware for the SDS line in mid/late December? Any news on this?
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Hi, guys!
I want to buy the SDS7102. But I understand that it can't operate with equivalent frequency (I didn't found it in user manual). Is it necessary option for periodical signals? How often is it used?
Thank you!
Of course there is some "theoretical" situations when it may be nice to have but only if it work well. I have not seen any cheap oscilloscope where it work well in this meaning what I mean.
Owon SDS serie do not have and do not really need this "Egual-Time" aka "Repetitive" sampling mode... becouse... this is not old tiny memory Tektronix. Also it is not 10MSa/s sampling 100MHz oscilloscope what really need this "Equ-time" sampling method.
Owon SDS7102 ADC can do 1GSa/s or 2x 500GSa/s.
It have 10 Megasample full speed acquisition memory for both channels.
It have real time sampling
Disadvantage with Equ-time" samplin is that it can use only with signals what are (exactly) continuous until whole sampling sequancy is done.
Yes if people have nice sinevawe example 100MHz and then have 10MSa/s ADC and good clock.. it can make image about this sinevawe. After waiting long time. If make 1. sampling turn, say example 1 sample to 100 ns time window and just to trig point (time reference zero) and keep this trig point. Then next 2. turn. Shift clock -1ns(related to trig point)... plot point to display... then 3. turn shift clock +1ns to trig point time and agen...4. -2ns, sample and plot point to display... etc (this is trig point prioritizing sequential repetitive sampling, there are lot of different methods, pure sequential, random, random littlebit weighted to sampling point etc ) then wait 100 turn. Well you have just 100 points after every 1ns and it is now 1GSa/s made by 10MSa/s ADC.
These was first developed becouse fast real time sampling was nearly or just impossible.
This also continues today becouse someone want 1GHz or 10GHz or 100GHz oscolloscopes what are possible only with some this kind of system until we have ADC or other method to measure signal and display it. Analog oscilloscopes can do it easy, up to 1GHz and even more. But making these today is so expensive that who can buy these with volumes. No one.
There can make special ADC hybrids what can do fast ADC today.
Also old times there was problems with full speed memory amount.
If we have oscilloscope where is small memory. As Tektronix say in "XYZs of Oscilloscopes": "Sample rate varies with time base settings – the slower the time base setting, the slower the sample rate."
Many older example 100MHz oscilloscope use 100MSa/s or even 10MSa/s. They really need this "Equal-Time" sampling.
And becouse "Old times" all good high-end name scopes have "repetitive" or "Equal-Time" super fast samplerate of course cheap oscilloscope manufacturers still use this for selling. Or some scopes still also need this becouse lack of real time enough sampling speed.
Owon do not need becouse it keeps its real time sampling rate also with slower horizontal speeds. 1GSa/s real time is possible all speeds from 500us/div to 2ns/div in single channel use and 500MSa/s to both channels simultaneously from 1ms/div to 2ns/div. This is just possible becouse Owon have 10M full speed acquisition memory for both channels.
It is perhaps some times nice if can do 10 - 50GSa/s "Equal-Time". If it have really enough accurate specially low timing jitter ADC and special good expensive timing "machine" in system it can do and sometimes it may be nice. (it need remember that 500MSa/s Nyquist is 250MHz! So if with 2 Channel use neer go over 100MHz frequency component it is nice to have some equal time sampling... but wait a minute, this IS 100MHz oscilloscope. So... where is problem. Imho, nowhere. But if try use it as 200 or 300MHz scope, it is not possible with two channels simultaneously. (analog front end is like 200MHz scope and in single channel use it is useful oscilloscope up to 200MHz frequency and more. Example 50MHz fast rising square vawes with 5th harmonic attenuated around ("only") 3-4dB and even 7th harmonic around -6dB. (think square vawe Fourier)
If accept 5th harmonic drop around 6dB it can well use for 60MHz square vawe. It can show well under <2ns risetimes in real time.
I do not know any cheap oscilloscope what have Equal-Time from 10GSa/s up to oh well heaven is limit... where is enough good timing and ADC for this. And, where it can use better if real time samplerate is enough?
Also it can think how accurate trigger it need.
1GSa/s real time means ADC databyte every 1ns. (databytes stream speed is 1Gbyte/s)
I want see acquisition system in cheap oscilloscope what is good enough for example doing continuous 50GSa/s equal time sampling. What it means. It mean 1GSa/s ADC have first sampled one turn... then sequentially or randomly time shifted so that after 50 turn we have sampled points after every 20ps yes after 20pico second. And so that this timing jitter is markable lower. Say example <5-10ps (or even <20ps) if want anything useful for these extra 49 sample points between original first turn samples with 1ns time interval.
Then also, if analog channel have frequency response for example 100MHz -3dB gaussian.
Now we sample real time 1GSa/s. What is this analog channel with 500MHz? (Nyquist-Shannon)
Now, what hell advantage it can give with 50GSa/s Equal-Time sampling. Just nearly exactly nothing but noise. Becouse bad sampling accuracy make it more bad, not more good!
This need also chinese EE's learn and peoples who read thousends of advertisement. Also do not take all arguments from Tektronix or Agilent (HP) old "teaching" and "teaching/ad" materials becouse they may made only compatible just exactly for they own unit or just for named competitor model. If look 1-2GSa/s cheap today entry level or littlebit better oscilloscope... just jump over this Equal-Time samplerate. Exept if you also want buy 100Mpixel camera with 2x3mm sensor and with cheap "camera obscura" lense.
I'm happy if someone can show to me any one cheap under 1k$ digital oscilloscilloscope what really can do it (real good Equal Time sampling with accuracy what 50GSa/s or 10GSa/s need) and really can show it on the screen so that there are every real sampled point plotted on the screen. (I like see this "shotgun hit pattern" and ask - what is now useful really?). I have not seen any good, never. Not even close this what give some value in this meaning.
But then... I have seen example 10MSa/s Hewlett-Packard what can do it (up to 10GSa/s equal time (or was it 5GSa??..) But still there is sampling jitter etc noise in these datapoints so that maybe really useful is around 1-2GSa/s egual time speed and other then these rest of dapatpoints do not give any more information.
Show me one cheap ADC system what can do this, show me any cheap clocking construction from cheap oscilloscope what can do it.. and then there is some processor/FPGA system also what do somthing for this timing. Well, in this meaning what is 50GSa/s Equal time sampling. It is just bullshit and big bullshit. Have anubody really seen on any oscilloscope screen these real equal time sampled points without any DSP recalculations and "cleaning" - "washing" for just nice picture. What is meaning for these equal time sampled points?
Nothing... just nothing. They are for selling. They are only that they can write to AD or even oscilloscope front end. It is very nice to show small hobbygirls that my oscilloscope front panel reads 50Gs/s just as I have seen this bullshit in one old Fluke. Just as plastic crap lense camera have 24Megapixel on the 4 millimeter CCD and my scanner have zilion pixel resolution (interpolation)) I understand if chingwangchangnippon write this to front panel but that Fluke. (It was Philips-Fluke)
I can well understand why 300MHz high end analog front end oscilloscope with 20 or 200MSa/s ADC system need "Equal-Time" or "Repetitive" sampling. It realli give something.. really. For repetitive signals of course.
But with cheap 100MHz analog front end together with noisy amplifiers etc... then insert 50GSa/s "equal time" sampling option and still oscilloscope have example 1GSa/s real time ADC.
It is maybe easy to undertand what foolishness it is. Of course it is not foolishness if this "feature" can sell to someone.
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Hi, guys!
I want to buy the SDS7102. But I understand that it can't operate with equivalent frequency (I didn't found it in user manual). Is it necessary option for periodical signals? How often is it used?
Thank you!
Of course there is some "theoretical" situations when it may be nice to have but only if it work well. I have not seen any cheap oscilloscope where it work well in this meaning what I mean.
Owon SDS serie do not have and do not really need this "Egual-Time" aka "Repetitive" sampling mode... becouse... this is not old tiny memory Tektronix. Also it is not 10MSa/s sampling 100MHz oscilloscope what really need this "Equ-time" sampling method.
................
Thank you very much!
I already ordered SDS7102 two days ago from eBay.
Now waiting...
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ehm rf-loop ... ADC quality/speed is nonsense for equivalent sampling (which is nothing else than sequential sampling on real time
scope/ADC system), "one bit ADC" sampling with 100MHz is good enough to measure Ghz signals - all you need is good timing
and analog bw higher than the actuall real-time ADC Nyquist bandwidth (the best frontend is no frontend like on real sampling scopes)
And exactly here is the major problem - analog bw costs money, you can only get it for free when manufacturer was
nice enough and designed universal frontend. Example Tonghui - frontend is switching from 60MHz to ~250MHz
when equivalent sampling or FFT will be enabled (on 60MHz model!!!) - and due only two ADCs the jitter is low
enough to use equivalent sampling. I tested it and it was the only chinese scope able to use that mode properly,
a big Thumbs up for that to Tonghui.
And the others? Well, useless .. not only because there is not enough analog bandwidth but especially because
some EEs simply don't know what equivalent sampling means. Instead of using one or max 2 ADC (to reduce
potential jitter becuase timing is everything in that mode!) they enabling all of them - and now think about the
jitter between 8 ADCs in Tekway/Hantek/Instek or even 10ADCs on Rigol/some UNI-T.
So for low bw models equivalent sampling can be implemented cheap, for the typical 1-2GS DSOs with 100-300MHz bw
the problem remains the frontend and timing accuracy.
Owon have good frontend and could on paper enable the 500-750MHz potential bw on even 60MHz models
when there would be equivalent sampling implemented ... and Owon is using one or max two ADCs ...
so yes - equivalent sampling could make sense/be implemented on these models.
Why Owon did not implemented it ? Probably because every chinese DSO manufacturer is thinking about
profit - and only profit. This is bilions $ market in china!
A working equivalent sampling is today still something special for chinese manufacturers, but not a reason for most
enduser to buy a gear because soem even don't know what this mode meand and others know that there are typical
sampling scopes available doing that job much better (see below).
Instead of that Owon just put 10Mpoint memory (with no markers, no dual window, cheap zoom ...) and
spend some money on announcements and "false" prospects (since months the website, user manual are
still not fixed, still mentioning 10Mpoints in all modes which is not truth as we know) and that's a good reason
to buy it for some users (where others are using dual windows, markers, complex zoom, O.T. triggers and holdoff to see the
same amount of information on "few kpoints" scopes)
I'm happy if someone can show to me any one cheap under 1k$ digital oscilloscilloscope what really can do it (real good Equal Time sampling with accuracy what 50GSa/s or 10GSa/s need) and really can show it on the screen so that there are every real sampled point plotted on the screen.
sure, http://www.fastsampling.com/ (http://www.fastsampling.com/) with 1ps accuracy.
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sure, http://www.fastsampling.com/ (http://www.fastsampling.com/) with 1ps accuracy.
There is programmable delay what resolution is 1ps. What it tell about whole system sequantila all timing errors or accuracy.
But, it is nice building box and this price... surprice and it can use as oscilloscope after there is also computer and for some special use with only repetitive signals just becouse real sequential delayed sampling method.
This 1ps is only programmable delay setting resolution and this is not 1ps accuracy.
Btw, 1ps is 1x10 Exp-12. (1THz cycle time) Light travel around 3.3ps one millimter.
;)
But then there come typical cheap oscilloscopes "Equal-Time" modes with 50GSa/s - yes and smile.
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Allah! ... of course not accuracy but resolution, the accuracy is between 10ps and 250ps only
(based on how good the guy implemented the TCM delay and few other things)
And yeah, the 25-50GSs are of course only (up)calculated, they can be real for sure but not with an cheapo frontend
and nanoseconds of jitter in clock.
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Example Tonghui - frontend is switching from 60MHz to ~250MHz
when equivalent sampling or FFT will be enabled (on 60MHz model!!!) - and due only two ADCs the jitter is low
enough to use equivalent sampling. I tested it and it was the only chinese scope able to use that mode properly,
a big Thumbs up for that to Tonghui.
Becouse I'm interest about all, also this Tonghui. (Tonghui is (maybe) one manufacturer in china what is also (with some equipments) in the professional markets in China)
What is this model?
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Becouse I'm interest about all, also this Tonghui. (Tonghui is (maybe) one manufacturer in china what is also (with some equipments) in the professional markets in China)
What is this model?
i tested TDO3062A which is already "older" model, the current Tonghui scopes have better or more ADCs and
sampling with 1GSs instead of 400Mss.
Overall quality was very good - PCB clean, shielding or trigger and channels, eough decoupling caps everywhere, clean supply
for ADCs, each voltage good filtered. No cheap components, good designed rontend->ADC couling (no relays but AD8182 to reduce
the cap. load allowing better bw).
Frontend was based on discrete FET and AD8330 (that's 150MHz VAG, 250 MHZ at -10dBm), trigger with AD8184/ADCM562BRQ,
ADCs like on Rigol/HanTekway - AD9288 - but only two o them in this 400MSs model, FPGA Cyclone III with DDR-RAM
and not SRAM "crap" (well SRAM is good too, but expensive and most scopes are sampling not with ull speed these SRAMS)
- and as in the specs really 2.4Mpoint, GUI with TI DSP ADSP-BF531 like on Rigol.
The jitter was almost zero, surprising good for low-end scope. Sure only 4 ADCs, but ttaht in principle
enought for other manufacturers using interleaved ADCs to make a bullshit :P
Actually there was nothing crap on that scope, except
- small 5.7" display (but for sure you can work with that too)
- firmware which was looking like on Rigol and not Tekway :)
- low sample rate on that model.
It could be interessting to see these new models (B and BS) with 1GSs and integrated frequency/function generator.
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Overall quality was very good - PCB clean, shielding or trigger and channels, eough decoupling caps everywhere, clean supply
for ADCs, each voltage good filtered. No cheap components, good designed rontend->ADC couling (no relays but AD8182 to reduce
the cap. load allowing better bw).
The jitter was almost zero, surprising good for low-end scope. Sure only 4 ADCs, but ttaht in principle
enought for other manufacturers using interleaved ADCs to make a bullshit :P
Actually there was nothing crap on that scope, except
- small 5.7" display (but for sure you can work with that too)
- firmware which was looking like on Rigol and not Tekway :)
- low sample rate on that model.
It could be interessting to see these new models (B and BS) with 1GSs and integrated frequency/function generator.
Thank you. Interesting.
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Not sure if battery performance has been posted before, but I got a little over 4.5 hours on just the battery while using 1 channel for about 80% of the time and the last 20% with 2 channels.
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Not sure if battery performance has been posted before, but I got a little over 4.5 hours on just the battery while using 1 channel for about 80% of the time and the last 20% with 2 channels.
It have been tested also here. (http://owon.forumup.com/viewtopic.php?p=7&mforum=owon#7)
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I'm sorry. There have been error in Guide. One pcture have dropped out. (picture 4. missing)
Here it is now corrected.
Illustrated Guide for Assembly and Disassembly Owon SDS improved version (http://www.box.com/s/pvg1dqtdonx192p4os0m)
Note for FAN:
Findings in service:
If you hear some abnormal noise just after start or shaking/turning oscilloscope to different orientation.
FAN maybe positioned just littlebit wrong in factory. It need be enough well centered to air hole in Z-plate. Other way there is possible that fan blade(s) hit this Z-plate edge becouse rotor can move some amount axial direction just enough.
Repair: Loose screws and ceter (it can move enough).
This may also damage fan sleeve bearing. Check. If bad bearing: fan need of course change.
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Hi
I've encountered another odd problem with my SDS7102 oscilloscope. When I was moving some of my stuff around I had it disconnected from the power gird over the night and when I powered it up again it wouldnt boot, and a red light instead of the green one was present. After a while in standby-mode the red light turns green, and when I turn it on the green turns red. When waiting even longer it'll boot up correctly but the settings are lost. (Measurements etc.)
Owon sent me a replacement power supply which I replaced today. Hopefully it'll fix the above problem.
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When waiting even longer it'll boot up correctly but the settings are lost. (Measurements etc.)
Owon sent me a replacement power supply which I replaced today. Hopefully it'll fix the above problem.
This settings lost is littlebit strange.
Normally it store settings last used after some time period. If change something and just shut off, it have not stored there. If wait some short time (seconds) it store settings in use and after startup it come bac to last state.
It loose also this?
There are also memory for save many different user settings what can later call from memory. It loose these?
How is time/date? Also loosed?
-----
Inside scope is one rechargeable very small capacity Lithium battery. Only just some mAh's.
But even after long time it dot normally loose memories. After just short power on time it have charged enough and normally keeping memory take very very small power. It feels littlebit strange this kind of power unit failure affect this memory loose.
But, after you change it you know more. You have seen this aghp guide new version about disassemble and assemble.
Owon own service manual (V1.0) is totally obsolete.
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Actually, I just saw aghps guide for disassembling. Although I figured it out myself. Wasnt really hard.
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So does the Owon SDS7102V brings the Lan adapter?
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Actually, I just saw aghps guide for disassembling. Although I figured it out myself. Wasnt really hard.
It is not hard. If people have some skill and some experience it is easy. We need remember there are many kind of peoples with different level of skills and experiences.
With wrong way it is easy also make some damages.
We have Owon service for our customers. Also in service, quality is one most important thing. We need do our works so that even if we handle new or nearly new units they need be just as before our work. Or better.
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So does the Owon SDS7102V brings the Lan adapter?
If it is older version, no. New versions have LAN as default.
V meand factory option VGA. This opition is not free. It can do only in factory.
LAN is today factory default and independent about VGA option.
Owon start this new HW production some time inside 4Q2011
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Did anyone make photos from the LAN chip? I'm thinking about upgrading my SDS8102 to a LAN version by myself. Therefore I need to know what chip is used. I would prefere photos of devices with LAN and the older Layout (as mine), but photos from the newer Layout could be helpful as well.
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Did anyone make photos from the LAN chip? I'm thinking about upgrading my SDS8102 to a LAN version by myself. Therefore I need to know what chip is used. I would prefere photos of devices with LAN and the older Layout (as mine), but photos from the newer Layout could be helpful as well.
New version 7102 LAN have this:
http://www.arrownac.com/services-tools/design-tools/arrowedge/parts/2009/vol2/pdfs/micrel_datasheet_ksz8851snl.pdf (http://www.arrownac.com/services-tools/design-tools/arrowedge/parts/2009/vol2/pdfs/micrel_datasheet_ksz8851snl.pdf)
I do not know new 8102 where is also LAN.
Old 7102 without LAN and new 7102 with LAN: Main board is new and different. It have lot of differencies but also of course lot of same. Layout have changed much. Also example VGA chip is now on the main board.
Btw: How about FW for old main board including added LAN?
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Btw: How about FW for old main board including added LAN?
the major problem with Owon DSOs is that they not using Linux, so you can't just "use a driver".
From the fw dump taken from the models without LAN i know that there is no driver inside, which means
ppl who wish to solder LAN chip need dump from newer DSOs.
On the other side when i look deeper into the firmware updates, there is nothing which looks like
a "driver" or "driver area" in flash and i really doubt that Owon would make a fw updater
which is NOT able to update all areas.
This means the "driver" is already implemented into the os file (which is the main app) and all
you guys need is just to solder missing parts.
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Here small picture
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nice, seems to match the old PCB pinout.
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Dont' know if this is the right thread, but I post this here since it
was briefly discussed before.
Handling 2x10Mpoints data dump from sds7102 is not easy.
So I thought to extract the data directly from .bin file and plot them
with a script.
For anyone familiar with python programming and for anyone
that wants to try I attach a small script.
It decodes the owon bin file, plots the waveform and
exports the data in a compressed matlab file format.
I'm starting with python, and this was a learning excercise,
anybody with some time and skills maybe can use it as
starting point for a better interface to load, show and analyze
the data.
The scripts uses python 2.7.2, numpy and scipy for
plotting and saving in matlab format.
The numpy and scipy package should contain many
functions for advanced data analysis, I've had no
time yet to study them.
If you have python numpy and scipy installed
just run owonreader_01.py
it should be self-explanatory.
Fabio.
P.S.
Thanks to aghp with his help in providing me
some key info.
Edit addendum:
if you download python, and install IDLE,
dont' run this app trough it, start it in a command
line terminal.
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My main hesitation when buying products like this from far away places is due to the service issues and time it can take to get any problems taken care of.
So I'm writing this as my experience in Owon's (and ebay's smtzone's) post purchase customer service.
As I mentioned on page 34 of this thread, my unit had a bad burning smell and self-shutoff right after doing the self cal and connecting it to the probe compensator thing. After that it seemed to work fine, but I wanted to exchange it since that just shouldn't happen and I was worried about future issues.
I had purchased it from smtzone on ebay and when I told them about the problem they were immediately willing to exchange it and always answered my emails within the hour.
Within one business day they gave me Owon's address and DHL account number to ship it back to Owon. I also had the option of smtzone sending me one from the USA immedately after giving them the tracking number, or getting the absolute latest from Owon directly but waiting for mine to get there before Owon shipped a new one. I liked this choice.
I chose to wait and get one directly from Owon.
I sent mine out to Owon from a UPS store (they ship DHL too) using Owon's own account # (so no cost to me) on Monday, January 9th and it arrived that Thursday my time (EST) which was Friday Fujian time (Friday Jan 13th).
Owon sent out a new replacement Monday the 16th and it arrived today, Thursday the 19th. That's damn fast for going to China from Miami, FL and back.
The model I had before was SDS71021152*** and the new one is SDS71021203*** (same 2.5.1)
I was very happy with the speed of service and excellent communication from both Owon and smtzone. So if you're worried about buying from China because of any red tape or delays, hopefully my experience can help you decide. I wouldn't hesitate to buy another Owon product from smtzone (aidetek).
Oh, my scope came with the battery but was told to ship it back without it. Owon sent the new scope with the battery cover instead of leaving it open (like when I shipped it back to them). It's nice having this cover for when I don't need the battery for whatever reason.
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This is just how it need work.
Owon have take big step to better customer care. Of course it is not ready - it can do better. I know they want continue to develop it better.
This is also how we do as Owon reseller here locally. Also this why we do not offer direct warranty time repair service to other country - due to high shippng prices inside Europe. From some EU countries it is more wise to use factory RMA procedure. All units are with full Owon factory warranty! If customer want we also help to solve these practical things between end user and Owon. What we do for reduce need of this RMA procedure? Before we accept unit for sell to end user, we make tests for every single units. For this we use around 3 day "burn in" (small pre ageing) phase and after then we check all is normal in this meaning what is normal Owon quality. If we find any problems we send units back to factory before selling. This can not of course eliminate random rare fails but it is much better than nothing. With this system risk for get "monday" unit.
Locally in our country we can do, with special price, even better than Owon itself in clear warranty fail cases. We can (in some situations) repair or change unit extremely fast. Some business customers want this extra service.
btw. One reason for this extremely fast case what DaMaDo tell is maybe also that in China just now start long holiday. There is Spring Festival. First many peoples want "table is clear" after new "year" start and also all know in China that next week all is closed. So if not keep hurry it go after Spring Festival and it takes long time before all systems are agen in normal state.
(small note: overseas warranty is valid only for units what Owon have manufactured and sold for overseas markets. There may be some chinese sellers who do not care this and then they "promise" full warranty even maybe so that Owon pay all. I have direct words from high chair in Owon that overseas full warranty is valid only for units what really have sold to overseas market originally from Owon.)
-aghp
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I apologize for a long time did not go to the forum :'(
This is nice information. Now know that also DS7102 1143xxx is "new" version? ( becouse LAN)
What is your version? V4.2.1 ?
Your seller have add "gift"? This one extra BNC cable. Not big value but something.
Abaut shows firmware version 2.3
And yes, the seller put in my free gift. BNC cable 1:1 with hooks. Not very applicable in practice, but it's nice.
I do not know, can I speak here, bought the DSO at seller eelab (http://stores.ebay.com/eelab?_trksid=p4340.l2563). Please do not assume advertising, but I received a very positive impression and 15% discount (sale action). In addition, I asked billed in Canadian dollars and receiv a savings of $ 10 to convert currencies.
You can e-mail Owon support to get the latest 2.4.1 version.
Thank you! I will write a request. Although the device works perfectly.
For all the time there was only one case of a locking firmware, which I was not able to reproduce later. I suspect that it was associated with a strong emission to the power supply unit.
The fan is quite acceptable. It is heard only late at night. In the daytime noise I can not hear it. I guess I was lucky ;)
Interestingly, when on battery power, my oscilloscope sees the first 2 channels of television and several FM radio stations. Admission is on a piece of wire long 5-7cm (2-3 inches). Sensitivity 5mV / div
Sensitivity 2mV is not suitable, because the limiter enabled to 20MHz band width
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A short review from my side after using my OWON SDS8102 for 2 Months. At first - I didn't get any firmware update for my device til know. I'm still using the 2.0 which came with the device. My dealer promised me that OWON will provide a download area on their hompage (for mid of december) but nothing happens. A little bit disappointing. I think I must contact my (official german) dealer again.
Another thing - I noticed a self discharge of my battery. After 1 or 2 weeks without using the battery was completely discharged, means dead. No reaction of the device. Do anyone have the same behaviour?
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Another thing - I noticed a self discharge of my battery. After 1 or 2 weeks without using the battery was completely discharged, means dead. No reaction of the device. Do anyone have the same behaviour?
Just checked my sds7102 after about 10 days of inactivity, battery indicator is half, I remember that last time was charged, but
i'm not sure 100%. Probably it will not be used in the near future, so I'll check next week.
aghp or rf-loop is it possible to measure battery voltage without dismantling the instrument?
Fabio.
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Another thing - I noticed a self discharge of my battery. After 1 or 2 weeks without using the battery was completely discharged, means dead. No reaction of the device. Do anyone have the same behaviour?
Just checked my sds7102 after about 10 days of inactivity, battery indicator is half, I remember that last time was charged, but
i'm not sure 100%. Probably it will not be used in the near future, so I'll check next week.
aghp or rf-loop is it possible to measure battery voltage without dismantling the instrument?
Fabio.
With power off, battery installed.
There is some power consumption.
Example it keep 2.5V reference powered and also some other small things.
Battery indicator do not show capacity left. It is, I tink so, very simple voltage indicator and this we know it is far away linear if think capacity.
So If battery indicator is just dropped around half, it do not mean that half capacity is discharged.
Personally I do not like that power unit is "active" if scope is shut off.
If battery is fully discharged, inside battery electronics shut off battery terminal so that it can only take current but can not give out. This is for disable deep discharge)
I have not measured battery discharge current when scope is shut off.
But example Vref (2.5V) looks like take something near 6mA. Alone this means 1.4Ah @ 10 day.
This and some other small consumption and also Li self discharge may explain some amount of what you have seen on battery indicator just also as it it not linear for Ah or Wh capacity)
This time I do not know what is total consumption!
But this need littlebit more study. I now have a hurry and therefore did not have the opportunity to do it well enough. I will try delegate this to some other person who is not so busy.
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Another thing - I noticed a self discharge of my battery. After 1 or 2 weeks without using the battery was completely discharged, means dead. No reaction of the device. Do anyone have the same behaviour?
Yes, mine does.
I hate devices which drain the battery when they are off. This always result in a dead battery when you need it most.
Is any workaround for this? Can a switch be installed that disconnect the battery completely?
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Another thing - I noticed a self discharge of my battery. After 1 or 2 weeks without using the battery was completely discharged, means dead. No reaction of the device. Do anyone have the same behaviour?
Yes, mine does.
I hate devices which drain the battery when they are off. This always result in a dead battery when you need it most.
Is any workaround for this? Can a switch be installed that disconnect the battery completely?
Not with these switches what are there now.
Of course if want modify it can do with separate switch.
I do not understand why they use these some circuits powered by battery in case scope is shut off or battery is not charged. There is no reason.
Maybe this design is from some other system what have need something and then it is modified for use in this scope without deep thinking. Who knows.
-
Hi there, some news about firmware updates. OWON did not make the firmware available on their homepage, but now they provided my official dealer with download links to serial number dependent patches. These links are at a share hoster! Curious. Unfortunately I only found patches for SDS6062 and SDS7102 but not for SDS8102, so I'm waiting again for the right link. The rar archives are about 100MB big, if someone is interrested...
edit: link deleted because of copyright :'(
The Firmwareversion is 2.7.1
-
But example Vref (2.5V) looks like take something near 6mA.
Small update for this.
It seems that current is totally around 7.5mA if battery is nearly discharged (measured). More if battery is full (becouse voltage is more).
Some kind of good estimate may be between 8-10mA.
battery nominal capacity is 8000mAh.
If it is 10mA it means around 800 hour. (littlebit over one month)
-
Hi there, some news about firmware updates. OWON did not make the firmware available on their homepage, but now they provided my official dealer with download links to serial number dependent patches. These links are at a share hoster! Curious. Unfortunately I only found patches for SDS6062 and SDS7102 but not for SDS8102, so I'm waiting again for the right link. The rar archives are about 100MB big, if someone is interrested..
I'd be very interested in the link for the 8102 as soon as you got one.
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battery nominal capacity is 8000mAh.
If it is 10mA it means around 800 hour. (littlebit over one month)
Thank you rf-loop for your info,
do you know also what happens when battery is low?
I suppose there is some low voltage protection in intrument and/or battery management circuit.
Does this trip at a "safe" voltage?
If not one should be adviced to remove the battery when the instrument is not used for long,
or recharge periodically.
Fabio.
P.S. All this to me seem bad design.
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battery nominal capacity is 8000mAh.
If it is 10mA it means around 800 hour. (littlebit over one month)
Thank you rf-loop for your info,
do you know also what happens when battery is low?
I suppose there is some low voltage protection in intrument and/or battery management circuit.
Does this trip at a "safe" voltage?
If not one should be adviced to remove the battery when the instrument is not used for long,
or recharge periodically.
Fabio.
P.S. All this to me seem bad design.
There may be some idea with this small current for keeping some control circuit alive. But first this current can be lot of less is designer really care about minimize this current. In design it need take care also that what ever time mains voltage can randomly vary what ever value between 0 - 240Vac (yes and it works also with DC mains ;) ) Not all have our standards with electric powerlines. These equipments sold also to area where is not any kind of good powergrid at all. Batt circuits control need always keep in order.
I do not know what is this battery self discharge. 10% ? 20% ? or what in month.
All batteries need human care. If people take some NiMh ... oh keep alone and after one month... nearly as empty.
-------
This Owon battery module have also build in low voltage shut off control circuit .
If battery is discharged there is control what disconnect output. (shut off output direction).
In this state it can not measure battery voltage at all. This locked state need first open. It can do with short charging phase. After short time charge it status is normal and it connect also current direction to out. After then it can agen discharge.
If leave nearly "locked" but still "output on" battery on the table for some weeks it self discharge and also then it shut off terminals BUT of course self discharging continue.
If battery is in "closed" state there is still some amount of electric inside cells.
It still continue slowly this self discharge and later also it go down to unsafe level.
So do not store empty battery very long time. Temperature speeds up this self discharge. If need store long time rkeep them in low temperature (if possible).
Lithium batteries need "human care". It is not just Owon, it is common to all Lithium batteries (rechargeable)
This selfdischarge speed depends battery technology (chemistry and construction), temperature etc.
I do not know what is this special battery selfdischarge.
It may be something like 5 - 20% per month... just quess.. ???
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I do not know what is this battery self discharge. 10% ? 20% ? or what in month.
If it's a at least decent I hope few % per month
All batteries need human care. If people take some NiMh ... oh keep alone and after one month... nearly as empty.
The difference is that a Zero-Volt NiMh recharges normally, a zero-volt Lithium is a dead one, also if it recharges back,
it's probably damaged. As a side note, apart the low discharge ones, I hated the NiMh because of the huge self discharge,
and worse the fact that cells from the same manufacturer and different lots had totally different self discharge rates.
If leave nearly "locked" but still "output on" battery on the table for some weeks it self discharge and also then it shut off terminals BUT of course self discharging continue.
If battery is in "closed" state there is still some amount of electric inside cells.
It still continue slowly this self discharge and later also it go down to unsafe level.
This is the reason I asked the voltage level and that for me there is bad design.
There is battery self discharge that should be equivalent to fraction of a mA or less,
than there is the safety circuit that should draw some uA. Bringing the battery
to very low levels in a month and after wait that the rest do the discharge job is dangerous,
and probably it should be not much difficult to make better, but we should see
the circuit to understand if it's an error or the price of low cost equipment.
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This is the reason I asked the voltage level and that for me there is bad design.
There is battery self discharge that should be equivalent to fraction of a mA or less,
than there is the safety circuit that should draw some uA. Bringing the battery
to very low levels in a month and after wait that the rest do the discharge job is dangerous,
and probably it should be not much difficult to make better, but we should see
the circuit to understand if it's an error or the price of low cost equipment.
Im now not sure did I explain something wrong with littlebit poor english.
"There is battery self discharge that should be equivalent to fraction of a mA or less,
than there is the safety circuit that should draw some uA."
This is inside Owon battery module.
Normal Lithium cell self discharge and very small safety circuit current draw.
Safety circuit control battery voltage on after reach low limit it shut off battery output.
When battery is installed in ocilloscope it is connected to Oscilloscope power supply. There in power supply circuit it keeps some control circuit also then alive and THIS is this extra draw current what discharge battery more than nessessary if designed really for this purpose. maybe there was thinked some safety things in some mains powerline situation but still this needes current is in my opinion much more than nessessary. 1mA - even 2mA I understand but 7 - 10mA is just from design where designer think "who cares" scope is on the table and connected mostly to mains. If not, battery go empty in one month but if this happend battery moule safety circuit stop deep discharging. And In china thee is not 1 month holidays.
Also it can design littlebit different and my opinonis that there do not need drav any current from battery if scope is off.
I littlebit think that this power unit is not originally designed at all to this SDS model. Maybe it is just quickly modified to use it in this model.
But who can keep normally his tool out from mains power more than week or two? And in this case then need full battery power withiut posibility to charge.
But this 7-10mA discharging always, it is still not nice and specially becouse there is not real reason.. not even remote control what need be stand by powered. (look this "magick eye window" under display)
-
Hi there, some news about firmware updates. OWON did not make the firmware available on their homepage, but now they provided my official dealer with download links to serial number dependent patches. These links are at a share hoster! Curious. Unfortunately I only found patches for SDS6062 and SDS7102 but not for SDS8102, so I'm waiting again for the right link. The rar archives are about 100MB big, if someone is interrested...
edit: link deleted because of copyright :'(
The Firmwareversion is 2.7.1
2.7.1 for what model?
-------------
This have been officially confirmed by Owon headquarters today (13.FEB.2012):
1. FW version 2.7.1 is for SDS6062
2. Latest official FW version for "new improved HW version" SDS7102V is 2.5.1
(There is not this FW level yet available for older SDS7102 models )
--------------
So, peoples, please. To avoid confusion, any reports on new FW versions, please tell also exactly what model you are talking.
- aghp
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Thats correct AGHP, and today I received my FW Update for the model SDS8102 from 28s week 2011 delivered with FW2.0 as Patch for my serial number. The new FW version which is displayed is 2.4.0
It brings the onscreen keyboard and a really working pulsewidth trigger. The copy button still does not work as expected. All in all not so bad I think.
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It now on the air.
Public FW update!
Here we go:
Go to THIS (http://www.owon.com.hk/index-en.asp) Owon side in HK.
Warning: There is bad bug in SDS7102 update to V 2.5.1!
(Default freezes scope and only way to out is power off. Also after this it do not set default)
Select Download
Select Software Upgrading
(Note: this time it seems that there is something wrong in downloadable or some other dowload integrity problem in this sds.rar file or there is something missing?)
Later I will upload it to other place for download more fast and reliable.
-aghp
BTW these Programmable Power Supplies and Arbitrary Function Generators are not yet ready - status is somethink like: "coming soon - we hope"
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This is somewhat crazy. My SDS8102 from week 28 of 2011 is excluded from this list. The download I just got from my dealer contains a MSO8202TD_OS_V3.0.5.1.bin dated 1/2011 and a (renamed) ZIP called bundles (-> the actual firmware archive) from 10th of February containing the following files:
tx
help
me
os
... all dated 10th of February...
The update went without issues, but the scope didn't reboot again just like after the 1st update I did last year (which however I was told is kinda normal).
The funny thing is, that although the help files were obviously updated this time, the scope now shows v1.1, while it showed 1.0 before (which also was wrong, as the firmware was already updated once before).
Then again, the file name dialog is there now, so this seems to be the newest version.
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This is somewhat crazy. My SDS8102 from week 28 of 2011 is excluded from this list. The download I just got from my dealer contains a MSO8202TD_OS_V3.0.5.1.bin dated 1/2011 and a (renamed) ZIP called bundles (-> the actual firmware archive) from 10th of February containing the following files:
tx
help
me
os
... all dated 10th of February...
The update went without issues, but the scope didn't reboot again just like after the 1st update I did last year (which however I was told is kinda normal).
The funny thing is, that although the help files were obviously updated this time, the scope now shows v1.1, while it showed 1.0 before (which also was wrong, as the firmware was already updated once before).
Then again, the file name dialog is there now, so this seems to be the newest version.
I think SDS8102 you have is old version HW. (..28..)
For SDS7102 I can see that all serials included in list are these new improved models.
Owon tell that update for these older SDS7102 units are not yet ready. Maybe it is also same for older SDS8xxx
I do not know this SDS8xxx becouse it is not here stock model.
-aghp
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Yeah, sure my model seems to be a little older. But it's just one week older compared to that of blueflash and still his displays 2.4.0 after the update while mine displays v1.1 although we probably got the same software. I understood that the 1st update last October or so didn't include the text file for the "about" dialog, but now the text files were updated and I still got a nonsense version number.
It's somehow not very reassuring that the same people who are supposed to fix bugs in the scope's software are unable to handle something as simple as a sensible HW/SW revision display. Not to speak of that crappy pseudo-security concept were they pretend that the SW is encrypted for the serial number, but it's just encrypted with some dummy private key and they deliver you the public key (in a file named "public.key") to decrypt the firmware on the PC before it's event sent to the scope.
If this is their security concept to protect themselves against cloners, then they should have asked someone with at least a basic understanding of encryption.
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This is somewhat crazy. My SDS8102 from week 28 of 2011 is excluded from this list. The download I just got from my dealer contains a MSO8202TD_OS_V3.0.5.1.bin dated 1/2011 and a (renamed) ZIP called bundles (-> the actual firmware archive) from 10th of February containing the following files:
tx
help
me
os
... all dated 10th of February...
The update went without issues, but the scope didn't reboot again just like after the 1st update I did last year (which however I was told is kinda normal).
The funny thing is, that although the help files were obviously updated this time, the scope now shows v1.1, while it showed 1.0 before (which also was wrong, as the firmware was already updated once before).
Then again, the file name dialog is there now, so this seems to be the newest version.
Sorry but I do not understand what model you are exactly talking and what model version numbers you are talking.
(becouse this MSO8xxx is also there. What is relation with this MSO thing together with SDS talking?
If you get SDS FW update from your dealer and then you tell there is MSO8xxx -- then in feel there is someting wrong.
I have seen SDS8102 and SDS8202 but I have never seen Vx.x version but all what I have seen is Vx.x.x
So, my recommendation is: take contact directly to Owon service and ask. Tell your SDS exactly model number and serial number and "about" diplay version, exactly, and ask what is ok FW version for your oscilloscope.
-aghp
-
Sorry but I do not understand what model you are exactly talking and what model version numbers you are talking.
(becouse this MSO8xxx is also there. What is relation with this MSO thing together with SDS talking?
Well, I clearly stated what scope I have. And how should I know why Owon provides me with patches that also contains MSO bin files? Probably because they lost the overview what has to be bundled in the patch.
If you get SDS FW update from your dealer and then you tell there is MSO8xxx -- then in feel there is someting wrong.
I got the first patch from Owon directly and it was the same, so it's a little unprofessional, but not a functional problem. As I said, the update was ok.
I have seen SDS8102 and SDS8202 but I have never seen Vx.x version but all what I have seen is Vx.x.x
Well, seeing is believing they say, and still my scope was delivered as v1.0, kept this fancy version number after the first update and now went up to v1.1 with a complete new update which includes new features (keypad) and bug fixes (e.g. FFT bug).
So, my recommendation is: take contact directly to Owon service and ask. Tell your SDS exactly model number and serial number and "about" diplay version, exactly, and ask what is ok FW version for your oscilloscope.
Apart from the fact that Owon service is not extremely responsive, they confirmed after the first update that the version number is not reliable and not (always) updated by the firmware update. Well, they don't really seem to care much about stuff like a sensible version system.
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It now on the air.
Public FW update!
Select Download
Select Software Upgrading
Later I will upload it to other place for download more fast and reliable.
Hello! I have tried to download FW update for my SD8202, but failed. I can see only links to blank page (and no links inside HTML, I have checked) on "software upgrading" page, and no links to the files. May be, files have been removed, may be something else.. Can you publish (preferred so anyone can use) or send to me fresh 8202 FW?
I have tried also register my DSO, but it displays alert with "thank you, you will get a gift" and display register form again. Strange, but it does not ask me for a email, so I have no idea what this site will do woth my name and serial number of my DSO. They cannot even write me a email, because they do not knows my email. :)
Thank you in advance!
p.s. As I can see, OWON can do the best of hardware, but definitely have problems with software, embedded or not. I sure (my opinion based on SDS8202 GUI), that FW was written not by a humans (because GUI is suitable only for species, that has big hand with L-type oriented fingers, and small micro-hand on it - for little encoder on upper right). :)
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Hello! I have tried to download FW update for my SD8202, but failed.
it seems they hav a plan :) look better now sure links (not yet) working but at least
splitted to models/versions.
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Hello! I have tried to download FW update for my SD8202, but failed.
it seems they hav a plan :) look better now sure links (not yet) working but at least
splitted to models/versions.
Can you download FW for SDS8202?
I cannot, theese links goes to nothing. When I try to download from http://www.owon.com.hk/down-en.asp (http://www.owon.com.hk/down-en.asp) - only links for downloading Windows software working. FW links open empty window.
May be OWON allows to download FW from some countries only?
-
no i can't and this is what i said - they updating their website right now!
Two days ago it was a single setup file (from a download size it does not matter really),
now there are prepared sections per model - which is good.
So just give them a day or two ...
-
AFAIK, FW update sharing is stopped due to problem (serious class unexpected bug) in least one model FW.
Owon examine and correct the problem and when it is finished it will be available. At the same time, they split the model-specific parts.
Patience. It needs that time what it takes.
-aghp
-
Note:
01.03.2012: Please do NOT use this link anymore. There is new update package available. Update version is still same. New include also update for older HW versions.
I will add soon updated package for new share. Just after I first check littlebit it.
If you want, it can now find Owon official webside but owon used download server is very slow and connection breaks frequently.
But I do not delete this downloadable so you can use it if you really want and can not wait day or two.
-----------------------------------------------------------
Original message:
Update (SDS7102 FW V2.5.1) is now available also here. (http://owon.forumup.com/viewtopic.php?t=48)
It is now repaired and "default" bug repaired.
Look carefully your serial number is listed! DO NOT try use for any other serials.
(we hopa later it is available also for older HW units (maybe with different version number??? but with Owon words: later)
(http://i969.photobucket.com/albums/ae171/Xie_07/OWONLILLIPUT.jpg)
-aghp
-
FW V2.5.1
Samplerate in "scan" mode is now lot of better.
Now it is same as normal and single shot mode. (as long as captured data is handled by oscilloscope itself. Scan mode save to USB or to PC is highly reduced.)
Here attached new samplerate vs memory table. Easy to see what means full speed 10M capture memory.
If someone find significant mistake in table, please tell it with email or PM. I want correct it.
-aghp
------------------------------
27.02.2011 Attachment deleted. It include error. New corrected picture later.
-aghp
-
when you find time measure the wfrm/s with 1k/10k (i assume 10M will be still the same)
and the latest firmware, could be interessting to see if Owon changed something.
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when you find time measure the wfrm/s with 1k/10k (i assume 10M will be still the same)
and the latest firmware, could be interessting to see if Owon changed something.
No markable difference from 1k to 10M memory.
Maximum is around 38 displayed visible separate captures on the TFT in one second.
(also trig out show same number)
(measured without accuracy, with one Fuji F200EXR 1 second shutter speed.)
This method proofs also that they really are separate drawed to TFT and visible)
Signal was 2,1MHz sinewave sweeped (slowly <1Hz) 6,3kHz deviation. Displayed position far away from trig position.
Shutter open 1s and then counted how many separate captures find in picture.
Later I use different signal generation so I can get better picture.
Also I will littlebit adjust enviroment so that better can use 1 or 2 second shutter speed.
Picture method is good becouse it do not forgive anything and it is not "imagination" with semi theoretical calculus. It is real seen on the TFT.
persistence, measurements and side menu off.
these all reduce this maximum number. Example persistence drops it nearly half.
So , some kind of maximum together with persistence is around 20 drawed displayed captures per second on the screen. Including full 10M.
Tested with one channel in use.
---------------------------------------------------------
Update, now get just one short quick tiny test.
Picture is terrible - horrible including also signal but only meaning is count how many captures displayed in second, thats all. With pocket camera shutter speed 1 second and also enviroment lights not best possible, then also ISO3200 ;) becouse want small f
Here littlebit different signal so that counting is more easy.
Whus just this signal and so on. Just becouse it was fastest find with equipments availabe for use so that no need disassemble some special other test systems - configurations (setting system back agen may be one day work, so... it want not do without really heavy reason).
Signal is continuously sweeping so that in picture left it first go littlebit left, then full trawel to right, then folded back more than half screen. (so it looks "random" timing.) This is becouse my slow ramp gen is other place.
Edit: This is perhaps not whole explanation. (Now, with new knowledge I think it was under 1s sweep period but... not so much faster. It is also possible there may occur faster trig and capture periods but they can not rise continuous capture rate and it stay around </= 38wfrm/s
Signal is sine. 1.5MHz. Level is so high that it go lot of over. So line is nearly vertical. This 1.5MHz sine deviate +-9kHz (no any reason) then adjusted trigger so much time offset that this deviation in rising edge of sine fills nearly whole screen (time axis).
Camera is set for 1s shutter speed. Horizontally picture is nearly whole screen, vertically cut becouse some backlights due to 1second shutter speed.
Trig out counting also show around 38Hz and there is around 38 waveforms visible on the TFT in this 1s time.
This around 38 is maximum for this scope with 1k to 10 Mega samples memory. .
Menu on, persistence on, mesurements on, they all affect reducing speed.
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Others same but signal and sweep different so that more easy picture. Only one direction moving signal rising edges (slow DC FM with HP3314B+HP8644B)
(total deviation was around 12kHz for 1.5MHz signal. Position in signal is far away (17us = 850div) from trigger point so that frequency deviation (rising edge position) is enough, around 10div total for easy take picture. (shutter time 1s)
Modulating signal (slow ramp) is not extremely pure, so also it may affect that freq sweep is not very accurate and it is visible so that these lines are not just exactly positioned, noise in FM DC mod level make here "time noise". Of course also some time errors come from trigger jitter and also other reasons.
It have done 38 full 10Mbyte capture in one second with used settings.
Horizontal speed is 20ns/div. 20 sample per div. Full one waveform (capture) lenght is 500000div.
One capture time is 10 000 000ns = 10ms.
Total time 1000ms
capture time 380ms
total blind time 620ms
of course if look visible part of signal this is terrible if compare to some fast realtime DPO like R&S etc.
visible to human eye is 15div, it is 300ns.
in one second 38pcs 300ns .. 11400ns.
Total time 1000ms
capture time visible to eye 0.0114ms.
blind time for human eye 999.9886
Blind/visible time ratios change dramatically if go to slower horizontal speeds becouse then more and more big part of whole memory is on the display. Example 10M memory and 500us/div it still use 1GSa/s but displayed is 15div from total 20div.
But also capturing speed drops to around 10.
20div 500us/div it means around 10ms capture time.
capture time 10ms, 100ms captured and there 75ms visible by eyes in 1000ms period.
But what happend in this case if drop memory.
1M and 50us/div. And capture lenght 20div and visible 15div. 1GSa/s used.
Now capture speed is 30.
Capture time 1ms, 30ms captured and there is 22ms visible by eyes in 1000ms period.
Here I did not try find any optimal visible time ratio or total blind time ratio.
It need some lot of tests if try find what is optimum memory, speed etc for signal what is looking and what try find.
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Hello!
I have SDS8202 version w/o VGA, and as I can see, I need to solder only U9 and VGA connector, all others chips are soldered.
So can anybody post here pictures of PCB around VGA area, from both sides, any SDS scope with new HW?
What is U9 (near VGA connector)?
What is U63 (big chup between cross-pcb IDC connector and lithium battery)?
Thanks in advance!
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Here new corrected samplerate table:
Sorry about mistake. SDS7102 do not have 1ns/div. Table was made using SDS8xxx table.
Agen, if someone find some serious mistake, please inform PM or email.
(http://i181.photobucket.com/albums/x2/aghp55/SDS7102_Samplerate_V251.jpg)
.
(http://i969.photobucket.com/albums/ae171/Xie_07/OWONLILLIPUT.jpg)
-aghp
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Hi, I have just bought SDS7102 with serial number SDS71021149xxx. I checked it like describe rf-loop. I did default, and I had wait 30min. After that I did self calibration and I turned it off and on.
Image1: 50 ohm terminators have been applied to CH1 and CH2, acquire have been set to peak detection mode, memory 10k, time base 10ms/div, CH1 and CH2 x1, 2mVac,
Image2: 50 ohm terminators have been applied to CH1 and CH2, acquire have been set to sample mode with persistence set to 2s, memory 10k, time base 10us/div, CH1 and CH2 x1, 2mVac,
From Image1 and 2 we can see clearly that my unit have problems.... but when I left BNC sockets open (without terminators .. see Image3) the both channels were the same?? Terminator should eliminate external noises, isn’t it? But when i put them, the CH2 left without changes but CH1 started to show waveforms like Image 1. Can anybody explain my why is that? I’m going to send it back to service and I’m pretty sure that they will checked it without using terminators.
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Hello all. I have a question for anyone else who has an Owon SDS 7102. In XY display mode does inverting the channels have any effect. It didn't for me and I was wondering if I am missing something simple...
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Hi, I have just bought SDS7102 with serial number SDS71021149xxx. I checked it like describe rf-loop.
From Image1 and 2 we can see clearly that my unit have problems.... but when I left BNC sockets open (without terminators .. see Image3) the both channels were the same??
I’m going to send it back to service and I’m pretty sure that they will checked it without using terminators.
This problem is fully examined and solved before. Your unit have exactly this "CH1 noise problem". Your case, the problem is quite clear. There is no doubt.
This problem was in early phase after Owon made this new improved version. There is mistake in construction.
Sometimes it do more, sometimes less level this problem.
If your Owon service do not regognize this problem they are not Owon service at all.
Every Owon service know exatly this problem and they can easy repair it. Also you have seen this small "manual" for this repair what I have made.
If you send it to Owon itself, please write note. "This unit have CH1 noise problem"
If you send it back to some other write more this: "This problem is well known in Owon, please contact Owon service engineer if you do not regognize this problem".
Illustrated guide for repair is here: http://www.box.com/s/pvg1dqtdonx192p4os0m (http://www.box.com/s/pvg1dqtdonx192p4os0m)
http://owon.forumup.com/ (http://owon.forumup.com/)
If you have new Owon SDS7102 with LAN and it have serial
SDS71021143xxx - SDS71021151xxx
(exept if you have purchased it from me = sure it do not have this issue!
-- all units I sell have been in full tests and QC in my lab)
Please check if CH1 have special noise problem.
(you can find english explanation example in EEVBlog forum)
Inside Finland, locally, I can also repair it as Owon service.
Becouse I have not sell it The price of labor is a small nominal charge.
If you want do it your self and you understand that warranty may void after your own work I can give simple instructions how to do it. It is fully mechanical work and no need solder anything.
These two last sentence are for people who can not use or not want use Owon warranty if there is some individual personal reasons. But remember, after self repair you are responsible. Example ESD may damage so that after repair unit work normally but after some weeks or even after months it suddenly fails.
But first:
1. Ask your seller what to do. (and explain that this problem is well known inside Owon factory)
--if they promise themself repair it it is ok, if they only "change" unit it is not ok becouse all units inside this serial number area may have or have this problem more or less.
2. Ask Owon directly.
-aghp
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Ok., thanks:) I have already written to Owon and to my seller. I hope they will send it to professional service, If not I will simply return it and look for new seller.
Once again thanks. Btw are You selling Owon scopes in Europe or only locally?
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Ok., thanks:) I have already written to Owon and to my seller. I hope they will send it to professional service, If not I will simply return it and look for new seller.
Once again thanks. Btw are You selling Owon scopes in Europe or only locally?
In Europe, EU area.
In EEVblog you find this information here. (https://www.eevblog.com/forum/buysellwanted/fs-owon-sds7102v-(lan)-(eu-excluding-finland)/)
--------
note:
There may be some unexpected delays now in Owon service becouse they are arranging some customer services and they have lot of problems with some chinese email services.
They are changing some things to HongKong but seems it do not yet work well.
Also Owon official internet side have changed: OWON official side is now:
http://www.owon.com.hk/ (http://www.owon.com.hk/)
It have officially changed around week ago.
-aghp
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Looks like Owon released new version of update software, now supporting older HW revisions of SDS7102 with the latest 2.5.1 fw.
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:) Good one Owon 8)
Owon seem to get some bad press on here from the Rigol Mafia.
True the early Owon versions had some real bugs but I think that early Rigol models and the ongoing issues with the Hantek go to prove that they are what they are...lower end equipment and thus you must be prepared for some bugs and performance short cuts.
What I do like about Owon is that they seem committed to getting there customer support right. They have consistently updated the FW and even improved the HW on the latest models. They seem to me, to be trying their hardest out of all the Asian brands to get it right, which is refreshing.
I think the Youtube review of the early SDS7012 by a well known member on here hasn't helped Owons cause, I just wish he would use his obvious in depth knowledge of scopes, to review the updated version which I must admit I love and own. ;)
If you are in the market for a low-mid end DSO then from my experience the Owon SDS models should be in your short list.
There is a EEV member on here (aghp) who deals with Owon in Europe and would be more than willing to help with any questions you have about the Owon kit.
p.s. I am not affiliated with Owon in any way bar that I am a happy Owon SDS7012 owner. :P
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Becouse Owon hk download is some times extremely slow and also it may break connection unexpectedly here is other source.
Downloadable zip include: OWON_Patch_1.8.0_Setup_V2.0 + Md5 check tool + Readme.txt
zip is around 81Mb (directly from Owon it do not have Md5 check)
Here you find link to downloadable. (also of course it can find Owon HongKong side but sometimes it is very slow)
Update (SDS7102 FW V2.5.1.x) is now available. (http://owon.forumup.com/viewtopic.php?t=57&mforum=owon)
It is for older and new versions.
Look carefully your serial number.
I have tested with couple of units and after update these what I have tested:
V 2.5.1.6
(dependent your model/version there may be 1 or 2 number after 2.5.1 (2.5.1.?.?)
(http://i969.photobucket.com/albums/ae171/Xie_07/OWONLILLIPUT.jpg)
New Download 2.5.1.x (http://www.mediafire.com/file/jpa6jj9vparqu8a/SDS7102_FW251_V2.zip)
-aghp
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Can enybody tell me how the vertical position adjustment is implemented? Is it adjusts voltage bias on analog frontend before ADC input, or it just moves a signal trace?
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Can enybody tell me how the vertical position adjustment is implemented? Is it adjusts voltage bias on analog frontend before ADC input, or it just moves a signal trace?
It is adjusted in analog front end before ADC
Input (analog front end) principle is conventional and quite well designed.
Vertical shift is not designed in kindergarten just as digitized trace shift.
First there is some passive components (step attenuator) R,C,(L) + Fujitsu RF relays and AQY214 as AC/DC switch
then:
1. ADA4817 Low noise fast 1GHz FET amplifier
2. ADA4932 >500MHz differential driver Input offset adj come here from AD706 to ADA4932 Also of course ADC Reference V is here.
3. LMH6518 Digitally controlled 900MHz variable gain amplifier. Primary differential out to ADC and auxiliary differential out to Triger mux
4. MXT2002 2x500M/1x1000M ADC (ADC08D500 clone)
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rf-loop, thank you for dispelling my doubts.
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Not very bad.
Measured with peak-peak using 1M memory and 1GSa samplerate with 50us/div.
Persistence infinite. Then stop. Zoom out so whole capture is on the screen. Then with cursors.
(with this setting Owon capture is 20div lenght so whole capturing is easy to look after one step zoom out and so that it is littlebit comparable to Agilent paper. (not exactly but no big difference in this noise meaning. Of course other kind of setting give lot of better result but this is not AD, so...nearly worst case realism. But this I do not know how much Agilent paper have bias... )
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rf-loop: very impressed that you put together all those noise floors for sample scopes. I've seen some of those data from the Agilent application guide so I confirm your data.
http://cp.literature.agilent.com/litweb/pdf/5989-3020EN.pdf (http://cp.literature.agilent.com/litweb/pdf/5989-3020EN.pdf)
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But this I do not know how much Agilent paper have bias... )
That's an important point. They won't flat-out lie, but they will optimize the settings/circumstances that make the competition look bad and them look good.
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I've just looked at power supply board circuit and have noticed that there is no battery management section except a "fake" battery charging indicator which just turns the LED off when a voltage becomes higher than some constant value.
So it seems that a battery module itself has a charging circuit in addition to a standard protection module.
Has anybody disassembled a battery and know how it is implemented (can it be disassembled without damage at all)? I've ordered a scope with a battery, but it will be delivered to me at the end of this month, so it is too long to wait...
$60 seems to be a very nice price for 4x4000mAh Li-Pol elements with a charger and a balancing circuit, so wondering about using it as a plug-in module for other devices.
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Absolutely true, but that holds for all application notes coming from manufacturers, it is geared subtly to make their products shine over their competitors, such as Tek's own scope notes.
However, its easy to confirm those readings; any owner can measure their quiescent noise themselves; but getting a chart with all the data together is more elusive. It also serves as a simple yardstick to determine if your DSO noise is a bit more than should be.
I just checked this morning and as expected because of the lower bandwidth, an unmodded 50 MHz Rigol has under half the noise of all V/div ranges, using p-p values, using Agilent's method of shorting the output channel with a 50 ohm terminator.
But this I do not know how much Agilent paper have bias... )
That's an important point. They won't flat-out lie, but they will optimize the settings/circumstances that make the competition look bad and them look good.
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explain how to measure noise at rest?
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explain how to measure noise at rest?
In comparation table there read Agilent 5989-3020EN
After then "saturation" have give this link:
http://cp.literature.agilent.com/litweb/pdf/5989-3020EN.pdf (http://cp.literature.agilent.com/litweb/pdf/5989-3020EN.pdf)
Do it need now copypaste here what reads in this Agilent paper?
I can help: It is explained on the side 4.
But it is better to read whole paper first and try understand what there reads. Then agen side 4.
Idea is collect enough data and find there peak level.
If example set Owon to 1k memory, 50ns/div (1GSa/s) and look what see in display with different V/div settings it looks lot of better. (example around 1.4 - 1.6mV p-p looking when scope is running but if collect more data with 1M or 10M setting and then look whole data there is peaks 2.4mV.
Measurement can do with open input and / or with terminated input. If open input enviroment need be EMI free so that input do not collect outside noise.
Visually with scope running it looks even better becouse eye do small trick with fast noise peaks. (in analog oscilloscope phosphor do this "noise filtering")
So, stop scope and then take whole collected data to screen so that it is example inside 5 - 10 horizontal divs. Then it can clearly see how fat is trace.
Also it can analyze from stored data file.
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Hi guys,
I am very interested in this Owon SDS7102, because my analogic scope seems to have some problems recently...
I searched where to buy this Owon and, except buying from China on ebay at ~380€ (with battery), it seems that I can't find it anywhere else with its battery for less than 500€, which becomes quite expensive...
But buying from China does not make me very confident about warranty, shocks during transport,... And what about any duty (because it comes from China) ? Sorry my English if I don't express myself clearly.
Another problem when buying from China is that I don't know if it is the latest version of the scope, I heard that some bugs have been fixed recently.
So it would be great from you to answer my wonderings about buying from China. And if not, where (in the EU) could I buy this scope with its battery for less than 500€, latest version ?
Thanks a lot for your help,
Ryl
PS : I still wonder which one is the best between this Owon and the Rigol 1052E (which isn't expensive at all)... But I heard about the fan noise (I hate that) and I don't want to take the Rigol apart to change it.
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So it would be great from you to answer my wonderings about buying from China. And if not, where (in the EU) could I buy this scope with its battery for less than 500€, latest version ?
I think nowhere Ryl, if I may ask where are you from?
There is a little online store in the Netherlands, price without battery is 449 Euros + 75 Euros for the battery:
http://www.eleshop.nl/nieuwe-serie-owon-sds7102-p-480.html (http://www.eleshop.nl/nieuwe-serie-owon-sds7102-p-480.html)
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Don't forget about VAT and import duties. A large, high-value item is more likely to be picked up by customs than a small padded envelope. Expect ~€70 VAT + €0-€38 duty (don't know the tariff for DSOs by heart) + whatever the transport company wants to charge for taking your money (eg. brokerage fee).
aghp (https://www.eevblog.com/forum/buysellwanted/fs-owon-sds7102v-(lan)-(eu-excluding-finland)/15/) on this forum appears to offer reasonable prices (cheaper than the above 'eleshop.nl' price) and good support. You won't find many other vendors offering burn-in testing for free.
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Thanks for the tips, I'll look at those sellers.
When looking at ebay sellers, I forgot the duties il my calculations... That makes a difference.
Ryl
PS : I just updated my profile, I live in Belgium. :)
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DSOs made in China are duty free in EU - the base TARIC code is 9030 20:
http://ec.europa.eu/taxation_customs/dds2/taric/measures.jsp?Lang=en&SimDate=20120311&Area=CN&Taric=9030&LangDescr=en (http://ec.europa.eu/taxation_customs/dds2/taric/measures.jsp?Lang=en&SimDate=20120311&Area=CN&Taric=9030&LangDescr=en)
Edit: Of course, you would have to pay VAT on price + shipping.
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Alm, he is from Belgium and eleshop is even closer to him than me while I am in the Netherlands :)
There is no big price difference if you ask me, I would rather go for a shop which is closer to me than one further away, the option with battery is only 13 Euro more and without battery same.
That’s nice to know marmad, but is that for company’s? Because on some Dutch forums people got caught with an oscilloscope and had to pay VAT.
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I'm talking about personal import - not commercial. There are two different 'taxes' we are talking about: duty (douanerechten in Nederlands) and VAT (omzetbelasting). In principle, when you import from a non-EU-country, the following rules apply (based on the value):
0 to € 22 = No duty / No VAT
€ 22 tot € 150 = No duty / Yes VAT
€ 150 and above = Yes duty / Yes VAT
If the customs people don't look at your package at all - then, of course, you might not have to pay anything. But if you must pay duty, the amount that you must pay is based on the TARIC code and tariff (which you can look up at the site which I linked in my previous post). In this case, a DSO made in China has a 0% duty - so no extra import fee even though the value is more than € 150 - but you still ALWAYS have to pay VAT if the value is listed as more than € 22 (and/or customs check the package).
Edit: Also, the values listed above (and the amount on which VAT is applied) is the cost PLUS shipping - in order to avoid people getting around duty/VAT by claiming the value is € 1 - but the shipping cost is € 100.
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Thanks marmad :) nice explanation, yeah the VAT (BTW in Dutch) is 19 to 21% over here, I am not sure which applies to an oscilloscope.
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4. MXT2002 2x500M/1x1000M ADC (ADC08D500 clone)
Is there any documentation available? I've found only two links, both on Chinese and both have quite a bit useful information:
http://www.mxtronics.com/NewsInfo.aspx?titleID=301 (http://www.mxtronics.com/NewsInfo.aspx?titleID=301)
http://www.spacechina.com/n25/n144/n206/n216/c190964/content.html (http://www.spacechina.com/n25/n144/n206/n216/c190964/content.html)
Also on the photo you posted here (https://www.eevblog.com/forum/product-reviews-photos-and-discussion/review-of-owon-sds7102/msg63845/#msg63845) it seems that the ADC package is brown. Is it just a uncommon compound color or something else?
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4. MXT2002 2x500M/1x1000M ADC (ADC08D500 clone)
Is there any documentation available? I've found only two links, both on Chinese and both have quite a bit useful information:
http://www.mxtronics.com/NewsInfo.aspx?titleID=301 (http://www.mxtronics.com/NewsInfo.aspx?titleID=301)
http://www.spacechina.com/n25/n144/n206/n216/c190964/content.html (http://www.spacechina.com/n25/n144/n206/n216/c190964/content.html)
Also on the photo you posted here (https://www.eevblog.com/forum/product-reviews-photos-and-discussion/review-of-owon-sds7102/msg63845/#msg63845) it seems that the ADC package is brown. Is it just a uncommon compound color or something else?
Here you can find RuiFeng (http://aoxunf127.w290.bizcn.com/e_Products2.asp?ClassId=57)
tiny datasheet pdf here (http://www.mediafire.com/file/b5czrf664qm7cz4/MXT2002.pdf)
Functionally it is afaik same as common known ADC08D500.
Some specs just littlebit better in original but...
Price difference may be ... just more than big.
Package is nearly same. (not exactly direct pin-pin becouse RuiFeng have added some N.C. pins to corners.
Color: Chip is black.
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Guys ... The SDS7102 is also ADS1102 .... Uni-T DSO4202B, Hantek DSO5202B, Le Croy WaveAce212, B&K 2542, Tektronix TDS1012B
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Guys ... The SDS7102 is also ADS1102 .... Uni-T DSO4202B, Hantek DSO5202B, Le Croy WaveAce212, B&K 2542, Tektronix TDS1012B
Hi Dave - the SDS7102 is NOT equal to the ADS1102 and the other above??
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Guys ... The SDS7102 is also ADS1102 .... Uni-T DSO4202B, Hantek DSO5202B, Le Croy WaveAce212, B&K 2542, Tektronix TDS1012B
Hi Dave - the SDS7102 is NOT equal to the ADS1102 and the other above??
Same screen size . ADS1102CAL .
http://www.epinions.com/content_578790395524?sb=1 (http://www.epinions.com/content_578790395524?sb=1)
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Same screen size . ADS1102CAL .
Seriously? You pop into a thread 41 pages long to let us - the people here using and discussing the (relatively) new SDS7102 - that it's the same scope produced by many others?
No offense, Dave, but you don't know what you're talking about. Firstly, the Owon SDS7102 screen size is 8" (800x600) - by far the largest in any sub $500 scope - and not at ALL the same screen as the ADS1102. Secondly.... geez.... just read the thread already.
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Also, Dave, just to clarify further before Tinhead jumps in and tears into you... although both the ADS1102CAL and the Hantek DSO5202B both have a 7" screen, the Atten scope's resolution is 480x234 pixels, while the Hantek's is 800x480 - a WORLD of difference. So even the other scopes (aside from the Owon) which you mentioned as equivalents are NOT equivalent.
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I would second marmad on his comments. Appreciate your enthusiasm Dave.S but your comments are premature. A comment by another user at the link you posted already wrote of serious issues with the Atten that the reviewer cannot confirm as he has never tested his Atten beyond 200 kHz. What he has confirmed already suggests subtle distortions with the FFT implementation.
http://www.epinions.com/content_578790395524/show_~allcom?sb=1 (http://www.epinions.com/content_578790395524/show_~allcom?sb=1)
Also, Dave, just to clarify further before Tinhead jumps in and tears into you... although both the ADS1102CAL and the Hantek DSO5202B both have a 7" screen, the Atten scope's resolution is 480x234 pixels, while the Hantek's is 800x480 - a WORLD of difference. So even the other scopes (aside from the Owon) which you mentioned as equivalents are NOT equivalent.
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Saturation - I envy your ability to ascribe the positive motive of enthusiasm :) ... and I do mean that sincerely.
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What a coincidence, damn, another bump into his crap post again here, seems like he dumps his crap almost everywhere in this forum. >:(
Just check this out HERE (https://www.eevblog.com/forum/projects-designs-and-technical-stuff/running-a-laptop-off-eneloop-aa's/msg97273/#msg97273) or HERE too (https://www.eevblog.com/forum/general-chat/tektronix-2200-series-fan-noise/msg97690/#msg97690), its just unbelievable. :(
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What a coincidence, damn, another bump into his crap post again here, seems like he dumps his crap almost everywhere in this forum.
I did notice that Dave S. joined the forum just a month and a half ago - and has been posting at a frequency of over 9 posts per day since. But, as saturation pointed out, enthusiasm is a good thing to have (especially here).
But Dave, you should perhaps scan the thread a bit before posting information that is obviously wrong. For example, it doesn't take much research to see that the SDS7102 is nothing like the Atten ADS1102CAL - different screen; different ADC configuration; etc. I don't know if you own an Atten (I think you do) - so please don't take offense - but the SDS7102 is a much superior scope (although, granted, costing more money).
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It's according to that guy :)
And yes i know the Owon has 800x480 reso , i'm just directly quoting HIM .
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Guys ... The SDS7102 is also ADS1102 .... Uni-T DSO4202B, Hantek DSO5202B, Le Croy WaveAce212, B&K 2542, Tektronix TDS1012B
Dave.S:
Maybe you have find this "information" somewhere internet?
Do you believe all what you can read in internet without any criticism?
Maybe you have read this stupid lie. Someone keep trutht away from his upstair.
Perhaps you find it here (1) : http://www.epinions.com/content_578790395524?sb=1 (http://www.epinions.com/content_578790395524?sb=1)
or some other source becouse spread on the Internet as a pandemic just becouse peoples (just as example you) . spread without the source criticism and maybe even so that did not even know what they are talking about.
Quoted from (1):
Atten appears to also make this DSO branded as the Owon 7102T, the Uni-T DSO4202B, the Hantek DSO5202B, the Le Croy WaveAce212, and the B&K 2542.
It seems that Atten have selected this way for AD? If so, very pity. Maybe it is better first learn how to self design oscilloscopes and not only copycat others. I have wait Atten first self designed model but... maybe I need continue waiting - forever.
This - "The SDS7102 is also ADS1102" - is exactly big lie. Where is truth, why spread it here? Dave.S: Why?
Also what you do, you add more lie to original lie. There read: Owon 7102T. <<--- WHAT hell is this? Only Owon 7102T is PDS7102T what have nothing to do with SmartDS series SDS7102 !
Atten have nothing to do with Owon. If some Atten people walk to inside Owon factory maybe security peoples kick her out faster than he finds it.
Aktakom some models are well known rebranded Owon!
Also other companies can rebrand Owon. There is all ready possible order own front panel labels and there is free place for OEM data in memory, (example for start up screen)
-aghp
ps. Kind note to Dave.S: If you really want spread lies and disinformation, please open your own thread for these purposes. Do not pollute serious informative threads.
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I was directly quoting him
out of humour .
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Just don't take him too seriously, he is a clown, check this out -> HERE (https://www.eevblog.com/forum/general-chat/tektronix-2200-series-fan-noise/msg97866/#msg97866) and read his responses there as well, just can't believe it.
About spreading blatant lies, if he keeps doing this, this should be enough warrant to get booted from this forum, worst than spammer. >:(
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I was directly quoting him
out of humour .
If that was true then you went about it the wrong way; it's impossible to infer intent in text without more evidence. If you had written it this way:
Guys ... The SDS7102 is also ADS1102 .... Uni-T DSO4202B, Hantek DSO5202B, Le Croy WaveAce212, B&K 2542, Tektronix TDS1012B ;) http://www.epinions.com/content_578790395524?sb=1 (http://www.epinions.com/content_578790395524?sb=1)
...then it would have been understood as humor.
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It's according to that guy :)
i'm just directly quoting HIM .
stop quoting start thinking (or actually use search function in this forum and compare by yourself just the pictures of mainboard).
The problem with quoting reviews like this http://www.epinions.com/content_578790395524?sb=1 (http://www.epinions.com/content_578790395524?sb=1)
is that they made by an idiot* and not usefull at all.
Why idiot? Well only idiot will compare front panel pictures
http://home-and-garden.webshots.com/album/581243391pwaPvH?vhost=home-and-garden (http://home-and-garden.webshots.com/album/581243391pwaPvH?vhost=home-and-garden)
and come to conclusion they equal. You can accept such statement from anybody but not
from "electrical engineer" (which he is as stated in job description).
* - sorry but i have to call such ppl by name, that's the only way to stop them from posting bullshit
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Hi tinhead :)
You can accept such statement from anybody but not from "electrical engineer" (which he is as stated in job description).
Yes, very odd indeed. It seems strange that he's not aware of eevblog and all the discussion here of Atten, Owon, Hantek, clones, etc, etc.
@Dave S.
If your intentions here (and in other threads) are just to inject some humor and/or fun, you have to be a bit careful - or you will become known as a troll, which is generally undesirable - unless that's what you want.
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(http://i40.tinypic.com/168vnf4.jpg)
Indeed . Didn't read the T . Subtle i guess , my fault . :)
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To any users (or sellers) of the SDS7102 with the newest firmware:
I notice that Owon has been fixing some of their bugs in their updated firmwares, but I wonder if they have also been adding/fixing new/missing features as well. Could someone please let me know if any of the following 'features', which I listed earlier in my review (in ascending order of importance), have perhaps been added?
1) Show all measurements at once.
2) Linear interpolation of points or just the ability to turn off sin(x)/x.
3) Equivalent time sampling.
4) A SCPI command set or just improved data-exporting ability.
5) Coarse/fine adjust of volts/div.
6) Split-screen window for FFT or zoom.
7) A way to mark, search easily, or just jump through long wave records.
Thanks for any help.
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marmad,
I just ordered a 7102 from Saelig which should be here mid next week. I asked them to make sure I get the latest S/N unit they have--they said all their stock was the latest.
I'll check your feature list when I get it.
Thanks by the way for all your review work. Awesome.
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Sorry If I've missed it , but the buttons to the right of the LCD.. is it possible to press these without bracing the unit? It seems like being membrane switches you have to hold the unit with the back of your hand in your vids to stop it moving or falling over. Could be annoying
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Sorry If I've missed it , but the buttons to the right of the LCD.. is it possible to press these without bracing the unit? It seems like being membrane switches you have to hold the unit with the back of your hand in your vids to stop it moving or falling over. Could be annoying
Yes, it's possible, but only just. I like to hold the top of the unit with my hand and press the buttons with my thumb.
@marmad: thanks for your great review. It pushed me to buy the SDS7102 and I'm happy so far. I'm still learning how to use the DSO so I'm probably not the right one to answer your questions, but by looking around in the menus I'll try:
1. There is a button in the Measure menu labeled 'Show All'. It shows all applicable measurements at the time of the button press (ie. it doesn't update while the window is displayed)
2 - 4. I'll leave these questions to someone with more oscilloscope experience. I couldn't find any settings related to this in the menu.
5. Coarse/fine adjust of V/div: nope.
6. Nope
7. Nope
So, one down, six to go. Especially the split screen and a smart way to browse the capture memory would be very nice.
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Honestly, though I didn't test excessively, my impression was that the updated firmware contains only bugfixes (crash in FFT, trigger on period), but there are no new/improved features except the virtual keyboard. E.g. there is definitely no windowed view for zoom mode (just main/set/zoom, which is ok, but a little inconvenient). Also the "show all" measurement window is still opaque and there are no statistics (mean/min/max/sdev) available for measurements. No triggering on both edges either, the dot mode is nonsense as it doesn't show the sample points etc.
For the moment, the Owon SDS line is still pretty interesting in this price range due to the large screen, large (semi-)fullspeed memory and generally good hardware design. But unfortunately, Owon missed the chance to considerably improve the software side of the SDS line in the last months to get a really outstanding product while the other manufacturers update their product lines.
So it will be interesting to see how the SDS line can hold up against the Rigol DS2000 when it becomes available in three or four months.
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So it will be interesting to see how the SDS line can hold up against the Rigol DS2000 when it becomes available in three or four months.
True, although judging by the published specs of the DS2000 (waveform capture rates up to 50k wfms/s), I suspect it will be closer in price to the Agilent 2000 X series than the Owon SDS line.
I wish more Chinese manufacturers would try to create scopes in the $500 - 750 midrange - of good design and build quality (like the Owon SDS7102) with large LCD screens, good connectivity, and a reasonable level of firmware features.
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Before update there was 2kSa/s maximum samplerate in scan mode. Now it is 5MSa/s.
"Repetitive" (some times called littlebit loosy as Equal-Time) mode is not very interesting feature in scope what have 1GSa/s (or 500MSa/s) what is classified as 100MHz oscilloscope. In history it was meaningfull. Example in 100MHz oscilloscope what have 10MSa/s maximum samplerate. Of course it need repetitive sampling for continuous signals, but this kind of oscilloscope is only <2-4MHz oscilloscope if talking single shot) Mostly but not always this Egu-Time is more like "feature of the ad men".
If look 100MHz oscilloscope what have 1GSa/s samplerate it is nearly so that there is misunderstooding if want this repetitive sampling mode. Yes in some rare cases if it is well done it may give something but veru marginal. Sometimes it make situation only more bad.
Owon have so wide front end that it may be very easy 250MHz oscilloscope (for 2 channels together) if there is implemented good repetitive mode. But why, it is 100MHz oscilloscope what reads in front panel, and it is 200MHz 1 channel and 150MHz 2 channel oscilloscope if look test data (but this is not quarateed by owon, it is only measured and true as long as they change something)
If I hope some real advantage to this scope, it is user adjustable hardware done adjustable brick wall filter in analog front end.
And variable (fine step) for V/div.
Windowed zoom... hmm nice for play, but not really needes for real working and just becouse this not windoved zoom is implemented so that it is very fast use.
In stop mode it is easy to go around long capture, just zoom out, horz position shift and zoom in. But if there is settable mark points and posibility to jump marks.. of course there is many things what are nice.
It store only .bin files but they can translate easy to .csv or .xls
Sin(x)/x it use this only with fastest timebases. Can no on/off.
But if have time and want "play". Becouse it have deep fast memory, it keeps 1GSa/s up to very low sampleartes. So it can look with lower speed, stop and zoom in. There is just lines between samples or only sampled dots. But this is just playing.
If afraid Sin(x)/x it is good to stay away from example Rigol what have been wrong implemented Sinx/x and it is better call it as some kind of "smooth".
I think here is nothing wrong:
http://i.cmpnet.com/planetanalog/2009/02/Sin(x)x_Agilent.pdf (http://i.cmpnet.com/planetanalog/2009/02/Sin(x)x_Agilent.pdf)
In signal quality Owon is good but FW have not so much features but all essentials for normal real working. (in this price class).
Most important is capturing quality. If we have garbage in oscilloscope generator, what to analyze?
But yes, if Owon have all Hantek or equal features in FW (without tons on bugs and better implemented ) and Owon HW, well... I want it and also price can be higher.
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If afraid Sin(x)/x it is good to stay away from example Rigol what have been wrong implemented Sinx/x and it is better call it as some kind of "smooth".
What is wrong with sin(x)/x on a Rigol and how much practical importance does this have? Is there an illustration of the fault somewhere?
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"Repetitive" (some times called littlebit loosy as Equal-Time) mode is not very interesting feature in scope what have 1GSa/s (or 500MSa/s) what is classified as 100MHz oscilloscope. In history it was meaningfull. Example in 100MHz oscilloscope what have 10MSa/s maximum samplerate. Of course it need repetitive sampling for continuous signals, but this kind of oscilloscope is only <2-4MHz oscilloscope if talking single shot) Mostly but not always this Egu-Time is more like "feature of the ad men".
If look 100MHz oscilloscope what have 1GSa/s samplerate it is nearly so that there is misunderstooding if want this repetitive sampling mode. Yes in some rare cases if it is well done it may give something but veru marginal. Sometimes it make situation only more bad.
I don't quite understand what you're saying here, but equivalent time sampling is hardly a 'feature of the ad men' - it's a well-known sampling technique for repetitive signals (http://www.cbtricks.com/miscellaneous/tech_publications/scope/sampling.pdf (http://www.cbtricks.com/miscellaneous/tech_publications/scope/sampling.pdf)) - and with ever-rising clock speeds on MCUs, etc, it's very handy to have sometimes when you don't have a high bandwidth real-time scope. When I had the Rigol DS1052E, I used the ETS a few times for checking ~500MHz clock signals - and it worked fine.
Windowed zoom... hmm nice for play, but not really needes for real working and just becouse this not windoved zoom is implemented so that it is very fast use.
Yes, most 'features' are not really needed for basic work - they just make basic work a lot easier. Windowed zoom would help a HUGE amount for keeping track of your position when moving through records (see below).
In stop mode it is easy to go around long capture, just zoom out, horz position shift and zoom in. But if there is settable mark points and posibility to jump marks.. of course there is many things what are nice.
It's 'reasonably' easy to move around - it's just not easy to keep track of your location or to find events in a 10Mpt record - in fact, it's a big pain in the ass - as I think anyone who has used this scope and tried to do can testify.
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What is wrong with sin(x)/x on a Rigol and how much practical importance does this have? Is there an illustration of the fault somewhere?
https://www.eevblog.com/forum/general-chat/rigol-ds1000e-series-possible-errorfail-in-sin(x)x-interpolation/ (https://www.eevblog.com/forum/general-chat/rigol-ds1000e-series-possible-errorfail-in-sin(x)x-interpolation/)
I don't quite understand what you're saying here, but equivalent time sampling is hardly a 'feature of the ad men' - it's a well-known sampling technique for repetitive signals (http://www.cbtricks.com/miscellaneous/tech_publications/scope/sampling.pdf (http://www.cbtricks.com/miscellaneous/tech_publications/scope/sampling.pdf)) - and with ever-rising clock speeds on MCUs, etc, it's very handy to have sometimes when you don't have a high bandwidth real-time scope. When I had the Rigol DS1052E, I used the ETS a few times for checking ~500MHz clock signals - and it worked fine.
It's a fine strategy, all the big brands use it to achieve high bandwidths on scopes only sampling in the kS/s range, assuming you have the front-end bandwidth to match and design the trigger circuit so the trigger noise is low enough to make the fast equivalent sampling rate meaningful.
I guess you could use it to look for the presence of 500 MHz signal on a 50 MHz scope, but since amplitude accuracy and signal fidelity are going to be crap anyway, wouldn't a cheap 1+GHz frequency counter achieve the same? A more accurate measure of amplitude could be achieved with a cheap RF diode detector probe.
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I guess you could use it to look for the presence of 500 MHz signal on a 50 MHz scope, but since amplitude accuracy and signal fidelity are going to be crap anyway, wouldn't a cheap 1+GHz frequency counter achieve the same? A more accurate measure of amplitude could be achieved with a cheap RF diode detector probe.
As I wrote, it's handy to have it sometimes, but it's not something that couldn't be done better with another piece of equipment (if you happened to have that piece of equipment laying around). Just like the FFT feature - or many features, when you come to think about it.
Anyway, in my list of 7 features I wouldn't mind seeing implemented in Owon's firmware, it was the 3rd from the bottom - and in fact, I only really care about the top 4 - if Owon could implement those I would forget the other three.
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Here you can find RuiFeng (http://aoxunf127.w290.bizcn.com/e_Products2.asp?ClassId=57)
tiny datasheet pdf here (http://www.mediafire.com/file/b5czrf664qm7cz4/MXT2002.pdf)
Functionally it is afaik same as common known ADC08D500.
Some specs just littlebit better in original but...
Price difference may be ... just more than big.
Package is nearly same. (not exactly direct pin-pin becouse RuiFeng have added some N.C. pins to corners.
Color: Chip is black.
Thanks a lot. This is exactly what I searched for.
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Just got my 7102 via Saelig. S/N 71021209xxx, FW 2.5.1 Nice surprise: they included the VGA port option at no charge. Maybe all sellers are doing this now? $429 out the door seems like a steal to me.
With the thoroughness of the video review on this scope and all the posts it was nice to know what to expect. So far no surprises, working great. My trusty old Tek 2236 now has competition on the bench...
Chris
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Been trying to get the SDS1702 connected to a Win7 workstation via the OWON PC program. Consistently timing out when I try to "Get Data." Am waiting for reply from OWON ts but was hoping someone here has had LAN connectivity success.
Chris B.
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Been trying to get the SDS1702 connected to a Win7 workstation via the OWON PC program. Consistently timing out when I try to "Get Data." Am waiting for reply from OWON ts but was hoping someone here has had LAN connectivity success.
Chris B.
Maybe here is something. (http://owon.forumup.com/viewtopic.php?t=51&postdays=0&postorder=asc&start=0&mforum=owon)
If it is assumed that the LAN port itself is ok in scope there is your system LAN settings and this may need also that you set oscilloscope LAN settings. Your scope have newest user manual where is better LAN settings than first LAN version user manual. Version Mar 2012 you find here. (http://www.box.com/s/ttnjqo3ppc64azz1dv7y)
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Been trying to get the SDS1702 connected to a Win7 workstation via the OWON PC program. Consistently timing out when I try to "Get Data." Am waiting for reply from OWON ts but was hoping someone here has had LAN connectivity success.
Chris B.
I had same problem with my 8202 - and I think if you read about the PHYS address in the link provided above - you will be able to get it to work.
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Thanks guys, great help and nice to get the latest manual. Not sure why OWON is not hosting it on their own site yet (as of few days ago).
The LAN connection is now working. IP addresses were not matched correctly between workstn and DSO.
Thanks again!
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Not sure why OWON is not hosting it on their own site yet (as of few days ago).
Maybe you are looking wrong Owon site.
Owon have changed! Also new MAR 2012 user manual tell it wrong.
(newest paper manual they have correct it by label over old address)
Time ago Owon Head Quarter send information letter to distributors including also we, that Owon official internet address and email addresses have changed!
After 22.Feb.2012
Owon official internet address:
http://www.owon.com.hk/ (http://www.owon.com.hk/)
There are also downloadables.
After this day, every single oscilloscope what we have sell include this information note. (if we have not suddenly forget this note sheet from package)
(these sites may still be somehow under construction and and some inrmation may be missed etc)
-aghp
(http://i969.photobucket.com/albums/ae171/Xie_07/OWONLILLIPUT.jpg)
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Maybe you are looking wrong Owon site.
Yes you are right, I was looking at the old .cn site. Thanks again for your help.
Chris B.
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Hey just got the Owon SDS7102V with v2.5.1 firmware.
I have a 40khz square pulse fed into CH1. The 40khz is from an Arduino Uno microcontroller.
When looking at the signal on the oscilloscope, it seems like there is small noise on the peaks and the transition points, is overshooting a bit.
Is this normal? At my school's lab, they have Tektronix TDS2002, but I did not see any of these kinds of imperfections on their oscilloscope.
Seeing more is better?
And about the third picture, it seems like I have a 1MHz signal on the skin of my hand, haha. Where is that from?
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Compensate your probes...
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Tektronix have 60MHz BW and Owon have labeled by 100MHz but in practice it have over 200MHz BW and well under 2ns risetime.
Your Tektronix is maybe just nearly blind for this.
Also there are many posibilities to produce this overshoot in measuring system itself. Without further deep tests it can not also know if signal matching from source via probe is matched. With fast rising edges it is important to use high frequency practices even if square base frequany is low. Minimum it need you do not use probe GND wire. It need GND directly to tip head using some adapter or minimum this poor "spring" what arrive with probe.
In oscilloscope itself there is not this overshoot if looking frequency response flatness curve but it can easy produce in signal pathway from device under test to oscilloscope. Fast rising edges need perfect matched signal road, more perfect more fast rising. But now you have lot of faster oscilloscope what is this named Tektronix and you can see more these things also more what are coming from "ringing" proping.
First of all. With fast edges, do NOT use probe normal GND wire if you want do more perfect measurements.
For even more perfect measurements it sometimes need use other method than normal probe what come with oscilloscope. This probe is not bad but it have its limits with higher frequencies (with fast rising/falling signals)
Also overshoot is normal.
Look these pictures
http://socrates.berkeley.edu/~phylabs/bsc/Supplementary/Lab1/xyz_scopes.pdf (http://socrates.berkeley.edu/~phylabs/bsc/Supplementary/Lab1/xyz_scopes.pdf)
Specially side 37.
Then: this Tektronix oscilloscope have only 2.5k memory.
What is samplerate for this your measurement with this tektronix?
(I can see in picture you have used 10k memory and you get 200MSa/s
I do not know what is Tektronix samplerate for same horizontal speed using 2.5k memory but I suppose it is 50MSa/s.)
With 50MSa/s Nyquist "wall" is 25MHz. In this case it is not 60MHz oscilloscope. With this samplerate in use and with Tek/Hp simplified thumb rules it is as 3 - 10MHz realtime oscilloscope. Now if it see this fast rising signal it produce lot of aliasing and with square wave it can see specially in corners. (wobbling corners)
Final note. Probe is good antenna for pick up many many RF signals and noises from enviroment.
It can use as EMI detector antenna if connect probe GND wire to tip. it is nice loop antenna. With this antenna you can go Owon backside or near your laptop power adapter...
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Compensate your probes...
In picture there is 2us/div and overhoot peak is more like <100ns-200ns than thousend time slower.
Probe calibration is LF compensation. But also of course it need be well adjusted.
(some nice Agilent and Tektronix probes have also compensation (adjustment) for fast edge response but they are not normally user available (inside probe head) and adjusting these need also equipments for adjusting. It can not do with normal "probe adjust" signal from scope front panel.)
Probe cal signal is 1kHz slow rising square. With this signal can not do, or even see edge response or make this kind of adjustments. (and also these probes have not these adjustments) User adjust is just low frequency compensation. (aka "probe calibration" )
Some good reading about probes(Tektronix) (http://aries.ucsd.edu/najmabadi/CLASS/COMMON/ABC-probe.pdf)
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I've received a brand new SDS7102 today and I'm totally disappointed...
Serial number is SDS71021209***, FW 2.5.1.
At first three minor issues:
1. Through a hole on the bottom I've seen a cheap NEC relay, the same model which was used on oldest HW. I didn't disassembled the oscilloscope, so I don't know are other relays also NEC.
2. There is some noise on VGA signal. Not too hight.
3. Weak vibration from fan.
But the real problem is a coupling selection of CH1. It seems that the optocoupler always stays in semi-opened state.
I've recorded a video with both probes connected to "Probe Comp" output: MVI_2771.mkv (https://www.youtube.com/watch?v=yq-fPGCLLbQ#)
As you can see the CH2 works good, but AC/DC coupling mode on CH1 doesn't work correctly.
The video was recorded few hours ago. Now the waveform looks good in DC mode, but still does not switches to AC mode correctly (I've made self calibration several times, maybe this may be a reson why in DC everything is fine).
But... sometimes (very rarely) it switches to AC and shows a correct waveform. If it was switched to AC successfully, a waveform looks fine after any manipulations with V/div or any other controls and even after self calibration. But when I switch it from AC to DC and then from DC to AC, the problem appears again.
It is realy confusing. Looks like a broken relay, but I think that there is an optocoupler, because I hear no "click" when switching between AC/DC modes on CH2 which works fine.
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AC/DC is not mechanical relay.
NEC relay what you see through bottom hole near right down corner is nothing to do with CH1 and CH 2 channels signal pathway. This relay what you see can be normal relay, And also, what is real problem with this NEC relay. Nothing. Why it is not problem in Hantek or Rigol but if it is inside Owon and out from primary signal pathway it is just now problem?
Fujitsu relay is just littlebit better than this NEC model. Difference is not big. It not any problem if this NEC is just used also later in new HW version - just becouse it is not problem.
I'm very interesting to see real data about "problem" with NEC relays. Some real data, where.
It was only opinion that Fujitsu relay is littlebit better but it was just mutua. Example becouse this datasheet really read that it is for RF purposes. But I have not see any true measured data so that can compare what is exactly difference if only variable is this relay.
Looking trough this hole you can not see these CH1 and CH2 band relays. These band relays are under front end RF shields and they are solder closed.
If you think your oscilloscope is defect just call seller and if seller do nothing call Owon service.
(if there is real warranty fail issue (and specially if situation is "arrived as fault" you may get Owon fly ticket... (courier) and they exchange it or repair it)
FAN: small vibration is possible but if it keep bad noise or if vibration is bad then it is problem.
If it is damaged factoru oscilloscope assembling phase it later may go more bad becouse bad unbalance very soon destroy sleeve bearings.
With some co-work with some other person also I have talked to Owon factory that they need change handling routines related to FAN. One wrong handling when assembly oscilloscope and FAN is garbage. If fan example drops from hand to floor... never assemble it. It must put to garbage collection.
It is very pity there are lot of resellers who sell these just as nice boxes. They do not check anything, just only buy in and sell without any work. Some sellers even do not know what is oscilloscope. It is only nice carton box what have some price.
If you have problem, EEVblog do not repair it. Contact first seller and if not real help, contact Owon (remember there is still delays due to Qing ming festival) And use these addresses what you find Owon HK sides or call to Owon service phone.
But also I suspect some issue in using... for close all other posibilities out and proof that there is real problem in channels.. you can PM me and I may help by giving exact simply orders you follow for tiny tests.
I can not primise immediate "as fireman" answers but with my own timetable.
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I've ordered it to AideTech to USA address and then it was shipped to Ukraine. AideTech stated "14 days money back, buyer pays return shipping".
Shipping to Ukraine took more than 14 days, so I cannot return it back to seller :(.
I've contacted OWON support, see what they offer.
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Also a distance from me to the seller is about 15000km, so the shipping may be too expensive and there may be I have to pay customs duty when they send it back to me.
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@EU1 - I don't know about customs in the Ukraine, but everywhere in the West: when you send an item for repair (to be returned after) with the necessary paperwork, there are never any custom duties for the return. I'm pretty sure the rules would be the same there.
Maybe you got the scope sent via the US to avoid customs duty when you imported it, but the Ukrainian customs won't know how you got it into the country (or if you bought it in Ukraine) when you are sending it out for repair and return.
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Also a distance from me to the seller is about 15000km, so the shipping may be too expensive and there may be I have to pay customs duty when they send it back to me.
I cant understand why you purchased from a seller so far away from you when you have dealers closer.
A eev member "aghp" is a Owon dealer based in Finland and he tests all Owon scopes before shipment to the customer, so you can be sure the product is A1 when received.
Also he is a pleasure to deal with and will answer any question you may have with the product.
I wish you the best of luck with getting your scope returned as the Owon SDS scopes are great value and an excellent product just a shame you purchased a faulty one.
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Hello!
I live in Russia and I have bought SDS8202 #SDS82821149*** in middle of February. After a week of lazy using I niticed very loud noise inside (FAN noise). I have tested it about CH1 noise - and found it. So I have written to OWON email from new (.hk) site.
Then I have written again..
Then again..
So, I have no answer from OWON for a month. Not even "this is your problem, go away". Just nothing.
I defenitely don't want to send oscilloscope so far wawy, because it means two or three monthes without it.
What should I do to get new FAN and plastic detail to repair to be sent to me via post mail (as it was with another people here)?
Is email "info -at -owon.com.hk" working?
Thanks in advance!
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In China just have end Qingming festival time and I think yesterday they have started come back to working?
with this email address normally they answer inside 24 - 48hour.
Small posibility is that "some" firewall stop your email or receiver mailbox is filtering it to garbage.
Also look that your computer do not have any kind of virus infection what may add something... Also check that your character code settings are ok. (UTF-8 is e mostly ok).
If you still have problem to contact Owon I can try help you, first I can try forward your message to Owon.
But, first. If I buy bicycle and then there is some problem. First I contact seller, not factory who have made it. Your seller have contact to Owon and seller can also help you or least try help?
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Also a distance from me to the seller is about 15000km, so the shipping may be too expensive and there may be I have to pay customs duty when they send it back to me.
I cant understand why you purchased from a seller so far away from you when you have dealers closer.
A eev member "aghp" is a Owon dealer based in Finland and he tests all Owon scopes before shipment to the customer, so you can be sure the product is A1 when received.
Also he is a pleasure to deal with and will answer any question you may have with the product.
I wish you the best of luck with getting your scope returned as the Owon SDS scopes are great value and an excellent product just a shame you purchased a faulty one.
Because a simplest way to buy this model is order it from USA. There are many aspects - shipment, customs clearance, etc :(.
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Yesterday I wrote that the CH1 works good with DC coupling but there is a problem with AC.
Today it works good with AC coupling, but cannot switch to DC.
There is a +10...20mV offset on CH1 in AC coupling when both channels are connected to probe compensation output, probably it is caused by optocoupler leakage. When I switch CH1 to DC, waveform shifts about 20...40mV up.
So I guess that the optocoupler itself is a root cause. Also it is possible that there is a problem with corresponding digital output with controls the optocoupler or with related components (probably there are at least a transistor and resistors which also are under a cloud).
I communicating with OWON, truly hope they will propose some adequate solution for my problem.
Also I've notes some low frequency noise caused by LCD backlight supply.
It increases when I decreased the display brightness.
Noise level on both channels is the same. On the screenshot below CH1 is open (probe is not connected) and CH2 input is connected to the ground with a short wire near the BNC connector.
Thus a noise is present only if an input is open.
Probably it is not an issue, because noise peak-to-peak amplitude it less than 1mV. Just want to ask is such noise typical for other SDS7102?
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NEC relay what you see through bottom hole near right down corner is nothing to do with CH1 and CH 2 channels signal pathway. This relay what you see can be normal relay, And also, what is real problem with this NEC relay. Nothing. Why it is not problem in Hantek or Rigol but if it is inside Owon and out from primary signal pathway it is just now problem?
Fujitsu relay is just littlebit better than this NEC model. Difference is not big. It not any problem if this NEC is just used also later in new HW version - just becouse it is not problem.
I'm very interesting to see real data about "problem" with NEC relays. Some real data, where.
It was only opinion that Fujitsu relay is littlebit better but it was just mutua. Example becouse this datasheet really read that it is for RF purposes. But I have not see any true measured data so that can compare what is exactly difference if only variable is this relay.
Looking trough this hole you can not see these CH1 and CH2 band relays. These band relays are under front end RF shields and they are solder closed.
Of course this is a trigger input relay.
It would be great if somebody know which relays they used now in channel front-ends.
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So I have written to OWON email from new (.hk) site.
Then I have written again..
Then again..
So, I have no answer from OWON for a month. Not even "this is your problem, go away". Just nothing.
I defenitely don't want to send oscilloscope so far wawy, because it means two or three monthes without it.
What should I do to get new FAN and plastic detail to repair to be sent to me via post mail (as it was with another people here)?
Is email "info -at -owon.com.hk" working?
I've contacted them from my gmail account and they answered pretty fast. Thus "info -at -owon.com.hk" is definitely working :).
Actually I had a very good impression of the Owon support. I will describe this when my problem with CH1 will be resolved (now I have a reason to think that it will be resolved :) ).
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As I've stated before, I've contacted OWON and they offered a very nice solution for my problem with SDS7102.
At Monday midday they sent me a shipment by DHL and today I've already received a box (just 3 day to ship from China to Ukraine - it is amazing) with the perfectly packed mainboard with pillars installed and the FAN :).
Thus I very pleased with the OWON support. They always answered professionally and fast, even during weekend. Only a week has passed since I've contacted OWON regarding HW problem and today the problem is almost resolved (I've not replaced the board yet :) ).
I just made a cursory look and there are some changes comparing to my old board - it seems that a board they sent me is of newest HW revision.
I've noted that relays are again Fujitsu and TI's amplifier is used in the trigger channel (it seems that on they used some AD amp before, not sure because I was not disassembled the oscilloscope but just looked at the board through small holes on the case). And it seems that the trigger channel is significantly reworked.
Will see how it works when I will replace a board :).
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EU1, its good to hear you are getting results. The continuous revisions to their boards can get confusing, but at least if you can do your own service, it makes for a better scope in the end.
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Good.
If you do not have this it may help littlebit. (http://www.box.com/s/pvg1dqtdonx192p4os0m)
In Fan assembly look it is well centered. Other way later fan blades may hit this metal in some cases and make bad noise and soon destroy also bearings. (in Owon there is some workers who are loosy sometimes and fan may be not assembled correct. First time they start oscilloscope it may just be nice... later this noise may start specially if moving or turning scope when it is powered.
Relays.
In this scope NEC and Fujitsu relays are nearly as same value. Freq response and risetime and BW shape is nearly equal with both relays.
Sometimes availability just on right time for use in product assembly line may be also question...
Personally I like littlebit more these Fujitsu but without real data. Just becouse I like more F than N letter.. In Owon service and tests before sell, I have not yet meet any fail related to relays if they have been NEC or Fujitsu. (Note that in this Fujitsu relay serie is also RF version... but afaik, used versions are basic versions without extra "RF" mark. Also I know some oscilloscopes are continuously in heavy professional "everyday" use - no problems in relays, no problems in fan IF fan have been OK after our extra burn in tests.
Also we have tightened this fan quality control and we do not accept for sell any scope if we find signs about problem real problem.
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Good.
If you do not have this it may help littlebit. (http://www.box.com/s/pvg1dqtdonx192p4os0m)
Thank you. Nice manual.
I have two questions:
1. You warned to do not open display connector if it is not exactly necessary. I've worked with many types of ZIF flex cable connectors and never had problems with them. Is OWON's connector really not tough enough or it is just a warning for people who newer worked with such kind of connectors?
2. It seems that SDS has thought-out mechanical design, with holes for screwdriver in boards and Z-plate. Looks like I can just unscrew two screws on Z-plate, then unscrew three screws from mainboard through holes in Z-plate, and then remove Z-plate with display, PSU, adapter and main boards. Then I can replace mainboard without unscrewing adapter board and disconnecting the display. Have I missed something?
In Fan assembly look it is well centered. Other way later fan blades may hit this metal in some cases and make bad noise and soon destroy also bearings. (in Owon there is some workers who are loosy sometimes and fan may be not assembled correct. First time they start oscilloscope it may just be nice... later this noise may start specially if moving or turning scope when it is powered.
Looks like exactly my case. My oscilloscope worked about 15-30 hours, thus even if FAN bearing was initially in good condition, probably now it is damaged. Anyway, now I have a new one which I will center precisely :).
Relays.
In this scope NEC and Fujitsu relays are nearly as same value. Freq response and risetime and BW shape is nearly equal with both relays.
Sometimes availability just on right time for use in product assembly line may be also question...
Personally I like littlebit more these Fujitsu but without real data. Just becouse I like more F than N letter.. In Owon service and tests before sell, I have not yet meet any fail related to relays if they have been NEC or Fujitsu. (Note that in this Fujitsu relay serie is also RF version... but afaik, used versions are basic versions without extra "RF" mark. Also I know some oscilloscopes are continuously in heavy professional "everyday" use - no problems in relays, no problems in fan IF fan have been OK after our extra burn in tests.
Also we have tightened this fan quality control and we do not accept for sell any scope if we find signs about problem real problem.
I will check this when get home.
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:)
i got my new 7102 yesterday firmware seems to be 2.6
i did a quick calibration and function testings, it seems to be really great, around 0.5mv of noise on channel ...
but i just found this this morning ....
darn ! i have 1 stuck on green pixel !
is this warranty ?
is this common problem ?
i'm going to write to my ebay seller ...
EDIT: Added pic of stuckOn pixel, left bottom screen, just below the graticule
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I have two questions:
1. You warned to do not open display connector if it is not exactly necessary. I've worked with many types of ZIF flex cable connectors and never had problems with them. Is OWON's connector really not tough enough or it is just a warning for people who newer worked with such kind of connectors?
Exactly this. If write some help text it need take care about many different level peoples (also becouse privately I know some peoples who I was helping with this and this also was in mind when I write littlebit "over" carefully. If people have not knowledge about this kind of connectors and never handled these connectors, it can easy break.
2. It seems that SDS has thought-out mechanical design, with holes for screwdriver in boards and Z-plate. Looks like I can just unscrew two screws on Z-plate, then unscrew three screws from mainboard through holes in Z-plate, and then remove Z-plate with display, PSU, adapter and main boards. Then I can replace mainboard without unscrewing adapter board and disconnecting the display. Have I missed something?
I think you have not missed anything, but also if unscrew adapter board it do not need disconnect display.
Original old version was lot of different. Main board different, front panel big board and small boards different and adapter board different and even power supply littlebit different.
Also old version did not have ribbon cable between main board and front panel.
Also it was originally for front end (service) adjustment with minimum work time using service cable between adapter and main board. (original old version did not have ribbon cable between front panel and main board...
My way is only one way, there are others maybe better or just parallel ways.
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:)
i got my new 7102 yesterday firmware seems to be 2.6
i did a quick calibration and function testings, it seems to be really great, around 0.5mv of noise on channel ...
but i just found this this morning ....
darn ! i have 1 stuck on green pixel !
is this warranty ?
is this common problem ?
i'm going to write to my ebay seller ...
This is first time I hear pixel problem (in Owon SDS)
These Chimei-Innolux panels have been very good quality.
It is NOT common problem in Owon oscilloscopes.
(btw. Tekway - Hantek use these same TFT panels but different size)
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Pixels die sometimes really . I had a Samsung LCD screen die completely within 2 years ::)
The samsung LCD panel i am typing had a dead green pixel from the start , but since it's a high reso one i usually can't see it :-[
That said , contact your ebay seller .
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ZAP
darn ! i have 1 stuck on green pixel !
This is first time I hear pixel problem.
These Chimei-Innolux panels have been very good quality.
It is NOT common problem.
I put a pic of it in the original message i'm gonna take a better pic tomorrow !
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i put my scope to some test tonight and i found 2 things :o :D
bad first i discover i have a faulty probe, when the probe lays flat no problem, it also bends in 3 directions, but a really small bend in the other and i got full noise ....
here a video of that ...
http://s1114.photobucket.com/albums/k539/n45w73/dev%20stuff/?action=view¤t=MVI_9868.mp4 (http://s1114.photobucket.com/albums/k539/n45w73/dev%20stuff/?action=view¤t=MVI_9868.mp4)
good new it is fun to have a scope ! :P
here a small video of PWM of an hbridge in red and voltage of the neg pole of the motor in yellow.
it is a small low standard no torque 50mA motor
http://s1114.photobucket.com/albums/k539/n45w73/dev%20stuff/?action=view¤t=MVI_9862.mp4 (http://s1114.photobucket.com/albums/k539/n45w73/dev%20stuff/?action=view¤t=MVI_9862.mp4)
strange traces ;), a bit because there was no load on my cheap motor so i choose the worse frequency of pwm and also because of the "fast" refresh of the scope who stacks many trace together on the screen ...
that bridge will need a lot more study for sure ;)
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Stuck pixels maybe a mechanical issue, rub around it or press on it with your finger and see what happens.
See more here:
http://en.wikipedia.org/wiki/Stuck_pixels#Stuck_versus_dead_pixels (http://en.wikipedia.org/wiki/Stuck_pixels#Stuck_versus_dead_pixels)
ZAP
darn ! i have 1 stuck on green pixel !
This is first time I hear pixel problem.
These Chimei-Innolux panels have been very good quality.
It is NOT common problem.
I put a pic of it in the original message i'm gonna take a better pic tomorrow !
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I've replaced the board but had faced with another issue: there ia a large interferences caused by backlight LED DC-DC converter. Earlier on old board I've discovered some weak interference from backlight (https://www.eevblog.com/forum/product-reviews-photos-and-discussion/review-of-owon-sds7102/645/ (https://www.eevblog.com/forum/product-reviews-photos-and-discussion/review-of-owon-sds7102/645/)), but it disappeared when I connected a 50 Ohm BNC terminator or probe, even when I connected a 10kOhm resistor or any signal source with any output impedance there was no interference, so it did not affected measurements because it was visible only when nothing is connected to inputs.
I've compared peak level of noise of my oscilloscope with screenshots which other people shared on the Internet and found it is about the same. Thus I've considered that it is OK, now I have reasons to gues that it is not OK :(.
With new mainboard interference is much larger and they are enlarged when I connect terminator to input. I've installed the old mainboard again and see the same very small interference visible only on open input. Thus it is not due to incorrect installation - because I swapped boards few times and always I get negligible interference with old board and large interference with the new one.
The problem appears when powered from battery or from AC mains. So it is definitelly not a PSU problem.
I've made screenshots with new boards. X10 probe configuration is selected for both channels. I just forgot to switch it to X1, thus V/Div readings on the screen should be divided by 10 to get the actual input sensitivity.
An interference on both channels is the same. I leave CH1 open (no probe connected) and connect 50 Ohm BNC terminator to CH2 to show that 50 Ohm terminator increases an interference.
NewBoard_1.png: CH1 is open, CH2 shorted to ground through 50 Ohm BNC terminator, brightness is 0%.
There RF noise extremely low for 2mV/Div sensitivity. Seems that it is even much lower than a noise on the old board.
But there is a terrible 30kHz interference from backlight LED driver.
NewBoard_2.png: CH1 is open, CH2 shorted to ground through 50 Ohm BNC terminator, brightness is 100%.
30kHz noise is much lower comparing to an interference with 0% brightness, but it is still present and spikes occasionally appears.
NewBoard_3.png: FFT for CH2 which is shorted to ground through 50 Ohm BNC terminator, brightness is 0%.
30kHz interference with harmonics is clearly visible.
NewBoard_4A.png, NewBoard_4B.png: Even with low sensitivity 30kHz interference is clearly visible. With 2V/Div interference is higher than with 1V/Div. Thus interference comes rather through power line than through input.
It doesnt look like a mainboard issue, because there are a lot of DC-DC converters on the adapter board and on the mainboard itself and only an LCD backlight step-up causes interference. I guess that a mainboard of new revision is just more sensetive to low-frequency ripple on supply voltages rails and a real problem is a LCD backlight step-up on the adapter board or new mainboard has some compatibility issues with old adapter board (I'm not sure that OWON changed adapter board, this is only an assumption). There are a lot of changes in analog and power management parts on the new board comparing to my old one.
Thus I would like to ask people who have SDS7102 - have you any signs of 30kHz noise with visible low display brightness with open input (no probes connected)?
Because I have this noise on two mainboards of different revisions - on old 1209*** it is wery weak and produces no visible impact on measurements, but it is still visible when nothing is connected to input BNC, especially on FFT. On new board (1211****) interference level raises when I connect a probe. I've recorded a video, you can see that on 2V/Div with an input is connected to probe compansation output an interference just makes any precission measurements impossible (while on 1V/Div it is much lower):
MVI_3023_Interference.mkv (https://www.youtube.com/watch?v=thldpvawsAw#)
And the second strange thing - I've noted some strange behavior of external synchronization input when it is configured to trigger on falling signal edge, on old mainboard the trigger works fine, so owners of 1211**** devices, please check check is this issue appears on your devices. On the video both ext trigger input and a channel input are connected to probe compensation output and an AC coupling is selected for trigger and channel input itself:
MVI 3025 Trigger (https://www.youtube.com/watch?v=02iTe5TiX0A#)
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I think you have not missed anything, but also if unscrew adapter board it do not need disconnect display.
When I disassembled the unit I've discovered that there is a thing that I've missed - the BNC connector on the real panel prevents removing the mainboard without unscrewing the adapter board. So the way described in your manual probably is a simplest possible. At least I did not found any better way :).
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This disassembly is possible also other way but it need small trick with Z-plate.
About backlight control.
It is described here (old) but sorry, most txt is with finnish lang. (http://owon.forumup.com/viewtopic.php?t=23&mforum=owon)
After this there is small change in PWM frequencies and later they also have changed current control reistor and typical now is 1R0. No need anymore change this resistor. (older some systems have been too dim becouse current was too low due to wrong resistor and due to wrong thinking in design = it need be current, not voltage what need adjust ok so that it meets Chimei-Innolux specifications for driving back light LED's.
Here this old (obsolete) pic
( it is explained there with finnish language what is 2nd difficult after chinese what is number 1.))
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This disassembly is possible also other way but it need small trick with Z-plate.
About backlight control.
It is described here (old) but sorry, most txt is with finnish lang. (http://owon.forumup.com/viewtopic.php?t=23&mforum=owon)
After this there is small change in PWM frequencies and later they also have changed current control reistor and typical now is 1R0. No need anymore change this resistor. (older some systems have been too dim becouse current was too low due to wrong resistor and due to wrong thinking in design = it need be current, not voltage what need adjust ok so that it meets Chimei-Innolux specifications for driving back light LED's.
Here this old (obsolete) pic
( it is explained there with finnish language what is 2nd difficult after chinese what is number 1.))
On my board 1 Ohm resistor is soldered and the display is rather too bright for me even with 0% brightness.
Brightness adjustment works. The problem is a 30kHz noise which comes from the backlight step-up to input channels. I know that you worked with many SDS7102 units, have you seen any 30kHz noise with brightness less than 100%?
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Thus I would like to ask people who have SDS7102 - have you any signs of 30kHz noise with visible low display brightness with open input (no probes connected)?
Because I have this noise on two mainboards of different revisions - on old 1209*** it is wery weak and produces no visible impact on measurements, but it is still visible when nothing is connected to input BNC, especially on FFT. On new board (1211****) interference level raises when I connect a probe. I've recorded a video, you can see that on 2V/Div with an input is connected to probe compansation output an interference just makes any precission measurements impossible (while on 1V/Div it is much lower)
i got Vp 0.640mV of that 30kHzon both channels with backlight 0%
a little bit less noise at 80%
and i got Vp 0.400mV at 100%
with ch1 probe grounded on itself and put away (didn't test for ch2)
i got Vp 1.280mV on ch1 30kHzon with backlight 0%
i got Vp 0.880mV on ch1 30kHzon with backlight 100%
i pick noise, with probe grounded , from the top of the screen around Vp10mV
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i pick noise, with prove grounded , from the top of the screen around Vp10mV
Owon backlight produce littlebit noise specially if other than 100% brightness.
Also after some peoples talk about LCD backlight audible high pitched noise what can listen with human ear Owon made small changes.
It was really pity they did this change. (change was made in FW changing EN signal (PWM)) Now it can dim only littlebit. 0% is really bright now. 0-100% is now nearly as 80% - 100% before this change.
Right solution is in HW but then it do not help these peoples who allready can listen this "noise" becouse some very rare unit produce it in some component as some kind of interference/resonance. (propably one inductor).
With open CH input I can find around <1mV around 30kHz noise. But who measure anything with open input. Do it really affect real measuremets if you use the normal working practices, and good measurement practices. Of course, it require also some experience. In the laboratory, one of the most difficult things are to know error sources and be able to avoid them. It helps the most extensive experience and adequate knowledge. It must also be able to assess what kind of things are really important and what not.But yes, it need littlebit care if do some very sensitive measuremets that do not pollute tests with enviroment RFI/EMC
Also oscilloscope itself is some source and it also radiate noise field. But lot of care need if lab have schwitch mode small things as example energy saving lamps, laptop, laptop power supply, and many other this kind of things in today electronic equipments. Example if take normal Tektronix analog 2235 oscilloscope (what is not at all bad). It is still terrible emi noise source and still it is all inside aluminium case. Its power supply pollute oscilloscope inside and lab room outside. Also it radiate lot of to enviroment. Becouse this, they have made also MIL version about same scope with better EMI shielding, even CRT front have metal grid.
Probe is as antenna. If connect GND to center tip this is nice near field loop antenna. It is grounded ONLY if think pure DC. It is not grounded at all if look it with RF eyes.
It is "poor man" easy made near field RFI probe.
Connect probe GND wire to probe tip it make D shape loop. Turn probe to 1:1.
Try example with laptop, try find example backlight inverter noise. I move it around laptop and Lenovo T series near right bottom corner of display it give around 2000mV peak to peak around 58kHz.
For many purpose better loop antenna can easy do. 50 ohm loop antennas for near field proping of noise is easy made using semirigid coaxial (example from dismantled equipment "waste").
These are very handy for example spectrum analyzers.
(these 50 ohm loops are not very good for oscilloscope what have 1M input)
Here is random example picture collected from internet.
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voidptr, rf-loop: thanks for your investigations, so the interference presence seems to be a normal case.
It is really strange, because it can be easily avoided by reducing a dimming frequency to be less than 2kHz.
30kHz is a too high dimming frequency for G5126 step-up converter and this is even explicitly defined in the datasheet (http://www.gofotech.com/upfiles/201026105539.pdf (http://www.gofotech.com/upfiles/201026105539.pdf)):
LED dimming control is pos sible by forcing PWM signal to EN pin. When the power-on or start up with EN pin, softstart function works, however, after that, if the EN pin is set as “L” and set EN pin “H” again during the shutdown delay time, softstart function is disabled and starts up fast to normal mode, therefore 200Hz to 2kHz PWM signal is standard. By the EN pin input, LED turns on and off. Average LED current varies depending on the duty cycle of EN input. Too high frequency PWM signal is not ffective because of its delay.
Of cource, lower frequency may cause acoustic noise to be audible, but but this is only 0.2A DC-DC converter, such low power converters usually stay silent on any frequency if a type of inductor is chosen properly.
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Connect probe GND wire to probe tip it make D shape loop. Turn probe to 1:1.
Try example with laptop, try find example backlight inverter noise. I move it around laptop and Lenovo T series near right bottom corner of display it give around 2000mV peak to peak around 58kHz.
Of cource for all measurements with grounded input I've used a 50 Ohm BNC terminators or just a short piece of uninsulated wire inserted into the BNC connector.
As for inverters, I placed a probe near my laptop's backlight inverter and get something about 20V RMS AC voltage :). Because there is even no EMI shild on inverter board, just a piece of plastic covers switch transistors and HV transformer.
Owon backlight produce littlebit noise specially if other than 100% brightness.
Also after some peoples talk about LCD backlight audible high pitched noise what can listen with human ear Owon made small changes.
It was really pity they did this change. (change was made in FW changing EN signal (PWM)) Now it can dim only littlebit. 0% is really bright now. 0-100% is now nearly as 80% - 100% before this change.
The PWM duty cycle for 0% brightness is about 35%. I guess that it is not easy to get a low brightness with 30kHz PWM.
If the frequency will be reduced to 2kHz or less the brightness will be much more controllable and a soft-start function will operate making a G5126 much more "silent".
Really hope that OWON will correct this in new FW.
And, guys who have newer HW (probably all boards with FW 2.6.2), please check the external trigger channel operation:
Just attach probes to CH1 and EXT TRIG inputs (ensure that the switch on the trigger probe is in the X1 position) and connect both probes to the PROBE COMP output. Then in CH1 menu select AC coupling, in trigger menu select AC coupling, trigger source EXT/5 and triggering by falling edge (H4 button - "Slope"). Then select 1us/div sweep and by adjusting trigger level with the knob from -3V to +3V see is the trigger fires exactly at signals edge.
On my the following video you can clearly see that the trigger fires with a delay from hundreds of ns to tens of us:
MVI 3025 Trigger (https://www.youtube.com/watch?v=02iTe5TiX0A#)
I just want to know is it a specificity of my new board (1211****) or all new boards work with falling edge trigger with such delay. On old board (1209***) I was not noted this.
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The PWM duty cycle for 0% brightness is about 35%. I guess that it is not easy to get a low brightness with 30kHz PWM.
If the frequency will be reduced to 2kHz or less the brightness will be much more controllable and a soft-start function will operate making a G5126 much more "silent".
Really hope that OWON will correct this in new FW.
In early version, this LCD backlight control works just fine!
It need return back. Why they make change to good. This is interesting question.
It is good that manufacturer listen customers. They of course need collect opinions and reports about bad things, bugs etc.
But there it go wrong if too fast make changes just as in "panic". Many peoples want so many things. There need be calm in manufacturer side and do ONLY changes what are really examined and tested and studied with experienced professionals before change. Also need carefully think if change is ok. This LCD backlight is just good example about wrong reaction after customers feedback. It need study in manufacturer laboratory first and really think what is good solution (or do it need anything) but control better example inductors quality or some other component.
So, I hope Owon return this LCD control just back so that it works like it works in early "not improved" HW version but using right (1R0 - 1R2) current monitor resistor value and original part of FW for control.
Second. Why they have make changes to HW now? 1149xxx - 1209xxx is best HW and it works well. Why change good?
It is nearly as "repairing" (or many times adjusting) unit what have not any fail or problem.
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here an update with my Owon scope's problems
bad stuck on green pixel :
i got update from my ebay seller and also from Owon's service, 1 bad pixel is NORMAL thing and is not a defect...
my seller said i need a bunch of them to be considered has a defect...
so people be aware of that you may end up with a bunch of them :o
bad probe:
for my probe defect, they said they will ship me a replacement ...
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here an update with my Owon scope's problems
bad stuck on green pixel :
i got update from my ebay seller and also from Owon's service, 1 bad pixel is NORMAL thing and is not a defect...
my seller said i need a bunch of them to be considered has a defect...
so people be aware of that you may end up with a bunch of them :o
bad probe:
for my probe defect, they said they will ship me a replacement ...
Yup . Samsung does the same thing , they wouldn't change my panel when i asked them about a few dead pixels on a full hd 37" set , only until the whole screen died . Maybe your lcd was manufactured quite a long time ago , some new LCD's have some dead pixels and it takes time for them to appear eventually .
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here an update with my Owon scope's problems
bad stuck on green pixel :
i got update from my ebay seller and also from Owon's service, 1 bad pixel is NORMAL thing and is not a defect...
my seller said i need a bunch of them to be considered has a defect...
so people be aware of that you may end up with a bunch of them :o
bad probe:
for my probe defect, they said they will ship me a replacement ...
all LCD manufactures have a dead pixel policy. Among the worst are Apple and Acer. My Thinkpad had 4 in the middle and would not exchange the display. But then another 10 went - and they had to. (one block of 6 = screen replacement)
But they change their "Dead Pixel" policies very often - possibly based on the average number of defective pixels + 3 :-)
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stop comparing cheap enduser product manufacturers (and their TFTs) with industrial TFT.
Innolux can deliver, when you buy at least grade A, displays with no dead pixels.
It seems Owon is trying to save few cent and using cheaper displays, i would send
such DSO back. I don't trust such manufacturers, who knows what quality other parts are.
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stop comparing cheap enduser product manufacturers (and their TFTs) with industrial TFT.
Innolux can deliver, when you buy at least grade A, displays with no dead pixels.
It seems Owon is trying to save few cent and using cheaper displays, i would send
such DSO back. I don't trust such manufacturers, who knows what quality other parts are.
This kind of pixel fail in Owon is quite rare. I have not seen any. Just also same for Hantek what I have seen many.
Up to this day I have not meet any stuck on pixel as fail.
afaik, both manufacturers use Innolux industrial grade TFT panels.
All TFT I have seen in Hantek they are same Innolux panels but different dimensions and pixels. 800x480 in Hantek and same panel type but 800x600 in Owon. (becouse different using of display area they are quite equal in oscilloscope display meaning. (owon use fixed area of menu bottom of screen so signal area is very near same)
Display panel quality is equal. (if Owon have just changed display this I do not know)
(today Innolux is Chimei-Innolux)
Contact seller (if seller is ok with Owon they can negotiate it with Owon, it must not be end user problem if reseller is real ok) or directly Owon hk service and tell failed TFT.
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stop comparing cheap enduser product manufacturers (and their TFTs) with industrial TFT.
Innolux can deliver, when you buy at least grade A, displays with no dead pixels.
It seems Owon is trying to save few cent and using cheaper displays, i would send
such DSO back. I don't trust such manufacturers, who knows what quality other parts are.
This kind of pixel fail in Owon is quite rare. I have not seen any. Just also same for Hantek what I have seen many.
Up to this day I have not meet any stuck on pixel as fail.
afaik, both manufacturers use Innolux industrial grade TFT panels.
All TFT I have seen in Hantek they are same Innolux panels but different dimensions and pixels. 800x480 in Hantek and same panel type but 800x600 in Owon. (becouse different using of display area they are quite equal in oscilloscope display meaning. (owon use fixed area of menu bottom of screen so signal area is very near same)
Display panel quality is equal. (if Owon have just changed display this I do not know)
(today Innolux is Chimei-Innolux)
Contact seller (if seller is ok with Owon they can negotiate it with Owon, it must not be end user problem if reseller is real ok) or directly Owon hk service and tell failed TFT.
At least for the SDS7102T as for the MSO8102 it's the same as hantek . God i still remember the days of SVGA ::)
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ZAP
Contact seller (if seller is ok with Owon they can negotiate it with Owon, it must not be end user problem if reseller is real ok) or directly Owon hk service and tell failed TFT.
my seller told me i need at least 3 dead stuck on pixels to be considered a bad lcd, so else i will pay for exchange and there is no warranty i will get one without bad pixel ...
so i think i can live with it, until i have enough money to buy a scope from a better company...
8)
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At least for the SDS7102T as for the MSO8102 it's the same as hantek . God i still remember the days of SVGA ::)
Owon do not have SDS7102T model. If you mean SDS7102V (this whole thread is for SDS7102) it have different display than MSO8102 is MSO8102T and it have 8" 640 x 480 display.
SDS7102 and SDS7102V have 8" 800x600 (and this is SVGA)
What was your point?
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At least for the SDS7102T as for the MSO8102 it's the same as hantek . God i still remember the days of SVGA ::)
Owon do not have SDS7102T model. If you mean SDS7102V (this whole thread is for SDS7102) it have different display than MSO8102 is MSO8102T and it have 8" 640 x 480 display.
SDS7102 and SDS7102V have 8" 800x600 (and this is SVGA)
What was your point?
My point was . THERE ! The SDS7102 had more pixels then the hantek screens although being the same and the mso8102 having a vga display .
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ITs now been over 8 months since MARMAD started the review on this scope , and with such along 45 page post on it i hope that MARMAD , may do an updated review for Youtube
Taking into account his experiences ,which would include
1. review OWON relating to software updates and their approach / frequency of updates thus far ,
1a. OWON policies on bad pixels on screens and warranty returns and how they go about it
2. hacks if any ,
3. general measuring issues that have shown up since review
4. reflect and add information from some who have contributed to this very long post , ( that i have read from the start).
5. the wish list of features that owon have indicated may be included in future updates if any
Based in no small part to this thread and the review done by MARMAD , I too have just purchased OWON SDS7102V scope as of 4 days ago from the Ebay seller SMTZONE , who from accounts on this thread is a good online dealer.
I looking forward to seeing this scope and doing testing to see if any of the highlighted issues that have been seen are still in the the most upto date stock being sent now.
It would be VERY VERY handy indeed if a summery of the testing details ,contained in this thread were in a sticky , issues that have come to light, (Serial number groups affected with Fan issues , noise on ch1 , ch2) , the best methods found either to fix or return
Most would say that the information on this CRO held with in this thread is valuable to anyone looking to purchase this CRO combined with the Youtube released videos
Cheers
sheldon
Perth - Australia
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It took me a few days to pick through this thread.
I found it worth the time and effort.
My OWON arrived yesterday intact and fully functional.
I spent about $520 for the newest SDS7102V with battery and bag.
It was an EBAY purchase.
Maybe I'll post a review on youtube if I have some free time.
Regarding the OP posting an updated video....he got rid of his scope long ago.
That said, most of the issues he outlined in his early posts have been edited as data came back that OWON had indeed directly addressed them in FW and HW updates.
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Regarding the OP posting an updated video....he got rid of his scope long ago.
That said, most of the issues he outlined in his early posts have been edited as data came back that OWON had indeed directly addressed them in FW and HW updates.
Well... yes and no. Yes, I did get rid of my Owon, but no, they haven't addressed most of the features I felt were lacking or problems I had with the scope. Specifically:
1) A way to mark, search easily, or just jump through long wave records.
2) Coarse/fine adjust of volts/div.
3) Split-screen window for FFT or zoom.
4) A SCPI command set or just improved data-exporting ability.
5) Show all measurements at once real-time (updated continuously).
6) Equivalent time sampling.
7) Linear interpolation of points or just the ability to turn off sin(x)/x.
As I mentioned on page 42 of this thread, IMO the top 4 are the most important features missing, the bottom 3 not so much.
Other problems I had with the SDS7102 were hardware features that weren't what they were advertised as (listed in the manual). I noticed that in the latest manual for the device (Mar. 2012 edition V1.4.5) they are STILL labelling these features the same as always - which indicates that they either changed the hardware (which I doubt) or are continuing to mislabel them. I know they are aware of the discrepancies since I had direct communication with Owon about these things for a few weeks, and they basically agreed with me:
1) Trigger Output. The manual says "Output trig signal synchronously". Could be more accurately labelled "Output refresh rate of the LCD" or something like that. It is NOT a true trigger output, by any normal definition.
2) Optically isolated Pass/Fail output is NOT optically isolated.
Edit: Of course, in a recap, I would forget to mention the biggest problem I had with the Owon :D - the very slow waveform update rates. That has certainly not been fixed/changed in firmware. Still, all in all, I think the Owon is good value for money; although it would be a great value if they would have programmed a higher waveform update rate while using less sample memory. But if you absolutely need a reasonably cheap DSO right now - and you don't do much debugging of high-speed digital circuitry - than it might be your best choice.
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1) A way to mark, search easily, or just jump through long wave records.
2) Coarse/fine adjust of volts/div.
3) Split-screen window for FFT or zoom.
Thank you Marmad for all your reviews.
I am thinking of buying the SDS7102, but holding off !!
I agree with your wish list but would reorder to 1) Split-screen, 2) add Marks 3) fine adjust. These all seem to be Firmware updates.
The question is, If I buy the SDS7102, do I have any hope that a new Firmware will be released by Owon?? It could be an update for all SDS models 6102, 7102 --> 9302.? Realistically, my guess is, only if $$$ are there! RF-loop. any rumours of firmware update? It is good to see 3 EBay sellers (same address) still have a sale on for 7102 LAN, VGA & Battery :).
Thanks again Marmad , RF-Loop and everyone for a good night school lesson in DSO's
PS the difference between Men and Boys are the Price of their Toys
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The question is, If I buy the SDS7102, do I have any hope that a new Firmware will be released by Owon?? It could be an update for all SDS models 6102, 7102 --> 9302.? Realistically, my guess is, only if $$$ are there! RF-loop. any rumours of firmware update? It is good to see 3 EBay sellers (same address) still have a sale on for 7102 LAN, VGA & Battery :).
Yes there is hope.
Owon have updated FW several times for fixing some critical bugs.
(zoomed) FFT cursors wrong frequency repaired some version ago.
Scan mode samplerate repaired/improved totally.
User can give file names when save, added some version ago.
Not exactly measured but feels like display/waveform handling have littlebit develobed faster.
(I can not proof becouse I have not old version for compare and before with old version I did not this measurement well enough)
Priority have been for make more and more stable software than hurry hurry add features without care about stability and then and drift into a deep spiral of more and new problems with a one point correction generates new problems. Owon has managed the errors of a serious and professional manner by ensuring that the priorities even if the pressure is also complementary to the properties. Fortunately, they have kept a cool head in this, although a too hasty change at some point did without proper justification. (Change in TFT backlight control).
Here is Owon official internet side. (http://www.owon.com.hk/index-en.asp) February 2012 they move official sides to hk, and soon they also open public download service for FW updates.
There is not any mind to update frequently with short time interval. But sooner or later there come some updates. What they include - this we can see later. But I hope most high priority they keep for stability and reliability in first place. What you do, do it well.. Quantity does not replace quality. Reliability, accuracy, stability, after sales customer care ... there is base key to go forvard. It is only road to real reputable name. There is no room for any big mistake.
My message to Owon: Do NOT hurry develop new features just becouse peoples push pressure. Stay calm. Do first reliability, accuracy, stability etc... repair carefully bugs in good order in priority. Test well before publish any update.
(We have seen too much these "oops" updates from some other brands.)
With good priority list and well argumented do some developing to UI ergonomy and some features to FW.
Just, do less but better, do simple but good.
Of course every peoples have more or less wish list...real useful,.. useful... nice to have and so on...
Maybe something like Fine adjust V/div
More features to cursors. (also level and time tracking) and becouse knobs have free push button... please use it as it is possible to make UI more handy.
Now there is "snap shot once" all measurements just like in old Tektronix. Please make it so that there is selection for repeate mode if user want select "repeat" mode for this. Of course user then accept update rate go slow but user select... )
Time mark... even just some and posibilty to fast jump using button betwen these.
Slow and fast mode for horizontal position knob.
Posibility to highlight real sampled point or shut off sinx/x
Posibility to change trace colors. (in some cases this red is not good over black bacround, specially if use single dots, so it is nice if example it can change example to green if user want.
Force whole capture to exactly screen area in run mode.
oh and wishlist is not in priority order and it may be long.
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Small test with Hantek and Owon.
I want capture video signal so that oscilloscope display one whole field.
Then I want stop capture (and last field is as single shot capture in memory for more detailed look and measurements.
Signal is normal one PAL video test signal where is "gray scale" (signal is color of course).
Oscilloscopes setting.
BW limit on (becouse all is under 20MHz)
Horizontal 2ms/div
100mV/div (Amplitude adjusted for around <8div (p-p <0.8V)
Memory 1M
Display dots.
1 channel in use. (becouse if two channel, Hantek drops to 500k memory and 10MSa/s and this can not accept for video)
Trigger: Video, Field (even and odd)
Video: PAL
First and most amazing was:
Waveforms per second.
Owon SDS7102V (unmodified V2.5.1) 16.6wfms/s
Hantek DSO5102B (unmodified HW1005 (e8) FW 120423) 1.2 - 1.3 wfms/s (measured only counting with eyes using watch)!
Hantek 20MSa/s
if Hantek set for two channel then memory is 512k for each channel and samplerate drops to 10MSa/s and update rate go agen littlebit more slow
In one channel mode it can stop and zoom so that every detail is just measurable in single video line. But just barely. In two channel mode there can not do measurements becouse undersampling.
Owon 25MSa/s
if Owon set for two channel then still memory is 1M per channel and samplerate do not change, still 25MSa/s (of course)
and update rate not markable difference. In single and two channel mode inside one video line there can do just barely all measurements but littlebit better than Hantek (due to samplerate difference and littlebit less noises)
But what happend if turn Owon to next step.
Other settings same. But memory 10M and becouse no affect there can also use two channel and it do not affect to update rate markable and it do not affect at all to samplerate what is 250MSa/s for both channels. (2ms/div speed)
Now whole field to display (2ms/div)
Update rate around 7 wfms/s
Stop and zoom in to one video line details.
It can extremely good quality look every detail in one single line and example measure color burst very accurate,
And it can use two channels so that there can be example same video signal from different points on the display.
With Hantek there come also one other problem. All buttons and adjustments works very slow!
It is so slow that there is some difficult to do adjustments and settings.
In same situation Owon buttons and adjustments works just as always.
In this individual special but practical situation Owon can do work just fine specially if want also 2 channel...
Hantek is with one channel just barely borderline to fail this work but it can do just barely.
If need two channel. Hantek drops totally and fails in this work. It can not at all.
Owon do it very nice and accurate and can easy go to all detail with acceptable fidelity laos for serius use.
PAL 4.43MHz color burst timing, level etc was piece of bisquit and all level and timing details can measure accurate.
Originally this whole video test come from one people who want find cheap scope what also can do this (single shot one whole field and then measure all details from single video line, and he ask if I can do real tests.
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In Owon synchronization with a video signal is implemented in hardware (there are two BA7046, one per channel).
https://www.eevblog.com/forum/general-chat/hantek-tekway-dso-hack-get-200mhz-bw-for-free/60/ (http://Here) I didn't found any HW on Hantek for extracting sync signals from a video signal. Thus may it be that Hantek uses a software synchronization? If so, 1.2-1.3 wfms/s is not a bad result :D
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here an update with my Owon scope's problems
bad stuck on green pixel :
i got update from my ebay seller and also from Owon's service, 1 bad pixel is NORMAL thing and is not a defect...
my seller said i need a bunch of them to be considered has a defect...
so people be aware of that you may end up with a bunch of them :o
bad probe:
for my probe defect, they said they will ship me a replacement ...
voidptr, did you check the vga output to see if the green pixel is there? Also, your photo seems like it is more than 1 pixel stuck on green. Can you take a clearer photo? it looks like 4 or more pixels are stuck on green, but that could be because of the low resolution photo. Do you have another photo?
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here an update with my Owon scope's problems
bad stuck on green pixel :
i got update from my ebay seller and also from Owon's service, 1 bad pixel is NORMAL thing and is not a defect...
my seller said i need a bunch of them to be considered has a defect...
so people be aware of that you may end up with a bunch of them :o
bad probe:
for my probe defect, they said they will ship me a replacement ...
voidptr, did you check the vga output to see if the green pixel is there? Also, your photo seems like it is more than 1 pixel stuck on green. Can you take a clearer photo? it looks like 4 or more pixels are stuck on green, but that could be because of the low resolution photo. Do you have another photo?
voidptr:
In picture it seems that hot green pixel is also in main area of display.
Innolux A grade accept maximum 3 dark (dead) pixel out from main area.
Independent of your seller opinion, take good pictures, one where just whole dislpay is visible so that it can see pixel position then some picture more close so that it clearly can see of there is single pixel or cluster. Also take one screen from scope to USB so that it can see pixel is not there (it is not but it is good to proof and even better if you chek it also with external SVGA monitor.
Send these pictures to Owon service (use these email address you find Owon HK sides.)
My opinion is that it is not acceptable on A grade TFT that there is stuck on pixel and specially in the main area of display.
In mainstream Owon opinion is over dealer opinion! So, ask Owon.
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In Owon synchronization with a video signal is implemented in hardware (there are two BA7046, one per channel).
https://www.eevblog.com/forum/general-chat/hantek-tekway-dso-hack-get-200mhz-bw-for-free/60/ (http://Here) I didn't found any HW on Hantek for extracting sync signals from a video signal. Thus may it be that Hantek uses a software synchronization? If so, 1.2-1.3 wfms/s is not a bad result :D
It can see that Hantek sync to standard video signal is sometimes difficult to sync.
Owon sync feels lot of more reliable.
But this waveform update rate is not related to only video.
100kHz square wave 1Vp-p
scope 2us/div
1 channel use (becouse Hantek can not 1M with two channels and I want both scopes have same settings for compare apples to apples)
1M memory selection (Hantek have in real 800k but it is hantek math. 800 = 1M)
display dots
normal acquire
Hantek DSO5102B (1005 e8, FW120423) around 2 waveform/sec Calculated with watch and counting from screen with eye.
Owon SDS7102V (1203 and 2.5.1) around 35 waveform/sec Measured using Owon "trig" (1) out signal with other oscilloscope.
Owon with 10M memory, all others same. Around 25 waveform/s
From 1k to 1M (with this speed) it is around 35.
Hantek is totally different if use 4k short memory.
In this, and only this, it is lot of faster. There come more waveform updates than screen updates In this case it beats Owon very clearly. Around five to ten times faster (max).
example 5ns/div (1k - 10M memory) one channel use Owon have around 40 waveforms/s
and same with 2 channel use, around 32.
39 (+-0.5) waveforms seems some kind of maximum. (measured with other oscilloscope using trig out interval measurement) (hantek DPO like update rate have discussed in other thread)
Hantek is fast ONLY with 4k memory.
With other settings and 40k memory it is still ok and not bad.
But with 500k and 1M settings it is really slow if look waveforms updating speed.
I have no idea what happend there.
(1) it is not real trig out as we can find example in Tektronix professional analog oscilloscopes.
But it is enough to calculate update rate becouse Owon is series prosessing conventional DSO.
Of course then if use measurements, persistence, menu open, etc.. they slow scope. Also Hantek.
But Owon do not never go to this speed what can clearly calculate with watch and counting with eyes.
(Of course if horizontal speed is limiting then of course. Everyone know if 100ms/div and there are 20 divs in full capture it takes 2 second + dead time. It is same for Rohde&Schwartz RTO and cheapest toy scope.
It is also good to rememeber what means "up to" or maximum as peoples read manufacturers ads.
Measured truth is not always same as image what we may imagine after reading ads.
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But this waveform update rate is not related to only video.
Really? I'm fairly sure this has all been discussed here before - but:
Owon SDS7102V (1203 and 2.5.1) around 35 waveform/sec Measured using Owon "trig" (1) out signal with other oscilloscope.
Owon with 10M memory, all others same. Around 25 waveform/s
From 1k to 1M (with this speed) it is around 35.
Either Owon has rewritten their firmware drastically since I had the scope - which seems unlikely - or this is incorrect. It is not only higher than what I measured - it is higher than what Owon themselves told me in emails that their waveform update rates were. So I'm not sure I can believe your figures, but regardless, these are STILL slow rates at LOW memory settings.
Hantek is totally different if use 4k short memory.
In this, and only this, it is lot of faster. There come more waveform updates than screen updates In this case it beats Owon very clearly. Around five to ten times faster (max).
Yes, again, in case you missed it, THIS IS THE POINT! The Owon does a 'reasonable' amount of wfrm/s if using deep memory - but it SUCKS at low memory settings - which makes it a major pain in the ass when trying to track down intermittant glitches. I did numerous tests with the Owon vs the Hantek in this regard, and on average, the Owon was 10x slower (which equates to HOURS of time) when looking for glitches. The Owon is NOT a good scope for debugging high-speed digital circuitry.
I see now that I need to go back and re-edit my original post in this thread to accurately reflect my final conclusions about the Owon SDS7102, because this thread is getting to be a mess. What I will say is basically this:
1) The Owon's hardware is very good. It appears to be both well-designed and built - and you get good value for money: large screen, battery option, decent front-end and good ADC/sampling engine.
2) The Owon's firmware sucks. There is no other way to put it. The only good thing you can say about it is that it is stable. In every other respect, from screen font, to color choices, to interface design, to features included, to usage of the nice hardware, to implementation of sampling/waveform updates - it is poorly done. It's a pity that they couldn't hire a team that was any good (like the hardware team) to write it. I could, without doubt, write better firmware myself.
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Yes, again, in case you missed it, THIS IS THE POINT! The Owon does a 'reasonable' amount of wfrm/s if using deep memory - but it SUCKS at low memory settings - which makes it a major pain in the ass when trying to track down intermittant glitches. I did numerous tests with the Owon vs the Hantek in this regard, and on average, the Owon was 10x slower (which equates to HOURS of time) when looking for glitches. The Owon is NOT a good scope for debugging high-speed digital circuitry.
No, I have not missed this at all. This I have also told in last message so that there clearly read Hantek is lot of faster when use 4k memory. Also everyone know what 4k memory do for samplerate as go for lower horizontal speeds.
In this clitch hunting Hantek beats Owon just 10-1. But nearly only in this. And then, if really need clitch hunting with serious work. I'm not sure Hantek is right tool. But yes, it can do it some low level and in this Owon is out. Owon IS conventional series processing DSO and in this it is quite good. It have not any parallel processing capability but Hantek have, littlebit.
Well, if I tell Owon waveform rate and you do not believe it is not my problem.
I have measured it and opponent is good and proof I'm wrong. As long as someone show I'm wrong I stay behind my data what I have measured. With settings I have told I have measured Owon trig out signal period and measured period was 25.35ms. Measurement done with well calibrated Tektronix 2465ADM
Other measurements with Hantek.
(Menu off except if other info)
4us/div 40k mem 1Ch
signal 500kHz
waves/s 33
500k memory
waves 6
1M memory
waves 3.5
4k memory
waves 255 and with menu ON around 280
change horiz speed
200ns/div
4k mem
waves 150
20ns
waves 190
8ns
waves 135
4ns
waves 135
And just as before Owon:
example 5ns/div (1k - 10M memory) one channel use Owon have around 40 waveforms/s
and same with 2 channel use, around 32.
Maximum what I find was around 280 but lck of time I did not go all posible settings combinations.
Maximum what I have find from Owon is around 40.
And it is good to note that Owon keeps well its speed from 1k to 10M memory.
But this Hantek max is available only with narrow scale of settings and only with 4k and then it good to note also what it mean in samplerates.
40k Hantek is not at all so fast.
100k - 10M it loose totally. In samplerate and in waveforms update rate.
with and only 4k Hantek is around 4 - 7 times faster in waveforms update rate or something like this.
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Well, if I tell Owon waveform rate and you do not believe it is not my problem.
Of course not - and it's not my problem if you say something different than Owon. I can only judge by my long email exchange with Owon, in which I asked the following:
"With Trigger Out, I always see output in the range of ~1 – 25Hz only, which would tend to indicate 1 – 25 waveform updates per second – or a ‘blind’ time, for example, at 200ns/div, of 99.99%.
Can you please let me know if I am incorrect and the waveform update rate for the Owon SDS7102 is faster than this?"
Owon responded:
"The waveform updated rate you mention is correct, unlike DS1052E (LCD display is 320*234), ours is 800*600 pixels, so there is more work for DSO to handle with, which result in updated rate is lower."
Of course, perhaps the hardware has been significantly changed or the firmware has been heavily rewritten in the last 8 months, but... hmm.. seems to me that they have other things which are more important than getting the wfrm/s rate pushed up from 25 to a whopping 35.
In this clitch hunting Hantek beats Owon just 10-1. But nearly only in this. And then, if really need clitch hunting with serious work. I'm not sure Hantek is right tool. But yes, it can do it some low level and in this Owon is out. Owon IS conventional series processing DSO and in this it is quite good. It have not any parallel processing capability but Hantek have, littlebit.
I never said that Hantek is necessarily the best tool either - I only made the comparison because YOU did first in your post - after I said the Owon's wfrm/s update rates were slow in my message from the previous page.
Rf-loop, seriously though... dude, this is getting kind of silly. Every time I come back on this thread (which I started to review a scope I bought) to mention some of what I believe to be the negative aspects of the Owon, you feel compelled to come back and argue against me (about a scope you sell).
Now I know that since I did the three YouTube video reviews of this scope, I have helped Owon sell hundreds (if not thousands) of units, but with all due respect, this is kind of annoying here. Perhaps you need to start your own thread where you sing the praises of Owon and their scopes?
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Maybe you have missed this other test (page 38-39)
This is directly from TFT surface, not from "trig" out. And also this give same kind of result.
With two totally different methods... from trig out and from visible TFT surface so that they are real displayed captures.
If some one in Owon answer to you he/she just did not know about what you are talking or did not know or you talked just different things. So, maybe it is better first test and measure and then give opinions. Measured real data and these my tests are repeatable where ever and what time ever as long as devices under tst are same. This is displayed waveforms update rate in real life.
But, if talk about "trig" out... due to delay related to real trig point... my opinion is that it is not usefully useable even 1/25s.
Also, waveform update rate drops some amount if using menu, connect dots etc.
Here repeated this one test pic. (and yes, with same method I have tested also with Hantek)
And about Owon - Hantek. Both oscilloscopes I have argumented many ways to good in this price class. If Owon is good or bad. Only truth is important to me, and just same for Hantek or example Rigol.
In professional work use and hobby use, I use Tektronix, Agilent and R&S equipments and recommend them for serious use (nearly) without exeption.
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If Owon is good or bad. Only truth is important to me, and just same for Hantek or example Rigol.
Sorry, but MANY of the things you've posted in this thread are NOT the 'truth' - they are your own subjective opinion (what features are important to have, how well or quickly Owon is handling firmware updates, etc, etc, etc) - I could make a long list. And opinion becomes even less objective - and less trustworthy - when there is a financial arrangement involved. Since you seem to disagree with most of the conclusions I've come to regarding my Review of Owon SDS7102 (this thread) - I suggest you do your own review and thread - which would better reflect your 'truths'.
Honestly, I'm finding more and more co-opting of the reviews of the Owon I did by people with a financial interest at stake (e.g. websites selling the Owon with my videos embedded; people involved financially with the company 'debating' in this thread, etc) and I'm getting rather tired of it. I have half a mind to blow up this thread very soon.
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Sorry but real measurements give real data.
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Sorry but real measurements give real data.
I already stated that 25 or 35 wfrm/s is irrelevant to me; either one is too slow with 1k (or even 10k) memory depth - imo, it just highlights poor firmware design. But we're clearly not talking about the same thing anymore - that seems to have ended a few posts ago.
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marmad,
Why did you make your SDS7102 reviews on youtube private? ???
That reminds me of the school kid who takes his ball home when things dont go his way.:)
P
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Why did you make your SDS7102 reviews on youtube private? ???
If you've been reading this thread then you might have an idea from my previous posts, but to clarify:
1) This thread has become rather a mess - partially because of the way it developed during the making of the 3 parts of my video review (and my own shifting feelings about the scope) - and partially for other reasons mentioned earlier. This is evidenced by a comment you yourself made 5 days ago that was incorrect:
That said, most of the issues he outlined in his early posts have been edited as data came back that OWON had indeed directly addressed them in FW and HW updates.
2) As mentioned previously, my videos (the early, most positive ones) have been found embedded in commercial sites selling the Owon. As you might imagine, I didn't make the videos as advertisements for people with financial interests at stake.
3) Lastly, I get a fair amount of PMs and emails from people who are a bit confused and looking for a more definitive answer about scope recommendations.
So, I'm trying to figure out the best way to consolidate my final thoughts/reviews in one place - and to try to suppress the usage of my efforts as commercial advertisements. To do this, I think I need to re-edit the 3 small videos into 1 or 2 longer pieces - so I made them private temporarily - but they will be made public again later.
That reminds me of the school kid who takes his ball home when things dont go his way.:)
Hmm... I'm not sure I understand your analogy. This isn't a game; I spent my own time and energy creating and posting the videos and review threads to help other prospective buyers. Whatever I want to do with my videos - including moving them, re-editing them, deleting them, etc - is my own prerogative - just as it will be yours if you spend some of your own time doing the same.
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I've replaced the board but had faced with another issue: there ia a large interferences caused by backlight LED DC-DC converter. Earlier on old board I've discovered some weak interference from backlight (https://www.eevblog.com/forum/product-reviews-photos-and-discussion/review-of-owon-sds7102/645/ (https://www.eevblog.com/forum/product-reviews-photos-and-discussion/review-of-owon-sds7102/645/)), but it disappeared when I connected a 50 Ohm BNC terminator or probe, even when I connected a 10kOhm resistor or any signal source with any output impedance there was no interference, so it did not affected measurements because it was visible only when nothing is connected to inputs.
I've compared peak level of noise of my oscilloscope with screenshots which other people shared on the Internet and found it is about the same. Thus I've considered that it is OK, now I have reasons to gues that it is not OK :(.
With new mainboard interference is much larger and they are enlarged when I connect terminator to input. I've installed the old mainboard again and see the same very small interference visible only on open input. Thus it is not due to incorrect installation - because I swapped boards few times and always I get negligible interference with old board and large interference with the new one.
The problem appears when powered from battery or from AC mains. So it is definitelly not a PSU problem.
I've made screenshots with new boards. X10 probe configuration is selected for both channels. I just forgot to switch it to X1, thus V/Div readings on the screen should be divided by 10 to get the actual input sensitivity.
An interference on both channels is the same. I leave CH1 open (no probe connected) and connect 50 Ohm BNC terminator to CH2 to show that 50 Ohm terminator increases an interference.
NewBoard_1.png: CH1 is open, CH2 shorted to ground through 50 Ohm BNC terminator, brightness is 0%.
There RF noise extremely low for 2mV/Div sensitivity. Seems that it is even much lower than a noise on the old board.
But there is a terrible 30kHz interference from backlight LED driver.
NewBoard_2.png: CH1 is open, CH2 shorted to ground through 50 Ohm BNC terminator, brightness is 100%.
30kHz noise is much lower comparing to an interference with 0% brightness, but it is still present and spikes occasionally appears.
NewBoard_3.png: FFT for CH2 which is shorted to ground through 50 Ohm BNC terminator, brightness is 0%.
30kHz interference with harmonics is clearly visible.
NewBoard_4A.png, NewBoard_4B.png: Even with low sensitivity 30kHz interference is clearly visible. With 2V/Div interference is higher than with 1V/Div. Thus interference comes rather through power line than through input.
It doesnt look like a mainboard issue, because there are a lot of DC-DC converters on the adapter board and on the mainboard itself and only an LCD backlight step-up causes interference. I guess that a mainboard of new revision is just more sensetive to low-frequency ripple on supply voltages rails and a real problem is a LCD backlight step-up on the adapter board or new mainboard has some compatibility issues with old adapter board (I'm not sure that OWON changed adapter board, this is only an assumption). There are a lot of changes in analog and power management parts on the new board comparing to my old one.
Thus I would like to ask people who have SDS7102 - have you any signs of 30kHz noise with visible low display brightness with open input (no probes connected)?
Because I have this noise on two mainboards of different revisions - on old 1209*** it is wery weak and produces no visible impact on measurements, but it is still visible when nothing is connected to input BNC, especially on FFT. On new board (1211****) interference level raises when I connect a probe. I've recorded a video, you can see that on 2V/Div with an input is connected to probe compansation output an interference just makes any precission measurements impossible (while on 1V/Div it is much lower):
MVI_3023_Interference.mkv (https://www.youtube.com/watch?v=thldpvawsAw#)
And the second strange thing - I've noted some strange behavior of external synchronization input when it is configured to trigger on falling signal edge, on old mainboard the trigger works fine, so owners of 1211**** devices, please check check is this issue appears on your devices. On the video both ext trigger input and a channel input are connected to probe compensation output and an AC coupling is selected for trigger and channel input itself:
MVI 3025 Trigger (https://www.youtube.com/watch?v=02iTe5TiX0A#)
Resolved by adding an inductor on 5.4V rail as it was proposed by OWON.
-
ZAP
Contact seller (if seller is ok with Owon they can negotiate it with Owon, it must not be end user problem if reseller is real ok) or directly Owon hk service and tell failed TFT.
my seller told me i need at least 3 dead stuck on pixels to be considered a bad lcd, so else i will pay for exchange and there is no warranty i will get one without bad pixel ...
so i think i can live with it, until i have enough money to buy a scope from a better company...
8)
here an update with my Owon scope's problems
bad stuck on green pixel :
i got update from my ebay seller and also from Owon's service, 1 bad pixel is NORMAL thing and is not a defect...
my seller said i need a bunch of them to be considered has a defect...
so people be aware of that you may end up with a bunch of them :o
bad probe:
for my probe defect, they said they will ship me a replacement ...
Owon is reputable company.
If your reseller is just lazy or loosy it is not so nice.
If there is stuck on pixel in main area of display it is fail!
For resolve this, take GOOD picture where is whole display so that it can easy detect pixel position on the TFT and show exatly its position..
Then also take more close picture to show better this pixel.
Stuck on pixels are NOT accepted on the main area of display.
Remember tat "bad pixel" can not understand. Example dead dark pixel is totally different case and also it is "bad pixel". Pixel or sub pixel what is always bright on is classified much more bad and also it is "bad pixel" but there need make big difference between different fails and where is fail position on the display area. Of course one sub pixel is not so severe than cluster of pixels but... bright always on pixel in main area, not accepted at all in industrial A grade TFT.
Owon use Innolux A grade display and it need meet this! If not, it is warranty issue = fail and it need repair.
(Also it is not fail what happend later in warranty period, it have been failed as it was new and arrive to you? )
Send pictures directly to Owon. Address you find Owon hk official side.
After then you can tell to whole world how Owon in real life handle this fail so that no one can think Owon is some chinese crap company. They have good after sales customer care and they want really handle rare warranty fails as reputable companies do. It may littlebit also understand chinese cultural differencies for succesfull hadling problems.
If you have communication problem with Owon, please ask some help so that can do successful negotiation with Chinese company.
Owon want be, and they are, real reputable company who really care also quality and they will care customers also after get just money. This they want be and this they need also show - I know they want. I believe they want rise they brand from dark where they was before years after they launch they first model 6-7 years ago.
All do mistakes, all brand can be warranty fails, but who repair mistakes and care about this there are real differencies. There can separate reputable companies and crap companies.
If your display do not meet quality class it is fail and it need repair.
First people who there answer to your email maybe do not have enough power or knowledge for solve your situation or classify this problem or he/she maybe did not understand what you are talking and what is exactly problem.
-aghp
-
Hi,
I just received my SDS7102 today from ebay seller. I am measuring my circuit shown in picture 1 (ch1 on pin 10, ch 2 on pin 11) which is a 12v inverter(this circuit works properly before I get OSC). I am measuring by press "Autoset" button, the result is shown in picture 2(osc_1.png) why not picture 3(osc_2.png).
Sorry for my bad English.
Bob
-
Maybe you have alt trigger mode on. Change it to Ch1 mode.
-
Trigger is in ALT mode or CH2 is inverted.
Just first, set factory default. (in utility menu)
Then use autoset.
- if you do not want learn how to adjust manually oscilloscope for good settings.
If tsill result is same, really look that trigger source is CH1 (or CH2)
(btw, if you have selected ALT trig mode and selected trigger frequency to display you get 2 frequency window on the right bottom corner.
Autoset do not always give best result (and important, it do not touch all settings. What settings it affect is described user's manual (Mar 2012 edition 1.4.5) side 73.
(autoset is ok but sometimes with more complex signals it is very good to learn how oscillocope work and how to setup it manually. Specially it is important to know if you have changed some settings what autoset do not touch! And how they affect)
-
Hi, EV and rf-loop
Thank you very much for your comments
Maybe you have alt trigger mode on. Change it to Ch1 mode.
Before I use Autoset I set my OSC shown in the picture 1(snap1.gif) an trigger source is CH 1.
When I press Autoset button it automatically changed to ALT mode but if I only use CH 1(CH 2 disconnected) , it's not change from Single mode to ALT mode.
Trigger is in ALT mode or CH2 is inverted.
Just first, set factory default. (in utility menu)
Then use autoset.
- if you do not want learn how to adjust manually oscilloscope for good settings.
If tsill result is same, really look that trigger source is CH1 (or CH2)
(btw, if you have selected ALT trig mode and selected trigger frequency to display you get 2 frequency window on the right bottom corner.
Autoset do not always give best result (and important, it do not touch all settings. What settings it affect is described user's manual (Mar 2012 edition 1.4.5) side 73.
(autoset is ok but sometimes with more complex signals it is very good to learn how oscillocope work and how to setup it manually. Specially it is important to know if you have changed some settings what autoset do not touch! And how they affect)
I set trigger to Single but it changed to ALT mode as I mentioned above.
CH 2 is not inverted and CH 1 is trigger source.
In the manual Mar 2012 Edition 1.4.5 Page 73, the Trigger Type is current means no change? but it's changed.
http://owon.com.hk/down-en.asp?bigclassname=%CB%B5%C3%F7%CA%E9%CF%C2%D4%D8 (http://owon.com.hk/down-en.asp?bigclassname=%CB%B5%C3%F7%CA%E9%CF%C2%D4%D8)
Actually, I know how to manually adjust oscilloscope without Autoset button , but I just want to test my SDS7102 for first time.
OWON SDS7012 Autoset issue (https://www.youtube.com/watch?v=chVAJH-ynY4#)
-
Hi, EV and rf-loop
Thank you very much for your comments
Maybe you have alt trigger mode on. Change it to Ch1 mode.
Before I use Autoset I set my OSC shown in the picture 1(snap1.gif) an trigger source is CH 1.
When I press Autoset button it automatically changed to ALT mode but if I only use CH 1(CH 2 disconnected) , it's not change from Single mode to ALT mode. Or better if they cancel change.
Trigger is in ALT mode or CH2 is inverted.
Just first, set factory default. (in utility menu)
Then use autoset.
- if you do not want learn how to adjust manually oscilloscope for good settings.
If tsill result is same, really look that trigger source is CH1 (or CH2)
(btw, if you have selected ALT trig mode and selected trigger frequency to display you get 2 frequency window on the right bottom corner.
Autoset do not always give best result (and important, it do not touch all settings. What settings it affect is described user's manual (Mar 2012 edition 1.4.5) side 73.
(autoset is ok but sometimes with more complex signals it is very good to learn how oscillocope work and how to setup it manually. Specially it is important to know if you have changed some settings what autoset do not touch! And how they affect)
I set trigger to Single but it changed to ALT mode as I mentioned above.
CH 2 is not inverted and CH 1 is trigger source.
In the manual Mar 2012 Edition 1.4.5 Page 73, the Trigger Type is current means no change? but it's changed.
http://owon.com.hk/down-en.asp?bigclassname=%CB%B5%C3%F7%CA%E9%CF%C2%D4%D8 (http://owon.com.hk/down-en.asp?bigclassname=%CB%B5%C3%F7%CA%E9%CF%C2%D4%D8)
Actually, I know how to manually adjust oscilloscope without Autoset button , but I just want to test my SDS7102 for first time.
Oscilloscope features change first and then later they update manual after they collect group of changes.
In this case it looks like this manual version have obsolete information. Mar 2012, of course it is old and obsolete. ;)
My opinion is that autoset must not force it to ALT mode! (Why they have changed it.)
Becouse more frequantly need CH1 and 2 signal have time sync. There are many scopes what do not have ALT trig mode at all.
We need wait agen new updated manual. ;)
Or better if they cancel this change so that this manual text is right.
It is better to do more important developments!
-
try autosetup with exact the same signal on both channels (e.g. Q to both channels), just to double check that this is default
autosetup issue or just one created by asynch signals (where alt trigger make sense).
-
try autosetup with exact the same signal on both channels (e.g. Q to both channels), just to double check that this is default
autosetup issue or just one created by asynch signals (where alt trigger make sense).
Hi, tinhead
I tested as your recommendation. The result is same.
If this change occurred by design , I think it is very mistake.
-
try autosetup with exact the same signal on both channels (e.g. Q to both channels), just to double check that this is default
autosetup issue or just one created by asynch signals (where alt trigger make sense).
If this change occurred by design , I think it is very mistake.
Personally also I do not like this. I like if it do not touch ALT, if user selected it, it kep it, if not, it do not turn it on.
On the other hand if someone connect two, not sychronized signals to oscilloscope inputs and push autoset. What happend if it do not touch to autoset. Then he ask why autoset do not work. Name is autoset but it works only partially.
This is always problem. One case people like orange but sometimes he like bicycle more and sometimes orange is better.
But personally and also becouse it is terrible difficult to really regognize if ALT is better than other setting, it is better that autosetup do not touch this. It is better that user know how to use oscilloscope and what he is really doing.
How much autoset need do? What is need never do, what it need always do, what it need try if do not find settings. How fast autosetup need be.
This is my opinion that it must not change trigger mode. But it need regognize if there is only one signal and select only it to display (close unused channel) and select used channel to trig source. But then, if there is some other trigger settings than facory defaults allready by user. How much these settings autosetup need change?
But becouse it is extremely difficult to know if really need ALT, it is better to do simply. If there is one signal, it is clear what to do. If there is two signal, protocol is best be so that it try find CH1 settings and trig and adjust CH2 level so that peak levels do not overshoot.
But in final game, there is not exactly one right way. It is only collection about different opinions if look all possible situations and all waht autoset need do and what not. Possible "right" combinations for autoset protocol is "lot of".
As long as this work like this here explained and if really "need" autoset, just connect CH1 and push autoset.
Turn then CH2 on and select this known V/div for CH2.
What if user have forget to ALT mode... do it need cancel it? It can also think that oscilloscope may have several users.
My first wish to Owon is that default is not behind menu. It need be directly front panel HW.
But there is so many different needs and opinions.
After bowing to the east - looks back on the west.
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@rf_loop
@aghp
thanks for your comments :-)
so here what happen since my last message,
fast resume:
when i received my scope i found i have 1 always stuck on bad pixel.
i also had a bad noisy probe.
my ebay seller, said to me he will send my 2 new probes, i got them Monday after trying then i also found i have another one busted...
so i just retake better pictures and a video of my test on probes.
----
bad pixel
(http://i1114.photobucket.com/albums/k539/n45w73/dev%20stuff/IMG_0011.jpg)
(http://i1114.photobucket.com/albums/k539/n45w73/dev%20stuff/IMG_0009.jpg)
-----
bad probes
http://s1114.photobucket.com/albums/k539/n45w73/dev%20stuff/?action=view¤t=badprobes2of4.mp4 (http://s1114.photobucket.com/albums/k539/n45w73/dev%20stuff/?action=view¤t=badprobes2of4.mp4)
i started with the 2 bads probes,
the first (the new bad on i got Monday) seems to be grounded, i start at 1v and connect it to square wave calibration,
and i had to go to 20mV to see a distorded signal, of course it cant be calibrated...
sometime when you move it around noise appear but not has bad noise as the second probe
the second bad one shows buzz noise when i got to 20mV
then i switched to the 2 goods one ...
showing both correct 5v square wave ...
and they are not showing any noise when i move the wire around ...
so 2 bads probes of 4 ....
---------------------
SO ...
i just resent a new message to service@owon.com.cn
telling them my concern and wondering about the quality of their product.
i also just resent a message to my ebay seller with the same concern ...
so i will wait and see what happening ...
i have so much other stuff to do than deal with that kind of problems ...
:-\ :-\ :-\
-
One bad pixel? ???
Not meaning to sound rude, but I am curious why you are even wasting you time trying to chase that down? :)
.....and you have two good probes now.
What more do you expect?
A new replacement scope? If so, just come out and tell the vendor so, and pack it all back up for a refund. Why drag it out?
-
One bad pixel? ???
Not meaning to sound rude, but I am curious why you are even wasting you time trying to chase that down? :)
Well, bad pixels on an oscilloscope screen equate to bad data - whenever a waveform crosses near the pixel, it will appear as if the bad pixel(s) are part of the waveform. Granted one pixel isn't much, but the screens are so damn tiny on these scopes to begin with - and, let's face it, the devices are kind of expensive compared to similar non-measurement equipment - I think I'd want to see if I could get an exchange myself.
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Well, bad pixels on an oscilloscope screen equate to bad data
Nonsense.
99% of plots are waveforms (scope connects the dots), not x/y plots. Not only will the dot not be a part of the waveform, but it will have no value in the "data" of the digital waveform
I think I'd want to see if I could get an exchange myself.
Exactly! That is my point. Why beat around the bush about it with post-after-post, documenting with very detailed pictures of the perpetrator-dot. Get a new scope and be done with it.
-
Back on topic.
When I run an FFT, the frequency reading (using cursors) on the scope is off.
However, the frequency of the same waveform is spot-on when viewed using the PC software.
This is not random. It happens everytime.
Scope is new with LAN/VGA hardware (got it 2 weeks ago), version 2.6
Test#1 setup and data:
Input is CH1, or CH2....it matters not....both behave same.
My test signal is a 27.25MHZ sine-wave (XTAL-controlled),
I take a 10db reading at 5MHZ, giving sample resolution is about .025Mhz (50mhz/2040)
On the scope, the frequency reads 27.44 (using cursors) at leftmost part of screen.
Move the 27.25MHZ point to the center of screen, frequency now reads 27.30.
Move it to far right, frequency reads 27.30.
When I download the same waveform to the PC software, ALL readings (27.24mhz) are spot-on to within a single sample resolution of .025MHZ.
The scope-interpreted readings can be as much as 10(!) samples off!
Test#2
The same thing happens with a 72.9MHZ signal, but it is more pronounced.
Any ideas?
PS: this single thread is the best OWEN SDS hardware/software discussion on the net!....even with all that green-pixel talk!
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Nonsense.
99% of plots are waveforms (scope connects the dots), not x/y plots. Not only will the dot not be a part of the waveform, but it will have no value in the "data" of the digital waveform
I understand that the bad pixels have no value in the actual digital data - but the displayed waveform (the pixels illuminated on the LCD) is the 'data' which you retrieve with your eyes when measuring signals. As I mentioned before, 1 pixel is not a big deal - but I might be worried that more pixels close by would go bad. What if you had 5 bad pixels forming a short line? When part of the waveform being measured intersected or touched that line, and you looked over at the screen, you would see a waveform (the 'data') that was partially incorrect - with an extra segment integrated into it.
This seems an obvious point - you get most of your 'data' from the scope by looking at the screen. If the screen starts going bad - it interferes with getting good data just as a bad probe would.
-
A new software bug?
It is happened(random) when I use Autoset button and CH 2 floated, CH 1 connected to circuit.
owon SDS7102V trigger name issue (https://www.youtube.com/watch?v=9AakvGxTZms#)
-
A new software bug?
It is happened when I use Autoset button and CH 2 floated, CH 1 connected to circuit.
owon SDS7102V trigger name issue (https://www.youtube.com/watch?v=9AakvGxTZms#)
CH2 floated and picked up something as signal and you press autosetup. You try to some kids play or just fun?
How this oscilloscope can know if CH2 signal what it see is real what you want look or if signal is just something from some floating wire? With oscilloscope perspective this is signal and autosetup try find "guess" what it is and try find settings for this signal.
"autosetup" other function is: "Lets look if you (oscilloscope) are more clever than me."
You can also try to connect some antenna to both inputs and try if autosetup can guess what is going on.
Try this. take old analog "museum" TV set and 4 meter wire. Connect other end of wire to oscilloscope input and other end only two turn over TV without any connection to TV. Or something other same fun.
Maybe it is time to get first some real experience and skills with test equipments and after then look if equipment work wrong or if it is more clever than user... (do not take seriously) ;)
With old HP digital I can enable or disable what parameters autosetup can change and what it keep untouched.
Becouse Owon have not this feature it is difficult in some cases as it try scan all posibilities using some priority order.
After soon I will test also. Then I can maybe give real and more serious answer.
;)
Personally I did not like they change it so that autosetup also change some trigger selection.
Some want, some do not want. What is ok for one people is not ok for other.
-
Well, I own an SDS8102 for more than half a year now, so I might add some comments
here.
Firstly, I like the size, the silent fan, the 10M record length. The (electrical)
noise level seems to be pretty good for its class. Though some buttons feel a bit
cheap, I'm kinda happy with the hardware side.
I can live with the slow wfs/s, the missing windowed zoom (though I still miss it)
and the crappy PC GUI.
What lowers its value for me is the bad implementation of several features,
especially the automatic/manual measurement.
1) The automatic measurements are inaccurate as hell and therefore kinda useless.
With 500MS/s or even 1GS/s, a 100µs period is displayed as 100.000µs as is an period
of 100.12µs
When the period gets a bit larger, the period jumps to 0.100ms.
With 500MS/s, measurements down to 10ns should be easily possible, so this is
either a buggy or bad implementation.
2) Even worse, accurate manual measurement is also not possible. While you
could measure with the cursors, the problem is that both cursors must be visible
at the same time. If you zoom in or out, the cursors remain at their screen
position, not at the sample where you put them.
And if you try to measure completely manually by subtracting cursor positions
related to the trigger point, this also fails as the cursor positions are
displayed as 0.XXXms for anything larger than 100µs.
So all in all, it's impossible to measure with a better accuracy than 1µs in
a 100µs period.
3) There is no kind of statistics for measurements (min/max/mean/standard deviation)
4) There is no gating implemented for measurements.
Indeed you can't even see which period was measured as nothing is marked. You just
get one value displayed and can't trust it, because you don't know where it was
measured. Even if there is only one possible position, the measurement is still
inaccurate (#1).
5) Simple measurements as number of pulses/edges between cursors are missing.
There are other things that are weird or a little annoying
1) "Save / Wave" saving only one channel and "Copy" button not using the last
setting (e.g. Image). Also
2) You can't e.g. change the record length when the scope is stopped.
3) The trigger level cursor is always pink and doesn't use the channel's color
4) In cursor mode, the vertical knobs change the cursor positions, but pushing
the buttons still resets the vertical position, not the cursor position.
5) Edge triggering on "both" edges is not possible
6) Changing from "Normal" to "Auto" trigger mode is clumsy (3 key presses):
Trigger Menu -> Single&Holdoff -> Auto/Normal
There should be a button on every scope, but if not, it must be at least in the
fist menu level as you need it all the time.
All in all, it's a shame to see that the SDS scopes are so much limited by their
software. And as Owon managed to implement only a few bugfixes and even
fewer marginal improvements in over one year, I kinda lost hope that the SDS
line will ever reach a level where they really live up to their expectations.
Honestly, what's the point in having 1GSa/s and a 10MPts memory if you still
can't measure anything below 1µs accurately in a 10µs/div setting?
-
Well, I own an SDS8102 for more than half a year now, so I might add some comments
here.
Firstly, I like the size, the silent fan, the 10M record length. The (electrical)
noise level seems to be pretty good for its class. Though some buttons feel a bit
cheap, I'm kinda happy with the hardware side.
I can live with the slow wfs/s, the missing windowed zoom (though I still miss it)
and the crappy PC GUI.
What lowers its value for me is the bad implementation of several features,
especially the automatic/manual measurement.
1) The automatic measurements are inaccurate as hell and therefore kinda useless.
With 500MS/s or even 1GS/s, a 100µs period is displayed as 100.000µs as is an period
of 100.12µs
When the period gets a bit larger, the period jumps to 0.100ms.
With 500MS/s, measurements down to 10ns should be easily possible, so this is
either a buggy or bad implementation.
2) Even worse, accurate manual measurement is also not possible. While you
could measure with the cursors, the problem is that both cursors must be visible
at the same time. If you zoom in or out, the cursors remain at their screen
position, not at the sample where you put them.
And if you try to measure completely manually by subtracting cursor positions
related to the trigger point, this also fails as the cursor positions are
displayed as 0.XXXms for anything larger than 100µs.
So all in all, it's impossible to measure with a better accuracy than 1µs in
a 100µs period.
3) There is no kind of statistics for measurements (min/max/mean/standard deviation)
4) There is no gating implemented for measurements.
Indeed you can't even see which period was measured as nothing is marked. You just
get one value displayed and can't trust it, because you don't know where it was
measured. Even if there is only one possible position, the measurement is still
inaccurate (#1).
5) Simple measurements as number of pulses/edges between cursors are missing.
There are other things that are weird or a little annoying
1) "Save / Wave" saving only one channel and "Copy" button not using the last
setting (e.g. Image). Also
2) You can't e.g. change the record length when the scope is stopped.
3) The trigger level cursor is always pink and doesn't use the channel's color
4) In cursor mode, the vertical knobs change the cursor positions, but pushing
the buttons still resets the vertical position, not the cursor position.
5) Edge triggering on "both" edges is not possible
6) Changing from "Normal" to "Auto" trigger mode is clumsy (3 key presses):
Trigger Menu -> Single&Holdoff -> Auto/Normal
There should be a button on every scope, but if not, it must be at least in the
fist menu level as you need it all the time.
All in all, it's a shame to see that the SDS scopes are so much limited by their
software. And as Owon managed to implement only a few bugfixes and even
fewer marginal improvements in over one year, I kinda lost hope that the SDS
line will ever reach a level where they really live up to their expectations.
Honestly, what's the point in having 1GSa/s and a 10MPts memory if you still
Maybe there is many errors or just simple, SDS7102 is better.
Only two examples.
a)
"3) The trigger level cursor is always pink and doesn't use the channel's color"
No, trigger level cursors are yellow to CH2 and red to CH1.
Cursors are for measurement using human eye so it also follow DISPLAY resolution, not sampling resolution.
b)
"can't measure anything below 1µs accurately in a 10µs/div setting?"
Cursors "step" resolution on the display in this case is 0.2us. and this becouse 1div is 50 pixel
How human can use cursor measurement more fine than display resolution.
Accuracy is related also to sampling timebase.
I just test.
Signal 50 000 000 Hz +- 0.01Hz
Oscilloscope warmed, and >half hour on.
Mem 10M
CH1
10us/div.
Single capture.
Zoom in to 2ns/div.
As accurate as human eye with 8x magnifier can with cursors so that can really check it is just righ in pixel level sure..
Cursors delta 20.00ns
(cursors moving resolution now of course 0.4ns (becouse 50pix/div)
captured with 10us/diV and measured better than 1ns real accuracy in this case.
Then I run scope 2ns/div with same signal. Result exatly same.
Ok, with 2ns/div automatic measurement show Period 20.00ns
Freq 50.00MHz, Cycle RMS 15.25mV (signal generator 15.9mV)
Of course there is now termination resistance error and oscilloscope BW flatness error. (signal is 50MHz and so littlebit attenuated).
Then just for fun.
Tektronix scope calibrator CG5001
1kHz
1V/div x8
Owon (CH1 DC, 10k mem, 100us/div):
Period 1.000ms, duty 50%
Peak-peak 8.080V
Vamp 7.920
With cursors
Period 1.000ms
Level 7.96V (Adjusted for best match possible with cursors resolution (0.04V)
It is good to remember that ADC vertical resolution is 8 bit. (not real accuracy)
Then scope calibrator to 10kHz
measure period.
With cursors there read 100.000us.
10div or less with this setting cursors reading step is 0.2us.
Over 10div cursor step continue 1pixel on display BUT reading step change to 1us.
But, honestly I can not see any kind of accuracy problem but just opposite. Owon is amazing accurate in this price class. (But I do not like it change cursors reading resolution if cursors delta is more than 10div on the display.)
In what oscilloscope you can measure with cursors more accurate and with more resolution what is display itself?
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Well, I almost guessed that it doesn't use the sample memory, but the display buffer for measurement, but this is crap of course. I'm aware that even Agilent scopes in the higher price range do it the same way, but that's one reason more to dislike them.
At least the better LeCroy scopes (WaveSurfer/WaveRunner) always measure in the sample memory though. It's a mystery to me why anybody could assume that measuring in the display buffer was acceptable. IMHO this makes measurements more or less senseless, as it's more guessing than measuring.
Anyway, with any other DSO I ever worked with (even those CRT based Agilents, LeCroys and Tektronix from the late eighties), it was possible to move the cursors inside the sample buffers without the need to always show both of them. So it was always at least possible to do accurate manual measurements by setting the cursors in a zoomed view. As this isn't possible with the SDS scopes either, they make it impossible for me to do exact measurements.
All in all, the 10Mpts sampling buffer (letting aside that using 2GSa/s cripples it to 10k) is still nice to have, but its potential is not used at all. There is no convenient zoom feature, no way to search for data in the sample memory, no way to do (accurate) measurements in the sampled data.
Honestly, I'm toying with the idea of selling it an buying something else which is more usable...
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@0xdeadbeef - Yes, I think most of us agree that the Owon has fine hardware and build quality - especially for it's price class. But unfortunately, it's been encumbered with crap firmware - on many levels.
There is the minor level - which is just annoyance. Such as not being able to change screen colors, fonts, design errors in the user interface, etc.
There is the medium level - which goes beyond annoyance - to slowing down your work due to missing or badly implemented features. In this category I would include lack of tools to mark and search easily in large records, the crappy PC GUI (and lack of SCPI commands, etc), some of what you mentioned, etc.
Lastly, there is the high level - where the firmware actually gets in the way of the quality of the data you can capture with the scope. This is also some of what you mentioned in your post, no fine control in vertical adjust, a clumsily-written sampling routine (which appears to work always the same, regardless of record depth), etc.
But it IS stable :D
As of now, I think of the Owon as a good cheap learning/teaching scope - especially with the VGA and LAN outputs, but while I DO like the Owon hardware, the delivered firmware just seemed too much of a compromise for me when spending >$500 for something.
So I opted to return it while I could get a full refund and wait - either for them to revamp their firmware to take advantage of their nice hardware (which they don't appear to be doing - at least not anytime soon) - or else for a new scope which would fit my needs better - even if costing more.
Well, the Rigol DS2072 is almost here - and though it costs twice as much as the Owon - from what I've read, it seems way more than 2x better. No battery or VGA - but those features were always just 'bonus' ones for me anyway - not things I really needed. But we'll have to see what it's like when it arrives.
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Sorry to hear, I've been following this saga since your initial posts almost 1 year ago. In the end, a scope can be ergonomic and feature rich, but affecting its measuring fidelity is, IMHO, a fatal flaw. That's foremost what you want a scope to do. Since first appearing in ~ 2009??, the Rigol 1052e has not faltered seriously in its basic measuring capacity, and many folks on eevblog have been pushing it to its limits.
...But it IS stable :D
As of now, I think of the Owon as a good cheap learning/teaching scope - especially with the VGA and LAN outputs, but while I DO like the Owon hardware, the delivered firmware just seemed too much of a compromise for me when spending >$500 for something.
So I opted to return it while I could get a full refund and wait - either for them to revamp their firmware to take advantage of their nice hardware (which they don't appear to be doing - at least not anytime soon) - or else for a new scope which would fit my needs better - even if costing more.
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Sorry guys I do not understand everything you said bu for the summary
Do I get it or not ?
If not , I can not get good ones like Tektronix , so do you have other options for me ?
I can not spend more than 500 $ because the shipping to my place will cost me to much (each lb = 9$) .
marmad
As you are returning it , I think I should not get it , am I wrong ?
When do you think you are reposting your review ?
Thanks
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Hi guys, I have tried to read some of this thread but it is long and am not sure what is the most recent info. I want to buy a new scope, and was thinking of the OWON SDS7102 or the Hantek dso5202b - for example. Any advice would be welcomed.
Or maybe there are other, better scopes in the price range I could go for?
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Hey guys, sorry - I've been travelling but am now settled down with some free time - and can hopefully finish updating this thread and re-posting my video review this week.
SH@RK & akis: I returned the Owon quite awhile ago - and was waiting either for Owon to significantly update their firmware - or for a better 'bang for the buck' scope to appear. I'm still waiting - and in the meantime, I have an 'oscilloscope piggy-bank' - where I throw spare change - so that I can afford (without seeming to spend more money) to jump to a higher-tier of scope.
What scope is best for you depends on a lot of factors - not just the price. Are you a hobbyist, semi-professional, or professional? What do/would you use the scope for most of the time: general purpose, audio work, high-speed digital circuitry, etc? Are there particular features which are critical for you: screen size, PC control and communication, battery-operation, etc?
I might still own the Rigol DS1052E if it had a larger screen (and a quieter fan would be good - though you can fix that yourself if desired). I might still own the Owon if it had either better firmware tools for large record lengths - or a faster waveform update rate with small record lengths. I might still own the Hantek if it had either better PC c/c or less buggy firmware. Each scope has attributes and faults which have to be balanced against your needs.
I will post a more thorough comparison and suggestion guide later this week, but in the meantime - in short - my opinion is this:
You are a hobbyist/semi-professional AND you do mainly audio work: you need Bode plotting for filter construction/debugging - consider the Velleman PCSGU250 - a great USB scope bargain (and the only with built-in Bode plots) at around € 130 in the EU.
You are a hobbyist/semi-professional AND glitch-hunting/debugging high-speed digital circuitry is NOT your primary scope use: you need deep memory OR battery-operation OR VGA output (for teaching or presentation)- AND PC ctrl/comm. is NOT important - get the Owon.
You are a hobbyist/semi-professional: you want large screen OR hackability - AND PC ctrl/comm via standardized SCPI commands is NOT important - get the Hantek.
You are a hobbyist/semi-professional: you need cheapest price OR PC ctrl/comm via SCPI - AND screen size is NOT important - get the Rigol.
You are semi-professional/professional: you need large screen AND fast update rates AND PC ctrl/comm - save some money and get something that costs 2 - 2.5x more - but is 5 - 10x better.
Edit: BTW, by hobbyist, semi-professional, and professional - I strictly mean (in this context) that you will make zero/a bit of/a reasonable amount of/ money from the use of the oscilloscope.
...but that said the update rate for most of the ranges beats the hantek, the hantek is appalling most of the time
Dave.S: What data are you basing your statements on? Did you have both scopes and run side-by-side measurements? Or did you just own the Hantek for awhile before the Owon? My own impressions, after having both scopes, was that the Hantek was significantly faster with 1k record lengths on many ranges.
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Yes but only on 1K.
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While this again is a bit offtopic, I recently investigated into scopes in the 1k€-3k€ price range. And I'm kinda depressed right now, since all of them lack at least one of the features that I's like to have.
Stuff like measuring in the sample data (only for Hameg and LeCroy I'm really sure that they use the sample data), statistics (Tektronix DPO2000 simply has none, others have strange implementations), gating for measurements (no Agilent scope seems to have sensible gating as they obviously think the zoom window would be good enough, the Hamegs only support a kind of gating for semi-manual measurements), counting pulses/edges (surprisingly the Rigol DS4000 seems to miss this point completely). Also basic features are surprisingly badly designed. E.g. as the Owon, the Agilent DSX3000 has no button to switch between auto/normal trigger mode though this is something that you need all the time.
Generally, I'm underwhelmed by the displayed precision for cursor positions and measurements. With 1GSa/s and above, it should be somehow possible to measure if a pulse is 100µs or 100.01µs. That's 10ns and with 1GSa/s 10 points in the sample data. Still, scopes in the <8k€ range seem to cripple their measurements by either measuring in the display data or at least showing only three or four digits. The best result you can expect is something like 100.0µs, which reduces the accuracy to 100ns. Better than nothing you could say, but still not enough for certain purposes and I still think that a 1GSa/s scope should allow you to measure a period down to the sample period (1ns), even if there will be a certain jitter of course.
Then again, the SDS lacks all of these features. It's nice for observing the shape of waveforms and you can do rough measurements with it, but for precise measurements, it's completely useless. I'm not convinced though, that any other scope in this price range is really much better in this regard.
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While this again is a bit offtopic, I recently investigated into scopes in the 1k€-3k€ price range. And I'm kinda depressed right now, since all of them lack at least one of the features that I's like to have.
I think that DSO prices in general are rather depressing. They certainly seem overpriced compared to other electronic goods - and while you can argue that they are 'test equipment' and about development costs - to me it seems to have at least as much to do with history and captive market as anything else: the analog scopes cost X amount - and since these are similar (or better) in capabilities (though cheaper in terms of manufacture, materials and calibration), they should still cost X amount too.
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Yeah well, measurement equipment is a small market compared to consumer electronics - and low quantity usually means high prices. Also the problem is of course that mainly companies buy scopes and e.g. 10k€ is not really much money for a company. That's about what an external engineer costs per month. That also explains the crazy prices for addons, plugins etc.
E.g. an SPI decoder for a LeCroy 6Zi costs around 1k€ (excluding VAT). That's simply insane for something so simple considering that measuring periods is already implemented. Then again, for a company that's petty cash. As a side note: surprisingly, Rigol seems to be the 2nd most expensive company regarding addons. They sell I2C, SPI and UART separately where each protocol costs as much as a 2-protocol bundle from Agilent or Tektronix. Let's see if they offer better prices for the DS2000 line at least.
Anyway, I still hope that the prices will come down eventually - also regarding arbitrary generators. But currently it doesn't really look like it. There is nearly no competition amongst dealers either. The prices of all the brand scopes I observe are rock stable, close to no current DSO is sold on eBay and if so, people pay nearly the full price...
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OOPSOOPSOOPS
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While this again is a bit offtopic, I recently investigated into scopes in the 1k€-3k€ price range. And I'm kinda depressed right now, since all of them lack at least one of the features that I's like to have.
Stuff like measuring in the sample data (only for Hameg and LeCroy I'm really sure that they use the sample data), statistics (Tektronix DPO2000 simply has none, others have strange implementations), gating for measurements (no Agilent scope seems to have sensible gating as they obviously think the zoom window would be good enough, the Hamegs only support a kind of gating for semi-manual measurements), counting pulses/edges (surprisingly the Rigol DS4000 seems to miss this point completely). Also basic features are surprisingly badly designed. E.g. as the Owon, the Agilent DSX3000 has no button to switch between auto/normal trigger mode though this is something that you need all the time.
Generally, I'm underwhelmed by the displayed precision for cursor positions and measurements. With 1GSa/s and above, it should be somehow possible to measure if a pulse is 100µs or 100.01µs. That's 10ns and with 1GSa/s 10 points in the sample data. Still, scopes in the <8k€ range seem to cripple their measurements by either measuring in the display data or at least showing only three or four digits. The best result you can expect is something like 100.0µs, which reduces the accuracy to 100ns. Better than nothing you could say, but still not enough for certain purposes and I still think that a 1GSa/s scope should allow you to measure a period down to the sample period (1ns), even if there will be a certain jitter of course.
Then again, the SDS lacks all of these features. It's nice for observing the shape of waveforms and you can do rough measurements with it, but for precise measurements, it's completely useless. I'm not convinced though, that any other scope in this price range is really much better in this regard.
I am very, very new to the idea of digital scopes and sampling used for displaying a trace but:
Some rough calcs : with 1 billion samples per second rate, I'd want say 20 samples per period to be able to show a decent curve, and that would mean a max input frequency of 50 MHz. If the curve is more complex I'd want even more samples per period meaning less max frequency capability. In that respect if the scope is being sold as a two channel 50 MHz scope I'd think it's about right. At 100MHz that would leave 10 samples per period on one trace and 5 samples per period for dual trace. Can you really show a trace with 5 or 10 samples over its period? I leave that to the experts to answer :)
Then it is also the sampling depth , or whatever else we call this : "bits per sample" - that means if the screen has 8 vertical divisions, how many bits do we allocate per division? I'd hope we would allocate at least 3 bits per division (0 to 7, ie seven distinct levels within each verticule) making this 3 * 8 = 24 bits per sample. Modern VGA cards work at 32 bits per pixel and at GHz levels so I do not see a problem here. But something tells me that all these digital scopes do not have 24 bit sampling depth - am I right?
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While this again is a bit offtopic, I recently investigated into scopes in the 1k€-3k€ price range. And I'm kinda depressed right now, since all of them lack at least one of the features that I's like to have.
Stuff like measuring in the sample data (only for Hameg and LeCroy I'm really sure that they use the sample data), statistics (Tektronix DPO2000 simply has none, others have strange implementations), gating for measurements (no Agilent scope seems to have sensible gating as they obviously think the zoom window would be good enough, the Hamegs only support a kind of gating for semi-manual measurements), counting pulses/edges (surprisingly the Rigol DS4000 seems to miss this point completely). Also basic features are surprisingly badly designed. E.g. as the Owon, the Agilent DSX3000 has no button to switch between auto/normal trigger mode though this is something that you need all the time.
Generally, I'm underwhelmed by the displayed precision for cursor positions and measurements. With 1GSa/s and above, it should be somehow possible to measure if a pulse is 100µs or 100.01µs. That's 10ns and with 1GSa/s 10 points in the sample data. Still, scopes in the <8k€ range seem to cripple their measurements by either measuring in the display data or at least showing only three or four digits. The best result you can expect is something like 100.0µs, which reduces the accuracy to 100ns. Better than nothing you could say, but still not enough for certain purposes and I still think that a 1GSa/s scope should allow you to measure a period down to the sample period (1ns), even if there will be a certain jitter of course.
Then again, the SDS lacks all of these features. It's nice for observing the shape of waveforms and you can do rough measurements with it, but for precise measurements, it's completely useless. I'm not convinced though, that any other scope in this price range is really much better in this regard.
I am very, very new to the idea of digital scopes and sampling used for displaying a trace but:
Some rough calcs : with 1 billion samples per second rate, I'd want say 20 samples per period to be able to show a decent curve, and that would mean a max input frequency of 50 MHz. If the curve is more complex I'd want even more samples per period meaning less max frequency capability. In that respect if the scope is being sold as a two channel 50 MHz scope I'd think it's about right. At 100MHz that would leave 10 samples per period on one trace and 5 samples per period for dual trace. Can you really show a trace with 5 or 10 samples over its period? I leave that to the experts to answer :)
Then it is also the sampling depth , or whatever else we call this : "bits per sample" - that means if the screen has 8 vertical divisions, how many bits do we allocate per division? I'd hope we would allocate at least 3 bits per division (0 to 7, ie seven distinct levels within each verticule) making this 3 * 8 = 24 bits per sample. Modern VGA cards work at 32 bits per pixel and at GHz levels so I do not see a problem here. But something tells me that all these digital scopes do not have 24 bit sampling depth - am I right?
Yep. Modern VGA cards working at 32bits @ 1680x1050 as i'm typing away ... i'm not too sure if they run at GHz levels OR not , at least i know the pixel clock on mine is at 550MHz but i agree it's GHz levels because of the 2.2 Gigapixels/sec pixel fill rate ( It's a Mobility HD 5430 anyway )
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I REALLY wish there was competition , i mean like okay 1Gigsamples ... What's the speed of a standard ADC converter in a off the shelf notebook you find now?
They have 24 bits 5gigsamples ADC's in there.
Really? Please elaborate on where I can find such a notebook and why it would need such a powerful chip.
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I REALLY wish there was competition , i mean like okay 1Gigsamples ... What's the speed of a standard ADC converter in a off the shelf notebook you find now?
They have 24 bits 5gigsamples ADC's in there.
Where? The only analog input signals that come to mind are audio and wifi, and neither has anywhere near 5Gb/s bandwidth.
AND quad-core 1.4GHz 35W chips ... i mean what's stopping agilent to make cheaper stuff ? They have HP by their side and a fab of their own ( they make the megazoom asics so i assume they have a fab of theirs )
As was already answered by 0xdeadbeef, scale. Look at the number of CPU's Intel sells compared to the number of scopes Agilent sells. I can't be bothered to do the research now, but I expect many orders of magnitude difference.
I think that DSO prices in general are rather depressing. They certainly seem overpriced compared to other electronic goods - and while you can argue that they are 'test equipment' and about development costs - to me it seems to have at least as much to do with history and captive market as anything else: the analog scopes cost X amount - and since these are similar (or better) in capabilities (though cheaper in terms of manufacture, materials and calibration), they should still cost X amount too.
Analog scopes were much more expensive in their heydays. In 1959, the 30 MHz Tektronix 545A cost $1550 without the essential plug-in amplifiers, about $12,000 in 2011 money. In 1977, a 100 MHz Tektronix 465 cost $2145, which would be something like $8000 in 2011 money. In 1993, when DSOs were already available, the 100 MHz Tektronix 2245A (cheaper construction, less parts) cost $2595, about $4000 in 2011 money.
Yep. Modern VGA cards working at 32bits @ 1680x1050 as i'm typing away ... i'm not too sure if they run at GHz levels OR not , at least i know the pixel clock on mine is at 550MHz but i agree it's GHz levels because of the 2.2 Gigapixels/sec pixel fill rate ( It's a Mobility HD 5430 anyway )
You're confusing a lot of specs. The pixel clock of a 1680x1050 VGA signal is most likely something like 150 MHz, and is produced by a DAC, not an ADC. Of those 32-bits per pixel, 8 bits are alpha channel and never transmitted to the monitor, and the other 24 bits are split across three different colors. Also note that VGA connectors on computers are usually outputs, not inputs. Unless you have a fairly old monitor, chances are that you're using a digital (DVI/HDMI/DisplayPort) connection, which does not involve any ADC/DAC. 550 MHz is most likely the clock rate of the (digital) GPU. 2.2 Gigapixels (texels?) / sec refers to the number of pixels the GPU/graphics memory can process per second.
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Some rough calcs : with 1 billion samples per second rate, I'd want say 20 samples per period to be able to show a decent curve, and that would mean a max input frequency of 50 MHz. If the curve is more complex I'd want even more samples per period meaning less max frequency capability. In that respect if the scope is being sold as a two channel 50 MHz scope I'd think it's about right. At 100MHz that would leave 10 samples per period on one trace and 5 samples per period for dual trace. Can you really show a trace with 5 or 10 samples over its period? I leave that to the experts to answer :)
I'm not sure if or how this could relate to my posting. Does it at all? If not, why quoting it?
Anyway, to reconstruct a sine, you need a sample rate that's at least twice the sine frequency (Shannon and friends). 10 samples per period are not that much, so a non-sinewave might look a bit ugly depending on the reconstruction algorithm applied, but that this shoudln't influence period measurement. I was talking about measuring a 100µs pulse period +/-10ns. So in the sample buffer there are ten more values with the same high voltage level and even if the automatic measurement fails and the displayed edge looks a bit SINCinsh, I want to be able to set the cursors at the samples that I consider to be the edges and get an accurate delta time displayed (sample_number/sample_frequency) with a good precision.
A decent scope can do this and I don't see why implementing this should be difficult.
Then it is also the sampling depth , or whatever else we call this : "bits per sample" - that means if the screen has 8 vertical divisions, how many bits do we allocate per division? I'd hope we would allocate at least 3 bits per division (0 to 7, ie seven distinct levels within each verticule) making this 3 * 8 = 24 bits per sample. Modern VGA cards work at 32 bits per pixel and at GHz levels so I do not see a problem here. But something tells me that all these digital scopes do not have 24 bit sampling depth - am I right?
Now you lost me completely. Even scopes in the multi k€ price range only have an 8bit sample resolution (and "hires" modes are usually nothing but oversampling). But this has absolutely nothing to do with the screen resolution or the display bandwidth or whatever. Honestly, I don't see your point at all.
Anyway, when implemented correctly, the display resolution (letting aside the bandwidth) has nothing to do with measurement accuracy. Again, with a decent scope, I can set both cursors in a maximum zoom mode on the exact sample and get the correct distance between those two cursors, no matter what the current zoom level is. As said before: measuring in the display data is a design flaw and I don't get why e.g. Agilent engineers and customers see this differently.
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I REALLY wish there was competition , i mean like okay 1Gigsamples ... What's the speed of a standard ADC converter in a off the shelf notebook you find now?
They have 24 bits 5gigsamples ADC's in there.
Where? The only analog input signals that come to mind are audio and wifi, and neither has anywhere near 5Gb/s bandwidth.
AND quad-core 1.4GHz 35W chips ... i mean what's stopping agilent to make cheaper stuff ? They have HP by their side and a fab of their own ( they make the megazoom asics so i assume they have a fab of theirs )
As was already answered by 0xdeadbeef, scale. Look at the number of CPU's Intel sells compared to the number of scopes Agilent sells. I can't be bothered to do the research now, but I expect many orders of magnitude difference.
I think that DSO prices in general are rather depressing. They certainly seem overpriced compared to other electronic goods - and while you can argue that they are 'test equipment' and about development costs - to me it seems to have at least as much to do with history and captive market as anything else: the analog scopes cost X amount - and since these are similar (or better) in capabilities (though cheaper in terms of manufacture, materials and calibration), they should still cost X amount too.
Analog scopes were much more expensive in their heydays. In 1959, the 30 MHz Tektronix 545A cost $1550 without the essential plug-in amplifiers, about $12,000 in 2011 money. In 1977, a 100 MHz Tektronix 465 cost $2145, which would be something like $8000 in 2011 money. In 1993, when DSOs were already available, the 100 MHz Tektronix 2245A (cheaper construction, less parts) cost $2595, about $4000 in 2011 money.
Yep. Modern VGA cards working at 32bits @ 1680x1050 as i'm typing away ... i'm not too sure if they run at GHz levels OR not , at least i know the pixel clock on mine is at 550MHz but i agree it's GHz levels because of the 2.2 Gigapixels/sec pixel fill rate ( It's a Mobility HD 5430 anyway )
You're confusing a lot of specs. The pixel clock of a 1680x1050 VGA signal is most likely something like 150 MHz, and is produced by a DAC, not an ADC. Of those 32-bits per pixel, 8 bits are alpha channel and never transmitted to the monitor, and the other 24 bits are split across three different colors. Also note that VGA connectors on computers are usually outputs, not inputs. Unless you have a fairly old monitor, chances are that you're using a digital (DVI/HDMI/DisplayPort) connection, which does not involve any ADC/DAC. 550 MHz is most likely the clock rate of the (digital) GPU. 2.2 Gigapixels (texels?) / sec refers to the number of pixels the GPU/graphics memory can process per second.
Oops, but yeah i am aware the actual speed is 150MHz, STILL faster then a low end scope though.
I correct whatever i said above, just ignore it. 2.2gigpixels is a different thing to texels it has like 8.8 Gigasamples/sec samples fill rate and 4.4gigtexels fill rate
ANYWAY, i do know 550MHz is the core clock, yes i know the stuff i work on as i design graphical display outputs
But still 32bits is 32bits
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no, i'm not protecting HanTekway in any case, they still have, let me think, 10+ bug for sure,
but let's compare a bit to Owon to see the MAJOR hadrwae difference (and this was already said multiple times here
and in Tekway thread).
Yes but only on 1K.
no, it's not like that, you have to understand the hardware first.
Generally I recommend www2.rohde-schwarz.com/file/1ER02_1e.pdf
HanTekway when sampling with 1GSs and 4k buffer is able to capture 2500wfrm/s (4us capture time).
These 2500wfrm/s are back calculated relative to 10DIV, which is in real live 2100 when 16DIV visible and
1900wfrm/s when 20DIV visible.
While capturing with 40k buffer the sample rate is 400MSs or 500MSs (which depends on hw model version),
when you take the latest model this give us 80us capture time.
The relation between active acquisition time and fixed(blind) time is not fixed to screen refresh rate (which is the case for Owon),
it is like on every other DSO an dynamic value. As long we do not change the setup (e.g. by adding an extra FFT measure or what
so ever affecting postprocessing - even timebase!) while sampling with different sample depth the ratio change proportional to active
acquisiton time. This mean when sampling witk 40k buffer and 500MSs you can assume that the 80us need to be divided by
known value 4us (from which we know its equal to 2500wfrm/s). This give us factor 20 ... now divide the 2500 by 20 and you
will get 125 wfrm/s per 10DIV (real live for full 20DIV screen 95 wfrm/s) which is the value for 20ns/DIV and 40k depth single channel.
When you do the same with 1Mpoint, this is 2ms capture time and 500 times slower than when with 4k, give us 5 wfrm/s
per 10DIV, real live worst case value is then 3.8wfrm/s. This seems to be what visually observed by others on these DSOs.
So what is wrong with Owon? Well, they decided to made the fixed (blind)time fixed to somewhat 25ms - no matter what memory
depth or sampling rate. When the depth is set to 1k the buffer will be of course postprocessed very fast (smallest capture time is 1us)
- but then the loop takes still 25ms - that's 39.99 wfrm/s. Now when you take 10Mpoint, that's 10ms capture time giving total loop
time of 35ms - that's 28.57 wfrm/s.
We might wonder where this 25ms is coming from. My guess: this is one thread system, therefore you need to have some kind
of fixed post-processing turn around on which then display buffer, sample buffer, i/o and all other systems are (relative) based.
The 25ms seems to be good value, that's 40 display buffers per second, or 40 x 10Mpoint (so 400M/s for buffer memory)
and for sure fast enought to capture i/o (this is why you don't see any front panel lag when in 10M in compare to 1k on Owon).
This calculation might be of course wrong, only Owon can answer it in detail, however for my hardware understaing it makes
sense why it works like that.
Based on that I agree with marmad, Owon need to change the "base" in the firmware to speed-up to wfrm/s rate. The sample buffer
when smaller than 10M need to be postprocessed multiple times per one cycle, but then we would have a DPO-like and not
DSO-like device. Sure there are other non-DPO-like devices on the market having higher wfrm/s rate than Owon, this is not
because they better implemented but only because they do have variable cycle time for data processing and fixed for display
which means the data will be shown asynch to acquisition (this could be a good implementation for Owon too).
However in such systems you need to have two "clocks", which is not the case in one thready Owon firmware.
As Owon never ever managed to develop such implementation (SDS is the latest hardware and it does have the same gaps
as older Owon models - they also based on Samsung SoC and one thread firmware) i doubt they will be able to fix it now.
However what they can do is to implement all other missing things, then only the wfrm/s would be worse than on competitor models,
and that would be already very good thing for all of us using Owon hardware.
You are a hobbyist/semi-professional: you want large screen OR hackability - AND PC ctrl/comm is NOT important - get the Hantek.
PC ctrl/comm is luckily not a dark hole anymore, we have all the information how to control these DSOs and how to
understand the data. There is already great custom PC software (for Mac/Linux/Win) allowing to remote control,
to export buffer to csv (few standards), to capture screenshots or ot capture data to PC screen, etc.
What missing if only FFT (on the to do) and access to raw data buffer (not on to do as still some company confidential information
unknown - but i'm working on that).
Check screenshots on
http://www.dreisiebner.at/dso-usb-tool/ (http://www.dreisiebner.at/dso-usb-tool/)
http://www.dreisiebner.at/dso-usb-tool/screenshots.htm (http://www.dreisiebner.at/dso-usb-tool/screenshots.htm)
Nevertheless LabView support is still missing, however it can be easily build based on the PC protocol
informations posted in here
http://elinux.org/Das_Oszi_Protocol (http://elinux.org/Das_Oszi_Protocol)
and here
http://www.mikrocontroller.net/articles/Hantek_Protokoll (http://www.mikrocontroller.net/articles/Hantek_Protokoll)
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Yep. Modern VGA cards working at 32bits @ 1680x1050 as i'm typing away ... i'm not too sure if they run at GHz levels OR not , at least i know the pixel clock on mine is at 550MHz but i agree it's GHz levels because of the 2.2 Gigapixels/sec pixel fill rate ( It's a Mobility HD 5430 anyway )
1680*1050*100Hz = 176.4Mhz with only 8-bit per channel.
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Then it is also the sampling depth , or whatever else we call this : "bits per sample" - that means if the screen has 8 vertical divisions, how many bits do we allocate per division? I'd hope we would allocate at least 3 bits per division (0 to 7, ie seven distinct levels within each verticule) making this 3 * 8 = 24 bits per sample.
You need 3+log2(8 ) = 6 bits per sample.
Modern VGA cards work at 32 bits per pixel and at GHz levels so I do not see a problem here. But something tells me that all these digital scopes do not have 24 bit sampling depth - am I right?
First of all, VGA cards have DAC's, but not ADC, thus it is not a legal comparison.
And, of course, there are 3 8-bit DAC's in a VGA card (one DAC per a color channel). 3 x 8-bit DAC is not the same as 1 x 24-bit DAC ;)
I REALLY wish there was competition , i mean like okay 1Gigsamples ... What's the speed of a standard ADC converter in a off the shelf notebook you find now?
They have 24 bits 5gigsamples ADC's in there.
24-bit @ 5GSPS ADC - it is just impossible. Moreover, notebooks have no fast ADC at all.
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PC ctrl/comm is luckily not a dark hole anymore, we have all the information how to control these DSOs and how to understand the data.
Tinhead, I did think about this when I wrote the previous comment - and the HanTekway has certainly passed the Owon in this regard now. It's just not as good/easy as the Rigol with it's standardized SCPI command set. But I went back and modified the post a bit to better reflect this distinction.
One thing I wanted to mention here in regards to the future of DSOs: USB 3.0. Many people (Dave included) have commented on the problems and limitations with USB scopes - and many of those were due to the bandwidth speeds of USB 2.0. But if you've used any USB 3.0 devices (like an external drive) you can see that it's a brave new world when it comes to communication speeds between the PC and external devices. Of course, USB scopes will never have the portablity of standalone DSOs - but, if you have a lab set up with work computers driving equipment like I do - that's not such a big issue. Try downloading the software for a PicoScope and running it with 4 different waveform windows running on a computer with a 1900x1200 screen - there ain't nothing like it in the standalone world for clarity, precision, and wealth of simultaneous information.
I believe a new collection of USB 3.0 scopes are on the horizon - and might very well make USB scopes, for many people, the bang-for-buck match of - if not the better deal than - standalone DSOs. Hopefully it will also help drive further down standalone DSO prices.
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I don't think USB 2.0 is what limits the current USB scopes. USB 3.0 is not fast enough for real-time sampling, so you still need the sampling memory. It's not like the refresh rate is what's limiting the current USB scopes. The problem is that nobody designed an affordable scopes with an analog frond-end that does not suck and ADC and memory depth competitive with the often similarly priced bench scopes. Things have gotten slightly better since Dave did the comparison, but it's still very hard, if not impossible, to find a USB scope competitive with the Rigol DS1102E (100 MHz BW, 1 GS/s sampling rate, 1 Mpoints memory, 2 channels, though not all specs at the same time) at a similar/lower price. The Picoscope 3200 series comes close, but costs something like $1000 for 100 MHz BW.
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I don't think USB 2.0 is what limits the current USB scopes. USB 3.0 is not fast enough for real-time sampling, so you still need the sampling memory.
You'll always need buffer memory - but memory is cheap, so what? And it depends what you think 'fast enough' is. USB 3.0 could support real-time sampling rates of 300 MS/s (8-bit) uncompressed - and with aggregation you could likely push it over 1 GS/s. Of course, it depends on clever design and good drivers and software.
The Picoscope 3200 series comes close, but costs something like $1000 for 100 MHz BW.
Yes, but to be fair, you should be comparing it to something like the Agilent DSOX2002A - and not the Rigol. Don't just look at it's sampling rate - look at it's collection of features, triggers, software, etc. It's miles above the Rigol in my opinion.
Anyway, there was a wave of USB scopes (and logic analyzers, etc) that came out after the dust settled on the 2.0 spec. - I believe the same thing will happen again with 3.0.
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You'll always need buffer memory - but memory is cheap, so what? And it depends what you think 'fast enough' is. USB 3.0 could support real-time sampling rates of 300 MS/s (8-bit) uncompressed - and with aggregation you could likely push it over 1 GS/s. Of course, it depends on clever design and good drivers and software.
We need to separate DRAM and SRAM. In SRAM each bit is a trigger which consists of several transistors, and in DRAM a bit is a single p-n junction. Therefore SRAM costs much more than DRAM.
But SRAM is easier to use for real-time sampling at high sample rate, therefore it is widely used in oscilloscopes.
Owon's SDS series is rather an exception - for sample rates up to 1GSPS they use cost-effective DDR2 DRAM which allows them to have 10MB of memory per channel.
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Has anyone so far got an opinion of which of these scopes comes with the best probes (I presume I mean smallest capacitance) / or with differential probes out of the box / or with the best ability to use the pseudo differential mode with two channels ?
I ask because I have been working with a "low" frequency device recently, 200 KHz, and am finding all sorts of things about my ageing scope and my probes that I had not thought of before.
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One bad pixel? ???
Not meaning to sound rude, but I am curious why you are even wasting you time trying to chase that down? :)
.....and you have two good probes now.
What more do you expect?
A new replacement scope? If so, just come out and tell the vendor so, and pack it all back up for a refund. Why drag it out?
ZAP Why beat around the bush about it with post-after-post, documenting with very detailed pictures of the perpetrator-dot. Get a new scope and be done with it.
dear pullin-gs,
i am so sorry you had to read my message :(
i really don't know why you took the time to respond to it tho if it wasn't good enough for you ! ::)
oh i see you might be "the best message content estimator of this site" ...
for others people :)
i repost cleaner pictures because i received 4 private messages asking about them.
it seems that at least some people care about that kind of silly problems...
i routinely buy lcd 1920x1200 without ANY bad pixel, and i don't see why they sent me 2 bads probes on 4, maybe quality management fail somewhere.
so end of story,
i gave neutral review with comments to my ebay seller (who is a member here i think)
i didn't get any response back to my 2nd message from Owon,
for now scope is ok for my need and i will buy something better when i will have more money.
:)
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One bad pixel? ???
Not meaning to sound rude, but I am curious why you are even wasting you time trying to chase that down? :)
.....and you have two good probes now.
What more do you expect?
A new replacement scope? If so, just come out and tell the vendor so, and pack it all back up for a refund. Why drag it out?
ZAP Why beat around the bush about it with post-after-post, documenting with very detailed pictures of the perpetrator-dot. Get a new scope and be done with it.
dear pullin-gs,
i am so sorry you had to read my message :(
i really don't know why you took the time to respond to it tho if it wasn't good enough for you ! ::)
oh i see you might be "the best message content estimator of this site" ...
for others people :)
i repost cleaner pictures because i received 4 private messages asking about them.
it seems that at least some people care about that kind of silly problems...
i routinely buy lcd 1920x1200 without ANY bad pixel, and i don't see why they sent me 2 bads probes on 4, maybe quality management fail somewhere.
so end of story,
i gave neutral review with comments to my ebay seller (who is a member here i think)
i didn't get any response back to my 2nd message from Owon,
for now scope is ok for my need and i will buy something better when i will have more money.
:)
I will certainly do the same and get this as my starter scope then get a DSOX3000 down the road
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You'll always need buffer memory - but memory is cheap, so what? And it depends what you think 'fast enough' is. USB 3.0 could support real-time sampling rates of 300 MS/s (8-bit) uncompressed - and with aggregation you could likely push it over 1 GS/s. Of course, it depends on clever design and good drivers and software.
It may be usable on lower sampling rate, just like the long memory option on Rigol scopes, but at that point you're saving the relatively cheap DRAM, not the expensive RAM that can run at full speed. Not sure how much BOM costs this saves, especially if you factor in the premium for USB 3.0 transceivers.
Yes, but to be fair, you should be comparing it to something like the Agilent DSOX2002A - and not the Rigol. Don't just look at it's sampling rate - look at it's collection of features, triggers, software, etc. It's miles above the Rigol in my opinion.
Sure, it has more features, though I'm not sure the Agilent is a fair comparison, since its banner spec is the fast update rate. My point was that this is the cheapest scope made by Picoscope (and I can't think of too many cheaper competitors) that exceeds the entry level scope which has been dominated by the Rigol DS1052E/1102E for the past five or so years. And you pay $600 extra for the lack of screen and controls.
Has anyone so far got an opinion of which of these scopes comes with the best probes (I presume I mean smallest capacitance) / or with differential probes out of the box / or with the best ability to use the pseudo differential mode with two channels ?
I ask because I have been working with a "low" frequency device recently, 200 KHz, and am finding all sorts of things about my ageing scope and my probes that I had not thought of before.
If you're talking about Owon/Hantek/Rigol, then I believe they're more or less the same: they all suck in this regard. None of them have invested significantly in probe development as far as I know. Rigol sells an active probe, but I don't think it works with the DS1000E series. There are some generic differential probes by companies like Testec, which will work with any scope. The big vendors: Agilent, Lecroy and Tektronix each have a huge number of probes, including low capacitance, current and active probes, but the active probes usually use proprietary power connectors, so you either have to use their scopes or provide a DIY solution (it's usually just some DC voltages). They also make the best passive probes, although you would probably be hard pressed to notice this at 200 kHz (assuming we're talking 200 kHz bandwidth). Don't be surprised to pay more than for an entry level scope for an active probe. Some of the Tek/HP/Agilent branded probes are occasionally available on eBay for slightly less outrages prices.
Poor-man's differential probes don't work well on any scopes (scopes with proper differential inputs like the analog Tek 7000 series with 7A13 amplifier excluded). The old Tektronix TDS-200 series had a spec of 100:1 CMRR at 60 Hz, down to 20:1 at 50 MHz. Modern scopes often don't even spec CMRR anymore, so don't expect it to be much better.
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It may be usable on lower sampling rate, just like the long memory option on Rigol scopes, but at that point you're saving the relatively cheap DRAM, not the expensive RAM that can run at full speed. Not sure how much BOM costs this saves, especially if you factor in the premium for USB 3.0 transceivers.
Well, it seems pointless to argue this. You don't seem to feel that USB 3.0 scopes will make any difference in the market - I disagree. We'll just have to wait and see.
Sure, it has more features, though I'm not sure the Agilent is a fair comparison, since its banner spec is the fast update rate. My point was that this is the cheapest scope made by Picoscope (and I can't think of too many cheaper competitors) that exceeds the entry level scope which has been dominated by the Rigol DS1052E/1102E for the past five or so years. And you pay $600 extra for the lack of screen and controls.
I'm not saying that USB scopes couldn't be priced lower (I think Velleman has made inroads in this direction), but I think you're a bit out of touch with the market. The Picoscope 2207 - which has the 100MHz bw and 1GS/s rate - plus a built-in AWG and function generator - lists for $740 on the Picoscope website.
Also, I don't personally feel the lack of a tiny, old-fashioned 320x240 screen and some cheap controls matters if you get a more powerful tool with greater capabilities. It seems that at least some of the disdain for USB devices on this blog comes from 'traditionalist' engineers (and the like) who seem to believe that any piece of test equipment that isn't a standalone device is not 'serious' equipment. This whole attitude strikes me as rather hilarious. I no longer own any standalone media devices (television, dvr, stereo, etc) - everything in my home being driven from HTPCs. I expect my lab to keep moving in that direction as well.
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I'm not saying that USB scopes couldn't be priced lower (I think Velleman has made inroads in this direction), but I think you're a bit out of touch with the market. The Picoscope 2207 - which has the 100MHz bw and 1GS/s rate - plus a built-in AWG and function generator - lists for $740 on the Picoscope website.
And only 40k record length. This kinda destroys all possible benefits. A 2ch scope with such a tiny sample memory buffer doesn't look like a real bargain for this price.
The weird thing is that although I work with windows based touchscreen scopes almost every day and at the same time like my el cheapo USB logic analyzer, I still have strong feelings against an USB scope. Firstly, for daily work, it would be only acceptable with a 2nd screen. Maybe somebody comes up with a standalone unit that is using a fancy tablet/pad as control and display unit. Apart from this, the problem remains that USB based devices with vendor specific drivers will quickly become outdated as will the control software. You can use a standalone scope that is 20 or 30 year old and you will still be able to use the current scopes in ten years even if they're based on Windows XP or Windows 7 which will then look like DOS for us right now.
But you can kinda bet, that even big brands won't support you for ten years with USB drivers and software updates. Not talking of small companies that might not even exist any more in ten years. This is an acceptable risk for a logic analyzer for a few hundred €, but it's just a bad idea for scope that costs a few thousand €.
So honestly, I don't believe that USB scopes in their current form will ever take a big share of the market and USB3 won't change this in any way.
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Stuff like measuring in the sample data
Agilent measures in the sample data , not on screen. On live data the input attenuators and timebase are reprogrammed on the fly. They have a large offset range to do this. you can actually see a 1vpp sinewave superimposed on a 30 volt dc signal.. the input stage has a dac that feeds into a summing amplifier...
Gating for measurements
explain 'gating' please ... do you mean triggering or do you mean the capability to stop a recording when nothing is going on and then continue ? Agilent calls this 'segmented memory'
Some of their low end scope have that but it is an option you need ot pay for. it is not standard.
the Agilent DSX3000 has no button to switch between auto/normal trigger mode though this is something that you need all the time.
Hitting a button repeadedly cycles through modes on some agilent scopes. so if you press the 'trigger' button the trigger menu comes up , hit the same button again and it changes the most logical setting ( in this case trigger mode ).
Generally, I'm underwhelmed by the displayed precision for cursor positions and measurements. With 1GSa/s and above, it should be somehow possible to measure if a pulse is 100µs or 100.01µs. That's 10ns and with 1GSa/s 10 points in the sample data.
the way you do this is by making a split view and zooming in on both edges. Rising edge in window 1 , falling in window 2. Then you get the required number of digits. if you zoom all the way out they faststep the cursor and turn off the trailing digits since they never change anyway... There is no point in showing 1.1000000000 . As you zoom in you get more trailing digits.
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I REALLY wish there was competition , i mean like okay 1Gigsamples ... What's the speed of a standard ADC converter in a off the shelf notebook you find now?
They have 24 bits 5gigsamples ADC's in there.
AND quad-core 1.4GHz 35W chips ... i mean what's stopping agilent to make cheaper stuff ? They have HP by their side and a fab of their own ( they make the megazoom asics so i assume they have a fab of theirs )
what have you been smoking ?
notebooks with 5 gigasample ADC's ? and 24 bit ? you have no idea what you are babbling about do you ?
Agilent has nothing to do with HP anymore. they long ago went separate ways. Neither Agilent nor HP have a waferfab (for digital monsters) at their disposal. The fabs went to Avago..
Besides those fabs are for optical things.
I know who fabs the agilent ASIC's ( can't tell you though ... NDA .. ). Those chips are extremely expensive due to the large amount of SRAM that is on board. The sram has to be able to run at full speed. Second problem is that they use gigantic internal pathways and have hardware assisted processing. The development costs of the Lynx ( Lynx is one of the megazoom Asic's ) are staggering. With the relatively small volumes they run a single chip runs well over a thousand of dollars.
The chipset in a 35000$ agilent scope costs them easily 15K$ to just fab alone ... An infinivision chip with 64 of 128 meg ram can handle 1 channel (so you need 4 of these beasts... in that 35K scope) add the multistage pipelined A/D needed per channel on there and you hit that 15K$ mark without problems...
The slower/cheaper machines use external ram modules.But the asics are still very expensive.
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And only 40k record length. This kinda destroys all possible benefits. A 2ch scope with such a tiny sample memory buffer doesn't look like a real bargain for this price.
Hmm... no one said it was a bargain by any stretch of the imagination. In fact, I think alm and I agree that prices have to come down.
Apart from this, the problem remains that USB based devices with vendor specific drivers will quickly become outdated as will the control software. But you can kinda bet, that even big brands won't support you for ten years with USB drivers and software updates. Not talking of small companies that might not even exist any more in ten years. This is an acceptable risk for a logic analyzer for a few hundred €, but it's just a bad idea for scope that costs a few thousand €.
First, we're talking about the low-end of the market. How many people will be using their Rigol DS1052E in 20 years? Secondly, I'm still using PC tech-hardware that is more than 10 years old - and with the advent of USB, the only significant change in Windows drivers was going from 32 to 64 bit (which many people haven't even bothered to do yet). The driver problem was much more significant in the 90's then it has been in the last 10 years, so I don't agree with your assessment of the problem.
So honestly, I don't believe that USB scopes in their current form will ever take a big share of the market and USB3 won't change this in any way.
Again, 'a big share of the market' is not even close to what I wrote, which was, '...USB 3.0... might very well make USB scopes, for many people, the bang-for-buck match of...standalone DSOs.'
My argument was that USB 3.0 might help drive the price down on USB scopes for the low-end market. Of course, I could be wrong about this - we'll have to wait and see.
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It may be usable on lower sampling rate, just like the long memory option on Rigol scopes, but at that point you're saving the relatively cheap DRAM, not the expensive RAM that can run at full speed. Not sure how much BOM costs this saves, especially if you factor in the premium for USB 3.0 transceivers.
Well, it seems pointless to argue this. You don't seem to feel that USB 3.0 scopes will make any difference in the market - I disagree. We'll just have to wait and see.
Sure, it has more features, though I'm not sure the Agilent is a fair comparison, since its banner spec is the fast update rate. My point was that this is the cheapest scope made by Picoscope (and I can't think of too many cheaper competitors) that exceeds the entry level scope which has been dominated by the Rigol DS1052E/1102E for the past five or so years. And you pay $600 extra for the lack of screen and controls.
I'm not saying that USB scopes couldn't be priced lower (I think Velleman has made inroads in this direction), but I think you're a bit out of touch with the market. The Picoscope 2207 - which has the 100MHz bw and 1GS/s rate - plus a built-in AWG and function generator - lists for $740 on the Picoscope website.
Also, I don't personally feel the lack of a tiny, old-fashioned 320x240 screen and some cheap controls matters if you get a more powerful tool with greater capabilities. It seems that at least some of the disdain for USB devices on this blog comes from 'traditionalist' engineers (and the like) who seem to believe that any piece of test equipment that isn't a standalone device is not 'serious' equipment. This whole attitude strikes me as rather hilarious. I no longer own any standalone media devices (television, dvr, stereo, etc) - everything in my home being driven from HTPCs. I expect my lab to keep moving in that direction as well.
I don't consider myself traditionalist at all (infact I'm always bitching about the lack of inovation in tech in general) but I have to strongly disagree here, in regards to people being stuck in there ways when it comes to stand alone equipment.
Whilst a USB scope has its place in controlled, or long term testing. For everything else, they'd be a pain in the arse. The ergonomics of it just aren't there, and nothing's going to change that in the forseabe future.
I don't think the HTPC analogy is entirely valid either. All that is really equivilent to is the increasing all-in-one functionality of DSO's.. i.e with a HTPC, you still sit in bed, or in your couch, and hold a remote.
It also reminds me of the touchscreen vs mouse +keyb debate.. Are people traditionalists for using the 30y/o mouse still? or is it just that touchscreens are a pain in the arse? (Case in point, I pulled my laptop out of my bag to reply to this, because, you guessed it, the phone s a PITA to type on).
What I would say instead, for cheaper scopes at least, is to stop this stupid trend of fitting huge screens and 1million buttons on them and instead create better PC functionality (which is typically crap, thouhg I haven't used them all) . Then you have the best of both worlds. "traditonal" , simple front panel controls, + a small screen, for "hands on" bench work, and all your fancy functionality, and screen real-estate on the PC for the tasks I listed earlier.
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Agilent measures in the sample data , not on screen.
I wish that was true, but unfortunately, it isn't. All the Agilent scopes I used up to now measured in the display data and changed the measurements when changing e.g. the zoom level in the already sampled data.
In the DSOX3000 manual, they also clearly state this:
"Measurements and math functions will be recalculated as you pan and zoom and turn channels on and off.
As you zoom in and out on a signal using the horizontal scale knob and vertical volts/division knob, you affect the resolution of the display. Because measurements and math functions are performed on displayed data, you affect the resolution of functions and measurements."
Indeed e.g. Lecroy salesmen are aware of this and put their fingers in the wound. Of course, Agilent scopes have other shortcomings, e.g. the extremely lacking trigger possibilities, the crappy menu structure with the Auto/Normal triggering hidden somewhere in a submenu instead of having a button etc.
explain 'gating' please ... do you mean triggering or do you mean the capability to stop a recording when nothing is going on and then continue ? Agilent calls this 'segmented memory'
Some of their low end scope have that but it is an option you need ot pay for. it is not standard.
No, segmented memory is something completely different. Gating is an essential measurement feature which let's you define the part of the sample buffer or screen range, where the measurement should be done. If you want e.g. to measure the PWM duty cycle in a pulsed PWM, a good scope let's you set the gating cursors at the start and end of the pulse and then the DC is only measured within this window. While Tektronix, LeCroy and even Rigol offer this option, Agilent simply ignores it. Instead they recommend to zoom into the area so the zoom window is misused as gating area. The problem is however that you can't control the size of the zoom window exact enough for this to work.
Hitting a button repeadedly cycles through modes on some agilent scopes. so if you press the 'trigger' button the trigger menu comes up , hit the same button again and it changes the most logical setting ( in this case trigger mode ).
Even if this worked (I don't think it does for the MSO7000A we have at work), it's still a workaround and a very dumb design decision to leave this button away.
the way you do this is by making a split view and zooming in on both edges. Rising edge in window 1 , falling in window 2. Then you get the required number of digits. if you zoom all the way out they faststep the cursor and turn off the trailing digits since they never change anyway... There is no point in showing 1.1000000000 . As you zoom in you get more trailing digits.
Which just proves that it measured in the display data and the scope cripples the measured accuracy by weird implementation. Besides, if you zoom out again to make a screenshot of the signal and measurement, you get the imprecise value again. So no way to make a sensible screenshot for documentation. And yes, it makes a lot of sense to show 6 or more trailing digits if they are based on the actual sampling data. E.g. in a recent case, I needed to test if a period changed from 100µs to 100.01µs. Impossible with the Owon, pain in the ass with an Agilent MSO7000A, piece of cake with a Lecroy 6Zi. Hell, you can even make a statistical analysis in a gating area (including a histogram) and so detail analysis in WaveScan mode. This is a bit of luxury of course. But a full resolution (independent of zoom level) automatic measurement in a gated area should really be available in this price range. And AFAIK no single Agilent scope can do it.
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I REALLY wish there was competition , i mean like okay 1Gigsamples ... What's the speed of a standard ADC converter in a off the shelf notebook you find now?
They have 24 bits 5gigsamples ADC's in there.
AND quad-core 1.4GHz 35W chips ... i mean what's stopping agilent to make cheaper stuff ? They have HP by their side and a fab of their own ( they make the megazoom asics so i assume they have a fab of theirs )
what have you been smoking ?
notebooks with 5 gigasample ADC's ? and 24 bit ? you have no idea what you are babbling about do you ?
Agilent has nothing to do with HP anymore. they long ago went separate ways. Neither Agilent nor HP have a waferfab (for digital monsters) at their disposal. The fabs went to Avago..
Besides those fabs are for optical things.
I know who fabs the agilent ASIC's ( can't tell you though ... NDA .. ). Those chips are extremely expensive due to the large amount of SRAM that is on board. The sram has to be able to run at full speed. Second problem is that they use gigantic internal pathways and have hardware assisted processing. The development costs of the Lynx ( Lynx is one of the megazoom Asic's ) are staggering. With the relatively small volumes they run a single chip runs well over a thousand of dollars.
The chipset in a 35000$ agilent scope costs them easily 15K$ to just fab alone ... An infinivision chip with 64 of 128 meg ram can handle 1 channel (so you need 4 of these beasts... in that 35K scope) add the multistage pipelined A/D needed per channel on there and you hit that 15K$ mark without problems...
The slower/cheaper machines use external ram modules.But the asics are still very expensive.
K, i stand corrected i have been smoking weed.
What i meant was DAC's which are a different area and are not that fast but more so around a capability of god knows how much pixels and 3x8bit
But yeah i know agilent went their own way and HP are not with them anymore and i am aware HP obviously can't fab anything but anyway i am very wrong that they have a fab, i apologize about that. I understand the need for NDA ;)
But we're not talking 35k scopes here, only 2k scopes
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http://focus.ti.com/paramsearch/docs/parametricsearch.tsp?family=analog&familyId=390&uiTemplateId=NODE_STRY_PGE_T (http://focus.ti.com/paramsearch/docs/parametricsearch.tsp?family=analog&familyId=390&uiTemplateId=NODE_STRY_PGE_T)
The cheapest 1GSa/s chip is like $170 - other chips go up to many hundreds of $. There is one chip that costs $9,000 ...
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I'd have to agree with marmad that USB 3.0 will allow attractive low price designs. It should allow streaming a couple hundred MBytes/sec.
I actually think PCIe based scopes are also ripe for massive improvements in price/performance. A PCIe 2.0 x16 slot can stream a few gigabytes/sec (my bland video card can transfer 5+ GBytes/sec from RAM). It should be possible to stream the sample data directly into GPU memory and then then have like 300 GPU cores processing the sample data. A cheap GPU has a gigabyte of RAM, and 300 GPU cores might be enough to process ALL the samples (i.e. like zero dead time), in real-time, for an intensity graded display. This will take a bunch of high performance software though, and the ability of oscilloscope companies to write good software has been mixed. I could actually imagine an open source GPU accelerated based oscilloscope, with the ADC card coming from somebody else, or multiple ADC card brands that all work with one piece of software. Notice that companies that make video cameras often don't make video editing software, and I could imagine a similar hardware/software split happening in test equipment. I'm probably biased though, I'm a server system software engineer, not an oscilloscope hardware designer. Still, for $150, I can now buy a TFLOP of computing power that pops into a $500 computer. A lot of GPU power is being built into the CPU now too. It would certainly be worth while for somebody to figure out what a modern GPU could do in terms of processing a sample stream. Like maybe 300 cores is enough to do software based triggering (i.e. finding cyclic patterns in the samples), making the ADC card even simpler. Being heavily software based, you could change the features by writing code. If it were open source, YOU could change the features, or you could pay for commercial software and let software folks change the features. So you need an analog front end, 1 to 4 ADC chips, an FPGA for PCIe bus interfacing, software, an appropriate computer with appropriate GPU.
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What do you expect your average PC to do with this hundreds of MB/s? You can't store it on disk, RAM will be filled up in seconds, and the CPU is probably quickly going to run out of steam if you want to do any kind of complex math at that speed. There's a reason why everybody uses FPGAs or ASICs in real scopes.
PCIe has a much faster interface, but again, what are you going to do with that data? Can you do DMA transfers directly into the GPU memory, or does it have to involve the main memory (my guess would be the latter)? PCIe 2.0 and low level drivers will be obsolete much quicker than even USB devices. PCIe excludes the use of laptops, so portability will be worse than stand-alone scopes. Even if this is feasible, then it probably needs some serious engineering effort from a company like Lecroy. Don't expect the big scope vendors to open up the market and make it more accessible to competitors, they like their expensive, monolithic and proprietary boxes. These are essentially Windows PCs with a bunch of scope hardware to do all the sampling and data transfer stuff.
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I'd have to agree with marmad that USB 3.0 will allow attractive low price designs. It should allow streaming a couple hundred MBytes/sec.
I actually think PCIe based scopes are also ripe for massive improvements in price/performance. A PCIe 2.0 x16 slot can stream a few gigabytes/sec (my bland video card can transfer 5+ GBytes/sec from RAM). It should be possible to stream the sample data directly into GPU memory and then then have like 300 GPU cores processing the sample data. A cheap GPU has a gigabyte of RAM, and 300 GPU cores might be enough to process ALL the samples (i.e. like zero dead time), in real-time, for an intensity graded display. This will take a bunch of high performance software though, and the ability of oscilloscope companies to write good software has been mixed. I could actually imagine an open source GPU accelerated based oscilloscope, with the ADC card coming from somebody else, or multiple ADC card brands that all work with one piece of software. Notice that companies that make video cameras often don't make video editing software, and I could imagine a similar hardware/software split happening in test equipment. I'm probably biased though, I'm a server system software engineer, not an oscilloscope hardware designer. Still, for $150, I can now buy a TFLOP of computing power that pops into a $500 computer. A lot of GPU power is being built into the CPU now too. It would certainly be worth while for somebody to figure out what a modern GPU could do in terms of processing a sample stream. Like maybe 300 cores is enough to do software based triggering (i.e. finding cyclic patterns in the samples), making the ADC card even simpler. Being heavily software based, you could change the features by writing code. If it were open source, YOU could change the features, or you could pay for commercial software and let software folks change the features. So you need an analog front end, 1 to 4 ADC chips, an FPGA for PCIe bus interfacing, software, an appropriate computer with appropriate GPU.
A cheap $150 GPU transfers 128 GB/sec to and from its on-board 1GB RAM. CPUs have onboard RAM of 3MB, 6MB or more, and can access it at clock cycle speeds (if you were to make a RISC chip with just the onboard cache and strip the onboard memory controller, parallel bus and cache controllers etc).
I think the only limiting technology is the ADC chip which from what I saw on the TI web page, very expensive. I am sure the technology is there but not the volumes of chips sold for CPUs and GPUs to price these chips at a few dollars each rather than many hundreds of dollars.
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What do you expect your average PC to do with this hundreds of MB/s?
To get an idea about this, you should be looking at the Velleman scopes. They are well-designed and built, but have modest bandwidths and are fairly inexpensive. They use the data being transferred to the PC for doing things like real-time Bode plotting. I've read of many people buying their scopes for this feature alone - even with the low bandwidths - since it isn't available on much more expensive scopes (or you have to write or assemble the code yourself with Mathlab, Labview, etc).
I was never suggesting that USB 3.0 was going to revolutionize the oscilloscope industry. My only point was that I believe the faster transfer rates were going to bring higher bandwidths and faster sampling rates to lower cost USB scopes like the Velleman scopes - just as it will to low cost USB logic analyzers - how could it not? And for more prospective oscilloscope buyers, if the PC software is good and feature-laden (and I believe it is for both Picoscope and Velleman) - and the bandwidth is sufficient for their use - and the price is attractive (Velleman levels - not Picoscope levels) - they will chose that option.
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...GPU...GPU...GPU...GPU...
Can we stop making stuff up? This is almost as bad as the thought that notebooks comes with gigahertz ADCs. Go read up on GPUs before you declare they they should come anywhere near an oscilloscope. GPUs are designed for massively parallel operations (operating on millions of individual pixels at the same time). Each individual core by itself is slow. Sampling a waveform is a serial operation. Triggering is a serial operation. You would be using the wrong tool for the job.
As for USB 3, I don't see that having any effect on the scope market. There's no real incentive to use it. If it let you do gigabit transfers, then I could see companies jumping on it because then all the scope would need to do is digitize the signal and send it to the computer. You would cut out a lot of parts and could put all of your cost into using a fast ADC. All a USB scope does is cut out the need for a screen. There's no other benefit to building one as a company, and most users see the lack of a screen as a negative.
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If it let you do gigabit transfers, then I could see companies jumping on it because then all the scope would need to do is digitize the signal and send it to the computer.
Um... I think you mean gigaBYTE transfers, don't you? Because It DOES let you do gigabit transfers - 5Gb/s max. In terms of transferring captured data, probably something closer to half that (2.5Gb/s) when you consider overhead. That means it's theoretically feasible to build a USB 3.0 scope with a 300MS/s rate (30MHz bandwidth?) that sends the data directly to the PC.
There's no other benefit to building one as a company, and most users see the lack of a screen as a negative.
This belies the fact that there are already dozens of USB scopes - introduced, for the most part, after the 2.0 spec. was adopted. And again, I personally don't see the lack of a tiny 6" screen as a negative if I'm looking at my real-time waveforms on a 24" monitor. But, hey, that's just me.
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and most users see the lack of a screen as a negative.
That and the lack of real knobs. And typically the lack of isolation.
This belies the fact that there are already dozens of USB scopes - introduced, for the most part, after the 2.0 spec. was adopted.
And most disappeared from the market faster than they were introduced, are rubbish overpriced toys or ended up in a market niche.
if I'm looking at my real-time waveforms on a 24" monitor.
There is no such thing like looking at realtime waveforms beyond a few Hz. Your eyes aren't fast enough to follow a high frequency signal, your oscilloscope updates its screen much slower than a high frequency signal comes in, and your oscilloscope has a deadtime where it doesn't even look at the incoming signal at all.
And 24"? Well, the key in seeing what you want is not looking at endless rubbish, but learning to use the trigger to get what you want to see.
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If it let you do gigabit transfers, then I could see companies jumping on it because then all the scope would need to do is digitize the signal and send it to the computer.
Um... I think you mean gigaBYTE transfers, don't you? Because It DOES let you do gigabit transfers - 5Gb/s max. In terms of transferring captured data, probably something closer to half that (2.5Gb/s) when you consider overhead. That means it's theoretically feasible to build a USB 3.0 scope with a 300MS/s rate (30MHz bandwidth?) that sends the data directly to the PC.
There's no other benefit to building one as a company, and most users see the lack of a screen as a negative.
This belies the fact that there are already dozens of USB scopes - introduced, for the most part, after the 2.0 spec. was adopted. And again, I personally don't see the lack of a tiny 6" screen as a negative if I'm looking at my real-time waveforms on a 24" monitor. But, hey, that's just me.
I agree with you, 5gigabit max but i have no knowledge of data transmission so i cannot comment further.
As for because i'm using a 22 incher i find it massively easier to track measurements down i mean like you get lots of clarity and resolution and if the screen goes i only need to replace the screen not the entire scope, but i would prefer the MFCTRS to place a big hunkin high speed sram and only send data not all at a time
BAW, erm, let's put something into perspective... would you rather view all 4 channels(eg) on a 8" or a 24" ? It's easier on the eyes
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Recently I just got 7102V and I'm satisfied. Till now I've not seen any of the previous problems like backlight, or Channel one noise yet ..., By the way I'll check more. Firmware version is 2.6.1
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Recently I just got 7102V and I'm satisfied. Till now I've not seen any of the previous problems like backlight, or Channel one noise yet ..., By the way I'll check more. Firmware version is 2.6.1
AFAIK it is functionally same as 2.5.1
(it is also oscilloscope product version, not exactly FW version.)
Owon display show "Version" not Firmware version if think features and user interface (UI)
Example, if something change in HW it may also affect this version number but with user eyes it is same. (service need know) Sometimes there may be manufacuring reasons for do some small component level changes but for specs or UI it do not mean anything. For end-user it is same value.
It is littlebit "confusing" but it is Owon way to do it and that's it.
I have also shortly looked version 2.7.
I have not find any functional or stability difference if look with user eyes. But in service level it mean "something".
It works just same as 2.5.1 or 2.5.1.6
(2.5.1.x.x is latest software shared by Owon as update)
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Special CH1 noise issue you can not find becouse there is not it!
This issue was solved last year! And it was only in some manufacture lots.
TFT back light control have generated some amount of noise to channels in some manufacuring lot and it is solved also. If someone get this from some seller stock, there is solution and Owon will help to remove this problem.
I will ask Owon: Why make changes to good product. Please do not make changes if all is ok.
Good example was this original TFT back light control circuit. It was good. It works ok. It can adjust also light from very dim to full. Not only numbers but also real light intensity.
What was problem/reason for make next, next and next changes. Nothing. Total lack of experience? If designer can not read some components datasheets right or understand these, what he is doing in design team? It is best to send him out for play mahjong and not gambling with designs.
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Could someone please tell me is there a latest release/model/version of the SDS1702 to look for when buying? I would like to avoid buying some old stock, if at all possible.
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Could someone please tell me is there a latest release/model/version of the SDS1702 to look for when buying? I would like to avoid buying some old stock, if at all possible.
My opinion is that there is not any seller who sell this OLD model what is OP rewieved in this topic.
If you want highest BW try buy 2.5.x.x version.
If you want later version with reduced BW buy new 2.6.x.x --->
(yes these MAYBE can modify IF really want higher analog front end BW becouse... but it is also good to understand what all things it means if BW is more wide.)
Of course reduced BW have less noise.
This is also explained in many papers published by Hewlett-Packard and later Agilent.
There is no need worry what version you buy. All these are good today and well better than most of others in this class if look signal quality.
How it can buy TV or computer if do not know that power supply is rev b.2.1 and not crap b.2.2. No one tell you what is inside and what version things there is and still model is exactly same. How it can buy? What makes oscilloscope different.
There is specifications. Do not believe you get anything more.
Do we really know and realize this or same kind of sentence what reads nearly every place.:
Well known Fxxxx:
"NOTE: The design of this instrument is subject to continuous development and
improvement. Consequently, this instrument may incorporate minor
changes in detail from the information provided in this manual."
And it really mean it in all meanings what it may mean.
How I can buy Fxxxx product?
<kind smile>
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Hey thanks. I presume 1.5.x and 1.6.x is the firmware version that can be seen on the screen so I can ask the supplier to send me a "1.6.x" version?
All I wanted to know is that I am not buying some old stock that, as someone said above, is not made anymore, receives no more software updates and has a ton of bugs that have been fixed in the later versions.
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The newer ones come with LAN right ?
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The newer ones come with LAN right ?
It is factory default, not option. It have been around half year. (still some shop want more money if you want LAN as option. (If someone do not want LAN, I do not know how they do.. )
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When we say LAN option does this mean an ethernet port like a printer so that a PC may connect to it ?
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When we say LAN option does this mean an ethernet port like a printer so that a PC may connect to it ?
LAN port is just normal (but slow) ethernet and physically it have "RJ45" connector.
Yes you can connect all xx number of classroom scopes to one hub and then teacher can read all scopes or show example one selected scope on the big classroom screen.
Or you can install one oscilloscope to some system in China or neighbour home and read/watch it in Zimbabwe or in you car over internet connection. (pity it is only for read oscilloscope)
If you can read User manual maybe it help something.
If need just connect one Oscilloscope to PC on the same or near table there is not any advantage with LAN. (also USB is faster)
From Oscilloscope you can not "send" anything to ethernet or USB (I mean example image to printer. It is just for READ oscilloscope and anything else.
PC software is tiny and poor. It is made just only for reading data from scope. It can poll data continuously and save it to your disk. (screen captures, vector data or measurements) Also it can translate vector data to other format example to CSV for using with third party softwares. It is NOT as USB oscilloscope software what you can use from PC and command oscilloscope and chhange settings. It is just "read scope and save data to PC" (and convert .bin vector data files to .csv.)
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Thanks, I have now ordered one of these scopes and hopefully it will arrive soon.
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Hi!
I have SDS8202 scope and battery option for it, to measure signals in devices directly connected to AC power.
And when I have bought battery, I carefully read manual, and found that:
- "do not connect ground socket of probe to anything except GND AC terminal, or you will get big-bada-bum"
- "when workinh on battery power, always connect GND terminal on back of scope to real ground"
- BNC ground and ground terminal at back of scope connected together
So, is I want to see what happening after line filter and diode brigde, I cannot, even with battery. I should or leave scope ungrounded, or it can be broken, due to voltage difference between null wire in AC wall socket and ground after line filter and diode bridge (I just will connect it directly via probe GND -> scope GND -> GND wire of wall socket -> null wire of wall socket).
So, what should I do do correctly measure such signals with Owon SDS?
Leave GND unconnected?
Thanks for answer!
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I have only one idea:
1. Connect rear connector to ground
2. Do not connect probe grounds to anywhere
3. Connect probe signals to both points
4. Turn on Math -> Subtraction
But what I will get - I do not know, especially about noise.
I have tried some schematic (very simple): AC source -> diode brigde -> two lamps connected via multimeter in current meter mode (so multimeter worked as current shunt). I connected scope (without grounding and on battery power) to both terminals of multimeter and expected to look at current waveform, may be slightly pulsating.
But I was very frustrated - I got very noisy signal, that was distributed above (this was expected) and BELOW zero level.
So, I got almost simmertical AC current after diode brigde (but if I measure voltage with scope after bridge I see traditional picture of rectified AC).
WTF?
How theese two lamps can cosume negative current through diode bridge???
May be I have connected something wrong?
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What you see is correct. You can not just connect the 2 tips of each channel and expect a +- sum
The GND of the tip MUST be connected and it is always the GND of the P/Supply or Mains.
You have 2 choices, an isolation transformer EITHER on the Signal, safest, or on the DSO mains supply.
In the 2nd case, the GND of the DSO lead is still at mains, so you have to be VERY careful not to touch it,
unless you ALSO provide an Isolation transformer to the DUT. Then you can only touch ONE part at a time.
Isolated CRO leads are rare and expensive !!
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No, I have tried to connect ground and tip of one probe, on one channel, without Math.
My scope works on battery, so it does not need mains to work.
When I have tried to connect it without groundinghs, I got strange signal.
When I tried to connect rear ground connector to ground via resistor (for safety at start), power source was immediately turned off (protection).
So, for now I have no way to measure current (and get right results :)) in circuits, connected to mains supply?
This is sad. :(
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No, I have tried to connect ground and tip of one probe, on one channel, without Math
That's the only way it will work, unless you buy a special isolated probe or an isolated current probe.
ALL oscilloscopes have that issue - ie You HAVE to connect the GND wire of the probe, which then puts
the WHOLE oscilloscope at that potential. As I said, I OFTEN measure mains, Live side, BUT you need to
take precautions !!!! We use an ISOLATION transformer on the DEVICE under test. That gives us a
LOT of safety, as long as you only touch ONE connection at a time.
My scope works on battery, so it does not need mains to work.
Doesn't matter. The Probe GND is still Referenced (connected) to the oscilloscope GND / Frame etc
When I have tried to connect it without groundinghs, I got strange signal.
YES. The signal HAS to be across the probe tip and GND wire (which should be as short as possible).
When I tried to connect rear ground connector to ground via resistor (for safety at start),
power source was immediately turned off (protection).
Now you're experimenting in dangerous territory !! Don't do that.
So, for now I have no way to measure current (and get right results :)) in circuits, connected to mains supply?
This is sad. :(
See above. All in the same boat, all have the same options
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Sad, but I cannot use isolation transformer, because load can eat up to 300v/2kWt.
I know that electricity can move me under ground level :), that's bacause I used resistor and measured voltage on it, before any dangerous connections. But this is not main question.
Strange signal, below and above zero line was while scope was connected to signal source via probe tip and probe GND and nothing else. Scope was ungrounded, so rear terminal was left unconnected. Scope worked on battery. In fact, scope was connected only to signal source. No mains power, no grounding of scope itself.
I do not understand, why I got very strange AC waveform, containing negative levels - while measuring voltage on shunt in DC power without any inductive load (only two lamps).
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My scope works on battery, so it does not need mains to work.
But it does need ground to be safe. From the (Engrish) manual:
When powered by battery, the product must ground connection. To avoid electric
shock, there must be a ground wire connect between ground and the ground port (on
the back of product panel).
I do not understand, why I got very strange AC waveform, containing negative levels - while measuring voltage on shunt in DC power without any inductive load (only two lamps).
Capacitive coupling between scope ground and other circuits? Since a scope is designed to work with a low impedance to ground, parasitic capacitance between ground and other circuits is not usually an issue.
So, for now I have no way to measure current (and get right results :)) in circuits, connected to mains supply?
This is sad. :(
Try using a current probe.
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Question first> is this the place here to ask questions or make user comments and that type of stuff? or is there another place
Welcome to the forum. You would always start a new question in a new thread. You can simply create one in an appropriate section eg Beginners.
Adding to someone elses thread is called "hijacking", and in some forums, ppl can get real bitchy. Newbies are safe here though :-)
SDS7102V ... battery in and charged (green light) then turn the scope on and i have noticed when one uses the scope and then
turns it off the battery charge light is back on (yellowy red) ...
This is quite normal. Whenever a system starts up from cold and has a battery installed, it will always check the state of the battery !!
It often need to do that by trickle charging it for a short while until it figures out if it is charged or not. After all, with the CPU off, it can't tell what
you may have done to it. Generally, the battery is NOT in use while mains power is connected. Prolongs the battery life.
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EEEP!! Pic2 doesn't look right, but I don't have that scope, so I have no clue at this point.
Luckily there are MANY users here that do, and they can definitely help more. There's a seller here, aghp,
hopefully he can help, or START a new thread with the question.
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Now this doesn't sound good at all. Photos would help. On your original problem if you short the probes it will form an antenna and pick up a lot of noise; if you FFT it you may be able to identify the key sources, like radio stations. For checking the DSO inherent noise, you should short the input with a 50 ohm terminator.
http://www.tmworld.com/article/321927-Quantify_noise_with_a_DSO.php (http://www.tmworld.com/article/321927-Quantify_noise_with_a_DSO.php)
No it does not look right aye , i also left out some bits as i still feel like thread stealing now that i know i'm in the wrong spot ::) so i'll keep it short or not at all from now on , but more the bits are> i can see that noise in all signals displayed even in the 2 to 4v @20mhz range , it's superimposed on it , also the scope keeps seizing up and needs rebooting , and now as this is my first digital scope i seem to think that it is very slow sometimes and plays catchup on even basic signals , and there is nearly always a ringing in the center of the screen on a signal , anyway i have emailed OWON service and the ebay seller to see who wants to take up the issue and hopefully it'll be sorted out , and not solely from the money spent aspect , from the "i like the scope" aspect (if it was working correctly that is ;D ).
cheers , and thanks for the input.
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Here you may find some tests about Owon noise.
https://www.eevblog.com/forum/product-reviews-photos-and-discussion/improvements-in-owon-sds7102-hw/ (https://www.eevblog.com/forum/product-reviews-photos-and-discussion/improvements-in-owon-sds7102-hw/)
also here
http://owon.freeforums.org/ (http://owon.freeforums.org/) (it do not show images and links to Guests)
http://owon.freeforums.org/ (http://owon.freeforums.org/) (here are some copy becouse this show also links and images to guests)
As others have tell, probe is good antenna. It is just HF antenna after you connect GND wire to center tip.
There may be lot of RF noise in your environment.
What is your oscilloscope version?
Do you have 50ohm BNC terminator available? (for some tests)
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Guess you might as well face it ... you did get a lemon, sure sux. Hopefully the seller / manufacturer will do the right thing ASAP.
Good luck
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Becouse I do not know who is your seller and I do not know if they are professionals or just selling "nice boxes" I will try help littlebit..
First it need solve if there is problem in oscilloscope. This can do if do right things seriously.
)from Owon you can not now get any answer. (In China is now Dragon festival time and nearly all is closed)
But first. If you show some picture from test, please pick up image from scope screen using USB stick or using PC software.
Do not show these kind of PC software pictures what you show before. I want see authentick images from oscilloscope itself (scope TFT screen copy).
All next instructions do with oscilloscope continuously connected to powerline and battery fully charged or oscilloscope without battery module.
1. set scope to factory "default".
2. Keep oscilloscope powered on continuously 30-60min.
3. Disconnect all probes, wires etc so that all terminals are empty, even LAN cable and USB cable. Just scope alone without touching anything. Only wire connected to whole oscilloscope is powerline. Oscilloscope inputs need be just without anything connected.
4. Start selfcal and wait it is finished. Do not touch oscilloscope when it is running selfcal. Do not even keep your hand near input connectors.
5. Shut scope off and immediately on.
6. For sure all is defaulted do it now agen (so I can relly be sure it is default.)
Do not change anything after full factory default but just next .
Do not connect anything to inputs. (exept: IF you know what is 50 ohm terminator and you have these then connect these to CH1 and CH2 inputs and later tell if you have used these or just open inputs)
Connect usb to PC and look you can pick up screen image. (select "Image" in PC oscilloscope software ports setting)
And make settings where you want it save images.
7. Turn both channels Volt/div so that they both show 200mV (becouse they have 10x it is actually 20mV/div in scope BNC)
8. Change acquire lenght to 1M and acquire normal.
9. Change Horizontal speed to 100us/div
10. Change dipslay persistence to 2s
11. Let it run some seconds without touching oscilloscope and hand more than 50cm away from inputs.
12. With PC, pick up image then wait 5 seconds and pick up next image with same settings)
13. Turn both channels to 2V
14. Let it run some seconds without touching oscilloscope and hand more than 50cm away from inputs.
15. With PC, pick up image then wait 5 seconds and pick up next image with same settings)
16. Then take 50 ohm terminators out if you have used these.
Connect Owon probes to CH1 and CH2. Set probes to 10x.
17. set oscilloscope to factory default.
18. Connect BOTH probes together to 1kHz probe comp output. (in this time do not connect probe GND wires - both separately just floating.
19. Set Horizontal to 500us/div
20. Let it run some seconds without touching oscilloscope and hands more than 50cm away from probes or scope.
With PC, pick up image or two
Now you have 5 - 6 images.
Convert these .BMP to ecample .PNG using some software, example Irfan or what ever what can do it. (becouse .BMP files are 1.4M and PNG is maybe 20k.
Show here these images. I will look these and if there can see some problem I will tell it, if there can not see problem then we do more tests. But I can try help you only if you can follow exactly "instructions".
If there is something you do not understand please ask example using PM
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I repairing an SDS7102 which had been broken when high voltage was applied to inputs.
Few components on channel 1 and external trigger inputs were replaced and now device works good, but I've found one issue with external synchronization input:
I connect probes to channel 2 input and synchronization input and apply a composite video signal from my camera to both probes simultaneously.
Then I select a synchronization on video signal and an "EXT" source in the trigger menu.
In this mode trigger works fine, I can check this by disconnecting external trigger input to ensure that the oscilloscope is synchronized from external trigger.
Then I switch a synchronization source to "EXT/5" and see that synchronization does not work.
After some tests I've found that in video trigger mode the oscilloscope triggers on channel 1 input when "EXT/5" is selected in the trigger menu.
This is definitely a problem, but I don't know is the root cause hardware or software.
Thus guys, could you please check this on your devices - just apply video signal to channel 2 and ext trigger inputs and try to synchronize with "EXT/5" trigger source.
Device S/N is 71021209XXX with 2.5.1 FW.
Thanks in advance.
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Here you may find some tests about Owon noise.
https://www.eevblog.com/forum/product-reviews-photos-and-discussion/improvements-in-owon-sds7102-hw/ (https://www.eevblog.com/forum/product-reviews-photos-and-discussion/improvements-in-owon-sds7102-hw/)
As others have tell, probe is good antenna. It is just HF antenna after you connect GND wire to center tip.
There may be lot of RF noise in your environment.
Do you have 50ohm BNC terminator available? (for some tests)
right, in my environment a cheapo 50ohm terminator is picking up a lot of RF noise,
even a good one is still picking some crap up (no matter if BNC or SMA terminated).
I got the best results with piece of copper foil (alu is fine to) closing/shilding the BNC - but not shorting channel input to GND.
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Then I switch a synchronization source to "EXT/5" and see that synchronization does not work.
After some tests I've found that in video trigger mode the oscilloscope triggers on channel 1 input when "EXT/5" is selected in the trigger menu.
I've reproduced this on my unit. Thus it is a common issue.
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Hi Folks
I am new here but have been reading many post and watching daves videos for months. I figure I am now fully qualified to fix any broken Breast pump that may come my way! If not; depending on the owner I will do it the old fashion way ;D
Anyway I wanted to post and let you guys know I just pulled the trigger on a AKTAKOM ADS-2221MV with battery which is the same as an OWON 8202MV just a different sticker on the front which saves a lot of $$ and gives me a 3 year warranty that is covered by Aktakom in the USA so I don't have to ship it back to China if I have a problem.
I also purchased a AKTAKOM AWG-4110 function generator on a whim, I have no idea what re-branded generator this is so if anybody knows please let me know.
Let me say it's very nice to be on this Forum, you guys are very civil as compared to many forums I have been on. I am also a Ham Operator and have been an EE for about 25 years and a programmer for 10 years. I bought the OWON because my TEK 2430A finally died and to repair it I need another scope but unfortunately nobody I know has a scope or they have a rubbish 10 MHz model from 1960. So I decided after reading this thread to get the OWON and roll the dice.
I will post back in a few weeks when I have received it and done some tests using my Ham gear for analysis and see how she works out.
All the best guys and thanks for so much useful info.
BTW I really wish Dave would do an OWON review, it looks like you just won't dabble in low end DSO's market again and that’s sad because it just leaves Rigol as the only torn down reviewed scope. I respect Dave but come on you have 3 or 4 video's on Rigol why not give OWON a go and let’s see how she stacks up.
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Siglent SDG1010
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Siglent SDG1010
Thank you. I see it is also see the LeCroy Wavestation. Wow what a price difference between the Siglent and LeCroy, I wonder if they are exactly the same internaly?
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Same. Entirely same
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Received my OWON 8202V (AKA Akatkom 2221mv) and I must say I am very happy with it.
They seemed to have fixed many of the problems that were pointed out about the 7102.
1) The Buttons and knopbs all feel very solid the buttons to the side of the TFT have no play or wiggle in them as the whole button assembly seems to be mounted differently.
2) No noise in Channel one or any of the channels.
3) The fold out legs seem to be different because I don't have any problem with the unit sliding back when the upper buttons are pressed.
I ran her up to 150 MHZ with no problems, I will also did some extensive tests on accuracy up to 10MHZ and that seemed very good. I did find a slight Vpp difference but that might be cable loss so I will have to do a lot more testing to find out.
I will also be testing glitch capture and the Waveforms/S stuff. I can say that so far it has been very impressive, I will keep you guys informed or make a new thread. I have only had it for 14 hours so I got a lot to check before making a detailed post.
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An update on Item one of the 8202V. The right side function buttons do have a slight wiggle, I had to look at it under a bright light and noticed it.
Exporting a waveform is very nice feature, I like being able to open it up on Excel and graph it out. The 10M depth really generates a lot of data points so its not practical to export the whole buffer but it's great for exporting out a glitch or some event.
The Fan is whisper quite when the scope is in the normal bench position but it does make a whir sound if I lift up the scope while its on and the sound stays there for a 20-30 seconds after I put it back on the bench, almost like the spindle has to reseat itself.
Measuring voltages is kind of odd in that the 5V test signal registers as 5.040V to 5.120V. Not sure whats going on but I need a second scope to confirm the readings.
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Hi Tinhead,
Seeing how you are the foremost resident hacker of the Hantek dso5062b on this forum, I was wondering if the owon sds7102 can be hacked as well. Mostly, I see the firmware is the only major issue besides the low waveform refresh rate which I really care less about since I'm not using it to find glitches or rump pulses. Do you know what OS the sds7102 is running or if it is even possible to hack to get better UI? I'm deciding on the sds7102 and Hantek dso5062b. Great work on the Hantek dso5062b by the way.
Thanks,
Tim
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Measuring voltages is kind of odd in that the 5V test signal registers as 5.040V to 5.120V. Not sure whats going on but I need a second scope to confirm the readings.
It happened the same on my SDS7102. If u move the wave down and decrease the V/div so the wave is 'bigger' gives more accurate reading ( I guess it has to do with the fact that it has a 8 bit ADC).
Cheers!
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Measuring voltages is kind of odd in that the 5V test signal registers as 5.040V to 5.120V. Not sure whats going on but I need a second scope to confirm the readings.
It happened the same on my SDS7102. If u move the wave down and decrease the V/div so the wave is 'bigger' gives more accurate reading ( I guess it has to do with the fact that it has a 8 bit ADC).
Cheers!
Thanks, that is probably the reason.
So far I am very happy with my 8202 it is working great, I have run it through lots of tests and so far I have found no issues with it. I think for it's price class it's one of the best 200 MHz scopes on the market.
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Hello!
Did anybody try new SW 2.8.1 for SDS7102? What difference from previous versions?
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I just installed it and I've noticed a few things:
First, the autoset and autoscale buttons now actually seem useful to me. The scope seems to autoscal and autoset much faster. So far I couldn't make it freeze yet, but on the other hand, I haven't done any extensive testing of the issue yet.
I also noticed that in some cases where the scope would previously draw output very slowly, it now works a bit faster. For example is I touch a probe tip when the scope is set to 1 V, 10 ms, 50 MS/s, it would take longer to show the signal on screen than it takes now when the scope is in auto trigger mode.
Next, I've noticed that when you go to measure->add->show all, the window with measurements won't disappear until the menu off button is pressed. Previously, it would quickly disappear making it difficult for me to read all the meausrements.
I've also noticed some changes in the help. It now mentiones the SDS5032E (which seems to be the 30 MHz version with some minor external changes), which wasn't there before and it also mentiones the VGA connector. I have the version without VGA and I think, but am not 100% sure, that previously VGA wasn't mentioned in the on screen help.
The "changelog", if you could call those 3 lines that, also tells us that the autoscale bug has been fixed (which is probably related to the autoscale improvement I've noticed) and that there's now a "current measurement function" and "remote control function". I couldn't find them yet in the menu on the scope, so I don't know how they work or what they do.
UPDATE: Well right after mentioning how the autoscale almost seems to be useful, I noticed a bug: If I set the autoscale on and allow it to touch vertical controls, it will go into a loop where it switches from 1 V/div to 2 V/div and back if it's connected to a 3.3 V source. Can anyone reproduce that?
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I just installed it and I've noticed a few things:
First, the autoset and autoscale buttons now actually seem useful to me. The scope seems to autoscal and autoset much faster. So far I couldn't make it freeze yet, but on the other hand, I haven't done any extensive testing of the issue yet.
I also noticed that in some cases where the scope would previously draw output very slowly, it now works a bit faster. For example is I touch a probe tip when the scope is set to 1 V, 10 ms, 50 MS/s, it would take longer to show the signal on screen than it takes now when the scope is in auto trigger mode.
Next, I've noticed that when you go to measure->add->show all, the window with measurements won't disappear until the menu off button is pressed. Previously, it would quickly disappear making it difficult for me to read all the meausrements.
I've also noticed some changes in the help. It now mentiones the SDS5032E (which seems to be the 30 MHz version with some minor external changes), which wasn't there before and it also mentiones the VGA connector. I have the version without VGA and I think, but am not 100% sure, that previously VGA wasn't mentioned in the on screen help.
The "changelog", if you could call those 3 lines that, also tells us that the autoscale bug has been fixed (which is probably related to the autoscale improvement I've noticed) and that there's now a "current measurement function" and "remote control function". I couldn't find them yet in the menu on the scope, so I don't know how they work or what they do.
UPDATE: Well right after mentioning how the autoscale almost seems to be useful, I noticed a bug: If I set the autoscale on and allowed to touch vertical controls, it will go into a loop where it switches from 1 V/div to 2 V/div and back if it's connected to a 3.3 V source. Can anyone reproduce that?
Thank you!
It is very detailed answer. Unfortunately I can't test this update, because I have a SDS7102115xxx and 2.5.1 version of firmware.
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SDS7102 V2.8.1 upgrade detail :
1. Add "current measurement" function;
2. Add "remote control" function;
3. Fix autoscale BUG
Can anybody explain what the "remote control" means in this context?
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That's actually a good question. I'd expect that the main problem is the briefness of the change log. We can't pick up the context because there isn't any clearly provided. The scope on-board help doesn't seem to mention anything. My guess is that this will somehow work with PC software in a future version, but again that is just speculation.
Anyway, I managed to find the current measurement description. In the channel one and two help menu item after description of 1x/10X/100X/1000X probes.
The procedure is to go to channel menu and under probe submenu (H3 button) enable current measurement (F2) and using the multipurpose knob and F3 option select the conductance/resistance of the resistor. The lowest conductance that can be selected is 100 mS and highest is 1 KS. Since there's no coarse adjust knob, it's a bit hard to adjust the conductance/resistance and I don't like the range. For me 100 mS is a bit too high for lowest possible conductance and I feel that 1 KS is way to huge for a scope like this one.
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I have a problem to get readings in the Oscilloscope software when using LAN connection after the update. It's possible to get an image copy, so the connection is working. Anyone else having this problem?
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The LAN problem is solved... Don't install the new pc software before you uninstalled the old one. If you miss that you have to uninstall and install a couple of times and also delete all remaining files and folders before you are done. But after that it's no problem at all.
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Regarding the new function "Remote controle" there is a new part in the PC SW (2.0.8.11) where you can controle the oscilloscope remotely from your PC. Supports both USB and LAN. Neat.
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SDS7102 V2.8.1 upgrade detail :
1. Add "current measurement" function;
2. Add "remote control" function;
3. Fix autoscale BUG
Can anybody explain what the "remote control" means in this context?
Current measurement scale conversion seems fun, i just had a fast look, but i will make few tries with 1 ohm or so soon.
Remote control work fine, i didn't find a way to synchronize the software with the current settings of the scope itself, that should have been very useful. (ex. probe 1x on software, but 10x on the scope)...
Is the protocol between both available somewhere ?
AutoScale bug don't know i never use autoscale ...
:-)
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Has anyone tried v2.8.1.6 (red boxed in the picture) for older SDS7102? It did not mention any details as for the v2.8.1 update for the newer ones.(http://)
Edit: I just installed it. I think all 3 improvements (measure current, remote, autoscale fix) are there, though I did not really test them.
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Has Owon drivers for Win 7 64 bit?
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Has anyone tried v2.8.1.6 (red boxed in the picture) for older SDS7102? It did not mention any details as for the v2.8.1 update for the newer ones.(http://)
Edit: I just installed it. I think all 3 improvements (measure current, remote, autoscale fix) are there, though I did not really test them.
I've intalled the update on 1209xxx just it was released. New features are present.
But the remote control feature implementation is very poor.
Has Owon drivers for Win 7 64 bit?
Yes.
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Has Owon drivers for Win 7 64 bit?
Yes.
Ok, thanks!
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Has anyone tried v2.8.1.6 (red boxed in the picture) for older SDS7102? It did not mention any details as for the v2.8.1 update for the newer ones.(http://)
Edit: I just installed it. I think all 3 improvements (measure current, remote, autoscale fix) are there, though I did not really test them.
I've intalled the update on 1209xxx just it was released. New features are present.
But the remote control feature implementation is very poor.
I installed this SW. My SDS is 7102115xxx. All functions are working.
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Well one thing I've noticed about remote control is that it seems to have bugs related to the probe attenuation. It basically always considers the attenuation to be 1X when voltage scale is being set. If I use the software to set the probe to 10X and then set the scale to 1 V, the scope will change to 10 V scale instead.
Also software version 2.0.8.11 is needed for the remote control. Back when the firmware upgrade was released, the newest version was still 2.0.8.8, so for a while the remote control function couldn't be used.
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About remote control: when I open it’s window it is not update with the oscilloscope data.
The state of the SDS7102 is not read to computer, the values are right just if I change a parameter.
Is the same for you?
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Hi,
You might look around on the net. I saw some references to firmware updates for this scope. It appears that it may fix some of the screen update an jitter issues. I don't have any personal experience with the update yet.
Sam
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Hello, i have also made another post in a new thread but i thought that it would be better if i post it here where more people are watching.
To start with i own OWON SDS7102 and i have a problem with displaying the signal inputs.
It looks like an unadjustable offset has been added at both channels moving the waveforms at a very low point so that you can't see them on the display. Instead you see a DC line at the bottom of the screen like your input is out of the lowest range. I have tried adjusting the vertical position at the full top value with no result. I also tried all the Volts/Div but again no results.
With the following configuration: Menu Probe X1, Actual Probe switch to X1 as well as Volts/Div less than 200mV (the limit of first relay click heard) and the probe connected on the Probe Comp (5V Pulse) i can see a part of the waveform (i believe it's the top side of the waveform). If i move the Volts/Div to 200mV or more the waveform disappears and a straight line can be observed at the bottom of the display (like the normal DC line when there is no signal input but now it's at the bottom of the screen and you can't move it with vertical position button).
Instead of changing Volts/Div if the configuration is Menu Probe X1, Actual Probe switch X1 and Volts/Div is 100mV (Probe connected to Probe Comp) and i change Probe's switch from X1 to X10 the waveform also disappears (without any relay click) and a straight line at the bottom of the screen appears again.
By the last above test it looks like there isn't an input path failure but something is going wrong with the inputs signal offset or the inputs range.
Here you can see two videos i captured.
Changing volts/div while probe connected on Prob Comp
OWON SDS7102 - Problem (https://www.youtube.com/watch?v=UUoF8w50S0A#)
One of my last attempts i did was to update firmware to the latest one 2.8.1,
then restore default settings and do self calibration (after the update self calibration is a lot faster)
OWON SDS7102 - Problem (https://www.youtube.com/watch?v=HlrO3t7nhR8#ws)
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Here is another video.
Configuration:
Cable Probe X1, Software Probe configured to X1, Volts/Div 500mV, Voltage supplied about 25Volt DC
OWON SDS7102 - Problem (https://www.youtube.com/watch?v=Ys8h2hY7ej0#ws)
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Hello, i have also made another post in a new thread but i thought that it would be better if i post it here where more people are watching.
Actually, no offense, but you were right in creating the new thread - this is (or is supposed to be) a review (impressions) thread. You already had a knowledgeable Owon dealer (aghp) respond to you about the problem in the thread you created - you should be communicating with him - or at least posting your followup videos there. He is most likely the best person on this forum equipped to help resolve your problem.
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Hi,
I am in the UK and just about to buy an SDS7102 from Aidetek/smtzone. I just called them in the states to ask a couple of questions. Very helpful girl on the phone but one thing she couldn't answer was the approx date of manufacture (or serial number) for the units they have in their UK warehouse. Obviously I would like to dodge any older stock, so I wonder if anyone in the UK has received a SDS7102 from Aidetek's UK warehouse and what sort of serial number it had ? Long shot I know.
Thanks.
Cam.
UPDATE:
Ordered Tuesday 11th December, paid 30.00 GBP extra to have it shipped from the UK warehouse and avoid any import duty and delays, arrived Thursday 13th December. Serial number SDS71021223xxx. Very impressive service.
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Hi,
I am in the UK and just about to buy an SDS7102 from Aidetek/smtzone. I just called them in the states to ask a couple of questions. Very helpful girl on the phone but one thing she couldn't answer was the approx date of manufacture (or serial number) for the units they have in their UK warehouse. Obviously I would like to dodge any older stock, so I wonder if anyone in the UK has received a SDS7102 from Aidetek's UK warehouse and what sort of serial number it had ? Long shot I know.
Thanks.
Cam.
UPDATE:
Ordered Tuesday 11th December, paid 30.00 GBP extra to have it shipped from the UK warehouse and avoid any import duty and delays, arrived Thursday 13th December. Serial number SDS71021223xxx. Very impressive service.
Thanks for that Cam. I'm in a similar position. Did you ever get a reply on the serial number or did you just jump in with the purchase?
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This scope is looking good, it on my list for 2013.
I'm very interested how the FFT performs with deep memory, does the FFT performance actually improves with deep memory or restricted memory by software?
I know that FFT suffer issue with limited by memory and wish to check if anyone see the difference and see if FFT take advantage of full memory or just partial (ie screen).
I do not see FFT have average feature (where small FFT signal stand out from noise floor).
In regard to timebase, has new firmware rev has better zoom features or it remains essentially unchanged?
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This scope is looking good, it on my list for 2013.
I'm very interested how the FFT performs with deep memory, does the FFT performance actually improves with deep memory or restricted memory by software?
I know that FFT suffer issue with limited by memory and wish to check if anyone see the difference and see if FFT take advantage of full memory or just partial (ie screen).
I do not see FFT have average feature (where small FFT signal stand out from noise floor).
In regard to timebase, has new firmware rev has better zoom features or it remains essentially unchanged?
In manual:
"FFT function in this oscilloscope transforms 2048 data points of the time-domain signal into its frequency components mathematically and the final frequency contains 1024 points ranging from 0Hz to Nyquist frequency."
Here you find also some tiny tests with FFT (http://owon.forumup.com/viewtopic.php?t=79&mforum=owon) (not full tests but somethink more than nothing - I have so much work that I have not get time for do real deep full tests and also becouse it is only 8 bit resolution ADC quite cheap level oscilloscope FFT and not real spectrum analyzer... it can do what it can but in this class - it is good)
This datapoint amount is typical for this kind of oscilloscopes.
(clarif: memory selection do not change FFT resolution)
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Zoom:
Owon have selected this zoom without windowing. It is not bad after some experience of use it. (same kind of zoom was also HP used in some digital oscolloscope)
Personally I like more windowed zoom if there is one button for swap between windowed and full screen screen for "zoomed" trace.
Owon not windowed zoom works nice and zoomed signal is as good as not zoomed (trig and timing works as good as not zoomed).
It is littlebit pity they do not implement zoomed also becouse Owon have display what really can do it. (800x600) if compare example to Rigol DS1000 what have only 320x240 and there it is really small for windowed zoom. But there are not perfect machines. Pros and cons.
(Btw, today oscilloscope version is 2.8.2 (SDS7102V))
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I know that FFT suffer issue with limited by memory and wish to check if anyone see the difference and see if FFT take advantage of full memory or just partial (ie screen).
Neither the Owon or the Rigol or the Hantek scopes are very good at FFT. I don't know what your BW and budget requirements are, but if a good FFT in a DSO is something that's very important to you, you might want to look at the Hameg scopes: HMO722 / HMO1022 (http://www.testequipmentdepot.com/hameg/pdf/hmo_manual.pdf) - I believe they have the best FFT on the market in the lower end scopes. They can calculate FFTs using from 2048 up to 65536 points.
The Hameg scopes are a bit more expensive than some of the others, but they are a quality product - and you get a much better FFT, a lot more triggers, and other features which make the price difference a bit easier to take.
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Yes, Hameg and specially Rohde@Schwarz oscilloscopes are high quality products.
HMO 1022 is 2 channel 100MHz 2GSa / 1GSa/s, up to (real) 2000wfm/s and just if FFT is very important it have max 64ksample (32k resolution) one of most "high end" oscilloscope in this class.
It have very professional features.
Its price looks: here http://webstore.rohde-schwarz.com/mea/hamegr-hmo1022.html (http://webstore.rohde-schwarz.com/mea/hamegr-hmo1022.html) 1.3kEur + VAT? What means littlebit under 1.6kEur dependent EU country VAT%. (yes, exmple in Finland I can not buy from R&S Germany web store, I need buy it from R&S Finland web store, it is R&S policy.
Owon is around under 0.5kEur dependent of also seller. Some sellers are dropshippers and some sellers are professionals who also know really what they sell. You get what you pay.
keep care you buy version what is originally from owon accepted and sold for overseas sale. Only these have overseas warranty. Some cheap sellers do not never give any help to you if you meet some problems. There are lot of good trusted sellers available around of world. Just select them. Not chinese car-garage dropshipper seller who know only that "it have nice box and it is new".
after you buy he call his friend who caall his friend that some box need ship and he get maybe 5 yuan for eat.
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Its price looks: here http://webstore.rohde-schwarz.com/mea/hamegr-hmo1022.html (http://webstore.rohde-schwarz.com/mea/hamegr-hmo1022.html) 1.3kEur + VAT? What means littlebit under 1.6kEur dependent EU country VAT%. (yes, exmple in Finland I can not buy from R&S Germany web store, I need buy it from R&S Finland web store, it is R&S policy.
Owon is around under 0.5kEur dependent of also seller. Some sellers are dropshippers and some sellers are professionals who also know really what they sell. You get what you pay.
Yes, Kari - as I already mentioned in my message, the Hameg costs more than the Owon. But what you are willing to pay depends on what features are highly important to you - as well as how you plan to use the DSO.
Personally, I find it odd that anyone would buy an Owon or Hantek nowadays instead of the Rigol DS2072 - except for the following reasons:
1) You need a DSO immediately - and you just don't have an extra +€300 to spend now. So your plan is to replace this 'starter' DSO in the future (although it's more money in the long run).
2) You only need to use the DSO for the simplest possible repairs - and you will never make any money from using it.
3) You absolutely have to have battery portability at the expense of all other features.
Otherwise, why not invest for your future - save up the extra couple of hundred - and buy a vastly superior scope? Since the Rigol DS2000 series has been introduced, buying one of these €400-€500 DSOs is a little like paying 50-75% less for a new automobile which - while it does actually get you around - only goes 5kph.
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Here I find Rigol DS2102 (100MHz) around 1150,- (Batronix Offer)
Owon SDS7102V I can find around ~450 Eur from reputable sellers who may have also after sales support and warranty service locally and customer have posibility to test and check in semi professional lab if it pass for his needs.
Owon have naturally pros and cons. As all...
I'm littlebit surprice that so many professionals for real work buy these Owons today.
I know some arguments but they are these common... good support, reliable, small size, big display, high sampling rate down to slow horizontal speeds, battery of course. Also in trawel use around of worls, not big loose if damaged or loosed...
But this is NOT for deep lab work for example catch some fast clitches from digital signal streams... but I know lot of real industrial service work where this is just enough as F....e golden priced handhelds..
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Personally, I find it odd that anyone would buy an Owon or Hantek nowadays instead of the Rigol DS2072 - except for the following reasons:
2) You only need to use the DSO for the simplest possible repairs - and you will never make any money from using it.
3) You absolutely have to have battery portability at the expense of all other features.
Not starting anything here, but I find these comments over-the-top.
I bought the Owon because - It has a large hires VGA screen, it has a built-in battery, and pretty good specs. YES, it has limitations.
BUT, IF it was my only scope, I could easily make a shitload of money from it ! 40+ yrs in R+D. If I had a Tech who told me he could
only use an expensive scope, I'd sack him. A good Tech can work with whatever he's got, if NEED be, and do it WELL.
I bought the Owon mainly for EV motor / control calibration / tuning. IF I blow the scope, and failures in this game are quite serious,
I don't care. I'm NOT dragging my $30K or $50K LeCroys to the job !!
Since the Rigol DS2000 series has been introduced, buying one of these €400-€500 DSOs is a little like paying 50-75% less for a new
automobile which - while it does actually get you around - only goes 5kph.
I like analogies, but this is WAY off the mark.
I can state that, based on my last 40 yrs, the Owon would have been fine for say 90-95% of my work. YES, there are situations where the
Rigol would win hands down, but generally ANYONE who'd need that capability would be SAVVY enough to know what he (she) wants.
Sorry to butt in, but mis-information irks me. IMO, YMMV
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I bought the Owon because - It has a large hires VGA screen, it has a built-in battery, and pretty good specs. YES, it has limitations.
BUT, IF it was my only scope...
Hmm.. it seems to me the pertinent information here is that it's NOT your only scope. For those of us who can't afford the really great expensive scopes (which you obviously own many of) and have to suffice with a single DSO - the difference between paying €400 or €700 - and the added features and capabilities you get for that increase in price - might be a big issue.
I like analogies, but this is WAY off the mark.
So, you've used the two scopes we're discussing in-depth?
I can state that, based on my last 40 yrs, the Owon would have been fine for say 90-95% of my work.
That's YOUR work - it's not mine - or anyone else's necessarily.
And, BTW, you seem to fit into my category #3 from above perfectly - second cheap scope for battery portability.
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Here I find Rigol DS2102 (100MHz) around 1150,- (Batronix Offer) Owon SDS7102V I can find around ~450 Eur from reputable sellers who may have also after sales support and warranty service locally and customer have posibility to test and check in semi professional lab if it pass for his needs.
1) You're comparing the model prices based on bandwidth. But why not compare on sample speed? 2GSa/s: DS2072 = €710 / SDS8202V = €635 (Batronix prices excl.) - a little bit closer in price. Or why not compare model prices based on wfrm/s? Or on the width of the horizontal scale, etc?
2) Unfortunately, although people have looked into, it doesn't seem to be possible to 'increase' your bandwidth (or other features) after purchase of Owon SDS models. This is not true for the Rigol DS2000 series. Also, although people are being quiet about it, the current firmware of DS2000 appears to have a bug which allows you to keep using the Options (56MPt memory, protocol decoders, extra triggers - an added €660 value) forever - or at least until you decide to upgrade your firmware ;)
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So, you've used the two scopes we're discussing in-depth?
Emona is just up the road from us, I did "play" with one and was impressed. Consequently, 2 of my friends have
recently bought the 2/4 channel Rigols, based on my recommendations. In these cases,
both work on high-end stuff MOST the time (S/Modes / Motor controller designs) and both had lotsa loot. No contest.
If you read my post carefully, I did NOT trash YOUR post. I just had issues with TWO of your "absolute definitive"
statements, for WHICH I supplied alternate examples. (=examples)
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If you read my post carefully, I did NOT trash YOUR post.
Well, I guess that's open to interpretation - using phrases like "over-the-top" and "WAY off the mark" might be considered slightly 'trashy' :) But perhaps you misunderstood my meaning: I wasn't suggesting you COULDN'T make money with an Owon - I was suggesting the opposite: that IF you can make money with your DSO, why not invest a little more now (which you will earn back) and get a much better tool for doing that? Whatever it's advantages are (and it certainly has some - I've recommended it in certain circumstances to many people, in both my posts and reviews), the Owon is just not a very good DSO for certain things (such as the design and debugging of digital electronics).
That post was aimed towards people that have to make do with a single DSO for several years. If I could justify two DSOs, I'd likely still have my SDS7102 for certain battery-operated situations. But if you know that you're only going to have one DSO to use for awhile - the decision to spend less or a bit more now, IMO, got radically different once the DS2000 series was introduced. You just can't look at the available options - and value per $/€ spent - the same as you could a year ago.
... and both had lotsa loot. No contest.
Again, I don't think this is an issue about 'lotsa' loot anymore - rather a bit more loot.
I just had issues with TWO of your "absolute definitive" statements, for WHICH I supplied alternate examples. (=examples)
Well, my 5kph automobile example was certainly partially a joke - I just came up with the figure off the top my head using Rigol's ~50,000 wfrm/s vs. Owon's ~40 wfrm/s - and their associated blind times - for inspiration - I never suggested that my analogy was "absolute definitive". But I would suggest that my statement that the Rigol DS2072 is a vastly superior DSO to the Owon is definitive. Do you disagree with that?
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Here some tiny tests with SDS7102V HW/FW 2.8.2.
Here some tests with new SDS7102V version 2.8.2.
Note: before I have made risetime test with Tektronix generator. In specs it have <1.3ns risetime but I have measured it... it is far more fast (perhaps under 1ns). It is clearly faster than this now used HP. So, this affect some amount and so these results are not directly comparable (exept if you think what itr affect... also pulse shape is littlebit different)
Risetime tests made using HP8161 pulse generator around 1.3ns specified risetime and measured around 1ns. 2meter coaxial cable and Tektronix 50 0hm feed thru terminator in scope input. (this method is not best possible but littlebit better than BNC T with terminator and this is also comparable to my other tests. Note that with this method there is not 50ohm impedance becouse oscilloscope input is not "ideal". Specially in this case there is parallel capasitance what destroy matching. And this is case also with many cheap oscilloscopes what do not have true 50ohm impedance inputs but there is just relay and 50 ohm resistor without real impedance matching for whole frequency area as is case in many expensive Tek and HP ("Agilitylend" who nearly destroy HP to level "all can do these cheap plastic boxes" and somebody who today try destroy Tek downcounting have started.)
All images, exept last one only CH1 in use.
Sweep tests and sinewaves are from Agilent 8644B signal generatorwhat have very good flatness and extremely good signal purity in this frequency area.
Same notes and connection as risetime test exept cable is around 1m.
Note: Voltage bands are I: 2mV to 100mV, II:200mV to 1V, III: 2V to 10V
(http://i181.photobucket.com/albums/x2/aghp55/SDS7102V_linswp_1_250_50mV.png)
V/div 50mV (band I), sweep start green line and in end it go back to starting freq. Sweep is linear and sweep time is 100s. Oscilloscope 10s/div. One div is 25MHz. Oscilloscope is in peak mode.
-3dB point is around 175MHz related to 1MHz signal level.
(http://i181.photobucket.com/albums/x2/aghp55/SDS7102V_linswp_1_250_500mV.png)
V/div 500mV (Band II), sweep start green line and in end it go back to starting freq. Sweep is linear and sweep time is 100s. Oscilloscope 10s/div. One div is 25MHz. Oscilloscope is in peak mode.
-3dB point is over 200MHz (225MHz) related to 1MHz signal level. (note shape... perhaps if better impedance matching there is less "waves" in shape and it is possible then -3dB point may move down (or up))
(http://i181.photobucket.com/albums/x2/aghp55/SDS7102V_300MHz_500mV_persist.png)
Same settings and source level, sinewave 300MHz and infinite persistence for looking if some trig instability and/or vertical wobbler.
(freq counter max is around 320MHz and signal trig limit (single CH in use) is around 450MHz (but out of signal level specifications for trig of course)
(http://i181.photobucket.com/albums/x2/aghp55/SDS7102V_rise_50mV.png)
Risetime Voltage band I. Signal shape is very good. Risetime (frequency response) is clearly better than specified. (<= 3.5ns)
(http://i181.photobucket.com/albums/x2/aghp55/SDS7102V_rise_500mV.png)
Risetime Voltage band II. Signal shape is good. Risetime (frequency response) is clearly much better than specified. (<= 3.5ns) around 2.2ns in this test system. (real risetime is littlebit better but this moment I have not available better signal source. This can see if analyze image where is persistence and visible corner wobbling - also FFT tell same story)
Here now and later some more tests. (http://owon.freeforums.org/post48.html#p48)
Opinions are extremely important but real data is.... sometimes also good to know.
-aghp
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Hello, I have bought the OWON SDS7102V and have upgraded it to version 2.8.1. I am having a great problem with low input signals : the display is noisy and does not "lock on".
I have taken a picture although you need a video to see the problem clearly. Basically the curve moves all the time, jumps around, makes it impossible to read.
The picture is with a signal of 80mV pk and sensitivity of 20mV
With 800mV pk and sensitivity of 200mV it is more stable but still jumps occasionally and there is a bit of noise
With 8V pk and sensitivity of 2V it is very stable and almost no noise
Please help.
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First
This image can not see nearly anything due to image quality.
If you have this quality of picture why you send it with this image size?
Owon have USB and you can take display image to USB and there can see all exactly.
In very rare cases problem solving need video. And more less if vidoe image is poor shaking quality as usual and no any other documentation.
But there is some mysterious in image what can detect.
Look first these trigger levels and more... visible is CH1 but it seems you have ALT mode in trig.
Please now first. Read user manual from beginning to end.
Then do factory setup. (utility -> adjust -> default.
Then connect ALL things out from every input.
Then do selfcal after oscilloscope have been least half hour on. And do not touch anything during selfcal. Specially do not touch input connectors.
Then do NOT connect anything to CH2
Then set probe settings in scope to 1x
Only CH1 on (CH2 off)
Push CH1 vertical position, it moves to center.
Push trig level knob, it moves trig to center level zero.
Turn CH1 for 5mV/div
Turn Time/div to 500us/div
Do not change any other setting (after default and cal)
Take 1kHz sinewave from good and clean source using coaxial cable with BNC
Connect 8mV p-p 1kHz sinewave to CH1 input.
You see accurate and stable triggered signal what stay on its place as rock.
Drop pp level to 4mV and change CH1 to 2mV/div
Still you see well triggered signal. If not turn trig level just small amount (+-1mV) up or down until it trigs.
Take direct pictures from screen so that things can see clearly.
If there is some jumping etc... you may use persistence for collect these to picture.
If NOT then we may start diagnose suspected problem inside scope.
Now I keep also supspected that problem is outside oscilloscope until more information.
Keep in mind that also probe may be broken and even if ok but it can easy also pick up noises if there is high noise fields.
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Thanks for your reply. I have spent a lot of time trying to set up the PC software so I can take those screen shots.
The oscilloscope was left running for an hour, then calibrated, then one probe inserted, just as you asked.
I have taken some snapshots but these are "still", they do not show you how much the wave "flickers" on the screen, I mean the wave jumps about all the time plus a lot of noise. The scope cannot "lock" on properly and not even with 500mV signals. There is a "click" when you turn the sensitivity to > 1V/div and then it is better.
If you look at the pictures below you can see the noise, but you cannot see how much the wave "jumps" about.
Picture 1: 2KHz sine wave - 80mV peak to peak
Picture 2: 2KHz sine wave - 40mV peak to peak
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Perhaps you did not read my message?
Try follow it.
And I ask Owon screen shot. It is exactly copy from TFT using simply USB stick but ok now you have communication so... you can take directly screen capture "image" (it is just as scope TFT copy) from Owon using this communication. (or with USB stick)
(image from display show all visible settings also so I can see where is your trigger level and what are other settings (and do these settings hand, not pushing auto button.)
Then I ask you use display persistence for collect all changes to same image. (some 1 to 5 second persistence is ok in this case.
Then I ask connect signal using coaxial cable for avoid posibility that you collect some terrible noise from enviroment with possible fault probe etc
First, try get this pure clean signal first directly to oscilloscope input without probe if possible so that there is no any posibility about external noise.
Please read this my before post and try follow it.... take Owon Image (direct copy from screen) Just as my some pictures you have seen. If you do exactly then I know how to look and think your result.
Im interest about what we can see if there is sure clean signal in scope input... and just all settings done how I have ask. (Including this "default")
After this result there is then more tests but first this.
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OK here are some pictures.
I think I have followed your instructions as much as possible. I have pressed 50% many times and also have manually turned the trigger knob, but nothing helps. I have connected the probe straight on to the tone generator. I have used two probes to make sure.
As you can see, even at 800mV there are issues. Screen persistence set to 5 sec. The last picture showed almost OK on the screen but the image was not that OK.
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1.
Ok, please do same things (one setup is enough) with only CH2 in use and of course trig also selected CH2.
Your probe is 1x and oscilloscope probe setting 1x?
One or two image with CH2 (same signal etc as with CH1)
Then do "default"
2.
Then
Connect just both probes to 1kHz probe comp output. Probe 10x and setting 10x (as default also)
Press just "auto" and select more or less periods visible.
Do not adjust anything! Only set display persistence to 5 second.
Then just one image.
3.
Then
agen default scope.
Do not connect anything to inputs.
Turn CH1 and CH2 to 20mV (it automatically turn BW on) (it is most sensitive setting 2mV but there is default 10x for probe)
Then set memory to 10M
Then set acquire mode to "Peak"
Time/div to 500us/div
Keep hands away from near inputs.
Press "Stop"
Change time/div to 1ms/div it zoom out.. (keep scope acquire stopped)
(you have now 10div long traces)
take Image.
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OK. I did as you said :-) Again, many thanks for taking the time to help me.
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You tell that you upgrade FW to 2.8.1.
What version it was before?
What is your whole serial number without last three digits?
How it works just before upgrade?
Have you find that problem start just after upgrade or just random time?
Lowest voltage band is 2mV to 100mV/div (if in scope input settings Probe:Atten:X1 (and directly input BNC or we have 1:1 probe (X1)))
(analog front end is divided to three voltage bands:
I: 2mV - 100mV
II: 200mV - 1V
III: 2V - 10V
All these have different signal pathway in analog front end.
Also trigger signal is splitted (before ADC) there to trigger circuits. )
It looks like there is now something wrong. (perhaps in Voltage band I but still all is possible)
2.1.
Do first scope default (Utility:adjust:default) and then only next things:
Connect probe to CH1.
Turn probe switch to X10
Connext probe tip to Probe Comp
turn Sec/Div to 100us (I want see also shape)
Display :persist:5s
(Display):Trig Freq: ON
Push Trigger "Menu" button once.
Then save "Image" with PC (in this time not with USB stick so I see trig settings bottom of screen)
2.2.
Then only touch CH1 Volts/Div knob
Turn it one step to 2V
Then save "Image" with PC agen.
Show these images.
If both give well trigged result there need continue some more tests. but if 2.2 or 2.1 (or both) give clear bad result then game over = scope need repair.
(of course there can do endless amount of tests but just after it is proofed there is fail do not waste time for testing.
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Version was 2.6.2 and serial is SDS7102V 1211675
It was the same before the upgrade, actually I thought the upgrade would fix it. Basically when the signal level is low (below 2V peak to peak) then the scope has trouble in displaying it, or locking on to it, or both.
Is there a way to put it back to 2.6.2 maybe so as to test again?
Following your instructions again:
2.1 pictures (both from PC and USB stick) = SN1.jpg and SN1-image.jpg
2.2 pictures = sn2.jpg and sn2-image.jpg
At the bottom of the screen, when I pressed "Trigger Menu" it said:
Single-edge, source-ch1, coupling-dc, slope-up, auto&holdoff, 1=1.000000KHz 1=_/ 0.00mV
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Version was 2.6.2 and serial is SDS7102V 1211675
It was the same before the upgrade, actually I thought the upgrade would fix it. Basically when the signal level is low (below 2V peak to peak) then the scope has trouble in displaying it, or locking on to it, or both.
But now we have 500mVp-p and it trigs perfect.
Becouse probe comp give 5Vp-p and probe is set 10:1 so oscilloscope BNC input level is 0.5Vp-p
With this level it trig ok with both voltage bands (I and II)
(I can see in image something what is not ok but I do not know if these noise spikes are from oscilloscope itself or picked from your enviroment. )
You have battery. Use it with battery. Go to place what is as clean as practically possible from all (electric) noise . (no computer, no switch mode "energy save" lightning etc etc )
No need post image now, only watch if these small noise spikes disappear (or change).
If you see these small spikes disappear or just stay, only tell it.
Then, whatever this show...
tell me if you have available reliable clean adjustable source for around 10 - 500mV p-p level square wave around 1kHz to higher frequencies. (if it have "50ohm" output then 5-250mV)
It need be so that you really know output level and that it really is clean from high noise etc.
(example some reasonable good function generator. And do you have available coaxial cable directly from generator output BNC to scope BNC.
If not... and still you have generator. It can connect with probe but probe GND need connect to BNC GND if generator have floating output! Not to generator ground.
(idea is that we need find reliable enough good quality signal for test trig with lower level. If we can not trust test signal it is waste of time and may lead only confusing)
Is there a way to put it back to 2.6.2 maybe so as to test again?
There not bridge left to go back with normal upgrade process.
My opinion is: it is not useful to go back in this case.
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Hello
I have disconnected the mains lead and took the scope around the house, the spikes remain. I have tried 4 different probes, CH1 and CH2, and the noise remains.
In the 1V/div setting, those spikes sometimes cover 25%-45% of the division, that is like 500mV "noise"!!!
The one thing that makes it slightly better is to switch the probe to 20MHz. Still I cannot display a 8mV pk-pk waveform or even a 80mV pk-pk because of all the noise.
I do not have a reliably clean source of low level signal to try with but I remember the old scope (20MHz analogue) was working quite well on those low level signals.
What would you suggest as next step now?
Thanks
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Hello
I have disconnected the mains lead and took the scope around the house, the spikes remain. I have tried 4 different probes, CH1 and CH2, and the noise remains.
In the 1V/div setting, those spikes sometimes cover 25%-45% of the division, that is like 500mV "noise"!!!
The one thing that makes it slightly better is to switch the probe to 20MHz. Still I cannot display a 8mV pk-pk waveform or even a 80mV pk-pk because of all the noise.
I do not have a reliably clean source of low level signal to try with but I remember the old scope (20MHz analogue) was working quite well on those low level signals.
What would you suggest as next step now?
Thanks
"The one thing that makes it slightly better is to switch the probe to 20MHz"
Without probe we see not really bad noise.
Probe connected to input - high noise.
It looks like probe itself collect noise from somewhere.
Try short circuit probe center pin directly to probe gnd.
Like image, so that short circuit wire make reliable contact and no extra wire what make any antenna.
How is noise now?
In my lab I have one energy saving fluorescent lamp where current control is made by switch mode regulator. With open probe I can collect lot of noise example 1 meter distance from this lamp.. With shorted probe.. just nothing.
Now if shorted probe is nearly without noise then it need find this noise source. Scope itself or something in your enviroment?
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Something about this old analog and then digital and noise.
Tektronix:
With analog oscilloscopes with CRT displays, the extreme ranges of noise are not displayed, because they occur quickly and infrequently, which means that the phosphor is lit quickly and infrequently, and thus those extremes are very dim or not drawn on the screen at all.
This means that analog instruments are not just displaying voltage against time, but in fact have a third dimension: Intensity. Intensity is related to frequency of occurrence of the signal. DSO oscilloscopes will show every hit with the same intensity, no matter how frequently a particular pixel is hit.
Now you have oscilloscope what is very sensitive and it have wide analog bandwidth before ADC.
If example in low speed (low samplerate) you see high noise there is also posibility that it is HF noise far over half of samplerate and what you see is alias produced by this noise.
Also if noise is random and high freq you really can not detect it at all from old analog oscilloscope phosphor. Simply it is far away too slow and perhaps also scope bandwidth is very limited compared to your Owon. If there is going high level 400MHz signal inside to scope you see it. (with low speed you may see its alias. And it is not limited just to 400MHz. You perhaps have seen FFT images from some tests. (example sweeped FFT freq response image. Also it is good to note that probe is good antenna specially very confusing if there is higher frequencies "on the air".
Here is this small tektronix pdf (http://www.tek.com/support/faqs/why-does-my-digital-oscilloscope-have-more-noise-then-my-analog-oscilloscope).. it may give some idea and it can think also for higher level displayed "noises".
I can make one image to you where Owon is collecting noise just with example open probe or short circuited with probe own GND wire. (it is now nice "loop" antenna.)
Probe GND is ok only for audio frequencies if you work in emi free enviroment.
Soon later I make some for just example.
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Some fun with enviroment noise.
Around 80cm to table is one fluorescent light... on the table ESD srface is open Owon probe x1
Light on and light off. NOTE: There is still one noise source lamp on around bit over 2m distance from table.
Then IBM laptop power supply and probe short circuited with its own GND wire.
Same with more fast speed. (and persistence 5s) It mostly somehow trig becouse this noise have so clear pulses.
Last some old Owon FFT sweep.
From Zero to 500MHz (500MHz is Nyquist "wall" with 1GSa/s) (if there is signal over 500MHz it is folded back to under 500MHz, this is also good to understand if use FFT)
Now there is 1GSa/s sampling and there can see how signal attenuate... but still not so much at 500MHz. Of course now if rise signal level it may rise to full, of course.
It is very important to realize... this analog "highway" bandwidth from BNC to ADC is just this with all samplerates! If there is AM or FM station near, if there us UHF TV transmitter near... or some other RF sources.. it may lead what ever kind of problems and it neet take care as designing how to connect probe and how it may affect measurements.
Independent of sampling speed this analog front end have wide BW road from BNC input to ADC input.
So, of course all noises can also produce high amount of noise and it may be direct noise or noise alias image.
Now of course if noise is high frequency signals it can reduce something if turn 20MHz BW but also this 20MHz BW filer on but also it only attenuate example 30MHz or 100MHz.. but it can not stop these.
It is more than one lesson to learn many kind of methods for right "probing". In many cases it is also difficult for peoples who have lot of experience with many kind of lab works in theory and in practice.
But... still we do not now know IF your scope have some real problem or what is this case.
I remember some people who have lot of experience with old 20MHz whatever name analog oscilloscope and then he get new digital oscilloscope and he see things what he have never seen before... he was so confused that he turn back to his old analog after small repair it.
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OK here is another picture.
I have used the oscilloscope's own 1KHz probe comp with a fixed resistor potentiometer with the two resistors straight on the pins, and here is the noise . The pot is 10K/470R.
This picture was taken with config/default, acquire 10M, method:peak, probe X1, horz=100us
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In your one image where probe is directly connected to probe comp output.
This kind of noise is not normal. And it is in this signal low level part as much as signal top level part.
Where from it come, it need find. Is it from inside or outside?
It is pity you can not get trusted lower level signal with known low noise level.
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I think it is coming from the scope itself. Something in the signal path does this.
I have contacted the supplier, and they said it has a 3 year warranty, and that they will send me instructions of how to get it repaired.
So I am waiting...
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Actually, could you please perform the same test as I did and post your picture? You only need 2 resistors, a 10K and a 470R.
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I think it is coming from the scope itself. Something in the signal path does this.
I have contacted the supplier, and they said it has a 3 year warranty, and that they will send me instructions of how to get it repaired.
So I am waiting...
Yes, this can suspect. But proofing it is other game. ;)
Also there is only small signs but 1kHz rise and fall can not normally detect from open inputs captured noise. But you have these and clearly.
Picture A.
10k + 500ohm
Probe 1x (forget to change scope probe set to 1x so it is there 10x)
Enviroment not very clean but reasonable.
Picture B
Exactly all same. Added 137MHz RF field (clean quite stable 3W output to bad small pen style antenna and antenna around over 3meter away from scope.. (I do not know anything how this small around 15cm antenna radiate around, I have here not available now field strenght measurement)
Note also that probe itself is low pass filter when it is 1:1 mode.
AND note also: Oscilloscope have (partially) loosed trig to this 1kHz square! It "looks like" it trigs randomly rising or falling edge but not full random related to 1kHz becouse this RF disturb trigger circuit.
This is only imagine that many kind of noise can affect very easy. Probe tip is 500ohm from GND. Probe BW is around 6MHz But it is still nice antenna.
This give only some idea that always is good to suspect everything and then step by steb close different things out and finally it know - if know.
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NOTE: PLEASE READ:
It has been bought to my attention that users "aghp" and "rf-loop" who have been posting to this thread (and others) are in fact the same person. They have posted under identical IP address at various times, but generally have tried to avoid doing that by using different IP's for the two accounts.
Given that "aghp" is a dealer, then this is potentially unethical (I have not read all thread/posts to see what has been said by either though). aghp's account has thus been suspended.
Given rf-loops good technical content, he is welcome to continue to contribute to the forum under the "rf-loop" handle, subject to the usual rules.
Perhaps he'd like to explain?
Dave.
-
Note that due to shortage of IP4 adresses providers (especially the ones offering internet access through 'GSM' networks) use NAT to share a few IP addresses between a lot of users. In other words: nowadays you can't identify users strictly by their IP address.
-
Note that due to shortage of IP4 adresses providers (especially the ones offering internet access through 'GSM' networks) use NAT to share a few IP addresses between a lot of users. In other words: nowadays you can't identify users strictly by their IP address.
Be that as it may, what Dave posted is true - as some here have known for awhile.
-
Note that due to shortage of IP4 adresses providers (especially the ones offering internet access through 'GSM' networks) use NAT to share a few IP addresses between a lot of users. In other words: nowadays you can't identify users strictly by their IP address.
There are others things that point to it too, not just IP. But even if you just had the IP, two people with the same IP, posting in the same forum, on the same topic, with the same passion, with the same technical knowledge?
Calculate the odds.
rf-roop is aghp
If he's not, he'd be right back here explaining how we got it all wrong...
Dave.
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I am not sure what the benefit of having two accounts might be, however aghp has been helpful to me recently regarding my problems with a defective Owon scope.
-
There are others things that point to it too, not just IP. But even if you just had the IP, two people with the same IP, posting in the same forum, on the same topic, with the same passion, with the same technical knowledge?
Calculate the odds.
rf-roop is aghp
If he's not, he'd be right back here explaining how we got it all wrong...
Dave.
I have known that since I joined here (worked it out while reading ALL of this thread ;) ) and didn't point it out because I thought it was some kind of allowed arrangement. One never quoted the other, bu they both talked in the same way and misspelled the same words.
Still, there is no denying that he has contributed significantly and positively to this thread.
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There are others things that point to it too, not just IP. But even if you just had the IP, two people with the same IP, posting in the same forum, on the same topic, with the same passion, with the same technical knowledge?
Calculate the odds.
rf-roop is aghp
If he's not, he'd be right back here explaining how we got it all wrong...
Dave.
could be 2 people working in the same business, hence the same internet connection (and possibly even the same computer) and same knowledge etc...
;)
but the odds are they are probably the same person.
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Quite funnily, I have suspected this for a while due to the language they used, e.g. what is the possibility that two independent persons both spell "again" as "agen". Take a look at the posts. I have heard lot of good things from aghp/rf-loop and have absolutely nothing against him, but just wondering why use two accounts?
Regards,
Janne
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Well I bought my scope from Amazon, UK, from a company that purports to import them to the UK. So I paid 100 pounds extra compared to ebay, but at least I thought I was buying from the UK, so avoid all hassle with customs etc.
The scope took many weeks to arrive, so obviously it came straight from China. Additionally now that it is broken, I have been exchanging emails with the UK company, who appear to be signing their emails with a US new jersey address, and they have been asking me dozens of questions like "did you earth the probes?" "did you try both channels" "did you try alternative probes" and all that cr*p. My first email to them I believe was December 28, and as yet I have not received solid instructions on how they propose to repair it or replace it.
Crossing fingers they will honour their 3 year warranty.
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Well I bought my scope from Amazon, UK, from a company that purports to import them to the UK. So I paid 100 pounds extra compared to ebay, but at least I thought I was buying from the UK, so avoid all hassle with customs etc.
The scope took many weeks to arrive, so obviously it came straight from China. Additionally now that it is broken, I have been exchanging emails with the UK company, who appear to be signing their emails with a US new jersey address, and they have been asking me dozens of questions like "did you earth the probes?" "did you try both channels" "did you try alternative probes" and all that cr*p. My first email to them I believe was December 28, and as yet I have not received solid instructions on how they propose to repair it or replace it.
Crossing fingers they will honour their 3 year warranty.
Please do you have 1 pcs 50ohm bnc terminators?
If you have:
Default scope.
Set oscilloscope menu probe setting to 1x for both channel.
Turn both channels to 5mV/div
1ms/div speed.
Turn memory to 1M
Turn acquire to Peak mode!
In all cases keep both traces visible.
1.
Connect one BNC terminator to ONLY CH1 but so that its center pin do not make contact (you pull and push you look trace you find where it connect and where not.
Take TFT image to usb or computer.
Push terminator fully in (it make connect) and take image agen.
(in both images keep CH2 just open)
2.
Connect one BNC terminator to ONLY CH2 but so that its center pin do not make contact (you pull and push you look trace you find where it connect and where not.
Take TFT image to usb or computer.
Push terminator fully in (it make connect) and take image agen.
(in both images keep CH1 just open)
Show these 4 images.
If I try help you for arrange RMA with Owon I need know real data what show to me that it is broken. It seems that your seller is just in class "we sell nice boxes but we do not know what they are"
Opinion is not enough in this case - it need data. (I do not want burn my fingers with Owon (becouse I need use "kitchen door" for help others than my customers) if later there find that reason for noise is example some (very bad and strange) electromagnetic noise in your enviroment. I do not try tell that it is my suspect - only I want close this small posibility out first)
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Hey guys! I just wanted to ask: Did it happen to any of you that you press the power button on the scope and nothing happens?
Usually as soon as I press the top power button the screen turns on and I hear fan working, but sometimes even after several tens of seconds, nothing happens. If I turn it off and on again, it always starts fine.
Oh, and since nobody mentioned it, it seems that in the new 2.8.2 firmware, there's a trigger frequency counter for both channels available. Previously one one would be visible in ALT mode.
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Hey guys! I just wanted to ask: Did it happen to any of you that you press the power button on the scope and nothing happens?
Usually as soon as I press the top power button the screen turns on and I hear fan working, but sometimes even after several tens of seconds, nothing happens. If I turn it off and on again, it always starts fine.
Oh, and since nobody mentioned it, it seems that in the new 2.8.2 firmware, there's a trigger frequency counter for both channels available. Previously one one would be visible in ALT mode.
Yes I have seen failed power supply.
Look front panel power led first after you connect power cable and sidepanel primary switch on.
Then how it light when you push power switch on (top of scope).
What is your scope original displayed version and serial number. (no need last three digits).
In ALT mode both channels have own separately settable trig and it also show both channels trig frequency. This function have been as long as I remember.
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Interesting! I must have missed the frequency somehow in ALT mode before.
The original version was 2.6.2, if I remember correctly. Serial number is SDS71021211xxx
I have the version with the battery. When I first turn the power on on the side switch, the LED is orange for a while and then turns green with the battery installed. Without the battery, it turns green immediately.
Right now my battery is discharged, so when I press the power button with the side power on, the LED changes color from orange. I'm not sure how to exactly describe it, but it seems to be redder than when the scope's main power button is off. After some time, it turns green.
When the "problem" occurs, the LED stays off, like everything else.
I'm sorry for providing incorrect information. The LED is green. If it was orange before turning on, it turns green.
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When the "problem" occurs, the LED stays off, like everything else.
Take battery out.
Use it some time without battery and note if you find this same situation where power led stay off after power plug is connected and sidepanel switch ON.
Have it never shut off itself? (exept battery discharged)
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No, it never turned itself off. I never did run the battery past the low capacity warning, so it never turned off due to discharged battery. I'll let it run without the battery for a while and report what happens.
The problem usually occurs when the scope wasn't used for a while, so it may take some time for me to determine if the problem disappeared.
Also thanks for help.
UPDATE: It happened again without the battery.
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I recently purchased a SDS7102 and have similar noise issues as user akis is experiencing. As far as I can tell, the noise is being generated by the scope itself and seems to be somewhat broadband in nature, running from around 80 - 100 MHz. It is NOT in the actual signal path (for me at least), since it can be eliminated when I use straight coaxial cables instead of probes or jumpers. I also know it is not environmental as I can pick it up on my Tek DPO, but only when the Owon is powered on. Happy to run any tests or post pictures to better explain this. My serial is SDS71021246xxx and it is running 2.8.2 firmware.
I am assuming I have a bad unit with some type of shielding / grounding problem, because the level of noise being generated is far from subtle and should have been easily picked up during product EMI testing.
--Bill
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i'm looking for someone, with signal gen, to run some frequency response tests on the Owon SDS series:
https://www.eevblog.com/forum/reviews/frequency-response-of-your-dso/ (https://www.eevblog.com/forum/reviews/frequency-response-of-your-dso/)
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i'm looking for someone, with signal gen, to run some frequency response tests on the Owon SDS series:
https://www.eevblog.com/forum/reviews/frequency-response-of-your-dso/ (https://www.eevblog.com/forum/reviews/frequency-response-of-your-dso/)
Here is some but later after I have time I can run better... (http://owon.forumup.com/viewtopic.php?t=137&mforum=owon)
I have not system where I can measure direct level from scope BNC for keep this level flatness inside some acceptable tolerances.
But I have power meter and I can look my signal generator output signal flatness directly to power head. It do not tell "anything" what is level in scope BNC after it is connected there. (it is not 50ohm impedance over example 0-500MHz due to oscilloscope input reactance.)
It can perhaps littlebit help with attenuator but.. then can not measure other than only lowest (direct) voltage band.
But still it can do measurement and it is better than nothing.
I can use HP8644B what is enough accurate for this measurement.
But now some days busy with other things.
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I've used calibrated R&S SMX which is specified as < 1.5dBm over full range, however i know in the range i've used it's ±0.25dBm, which is more tha good enough. HP8644B is for sure good enough, it's < 1dBm (and typical i think less than ±0.5dBm) over full range - which we don't need it anyway.
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Well I bought my scope from Amazon, UK, from a company that purports to import them to the UK. So I paid 100 pounds extra compared to ebay, but at least I thought I was buying from the UK, so avoid all hassle with customs etc.
The scope took many weeks to arrive, so obviously it came straight from China. Additionally now that it is broken, I have been exchanging emails with the UK company, who appear to be signing their emails with a US new jersey address, and they have been asking me dozens of questions like "did you earth the probes?" "did you try both channels" "did you try alternative probes" and all that cr*p. My first email to them I believe was December 28, and as yet I have not received solid instructions on how they propose to repair it or replace it.
Crossing fingers they will honour their 3 year warranty.
Please do you have 1 pcs 50ohm bnc terminators?
If you have:
Default scope.
Set oscilloscope menu probe setting to 1x for both channel.
Turn both channels to 5mV/div
1ms/div speed.
Turn memory to 1M
Turn acquire to Peak mode!
In all cases keep both traces visible.
1.
Connect one BNC terminator to ONLY CH1 but so that its center pin do not make contact (you pull and push you look trace you find where it connect and where not.
Take TFT image to usb or computer.
Push terminator fully in (it make connect) and take image agen.
(in both images keep CH2 just open)
2.
Connect one BNC terminator to ONLY CH2 but so that its center pin do not make contact (you pull and push you look trace you find where it connect and where not.
Take TFT image to usb or computer.
Push terminator fully in (it make connect) and take image agen.
(in both images keep CH1 just open)
Show these 4 images.
If I try help you for arrange RMA with Owon I need know real data what show to me that it is broken. It seems that your seller is just in class "we sell nice boxes but we do not know what they are"
Opinion is not enough in this case - it need data. (I do not want burn my fingers with Owon (becouse I need use "kitchen door" for help others than my customers) if later there find that reason for noise is example some (very bad and strange) electromagnetic noise in your enviroment. I do not try tell that it is my suspect - only I want close this small posibility out first)
I have bought two brand new BNC terminators 50R and tried them. There is absolutely no difference between "fully inserted plug" or "just touching". I attach a picture which should count for all the four that you have asked me.
The Owon people have come back to me and told me not to expect too much from the scope as it is a cheap scope. However I genuinely think mine is broken as there is all this noise which renders the scope almost useless for signals below 100mV RMS or thereabouts.
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The Owon people have come back to me and told me not to expect too much from the scope as it is a cheap scope. However I genuinely think mine is broken as there is all this noise which renders the scope almost useless for signals below 100mV RMS or thereabouts.
akis -- I believe my scope is having the same noise issues as yours and I find it hard to believe (as do you) that Owon would classify this as acceptable performance. I am attaching screen shoots. The first two are of my SDS7102 and Tek DPO20204 attached to the same signal generator using their supplied probes. The Tek is being triggered off of the Owon's trigger out since the noise seems to be synchronized with the Owon's sweeps and this allows it to be better captured visually. The next is of the Tek connected to the same signal generator, but with the Owon turned off and it triggered internally. The last is of the Owon connected to the signal generator using a coaxial cable and a 50 Ohm straight through terminator.
Comments anyone?
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The first two are of my SDS7102 and Tek DPO20204 attached to the same signal generator using their supplied probes.
with probes directly to signal gen output, right?
The Tek is being triggered off of the Owon's trigger out since the noise seems to be synchronized with the Owon's sweeps and this allows it to be better captured visually.
ok, and how it looks when Tek is using own trigger and Owon is on? Is Tek having then clean picture and Owon noisy one?
The next is of the Tek connected to the same signal generator, but with the Owon turned off and it triggered internally. The last is of the Owon connected to the signal generator using a coaxial cable and a 50 Ohm straight through terminator.
so here im principe both connected directly t signal gen and triggering with own internal trigger, they looks ok, but for sure coax cable is part of the answer here.
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with probes directly to signal gen output, right?
Yes -- directly connected using the pincher and ground lead clipped onto a BNC to banana adapter that is attached to the signal generator through a 50 Ohm passthrough terminator.
ok, and how it looks when Tek is using own trigger and Owon is on? Is Tek having then clean picture and Owon noisy one?
It is just as noisy, but the noise is "free running" so it gets somewhat washed out by the Tek's DPO processor.
so here im principe both connected directly to signal gen and triggering with own internal trigger, they looks ok, but for sure coax cable is part of the answer here.
Yes -- when either scope is directly connected it is fully shielded and the noise level drops significantly. Forgot to mention that I placed a 10x attenuator in line on the cable so the amplitude would match the 10x probe. As posted earlier, the noise seems to be comprised of 70 - 100 MHz bursts that are in sync with the Owon's sweep.
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I have bought two brand new BNC terminators 50R and tried them. There is absolutely no difference between "fully inserted plug" or "just touching". I attach a picture which should count for all the four that you have asked me.
This your image looks ok. (It is nice if someone with example Tektronix do same. 1ms/div, 5mV/div, peak mode.)
It was important to find that 50ohm terminator fully in and "open but shield" make no difference. It was 2011 when there was manufacturing mistake and it make CH1 very noisy and there can see big difference if terminated or open. Shielding is important for block noise what is coming outside)
This peak - peak noise you show in this image is good if you compare for what ever this class of scope. You can also find some tables where this noise is littlebit compared to some others.
Scope analog front end noise level looks ok.
The Owon people have come back to me and told me not to expect too much from the scope as it is a cheap scope. However I genuinely think mine is broken as there is all this noise which renders the scope almost useless for signals below 100mV RMS or thereabouts.
This need investigate more.
(I have some suspects and there may be something....)
But it is clear that if signal what oscilloscope see in its BNC input do not have noise also oscilloscope do not internally add this noise to signal.
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But it is clear that if signal what oscilloscope see in its BNC input do not have noise also oscilloscope do not internally add this noise to signal.
In my "uneducated" view, the scope is useless for observing signals below a certain amplitude. The 20MHz internal filter makes things a bit better in these cases, but then you have a 20MHz (or less) scope, not a 100MHz scope, and it is still not clear enough for it to even lock on.
My old, 30+ year old, 20MHz scope displays the same curves with no problems.
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My old, 30+ year old, 20MHz scope displays the same curves with no problems.
This is fun. But very very common wondering. Why my digital oscilloscope is so noisy if I compare it to my old conventional oscilloscope and what best.. 20Mhz oscilloscope. Try look 10ns pulse with it, say example it occurs 10 times per second. How about 100ns pulse what occurs example on time per second. You see something? Try same with digital oscilloscope. Why? What filters it out... and I can tell... it filters also noise by same way.
You can easu find example some Tektronix paper about this.
Then here more about Owon tests related to noise. Look also last table. (http://owon.forumup.com/viewtopic.php?t=137&mforum=owon)
In this thread was bill2010 images with Owon and Tek
here in same scale (yes of course Tek is much more expensive, totally different class of tool. Also it have more BW but here sampling rate same and same horz speed and same vertical. Owon BW is around over 150MHz and Tek is "rated" as 200MHz but not know what is real BW.. perhaps lot of over 200MHz but it do not explain this noise... but also it need remember that in this picture Tek have collected lot of more data... if Owon is long time with infinite persistence it may change this situation some amount.. )
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Here are some more pictures to demonstrate the problem. Scope was away from any sources of interference and not connected to the mains.
The signal is 120mV pk-pk at 1KHz. This is not a "small" signal. I repeat : it is 120mV pk-pk.
The situation gets worse, much worse, as the signal gets weaker. I even wonder why bother have a "5mV" or a "10mV" scale when in reality they are so useless. Also the only way to get a clear picture is to "limit" the scope to 20MHz, in which case why advertise it as a "100MHz".
Picture 1 shows the amount of random noise :
Picture 2 shows the same but with the scope set to 20MHz.
Picture 3 shows the same but with the addition of "sample" rather than "peak". Had I put the screen persistence on (like old phosphor displays) it would also be much worse.
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I'm looking to buy a owon sds7102 sometime within the next week or so, and was wondering, what is the newest firmware for it. It will hopefully be the version with vga and ethernet port. I also hope to obtain a battery for it as well. dont know what serial number I will be getting till it gets here.
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Here are some more pictures to demonstrate the problem. Scope was away from any sources of interference and not connected to the mains.
The signal is 120mV pk-pk at 1KHz. This is not a "small" signal. I repeat : it is 120mV pk-pk.
The situation gets worse, much worse, as the signal gets weaker. I even wonder why bother have a "5mV" or a "10mV" scale when in reality they are so useless. Also the only way to get a clear picture is to "limit" the scope to 20MHz, in which case why advertise it as a "100MHz".
Picture 1 shows the amount of random noise :
Picture 2 shows the same but with the scope set to 20MHz.
Picture 3 shows the same but with the addition of "sample" rather than "peak". Had I put the screen persistence on (like old phosphor displays) it would also be much worse.
There is something wrong.
Here some images.
Now here used Owon probe what is connected to 50ohm terminated signal generators output. (50ohm source need 50ohm termination for correct level.)
All shots are real time single captures and of course without averaging. Normal acquire.
for 300kHz used HP8644B signal generator (it have very clean signal)
for 1kHz used HP3314A "noise gener....oops... function generator"
Owon used for test:
SDS7102V series: 1246xxx
Version 2.8.2
Probe: "T5100" (Oscilloscope normal accessory)
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Therefore I will email the company I bought it from and ask them to replace it, obviously the scope is capable of better quality, I must have been given a bad one.
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Here are some more pictures to demonstrate the problem. Scope was away from any sources of interference and not connected to the mains.
The signal is 120mV pk-pk at 1KHz. This is not a "small" signal. I repeat : it is 120mV pk-pk.
The situation gets worse, much worse, as the signal gets weaker. I even wonder why bother have a "5mV" or a "10mV" scale when in reality they are so useless. Also the only way to get a clear picture is to "limit" the scope to 20MHz, in which case why advertise it as a "100MHz".
Picture 1 shows the amount of random noise :
Picture 2 shows the same but with the scope set to 20MHz.
Picture 3 shows the same but with the addition of "sample" rather than "peak". Had I put the screen persistence on (like old phosphor displays) it would also be much worse.
There is something wrong.
Here some images.
Now here used Owon probe what is connected to 50ohm terminated signal generators output. (50ohm source need 50ohm termination for correct level.)
All shots are real time single captures and of course without averaging. Normal acquire.
for 300kHz used HP8644B signal generator (it have very clean signal)
for 1kHz used HP3314A "noise gener....oops... function generator"
Owon used for test:
SDS7102V series: 1246xxx
Version 2.8.2
Probe: "T5100" (Oscilloscope normal accessory)
Here is a screen capture from mine mirroring the setup you used for your first picture. My signal generator isn't as clean as the HP, but I've verified the output on my Tek DPO (with the Owon turned off) and it is much cleaner then the signal the Owon is seeing. Serial 71021246xxx, firmware 2.8.2. Other than this noise problem, I really like the scope.
Looks like mine is heading back as well...
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Here are some more pictures to demonstrate the problem. Scope was away from any sources of interference and not connected to the mains.
The signal is 120mV pk-pk at 1KHz. This is not a "small" signal. I repeat : it is 120mV pk-pk.
The situation gets worse, much worse, as the signal gets weaker. I even wonder why bother have a "5mV" or a "10mV" scale when in reality they are so useless. Also the only way to get a clear picture is to "limit" the scope to 20MHz, in which case why advertise it as a "100MHz".
Picture 1 shows the amount of random noise :
Picture 2 shows the same but with the scope set to 20MHz.
Picture 3 shows the same but with the addition of "sample" rather than "peak". Had I put the screen persistence on (like old phosphor displays) it would also be much worse.
Did you use the supplied probes to connect to the signal source in picture 1? If so, was the probe set to 10x or 1x? I am trying to reproduce on my own SDS7102 as I believe that mine has a similar defect. Do you have a coaxial cable you can use? On mine, the noise seems to be external (but generated by the Owon itself) to the actual signal path as it is greatly attenuated when using a fully shielded connection between the scope and the signal generator.
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Here are some more pictures to demonstrate the problem. Scope was away from any sources of interference and not connected to the mains.
The signal is 120mV pk-pk at 1KHz. This is not a "small" signal. I repeat : it is 120mV pk-pk.
The situation gets worse, much worse, as the signal gets weaker. I even wonder why bother have a "5mV" or a "10mV" scale when in reality they are so useless. Also the only way to get a clear picture is to "limit" the scope to 20MHz, in which case why advertise it as a "100MHz".
Picture 1 shows the amount of random noise :
Picture 2 shows the same but with the scope set to 20MHz.
Picture 3 shows the same but with the addition of "sample" rather than "peak". Had I put the screen persistence on (like old phosphor displays) it would also be much worse.
Did you use the supplied probes to connect to the signal source in picture 1? If so, was the probe set to 10x or 1x? I am trying to reproduce on my own SDS7102 as I believe that mine has a similar defect. Do you have a coaxial cable you can use? On mine, the noise seems to be external (but generated by the Owon itself) to the actual signal path as it is greatly attenuated when using a fully shielded connection between the scope and the signal generator.
Yes, I used the supplied probes for this test. Set to 1X. Source resistance about 600R. Signal 120mV pk-pk.
I forgot to say, the ONLY way to get a steady curve, is with trigger set to "HF". If you are looking at DC forget it.
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Here are some more pictures to demonstrate the problem. Scope was away from any sources of interference and not connected to the mains.
The signal is 120mV pk-pk at 1KHz. This is not a "small" signal. I repeat : it is 120mV pk-pk.
The situation gets worse, much worse, as the signal gets weaker. I even wonder why bother have a "5mV" or a "10mV" scale when in reality they are so useless. Also the only way to get a clear picture is to "limit" the scope to 20MHz, in which case why advertise it as a "100MHz".
Picture 1 shows the amount of random noise :
Picture 2 shows the same but with the scope set to 20MHz.
Picture 3 shows the same but with the addition of "sample" rather than "peak". Had I put the screen persistence on (like old phosphor displays) it would also be much worse.
Did you use the supplied probes to connect to the signal source in picture 1? If so, was the probe set to 10x or 1x? I am trying to reproduce on my own SDS7102 as I believe that mine has a similar defect. Do you have a coaxial cable you can use? On mine, the noise seems to be external (but generated by the Owon itself) to the actual signal path as it is greatly attenuated when using a fully shielded connection between the scope and the signal generator.
Yes, I used the supplied probes for this test. Set to 1X. Source resistance about 600R. Signal 120mV pk-pk.
I forgot to say, the ONLY way to get a steady curve, is with trigger set to "HF". If you are looking at DC forget it.
Replicated your setup. 1 KHz sine wave @ 120 mV pk-pk feed into channel 1 through the probe set on 1x. Peak mode, full bandwidth. Looks similar, but yours seem to have even more noise. Output impedance of my signal source is 50 Ohms, so that may account for some of the difference. I've contacted my distributor for a replacement as well.
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@firehopper
Newest firmware is 2.8.2 and as far as I can see, newest hardware revision is also 2.8.2. Do read the resources rf-loop posts on his forum. They're good if you want to be up to date.
There's is no need to hope for VGA out or not. The version with VGA out is called SDS7102V and is a bit more expensive than the version without. From what I've seen (but I could be wrong), in some markets, the available version is with V and in some is without V. In some markets, both versions are available, so check which version exactly you're getting.
As far as I can see, all scopes from 2012 have Ethernet.
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As far as I can see, all scopes from 2012 have Ethernet.
Ethernet (LAN) Yes, today it is factory default.
More than one year ago it was factory option.
VGA is factory option (need buy from factory with extra charge). If scope have V it have VGA.
(SDS8302 and 9302 have VGA + LAN as factory default without letter V.)
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Other:
This suspected noise problem in some units need study more.
It looks like if it come from oscilloscope it do not pollute internally signal pathway. But if there is strong noise generated by oscilloscope itself it may connect externally to signal.
Later I will take one oscilloscope open and do some tests.
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Other:
This suspected noise problem in some units need study more.
It looks like if it come from oscilloscope it do not pollute internally signal pathway. But if there is strong noise generated by oscilloscope itself it may connect externally to signal.
Later I will take one oscilloscope open and do some tests.
My testing definitely seems to indicate that it is generated by the oscilloscope, but does not pollute the internal signal path. The noise appears to be somewhat broadband in nature ranging from around 70 - 100 MHz, which explains why when you apply the 20 MHz bandwidth limiter it reduces it. It almost looks like some kind of ringing. You can see this in the attached, with the greatest amplitude right at the trigger point. If you speed up the sweep it is very visible. Will try to post another picture showing this later.
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My testing definitely seems to indicate that it is generated by the oscilloscope, but does not pollute the internal signal path. The noise appears to be somewhat broadband in nature ranging from around 70 - 100 MHz, which explains why when you apply the 20 MHz bandwidth limiter it reduces it. It almost looks like some kind of ringing.
Yes I know this. Of course fast rising/falling edge include lot of frequency components.
Also there may be internal ringing due to these fast edges.
Your message Reply #880 at 10:20:51 AM
And there image: 20130130_264121.bmp
It tells to me "lot of" things.
Now is time to do lab work for this. I will dismantle one SDS and look more deep things related to this.
Information of a potential problem now is enough here. Now need starting study. What is needed now is only to work in peace and arrange time slot for do it. I will also contact with Owon after I have more than suspects and nearly empty hand. (I have a couple of suspects, it should be examined.)
It is fully possible there is only some units if problem is example in some circuits for filtering these switch mode noise... perhaps lack of some component or "whatever"...
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My testing definitely seems to indicate that it is generated by the oscilloscope, but does not pollute the internal signal path. The noise appears to be somewhat broadband in nature ranging from around 70 - 100 MHz, which explains why when you apply the 20 MHz bandwidth limiter it reduces it. It almost looks like some kind of ringing.
Yes I know this. Of course fast rising/falling edge include lot of frequency components.
Also there may be internal ringing due to these fast edges.
Your message Reply #880 at 10:20:51 AM
And there image: 20130130_264121.bmp
It tells to me "lot of" things.
Now is time to do lab work for this. I will dismantle one SDS and look more deep things related to this.
Information of a potential problem now is enough here. Now need starting study. What is needed now is only to work in peace and arrange time slot for do it. I will also contact with Owon after I have more than suspects and nearly empty hand. (I have a couple of suspects, it should be examined.)
It is fully possible there is only some units if problem is example in some circuits for filtering these switch mode noise... perhaps lack of some component or "whatever"...
What is your hunch? Is it maybe a manufacturing line problem (eg dirt on the tracks), a failing component, or a flaw in the design ?
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What is your hunch? Is it maybe a manufacturing line problem (eg dirt on the tracks), a failing component, or a flaw in the design ?
Now is the time to examine first, not tell the dozens of statements about what I believe or suspect. I will report back once I know something concrete. The study first, and then the speech is the wiser.
But it takes now some time.
Also soon now in China is starting "new year" time and it make lot of delays in communication with Owon.
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My testing definitely seems to indicate that it is generated by the oscilloscope, but does not pollute the internal signal path. The noise appears to be somewhat broadband in nature ranging from around 70 - 100 MHz, which explains why when you apply the 20 MHz bandwidth limiter it reduces it. It almost looks like some kind of ringing.
Yes I know this. Of course fast rising/falling edge include lot of frequency components.
Also there may be internal ringing due to these fast edges.
Your message Reply #880 at 10:20:51 AM
And there image: 20130130_264121.bmp
It tells to me "lot of" things.
Now is time to do lab work for this. I will dismantle one SDS and look more deep things related to this.
Information of a potential problem now is enough here. Now need starting study. What is needed now is only to work in peace and arrange time slot for do it. I will also contact with Owon after I have more than suspects and nearly empty hand. (I have a couple of suspects, it should be examined.)
It is fully possible there is only some units if problem is example in some circuits for filtering these switch mode noise... perhaps lack of some component or "whatever"...
What is your hunch? Is it maybe a manufacturing line problem (eg dirt on the tracks), a failing component, or a flaw in the design ?
akis, rf-loop -- my supplier pulled another scope from stock and was able to reproduce the noise problem, so it appears that this affecting more than just a few units. Hopefully we can get a fix from Owon (perhaps through rf-loop's investigations), since the only alternative seems to be to return the unit for a refund. That would be a real shame as it is hard to find a portable unit with similar specifications that is even close to the price of the SDS7102.
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My testing definitely seems to indicate that it is generated by the oscilloscope, but does not pollute the internal signal path. The noise appears to be somewhat broadband in nature ranging from around 70 - 100 MHz, which explains why when you apply the 20 MHz bandwidth limiter it reduces it. It almost looks like some kind of ringing.
Yes I know this. Of course fast rising/falling edge include lot of frequency components.
Also there may be internal ringing due to these fast edges.
Your message Reply #880 at 10:20:51 AM
And there image: 20130130_264121.bmp
It tells to me "lot of" things.
Now is time to do lab work for this. I will dismantle one SDS and look more deep things related to this.
Information of a potential problem now is enough here. Now need starting study. What is needed now is only to work in peace and arrange time slot for do it. I will also contact with Owon after I have more than suspects and nearly empty hand. (I have a couple of suspects, it should be examined.)
It is fully possible there is only some units if problem is example in some circuits for filtering these switch mode noise... perhaps lack of some component or "whatever"...
What is your hunch? Is it maybe a manufacturing line problem (eg dirt on the tracks), a failing component, or a flaw in the design ?
akis, rf-loop -- my supplier pulled another scope from stock and was able to reproduce the noise problem, so it appears that this affecting more than just a few units. Hopefully we can get a fix from Owon (perhaps through rf-loop's investigations), since the only alternative seems to be to return the unit for a refund. That would be a real shame as it is hard to find a portable unit with similar specifications that is even close to the price of the SDS7102.
Ha HA Ha HA , that was funny! .
And even more so in brackets after :-DD
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Well now, you can add me to the list of 'noisy' scopes. Can anyone comment on the warranty service from Owon as of late? Best avenue of approach?
I have to say that for what it offered at the price point it offered, it's been an ok little device but this is an unreasonable defect that seems to be occurring to more than a few owners of the scope. I knew of its limitations when I purchased it and they were acceptable for what I paid/expected but one would expect for hardware to last a bit longer than this.
I'm cringing just thinking about what its going to be like getting a repair/replacement. I would even be willing to do the repair myself if they've already identified the problem and want to pass along the information/parts (obviously not going to happen - just part of my rant). |O
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My testing definitely seems to indicate that it is generated by the oscilloscope, but does not pollute the internal signal path. The noise appears to be somewhat broadband in nature ranging from around 70 - 100 MHz, which explains why when you apply the 20 MHz bandwidth limiter it reduces it. It almost looks like some kind of ringing.
Yes I know this. Of course fast rising/falling edge include lot of frequency components.
Also there may be internal ringing due to these fast edges.
Your message Reply #880 at 10:20:51 AM
And there image: 20130130_264121.bmp
It tells to me "lot of" things.
Now is time to do lab work for this. I will dismantle one SDS and look more deep things related to this.
Information of a potential problem now is enough here. Now need starting study. What is needed now is only to work in peace and arrange time slot for do it. I will also contact with Owon after I have more than suspects and nearly empty hand. (I have a couple of suspects, it should be examined.)
It is fully possible there is only some units if problem is example in some circuits for filtering these switch mode noise... perhaps lack of some component or "whatever"...
What is your hunch? Is it maybe a manufacturing line problem (eg dirt on the tracks), a failing component, or a flaw in the design ?
akis, rf-loop -- my supplier pulled another scope from stock and was able to reproduce the noise problem, so it appears that this affecting more than just a few units. Hopefully we can get a fix from Owon (perhaps through rf-loop's investigations), since the only alternative seems to be to return the unit for a refund. That would be a real shame as it is hard to find a portable unit with similar specifications that is even close to the price of the SDS7102.
Ha HA Ha HA , that was funny! .
And even more so in brackets after :-DD
Well, Owon did produce a fix for the channel 1 noise issue that cropped up after a hardware change and rf-loop seems like a fairly knowledgeable guy who had the added incentive as a distributor to want his products to be competitive, so this statement didn't seem like nearly enough of a stretch for someone to be LOL over it...
Regardless, I bought the scope as an "experiment" given the cost and I am seriously thinking of just debugging and fixing it myself vs. returning it for a refund. If it was a signal path issue I'd be more skeptical, but it looks like more of a general shielding / bypass problem which should be far easier to solve.
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Here two images. (http://owon.forumup.com/about154-owon.html)
This new power supply in picture have also SMD components on the solder side (not in picture)
These both need now more deep investigations.
(these have lot of small changes after older (many) versions.
PCB layout, routing and some componets are changed.
They have try do it better - but something is now wrong in my opinion.
It is even possible that secret is in some components specifications.
Parasitic osc......
EDIT/ADD:
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Owon have holiday 7th to 17th Feb due to Spring Festiwal time.
(whole China is more or less on the holiday) and after holiday, no one know who workers return back (hehe) from holiday and so or so but after holiday all services are heavy loaded, rush and queyed....
Disclaimer: This next all is now my unofficial opinion!
After some talking with Owon about some findings (in scope internals) I believe there is coming some, perhaps very simple, solution but not just immediately. There is not just one problem... it is perhaps group of problems perhaps related to some components parameters and perhaps also PCB design (This power supply and adapter card is very new version if looks also used components) With very fast rising edges there need handle tens and hudreds of megaherz freq components in single simple 50kHz switch mode regulator. Now something have changed and...
This is only example, NOT related to this case.
I remember once in history some fun (and expensive)... there was one case... all works in lab very nice... in proto.
One proto PCB inductor was take from "lab test and evaluating component box" but it have wanted inductance etc.. all was fully tested and exactly ok.
Then later someone buy these "looks like" inductors, same inductance and so on...
All was then wrong... extreme heat... components burn... it was like spread spectrum VHF transmitter for EW... one simple power supply.
Before solution and repair it need take extreme care about probing methods so that this partially common mode noise do not pollute signal under test or it do not disturb device under test. Inside scope it do not (significantly) pollute internal signal pathway from BNC input to ADC.
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Also note: If you have OLD version service manual or other OLD material how to open oscilloscope.
It have changed. If you try pull power button out before opening case... DO NOT. It do not come out without damage.
Push it fully inside same time carefully opening bac cover.
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Owon have holiday 7th to 17th Feb due to Spring Festiwal time.
(whole China is more or less on the holiday) and after holiday, no one know who workers return back (hehe) from holiday and so or so but after holiday all services are heavy loaded, rush and queyed....
Disclaimer: This next all is now my unofficial opinion!
After some talking with Owon about some findings (in scope internals) I believe there is coming some, perhaps very simple, solution but not just immediately. There is not just one problem... it is perhaps group of problems perhaps related to some components parameters and perhaps also PCB design (This power supply and adapter card is very new version if looks also used components) With very fast rising edges there need handle tens and hudreds of megaherz freq components in single simple 50kHz switch mode regulator. Now something have changed and...
Thanks for putting some time in on this and working with your contacts at Owon. Seems like a reasonable line of thinking to explore. One thing I should add is that the noise is the same when running off the line or battery, so it would have to be related to the power supply components that are common to both modes of operation.
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Yes the problem is present with running on batteries therefore the PSU/rectifier/transformer etc should be excluded.
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Yes the problem is present with running on batteries therefore the PSU/rectifier/transformer etc should be excluded.
There are LOT of switch mode regulators inside oscilloscope.
With battery alone used for power there is only one what is not working.
There is two sources for raw 8.4V "main" power. Battery or external 110-240V.
After this there is lot of switch mode power supplies/regulators. Also in power supply module there need also do negative (-7.5V).
Power supply unit produce only raw 8.4V and -7.5V voltages. These are not (in mainstream) used directly but they are used for sub power supplies / regulators around of oscilloscope.
Some of these switch mode circuits produce now high amount of parasitic oscillations/ringing. (Why? Perhaps some components more deep parameters... all know that inductor is example 8.8uH but there is also many other things.. core material, internal parasitic capasitances...etc.. Also perhaps layout changes may have some role.
This whole case need more deep investigation.
Good thing is: These "noises" do NOT pollute signal pathways inside oscilloscope!
My recommendation for users and specailly now before this is solved:
take special care about probing!
We know now that clean signal example via well shielded and matched coaxial and there can not see any sign of this problem.
And nearly as good situation is with oscilloscope probe IF you do not use probe GND "long wire" "inductor" for signal GND. From oscilloscope GND arrive lot of "noise" signals ant they trawel via this wire and continue they "travel" to somewhere forward... This GND wire is inductance for these high frequency components and it produce signal over this GND wire etc bad efects.
You can reduce this problem if you need look low level signals.
If it is possible do NOT use probe GND wire at all.. take it away and do probing like this attached image, even if you handle low frequency signals. (becouse, part of this noise is high frequency and these need handle so that they do not pollute signal outside of oscilloscope using this GND wire reactance)
With slow horizontal speeds you see just spikes and random "chaos" but in real world they are high frequency "signals". It can easy see using example other fast oscilloscope and spectrum analyzer. (also what you see depends samplerate becouse with low freq signals you use low horz speed and perhaps low samplearate what affect aliasing with these high freq components of signal (these noise components)
This image is good "thumb rule" how you need probe. And keep this GND connect as short as possible (around same as center pin..)
Image is borroved here
http://www.power-eetimes.com/en/evaluating-a-dc-to-dc-converter-in-the-lab.html?cmp_id=71&news_id=222904246 (http://www.power-eetimes.com/en/evaluating-a-dc-to-dc-converter-in-the-lab.html?cmp_id=71&news_id=222904246)
I have tested and example with 10mVpp 1kHz signal from enough clean signal generator and using Owon probe with 1x setting and scope 5mV/div give clean signal. With GND longwire... can see only " total chaos". (fatty trace where noise p-p is around same (10mVpp) as signal itself. )
And more fun. If probe 10x and signal 100mVpp noise is nearly also 100mVpp. Of course then what you see depends samplerate.
With short GND noise is gone.
This is NOT solution for this problem. But in many cases before real help, with this you can walk in many cases.
This just like first help before doctors come...
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:-//
After reading that i think the Doctor will be there quite soon imo ...
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Just purchased (Feb 2013) a OWON SDS7102 and I am also having the new noise issue on both channels. As soon as I turned the unit on for the first time I noticed the background noise on the traces.
Its always present regardless of voltage setting, earthing , probes, no probes. Amazing units have got out of factory with this issue.
Anyone have any further news on solution, .... it is still holiday in China, this may mean a big wait.
I guess I will need to contact the supplier about the issue as well.
|O
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Just purchased (Feb 2013) a OWON SDS7102 and I am also having the new noise issue on both channels. As soon as I turned the unit on for the first time I noticed the background noise on the traces.
Its always present regardless of voltage setting, earthing , probes, no probes. Amazing units have got out of factory with this issue.
Anyone have any further news on solution, .... it is still holiday in China, this may mean a big wait.
I guess I will need to contact the supplier about the issue as well.
|O
If you are seeing the noise even when using a fully shielded coaxial cable connection to the signal source then you are experiencing something different than what my unit is doing. Either way, agree that QC does not seem to be Owon's strong suit. Can you post any screen captures for reference?
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We can be more specific : 120mV pk-pk - how does it display ?
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I guess it is not a huge amount of noise, but it is there all the time.
Surely this is not normally for these scopes?
This image is a bit fuzzy, but all I have handy at present
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The amount of noise seen on the bottom of the trace seems similar to what I get when I use the ground clip on the probe. It disappears with the springy type ground lead. Also my scope should be old enough not to be affected by current power supply issues.
Can you switch to peak mode and zoom in on the noise there?
Also how clean is your environment with respect to electrical fields? Do any other scopes (if you have them) show any similar issues when near the SDS7102? Do you have any computers, telephones, CCFL sources or similar "dirty" devices nearby?
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Here is some tests how probe GND affect - with scope what have this special "GND noise" issue (http://owon.freeforums.org/under-work-about-gnd-noise-t21.html)
Later, after work is more ready I will add information also here. Now just lack of time.
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I will go and test now. But it seems your test frequency is 20KHz? How about looking at signals at 1KHz or so ? Surely at those frequencies the signal should be crystal clear. Also is your mode peak or sample?
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I will go and test now. But it seems your test frequency is 20KHz? How about looking at signals at 1KHz or so ? Surely at those frequencies the signal should be crystal clear. Also is your mode peak or sample?
Noise is same what ever is test signal frequency. This oscilloscope GND noise is exactly same - even if test with DC. (Visibility is other case... it depends how you set horizontal speed and what is samplerate and what is sampling mode (with low samplerates peak mode give it) Using 10-20us/div there can just see separate peaks (these most high level noise peaks). If go more deep it can easy find what these peaks include. They include high frequency oscillations even up to over 200MHz. (with low samplerates and normal acquire mode these generate of course also aliazing (together how samples are displayed on the screen low resolution related to sampled points), so these displays may be very confusing)
20kHz was selected as compromize for better visibility to noise so that there also can see full cycle of test signal and so that I can easy adjust Owon and Tektronix TDS520 for same sampling rate. (TDS520A is 500MSa/s 500MHz (repetitive) so becouse there is 500MHz analog front end in some tests there is selected 100MHz BW so that it is more compatible with Owon. If I use full BW Tek looks more noisy than Owon (also without any signal).
Owon analog BW is nearly 200MHz so it show littlebit more noise than Tek with 100MHz BW) Here you find more tests also about Owon noise and other signal quality things. (http://owon.freeforums.org/some-tests-with-new-sds7102v-version-2-6-and-2-8-2-t10.html)
About peak or normal. In these test images sampling "Normal".
Peak do not make so much becouse in first (Scope GND noise test) part there is used maximum samplerate.
Peak mode give more if there is low samplearate. (becouse ADC work always with full speed and low samplerate means just only that more or less samples are dropped out. In peak mode it try find peak values also from these samples what are dropped out.
Example in one channel use ADC work always 1GSa/s and if displayed samplerate is 100MSa/s it means that it takes every tenth sample and 9 samples just drop out. In peak mode it watch also these dropped out samples and "displayed" sample is (perhaps) highes in this 10 sample group or something like it. (of course it meand also that timing go wrong but this do not matter. (it can see if zoom in (stopped capture) and if know exactly signal and its peaks timing... )
(About this "noisy GND": work for analyzing oscilloscope internal circuits is under work. I have some "findings" but too early to talk more about these. Also priority go so that I will give all information to Owon first and later look what part of information is public and what is not.)
Things measured without opening oscilloscope and these findings, they are of course public. This GND noise spectrum is wide. From low freq up to around over 250MHz. This is why also this probe GND method make so big effect.
Oscilloscope have power supply. It is quite new version. It also produce now more "noise" but this is only small part of this whole story. Noise produced PSU unit can also detect but this is not now this main problem. I have tested one oscilloscope without its own PSU. I have used clean linear power supply for +8.4V and for -7.6V and run scope with it (Owon PSU removed) and result is nearly same.
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Added a couple of images showing the noises issue on scope purchased Feb 2013. First is peak with probe at 1x and the second with probe at 10x
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At 2V/div it seems this "noise" is actually huge. Seems it is like a % of the signal, not a fixed amount. I am not sure anymore. Hoping there will be a simple software fix :)
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At 2V/div it seems this "noise" is actually huge. Seems it is like a % of the signal, not a fixed amount. I am not sure anymore. Hoping there will be a simple software fix :)
This signal is probe comp signal. Is it clean signal for testing oscilloscope noise? No it is not. It is only ok for adjusting oscilloscope probe compensation and nothing else. And for this purpose it do not matter if there is some noise or not. It can be even lot of more noisy and still it can use for this kind of simple probe compensation adjustment.
Also it is good to read all tests what have made for real noise tests and also it is good to understand digital oscilloscopes visible noise. These test results can read in this thread here and other threads here and also in other places.
Inside oscilloscope in signal pathway there is not noise problem. If you put clean signal to oscilloscope input BNC this Owon can competite with well known good brand oscilloscopes. If some people have not skills or knowledge and experience (or equipments to do tests) - it is just other case. It need classroom and teacher.
It is also good to read example Tektronix and Agilent materials about digital oscilloscopes noise.
Also I have made tests about noise, also used these Owon scopes what have this special "noisy GND" problem and still also these units give same kind of result as before (if keep care that noise do not externally pollute signal).
But now - in other hand - this IS real problem! And problem is just this "noisy GND" problem. It is real problem becouse it is difficult to avoid that this noise do not polute signal with normal probing methods. Even for DC there can not use normal probe GND. (becouse there is this RF noise walking through GND)
Signal pathway inside oscilloscope is clean - this problem do not pollute signal pathway inside oscilloscope any markable amount. Now with this problem this noise is added to signal externally.
I have demonstrated and proofed it many ways.
Also I have analyzed this noise and I can recognize different fractions of extraordinary abnormal noise and where from these come.
There IS problem what Owon need repair!
This problem is high EMI generated by oscilloscope and pollute oscilloscope GND with high amount of spread spectrum high frequency noise. And then externally this noise is "added" to signal and there is many ways, example probe GND wire inductance is in markable role.
This problem have NOTHING to do with software inside oscilloscope. Nothing! This is as pure HW problem as ever can be.
I have also showed (documentation include material what is not public at this time - it is not "open project") where in HW is main part of this problem.
I can repeat it here agen: Main part of this noise is generated in new version of adapter board inside oscilloscope. If you do not know what is adapter board.. it is board what connects together oscilloscope Main board, PSU and Display. main problem is this new adapter board version. Other problem is new PSU but its role is not so high as adapter board related to this noise what we have seen.
One is sure: this problem can not repair with software!
The problem can be corrected and treated only if its existence is known and admitted that there is a problem.
Whole case is now also under hard and busy work. Solution - what ever it is - is coming.
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One is sure: this problem can not repair with software!
The problem can be corrected and treated only if its existence is known and admitted that there is a problem.
Whole case is now also under hard and busy work. Solution - what ever it is - is coming.
If you say it is the new adapter board, can this board be replaced? Is it modular enough and easy to remove and replace or does it require a return to the factory? Also, can the adapter board be repaired somehow rather than replaced ? Is it a particular component on this board that needs replacing or is it a much bigger issue?
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1.
If you say it is the new adapter board, can this board be replaced? Is it modular enough and easy to remove and replace or does it require a return to the factory?
2.
Also, can the adapter board be repaired somehow rather than replaced ?
3.
Is it a particular component on this board that needs replacing or is it a much bigger issue?
1.
I say: main reason is new adapter board version (add: there may be less variations between units).
Also main PSU is one source and it may have more variations between single units due to very strange parasitic oscillations in -7.6V supply (this works also with battery use).
Both can easy change. Scope open, old card or PSU out and new in. But of course it need some "skills" to do it. First need get solution and this is Owon who need find solution and desingn how they handle this case.
2.
It may be possible. If it need change some layout - no way to repair. Only change. If there need add some component it depends what and how. Most easy case is if there need only change some simple components.
3.
It depends what is real solution.
(also earlier version produce noise but now this noise is something totally diffent level. I thing they have tried develop new adapter board version better than old. But something is now wrong... I do not like public quessing without knowledge what there have happend... it may be even so that someone change some componet type after tests in mass production phase... who knows.)
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http://youtu.be/6bKDudV2d0E (http://youtu.be/6bKDudV2d0E)
My video of GND noise.
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Now some tests and later I will add more information here. (http://owon.freeforums.org/under-work-about-gnd-noise-t21.html)
Now it is clear where from all this extra noise come. (there is several sources)
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Now some tests and later I will add more information here. (http://owon.freeforums.org/under-work-about-gnd-noise-t21.html)
Now it is clear where from all this extra noise come. (there is several sources)
First, let me express my appreciation for all the time you have put into analyzing the problem. I know you sell these units and have a financial interest in their success, but in my mind you've gone above and beyond. At this point it sounds like we need Owon to develop a solution and plan for fixing the units that have already been sold. I would greatly appreciate you keeping us updated on this process and advising us on how we should work with our suppliers to get our units fixed once Owon has provided an official response.
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Greetings to all from Moscow. Take a beginner.
I apologize for my possibly incorrect English. I use a web translator.
I disassembled and deeply researched my SDS7102(V) (s/n 1234xxxx). Power supply 8.4V and-7.6V not the cause of this noise. The problem of "GND-noise" comes from the DC/DC down-converter with an output voltage of +5.5V. Its located in the center of the L-shaped adapter board and operating frequency of about 480 kHz conversion. It has a wide range of harmonics that spread on the ground surface of the device. In my version of the adapter board this chip marked Z1094AI.
Even when on battery power, away from potential sources of electromagnetic interference - I live in a country house and conducted special experiments with the release of the house - the problem remains. If you join the probe to the outer part (GND) of the inputs, it is seen that "needle" noise - RF pollutions start to become numb from the ground to the input of the oscilloscope. Well enough to connect a short piece of wire to the probe (or even just put the factory with a hook at the tip of the probe) - capacitive displacement currents arise from the ground, the ground surface radiated interference caught probe. The same thing happens when testing external circuits with weak signals - the circuit under test begins to work as an antenna.
The best solution I see the replacement step-down converter +8.4/+5.5V to conventional linear regulator. Unfortunately, it will be at the expense of total energy consumption, but will not this annoying problem in all a very good oscilloscope.
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You have littlebit older SDS.
Can you tell what version of PSU and Adabter board is inside your oscilloscope.
Newest version I know and have inspected are
PSU: T115-N Rev 3. (partially SMD components but still single layer board)
(also +8.4V and specially -7.6V SMPS radiate high amount of EMI)
Adapter board: SDS7102_CON_V3.2 (2012.07.24)
On adapter board can you look if buck's flywheel schottky diodes are B140.
(note for possible 5.5V mod : in batery use this "8.4V" drops very very down!)
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I do not get it, why would you use switched mode supplies and converters inside an instrument that should be free of all possible sources of contamination and noise ? Why not use linear supplies with precise windings on the transformers so as to generate the least possible heat ? How hard can it be?
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Hello rf-loop,
Power board is the same: PCB-T115-N Rev 3
Adapter board: SDS7102_CON_V3.0 (2011.11.14)
(http://img-fotki.yandex.ru/get/5633/200130167.0/0_afc35_1b15ddc_L.jpg)
I conducted an audit of the scheme for the noise.
Very small portion of the RF noise produces an inverting converter circuit -7.6V, performed on the chip MC34063. Printed circuit topology of this chip on the SDS has the design flaw: ground printed track of M34063 scheme is relatively narrow (high inductance), a C-shaped.
(http://img-fotki.yandex.ru/get/5632/200130167.0/0_afc37_c8e93e4_-1-L.jpg)
(http://img-fotki.yandex.ru/get/6425/200130167.0/0_afc39_abbf617e_-1-L.jpg)
In this case, the distal end of the C-track for some reason connected to the metal case power switch. As a result of the end of the track is "hot" for the RF-harmonic converter and switch plate - a good antenna for emission of pollution.
(http://img-fotki.yandex.ru/get/5634/200130167.0/0_afc3b_77b094a0_L.jpg)
When touched the metal of power switch (GND on the designers' plans) insulated screwdriver when removing the back cover, the level of radiated EMI increases substantially. When you touch the ground with a isolated screwdriver is very close - on the output power connector of PSU or on Z-plate, this increase in noise is not happening.
At first I thought it was only at this point the problem and did some upgrades. Was cut off from the end of the ground printed track from the switch pins.
(http://img-fotki.yandex.ru/get/5636/200130167.0/0_afc3c_70c68faa_-1-L.jpg)
The main problem GND-noise persists. After that I added additional MLCC ceramic capacitors (low ESR at RF) on the input and output voltage line MC34063, and also made a wide screen-shield/ground bus on place MC34063 (screen-shield is not in the photo below).
(http://img-fotki.yandex.ru/get/5636/200130167.0/0_afc3d_afb6eb25_L.jpg)
Emission spectrum of a local 34063 changed, it disappeared some high-frequency components, but the main problem as it turned out not that.
Further research led to the bug DC/DC step-down converter +8.4 / +5.5 V. Long story as it was found. That step-down +5.5 V makes a noise and makes this slyly, "needles" switching pulse (differential current) running out on the ground of adapter board. Perhaps this can be reduced by replacing the electrolytic capacitors in the circuit at LOW ESR (chineses save at this point), maybe it will improve another topology .. But I fundamentally output is seen only in the replacement Z1094 linear voltage regulator 5V.
By the way, a little "noise" and following the +5.5 V step-down converter U21 (AST4060A) with an output voltage +3.3 V, but his contribution to the "GND-noise" is not so big.
Depending GND-noise on the battery voltage (6.6 ... 8.4V), I had not noticed. Output voltage of the converter +5,5V does not change and noise equally.
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I do not get it, why would you use switched mode supplies and converters inside an instrument that should be free of all possible sources of contamination and noise ? Why not use linear supplies with precise windings on the transformers so as to generate the least possible heat ? How hard can it be?
Two words, size and cost. A linear supply with the same current rating would be heavier and cost more to produce. Efficiency is probably a distant third since you need more voltage margin on a linear to achieve the same level of regulation.
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Depending GND-noise on the battery voltage (6.6 ... 8.4V), I had not noticed. Output voltage of the converter +5,5V does not change and noise equally.
Nice work Siri!
I did not mean noise as I told that notice about battery. I mean if think linear regulator for 5.5V
Battery terminals shut off treshold is as low as 5.2V. (it may littlebit vary between single batteries (this control is inside battery) When it is just below 6V oscilloscope still works normally and it still do not crash even if battery terminal drops to 5.2V.
Your adapter board is different.
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I did not mean noise as I told that notice about battery. I mean if think linear regulator for 5.5V
Sorry, not very well know English.
I thought about it. In SDS used 2S2P 8000 mAh Li-Po battery (series connection of two parallel cells of 4000 mAh). According to the specifications of these batteries have a lower voltage of 3.0 volts per cell. Lithium batteries do not like deep discharge, and in order to save batteries it is better not to discharge low, at least up to 3.3 volts per cell. By the way, in my SDS7102 low level indicator (flashing battery icon) runs from 6.79 volts and below.
Thus, we assume that the lower the operating voltage of the battery is about 6.6 volts. If instead of a noisy step-down DC/DC converter to use a linear regulator to 5V low dropout voltage then such a change seems possible.
My pre-selection is LM1084-5.0: an output voltage of 5V and a current of up to 5A voltage drop no more 1.3 V.
But there will be an increase in the total supply current oscilloscope is estimated about 1.5 times.
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I did not mean noise as I told that notice about battery. I mean if think linear regulator for 5.5V
Sorry, not very well know English.
I thought about it. In SDS used 2S2P 8000 mAh Li-Po battery (series connection of two parallel cells of 4000 mAh). According to the specifications of these batteries have a lower voltage of 3.0 volts per cell. Lithium batteries do not like deep discharge, and in order to save batteries it is better not to discharge low, at least up to 3.3 volts per cell. By the way, in my SDS7102 low level indicator (flashing battery icon) runs from 6.79 volts and below.
Thus, we assume that the lower the operating voltage of the battery is about 6.6 volts. If instead of a noisy step-down DC/DC converter to use a linear regulator to 5V low dropout voltage then such a change seems possible.
My pre-selection is LM1084-5.0: an output voltage of 5V and a current of up to 5A voltage drop no more 1.3 V.
But there will be an increase in the total supply current oscilloscope is estimated about 1.5 times.
Owon oskilloscope is watching batt voltage only for display. Oscilloscope do not control and shut off battery! It is battery control logic inside Hangzhou Wanma made battery module. This main switch is inside battery. After module itself shut off then battery module output go to high impedance state but current can flow to inside battery using same terminals.
This shut off treshold is around 5.2V if measure it so that scope run with battery until battery module internal control shut off. (in these battery modules what I have tested.)
With this voltage it is still not "deep discharged" (becouse this voltage is of course measured with quite high load and there is battery internal source resistance - after loading stop (battery internally shutted off) of course internally battery voltage is higher after load is zero.
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In new Adapter card there is 5.5V converter and TFT back light control. Both of these produce high noise. 3.3V converter is acceptable.
Owon need find solution for this problem what they have done. Also they need modify main Power unit for lower EMI.
Before Spring Festival I have talked with Owon about this problem and I have promised to Owon that also I will send full test documentation to Owon monday 18.Feb (they arrive back to work).
And "I have feel" that there are also some others doing same work.
Other problem after solutiion is: How to arrange repair for these units what allready have sold around of world.
This "engineer" who have made these modifications in Owon - there is not easy days waiting in work - if he arrive back to work from holiday.
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rf-loop, thanks for the information about the features of the battery.
I wonder if all batteries present more protective electronic module. Outwardly, it does not. Maybe it does and the desired balance in charge of cells? .. Interesting point. But in any case to bring the battery to such a low voltage and power off is not necessary. Oscilloscope itself has no off the low voltage, certainly a disadvantage.
On the main ADC/CPU board is squeaker. Let the developers though, in the new firmware would make a nasty sound alarm reminder low battery discharge. It will be a complementary solution to protect the battery.
The problem of "gnd-noise" in the SDS is, as they say Russian, a fly in the ointment. Trifle spoils in all an excellent device.
Unfortunate "needle" that is present on the ground surface of the device - it fronts 480 kHz switching step-down converter +5.5V. Need to change the scheme of this converter. Perhaps, on a scale the world has sold instruments some solution would be to add the electrolytic capacitors with ultra low ESR an input and output. We must try. But such necessary (and quality!) components are relatively expensive and scarce. This itself upgrade will be in this respect more difficult to install, for example than nylon column close to the first channel.
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Can we not simply disable the +5.5V completely and add a linear regulator or some such to provide the +5.5V ? That would get rid of the 480KHz noise generator.
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Can we not simply disable the +5.5V completely and add a linear regulator or some such to provide the +5.5V ? That would get rid of the 480KHz noise generator.
That's what I plan to do in my SDS7102. This will be the fundamental solution to the problem. The problem is that so far have not found LM1084-5.0 in the local stores :) The voltage in the circuit of the oscilloscope in this place can be reduced to 5 volts, and the chip in my opinion would be the best choice.
The following quote method or identify GND-noise.
Disconnected and removed the back cover, the device is powered by a battery.
As a local probe is used without the ground wire-crocodile. Short (5-6 mm) needle of the end of a high impedance probe - good mini-antenna for local search. Bringing the needle probe to different segments of the device can see the local emission.
For example, the inverting converter -7.6V on board the PSU (chip MC34063) operates at a frequency of about 63 kHz. Emission at the surface of the chip:
(http://img-fotki.yandex.ru/get/5647/200130167.0/0_afd5c_7c8bd0d6_L.jpg)
(http://img-fotki.yandex.ru/get/5636/200130167.0/0_afd53_f7f81027_L.jpg)
And near the inductance of this converter:
(http://img-fotki.yandex.ru/get/4126/200130167.0/0_afd55_57076d42_L.jpg)
Step-down converter +3.3V (it is set in the following scheme of the problem after converter +5.5V and powered by it):
(http://img-fotki.yandex.ru/get/6447/200130167.0/0_afd5b_6af6f6c7_L.jpg)
(http://img-fotki.yandex.ru/get/4117/200130167.0/0_afd56_6c57daf0_L.jpg)
Emission near inductance converter +5.5V 480 kHz (note the sharp current spikes):
(http://img-fotki.yandex.ru/get/6427/200130167.0/0_afd58_a9d4dde3_L.jpg)
Compare this timing (match the cursor and time stamps) with matching fronts pollution on the ground surface of the device. More significant for this would be the use of two channels, but I limited myself to one:
(http://img-fotki.yandex.ru/get/6442/200130167.0/0_afd59_40123b68_L.jpg)
(Here running triggers on the rising edge and the waveform is slightly shifted with respect to current spikes in the converter +5.5V. But the hero of our "celebration" became known).
-
LM1084-5 ? Do we really need 5 amps ?
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LM1084-5 ? Do we really need 5 amps ?
Of course not. 5 A is the current limit for this regulator. In the scheme SDS7102 bus +5 V requires 2 A (+/-). I do not know exactly, but I assume this figure based on the total current consumption.
In 1084 when this current is less than the voltage drop (about 1,0V), unlike other, less powerful series regulators, where the voltage drop will be greater if we desire a current.
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SDS7102
It was RuiFeng ADC...
now there is:
(picture is from SDS7102 1240xxx)
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OK... What is that ADC IC? I could not find the datasheet anywhere.
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OK... What is that ADC IC? I could not find the datasheet anywhere.
Old was: MXT2002 (RuiFeng China)
MXT2002 is National ADC08D500 "clone". (exept case. ADC:128pin, MXT:144pin))
Now there is National logo and (looks like customer part number?) as can see there is 128pin but....
Who knows.
Functionally looks like as before.
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My spoon of tar in a barrel of honey:
http://owon.forumup.com/about153-owon.html (http://owon.forumup.com/about153-owon.html)
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In addition, the threads about ground noise bring their latest research results.
Once again, sorry for the English may incorrectly.
SDS7102V SN 1234XXXX
Viewed the “ground noise” correlations with switching power supply uses two channel oscilloscope.
Content is done at the same SDS7102, power produced by the battery.
(http://img-fotki.yandex.ru/get/5629/200130167.0/0_afee0_7d3dd8c9_-1-L.jpg)
The second channel is connected to ground and seen polution noise. Trigger synchronization starts on the first channel. Connected to the first channel "empty" probe. End (short needle) is used as a capacitive local antenna. When approaching the needle to the schema components can be seen local emissions. Both probes have a bandwidth of 250 MHz.
(http://img-fotki.yandex.ru/get/4120/200130167.0/0_afede_8927370f_L.jpg[/url])
(http://img-fotki.yandex.ru/get/5634/200130167.0/0_afedf_3ae9230b_-1-L.jpg[/url])
"GND noise" is already known to many owners of problem party of 7102. This chaotic sharp bursts, on closer inspection it is decaying burst with a frequency of about 100 MHz.
(http://img-fotki.yandex.ru/get/6444/200130167.0/0_afecb_d30eba0c_L.jpg)
(http://img-fotki.yandex.ru/get/4132/200130167.0/0_afecc_cbbc89f0_L.jpg)
(http://img-fotki.yandex.ru/get/6436/200130167.0/0_afecd_8bc5be9b_L.jpg)
Below view of GND-noise emissions from various DC / DC converter power supply circuit SDS7102.
1. Converter -7.6 V. Board PSU, IC3 (chip MC34063), the frequency of about 63 kHz
(http://img-fotki.yandex.ru/get/6442/200130167.0/0_afee1_921878a6_L.jpg)
(http://img-fotki.yandex.ru/get/4126/200130167.0/0_afeef_2a7f1396_L.jpg)
(http://img-fotki.yandex.ru/get/6433/200130167.0/0_afeee_f6605e06_L.jpg)
Conclusion: there is a very weak ringing high-frequency of the rise edge.
I recall that in my 7102 this step-down converter is modified, reduced pollution from him (https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/msg192647/#msg192647 (https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/msg192647/#msg192647)).
2. Converter +3.3 V. Adapter board, U21 (chip ACT4060A), frequency of about 380 kHz:
(http://img-fotki.yandex.ru/get/5634/200130167.0/0_afee2_1b349e0d_L.jpg)
(http://img-fotki.yandex.ru/get/5647/200130167.0/0_afeeb_16f6773d_L.jpg)
(http://img-fotki.yandex.ru/get/5639/200130167.0/0_afeec_4854eba7_L.jpg)
(http://img-fotki.yandex.ru/get/4129/200130167.0/0_afeed_9bd35566_L.jpg)
Conclusion: there is a very weak overlap at the front switch. Impact is minimal.
3. Converter +2.8 V. Adapter board, the chip labeled "1780 TB51», frequency of about 1200 kHz:
(http://img-fotki.yandex.ru/get/4131/200130167.0/0_afee3_b825d_-1-L.jpg)
(http://img-fotki.yandex.ru/get/4117/200130167.0/0_afef0_1578468e_L.jpg)
(http://img-fotki.yandex.ru/get/6440/200130167.0/0_afecf_bc7ab326_L.jpg)
(http://img-fotki.yandex.ru/get/4120/200130167.0/0_afed0_50854576_L.jpg)
Conclusion: does not bring influence.
4. Converter +8.8V. Scheme pulse LCD display backlight. Adapter board, U8 chip labeled "5126Q".
The emission of this schema has an interesting look. Short burst repetition rate of about 30 kHz. Frequency of the pulses themselves about 860 kHz (in this example, the brightness of the display is minimal - 20%).
(http://img-fotki.yandex.ru/get/5646/200130167.0/0_afee4_2fd6a0fa_-1-L.jpg)
(http://img-fotki.yandex.ru/get/5641/200130167.0/0_afedc_ddcbd95_L.jpg)
(http://img-fotki.yandex.ru/get/5631/200130167.0/0_afedd_bef90d06_L.jpg)
(http://img-fotki.yandex.ru/get/4128/200130167.0/0_afed2_d5633e94_L.jpg)
(http://img-fotki.yandex.ru/get/4119/200130167.0/0_afed3_626dd11b_L.jpg)
(http://img-fotki.yandex.ru/get/4133/200130167.0/0_afed4_b4ea9e6e_L.jpg)
Conclusion: The significant ringing overlap is from the fronts. Tangible impact. Because of the instability frequency converter introduced them part of the noise is a random character.
5. Converter +5.5V core supply. Adapter board, the chip is marked Z1094AI.
Synchronizing GND-noise with this converter explicit. Unfortunate "spikes" of noise is exactly the same with the rear switch fronts. There is also a previously identified high-ringing generation at frequencies around 100 MHz.
(http://img-fotki.yandex.ru/get/4136/200130167.0/0_afee5_9bee87f6_-1-L.jpg)
(http://img-fotki.yandex.ru/get/5635/200130167.0/0_afed7_24530174_L.jpg)
(http://img-fotki.yandex.ru/get/4133/200130167.0/0_afeda_bff015ea_L.jpg)
(http://img-fotki.yandex.ru/get/5638/200130167.0/0_afed9_924883d8_L.jpg)
(http://img-fotki.yandex.ru/get/6425/200130167.0/0_afedb_820c5d25_L.jpg)
Conclusion: this converter provides the main pollution and creates "GND-noise”.
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Nice work Siri.
Here can find link to these old . (http://owon.forumup.com/viewtopic.php?t=269&mforum=owon)It is 1.17M zip including some images and part of explanation txt file. This is small public part from full documentation between me and Owon during inspection and for solve this terrible design error(s) what someone have done. Also many other peoples have done lot of work for resolve this problem. (but most of my recommendations how to handle this whole terrible case they just did not listen - they select road for destroy Owon reputation for long time. Pity.)
Still with or without this problem, with what ever oscilloscope it is very important how we use probes and how we design how to connect to devive under test for reasonable clean signal. It need knowledge and it need experience.
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Here can download some part of tests.
...
Big and excellent work, rf-loop!
Our results are very similar. Apparently the main sources of noise is a +8,8V TFT Backlight LED power supply and +5.5V step-down dc/dc converter.
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Siri and RF-Loop
A very big thank you for the detailed investigation into the power supply noise problem on the Owon SDS7102. I have done similar things, so know you have both spent many many hours investigating it, then more time to document it for the forum and as an assist to Owon to get a "fix" for it.
I sincerely hope that Owon reacts quickly and thoroughly to what may be a significant field repair. It is very hard to imagine that they have not known about this problem for a while, as they see the feedback from the worldwide distribution.
I would imagine that sales of new scopes will be substantially reduced until this is resolved.
In my case, I was about to order a SDS7102 from a US distributor, but there is no way that will happen until this is resolved. In my opinion, it would be difficult for any seller to service a product with this kind of a problem until the factory can provide him with a fix. It does not look like "just tighten these screws" will fix it - but we can always hope...
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Is this a problem that all SDS7102 scope from Owon has or is it certain hw versions? And from what version in that case? Thanks.
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Are all these "faulty" components all situated on one replaceable card or is it more complicated than that?
Is there any merit in trying to replace just the 5.5V DC step down converter with a linear regulator or it will not achieve much?
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Are all these "faulty" components all situated on one replaceable card or is it more complicated than that?
Is there any merit in trying to replace just the 5.5V DC step down converter with a linear regulator or it will not achieve much?
It is good to note that "Siri" tests have made with older version where adapter This new version of Adapter board have better 5.5V. There is no any need for linear power supply, exept of course if someone want do it for himself. There is now specified 4 hour time with battery (after quite short time period after charging). No one want reduce this time. SMPS is only solution for this.
Then it is also good to note that probing method may reduce this noise in most cases. When people use oscilloscope it is also good to learn many things about probing devices/signals under test. In real world today there is lot of many kind of EMI noises all around what may externally add noise to signal. Same methods reduce these and also oscilloscope own EMI. It is good to note agen: There is not any extra noise in oscilloscope signal pathway! This Owon front end is still one of best in this price class if look its noise. Take some halfway of 2011 made SDS and new SDS there can see that analog front end noise is reduced really dramatically.
I have get one old SDS for compare to new one.
I have add 5 small capacitors and cut one trace in main PSU and with normal "bad method" probing whole noise is better than old SDS. With good probing practice/methods difference is big. This "noisy" new Owon beats this old "no noise problem" SDS just like 1-0.
But one note: Old owon front end "pink"noise level is so high that these kind of very small peaks can not detect at all becouse they are there under front end base noise level.
This all do NOT mean that nothing need do.
It means that noise level can reduce (and need reduce) to normal acceptable level by adding agen all noise related components what they have dropped out slowly after version to version and finally forget all out from new version (ecxept 5.5V supply is littlebit different case).
They need return + add some new components and/or change some components type and in later versions change also PCB topology for reduce inductances and also some capasitances. Aftere then maybe these noise filtering components can reduce. (If do not make noise then it do not need isolate/attenuate! It need keep as main principle.)
Special critical is inside every single SMPS. There need keep current loop(s) as short and low impedance as possible. And take care that keep "GND" current loops tightly separate from each others and then use "one point" together method in final. Before "out".
Someone may think that low ESR electrolytics --- yes of course need but they are not enough at all, they are for audio frequencies (and it is not this case), they have no role with 20 to 200MHz. Adding some ceramic capasitors. Yes but types what really can handle RF. And 200MHz in mind it is also critical where they are becouse PCB traces have inductance. In wrong place they may do situation even more bad.
Later it can do even better if littlebit change adapter board and main supply PCB routing / topology.
Here also very fun picture.
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I am not sure I agree about the "probing method" as you call it. This is not a user's fault.
I have a 20 year old 20MHz scope that has no trouble at all locking on and displaying very clearly the same traces that the Owon cannot lock on and display.
It is like buying a brand new car that can do 120mph but cannot take a corner at 20mph whereas your 20 year old car cannot do 120mph but has no trouble taking a corner at 20mph. You cannot possibly say this is the driver's fault.
So what we need is a way to fix the Owon. I would rather the Owon became a 20MHz scope that works than a 100MHz scope that does not. I do not think Owon will accept that there is a fault and I doubt they will start replacing all the old scopes. Imagine the costs of shipping all the old units back to China.
I think the best solution would be to find a way that we can DIY fix this by adding capacitors, maybe cutting out tracks like you did and so on.
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I am not sure I agree about the "probing method" as you call it. This is not a user's fault.
I have a 20 year old 20MHz scope that has no trouble at all locking on and displaying very clearly the same traces that the Owon cannot lock on and display.
It is like buying a brand new car that can do 120mph but cannot take a corner at 20mph whereas your 20 year old car cannot do 120mph but has no trouble taking a corner at 20mph. You cannot possibly say this is the driver's fault.
So what we need is a way to fix the Owon. I would rather the Owon became a 20MHz scope that works than a 100MHz scope that does not. I do not think Owon will accept that there is a fault and I doubt they will start replacing all the old scopes. Imagine the costs of shipping all the old units back to China.
I think the best solution would be to find a way that we can DIY fix this by adding capacitors, maybe cutting out tracks like you did and so on.
Of course it need repair without any doubt!
---------------
Probing methods understanding is other important case. It is NOT solution to this problem. But also with it, after understand it, it may help now markable amount. Good probing practices and knowledge is usually very very underestimated specially if we look entry level.
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Hello rf-loop,
Good and useful notes.
Today I replaced the old electrolytic capacitor 470 uF 16 V (directly to the output of the converter to +5.5V) --> low ESR 330 uF 16 V by Hitano. Ground noise is not reduced. It seems the whole thing is really a circuit topology of pulsed power converters. I have told earlier that eliminate defects in the inverter topology -7.6 V on MC34063. There it gave some result.
Apparently it is (has become) a big problem for Owon. Requires effective and speedy solution. While each new oscilloscope sold Owon expands the number of potential claims. Apparently simple solution of recommendation such as "replace a capacitor(s) on this" will not work here, and it smells like at least the replacement adapter.. Will this step Owon?..
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Hello rf-loop,
Good and useful notes.
Today I replaced the old electrolytic capacitor 470 uF 16 V (directly to the output of the converter to +5.5V) --> low ESR 330 uF 16 V by Hitano. Ground noise is not reduced. It seems the whole thing is really a circuit topology of pulsed power converters. I have told earlier that eliminate defects in the inverter topology -7.6 V on MC34063. There it gave some result.
Apparently it is (has become) a big problem for Owon. Requires effective and speedy solution. While each new oscilloscope sold Owon expands the number of potential claims. Apparently simple solution of recommendation such as "replace a capacitor(s) on this" will not work here, and it smells like at least the replacement adapter.. Will this step Owon?..
Even if there is as low as 1nH and frequency is 100MHz, inductive reactance XL is 1.25ohm
But in practice there may be many times this inductance and some frequencies go up to 200MHz or even over. These "low ESR" electrolytic capacitors are good as long as there need handle low frequencies but they can not do nearly anything in this frequency area. 4mm long, 0.25mm copper wire is around 2.5nH. ( 100MHz XL is around 1.6ohm) Now I ask what is low ESR capacitor real impedance with 100 to 200MHz.) How about PCB GND trace impedances with this freq?
(btw: I know Owon is now working for this)
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As customers, what in your opinion should we be hoping for from Owon? A complete replacement of the scope (very expensive due to shipping costs to China), repair by local dealers (I am not sure if there are any local dealers in the UK), or maybe DIY instructions of how to repair it?
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:-BROKE Well, in 11/2012 I was thinking about buying an Owon... Today not at all. :(
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As customers, what in your opinion should we be hoping for from Owon? A complete replacement of the scope (very expensive due to shipping costs to China), repair by local dealers (I am not sure if there are any local dealers in the UK), or maybe DIY instructions of how to repair it?
If it comes to the need to replace the adapter card or PSU, and the dealer does not (or can not carry out repair / replacement), both version will be sending everyone a new card for itself replace it. Owon save face and will gain more trust/respect.
You need only reflect on the mechanism to confirm the possession of the problematic device: such as sending them a foto of the oscilloscope with serial number, etc.
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...
These "low ESR" electrolytic capacitors are good as long as there need handle low frequencies but they can not do nearly anything in this frequency area. 4mm long, 0.25mm copper wire is around 2.5nH. ( 100MHz XL is around 1.6ohm) Now I ask what is low ESR capacitor real impedance with 100 to 200MHz.) How about PCB GND trace impedances with this freq?
(btw: I know Owon is now working for this)
Of course the problem of "noise" inherent principle of pulsed sources, literacy circuitry and component selection. There are special (with an operating frequency of up to several hundred kHz) series of capacitors with Low ESR and impedance. Though there main goal is to reduce the output voltage ripple.
In the first review, I did not see obvious blunders in the topology of the adapter board. But I'm not a super expert in this. Perhaps the noise comes from the absence of the rule of "one point of common ground." Also, it is likely that the sharp edges on "the ring" of their spurious own resonance in inductors. For example, I see that in my converter +5.5 installed in 5.6 uH inductance, and the photo of the former unit of 2011 MY this inductance is 15 uH.
And I think in the devices in 2011 in this converter used a different chip.
my bad English ... Sorry if there are awkward phrases :)
(UPDATED)
Hooray. A simple solution is almost completely eliminated the "GND-noise" of the converter +5,5V in my version of the adapter board. Overall noise level dropped by nearly four times.
Most were noise from the circuit display.
Details tomorrow (ie today, Moscow time).
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or maybe DIY instructions of how to repair it?
I would be happiest with this option.
Thanks rf-loop and siri for contributing on this issue.
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(UPDATED)
Hooray. A simple solution is almost completely eliminated the "GND-noise" of the converter +5,5V in my version of the adapter board. Overall noise level dropped by nearly four times.
Most were noise from the circuit display.
Details tomorrow (ie today, Moscow time).
Hey Siri:
The suspense is killing me!
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As suggested earlier, the important cause of failure in the topology switching powers.
The simplest solution to slightly reduce the gnd-noise converter +5.5V is a way of shortening the path length of the pulse current on copper coated PCB. To do this:
- Turn the D127 so that its anode connected to the ground at a nearby ground, next to the hole mounting board to the metal Z-base (pre-need to clean and tin the landfill site for a new soldering points):
(http://img-fotki.yandex.ru/get/5647/200130167.0/0_b0d45_47ea633_-1-L.jpg)
- Cut the two ground wires from the connector of adapter board and solder them to the ground plane in soldering the anode of the diode. The photo below is the place indicated "Better." (It is seen as the beginning I tried to connect the wires to the GND in the corner of the polygon adapter).
(http://img-fotki.yandex.ru/get/5627/200130167.0/0_b0d46_7205aa72_L.jpg)
In my case, the noise from the converter +5.5V decreased by three to four times. But now was significant noise from the pulse backlight TFT circuits +8,6...9,5V.
By the way, I tried to disable backlight switching circuit and power the lights directly from the circuit +8.4 V. Brightness greatly reduced and therefore the oscilloscope was almost impossible to use, but the noise was almost no more.
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Interesting bit of research!
Also I'd like to thank you for awesome illustrations!
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As suggested earlier, the important cause of failure in the topology switching powers.
The simplest solution to slightly reduce the gnd-noise converter +5.5V is a way of shortening the path length of the pulse current on copper coated PCB. To do this:
...
In my case, the noise from the converter +5.5V decreased by three to four times. But now was significant noise from the pulse backlight TFT circuits +8,6...9,5V.
By the way, I tried to disable backlight switching circuit and power the lights directly from the circuit +8.4 V. Brightness greatly reduced and therefore the oscilloscope was almost impossible to use, but the noise was almost no more.
Hi Siri,
Great investigation and supurb illustrations. It was worth the wait.
Can you show us an example of a trace from your files showing the ground noise before the mod and a similar trace now?
Thanks for all your hard work.
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Hello DrBob!
As I said it reduces the overall noise somewhere in the 3-4 times. Tomorrow I'll post my final image noise. BUT! It will not be very relevant to this modification pictures, will be slightly better. After this upgrade, I had a deeper (and really "hard work" :) ) with a desire to further improve results. This includes trying to improve the topology of backlight pulse circuit. In the end, it's my adapter board has quite jaded view :)
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https://picasaweb.google.com/107445062668018969562/DropBox?authuser=0&authkey=Gv1sRgCMeok-GdvqTjGA&feat=directlink (https://picasaweb.google.com/107445062668018969562/DropBox?authuser=0&authkey=Gv1sRgCMeok-GdvqTjGA&feat=directlink)
Thats my noise after soldering. It seems that the ripple smooth or simply tightened. Can be compared with the photo Siri on previous pages. GND is not cut from a line.
Still bad, frequency in main spike nearly 87 MHz
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Thank you Siri about this Diode turn. Good finding!
(whole "noisy GND" case is under work in Owon)
After 2011 there have been many modifications on the Adapter board. If look old 2011 board and today board it is difficult to think they are from same SDS model. And between these there have been many many changes after changes.
Also note that after this version what "Siri" have there is many changes in Adapter board.
V3.2 board TFT backlight LED power circuit is also changed lot of between these versions.
This version is like jammer transmitter. (but it is easy piece of cake in this whole "noisy GND" case.)
But solution for one version is propably not solution for other version!
This main problem is that whole GND mess is like "magpie nest" if think high frequencies when switching circuits works.
Switching current loops in separate SMPS circuits are just like kids design who have only designed DC things. Perhaps after it have started to modify after 2011 somebody have forget to watch noise when he change layout.
Good (just one simplest) example is this C34. What hell this designer have thinked when he handle this switcher output. Perhaps just nothing but next lunch time.
(picture is from factory original SDS7102 adapter board V3.2.)
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Thank you Siri about this Diode turn. Good finding!
This idea was suggested to me in correspondence my Ukraine colleague alexuresp. Thanks to him!
Can you show us an example of a trace from your files showing the ground noise before the mod and a similar trace now?
Below the picture noise my SDS7102v after deep changing adapter board. Measurements made in the same place, and the conditions and rules in my post earlier (https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/msg193325/#msg193325). Let me remind the noisiest sites in my previous study revealed dc-dc converter +5.5V and pulse circuit TFT backlight. I will repeat here the old pictures for comparison.
But it all worked out to get not just "turn" of the diode. Were made much larger changes in the adapter and I can not recommend it because of the complexity and individuality of this work.
(http://img-fotki.yandex.ru/get/4120/200130167.0/0_afede_8927370f_L.jpg[/url])
First the overall picture noise.
So it was:
(http://img-fotki.yandex.ru/get/6444/200130167.0/0_afecb_d30eba0c_L.jpg)
Thus it became:
(http://img-fotki.yandex.ru/get/5647/200130167.1/0_b0e9d_fddf1ab_L.jpg)
So it was:
(http://img-fotki.yandex.ru/get/4132/200130167.0/0_afecc_cbbc89f0_L.jpg)
Thus it became:
(http://img-fotki.yandex.ru/get/5646/200130167.1/0_b0e9e_89c38623_L.jpg)
The noise of the dc-dc converter +5.5 V.
So it was:
(http://img-fotki.yandex.ru/get/5638/200130167.0/0_afed9_924883d8_L.jpg)
Thus it became:
(http://img-fotki.yandex.ru/get/5636/200130167.1/0_b0e9c_5cec771c_L.jpg)
The noise of pulse circuit TFT backlight.
So it was:
(http://img-fotki.yandex.ru/get/4128/200130167.0/0_afed2_d5633e94_L.jpg)
Thus it became:
(http://img-fotki.yandex.ru/get/6701/200130167.0/0_b0e9a_d9207697_L.jpg)
So it was:
(http://img-fotki.yandex.ru/get/4119/200130167.0/0_afed3_626dd11b_L.jpg)
Thus it became:
(http://img-fotki.yandex.ru/get/5646/200130167.0/0_b0e9b_adefdc8a_L.jpg)
And finally, an example of a picture waveform from the built-in generator (with a tip-hook and with the ground wire-crocodile, probe in position "X10").
(http://img-fotki.yandex.ru/get/4123/200130167.1/0_b0e9f_1f586d3a_L.jpg)
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Hi guys i got a perfect solution i think.
https://plus.google.com/photos/107445062668018969562/albums/5847922453850803761/5848219105755079794?authkey=CMeok-GdvqTjGA&banner=pwa&gpsrc=pwrd1#photos/107445062668018969562/albums/5847922453850803761/5848219105755079794?authkey=CMeok-GdvqTjGA&banner=pwa&gpsrc=pwrd1 (https://plus.google.com/photos/107445062668018969562/albums/5847922453850803761/5848219105755079794?authkey=CMeok-GdvqTjGA&banner=pwa&gpsrc=pwrd1#photos/107445062668018969562/albums/5847922453850803761/5848219105755079794?authkey=CMeok-GdvqTjGA&banner=pwa&gpsrc=pwrd1)
Thats easy and u can try, but need small one to close the case.
(https://lh4.googleusercontent.com/-a6a1kVCCfew/USkiHY1R4kI/AAAAAAAACIs/47v-wxp9mDI/s693/IMG_7383.JPG)
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Aleksandr, ne znal otkuda ti sam i seychas popravil svoy post na "ukraiskogo kollegu" :)
Kstati ferritovuyu zashelku na schleif provodov ya poprobobal stavit' srazu, no u menya eto ne dalo bol'shoy polzi. U tebya namnogo snizilsya shum?
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Da shum upal prilichno, no eto v komplekse so vsemi peredelkami.
Dumayu esli postavit' ferrit to mojno zemlu ne brosat' na pryamuyu. No korpus ne zakrivaetsia iz za ruchki, mojet prosto poprobovat' obmota' ekranom shleyf. No nujen skotch takoy.
Otot gorb na fotah v albome pochti ne vidno.
dobavil fotki v al'bom mojno sravnit'
(https://lh5.googleusercontent.com/-y3lkIRp063k/USkbMUreg7I/AAAAAAAACIU/0oequnedgTA/s693/1671628410.jpg)
The noise is not gone, it became less and filtered. This is not ideal, and for each will require a different approach.
Perhaps Owono correct it in the next version and break something else%)
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Da shum upal prilichno, no eto v komplekse so vsemi peredelkami.
Dumayu esli postavit' ferrit to mojno zemlu ne brosat' na pryamuyu. No korpus ne zakrivaetsia iz za ruchki, mojet prosto poprobovat' obmota' ekranom shleyf. No nujen skotch takoy.
Otot gorb na fotah v albome pochti ne vidno.
U menya v itoge minus podayetsya vse-taki na ugol platy, kak na fotke raneye. No sama plata perepakhana tak chto strashno smotret'.
Nu i nizhe rasshifrovka dlya nenashikh tovarishchey.
(Ferrite clip tried before, but the result is small.
I finally did gnd wires served by the angle of the board as in the photo above. But the board plowed so scary looking.)
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Some kind of an interim report.
Here compared factory original with "noisy GND" issue and same model but modified.
Compare made parallel so that all other things eliminated. Same time, same enviroment EMI noise level.
Both are same version SDS7102 and both powered using same AC source.
Test setting you see in images. Probe is set for 10:1 so that its freq response is full. All tests used same probe and compensation adjusted only with modified oscilloscope. (you can see small difference becouse scope inputs capasitances are not very exactly same)
These test setup is made so easy that everyone can do this same test without any external equipments.
Note memory selection!
Probe hook and probe own long GND wire (both) connected to Probe Compensation output GND.
(If use probe tip directly + very short GND wire connected to GND it do not show this noise becouse there is not GND wire "high" inductance.)
(http://i181.photobucket.com/albums/x2/aghp55/SDSnoiseIssue/Mod_Umod_compare/1_U_GND.png)
Unmodified
(http://i181.photobucket.com/albums/x2/aghp55/SDSnoiseIssue/Mod_Umod_compare/2_M_GND.png)
Modified
Probe 10:1 and tip connected to Probe Comp out and probe own long GND wire connected to probe comp out GND.
Note Offset setting! Whole signal level (5V) from peak to peak is 100 div vertically!
(http://i181.photobucket.com/albums/x2/aghp55/SDSnoiseIssue/Mod_Umod_compare/3_U_PComp.png)
Unmodified
(http://i181.photobucket.com/albums/x2/aghp55/SDSnoiseIssue/Mod_Umod_compare/4_M_PComp.png)
Modified.
Work is not ready. Experiments, tests and work for finding best way for (simple) DIY solution is still under work.
Also waiting Owon official version for solve this problem.
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Nice work, rf-loop.
Vertical level 50 mV here with the probe X10 (ie, the actual level of 5 mV/div input)? If so you get a very good result!
Below is the gnd-noise my modified 7102 under the same settings (probe X10 with hook and long gnd-wire. 50 mV/div - the real input level of 5 mV/div):
(http://img-fotki.yandex.ru/get/5633/200130167.1/0_b10b2_94ce916d_L.jpg)
The remaining noise is derived from the periodic pulse train in the circuit TFT backlight:
(http://img-fotki.yandex.ru/get/6431/200130167.1/0_b10b3_9f0618ae_L.jpg)
I wonder how you managed so well to reduce noise backlight?
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(https://lh3.googleusercontent.com/-L_EeUxrfMFk/USuPs14eZVI/AAAAAAAACKA/Oc_Wl2J_QLc/s800/1752795065%281%29.jpg)
But the remaining noise is huge, we should try to filter it better.
On my GND noise the biggest level 60kHz from power supply.
fixed
Now the main noise from LCD.
rf-loop how you fight with this ?
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Alex, u tebya vertikal'nyi predel 50 mV pri X1. Sdelay na 5 mV.
(U menya na fotke vishe 50 mV/div eto pri ustanovke X10, t.e. fakticheski tam 5 mV po vhodu esli X1)
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Hey guys,
I have a small problem with my SDS7102 and hope you can help me.
The problem is, that the Scope starts to hang-up after a while. The LED starts to get RED, the Owon support said that this means the battery is charging but i don't have one ???
I think it is a temperature or PSU problem (or both) because the supply Voltage seams to break down (Fan gets slower)
Just want to know if anyone of you knows anything about that and how to solve it or if the problem is new.
HW-Version is 710243XX
LAN-Port only, no VGA, no RS232
Hope someone can help me
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Hey guys,
I have a small problem with my SDS7102 and hope you can help me.
The problem is, that the Scope starts to hang-up after a while. The LED starts to get RED, the Owon support said that this means the battery is charging but i don't have one ???
I think it is a temperature or PSU problem (or both) because the supply Voltage seams to break down (Fan gets slower)
Just want to know if anyone of you knows anything about that and how to solve it or if the problem is new.
HW-Version is 710243XX
LAN-Port only, no VGA, no RS232
Hope someone can help me
Perhaps your HW is 7102 1143xxx ?
Do you have any start up problem or any problem during use. Only problem is led color or any other problem?
You tell that FAN speed also drop.
(oscilloscope nominal internal main voltage without battery is 8.4V but its accepted range is around 6.6 to 8.4V and FAN runn with this voltage. All other needed voltages inside oscolloscope are derived from this around 6.6V to 8.4V main power and they stay still constant.)
You have no battery. Normal is that it works with around 8.4V (and if you turn battery indicator on it show normally in this case full battery - you can look it)
If this voltage drops randomly it tell that somewhere is problem. Problem may be on the (1. suspect) PSU itself or there is (2. suspect) extra load due to some internal fail in other parts than PSU itself. Situation is not normal if without battery these leds suddenly/randomly go red and also you can hear FAN speed drops. Still your scope may work normally. (if problem is PSU, as long as it keeps voltage over lowest acceptable)
Later if this problem go more bad it perhaps stops working. If Owon do not repair it now, then they need repair it later after it stop workig. As long as it works normally it do not have status "failed".
Also if it do it only sometimes just randomly... it is difficult case in service. Perhaps it do not go to this state in watching period.
You can turn it on and keep it on continuously example one week or run it behind timer... 3 hour on, 1 hour off... let it go until fail.
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@RF-LOOP
Now that you mentioned battery indicator, I have a question:
Would battery indicator showing slightly discharged battery when the battery itself is removed from the scope be a sign of PSU problems? How does the indicator work on this scope? Just measure the voltage? Or is it doing something smarter?
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@RF-LOOP
Now that you mentioned battery indicator, I have a question:
Would battery indicator showing slightly discharged battery when the battery itself is removed from the scope be a sign of PSU problems? How does the indicator work on this scope? Just measure the voltage? Or is it doing something smarter?
If it show slightly discharged without battery, it looks like there is not full 8.4V power supply output.
Indicator is just as simple as it can be. It do not know anything but just voltage.
Reason for low voltage is PSU or internal extra load. My quess is PSU.
If you measure be careful: do not make short circuit! There is no fuse.
(batt over current protection is inside batt module)
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Thanks a lot!
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Has anyone used the trigger holdoff on the SDS7102? I tried to use it today, but it seems that it only increments by 100ns at a time. I turned the knob for a minute and only got to 1ms. How in the world am I supposed to get to something like 100ms without turning the knob for an hour and a half? It's supposed to go up to 10 seconds.
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Has anyone used the trigger holdoff on the SDS7102? I tried to use it today, but it seems that it only increments by 100ns at a time. I turned the knob for a minute and only got to 1ms. How in the world am I supposed to get to something like 100ms without turning the knob for an hour and a half? It's supposed to go up to 10 seconds.
On mine, the faster you turn the knob the larger the increments. Still, it takes a while to get to 10S.
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Has anyone used the trigger holdoff on the SDS7102? I tried to use it today, but it seems that it only increments by 100ns at a time. I turned the knob for a minute and only got to 1ms. How in the world am I supposed to get to something like 100ms without turning the knob for an hour and a half? It's supposed to go up to 10 seconds.
Around 30 second.
If frequently need long holdoff times it is wise to store one (or two) setup profiles for this.
Example one for 10ms depending what area of holdoff need use in work.
Of course this is not best possible solution for working ergonomy. This "multipurpose" knob speed up system is not best possible. Fast turning increments may be better selected for fast adjusting.
Here example from expensive (old) professional class Tektronix.
First in menu there can find holdoff. It can adjust just from 0-100 on its own undimensioned scale. Nothing on the screen tell what is holdoff time. Take user manual. It do not help. Exept that it tell it can change using control knob between 0-100. It is really "clever" user manual.
But user manual give one wink where can find more information.
Ok after time this very clear most deep imformation can find. This is most detailed information what can find. Ok... these are "limits". It is fast to turn from 0-100. How long time you need with HP48GX to solve what is holdoff time if you turn knob to example value 57 and you have 1us/div but in Tektronix case it is of course M 1us (all know what is M 1us) horizontal speed. (other question is that who need know exact holdoff time in practice)
But here in picture most deep information what can get from Tektronix TDS5xxA series.
Made in China?:
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There is now available unofficial DIY version (it is preliminary version 2b) for this "Noisy GND" issue.
First published modify for Adapter card (PCB Version: SDS7102_CON_3.2). (http://owon.forumup.com/viewtopic.php?t=159&mforum=owon)
Owon is now working for final version for production asap.
Of course there may be better result becouse they may (if need) also change PCB layout for example better handling for parasitic inductances and capasitances.
This preliminary version 2b modification include:
Adapter board modification:
- TFT backlight LED driver SMPS (it was very bad and also this RF EMI noise radiate all around via to TFT panel)
- +5.5V SMPS (it was bad)
- +3.3V SMPS (it was slightly bad)
(Adapter board modification need good tools for SMD rework! Do not even try with cheap crap "noname" soldering(desoldering tools. It can only destroy components and board itself. It need real fast thermal transfer power without adjustable "overheating" iron. Also preheating helps.)
PSU board modification (DIY version 2b coming soon after some stress test):
(also version 2b is not yet enough good in situation where battery installed AND battery is charging same time when use oscilloscope, still 8.4V produce too much RF noise.)
- +8.4V main SMPS (it was bad without battery and very very bad if battery is charging + oscilloscope in use))
- -7.6V SMPS (it was very bad)
PSU board is much more easy for DIY. It is single side board. (mixed with SMD and through-hole)
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I just stumbled upon a new download on Owon's site. It's called Labview opearation cases for SDS series and is under driver download.
It contains the USB driver .dlls, some Labview files for interfacing scopes with it (I don't use Labview, so I don't know how useful they are) and a new and more detailed version of OWON Oscilloscope PC Guidance Manual (it's 1.3 now). At first look, it seems much more detailed than the previous version 1.1 which is currently circulating the Internet. There are examples for USB and serial interfacing and a few mentions of LAN. Anyway, it looks like the main focus here was USB.
Hopefully this will allow creation of better PC side software than what we currently have.
As a side-note, the guidance manual file is actually called "application notes_en.doc", but is referred to as "OWON Oscilloscope PC Guidance Manual.doc" by the readme file.
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There is now available unofficial DIY version (it is preliminary version 2b) for this "Noisy GND" issue.
First published modify for Adapter card (PCB Version: SDS7102_CON_3.2). (http://owon.forumup.com/viewtopic.php?t=159&mforum=owon)
Owon is now working for final version for production asap.
Of course there may be better result becouse they may (if need) also change PCB layout for example better handling for parasitic inductances and capasitances.
This preliminary version 2b modification include:
Adapter board modification:
- TFT backlight LED driver SMPS (it was very bad and also this RF EMI noise radiate all around via to TFT panel)
- +5.5V SMPS (it was bad)
- +3.3V SMPS (it was slightly bad)
(Adapter board modification need good tools for SMD rework! Do not even try with cheap crap "noname" soldering(desoldering tools. It can only destroy components and board itself. It need real fast thermal transfer power without adjustable "overheating" iron. Also preheating helps.)
PSU board modification (DIY version 2b coming soon after some stress test):
(also version 2b is not yet enough good in situation where battery installed AND battery is charging same time when use oscilloscope, still 8.4V produce too much RF noise.)
- +8.4V main SMPS (it was bad without battery and very very bad if battery is charging + oscilloscope in use))
- -7.6V SMPS (it was very bad)
PSU board is much more easy for DIY. It is single side board. (mixed with SMD and through-hole)
Thanks again for all the investigation. So what's the plan for Owon to fix scopes under warranty? What should I be telling my distributor? I could DIY, but would rather have the redesigned boards from the factory and not risk voiding my warranty.
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I also do not have the necessary tools or experience to carry out SMD repairs. It would be easier to receive a replacement card from Owon. Do we have any news from them?
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I'm also interested in this!
Is there any response from Owon? Is there even information about no response? Any new hardware revisions?
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Hi guys,
I'm thinking about getting my first scope (the owon 6062) and I was about to pull the trigger on it, but I just wanted to ask if anyone knows if the 6062 suffers from the same ground noise problem as the 7102? I'm very much a beginner with electronics but ground noise sounds like something serious and best to avoid? Im also not very confident reworking smd :D
Thanks for your help!
Paul
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In my very simple opinion and comparing with an old analogue scope, the OWON SDS 7102V is incapable of displaying a trace of a small amplitude, it even has troubles with +/-100mV - locking on will be problematic and there will be noise spikes almost obliterating the signal.
There may be a "fix" on the way, not least due to the contribution of a few members of this board, but it will require DIY skills even if OWON decide to ship replacement "adapter" boards.
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Thanks Akis, so does the problem include the 6062 as well?
Cheers,
Paul
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Well, wait a few months, or if you want your scope today, go and buy a cheap GW Instek or Rigol. They will not have the 2×10MB acquisition memory, but who cares. :-BROKE
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2 comments/questions
1). I do not remember seeing it mentioned, but, is the Owon "noisy GND" issue similar in nature as Rigol's as mentioned somewhere in eevblog. Maybe all scopes of the same class have this problem? Can anyone verify?
2). If the DUT is some distance away from the Owon, the noise is way less, right? If true, I do not really see it is a big problem.
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My speculation could be wrong, but I think that the issue currently discussed would affect most of the SDS series, since it appears to be caused by components that would be most likely common to the whole series.
Since the problem is caused by EM radiation from components, it would be reasonable to expect the "noise" to drop with distance, but that leaves the other side of the issue:
How are we going to measure precisely what's happening? For long distance measurement we'd need probes with long cables and the cables themselves are going to affect measurement. I'm looking right now at manual for Testec's TT-LF series probes and for example the probe with 1.2 m cable has 150 MHz bandwidth, the 1.6 m cable probe has 130 MHz bandwidth and the 2.0 m probe has 100 MHz bandwidth.
The other option would be to go through the trouble of placing dedicated BNC connectors or probe testpoints on the PCB in order to avoid the radiation, but I suspect that such measures could easily be overkill for users of scope such as SDS7102.
This leaves us with the springy ground lead accessory which ships with the scope probes, but it's a bit awkward to use and isn't all that durable. On the other hand, they are relatively easy to make.
So perhaps it would be best to wait until next revision ships and get a unit of that revision.
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1). I do not remember seeing it mentioned, but, is the Owon "noisy GND" issue similar in nature as Rigol's as mentioned somewhere in eevblog. Maybe all scopes of the same class have this problem? Can anyone verify?
I think you're referring to a thread that was started because of a particular problem that one member (A Hellene) was having with his Rigol DS1052E. But I think there are tens (or hundreds) of thousands of Rigol users without significant noise problems.
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NEWBIE and POTENTIAL OWON CUSTOMER
Hello -- I'm very interested in the Owon SDS7102 and was about to buy it on Ebay, and after seeing the problem, I decided to wait until the problem is fixed (Thanks to everyone in the forum especially the "Improvers and Tinkerers".
A couple of questions:
1. Is there a list of outstanding issues posted somewhere for tracking and
2. For each issue, what kind of functions will it adversely affect, or is it an overall showstopper?
Something on the lines of a vehicle -- I want to buy a vehicle, but if there are 2 issues P1) Leaking Roof P2) Problematic 4WD mode, I could understand if I wanted to buy the vehicle NOW, I could P1) Avoid driving on rainy season and P2) Do not use 4WD mode. That, or should I wait for the complete fixes from manufacturer.
Thanks in advance.
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Well I am no expert oscilloscope reviewer, and this is what I have found out so far:
1) Low voltage signals are affected by all the noise sources inside the scope as mentioned in the pages above, anything below +/-0.5V pk is problematic.
2) MATHS and MEASUREMENT seems to work from what is displayed on the screen. It seems that the scope has two memory areas: one is what it captures (raw data) and he second memory area is what it displays on the screen. Maths and measurements are derived from the screen data, it seems, which is a very bad idea. Quick example: take two sinusoidal signals, one is 50V pk, the other is 48V pk. The difference is 2V pk, and this is what the MATHS will display. However this 2V curve is almost a flat line when you are also displaying a 50V, ie the division is 10V. There is nothing you can do to "zoom in" on the MATHs curve, because this will take the other two curves out of range and you will get garbage on the screen.
3) fan makes constant and annoying noise - wondering if it could be variable speed like on my laptop :-)
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Maths and measurements are derived from the screen data, it seems, which is a very bad idea.
Perhaps - but from what I understand, it's standard operating procedure for virtually all low to mid-range DSOs (e.g. the Agilent InfiniVision X series does the same).
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The example I have above was not theoretical, I was really trying to measure the voltage drop across a known resistor and it was 1-2V out of 60V. It is very hard to read the MATH curve under those conditions.
In my opinion there should be an option to hide ch1 and ch2 when in Maths so the screen does not get cluttered, and also to measure and zoom on the Maths curve, which would necessitate new software I suppose.
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Well I am no expert oscilloscope reviewer, and this is what I have found out so far:
1) Low voltage signals are affected by all the noise sources inside the scope as mentioned in the pages above,
anything below +/-0.5V pk is problematic.
This problem is in your Owon becouse you are one who have this most bad noisy GND issue.
Here is some pictures from factory new Owons and mesurments made so that it really show worst. Oscilloscope run with mains power (not with battery)
Probe connected to signal with its own GND wire with alligator. Oscilloscope is in normal enviroment and signal source is also connected to mains power.
Scope and signal source are so that common mode noise picked up from equipments itself and from enviroment is as bad as it is typically and also connected to laptop so that situation is as bad as can be if think what kind of "antenna" this whole test setup is.
20mVpp do not look very problematic. There is connection with normal GND wire and then with short GND spring what is very normal practice if people have any real experience about measurements and for avoid problems.
(also it is very good to look this youtube from Dave where he hanging around Rigol DS2202 and common mode noise.
Look what happend there related to Rigol TFT. (yes Owon do same)
Look carefully. There is some very "fun" details.
Specially starting after 13.30. (TFT)
Also 17.38 is short very interesting point. Coaxial cable near Rigol TFT.
But these pictures attached show how it is here and related problems under +/-0.5Vpp signals as you tell. My opinion is that it is not very problematic. And methods and settings I use for these are just these "entry level" practices where all conncted as "magpie nest".
Some reader may see more and some may see less problems.
2) MATHS and MEASUREMENT seems to work from what is displayed on the screen. It seems that the scope has two
memory areas: one is what it captures (raw data) and he second memory area is what it displays on the screen.
Maths and measurements are derived from the screen data, it seems, which is a very bad idea. Quick example: take
two sinusoidal signals, one is 50V pk, the other is 48V pk. The difference is 2V pk, and this is what the MATHS
will display. However this 2V curve is almost a flat line when you are also displaying a 50V, ie the division is
10V. There is nothing you can do to "zoom in" on the MATHs curve, because this will take the other two curves out
of range and you will get garbage on the screen.
There is 2pcs 8bit (*1) ADC's
((*1) and then note all things in practice what reduce conversion result quality)
It is good to understand this simple math.
Data for math is 8bit. What happend if in one point result is 120-120 and then next place 122 - 120.
Difference between these is 2. There is 4 pixels vertically. Yes you can zoom it. Where is now more information if you have nearly half div for one resolution step. Zoom can not add resolution!
For my eyes some times zoom factor 2 or 4 is enough for better visibility if difference is quite small. (btw. how it differ in vertical direction from raw vector data in practice?)
In picture I have zoomed by 10x (inputs 2V/div and math 200mV/div)
It is different case if we have more resolution than 8bit and then we have lot of less resolution in display. Now our display resolution is more (double) than data resolution.
Look these example pictures.
3) fan makes constant and annoying noise - wondering if it could be variable speed like on my laptop :-)
Do you know what this price class oscilloscope have more silent fan? If there is fan.
I know one. Siglent but difference is very marginal.
But in other hand, time ago Owon have some extra problems with fans. Many fans was assembled wrong and / or damaged in assembly in factory and after short time or just new from package make very very bad noise.
These fans need change.
Pictures (picture names give some explanation also)
First 2 pictures for this Math "zoom"
and then some pictures related to: "anything below +/-0.5V pk is problematic."
In some pictures these is Acquire mode PEAK. If filename read acqN there is Normal mode.
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1) I do not have those two extra options on my maths functions - vertical position and V/div. I updated to the latest software 4-5 months ago. I am glad that they added that feature though, and I hope it is software and not hardware changes, so I can get it too.
2) Both Maths and Measurement display garbage if the signal exceeds the screen size, ie if you have selected a smaller V/div so that CH1 or CH2 (or both) curves do not fit. I understand what you mean about the ADC being 8 bit and the screen vertical resolution being almost twice as large.
3) Since these changes seem to be software related, could you please ask them to add a "Maths measurement" function too? Currently you can measure CH1 and CH2 but not the resulting Maths curve, and it is easier to read a number off the screen than try to count divisions etc.
4) My Owon may be more "noisy" than yours because as I have said earlier on in this thread it has problems with anything less than 0.5V pk. I was the one that started this discussion if you recall. Are you using your "DIY fixed" Owon ? Can we try some of the fixes you and others have attempted to reduce the noise or should we wait for an official reply from Owon? Last you had said it was Chinese New Year and the Owon factory was closed.
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Maths and measurements are derived from the screen data, it seems, which is a very bad idea.
Perhaps - but from what I understand, it's standard operating procedure for virtually all low to mid-range DSOs (e.g. the Agilent InfiniVision X series does the same).
Based on another comment on another thread where I was informed a the 500 UK pound "Agilent" and "Tektronix" were simply re-badged cheap Chinese scopes, how do we know which "Agilent" is actually the real thing?
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4) My Owon may be more "noisy" than yours because as I have said earlier on in this thread it has problems with anything less than 0.5V pk. I was the one that started this discussion if you recall. Are you using your "DIY fixed" Owon ? Can we try some of the fixes you and others have attempted to reduce the noise or should we wait for an official reply from Owon? Last you had said it was Chinese New Year and the Owon factory was closed.
Yes, this is case. You have more noise as told earlier. Of course I remember this becouse after this start heavy hunting to find problems and solution.
I take two random factory new owon from original new factory package just to my table and look they are just same related to this noise issue. Then I randomly take other one and do these tiny tests and images.
This is NOT from my prototype DIY.
From my prototype DIY I have made documentation for Owon. (This proto is totally disassembled on my workshop table for more deep experimentals)
I have talked with OWON after the holiday period.
Owon answer about "DIY" was that they accept it IF I do it to my customers, in this case it do not void warranty (as described in other place).
Owon have also told (time ago) that they transfer this to production asap (they take something from me and something how they do. What is asap: They need do they own tests and becouse they need also made new PCB's and so they can also do it littlebit different (I hope they do better than my DIY). In mass production it is not so fast to make changes you know. Design, protoboards, tests, possible changes, protoboards, tests... iteration as many times as need.. then order PCB's and components to production line.. it take absolute minimum least one month. In practice perhaps 2.
(It is fun, I have tested very very old Owon and there is not at all this extra "noisy GND" problem.
And more fun is that circuits are very very same.)
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Based on another comment on another thread where I was informed a the 500 UK pound "Agilent" and "Tektronix" were simply re-badged cheap Chinese scopes, how do we know which "Agilent" is actually the real thing?
There is tons of information around about the completely in-house designed Agilent InfiniiVision X series - including Dave's reviews and teardowns. Suffice it to say, if you spent $15,825 for the top of the line Agilent MSOX3104A 1 GHz Oscilloscope with 4 Analog and 16 Digital Channels - you would still be making measurements on the displayed data - and not the actual sample data. I believe (higher-end?) Tektronix DSOs (and perhaps Hameg?) make measurements in sample memory.
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2) Both Maths and Measurement display garbage if the signal exceeds the screen size, ie if you have selected a smaller V/div so that CH1 or CH2 (or both) curves do not fit.
Yes becouse in Owon, ADC whole vertical data range is nearly equal to display 10 divs (500 vs 512)
In my old tek workhorse it display 8 div and if I remember right (not so exactly) it show something like 200 ADC values on the screen. So signal can go maximum 56 over screen border.
About this measurement fronm display. What make it less accurate as long as display resolution is much more than raw data.
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1) I do not have those two extra options on my maths functions - vertical position and V/div. I updated to the latest software 4-5 months ago. I am glad that they added that feature though, and I hope it is software and not hardware changes, so I can get it too.
Currently newest software versions are 2.8.2 from 2012-12-30 and 2.8.1.6 from 2012-11-05, depending on serial number. Also it appears that there was firmware version 2.8.1 which was removed from their site for some reason.
If you can, try the newest firmware and report back. I think I didn't see (or at least notice) the math divisions option on my scope with 2.6.2 hardware and 2.8.2 firmware. I could be wrong but I can't check since the scope is currently being repaired.
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2.8.3 is newest. (and this is first verion where this scale and position is added for math menu )
Perhaps soon it come also available for free download.
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In my old tek workhorse it display 8 div and if I remember right (not so exactly) it show something like 200 ADC values on the screen. So signal can go maximum 56 over screen border.
Same as the Rigol DS2000s (200 bits -> 10 divs @ 400pixels), although strangely, the DS4000s map the entire 256 bits to the display (I'm wondering if the change is related to the DS2000's extra 500uV range?). I have mixed-feelings about this practice - on one hand, it gives you a little headroom when making measurements, etc - but otoh, you sacrifice vertical resolution.
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CURRENT SDS7102 ISSUES
Akis, thanks for the recap on the "Issues".
OWON REALITY "SHOW OF QUALITY"
rf-loop, I must admit this is the first time in my life I'm experiencing "National Geographic style Reality Show -- from customer review (marmad)+ feedbacks(everyone) + replies (you, etc) + to factory floor and back!" I think it really gives customers/ potential customer a very good feel and trust in the Owon brand that -- there is a listening channel with capable technical support to get customers through problems. And it looks like if alot of things discussed were implemented, Owon would have a very strong and impressed group of people ready to say good things for the company. I really want to see a great Finale to the Show! (I just arrived upon just entering into the electronics arena).
Having been in the IT industry for some time, I really think Owon should take their time to stress test the new board so that old issues do not resurface and every bit of 'critical items' plus 'inexpensive and easy to do' that address the hardware root cause are certainly done right before shipment (as rf-loop said maybe up to 1 or 2 months). Maybe then 'practical firmware features' can come out later.
Marmad, thanks for starting the review. I (and most certainly those newbies out there) never knew Owon before and because of your review I know the company -- I hope Owon sends you free oscilloscopes for life! I have a feel you have good inputs and if Owon were smart theyd send you stuff to test :>
Marmad, how's the Rigol 2072? Do you have a link for further reviews/ how its going, is 70Mhz good enough for the long term/etc? I planned to do what you had said - use the Owon first and if it gets serious, to get more powerful stuff later (either Owon or others)... However, I'm not sure how I can start learning electronics WITHOUT an oscilloscope (if SDS7102 will be ready in a Month or Two); Is there something I can start by using the audio port of a PC I can do while waiting?
Thanks again guys :>
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Marmad, thanks for starting the review. I (and most certainly those newbies out there) never knew Owon before and because of your review I know the company -- I hope Owon sends you free oscilloscopes for life! I have a feel you have good inputs and if Owon were smart theyd send you stuff to test :>
@kuson - Your welcome - and thanks for the show of support. But I think rf-loop would disagree about whether I should get free stuff from Owon :D As you might know, I don't own an Owon at the moment, although if I had extra money for a second inexpensive DSO, I'd probably get an SDS7102 to have something that was battery-operated (with VGA out) for the occasional times when that would really be handy. But most of your gratitude should be directed at rf-loop for his tireless support of the Owon users here - many of whom are not even customers of his. I know he sells the DSOs, but he has gone above and beyond what was required in helping people.
Marmad, how's the Rigol 2072? Do you have a link for further reviews/ how its going, is 70Mhz good enough for the long term/etc? I planned to do what you had said - use the Owon first and if it gets serious, to get more powerful stuff later (either Owon or others)... However, I'm not sure how I can start learning electronics WITHOUT an oscilloscope (if SDS7102 will be ready in a Month or Two); Is there something I can start by using the audio port of a PC I can do while waiting?
I'm still enjoying the Rigol very much - but it's not without it's problems (biggest for me is the inability to read sample memory reliably from the PC) - most of which could be fixed with a firmware update (but will they?) - which, typically, is about 3 or 4 months overdue from Rigol. OTOH, bugs in the current firmware allow you to keep the expensive trial options continuously - so perhaps it's good they're late :) I don't make a huge amount of money so it was rather painful to buy it - but if you want a DSO with a fast enough update for intensity grading (which is really handy), I think it's still the best bargain (although the new GW-Intek 2000 series is a contender). As far as the 70MHz goes - well, I'll just say that, like older Rigols, they have the ability to reach beyond their "limits" ;) I don't know if you saw the review here (https://www.eevblog.com/forum/testgear/first-impressions-and-review-of-the-rigol-ds2072-ds2000-series-dso/), but the same post (at the bottom) also lists all of the current bugs the users at EEVBlog have discovered in the current version of firmware. I've also been working on software utilities for the Rigol, which are posted in this thread. (https://www.eevblog.com/forum/projects/software-tips-and-tricks-for-rigol-ds200040006000-ultravision-dsos/)
Edit: BTW, rf-loop should be able to keep you informed about when Owon may resolve the current issues - and it would be good to buy.
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GDS-2000A has some minor bugs, too. https://www.eevblog.com/forum/testgear/gds-2000a-new-economic-oscilloscope-by-gw-instek-comes-to-market/ (https://www.eevblog.com/forum/testgear/gds-2000a-new-economic-oscilloscope-by-gw-instek-comes-to-market/)
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CURRENT SDS7102 ISSUES
Akis, thanks for the recap on the "Issues".
OWON REALITY "SHOW OF QUALITY"
rf-loop, I must admit this is the first time in my life I'm experiencing "National Geographic style Reality Show -- from customer review (marmad)+ feedbacks(everyone) + replies (you, etc) + to factory floor and back!" I think it really gives customers/ potential customer a very good feel and trust in the Owon brand that -- there is a listening channel with capable technical support to get customers through problems. And it looks like if alot of things discussed were implemented, Owon would have a very strong and impressed group of people ready to say good things for the company. I really want to see a great Finale to the Show! (I just arrived upon just entering into the electronics arena).
Having been in the IT industry for some time, I really think Owon should take their time to stress test the new board so that old issues do not resurface and every bit of 'critical items' plus 'inexpensive and easy to do' that address the hardware root cause are certainly done right before shipment (as rf-loop said maybe up to 1 or 2 months). Maybe then 'practical firmware features' can come out later.
Marmad, thanks for starting the review. I (and most certainly those newbies out there) never knew Owon before and because of your review I know the company -- I hope Owon sends you free oscilloscopes for life! I have a feel you have good inputs and if Owon were smart theyd send you stuff to test :>
Marmad, how's the Rigol 2072? Do you have a link for further reviews/ how its going, is 70Mhz good enough for the long term/etc? I planned to do what you had said - use the Owon first and if it gets serious, to get more powerful stuff later (either Owon or others)... However, I'm not sure how I can start learning electronics WITHOUT an oscilloscope (if SDS7102 will be ready in a Month or Two); Is there something I can start by using the audio port of a PC I can do while waiting?
Thanks again guys :>
I can't speak for the other Owon SDS owners, but I won't have a "warm and fuzzy" feeling for Owon until I see an official acknowledgement of the ground noise issue and an offer to fix the scopes under warranty. It may be a "cheap" scope, but it wasn't free and I do expect a certain degree of engineering to go into a product being sold to engineers. Not being able to measure low level signals with the supplied probes is not acceptable - I don't care how cheap the instrument is. We can debate usability issues, fan noise, durability, etc. but we are talking about the basic ability to meet specs and serve the fundamental purpose the instrument was designed for. If they don't repair these then they can pretty much kiss their reputation goodbye because the Internet never forgets and real businesses will stay away from a supplier that does not stand by their products - especially test & measurement equipment.
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I can't speak for the other Owon SDS owners, but I won't have a "warm and fuzzy" feeling for Owon until I see an official acknowledgement of the ground noise issue and an offer to fix the scopes under warranty.
I would not bet on warranty repair either. More likely strategy is to sweep the case under carpet and hope that everyone forget...
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I can't speak for the other Owon SDS owners, but I won't have a "warm and fuzzy" feeling for Owon until I see an official acknowledgement of the ground noise issue and an offer to fix the scopes under warranty.
I would not bet on warranty repair either. More likely strategy is to sweep the case under carpet and hope that everyone forget...
Well, I'm not sure it's fair to say that at this point - as far as I know, Owon has been pretty responsive in the past about resolving technical problems with the SDS line to their customers' satisfaction. But an official acknowledgement? I had to burst out laughing at that one! I'm really not trying to insult you here, but I'm guessing you haven't had much experience with Chinese companies.
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Well, SDS series is not a new product, it is sold from 2011. I would expect less problems, then it has. :(
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Well, SDS series is not a new product, it is sold from 2011. I would expect less problems, then it has. :(
But many products that have been on the market for awhile occassionally suffer from new, unforeseen problems caused by design changes or manufacturing defects. That's why some companies have 'recall's of items (cars, laptops, food items, etc, etc) - because some new problem has arisen in an often older product.
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I've just picked up an SDS7102v and would like to thank you all for the beta testing before I parted with the folding stuff.
Cheers lads.
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I ordered the owon sds6062 decided to "roll the dice" with it. Still not sure if it suffers from the same problem, but when i get it (couple of weeks) ill let you guys know if its got the same issue as the 7102. I hope not :(
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I ordered the owon sds6062 decided to "roll the dice" with it. Still not sure if it suffers from the same problem, but when i get it (couple of weeks) ill let you guys know if its got the same issue as the 7102. I hope not :(
Don't you have any companies in Australia like Batronix - that offer a trial period (http://www.batronix.com/shop/oscilloscopes/Owon-SDS6062.html)? I bought the Rigol DS1052E from them - then returned it when I wasn't happy with it. It just cost me the €12 to ship it back to them.
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Maybe there is, but none that i know of marmad.
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Maybe there is, but none that i know of marmad.
Well I noticed that in the thread that you started, hammil advised you:
Buy it from a reputable dealer, communicating with them the fact that if you do get this issue, you'll want to get a working replacement or refund.
And this was very good advice. If you discussed it with the dealer beforehand, it would be easy to return (or expect a replacement) after trying it. It may have required spending a little more (for a reputable dealer) - but in this case, IMO, it would have been worth the peace of mind.
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Good advice, but alas it was from a non-reputable dealer (not sure there are any in oz that sell the 6062?) and i forgot to mention the issue when i bought it! Oh well, lets wait and see if it has the issue first.
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I can't speak for the other Owon SDS owners, but I won't have a "warm and fuzzy" feeling for Owon until I see an official acknowledgement of the ground noise issue and an offer to fix the scopes under warranty.
I would not bet on warranty repair either. More likely strategy is to sweep the case under carpet and hope that everyone forget...
Well, I'm not sure it's fair to say that at this point - as far as I know, Owon has been pretty responsive in the past about resolving technical problems with the SDS line to their customers' satisfaction. But an official acknowledgement? I had to burst out laughing at that one! I'm really not trying to insult you here, but I'm guessing you haven't had much experience with Chinese companies.
No offense taken - I haven't had much experience with Chinese manufacturers, but I am learning rapidly. I find this whole affair to be an interesting learning experience. I'll be pretty unhappy if they don't offer a solution to current owners, but I'll just move on and never buy from or recommend them again. I find the total lack of QC or product testing to be pretty amusing since those are the worst corners to cut if you are trying to break into a new segment of the test and measurement market.
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So I just got an Odon SDS7102 with version 2.8.3 firmware, it has the 100mV GND noise on both channel 1 and 2 but so far that hasn't bothered me as I will probably never need to measure signals anywhere less than a volt for my applications. The only thing I can't figure out is why the damn thing just hangs when I attempt to capture the screen as a image on a flash drive. I can disconnect the flash drive and it'll go back to normal but looking at what it ends up writing on the drive, it's just a 0KB file. I can leave it sitting for more than necessary like 5 minutes and it won't save anything, it just sits there frozen.
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The only thing I can't figure out is why the damn thing just hangs when I attempt to capture the screen as a image on a flash drive.
Is the drive formatted to FAT-32?
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Also check cluster size on the drive. If I remember correctly, this scope needs 4 KiB clusters (allocation size 4096 on Windows format options) to work. If the drive is large, it may use bigger clusters by default which can cause described problems.
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No offense taken - I haven't had much experience with Chinese manufacturers, but I am learning rapidly. I find this whole affair to be an interesting learning experience. I'll be pretty unhappy if they don't offer a solution to current owners, but I'll just move on and never buy from or recommend them again. I find the total lack of QC or product testing to be pretty amusing since those are the worst corners to cut if you are trying to break into a new segment of the test and measurement market.
To be fair to Owon, I doubt there's a company on the planet that wants to publicly acknowledge mistakes. But the Chinese in particular seem to feel the need to be reticent - or to redefine a mistake as a 'misinterpreted choice'. Anyway, I hope you and the rest of the owners stuck with this problem will get some resolution from Owon.
But, as a sidebar, It is interesting to note what seems to be happening in the DSO market over the last two years - beginning with the Agilent X series. Before then it seemed that to make the step from a low-end DSO to one with much better signal capabilities and more advanced features - required a much bigger outlay of money. But now it appears that this gap is shrinking faster than ever, and the difference in quality one gets at each new price point begins to get much higher. It will be interesting to see how this all plays out in the next few years.
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So I just got an Odon SDS7102 with version 2.8.3 firmware, it has the 100mV GND noise on both channel 1 and 2 but so far that hasn't bothered me as I will probably never need to measure signals anywhere less than a volt for my applications. The only thing I can't figure out is why the damn thing just hangs when I attempt to capture the screen as a image on a flash drive. I can disconnect the flash drive and it'll go back to normal but looking at what it ends up writing on the drive, it's just a 0KB file. I can leave it sitting for more than necessary like 5 minutes and it won't save anything, it just sits there frozen.
Use a smaller size USB drive, it cannot handle the big ones. yet another bug :)
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So I just got an Odon SDS7102 with version 2.8.3 firmware, it has the 100mV GND noise on both channel 1 and 2 but so far that hasn't bothered me as I will probably never need to measure signals anywhere less than a volt for my applications. The only thing I can't figure out is why the damn thing just hangs when I attempt to capture the screen as a image on a flash drive. I can disconnect the flash drive and it'll go back to normal but looking at what it ends up writing on the drive, it's just a 0KB file. I can leave it sitting for more than necessary like 5 minutes and it won't save anything, it just sits there frozen.
Use a smaller size USB drive, it cannot handle the big ones. yet another bug :)
It's a miniature 16GB drive in a solid metal cast body which I use because shitty plastic ones always fall apart on me. If the scope cannot handle 16GB drives then this is truely a deal breaker to me.
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Have you tried the other suggestion, stick the USB drive into your PC and format it with FAT32 and 4KB Allocation Unit Size. Maybe this will work.
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It's a miniature 16GB drive in a solid metal cast body which I use because shitty plastic ones always fall apart on me. If the scope cannot handle 16GB drives then this is truely a deal breaker to me.
It is very clear and it is not any kind of bug:
In Owon User manual: The supported format of the USB disk: FAT32 file system, cluster size cannot exceed 4K.
Then Microsoft:
http://support.microsoft.com/kb/140365 (http://support.microsoft.com/kb/140365)
Default cluster size for NTFS, FAT, and exFAT
Article ID: 140365
Image about FAT32 part of article
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It's a miniature 16GB drive in a solid metal cast body which I use because shitty plastic ones always fall apart on me. If the scope cannot handle 16GB drives then this is truely a deal breaker to me.
It is very clear and it is not any kind of bug:
In Owon User manual: The supported format of the USB disk: FAT32 file system, cluster size cannot exceed 4K.
Then Microsoft:
http://support.microsoft.com/kb/140365 (http://support.microsoft.com/kb/140365)
Default cluster size for NTFS, FAT, and exFAT
Article ID: 140365
Image about FAT32 part of article
They should add in drive size instead of saying 4KB cluster size in their manual. Most people won't know off the top of their heads what that correlates to.
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It's a miniature 16GB drive in a solid metal cast body which I use because shitty plastic ones always fall apart on me. If the scope cannot handle 16GB drives then this is truely a deal breaker to me.
It is very clear and it is not any kind of bug:
In Owon User manual: The supported format of the USB disk: FAT32 file system, cluster size cannot exceed 4K.
Then Microsoft:
http://support.microsoft.com/kb/140365 (http://support.microsoft.com/kb/140365)
Default cluster size for NTFS, FAT, and exFAT
Article ID: 140365
Image about FAT32 part of article
They should add in drive size instead of saying 4KB cluster size in their manual. Most people won't know off the top of their heads what that correlates to.
There's no sense in setting the value in drive size since you can format the drive and set manually the cluster size. Cluster size isn't all that related to drive size (yes, I'm aware that there are performance concerns with related to number of clusters and so on).
FAT32 supports up to 268_435_445 clusters. If cluster size is the only limitation, then the highest capacity which the scope should be able to read is 1023 GiB*, which is quite a bit bigger than the sizes we're talking about here.
What's the big deal about formatting the flash drive so that it has appropriate cluster size?
*I forgot to take into account maximum FAT size during that calculation, so maximum drive could be smaller, but in any case clusters are not the limiting point here.
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I just upgraded my SD7102 to 2.8.3 firmware and the 2.0.8.13 PC oscilloscope software. Everything seems to work properly except the Image and High Memory Depth transfer if I connect via LAN. However WaveForm transfer and Remote Control (in Waveform transfer) work fine. If I connect via USB everything works correctly. I've tried going back to earlier versions of the PC oscilloscope software and connecting the SD7102 directly to the PC via LAN, but I still get the same error for Image and High Memory Depth transfer when connected via LAN. At this point I suspect that this may be a bug in the new firmware. I wish I had tried the LAN feature with the 2.8.2 firmware, but I never got around to it until after the upgrade. Has anybody else ran into this issue? Any ideas will be appreciated!
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With scope connected directly to the PC, try setting the duplex manually to full duplex and try to transfer image or full memory. To me this seems like an issue that could possibly be related to duplex detection. It will look like it works fine for short transfers, but can start to act strange for longer transfers.
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With scope connected directly to the PC, try setting the duplex manually to full duplex and try to transfer image or full memory. To me this seems like an issue that could possibly be related to duplex detection. It will look like it works fine for short transfers, but can start to act strange for longer transfers.
Thanks for the tip. I manually changed the duplex to full but still get the same error, I also tried changing other Ethernet Controller options like flow control and receive buffer size without success. One other thing that makes me suspect a firmware bug is the content of the Get Data dialog during image transfer. When connected via USB it shows a File Type: bmp and the field used for file size shows 1406kB. However, when connected via LAN it shows File Type: bin and file size 111212kB. The progress field updates for a while and stops at 1406kB, which means to me that the image file was probably fully transferred. But it seems that the PC software is still waiting for the rest of that 111212kB file size and after a while timeouts and emits an error window.
For full memory transfer the situation is a little different. If connected via USB it shows File Type: bin, the file size field has a ?, and the progress field is about 19531kB when the transfer ends. If connected via LAN the File Type and file size fields remains blank and the progress field has 0B. At this point the SDS7102 is frozen and has to be turned Off/On before I can do anything else. In the mean time the PC software timeouts and emits the error window. It seems to me that when the PC software sends the full memory transfer command to the DSO via LAN it causes it to freeze and of course nothing is received by the PC software so it times out.
I'm really curious if anybody else has this problem or if it's just me.
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Yes I have tested it shortly. It looks like there is added bug in new (2.8.3.) FW.
(I hope they do not start "hantek process" where one fix generate two new problem.)
After I have documented problem I will also send note to Owon.
It is good if also some others do same.
Also in China, there is starting holiday time (Qing Ming Jie) 4. - 6.Apr.
So these days there may be delays in answers. (rush + holiday)
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Yes I have tested it shortly. It looks like there is added bug in new (2.8.3.) FW.
(I hope they do not start "hantek process" where one fix generate two new problem.)
After I have documented problem I will also send note to Owon.
It is good if also some others do same.
Also in China, there is starting holiday time (Qing Ming Jie) 4. - 6.Apr.
So these days there may be delays in answers. (rush + holiday)
Thanks for confirming my suspicion. I left a message at OWON's web site explaining the situation. I also have the GND noise problem but I didn't mention that since I'm sure they are well aware of the situation. In the mean time I'm using 3" ground wire instead of the 6.5" wires that came with the probes. This makes quite a difference if you are trying to see signals under .5V. Of course I use the spring grounds when possible, but some times there is no way to get a ground this way.
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Hello all,
I am new to this forum and this is my first post. I have been looking at purchasing a Owon SDS7102V scope and ready to order it but then I paused after reading about the "video trigger jitter" and "ground noise problem" in this scope.
I contacted my local dealer (Saelig) with the following question and received the following answer along with waveform captures. It looks to me like the GND noise problem is resolved.
What is your opinion? I am new to DSOs so I am unsure if my conclusion is justified by the screenshots provided by the dealer.
**** Begin question to dealer ****
I want to purchase the Owon SDS7102V oscilloscope but I am concerned about the following two manufacturing defects. Have these been fixed? If I get a scope tomorrow will it continue to have the same problems?
Video trigger jitter
Owon SDS7102V Video signal (https://www.youtube.com/watch?v=yNDevL2KDDU#)
http://owon.forumup.com/about153-0-asc-15-owon.html (http://owon.forumup.com/about153-0-asc-15-owon.html)
Noisy GND problem
http://owon.freeforums.org/under-work-about-gnd-noise-t21.html (http://owon.freeforums.org/under-work-about-gnd-noise-t21.html)
owon 7102 gnd noise (https://www.youtube.com/watch?v=6bKDudV2d0E#ws)
**** End question to dealer ****
**** Begin reply from dealer ****
I took a look at both of the links concerning the jitter associated with video trigger. I also set up an inexpensive camera having an NTSC output for a test.
What I found as that there is jitter on the order of about 1us with the source I used. This is what I used – the MV401TV-N unit, which sells for about $60. http://www.saelig.com/product/VI024.htm (http://www.saelig.com/product/VI024.htm)
The next question I would ask is about the jitter associated with the source. I don’t have a high-quality reference with which to compare. However, the signal itself is sufficiently stable to work with, and, if a critical measurement must be made, all one has to do is depress the Run/Stop key and freeze the image.
On the other hand, perhaps this is an opportunity for improvement for Owon, and I’ll pass the issue along to my factory contact.
While we’re discussing jitter, you should know that the timebase jitter and inter-channel skew for the Owon is very low. I’ve attached three screen captures of a 10MHz squarewave, where the trigger is on the falling edge. Channel 1 trace (in red) is shown with infinite persistence turned on – each minor division is 400ps. Similarly, the inter-channel skew is <200ps. Incidentally, the Tabor generator is specified at <2ps.
The frequency control on the Owon SDS scopes is quite good, even considering the cost, so that makes me suspect my video source.
The second question is about baseline noise. There is discussion on the web about noise spikes being found on the ground connection for the square wave ‘compensation’ signal on the front panel. This may be leakage from the SMPS, but I have not confirmed this. At any rate, this does not affect one’s measurements, even at maximum sensitivity.
By paying attention to proper cable routing, the use of high-quality cables and connectors, good grounding techniques, etc. much, if not all, of the ambient noise can be sufficiently reduced to acceptable levels. I’ve also attached a few photos and screen captures of an SDS7102V scope to show you what can be done at millivolt levels.
The “Baseline noise – normal” is what you will se if the inputs are left open. The -50dBm pictures are using good-quality cabling and correct impedance-matching (the -40dBm and -50dBm are the same setup, just different settings). The -40dBm photo shows a 5mVp-p signal.
**** End reply from dealer ****
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Hey guys, i got my 6062 and wanted to check for the noise issue, but being a newb, cant work out how to get it on the screen! I put the volts per div on 100 or 50 mv's and time on 50us. THe depth is on 10m. But when i scroll upward the oscilloscope will stop at - or + 10 div's, which obviously will not show the top (noise) part of the square waveform.
The probe is on 10x, i can see the waveform at 200mv but i cant see it at 100mv or 50mv. Is this because the oscilloscope is 60mhz / 500m/s?
Is there a setting or something i have to change to increase the amount of div's i can scroll upward? Apologies if this is a really basic question, last time i used an oscilloscope i was 16yo :)
Cheers,
Paul
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Hey guys, i got my 6062 and wanted to check for the noise issue, but being a newb, cant work out how to get it on the screen! I put the volts per div on 100 or 50 mv's and time on 50us. THe depth is on 10m. But when i scroll upward the oscilloscope will stop at - or + 10 div's, which obviously will not show the top (noise) part of the square waveform.
The probe is on 10x, i can see the waveform at 200mv but i cant see it at 100mv or 50mv. Is this because the oscilloscope is 60mhz / 500m/s?
Is there a setting or something i have to change to increase the amount of div's i can scroll upward? Apologies if this is a really basic question, last time i used an oscilloscope i was 16yo :)
Cheers,
Paul
Hello all,
I am new to this forum and this is my first post. I have been looking at purchasing a Owon SDS7102V scope and ready to order it but then I paused after reading about the "video trigger jitter" and "ground noise problem" in this scope.
I contacted my local dealer (Saelig) with the following question and received the following answer along with waveform captures. It looks to me like the GND noise problem is resolved.
What is your opinion? I am new to DSOs so I am unsure if my conclusion is justified by the screenshots provided by the dealer.
**** Begin reply from dealer ****
The second question is about baseline noise. There is discussion on the web about noise spikes being found on the ground connection for the square wave ‘compensation’ signal on the front panel. This may be leakage from the SMPS, but I have not confirmed this. At any rate, this does not affect one’s measurements, even at maximum sensitivity.
By paying attention to proper cable routing, the use of high-quality cables and connectors, good grounding techniques, etc. much, if not all, of the ambient noise can be sufficiently reduced to acceptable levels. I’ve also attached a few photos and screen captures of an SDS7102V scope to show you what can be done at millivolt levels.
The “Baseline noise – normal” is what you will se if the inputs are left open. The -50dBm pictures are using good-quality cabling and correct impedance-matching (the -40dBm and -50dBm are the same setup, just different settings). The -40dBm photo shows a 5mVp-p signal.
**** End reply from dealer ****
7 seas, I bought my SDS7102 from Saelig last January. At the time I didn't know there was a GND noise issue. However, my scope does exhibit the noise depicted in your video, which is also the same noise extensively described in this forum. From what I've learned, I think GND noise is not a very good name for the problem. As the dealer indicated, with good cabling and good grounding you should be able to view very small signals. This is because the scope's internal signal path is very clean and adds very little to the input signal, so basically, what you see displayed on the screen is the signal you input to the scope via the probe or other input cable without any alteration.
So what is the problem? Some of the circuitry within the scope generates EMI. More EMI than other common electronic equipment usually generates. This EMI doesn't affect the display as long as you make sure that it doesn't reach the scope's input. But this is not always easy to do. For example, if you use the ground wires provided with the probes that come with the scope, which are about 6.5" long, you'll find that they act as a very efficient antenna. So this EMI, which we've been calling GND noise, ends up being input to the scope via the ground wire(s). This makes viewing small signals in the scope's 50mV range difficult, specially if you don't limit the scope's bandwidth to 20MHz.
As I indicated in a previous post, you can reduce this EMI interference by using shorter ground wires for the probes, for example, I try to use 3" ground wires if possible. In fact, you can almost eliminate all of the interference if you use the spring clip provided with the probes for grounding. Of course, this is only possible if the signal source and a suitable ground are next to each other.
Chromesphere, you don't need to display a signal to check for the "GND noise issue". Just connect the CH1 probe and it's 6.5" ground wire to the scope's Probe Comp ground terminal. Set CH1 to 50mV/Div, the sweep to 1mS/Div, and watch the display. Ideally, if there was no EMI being picked up by the ground wire, you would see a very thin line displayed. The thickness of the line basically tells you how much interference is being picked up. With the 6.5" ground wire the line displayed by my scope is between 100 and 150mV. With the 3" ground wire it's between 50 and 75mV. With the ground spring clip it's <20mV.
Also keep in mind that the OWON is not the only possible source of EMI, so if you want to make a more credible test you should turn off fluorescent lights and other electronic equipment in the vicinity.
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Thanks TomC, your procedure that you described was pretty much how i was connecting it, however, once you lower the v/div to less than 200mv, the waveform goes off the screen and you cannot adjust vertical position enough to see the top of the waveform.
I dont think there is an issue though. Even in 200mv / div i can sort of see whats going on and it looks like about 20mv of noise which i think isnt alot? Im in the office at the moment, surrounded by all sorts of electronics (inc fluro lights).
Paul
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Problem in new FW and LAN
I'm really curious if anybody else has this problem or if it's just me.
I get answer from Owon about new LAN problem.
They have regognized problem and repair is coming soon. (Estimate: inside 2 weeks.)
About "noisy GND". It is discussed also here http://owon.forumup.com/ (http://owon.forumup.com/)
"noisy GND" is not very good name for this issue. But in time when find this problem it was something like "work name" for this.
This "noise" is EMI noise what is produced inside oscilloscope with several SMPS circuit.
It is mainly as common mode noise. It may pollute signal externally (example via GND wire impedance).
Owon signal pathway inside oscilloscope is very clean. Front end noise level is very low. (also in these "noise issue" units) Clean signal to input BNC and it is clean also on display.
Owon have also worked with this EMI issue. And example units what I get from factory to my stock after half of March there is not this bad high level noise anymore.
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Thanks TomC, your procedure that you described was pretty much how i was connecting it, however, once you lower the v/div to less than 200mv, the waveform goes off the screen and you cannot adjust vertical position enough to see the top of the waveform.
I dont think there is an issue though. Even in 200mv / div i can sort of see whats going on and it looks like about 20mv of noise which i think isnt alot? Im in the office at the moment, surrounded by all sorts of electronics (inc fluro lights).
Paul
If you got the ground and the probe both connected to the ground lug (bottom lug), there is no waveform, it should be a straight line in the center of the screen.
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Attenuation on 1x, probe on 1x, coupling ac, the probe connected to the ground terminal on probe comp and ground clip connected to nothing, i get about 12mv of noise approximately. I dont think this is the right way to do it though, because the ground clip is probably acting like an antenna. With both connected to ground its about half so 6mv. with the probe connected to 1khz +5v's and the ground clip on ground, its difficult to measure the noise in the square wave as the top of the square wave isnt flat (its curved) but i would estimate about 24mv of noise at any given point of the curve.
So if your thinking of getting an owon 6062, you can take my noob advise for what it is, but i would say that, well, atleast MY 6062 doesnt have the noise issue. The 7102 users were saying noise in the order of 100-200mv's! So far there has been no case that i can replicate that sort of noise, unless im doing something seriously wrong.
Paul
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Attenuation on 1x, probe on 1x, coupling ac, the probe connected to the ground terminal on probe comp and ground clip connected to nothing, i get about 12mv of noise approximately. I dont think this is the right way to do it though, because the ground clip is probably acting like an antenna. With both connected to ground its about half so 6mv. with the probe connected to 1khz +5v's and the ground clip on ground, its difficult to measure the noise in the square wave as the top of the square wave isnt flat (its curved) but i would estimate about 24mv of noise at any given point of the curve.
So if your thinking of getting an owon 6062, you can take my noob advise for what it is, but i would say that, well, atleast MY 6062 doesnt have the noise issue. The 7102 users were saying noise in the order of 100-200mv's! So far there has been no case that i can replicate that sort of noise, unless im doing something seriously wrong.
Paul
You may want to try with the probe set to x10 and CH1 set to 50mV/Div. With the probe set to x1 the bandwidth is limited to 6MHz, so you won't see the high frequency noise. Also, don't use the 20mV/Div range because it also limits the bandwidth, to 20MHz in this case. So the 50mV/Div range is the lowest range where you can use the scope's full bandwidth. You should also make sure that the Acquire Length is set to the maximum available on your scope to insure that high frequencies are not ignored due to the sampling rate.
The GND noise that's been reported on the SDS7102's is precisely the noise that is picked up by the 6.5" ground wire acting as an antenna. True this noise can come from sources other than the OWON, but careful experiments by rf-loop and others have shown that some internal circuits in the OWON produce a significant amount of EMI that is picked up by the 6.5" ground wire in the absence of other EMI sources. There have been no issue with the scope's signal path. That's why calling the problem GND noise is somewhat confusing.
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Owon analog front end from BNC to ADC is very clean!
Somewhere 2012 (not remember exactly) they made 1 major change in whole analog front end and it reduce also noise there (somewhere I have these tests). Also earlier version was quite good but littlebit too much random noise. Most old version have more noise but also it was not at all bad.
This (EMI) noise now (more than before) is coming from Owon and in different cases it may connect externally to signal.
Part of noise is radiated and part of noise is conductive.
Noise frequecy band is least over 200MHz. Noise is "peaks" but these peaks include high frequencies. It can easy look what peak is coming from what SMPS circuit if use ecternal oscilloscope or Owon itself. It need take this noise to other input and then pick-up single SMPS circuit signal to other channel only for trig. (just capasitive connection near SMPS circuit. After trig sync it can easy regognize what peak is coming from what SMPS.) Also there is some low amount of TFT databus noise. (oh well, look Rigol youtube where dave put cable near TFT or touch TFT (in this thing Owon is not alone I think)
These noises signals travel in scope ground (whole internal base plate. (Z-plate as owon call it)) and this is source for noise if it can connect to signal.
This RF signal travel through GND wire. GND wire is roughly around 0.2uH inductor. This signal produce voltage over this inductor. Example wirh 100MHz its reactance is totally different as with DC where it nearly zero ohm.
It is just same if common mode noise source is external and if it is example in Device Under Test (DUT) ground. Only noise "current" flow direction is different but same effect.
This is also good to read:
http://cp.literature.agilent.com/litweb/pdf/5989-7894EN.pdf (http://cp.literature.agilent.com/litweb/pdf/5989-7894EN.pdf)
Specially hints 6, 7 and 8 in this case.
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I have the sds7102. I bought it from saelig and it came with the VGA port and software version 2.8.2. I think that firmware updates are available here: http://www.owon.com.hk/down-en.asp?bigclassname=software_upgrading (http://www.owon.com.hk/down-en.asp?bigclassname=software_upgrading). The most recent update seems to be 2013-04-03 which is very recent. After that update my scope is running 2.8.3.
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It's interesting that the links to new firmware are actually pointing to the SDS_Upgrade3.2 package from 2013-03-29.
Also I'd like to use this opportunity to whine a little bit: My scope would sometimes hang after power on. In the end, the main board was replaced. The original board from batch SDS71021211xxx, which could run the newest firmware, was replaced with a board from batch SDS71021209xxx for which newest firmware is 2.8.1.6, the result of which is that I don't have access to new math functions although the scope I bought should have access to them. Also based on trigger out, the waveform update rate went down from 30ish to less than 20 Hz. Bummer :--.
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I've had my 6062 for about a week now and its good, but its buggy...I can make mine hang by entering normal trigger mode and then cycling (not selecting) through trigger mode type (edge video slope pulse). Does it every time. I'm on 3.1.1 though and I have checked my serial and it looks like I CAN upgrade my scope (yay!).
Heres another thing I noticed the other day. I was trying to check my version number, went into utility menu. The H menu (bottom of the screen) appears with only the LAN option. All the other options had disappeared. restarted the scope, same thing. I recalled seeing the options in the usb / pc interface, hooked it up, wasn't there either, only lan options. Unplugged the usb cable, bang, utility menu is back again....thank god I could get the menu back. Some pretty essential options in there!
Also the scope I received came with the LAN option and not the VGA option that was advertised. It also didn't come with the owon bag that was promised. This ebay user is getting negative feedback if they don't respond soon and I will post their name on this forum to avoid. They have a couple more days.
I like the scope, but yeah, its a bit rough around the edges!
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i'm new here and i'm already loving this forum
so i just ordered the owon sds7102v and i saw not many people have information on the 7102v, all i see is on the 7102 (no "v")
when it will arrive, if you guys want to see if owon fixed in this revision some of the problems, just tell me what to test for and i will capture it so you can see what has changed in this one, also it will help eliminate what problems solved and what still needs to be solved.
please detail for me step by step what to test and how to test so i wont mess up the mesurements since this is my first oscilloscope.
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There's no functional difference between the V and non-V version, except that V has VGA out. Everything else should be the same. Still, if you think that you can do a good review of a new edition of 7102, feel free to do so. To what kind of equipment do you have access? Also if you haven't already, do read the review on the first page.
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There's no functional difference between the V and non-V version, except that V has VGA out. Everything else should be the same. Still, if you think that you can do a good review of a new edition of 7102, feel free to do so. To what kind of equipment do you have access? Also if you haven't already, do read the review on the first page.
will do, just thought it's some sort of rev2 for the oscilloscope
i really hope i didn't do any mistake by buying this scope since it was the best in it's price that was really up to date and not like the rigol competitor with the small shitty screen, it felt to me that in these days to buy a scope with this of a small screen is like buying 1950's car
i mean come onn
well i can't specify what i have since it is too much but basically exept a function generator and hot air soldering gun i think i have all that the important stuff
i have an order with 555 chips coming, it should arrive about the same time as the scope so i guess the best thing is to set small 555 circuit and this way others with the 7102 scope can compare with the same schematic i used and i'll give as much reference so we can eliminate power supply noise and such hope it is good enough idea for comparing between the scopes
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Actually the reason why I recommended you to do the review is because your scope is going to be several revisions newer than the one reviewed few years ago. It's just that revision numbers aren't explicit for Owon. Instead you get them from serial number. Last 3 digits are unit number and the rest are some sort of batch number. Each revision seems to be couple of batches "long" and each usually has a little bit different capabilities and potentially different firmware support.
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Actually the reason why I recommended you to do the review is because your scope is going to be several revisions newer than the one reviewed few years ago. It's just that revision numbers aren't explicit for Owon. Instead you get them from serial number. Last 3 digits are unit number and the rest are some sort of batch number. Each revision seems to be couple of batches "long" and each usually has a little bit different capabilities and potentially different firmware support.
i bought the scope in 406$, do you think i've got a good deal, and do you think i did a mistake by choosing this scope in this market?
thank you
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Don't look at me for that kind of advice. The main reason why I got Owon was because it's the only one in it's price range I could find locally that's not crap.
Also I can't say if you made a mistake, since I haven't been able to investigate in detail purchasing options available to you and at the same time I don't know what you actually need. The price looks OK to me, but on the other hand I'm not really up to date with scope rices in general.
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WAITING EAGERLY
Ok, its been 1 month since Chinese New Year ... Anyone have any info on progress? Any "from-the-floor" factory updates from Owon or "new revision / model" designation coming up? I want to get one! IWon Won! (I want One) :>
A question to the Jedis, :> If my main purpose is #1. To learn electronics and #2. To use it to probe and poke around Arduinos (is that what people do with one? ) and #3. Possibly repair/fix "this" and "that" in the house, is there any show stoppers that would hamper me in #1,#2, or #3 in the current production models?
Thanks in advance!
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Do you think it would be worthwhile putting something on the screen to protect it? I still have the original plastic on the screen, but its got air bubbles in it and its a bit distracting. Where could you get something that would fit the screen?
Paul
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That would mostly depend on how careful you are with the screen. In my experience, the screen is tough and has some sort of coating that masks scratches. I really have to bring out a flashlight and a magnifying glass to be able to find any and I'm really good at noticing small details such as screen scratches.
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Cool AndrejaKo, makes sense to me, thanks!
Edit: ah ha! I took the protective plastic off last night and noticed this morning there is a, sort of shiny line across the top of the screen, basically looks like a there already is a screen protector on it that's not perfectly straight! So the layer you pull off when you get it, is kind of like the backing layer you pull off of a mobile phone screen protector. So yeah...it comes with a protector.
Paul
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hey guys, i got my scope finally :-+ took only about 3 - 4 days in dhl
great seller
i did the deal outside ebay and got this price of about 405$
-- whoever wants to look for him, his name is smtzone on ebay --
he included a free bnc leads, and i got with the scope an original bag (lifesaver to store the scope since i don't have space on my desk at the moment and until i will clean a bit to have space, it's nice that it's not getting dust on the meanwhile) which is great, i'll show in the pics\video i will do when youll just tell me if do you want me to do and how
as i suggested, i think i'm going to use lm386m-1 as an oscillator or some similar circuit to have a base line and not use the build in square wave that the comes with the scope
do you have a suggestions for testing this puppy in a way that will show if the problems that were in the 7102 fixed in this revision and latest firmware? if so, please post them out here with details
thank you
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Does the Owon still have noise issues?
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Does the Owon still have noise issues?
I think the reason no one's answered you is that no one really knows. The only person who might (rf-loop) has been strangely silent about Owon lately.
I own an older version of this scope (same generation as marmad reviewed) and I like it quite a bit. I agree with just about everything he said in the review but some of the things that were deal-breakers for him, like screen refresh speed and basic PC software, didn't matter to me. This is a very good scope for the money and the display is a knockout. I hope they get the noise fixed and quit messing around with it. Good luck with your search.
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... I like it quite a bit. I agree with just about everything he said in the review but some of the things that were deal-breakers for him, like
screen refresh speed and basic PC software, didn't matter to me. This is a very good scope for the money and the display is a knockout
Agreed ! Plus the battery option is invaluable if you need it (You do have to fit a Battery on/off switch though, but it's easy).
Even though I've used LeCroys most my life, the several times I had to use the Owon, it has done the job I needed it for. If you get too
carried away with nit-picking every limitation of every scope, you'll never be happy. IF it truly was a piece of cr@p, you'd hear about it from
a LOT more people, in a LOT more forums.
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hi guys, how can i test if i have the noise problem your talking about, can explain to me how to test it and having accurate results
thank you
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Does the Owon still have noise issues?
I think the reason no one's answered you is that no one really knows. The only person who might (rf-loop) has been strangely silent about Owon lately.
I own an older version of this scope (same generation as marmad reviewed) and I like it quite a bit. I agree with just about everything he said in the review but some of the things that were deal-breakers for him, like screen refresh speed and basic PC software, didn't matter to me. This is a very good scope for the money and the display is a knockout. I hope they get the noise fixed and quit messing around with it. Good luck with your search.
Why I'm quiet?
Becouse I do not know.
Sidenote: Also I have been quite busy with some other urgent works and if not enough then also this new Siglent SDG1020 CH1 other issue and CH2 other isue (in some units) but perhaps more rare issue have been "hands full of work". (CH1 square wave jitter/glitch issue have solved by Siglent but CH2 load and amplitude dependent parasitic oscillation in some units in some situations have been hard detective work and still it is partially uncnown. It looks like it is somehow related to changed highest voltage band output amplifier in CH2 output stage. This Ti OPA965 looks more critical for components and PCB parasitics than some other nearly similar amplifier what they also have used.
If I tell they (Owon) have solved it and it is agen just as it have been before it is true but it is true only in these scopes what I have get directly from Owon. I get new lot middle of last month.
It was just time they make changes to HW and I do not know what time they have add these changes to mass production in factory. Now if I tell it is solved and then someone buy from some seller. Then he may be disappointed and his finger show me: you have told lie.
I know only these units what I have in my hand.
I do not know who seller now have ok units and who have issue units and who may even have units before this issue.
Also I can not understand who really make this mistake in Owon. Why make lot of changes to product what is ok in this meaning. These changes are so stupid that even entry level young hobbyist can not do so stupid things. I have waited that Owon tell apologies and tell that sorry "our EE who make these changes did not have anough experience and knowledge for this kind of changes" just as in history Hantek tell after one quite bad situation. (solved long time ago and today it is not anymore in class "pssst... keep your mouth " Just fun history.) I hope Owon do same: I hope that they may well have to admit that errors occurred due to a lack of experience and competence. Perhaps the changes in an underestimation of the complexity. And it is not the first company, which underestimate the SMPS circuits degrees of difficulty.
Now they know.
I hope they give full support for customers who suffer this issue. I hope also they inform distributors how to handle this case so that in end there is satisfied end users.
Also it is still good to remember that (even in these units what have this issue what have talked before) there is not noise issue in oscilloscope froint end. If there is clean signal in scope input BNC then Owon is really clean and perhaps one of best in this oscilloscope class.
There is also published test pictures where can see this issue and what it is after it have modified.
Long time ago I have send recommendations to Owon how they need change/modify circuits and then also recommendations for change some critical layouts on PCB.
What I know is that last time these units what I get from Owon this problem was gone and it looks agen like before this issue birth.
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Does the Owon still have noise issues?
What I know is that last time these units what I get from Owon this problem was gone and it looks agen like before this issue birth.
On April 4 I left the following message at Owon's support:
"I bought my SDS71021246320 from Saelig here in the USA on January 17, 2013. Although I'm generally happy with the performance of my unit, this is one of the units that has the "GND noise issue". This is the issue extensively discussed in the EEVblog and ForumUp forums on the internet that involves excessive EMI radiation from the oscilloscope primarily originating from the SMPS circuits. In most applications this is not very bothersome. However, when full bandwidth is required while proving small signals (less than .5V), obtaining a good reading is very difficult unless the application allows use of the spring ground clip instead of the 6.5" ground lead. To alleviate the problem I have been using a 3" ground lead when possible. It is my understanding, that Owon has resolved this problem since around mid March, and is now shipping units that no longer have this problem. While this is great news for new customers, I would like to know what kind of help is or will be in place to fix units like my own."
I have left messages at Owon's support before and got a quick response. However, to this date, Owon hasn't responded to the above note.
I sent and almost identical e-mail to my dealer and got the following response the same day:
"Thank you for your recent purchase of the SDS7102V scope. At this time, I do not have any information regarding a resolution of this noise issue, either with new products or concerning a remedy for existing scopes. However, I will take up the matter with my contact at the Owon factory, and will respond to your question as quickly as I can. I thank you in advance for your patience."
I haven't heard anything else from my dealer since then. Apparently his Owon contact hasn't responded, or as I fear, is ignoring him the same way I'm starting to suspect Owon is ignoring me and the many other customers that are being inconvenienced by this noise problem.
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hi guys, how can i test if i have the noise problem your talking about, can explain to me how to test it and having accurate results
thank you
I don't know how familiar you are with your new scope so I'm going to give you extremely detailed instructions:
1) Take all probes and LAN or USB cables off of the scope and do a self calibration (Utility, Adjust, Self Calibration). Wait until it's done before doing anything else.
2) Preferably the scope should be away from other noise sources such as fluorescent lights, computers, switching power supplies, etc.
3) Connect a probe to the CH1 BNC and make sure it is properly compensated (see page 13 of the manual). Make sure the probe switch is set to x10.
4) Connect both the probe and the 6.5" ground wire to the ground lug of the Probe Comp terminals.
5) Set up the scope as follows:
CH1:
Coupling = AC
Inverted = Off
Probe: Attenu = X10, MeasCurr = No
Limit = Full Band
Volts/Div = 50.0mV
Vert Pos = 0.00div
Horizontal:
Horiz = Main
Horiz Pos = 0.00ns
Sec/Div = 500µs
Trigger:
Type = Single
TrigMode= Edge
Source = CH1
Coupling = AC
Slope = /
Mode&Hold = Auto, Holdoff = 100ns
Level = 0.00mV
Acquire:
Mode = Peak Detect, or, Average
Length = 10M
6) The following is what I get on my scope, which has the noise problem, If you get a much thinner line you probably don't have the noise problem. You may want to post the images from your scope for others to see.
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hi guys, how can i test if i have the noise problem your talking about, can explain to me how to test it and having accurate results
thank you
I don't know how familiar you are with your new scope so I'm going to give you extremely detailed instructions:
1) Take all probes and LAN or USB cables off of the scope and do a self calibration (Utility, Adjust, Self Calibration). Wait until it's done before doing anything else.
2) Preferably the scope should be away from other noise sources such as fluorescent lights, computers, switching power supplies, etc.
3) Connect a probe to the CH1 BNC and make sure it is properly compensated (see page 13 of the manual). Make sure the probe switch is set to x10.
4) Connect both the probe and the 6.5" ground wire to the ground lug of the Probe Comp terminals.
5) Set up the scope as follows:
CH1:
Coupling = AC
Inverted = Off
Probe: Attenu = X10, MeasCurr = No
Limit = Full Band
Volts/Div = 50.0mV
Vert Pos = 0.00div
Horizontal:
Horiz = Main
Horiz Pos = 0.00ns
Sec/Div = 500µs
Trigger:
Type = Single
TrigMode= Edge
Source = CH1
Coupling = AC
Slope = /
Mode&Hold = Auto, Holdoff = 100ns
Level = 0.00mV
Acquire:
Mode = Peak Detect, or, Average
Length = 10M
6) The following is what I get on my scope, which has the noise problem, If you get a much thinner line you probably don't have the noise problem. You may want to post the images from your scope for others to see.
Thank you very much, your explanation was accurate and very easy to understand :-+ even that i am very new to this scope (or any scope at all :scared:)
my scope have the noise problem also, mine get about 86mv in Vp and 29.6mv in Vk, but what i saw is that my scope is on about 2Mhz on the right lower corner and yours shows 470
as i understand it is because you used X1 and i used X10
also, i would love to know about how to test other problems like this if you can post a step by step like you did with the noise issue :-+
thank's again
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Hello.
I have a SDS8102V and, today I made the "test of noise" using the description of "TomC".
With a 200MHz probe (P6200) I get:
-Peak: Vp=24mV, Vk=9.2mV
-Average: Vp = 14mV, Vk = 7.8mV
With a 100MHz probe (T5100):
-Peak: Vp=19mV, Vk=8.5mV
-Average: Vp=12mV, Vk=6.5mV
I suppose that I don´t have the noise problem. What do you think?
Without probes I have measured a level noise of ~1 mV (BW = 20MHz) [x1] and ~2 mV (Full Band) [x1] with or without 50 ohm load.
I hope that these data be useful. ;)
Best regards.
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You guys have nothing to worry about!
using the same instructions by TomC, my 50mV/div setting is full of noise, and the 100mV/div setting shows that it's about 800mV p-p
sds71021219xx
firmware: 2.7.0
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Oh, and once I wanted to buy this Owon scope... Anyway, is this problem even at the 200MHz version SDS8202??
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You guys have nothing to worry about!
using the same instructions by TomC, my 50mV/div setting is full of noise, and the 100mV/div setting shows that it's about 800mV p-p
Wow! Ladies and Gentlemen, I think we have a winner!
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You guys have nothing to worry about!
using the same instructions by TomC, my 50mV/div setting is full of noise, and the 100mV/div setting shows that it's about 800mV p-p
Wow! Ladies and Gentlemen, I think we have a winner!
lol :-DD :-DD
can someone prepare some step by step ultimate guide to fix the noise all by our own (owon :-- haha)
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As a point of reference, here are some shots of the noise on an SDS7102 with a build date of 2011, 27th week (old hardware and well before the noise issue surfaced). Probe at x1, with the long ground, is attached to the scope's ground point in the first three shots.
Shot #1 Shows noise level of 4.8 mV P-P. Note: 2mV per division automatically limits the bandwidth to 20MHz.
Shot #2 Shows noise level of 11mV P-P at the 5mV per division setting and full bandwidth.
Shot #3 Shows noise level of 4.4mV P-P at the 5mV per division, but with the bandwidth again limited to 20 MHz.
Shot #4 Shows the noise level with the probe held about a foot (30cm) in front of the scope. This measurement was taken with the scope in full bandwidth mode.
TomC's noise, while nearly twice mine, is probably not considered a problem. Electroguy definitely has an issue. It would be interesting to know the build dates of those units, and to get a few more points of reference.
The sharp-eyed among you will notice that my scope is actually a Aktakom. This is just a rebranded OWEN SDS7102. My serial number even reads: SDS71021127xxx
rf-loop's fix for the new models actually appears to reduce the noise to a point slightly below my version. Let's hope OWON implements his fix and then leaves the damn thing alone!
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It is better to save the images in png format.
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It is better to save the images in png format.
Yes, I noticed that myself. I've updated the post accordingly.
Thanks.
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Oh, and once I wanted to buy this Owon scope... Anyway, is this problem even at the 200MHz version SDS8202??
This whole terrible issue is in some manufacture lots.
Owon make some modification for main PSU (there is 2 SMPS) and adapter board what have also SMPS circuits.
Some schoolboy "EE" propbably do this work becouse of course this kind of small changes are easy.. only move some components and small changes in layout and then some components away what looks like do nothing... ... oh yes.. simple woirk and then becouse it is so simple directly order new PCB's for factory product line.
Yes, if look with signal generator etc.. all looks ok. So, go on...
But in test lab... they do not as usually some peoples do... connect probe GND to somewhere and center to somewhere.. professional peoples have mesurement practices and probe with GND longwire is only for some "blinking led" measurments.
Also I do not this if can avoid. Only for slow high level signals and so on in some service situation where only fast need look like "are there anybody home". And no problem with this common mode noise.
Also there was no any reason to measure GND. Why I measure and watch just GND with oscilloscope. Is it fun, or just becouse bored and nothing better to do..
But then, some really may use oscilloscope probe with long GND wire for low level signals or fast signals.
If there is noise, first thing is take this short GND spring.
Oh well... then connect probe longwire inductor as GND to scope GND together with probe tip... and voila...screenfull of noise... what hell is going on - nearly drop from my seat.
After then start investigations that what hell is going on and why...screen is full of noise.
If connect clean signal to input BNC all is ok and more than ok... it is very good ok, also if use normally used short GND there is no problem at all.
There is common mode high frequancy noise what is just converted to differential mode with this probing.
Now we know. Now also Owon know.
Later after I have time I will show some test pictures what ahave made using with one original "noisy GND" issue oscilloscope from factory and then just with exactly same tests using factory new unit after this issue is repaired by Owon.
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Hello All,
My first Post.
I wanted to buy a O'scope soon and the Parallax Forum.com pointed me to this Site for Test Equipment feed back. I had read in the Nuts & Volts magazine about the SDS5032E Scope. They mentioned the SDS7102. That was about 2 mths ago. I've read most of the reviews about it and its noise problems. I did email Owon and got a quick response about them working the problem and how to avoid it about a month ago. I'm still waiting to see something on this forum about the problem being 99 - 100% fixed before I buy. This Scope is in my price range that I want to spend. I'm working with Parallax.com Micro-controller (BS2 MC & my own OEM's). Some day soon I may move up to the Spin MC from Parallax, but not much more for now so this Scope should be more then enough. But, I don't want to buy....I will NOT buy...a known problem. I just read the latest feedback and will be waiting for more. If the fix's works, how can I be assured that I get the latest/newest units off the assembly line.
I'll be holding on to my dollars til I read here that its fixed.
Thanks to all who have given feedback(s) about the problems.
waiting......... :-BROKE
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TomC's noise, while nearly twice mine, is probably not considered a problem. Electroguy definitely has an issue. It would be interesting to know the build dates of those units, and to get a few more points of reference.
sds71021219xx
2012 week 19
firmware: 2.7.0
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Maybe this has been answered before but how badly does this affect normal signals you are checking on the scope?
Does it make small 100-200mVpp signals unreadable, or just butt ugly?
Is it noticeable with say 3.3V logic?
There is no perfect scope, I just want to know how crappy it is, to tell if it will interfere with what I may be doing.
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I would not buy any Owon today, but if yes, try the scope at the shop, if it is OK. Do not buy over internet. It seems that Rigol DS1000, Siglent or Hantek hardly ever have such problems with noise.
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About Reading MAINS
my scope arrived with 2 pin mains cable, does it mean that with this cable i can test mains? if not, how can i test mains without having any risk and without using fancy equipment like special probes?
thank's
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Always be careful. Your scope should be grounded when powered by AC 230V or 110V. Replace your power cord. And there is other rule. When working with high voltage use only your one hand, so the risk of electric shock is reduced.
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... how badly does this affect normal signals you are checking on the scope?
This is really good question!
Does it make small 100-200mVpp signals unreadable, or just butt ugly?
No and yes. It depends how user use probes or how user connect signal to the oscilloscope input.
And it depends what you are doing.
This claim I can repeat agen becouse this can be some kind of starting point for thinking:
There is oscilloscope input BNC connector. From this point to inside and finally visible waveform on the screen there is no problem. In this oscolloscope class this is cleanest what I have seen. Even if oscilloscope individual is this "GND noise issue" unit or usual "normal" unit. I can compare also these.
Analog front end and ADC is good, and extremely good in this class. If someone have better, welcome with it to my workshop and let's make test for compare in real world with equal tests.
But then there is this dirty side:
First, if you do something very sensitive and you need turn off all swithc mode lights and computer and phone and energy saving lights and if HF/VHF/UHF radio/TV stations RF fields do problems it is best you forget this Owon and specially unit what have this extra "noisy GND" issue. Becouse it radiate RF from its several SMPS circuits and then other things like TFT is also radiating EM noise but this is not Owon alone.
If you need "EM black room" you need absolutely forget this Owon (good and bad individuals, all) and also nearly all other oscilloscopes exept some very special equipments. I have example one RF generator what can take to "black room" (HP8642B with low EMI options. It is so heavy there read it need two person for carry)
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Owon made some changes to main power unit and adaptr board.
After these changes this noise level rise.
This total noise include spread spectrum and from these noise sources inside scope it travel by radiating and conducting and outside of scope it can say it is "common mode" noise. Somewhere near circuits it is differential mode also - of course.
It radiate and it may this way pollute your signal or it can travel also using your probe cable and pollute signal. Common mode noise things are very complex and it is not easy understand how they affect. There is so many things and also now this is really spread spectrum noise. Some frequency components do other things and some other, they are like group of different animals.
It looks fynny, if you move your probe cable, if you touch it with hand, if you move your device under test... all may do some change what you see.
Now there is several things what can do for reduce this problem. I do not explain here now these exept...small amount. But it need somehow understand it. You can not see anything about this noise as long as it stay common mode. If you see it, you have somehow changed it to differential mode or piced up it as differential mode.
First test you can really see how it works and then think "why":
Take your probe and connect it 10x and oscilloscope 50mV/div(scope setting 10x for probe but it do not mean anything if you forget it 1x... then just 5mV but change it in your mind)
Connect probe GND wire to Probe comp 1kHz output GND. Connect probe center tip to same point.
Turn oscilloscope for quite slow horizontal speed but highest possible samplerate (using max memory) OR turn acquire mode to "Peak".
(in peak mode it use always full samplerate for find highest and lowest sample in one sample "group" (explanation, if displayed samplerate is 1Msa/s and there is 1GSa/s samplerate it means it drop out 999 and keep one. In my text this "group" meant this 1000 sample. But peak mode look these samples for find "min-max" )
Then do same but open your probe pouch and find small metal spring. Take probe tip hook away. Insert this spring over tip GND area near center tip. So that all spring turns are over this (for avoid extra inductance). Now, connect your probe GND and center tip agen to probe comp. out GND. Where is noise? Why?
Ok lets make other test (and remember, probe comp out is NOT clean, it is only made for adjust probe compensation and there HF noise is not problem.
Connect probe tip to probe comp. signal and GND spring spike to probe comp GND.
Do not connect probe black GND wire. First look 1Vpp and then turn (scope input DC) even to 100mVdiv or 50mVdiv. Look signal bottom. Adjust trig and vertical shift if need. Noisy? Very very noisy?
Then, take GND spring away and just same using probe black GND wire. Noisy? More than just before?
Why there is so big difference and only with this quite small difference in probing method?
It is good to understand least some amount.
(these are also important things for probe use with high frequancies/fast risetimes signals, always, not only this case, even with best possible oscilloscopes.)
I have made tests using one "noisy GND" individual factory original unit and units what I have last get directly from factory.
Just due to lack of enough free working hours these all results images are just raw "in the basket all together" and then lab hand write paper notebook explanations. It need work before they are ready for publish. And then, if I show these. I'm biased seller - so.... I do not know if I do it here or not. (90% of my customers are local and they can come visit and see with they own eyes if they want)
So, answer for this
Does it make small 100-200mVpp signals unreadable, or just butt ugly?
No and yes, depends how you do and what are you doing.
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Always be careful. Your scope should be grounded when powered by AC 230V or 110V. Replace your power cord. And there is other rule. When working with high voltage use only your one hand, so the risk of electric shock is reduced.
thank's
i will replace my cable (too bad this is the cable arrived from factory with the scope), why is it important to ground the scope? also, so can i test mains without any special equipment? i would love to get more details
thank you
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Thanks for the info rf-loop.
Could I impose on you to take 4 more screens. First using the same settings on the previous page of this discussion, but connect so you can see the 5v 1Khz signal instead of going to ground and zoom in on the top and bottom portions of the signal using AC and then switch to DC coupling. I would like to see how much noise is present on the portions of the square wave that should be relatively flat.
This will give me some idea of how bad it will be. I am most likely going to get an SDS7201V since it seems to have the features I am looking for. From what I understand at the worst I could mod it to fix the ground noise issue. For the price its tough to be picky.
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Not what was asked but these are from allready made tests.
This time I do not have time for extra tests and document these etc.
I hope pictures are self explanating. (use file name and text and information in pictures.
NoiseBad oscilloscope is SDS7102V original from factory and time ago when this issue come on table.
NoiseNormal: Oscilloscope is SDS7102V original from factory after they have worked for this noise issue. (these scopes arrive from factory 15.03.2013 to me)
In test you can also see how big difference is with probe "long wire" GND or with short GND spring.
(it is becouse this long GND wire have "big" inductance - something between 150-200nH and not only in GND wire, also inductance between this point where it is connected to this point where probe tip is connected. You can see "noise issue" oscilloscope results with better GND practice)
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nice post rf-loop, very informative, thank you
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rf-loop, I wish i could get mine to look as good as your 2n picture, let alone your 2a!
This is mine, and owon said that this is normal :(
do you think your mod that you mentioned earlier to the SMPS would fix this?
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rf-loop, I wish i could get mine to look as good as your 2n picture, let alone your 2a!
This is mine, and owon said that this is normal :(
do you think your mod that you mentioned earlier to the SMPS would fix this?
Please do some more tests.
1. Do exatly same as your picture is exept: run with battery power. (sidepanel switch off or AC power cable disconnected)
2. Agen exatly same but take whole battery out from oscilloscope and AC power connected.
3. Do exactly same test as yesterday 11:31:56 PM message but connect probe using GND spring. (battery assembled and with AC power and battery charging)
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1. Do exatly same as your picture is exept: run with battery power. (sidepanel switch off or AC power cable disconnected)
The picture in my previous post was with battery only.
2. Agen exatly same but take whole battery out from oscilloscope and AC power connected.
Wow, it works better without the battery!!!
See 2 pictures attached with no battery (one with ground spring the other with long clip).
3. Do exactly same test as yesterday 11:31:56 PM message but connect probe using GND spring. (battery assembled and with AC power and battery charging)
See 3rd photo.
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Thanks rf-loop.
Electroguy, how old is your SDS? NM found it.
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What do the diagonal lines mean in the attached photo?
Thanks...
Earl
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What do the diagonal lines mean in the attached photo?
Thanks...
Earl
The way I understand it, the diagonal lines are just filler indicating that there are samples in that area that are not being displayed. In peak detect mode the scope always uses the maximum sampling rate, but only the highest and lowest samples are displayed. With the time base set to 500 micro secs, if my math is right, you get about 500,000 samples per division. However the screen only has 800 x 600 pixels (1 division is about 53 x 60 pixels). The beauty about the Owon's deep memory is that although all the samples are not displayed, they are stored in memory. So if you press Stop, you can change the time base to say 10 micro secs, and see many of the samples that were not visible before. As you do this you'll see the area with the diagonal lines shrink because there are fewer samples that are not being displayed.
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Any news about the new PSU and adapter? :-//
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Well, here's my scope (my first scope!) and I'm not too happy, though I don't know enough to understand when this sort of error will creep into measurements and affect me. I received the scope from Saelig about a week ago. I think I'm going to ask to either return it or see if they'll fix it. I really like the scope except for the uncertainty of whether this issue will ever be a problem for me. I'm just a hobbyist and still learning and $400 makes this the most expensive electronics tool I'll own for the foreseeable future. I don't want to spend it on a tool that is clearly flawed, especially in a way that many units of the same type are not.
I took screenshots of the noise both when measuring the 1KHz square wave (which works out to about 50mV of noise in a 5v signal) and the noise when the probe is grounded, which is about 200mV peak to peak.
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Can you please share your serial number of your unit ?
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Well, here's my scope (my first scope!) and I'm not too happy, though I don't know enough to understand when this sort of error will creep into measurements and affect me. I received the scope from Saelig about a week ago. I think I'm going to ask to either return it or see if they'll fix it. I really like the scope except for the uncertainty of whether this issue will ever be a problem for me. I'm just a hobbyist and still learning and $400 makes this the most expensive electronics tool I'll own for the foreseeable future. I don't want to spend it on a tool that is clearly flawed, especially in a way that many units of the same type are not.
I took screenshots of the noise both when measuring the 1KHz square wave (which works out to about 50mV of noise in a 5v signal) and the noise when the probe is grounded, which is about 200mV peak to peak.
Did you do a Self Calibration before taking the screen shots? I've found that this influences the amount of noise I see in my SDS7102. You may also want to try using the spring ground clip instead of the 6.5" ground wire. If the noise that you are seeing is common mode noise from the Owon's SMPS circuits converted to differential noise by the 6.5 ground lead, using the spring ground clip should decrease the noise dramatically. If it doesn't you may have a malfunction in the signal path that needs to be repaired.
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Have you tested the channel 2 ?
On this unofficial document (I attached only the first page) the problem seem appair only on channel 1 and NOT on channel 2 ...
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Oh, it's like everyone should rather buy Rigol than this noisy Owon... :-BROKE
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The noise is the same on channels 1 and 2. My screenshots were made after calibration.
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To "rf-loop" answer this pelase: :-X
a). What noise level is right for OWON?
b). Will send Owon spare parts to all with this problem?
c). What items (s/n) are affected? And do not tell me that OWON do not know.
rf-loop reply:
a)
Noise levels what are here in images I can accept.
here:
https://www.eevblog.com/forum/testgear/sds7102-old-stock-serial-identification-(with-noise-issue)/msg231565/#msg231565 (https://www.eevblog.com/forum/testgear/sds7102-old-stock-serial-identification-(with-noise-issue)/msg231565/#msg231565)
Also here: tested "normal" and "noisy" SDS7102.
https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/msg226398/#msg226398 (https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/msg226398/#msg226398)
This "normal" I can accept. This "noisy", this level I can not accept, but still also in many cases with it can live IF do not need measure very low level signals just with using probe long GND wire. It need also note that this "noisy" scope conducted and radiated RF noise may disturb some sensitive circuits what you are testing.
I can not write rules what noise is accepted and what is limit what can not accept. Also before this need
If someone want define the limit values there ??should first create a definition for it. Who determines what and how to measure.
b) I can not answer this. First people need ask seller. If seller do not want help and or solve this problem then customer need ask Owon. Only Owon make decisions how they handle individual situations.
c) I do not know. Also I have never told that Owon do not know. But, I do not know what Owon know and what not. Who want know he can send fax, call phone or send letter to Owon and ask Then, after get answer from Owon, he know what Owon want tell. Also in this case you do not know what Owon know, you know only what Owon tell to you. If they give some public information it is as it is. If they give some personal answer it is only just it and nothing more.
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This is beginning to resemble the ring.
Nature of the problem is quite well aware of when you read and studied here in the forum what all peoples have tested and discussed over long time in many many threads about noise overall and about this case.
Universal noise level threshold value at which the device should reject or accept you're not going to get anywhere.
I thought so, ie we are going to anywhere. Or even more explicit: Probably OWON will do nothing for you if you have a machine with this problem, under warranty or not. :-DD
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Here some add for this message:
https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/msg226398/#msg226398 (https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/msg226398/#msg226398)
These images are really bad and also in this case whole measurement do not meet any kind of acceptable lab test "good practices".
There Owon probe connected to oscilloscope GND. Also probe GND wire is connected to same GND point. (probe comp gnd)
Probe is 10x for better BW.
Probe is connected to spectrum analyzer 50ohm input. Every people understand that level itself is now "un known". There is high attenuation due to this connection.
Note: in all three images connection is same.
1. Both scopes OFF.
Scope is just as antenna.
2. Probe connected to "normal" Owon and alone it is power ON and running for avoid radiated noise from noisy one.
3. Probe connected exactly same way to noisy Owon and now other is OFF.
Spectrum analyzer adjustments are not optimal, level is undefined but pictures are comparable with each others.
(sorry I did not find time for play with HP-IB for pick-up screen capture from this OLD workhorse HP8568B and also no time for find some camera stand but these images show something about this noise. Note also these commercial broadcasts as example FM stations so they are also in all images and you may find some idea what is level of this Owon GND noise. Nearest FM stations are over 10km distance. There can see also some other RF signals (look 1. image). If there is nothing, it is just flat noise floor.
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rf-loop, can you share images of the new boards? :scared:
Thanks
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rf-loop, can you share images of the new boards? :scared:
Thanks
Of coiurse I can do it as also many other things I can do... but still I do not many things what I can..
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rf-loop, can you share images of the new boards? :scared:
Thanks
Of coiurse I can do it as also many other things I can do... but still I do not many things what I can..
But you know what. The best that you're doing is not worry about all existing customers! :--
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He does not work for OWON.
He may be a supplier of OWON's but it is not his job to troubleshoot or give fixes to OWON, he does it because he wants to.
If he gets time and feels like doing it im sure we will get pictures of the new boards.
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Excuse me if my question probably is stupid:
If with a standard stock owon probe there is this problem, there is on the market a "particular probe" that can reduce this problem without use "a short ground" ?
I' am not an expert but the problem is clear for me but I serching for a solution, if exist, a "short ground" is a big compromise is not a "pratical solution".
Other scope don't need "a short ground" becouse the difference is near zero.
I hope exist an alternative ...
If someone have some alternative , pratical solution , (not other informations about the problem that is clear for me), please share
The short answer to your question, at least in my case, I've seen some improvement with a different passive probe while still using a 6" ground wire. This is possible if the probe's input capacitance is lower than the stock Owon's probe. With the stock Owon probe my SD7102 displays 100mV pp of noise in Average 16 acquire mode. The noise generated by my scope is mostly around 100MHz as I have verified with the FFT display. I checked the input capacitance of my probe and the inductance of my 6.5" ground wire with an LC meter and got 15.2 pF and 141nH. The resonance is then around 109MHz which leads me to believe that the noise I see is exaggerated by the Owon stock probe ground wire combination due to its resonant point.
I then tried a Tek P6061 which I had around which has 9.5 pF input capacitance and uses a 6.2" ground wire which measured 125nH. In this case the resonance is around 146MHz and although the ground wire is almost as long as the Owon's the noise displayed by my scope went down to 75mV pp. Note that the P6061 is rated at 60MHz, however, I checked it against the Owon's stock probe and its response up to 110MHz was nearly identical.
I've also tried using a snap on small ferrite core on the Owon's probe stock ground wire. This also causes the noise displayed by my scope to go down to 75mV pp. I calculated the resonant point for this combination and it came out to be around 39MHz. However, this solution will cause exaggeration if you measure signals in that frequency range or if some other device emits common mode noise in that range. I happen to have a laptop PS which emits noise in that range and when I plugged it in the same outlet I was using for the Owon the noise went of the screen.
The best results I've had so far is using a custom made 3" long ground wire with the Owon stock probe or a stock 4.25" ground wire with the P6061. In both cases the noise displayed by my scope goes down to 45mV pp.
What I've learned from all this is that when working with high frequency signals or fast rising signals, the shorter the ground wire the better accuracy you will obtain. In these cases an effort to use the spring ground clip is well justified for me. A long ground wire is tolerable for low frequency work and slow rising signals, and if the Owon's noise is getting in the way because the signals are small, I either use the 20MHz bandwidth limit or the X1 probe setting (6MHz bandwidth limit) depending on the frequencies I'm interested in. If I'm looking at recurring signals I often use the Acquire average mode to get a cleaner more stable display.
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I have reviewed the mainboard of this oscilloscope, and I found some atrocities. :palm:
The A/D (ADC08D1010 on my oscilloscope) is powered by a TPS4022, entirely. OWON engineers are a little beast! But there is more.
The ADC08D1010 datasheet says (Pag.33): "The Va and Vdr supply pins should be isolated from each other to prevent any digital noise from being coupled into the analog portions of the ADC. A ferrite choke, such as the JW Miller FB20009-3B, is recommended between these supply lines when a common source is used for them"
Q: Where is the ferrite?
A: Very simply, does not exist. Why spend money on this? LOL...
Probably -7.6V at the PSU generated with a MC34063 switching at 100KHz, is used to power a portion of the input stage. And to do this before goes through a 79M05A (RR ~40dB @ 100KHz), ie in all probability the input stage is using +-5V. With this configuration -5V should have a good amount of noise, but surely +5V plane/line have more noise even.
I not know the new changes introduced by OWON, but unless OWON made a miracle I can not believe the results shown in the previous images. This problem has been corrected? Only with a new PSU and DC/DC board?
OWON engineers are as good as their customer service :-DD
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Hello.
I have a SDS8102V and, today I made the "test of noise" using the description of "TomC".
With a 200MHz probe (P6200) I get:
-Peak: Vp=24mV, Vk=9.2mV
-Average: Vp = 14mV, Vk = 7.8mV
With a 100MHz probe (T5100):
-Peak: Vp=19mV, Vk=8.5mV
-Average: Vp=12mV, Vk=6.5mV
I suppose that I don´t have the noise problem. What do you think?
Without probes I have measured a level noise of ~1 mV (BW = 20MHz) [x1] and ~2 mV (Full Band) [x1] with or without 50 ohm load.
I hope that these data be useful. ;)
Best regards.
Default scope.
Run scope half hour. Do selfcal.
Push CH1 to vertical center.
set trigger level somewhere out from signal, example to + or - 20mV (there is autotrig on)
Acquire mode Peak
Memory lenght 1M.
CH1 5mV/div and DC, and BW limit off.
CH1 BNC covered with 50ohm terminator without center pin connection. (no matter if you think no effect or some, just do it)
(CH2 off)
Turn horizontal speed to 1ms/div
Turn Measure on and Pk-Pk CH1
Show copy from screen.
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Hi!
According to your instructions here is the result, with 50ohm terminator on CH1: ;)
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Hi!
According to your instructions here is the result, with 50ohm terminator on CH1: ;)
This result is quite good. It tells that analog front end itself including ADC noise level is ok.
But just small amount more that typically in SDS7102, perhaps due to slower adc 7102 have some less noise but also this kind of difference may be just differencies between individual units.
Of course it can be better if really start do all things for lowest possible noise without changing ADC around of whole front end circuits. But, my opinion is that now there is all ok.
Take some other oscilloscope... Agilent, Tektronix, and stay in 100MHz models and not any "high end" or middle end model... I believe that result is around same or worse.
After sad "CH1" noise issue in time ago Owon front end have been good if look noise level.
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Tell the same to all who have problems with noise. :blah:
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Tell the same to all who have problems with noise.
I have told many many times it. :blah:
Noise problem is NOT in signal pathway inside oscilloscope after BNC input.
But now there just before you try tell that there is ADC on board and power linbes and this and that... your picture show exatly that problem is NOT there.
This noise GND problem is exactly in adapter board and PSU SMPS circuits. And I can proof it without any holes. Other but much lower and also not SO serious noise source is TFT databus. Also This is inspected and proofed.
If I connect clean signal to you scope input, it is clean and it stay clean. If I connect clean signal to nousy GND unit there can see just barely small extra noise in some very selected tests. Also this is inspected and this can test in any lab where is real enough good tools for this.
It is also inspected that what is source for single noise component in whole total noise "chaos".
I have even told how this regognization can do very easy.
It is not question anymore that what is this noise and where from it come. This is fact, not mutual.
So, what is your point with this ADC talking related to this noise problem?
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Tell the same to all who have problems with noise. :blah:
I have to agree with rf-loop on this, the noise I see on my SDS7102 is common mode noise converted to differential noise by the 6.5" ground lead. As evidenced by the test you just did, my scope also has a clean signal path, maybe just a little bit better than yours. Excessive noise in the signal path would be a deal breaker, for example, noise injected via the ADC as you imply. But this is just not the case with the current GND noise situation. I view this problem as an inconvenience not a deal breaker. That said, I would be very happy if Owon decided to bite the bullet and offer to fix or provide upgraded boards to those of us that have to put up with this inconvenience.
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This noise GND problem is exactly in adapter board and PSU SMPS circuits. Yes, and the rest of the design also contributes (bad design). Probably common mode noise is converted to differential noise by the 6.5" ground lead.
One moment I have the solution: using a ground lead of 0.00001". :-DD
Do you think we're idiots?
A message to OWON: "Fool me once, shame on you. Fool me twice, shame on me."
You dont remember the beginning? See Attach.
OWON has improved this oscilloscope at expense of all that have purchased it.
Quote from: TomC
"That said, I would be very happy if Owon decided to bite the bullet and offer to fix or provide upgraded boards to those of us that have to put up with this inconvenience." Totally agree. :-+
Q.C. passed :phew:
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Can you tell us what was year you buy this old version or did you buy second hand, perhaps oldest versio or nearly prototype?
2010 or?
All what is inside have changed many times if compare to this old version what can see in pictures.
What is same today and example last year is TFT panel. There the similarities with this old version.
OWON has improved this oscilloscope at expense of all that have purchased it.
Do you know how much money I have send to Hewlett-Packard they can develop they some mistakes and develop better machines. And same for Mercedes Benz or even Seat.. they have sold crap to me and later they have also, using my and others money, developed some bad things better. This is how this train go forward - I do not want stop it.
But now, you can think what is Mr Henry. I can tell you... it is not new soft drink brand and it is not new candy. But he do some magic tricks if it meet fast changes...fun guy.
No one have told that making Mr Henry more small it solve this primary problem. But it may reduce its effect in measurement. Also it do not mean that with this trick do not need repair primary problem.
|O
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But now, you can think what is Mr Henry. I can tell you... it is not new soft drink brand and it is not new candy. But he do some magic tricks if it meet fast changes...fun guy.
|O
Ch1 is connected to the signal source via a probe test point, Ch2 is connected to the same source using the 6.5" ground lead.
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Hi, everybody.
I think so that the fan of my SDS7102 has gone.
I can't hear it (and I don't remember if it is hearing in past) and the front part of oscilloscope is warming!
How can I see, if the fan is working, without open it?
(Sorry, for my english...)
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Hi, everybody.
I think so that the fan of my SDS7102 has gone.
I can't hear it (and I don't remember if it is hearing in past) and the front part of oscilloscope is warming!
How can I see, if the fan is working, without open it?
(Sorry, for my english...)
Place a piece of tissue over the large vent on the back of the scope, you should see it gently vibrate if the fan is working.
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Thanks for the reply.
There is no any vibration of paper or something light tissue!
It is explained now why this reach over 45°C in front of case!
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(My Agilent DSOX2000 stays cool all the time... :-- )
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I always use the pointy end of a small cable tie .. you can tell what rate it's spinning by the clacking,
just like we used to put on bicycle wheels :-)
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The short answer to your question, at least in my case, I've seen some improvement with a different passive probe while still using a 6" ground wire. This is possible if the probe's input capacitance is lower than the stock Owon's probe. With the stock Owon probe my SD7102 displays 100mV pp of noise in Average 16 acquire mode. The noise generated by my scope is mostly around 100MHz as I have verified with the FFT display. I checked the input capacitance of my probe and the inductance of my 6.5" ground wire with an LC meter and got 15.2 pF and 141nH. The resonance is then around 109MHz which leads me to believe that the noise I see is exaggerated by the Owon stock probe ground wire combination due to its resonant point.
I then tried a Tek P6061 which I had around which has 9.5 pF input capacitance and uses a 6.2" ground wire which measured 125nH. In this case the resonance is around 146MHz and although the ground wire is almost as long as the Owon's the noise displayed by my scope went down to 75mV pp. Note that the P6061 is rated at 60MHz, however, I checked it against the Owon's stock probe and its response up to 110MHz was nearly identical.
I've also tried using a snap on small ferrite core on the Owon's probe stock ground wire. This also causes the noise displayed by my scope to go down to 75mV pp. I calculated the resonant point for this combination and it came out to be around 39MHz. However, this solution will cause exaggeration if you measure signals in that frequency range or if some other device emits common mode noise in that range. I happen to have a laptop PS which emits noise in that range and when I plugged it in the same outlet I was using for the Owon the noise went of the screen.
The best results I've had so far is using a custom made 3" long ground wire with the Owon stock probe or a stock 4.25" ground wire with the P6061. In both cases the noise displayed by my scope goes down to 45mV pp.
What I've learned from all this is that when working with high frequency signals or fast rising signals, the shorter the ground wire the better accuracy you will obtain. In these cases an effort to use the spring ground clip is well justified for me. A long ground wire is tolerable for low frequency work and slow rising signals, and if the Owon's noise is getting in the way because the signals are small, I either use the 20MHz bandwidth limit or the X1 probe setting (6MHz bandwidth limit) depending on the frequencies I'm interested in. If I'm looking at recurring signals I often use the Acquire average mode to get a cleaner more stable display.
What you think about these probes ?
Are better then the standard Owon Probes (and reduce the noise) ?
What are the best of these probes ?
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I have forget the other attach.
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What you think about these probes ?
Are better then the standard Owon Probes (and reduce the noise) ?
What are the best of these probes ?
Probe Master's oscilloscope probes are much better than OWON's or any you'll get with most Chinese scopes. I have an OWON scope and a Probe Master probe, so I've seen both side-by-side and there's no comparison. However, a better probe used with the typical 6" ground lead will NOT reduce noise. If anything it's wider bandwidth might pickup MORE noise. Better construction, less circuit loading, and more options for shortening your grounds (I.E... 3" ground leads, HF ground clips, BNC adapters, etc) are the advantages of a better probe.
Lastly, I can't find a PM2817 probe listed on Probe Master's website so I assume it discontinued or bogus and you're seeing it sold by some third party. If your going to buy a Probe Master probe I'd deal directly with them to be sure of what you're getting.
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I have forget the other attach.
From the specs you posted, it appears that these probes have a lower input capacitance than the Owon's stock probes. Based on my experiments, I would expect them to reduce the amount of common mode noise produced by the Owon's SMPS circuits that gets converted to differential mode noise. This is because the resonant frequency with a similar 6" ground wire will be higher and at least it won't exaggerate as much the Owon's 100MHz noise. But remember, I have only tested this with one scope, mine, which mostly produces noise in the 100MHz range. Since you don't have a scope yet, there is no sure way of telling whether you'll even have a noise problem or whether the bulk of the noise will be in the same frequency range. However, should you decide to buy these probes anyway, as far as quality, they will surely beat the stock Owon probes.
Another thing to keep in mind is that a 6" ground wire doesn't provide accurate readings for high frequencies and fast rising signals. This is true regardless of whether the scope produces noise like the Owon or is squeaky clean. So the 6" ground wire should only be used for low frequency work with any scope. If you plan to stick to these rule, you can dramatically reduce the noise from the Owon when using the 6" ground lead by turning on the 20MHz bandwidth limit. If you are working with even lower frequencies and small signals, you can also set the stock Owon probe to X1, which limits the bandwidth to about 6MHz.
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Except the Owon probes, I have a Hameg HZ-36 Probe with 12/57 capacitance and another germany one (no name) with 11/46 capacitance (1:1/1:10 both).
Neither one has a better behaviour on gnd noise than Owon stock. For my probes, as the capacitance is lower as worst be the gnd noise!
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Except the Owon probes, I have a Hameg HZ-36 Probe with 12/57 capacitance and another germany one (no name) with 11/46 capacitance (1:1/1:10 both).
Neither one has a better behaviour on gnd noise than Owon stock. For my probes, as the capacitance is lower as worst be the gnd noise!
I'm curious, have you used the FFT to check the frequency range of your Owon's noise. On mine the bulk of the noise is around 100MHz. Given your results, I suspect the bulk of the noise on your scope is at a higher frequency.
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Here are two captures, one of them is "gnd noise" and the other the same time what is appearing the FFT...almost 100MHz.
The test was done by Owon probe.
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Here are two captures, one of them is "gnd noise" and the other the same time what is appearing the FFT...almost 100MHz.
The test was done by Owon probe.
Thanks a lot for the images. From your FFT image I can see that the noise on your scope is a little different than mine. Yours has almost even noise from about 80MHz to 140MHz. That explains to me why you don't see much difference using lower input capacitance probes. Here are some similar images from my scope using both the stock Owon probe and a 9.5pF input capacitance Tek probe. As you can see the noise improves with the lower capacitance probe, but the noise in my scope peaks at 100MHz unlike yours.
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Here are two captures, one of them is "gnd noise" and the other the same time what is appearing the FFT...almost 100MHz.
Yours has almost even noise from about 80MHz to 140MHz. , but the noise in my scope peaks at 100MHz unlike yours.
Hey Guys,
That looks like FM Radio Stations,
Maybe try it in Faraday cage, metal Filing cabinet w/screen on front
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What do you think about an "alternative ground tip" like this:
http://www.ebay.com/itm/100-Pcs-Silver-Tone-Connector-Clasp-Ball-Chains-Keychain-Tag-10cm-3-7-8-/251276885018?pt=US_Unisex_Accessories&hash=item3a8144fc1a (http://www.ebay.com/itm/100-Pcs-Silver-Tone-Connector-Clasp-Ball-Chains-Keychain-Tag-10cm-3-7-8-/251276885018?pt=US_Unisex_Accessories&hash=item3a8144fc1a)
can reduce the noise on Owon SDS7102 ?
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Here are two captures, one of them is "gnd noise" and the other the same time what is appearing the FFT...almost 100MHz.
The test was done by Owon probe.
Thanks a lot for the images. From your FFT image I can see that the noise on your scope is a little different than mine. Yours has almost even noise from about 80MHz to 140MHz. That explains to me why you don't see much difference using lower input capacitance probes. Here are some similar images from my scope using both the stock Owon probe and a 9.5pF input capacitance Tek probe. As you can see the noise improves with the lower capacitance probe, but the noise in my scope peaks at 100MHz unlike yours.
From what I have seen the noise is depends from schema of Probe Cable.
The probe cable is working like antenna and catch everything!
Because my english is not well, here is a video with above thought. There is a noise profile and how this changed by schema of probe cable. At the same time an fft seems the same thing...
My top of noise curve is under of 100MHz (almost 90MHz) and the pattern is don't like yours.
The test was done with Owon Probe and very quickly without any warming of unit, because I have an open unit because failure of fan. If you wish I can take two captures by an other probes.
noisefft (https://www.youtube.com/watch?v=R5c1QNiBnQo#)
What do you think about an "alternative ground tip" like this:
http://www.ebay.com/itm/100-Pcs-Silver-Tone-Connector-Clasp-Ball-Chains-Keychain-Tag-10cm-3-7-8-/251276885018?pt=US_Unisex_Accessories&hash=item3a8144fc1a (http://www.ebay.com/itm/100-Pcs-Silver-Tone-Connector-Clasp-Ball-Chains-Keychain-Tag-10cm-3-7-8-/251276885018?pt=US_Unisex_Accessories&hash=item3a8144fc1a)
can reduce the noise on Owon SDS7102 ?
Tips like this reduce the noise per 90%. As ground clip as close to probe tip, the noise is decreased.
(http://blog.hameg.com/wp-content/uploads/2012/10/Tastkopf1.jpg)
(http://i.stack.imgur.com/8dDrt.jpg)
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From what I have seen the noise is depends from schema of Probe Cable.
The probe cable is working like antenna and catch everything!
Because my english is not well, here is a video with above thought. There is a noise profile and how this changed by schema of probe cable. At the same time an fft seems the same thing...
My top of noise curve is under of 100MHz (almost 90MHz) and the pattern is don't like yours.
The test was done with Owon Probe and very quickly without any warming of unit, because I have an open unit because failure of fan. If you wish I can take two captures by an other probes.
Yes, part of the noise is radiated and part of it is conductive. There is a lot of radiated noise around the scope's TFT panel, so when the probe cable is near the panel a lot of this noise is visible. Also, when you touch the cable with your hands your body becomes part of the antenna with both capacitive and inductive components. As a result the visible noise may increase or decrease depending on how you hold or arrange the cable. Some of the noise you see when holding the cable is not necessarily originating from the Owon. I have several computers in my electronics shop and I can see this noise change depending on my location in respect to the computers, specially laptops with external Switch Mode Power Supplies.
Regardless of whether the noise is radiated or conductive, all I see is common mode noise converted to differential noise when a long ground lead is used with the probe. The radiated noise can be avoided most of the time by keeping the probe cable away from the Owon and other noise sources and avoiding touching it. If this is not possible, sometimes I use ferrite cores on the probe cable to decrease the influence of the radiated noise and a little of the conductive noise. But none of this is usually required if a short ground is used. Here are some images illustrating some of this:
1. The effect of having the probe cable next to the scope's TFT panel with no ferrite cores on the probe cable and using a long ground.
2. The effect of having the probe cable next to the scope's TFT panel with no ferrite cores on the probe cable and using a short ground.
3. The effect of having the probe cable next to the scope's TFT panel with ferrite cores installed on the probe cable and using a long ground.
4. The effect of having the probe cable next to the scope's TFT panel with ferrite cores installed on the probe cable and using a short ground.
5. Illustration of the Owon scope probe with ferrite cores installed on the cable and the fixture I used to connect the probe's tip & ground ring to the scope ground.
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Teorically a good probe must be shilded to prevent any interference (EMI) ??
Why the ground wire have often (or always)a thin section and not a robust section to help the conductivity and shielding ?
P.S.
I see an interested article that affirm that if you apply a ferrite on AC power supply cable this can reduce the common mode noise. Someone can test it with the the Owon SDS7102 ??
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Teorically a good probe must be shilded to prevent any interference (EMI) ??
Why the ground wire have often (or always)a thin section and not a robust section to help the conductivity and shielding ?
P.S.
I see an interested article that affirm that if you apply a ferrite on AC power supply cable this can reduce the common mode noise. Someone can test it with the the Owon SDS7102 ???
The probe's coax wire used is a compromise between appropriate shielding and practical size and flexibility that you can get with available materials. If you used very large gauge wire and shield you could get better common mode rejection, but is not practical. Usually this is not a problem since the scope's input amplifier is designed to respond to differential signals only, so the common mode noise, as long as it remains common mode, is invisible to the scope's input amplifier. When you add other components to the coax wire, e.g. a long ground lead, the external reactance causes an imbalance and part of the common mode noise gets converted to a differential signal. Once it is in differential form it will be visible on the scope.
The long ground wire is intended for low frequency use and is made thin and flexible for ease of use. For low frequency applications you can use other means for reducing noise such as limiting the bandwidth and/or using average mode. There are special ground adapters that use low inductance conductors for high frequency applications. But these, by necessity, are usually small and not flexible. I have experimented with designing a longer low inductance ground wire for my convenience. One approach I used was using de-soldering wick, which is flat, as a conductor. However, the benefit was small because I couldn't reduce the inductance enough to make a big difference.
I have tried one or more ferrite cores on the Owon's power cord to reduce common mode noise produced by other nearby equipment from entering the Owon. In my particular environment, the only time this made a difference, is when I had a very noisy switch mode power supply connected in the same outlet as the Owon.
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Ferrites on probe cable act as low-pass filter. For higher frequency use, short ground tip is to be used.
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Ferrites on probe cable act as low-pass filter.
I'm curious. Have you tested this? If so, at what frequencies did you find this effect? I have compared the frequency response of the probe with ferrite cores illustrated on my previous post with an identical probe without ferrite cores. Through the frequency range I used for my test, 30MHz to 110MHz, the response was identical. So, at least, in this frequency range, there is no low pass effect for differential signals. Of course, if you are talking about common mode noise/signals, I agree there is a low pass effect. But then, that is the point of using the ferrite cores, to help block high frequency common mode noise.
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Someone have tested the difference with inside battery (Owon have it as optional) or eventually plug the AC oscilloscope cable on UPS for PC ?
There are opinions that affirm the common mode noise can be decresed on some of this ways ...
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Mine SDS7102V has this optional and the result is worst!
Look at the attachments captures.
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At this point the problem seem independent by the power supply if with battery is worst...
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At this point the problem seem independent by the power supply if with battery is worst...
No.
I recommend you take some time now and really read all information about this issue and filtrer also out all this "information" what only mix and shake this case.
Also it is good to read some amount theory for understand these things so that all is not so much just "magic" things.
If "lemon" show this last image so that mains power is disconnected and scope run using battery, situation and noise is different.
With battery AND mains power together produce more noise and this noise component what rise is main PSU flyback circuit noise.
I repeat it agen here and agen with some different words.:
Inside scope there is several noise sources. And all noises is conducted to different parts with radiation and conductice, common mode and differential mode. And for understand full case it need understand about RF fields and how RF trawels in different cases and circuits.
Noise "sources":
main PSU
8.4V main PSU flyback converter (1). (severe noise source)
(nominal 8.4V but around over 6V up to to 8.4 if battery) This is master power line and from this is all others derived.
If mains power line is out, battery give this voltage
(1) this is off if only power source is battery.
sub SMPS circuits: (voltages not exactly)
-7.6V (severe)
Adapter board
+5V (moderate - severe)
+3.3V (it seems that this is moderate or less)
TFT back light SMPS (severe)
All these generate high frequency noise in these units what can name real "noisy GND" problem units.
Every these noises have some amount different signature.
All these can separately detected and analysed as example I have done.
These highest spikes in "lemon" last image come exactly from main PSU running flyback converter what produce 8.4V from example 230V Ac or what ever is connected to mains power line.
(these spikes also vary dependent of battery charging sitiuation but they are always more high if battery is installed and powered by mains. (in problem units)
If we look externally oscilloscope whole GND it have sum of these noises and it all is (what are meaningful noises) RF noise from some MHz to over 200MHz. And this we can look that it is "common mode noise". Simplify... it can think that scope GND area works like you have transmitter and it is its antenna. Now you connect wire to it... there start flow RF current to this wire and also it is now part of this "antenna" network. it radiate (meand current flow) and it conduct to places where it is connected... and current flow... etc
But all wires have inductance. You know what happend when RF try go via inductance.... it produce voltage over it...
Oscilloscope probe have also wire.. this coaxial from BNC to probe tip. This RF noise travel via this probe cable and then it travel via this probe separate GND wire and it continue its travel forward to where you have connected it. Important is that in this point where scope probe GND wire is separated (this blacl 15cm wire) there is now This RF travel over this GND wire and RF produce voltage over this GND wire. Yes... this GND wire is short copper wire. How its ends have differet voltage... it is nearly zero ohm. For 100 or 200MHz it not at all "zero ohm..." if it is thinn or thick,, no big change.. if it is gold or iron.. not big difference.. you can coat it by silver.. no big difference (in this case). But if you make it more short... it change radically its inductance and so also reactance. Ferrite over power cord.. yes it is useful but not for this what this probe do. And you can take 1000 euro brand name high-end passive proble and it is more noisy in this case..
Yes your DVM show zero ohm over this short GND wire. But... this wire is inductor...it is coil (without turns) every wire is .. 1cm or 10m have inductance. Independent of if it is cheap Owon wire or expensive Rolls-Royce wire or Tektronix wire.
This RF flow over this wire and it produce voltage over it! And what our oscilloscope show, it show voltage diffrencies between probe tip and probe GND. If you think keep tip in zero potential tightly and then you run signal to GND wire... oops what you see... you see signal.
If think ferrites on power cord or some other place it need understand how they work and how this noise itself.
Primary solution is reduce this noise there where it is produced. (repair these SMPS circuits what are guilty for this)
Secondary solution is try reduce its affect to measurement = do not externally connect this signal to signal under test. And here we can do it with short GND and also get some more help using ferrites over probe coaxial. (2-3 turn thru ferrite example. It may block some amount of this RF noise flow from scope GND via probe cable to probe tip end.
perhaps "lemon" can show how this second picture how it change if take power cord out and run with battery alone. ;)
This proofs that with battery assembled and used with mains power situation is more bad tah mains alone without battery os with battery alone without mains power.
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If "lemon" show this last image so that mains power is disconnected and scope run using battery, situation and noise is different.
I must suppose yes, otherwise what type of test is this ?? Don't have sense ...
I' am curious about this.
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Long time did not visit the forum.
I looked around the circle are the same questions that have been resolved for another 60 pages.
It is clear that the device is a toy and no one at the factory will not fix noise. There is a scheme for modification from rf-loop and there is no nothing difficult. The issue of noise is closed by soldering 10 items.
rf-loop is there statistic how many users have repaired noise by themselves?
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This scope might be good, but always test it well before buying.
This means never buy from eshops!
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To rf-loop,
If I have understand to solve definitively the problem is suffcient replace the mettalic pillar with an equivalent nylon pillar as showed on the picture ??
Seem very easy if is true.
No other actions need ??
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I'm not rf-loop, but I have answer to that:
What you have is instruction on how to solve noise only on channel 1 for some older units from the end of 2011. On newer scopes, the pillar is already nylon and current issue is not channel 1 noise issue.
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To rf-loop,
If I have understand to solve definitively the problem is suffcient replace the mettalic pillar with an equivalent nylon pillar as showed on the picture ??
Seem very easy if is true.
No other actions need ??
may I ask what is idea for mix and shake.
This was old totally different case. This is for OLD CH1 noise issue what was looong time ago solved by Owon and after then I do some help instructions for some peoples who want do this themselves.
This problem start when Owon change whole front end construction and example in lab tests it did not show this noise at all. (if it was disassembled as service run position)
Soon there come information about CH1 special noise. Nearly as soon as it was finded Owon find solution in they test lab. (inside shielded front end metal pillar connects to very sensitive amplifier ground area))
This was simple case.
But I do not understand why you now want pick up this old different issue to here - this new noise issue is enough complex without any extra mixing and shaking.
Did you read what I have told about this new noise issue - my english is bad but I think this not now reason for misunderstooding?
Also other peoples have explained this case very well.
Just ago I explain (agen, just for you) where is this problem now...
And now agen: Problem is in Adapter board SMPS circuits and PSU board SMPS circuits. AND they need repair - modify!
Owon have also made changes and new equipments from factory are now normal afaik. Also I have these normal units directly from factory.
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Owon have also made changes and new equipments from factory are now normal afaik. Also I have these normal units directly from factory.
If possible, can you do a statistic about the last 2 months how many units are "normal" and how many still have the problem ?
If I have understand there are some improvement by owon.
Sometimes on the forums there are informations not updated.
I suppose the new "defected" units can be "better" then the previous "defected" unit ?
If possible, can you attach some screenshots of a new factory (last release) "Normal" and "defected" unit.
I like to known in what measure a new "defected" unit differ by a new "Normal" units.
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I was find myself the response ( I think):
http://owon.forumup.com/viewtopic.php?t=177&mforum=owon (http://owon.forumup.com/viewtopic.php?t=177&mforum=owon)
The difference is huge !!!
I like to know how many are defected (in percent if possible).
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If "lemon" show this last image so that mains power is disconnected and scope run using battery, situation and noise is different.
I must suppose yes, otherwise what type of test is this ?? Don't have sense ...
I' am curious about this.
Unfortunately, mine situation is different from what we are expected!
With well charged battery from the worst to best the sequence is: battery (?400mV), battery+ac main(?300mV), ac main (?150mV) - Cheked by Owon Probe after Self Cal procedure and Probe adjustment.
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My concern isnt' the gnd noise of this unit.
With an appropriate procedure this can eliminated. In the worst case will need to purchasing two boards (with some discount).
My concern is its fw.
Almost one year from bought this and there is a small improvement without fantasy and taking serious the various reviewer suggestions.
I have no see errors, yet and that's why I believed that is matter of time the improvement of sw.
Unfortunately time did not verified me.
Good hw but average sw!
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Unfortunately, mine situation is different from what we are expected!
With well charged battery from the worst to best the sequence is: battery (?400mV), battery+ac main(?300mV), ac main (?150mV) - Cheked by Owon Probe after Self Cal procedure and Probe adjustment.
Yes, this is unexpected result.
I have seen before:
(a) battery+ac most bad,
(b) ac without installed battery (battery out) less than a
(c) with battery alone without ac connected, less than b
It need some more investigation. I have some small suspects but too early to say.
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With an appropriate procedure this can eliminated. In the worst case will need to purchasing two boards (with some discount).
Can you please explain better this concept ??
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Unfortunately, mine situation is different from what we are expected!
With well charged battery from the worst to best the sequence is: battery (?400mV), battery+ac main(?300mV), ac main (?150mV) - Cheked by Owon Probe after Self Cal procedure and Probe adjustment.
Yes, this is unexpected result.
I have seen before:
(a) battery+ac most bad,
(b) ac without installed battery (battery out) less than a
(c) with battery alone without ac connected, less than b
It need some more investigation. I have some small suspects but too early to say.
Yeap, it is very strange and I have no the knowledge to explain it.
You have my revisions of boards (p.m at yours forum)...
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With an appropriate procedure this can eliminated. In the worst case will need to purchasing two boards (with some discount).
Can you please explain better this concept ??
I think, that you are member of "Electronics and Owon SmartDS oscilloscopes Forum".
At the two of these forums, there are discussions who described the issue very well and suggests methods or mods for eliminate this issue.
Methods with a short gnd distance or mods to main psu or adapter plate.
At pages from 51 and so on of this forum, you can find some of this methods and mods.
Sorry but my english, is very few to explained this better.
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I hope with new or future units don't need any mods.
The point that is it not clear and WHEN you can purchase a new unit without worries to ask the seller to test it before buy.
If there is a response about this question all problems are deleted.
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My concern isnt' the gnd noise of this unit.
With an appropriate procedure this can eliminated. In the worst case will need to purchasing two boards (with some discount).
My concern is its fw.
Almost one year from bought this and there is a small improvement without fantasy and taking serious the various reviewer suggestions.
I have no see errors, yet and that's why I believed that is matter of time the improvement of sw.
Unfortunately time did not verified me.
Good hw but average sw!
Yes, IMO this is rather a problem with Owon. Forgetting for a moment the current noise issue, the SDS series has always been an interesting and well-thought-out hardware solution for the low-cost DSO market - and I appreciate that they've improved the HW in the two years since the series was introduced to Western markets. But from what I can tell, they've done very little extra work in the FW department (yes, I know they fixed some bugs, of course).
But considering all of the feedback from (and desires of) it's customer base that exist all over the Net, you would think that Owon might have added ONE important new feature - or even drastically changed the behavior of ONE old feature that customers didn't like.
Have they done this? Not that I've read about - although I could be wrong. Current owners are welcome to post information to the contrary.
OTOH, even Rigol - another Chinese company which is not very responsive to it's customers - has managed to, in their latest FW (for a product which is less than 1 year in Western markets) drastically change the behavior of a feature which many of us customers were complaining about.
I think Owon needs to rethink where they focus part of their attentions. Some times good PR (responding to customers desires) is as helpful to sales and good will as improving BW response by another db.
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The Owon SDS series went to market in early 2011 and there are problems with noise even today, while 2011 scopes didn't have this problem... :-- Well, buy Rigol instead. :palm:
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The Owon SDS series went to market in early 2011 and there are problems with noise even today, while 2011 scopes didn't have this problem... :-- Well, buy Rigol instead. :palm:
What are you adding to this discussion? You just seem to be interested in posting as often as possible to raise your number of comments. The members having this discussion are former/current/prospective owners of the Owon SDS DSO - of which you are neither. Of course, that wouldn't preclude you from contributing if you had some new perspective or information to add to the discussion - but that's not what you're doing.
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GND Noise continuety...
At page 65 the member alexuresp shows an inside ferrite filtering the cable between main psu and adapter plate.
One other member found a small improvement by this method (I think that was Siri).
I decided to experiment about this with a clip cylindrical ferrite (see attachment photo).
My gnd noise is almost 145-160mV normal.
After this small mod the level noise was done 68-96mV! Eeep! This is not a small improvement, it is a huge! And all spikes has gone completed!
The next mod is more ferrites to probe (see attachment photo), after this the range of gnd noise is 38-56mV very well! (see attachment photo)
Also with only battery (no ac mains attached) the noise from 400mV drops to 106-110mV (see attachment photo).
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Very interested !!
Do you think to try to find other "easy" MOD like this ?
The difference is HUGE, but a "normal" unit have less noise.
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Yes the improvement is huge!
I don't know how is the level of gnd noise of the new Owon units. Probably the rf-loop can to feedback us.
Works very fine, look at vertical shift so that bottom of square can see. Very thin at 10M length!
I am waiting the opinion from more knowledge members than me.
I don't know if this is an exception that works only to me, but I am happy for the results!
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I think the results is very well. I done a compare between "long gnd cable" and "short gnd"
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Probe 10:1, Signal 10kHz, sine, 200mVpp, Probe connected to signal output and probe normal GND wire to signal source GND.
Probe 10:1, Signal 10kHz, sine, 200mVpp, Probe tip connected to signal output. Probe GND directly to signal source GND. (without "long" GND wire)
Probe 10:1, Signal 10kHz, sine, 30mVpp, Probe connected to signal output and probe normal GND wire to signal source GND (long gnd).
Probe 10:1, Signal 10kHz, sine, 30mVpp, Probe tip connected to signal output. Probe GND directly to signal source GND. (without "long" GND wire)
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Good findings.
Yes with these methods can reduce noise but now need also note that "lemon" oscilloscope PSU and Adapter boards are different versions than this perhaps more "famous" later manufactured noisy version.
But blocking common mode high frequency noise, one important thing is "close" these noise roads with ferrite. This solution is "attenuate" noise. But still these circuits make this noise, only some roads are now "attenuated".
Perhaps wise words: "do not make noise what then need attenuate or isolate."
But this method can use if want easy reduce this noise so that it do not so much pollute signal when use probe.
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How to regognize from total noise different fractions and where from these come.
There is simple method. (of course it need oscilloscope is opened.)
(testing running scope internals need careful becouse this method use scope itself for this work)
There need two probes.
One probe, CH1, for just tip and GND longwire connected to scope internal base plate (Z-plate) near main board side. Select V/div for good visible noise.
Other probe to CH2... take GND wire out and take hook out. Insert some isolation tube over probe tip and GND area so do not need afraid short circuit. (it is now just as capasitive probe.. it is enough for pick-up these noise spikes.
Select CH2 for trigger!
Take example PSU -7.6V SMPS and pick up stabile trigger so that keep probe "capasitive" tip example near this SMPS inductor or flywheel diode.
Look now CH1 signal... adjust horixontal speed for good visibility. Now these peaks what are from this -7.6V SMPS are locked to trigger and other peaks run randomly... peaks what do not walk left or right on the screen are coming fronm this circuit.
With this method there can regognise all SMPS noise peaks... next TFT back light circuit on the adapter board ... and of course PSU board main flyback ... CH2 probe near flyback transformer or secondary side double diode heatsink.
small exercise and find good settings...
Soon it can know what peak come from what circuit.
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I don't know if this is an exception that works only to me, but I am happy for the results!
I've been thinking of trying this approach myself, but haven't opened the scope yet since it's only a few months old. Using ferrites to filter conductive noise and shields to isolate radiated noise is an approach used by manufacturers to salvage production boards that don't meet noise requirements. It doesn't fix a bad design, but allows their product to pass noise requirements without the expense of a full redesign. I would expect this approach to reduce the common mode noise of most Owon scopes suffering from the current noisy GND problem, not just yours. I have seen ferrites specifically designed to fit flat cables. When I try this approach in the future I will probably purchase ferrites of this type.
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Yes the improvement is huge!
I don't know how is the level of gnd noise of the new Owon units. Probably the rf-loop can to feedback us.
Works very fine, look at vertical shift so that bottom of square can see. Very thin at 10M length!
I am waiting the opinion from more knowledge members than me.
I don't know if this is an exception that works only to me, but I am happy for the results!
Good work Lemon! Although my unit predates the ones with the severe noise it still has some and I was thinking of trying this after seeing Siri's post. I'm sure I'll give it a try now.
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This is a big improvement !!
However can be interested if for example another ferrite to other internal part can "complete the work" or another "easy" mod.
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...
---------
How to regognize from total noise different fractions and where from these come.
There is simple method. (of course it need oscilloscope is opened.)
(testing running scope internals need careful becouse this method use scope itself for this work)
There need two probes.
One probe, CH1, for just tip and GND longwire connected to scope internal base plate (Z-plate) near main board side. Select V/div for good visible noise.
Other probe to CH2... take GND wire out and take hook out. Insert some isolation tube over probe tip and GND area so do not need afraid short circuit. (it is now just as capasitive probe.. it is enough for pick-up these noise spikes.
Select CH2 for trigger!
...
With in my mind, what are suggest the rf-loop, I examined the main psu of my oscilloscope.
My psu version is PCB-T115-J REV6 with:
IC1 = R7731 Burst Triple Mode PWM Flyback Controller
IC2 = LM324L-S14_Quad Operational Amplifiers
IC3 = MC34063A-D 1.5A Step up_Step Down Inverting Switching Regulator
With the probe to air, the noise level is almost 218mV with a lot of spikes (see the first attachment photo).
With the probe 5cm over the psu board the noise is 510mV. A lot of psu rf noise (see the second attachment photo).
With the probe over to IC1 (see the third attachment photo).
With the probe over to IC2 (see the fourth attachment photo)
With the probe over to IC3 (see the fifth attachment photo)
With the probe over to switch J2 (a lot of noise) (see the sixth attachment photo).
What I am thinking about all these.
First I am thinking to apply a decouple filtering with Oscon capacitors between the vcc and gnd each IC.
Second I am thinking to make a metal safety cage that include the psu board.
What are you thinking about these?
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Please use png for printscreens and keep them 800×600 pixels.
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What are you thinking about these?
Your efforts and your willingness to share are appreciated, keep up the good work. Using good quality decoupling capacitors may help, a faraday cage as you describe may also be a good idea. Your posted images could be sharper if you used PNG instead of JPG. I use Irfanview free software to do the conversion from BMP to PNG.
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There was a lot of compression with the conversion from bmp to jpeg. You have right the next images will be png.
I am thinking to change all the electrolytic capacitors (from what I have seen all of them are decoupling capacitors) with other with a low esr. The Owon used cheaper electrolytics capacitors here.
I'll come back with news...
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There was a lot of compression with the conversion from bmp to jpeg. You have right the next images will be png.
I am thinking to change all the electrolytic capacitors (from what I have seen all of them are decoupling capacitors) with other with a low esr. The Owon used cheaper electrolytics capacitors here.
I'll come back with news...
Low ESR capacitors are good for audio applications, however, it's dubious if they will be of benefit for decoupling frequencies in the MHz range. But if you have some on hand you can try and see what happens. You may also want to try small mica capacitors in parallel, I've seen this often used to decouple high frequencies.
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There was a lot of compression with the conversion from bmp to jpeg. You have right the next images will be png.
I am thinking to change all the electrolytic capacitors (from what I have seen all of them are decoupling capacitors) with other with a low esr. The Owon used cheaper electrolytics capacitors here.
I'll come back with news...
Low ESR capacitors are good for audio applications, however, it's dubious if they will be of benefit for decoupling frequencies in the MHz range. But if you have some on hand you can try and see what happens. You may also want to try small mica capacitors in parallel, I've seen this often used to decouple high frequencies.
This whole ESR "issue" is good to understand becouse too much hypes about esr...esr...esr...esr...
It need only once read one theory book and look real data about example different capasitors impedance/reactance curves related tro frequency.
As also it can see in DIY modification instructions version 2b.
(of course everyone can do own tests and also try how much low ESR electrolytic itself help but... perhaps there loose only time and material... but of course longevity may be improved using high guality electrolytics)
Specially there can see how 5V and 3.3V SMPS are bypassed (and note, both sides - SMPS input and output need!) by ceramic capacitors and as near as possible also to reduce inductances on the board. And also, why parallel more than one... perhaps I did not have enough big capacitors. No. It is becouse different capacitor have different resonant frequency. Becouse I did not have in this point expensive good componenst for this, I use this method. And note, it was experimental work for find solution and also there was busy. (also in this time owon was waiting and need fast find some iportant keypoints for solve this problem. Then DIY version is derived from these experiments.)
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Specially there can see how 5V and 3.3V SMPS are bypassed (and note, both sides - SMPS input and output need!) by ceramic capacitors and as near as possible also to reduce inductances on the board. And also, why parallel more than one... perhaps I did not have enough big capacitors. No. It is becouse different capacitor have different resonant frequency. Becouse I did not have in this point expensive good componenst for this, I use this method. And note, it was experimental work for find solution and also there was busy. (also in this time owon was waiting and need fast find some iportant keypoints for solve this problem. Then DIY version is derived from these experiments.)
This is excellent insight on the many ways resonance or inductance of components (including printed ckt board traces) can influence the EMI of a circuit. I suspected you had some components stacked in the DIY because of this reason, but its good to post it so others know.
My scope is only a few months old, so I don't want to void the warranty with your DIY solution. When the scope is a little older and I trust the mayor components will survive the warranty period, I'll probably be more adventurous and try this solution. Lemon's scope is older and is already open because of a fan failure. So, I'm interested to see if he can improve the noise problem with solutions that are not likely to void the warranty, like ferrite cores and/or shields.
Personally I find the ground noise problem to be just an inconvenience. I only have to use the same probing methods and cautions that I would have to use anyway if the Owon was squeaky clean but the equipment under test was noisy. Still, I'm disappointed that Owon is unwilling to admit the problem publicly and offer a solution. I have contacted them via their chat/e-mail about this problem and they won't even respond. This attitude is not conducive to trust and good faith, which in their own words is supposed to be their motto.
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I'm disappointed that Owon is unwilling to admit the problem publicly and offer a solution. I have contacted them via their chat/e-mail about this problem and they won't even respond. This attitude is not conducive to trust and good faith, which in their own words is supposed to be their motto.
It's a shame. I had another problem, I also contact them by email and did not even respond. :-//
"Meet your best need" :palm:
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It is very strange.
I had contact twice with them and their respond was very quickly!
The smd solution by rf-loop is the best approach to eliminate the gnd noise. He has investigate this solution and works fine! I have all electronic material and the appropriate technical knowledge how to do, but my oscilloscope is under of warranty and I am afraid!
Unfortunately, the Owon politic isn't clearly about this issue and how they think to offer us a solution in future.
If the offer will be a new psu and adapter board with some discount of course, for me there is no any problem to apply the rf-loop solution now.
I will experiment with some ferrite at the cable of boards and probes (I am waiting some of them) and I am thinking to make a Faraday cage by metallic mesh for the psu board.
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They've responded only to some of my questions, respond according to their interest.
When the fan started to making a strange noise, I ask for a spare part and I got no response.
Even I offered paid the postage and the part, but nothing. :--
I'm sure, a ferrite will help to decreasing the noise. I think too that a Faraday cage for the psu board, help.
rf-loop says: "do not make noise then what need attenuate or isolate."
I see it hard, if all DC/DC converters generate noise within the same band, it would be easy to filter (input and output), but this is not the case, and -7.6V SMPS need a better filtering.
This problem needs a total redesign of the main PSU and "power subcircuits DC/DC", including the TPS40222 on the main board.
I don´t understand to OWON, spending a little more would have been a good oscilloscope. :-//
I think that the smd solution by rf-loop is cheap, but not the best to eliminate the gnd noise, no doubt he has investigate this. But is OWON who should fix it, and offer a new psu and adapter board for free or with some discount, because many of us surely we would be willing to pay for it.
I don´t understand to OWON...
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Well, it might be easy and cheap to buy a suitable fan. Or does Owon use a special one?
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They've responded only to some of my questions, respond according to their interest.
When the fan started to making a strange noise, I ask for a spare part and I got no response.
Even I offered paid the postage and the part, but nothing. :--
I'm sure, a ferrite will help to decreasing the noise. I think too that a Faraday cage for the psu board, help.
rf-loop says: "do not make noise then what need attenuate or isolate."
I see it hard, if all DC/DC converters generate noise within the same band, it would be easy to filter (input and output), but this is not the case, and -7.6V SMPS need a better filtering.
This problem needs a total redesign of the main PSU and "power subcircuits DC/DC", including the TPS40222 on the main board.
I don´t understand to OWON, spending a little more would have been a good oscilloscope. :-//
I think that the smd solution by rf-loop is cheap, but not the best to eliminate the gnd noise, no doubt he has investigate this. But is OWON who should fix it, and offer a new psu and adapter board for free or with some discount, because many of us surely we would be willing to pay for it.
I don´t understand to OWON...
This "do not make noise what then need isolate or filter" means that need design SMPS circuits with good design practices so that they do not produce noise. This is primary rule. Secondary thing is then filter and isolate rest for make real "silence". This is good rule for acoustic noise (exaple motors) and for electronics, example PSU.
Example this experimental what I have done with PSU and Adapter board, it is only just some "what can do easy". It is NOT solution for this. These boards topology need radically change before it is good.
Today I do not know what kind is Owon new PSU what is going to mass production somewhere around start of June. And what changes they have made for adapter board (what is still more easy).
About fan. Just I heard one person who have bad fan and he call Owon and no any problem. Owon send new one.
If you have warranty failure in your scope, ask Owon start RMA procedure for get it repaired.
(in case that you have international "overseas" warranty.) Of course primary roadmap is contact seller. Why he sell these if he can not give any kind of after sales customer care. Or was he only "box shipper". If this is case... you have get what you have paid. If example my customer is troubles (example failed fan) and if he want new fan from Owon and he want himself change it. If in this case Owon do not help him I take contact to Owon an ask this help to him. You know, all this is work. More or less. But my customers have allready paid some amount of after sales customer care.
Common opinion
I wonder more and more this situation. Peoples buy from whoever box shipper example oscilloscopes. This box shipper seller do only that he receive boxes wrom some source and then he reship these to customers who buy. Then, what ever happends these customer are alone. Thenh all these customers want help directly from factory.
What other business go like this? Buy bicycle... if troubles, who help... factory? If buy car, then some trouble... customer call with phone or letter to factory who have made this car? ... you buy Sony or Lg TV and then there is problem... all peoples call directly to factory?
Oh boys this do not work...
Some yars ago I buy camera, Canon.. then there was problem with it. Oh yes I send letter to canon factory secretary and ask factory help me. No no.
I call to seller and ask help. Kindly seller tell me how to do do.
I do not understand how this oscilloscope or other measurmenet equipments situation have gone to this position where we are now.
I have one recommendation to Owon. This is public recommendation.
Do not sell these equipments to "whoever".
Sell these only to these distributors who really also do they jobs and add some value to product. Product is more than only box. It include box itself but also some kind of pre- but more importantly some kind of aftersale customer care - even some amount. Just like some brands do.
Stop totally this wild markets!
Then give all and full support for distributors - even some spare part lots. Even some teaching about products and some basic service information so that distributors really can give after sales support and add some value to product.
Organisation where all can be reseller (or better say: box shippers) and then all end users ask customer care from factory - in long run it is road to dead. It do not work. These box shippers can not give any value to end users. They make only finally this all business impossible.
If do not want this solution where all win. Triple win. Customer win. Dealer-distributor win and Owon win in long run.
In other case it is best that only who sell these directly to end user is Owon itself. And same recommendation to many other manufacturers. You need develop organisation.
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Well, it might be easy and cheap to buy a suitable fan. Or does Owon use a special one?
Fortunately yes, is easy and cheap to buy a suitable fan. But is this the reason for not given answer to a client?
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Reply #1180 on: Today at 01:10:46 AM
rf-loop, totally agree this time ;)
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Probably, yours fan noise is from fan blades that hitting to metal corners.
Open the unit and look if the fan is centered OK!
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Well, it might be easy and cheap to buy a suitable fan. Or does Owon use a special one?
Fortunately yes, is easy and cheap to buy a suitable fan. But is this the reason for not given answer to a client?
Of course this is not answer to client specially in situation where warranty is ok.
Of course IF customer ask, there can give help information what is suitable fan.
As far as I know, Owon also repair machines where is not warranty. In this case customer ned pay. (shipping is in this case prhaps primary cost)
Owon can also sell spare parts if needed. If you drop your oscilloscoe and display breaks. You can buy new display module from Owon and if some knobs also broken, just add these also to buy list.
And small example in service manual:
Fan: JD-6010S1MO
LCD: AT080TN52
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Yes, rf-loop you have right!
From what I have seen from SDS Series Oscilloscopes Service Manual v1.0 there is a table with replaceable parts. I attached this section.
Still, main psu and adapter boards are replace-ables...
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Yes, rf-loop you have right!
From what I have seen from SDS Series Oscilloscopes Service Manual v1.0 there is a table with replaceable parts. I attached this section.
Still, main psu and adapter boards are replace-ables...
New service manual is V1.2 (made 2013)
if I remember right this tble is still same but other information some more.
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Today I do not know what kind is Owon new PSU what is going to mass production somewhere around start of June. And what changes they have made for adapter board (what is still more easy).
It's a shame that they don't keep you better informed about their progress on this issue. After all, I doubt that any other dealer has done as much to help solve this problem and to quiet down the flames from dissatisfied customers. However, knowing that they will start mass production sometime during early June may be useful information. I for one plan to contact them again during this period and ask for replacement boards, whether free or at a discount. At this point I feel that any kind of a response or offer would be better than this deafening silence. Perhaps others interested in a resolution should also contact Owon during this period, whether for the first time or for the umpteenth time if you got no response before!
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Hi, everybody.
I think so that the fan of my SDS7102 has gone.
I can't hear it (and I don't remember if it is hearing in past) and the front part of oscilloscope is warming!
...
Today, Owon has sent me via DHL the new fan spare.
It was totally free from import taxes and fees!
I appreciated this quick supporting!
I sent at 20 May the problem at their chating room and today the spare comes to my door!
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I'm glad for you lemon!
Why I was not so lucky? |O
I really do not understand to OWON.
After many messages to OWON I get an answer, email reply (sales01@owon.com.cn):
"Dear Sir,
Thank you for purchasing OWON product.
Sorry,we have not sell FAN.
Best regards
Kim"
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Today, Owon has sent me via DHL the new fan spare.
It was totally free from import taxes and fees!
I appreciated this quick supporting!
I sent at 20 May the problem at their chating room and today the spare comes to my door!
I will look at this as an omen, that maybe Owon is becoming more receptive to customer needs. This further encourages me to contact them again about the GND noise problem and ask for new boards. Good luck with repairing your scope!
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I'm glad for you lemon!
Why I was not so lucky? |O
I really do not understand to OWON.
After many messages to OWON I get an answer, email reply (sales01@owon.com.cn):
"Dear Sir,
Thank you for purchasing OWON product.
Sorry,we have not sell FAN.
Best regards
Kim"
It is strange!
Because English is not the native language nor us nor the Chinese, sometimes we do not understand what to say.
I do not know how you described your problem, but if they understand that you just want to buy a new fan probably their answer is correct.
Suggest three possible solutions:
1) To re-submit the problem.
2) ?o open the unit and look the fan according what we suggest you (fan centered, fan in properly position e.t.c)
3) Changed the fan alone. From what I saw is not something special, a simple fan that operates silently due to low supply. If you can't find fan with the same connector, cut the old connector and put it to new one.
A latter addition-1 = a fan picture from an older message from member cex (at page 34)
Some guide from assemby the unit, scecially from units made at the end of 2011 - first or second Quarterly of 2012.
https://www.box.com/s/pvg1dqtdonx192p4os0m (https://www.box.com/s/pvg1dqtdonx192p4os0m)
(http://i174.photobucket.com/albums/w85/cex123/IMAGE_201.jpg)
A latter addition-2 = Note for FAN (from page 36, aghp member) :
Findings in service:
If you hear some abnormal noise just after start or shaking/turning oscilloscope to different orientation.
FAN maybe positioned just littlebit wrong in factory. It need be enough well centered to air hole in Z-plate. Other way there is possible that fan blade(s) hit this Z-plate edge becouse rotor can move some amount axial direction just enough.
Repair: Loose screws and ceter (it can move enough).
This may also damage fan sleeve bearing. Check. If bad bearing: fan need of course change.
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This fan seem very similar (or identical) to standard PC Fan.
This fit the some size and dimension ?
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The dimensions are: 60X60X11 (mm)
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5$ on ebay:
http://www.ebay.com/itm/1-pcs-Brushless-DC-Cooling-11-Blade-Fan-6010s-12V-60x60x10mm-2-Wires-/160896610367?pt=LH_DefaultDomain_0&hash=item25762f703f (http://www.ebay.com/itm/1-pcs-Brushless-DC-Cooling-11-Blade-Fan-6010s-12V-60x60x10mm-2-Wires-/160896610367?pt=LH_DefaultDomain_0&hash=item25762f703f)
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Today, Owon has sent me via DHL the new fan spare.
It was totally free from import taxes and fees!
I appreciated this quick supporting!
I sent at 20 May the problem at their chating room and today the spare comes to my door!
I will look at this as an omen, that maybe Owon is becoming more receptive to customer needs. This further encourages me to contact them again about the GND noise problem and ask for new boards. Good luck with repairing your scope!
Today I left the following message at Owon's tech support chat room:
Dear Owon Tech support:
This is a follow up to my April 4, 2013 inquiry to which I did not receive a response. I bought my SDS71021246320 from Saelig in the USA on January 17, 2013. As I previously stated this is one of the units that has the "GND noise issue". This is the issue extensively discussed in the EEVblog and ForumUp forums on the internet. A DIY for modifying the PSU & adapter boards has also been posted but unfortunately it voids the Owon Warranty. It's been reported that Owon may be starting mass production of improved PSU and Adapter boards that include this modification during the month of June. I would greatly appreciate a response to the following questions:
1. Will the "GND noise" significantly decrease if these new boards are installed in my unit?
2. Will the Owon Warranty cover replacement of these boards in units affected by the "Gnd noise" issue?
3. Can I obtain these boards so I can fix my scope myself either free under the Warranty or at a discount if this is not possible?
A prompt and detailed response will be greatly appreciated.
Best regards,
--------------------------------------------------------------------------------------------------------------------------------------
If Owon receives enough similar messages from other customers it may help them decide that it is time to publicly state their position on this issue, whatever that is!
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I'm curious for their answer!
I'm quite sure that they have received enough similar messages from other customers.
Until now their answers is almost like that :
"About GND ISSUE, we will solve it try our best in future" or
"Unfortunately, there is no any warranty cover because there is no any effect at measurements by "gnd noise".
I hope, the Owon to has a final proposal to their customers for this issue, now.
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...
With the probe to air, the noise level is almost 218mV with a lot of spikes (see the first attachment photo).
With the probe 5cm over the psu board the noise is 510mV. A lot of psu rf noise (see the second attachment photo).
With the probe over to IC1 (see the third attachment photo).
With the probe over to IC2 (see the fourth attachment photo)
With the probe over to IC3 (see the fifth attachment photo)
With the probe over to switch J2 (a lot of noise) (see the sixth attachment photo).
What I am thinking about all these.
First I am thinking to apply a decouple filtering with Oscon capacitors between the vcc and gnd each IC.
Second I am thinking to make a metal safety cage that include the psu board.
What are you thinking about these?
I done a trial with a metal cage for psu board. Not entire closed, because it is very difficult, but closed to the adaptor board side.
The results is positive, the noise is decreasing by 40%. Probably this eliminate the EMI noise that psu board has, but this is no easy diy solution. The free area of back case is a little and the construction of fully closed cage is impossible!
Finally, the rf-loop or siri diy proposals to circuits is the best approach but have warranty risks.
The most easy approach without warranty risks, are ferrites to all internal cables and probes too.
Except the Owon decides to give us a gift!
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I hope that "OWON" clarify what decision will take. :box:
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I'm curious for their answer!
I'm quite sure that they have received enough similar messages from other customers.
Until now their answers is almost like that :
"About GND ISSUE, we will solve it try our best in future" or
"Unfortunately, there is no any warranty cover because there is no any effect at measurements by "gnd noise".
I hope, the Owon to has a final proposal to their customers for this issue, now.
Apparently Owon hasn't ventured too far from previous statements, here is the response I just got:
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"Thank you for purchasing OWON product.
As to GND noise, we have noticed there is noise, but it is not the one will affect your testing result, as you know, every scope has noise affect by testing environment.
We have not plan and exact date to make change for it now, because it is not quite abnormal. Unlike the ones said in the blog.
Thank you for understanding. "
--------------------------------------------------------------------------------------------------------
If I understand this correctly, they are saying that:
1. They know there is noise.
2. In their opinion the noise doesn't affect testing.
3. That this noise is similar to other external sources of noise you may encounter while using the scope.
4. That making changes to correct this noise is not a priority because it is closer to normal than abnormal.
5. That either the noise they see or the influence they believe it has in the usability of the scope doesn't match what is said about it in the EEVblog.
6. That they are hoping that the customer finds this explanation acceptable.
As I stated before, I view the GND noise on my scope as just an inconvenience. So I can't argue that some of the statements made by Owon are untrue. However, I find it strange and inappropriate, that a test equipment manufacturer would justify an obvious flaw in their equipment by pointing out the existence of external similar conditions that mimic it. Similarly, a car manufacturer could justify a car that pulls slightly to the right on a straight and level road, by reminding the customer that common road conditions would require him to steer in a similar way anyway.
In the end, Owon didn't directly answer the questions regarding Warranty coverage. However, the tone of the message leaves little doubt in my mind that at least at present they don't plan to offer Warranty coverage or any kind of a discount.
Ultimately, Owon will have to live with the results of their actions. Saving a few dollars now may seem as a wise financial decision. But only time will tell the actual cost of disappointing current customers and causing prospective buyers to take pause.
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I emailed Saelig's and was told that the issue is insignificant. Still it is the issue that made me go back to the drawing board and keep looking at scopes a little longer.
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Here also can find some information.
SDS7102"noisy GND" issue. Is it noisy, is it not? (http://owon.forumup.com/viewtopic.php?t=177&start=0&postdays=0&postorder=asc&highlight=&mforum=owon)
Specially last post:
15 May 2013
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Ultimately, Owon will have to live with the results of their actions. Saving a few dollars now may seem as a wise financial decision. But only time will tell the actual cost of disappointing current customers and causing prospective buyers to take pause.
Go to hell, OWON and all who defend it, scammers. :-- :blah: :rant:
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Well, Siglent produces for Atten, BK Precision and LeCroy. Rigol produces for Agilent. Owon doesn't produce for any major brand, so Owon can be considered the lowest quality of these three.
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I want to thank this forum, because somehow allows us to denounce these situations. And thanks also to David L. Jones, for his honesty, informing everyone when "rf-loop" aka "aghp" or "xxxx" had discussions with himself (under another alias) in this forum, probably for their own interest. That says a lot about you rf-loop.
I repeat:
Go to hell, OWON and all who defend it, scammers.
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Well, Siglent produces for Atten, BK Precision and LeCroy. Rigol produces for Agilent. Owon doesn't produce for any major brand, so Owon can be considered the lowest quality of these three.
By that logic, GW Instek is crap too? :-) Trying to understand the logic.
... "rf-loop" aka "aghp" or "xxxx" .... Go to hell, OWON and all who defend it, scammers.
rf-loop is not owon. YES, he pulled a shifty, and got caught :-). We over it yet ? There's a lot of useful info as well, just filter out the stuff you
don't trust / like? After all, this IS the Internet yanno there's lots of bad / misleading / false stuff ALL over it !! True !! I read it !
I have a battery version and use it in the field quite a bit. I've had GND noise problems with ALL my CROs, even my genuine LeCroys !!
IF it IS a problem, I RE-THINK my grounding arrangements, it's what a techie does.
No need to get out the pitchfork and torch yet :-) Play nice please
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I want to thank this forum, because somehow allows us to denounce these situations. And thanks also to David L. Jones, for his honesty, informing everyone when "rf-loop" aka "aghp" or "xxxx" had discussions with himself (under another alias) in this forum, probably for their own interest. That says a lot about you rf-loop.
And tell us also honestly (do you know these words: honest or truth?) what is your real backround and motivation for this bullshit.
Can you show even one example about this total bullshit - even one. And please tell also who is xxxx.
But where is discussion what give some wrong information or keep some fake discussion between two names.
All these my posts can read as long as administrator keep them untouched. Even if someone change these, I have full copy.
Also I have explained bacround of rf-loop / aghp. But perhaps it wast too difficult rocket science?
But one thing I have learned here.
If I see false technical allegations, I no longer try to correct them here, specially depending on who submit false claims.
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I think we need calm, there is no need to characterize each other.
The issue with the member names "rf-loop" & "aghp" I think that has cleared a long time ago AFAIK there is a reference at the signature of rf-loop about this.
My level of english, not allow me to explain it better (as I like it).
The problem for me is the wrong decision of Owon about this issue.
Clearly the noise issue is not major, but affect relatively very low signals.
There is a lot of documentary from rf-loop works.
Of course we know how we can minimize this effect by appropriate use short ground.
In my opinion the company should choose the change of these components with some discount to anyone who wishes, without any problem to warranty.
Personal, I am not to dilemma. I'll apply the idea of solution of rf-loop in combination with added inside ferrites and I'll left behind me the politics of each company.
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In my opinion the company should choose the change of these components with some discount to anyone who wishes, without any problem to warranty.
This is minimum what I hope Owon do.
All manufacturers make mistakes. Leader is who learn from mistakes and also who give real support for customers in case of mistake.
If manufacturer do right things after some mistakes, these kind of things can, in best case, turn to win-win. But here we meet also cultural differencies.
Years ago I remember one case where manufacturer want more good reputation. They make designed (harmless) mistake and then show "look how good we are", fast solve problem and give full support for customers. After then customers talk "oh look how good and reliable manufacturer this is... " and result was all good for this manufacturer. Also some of these "hidden possibilities to hack" who can really think they are not designed...
Owon make they own decisions how they handle this kind of cases. World is open... they can free select bad or clever way to do.
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Personal, I am not to dilemma. I'll apply the idea of solution of rf-loop in combination with added inside ferrites and I'll left behind me the politics of each company.
This seems to be the only course of action left for those of us that would like to have better performance when working with low level signals at full bandwidth. It's a pity, because as far as specs and hardware, Owon could be a shinning star among competitors. If only they would live up to the standards that they have set for themselves in their motto. But it is their decision if they wish to remain in the crowded market of mediocrity.
As far as to the recent comments about rf-loop/aghp, personally, I've read every one of his posts, and in good faith, I can't characterize any one of them as propaganda for his own gain as an Owon dealer. Instead, I'm grateful for the well researched technical insight and well documented tests that he has contributed.
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Agree with TomC, and support Owon to take the best course of action for the interest of herself+customers.
Because of the honesty and expertise of RfLoop, AgHP (if one reads all along and not only abit here and abit there) -- would be cool to see what you look like actually :)
I am still looking forward to buy one as a beginner with moderate budget, but delaying until I have a hint that I'm getting the best possible version of the 7102;
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I was so set on one but suddenly I see myself erring toward a slightly more expensive Instek. Ahhh why must so many scopes be quite good. If only Owon made the menu system as good as Rigol's and fixed the noise I would jump on this thing even if it was a bit more expensive.
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Problem in new FW and LAN
I get answer from Owon about new LAN problem.
They have regognized problem and repair is coming soon. (Estimate: inside 2 weeks.)
I just got around to testing the latest patch (3.3) that was supposed to address this problem. It seems they fixed the High Memory depth option which works correctly via LAN on my scope now. However, the Image option still exhibits the same problem I had before via LAN. Everything works correctly via USB which is what I'm exclusively using for now. But this may be of interest for those that wish to use the LAN option.
There is also a new version of the oscilloscope software, but I couldn't find any improved or additional functionality other than it is supposed to support Windows 8.
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...
There is also a new version of the oscilloscope software, but I couldn't find any improved or additional functionality other than it is supposed to support Windows 8.
You mean the pc software 2.0.8.15 probably.
From what I have saw, they fix a problem with image (bmp) transfer to pc (test in windows XP) that was empty at 2.0.8.13 version.
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You mean the pc software 2.0.8.15 probably.
From what I have saw, they fix a problem with image (bmp) transfer to pc (test in windows XP) that was empty at 2.0.8.13 version.
I'm curious, are you using the 3.3 patch?
If so, does the image (bmp) transfer work via LAN?
I'm using Windows 7 and image transfer via LAN hasn't worked since the 3.2 patch. The 3.3 patch was supposed to fix this but it didn't for me. The 2.0.8.15 software didn't help either. Of course, everything works fine via USB regardless of the patch version (3.2 or 3.3), or software release (2.0.8.13 or 2.0.8.15).
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Just a stupid question, but are you sure that you're using the 3.3 patch? The 3.3 .exe file available on Owon's site has same hash as the original 3.2 version of the firmware.
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Just a stupid question, but are you sure that you're using the 3.3 patch? The 3.3 .exe file available on Owon's site has same hash as the original 3.2 version of the firmware.
I'm not sure how the hash turned out to be the same, but there is a difference in the functionality of the two files. The deep memory transfer via LAN works with the 3.3 patch (from the Owon site), but it doesn't work with the 3.2 patch.
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You mean the pc software 2.0.8.15 probably.
From what I have saw, they fix a problem with image (bmp) transfer to pc (test in windows XP) that was empty at 2.0.8.13 version.
I'm curious, are you using the 3.3 patch?
If so, does the image (bmp) transfer work via LAN?
I'm using Windows 7 and image transfer via LAN hasn't worked since the 3.2 patch. The 3.3 patch was supposed to fix this but it didn't for me. The 2.0.8.15 software didn't help either. Of course, everything works fine via USB regardless of the patch version (3.2 or 3.3), or software release (2.0.8.13 or 2.0.8.15).
Yes, I am using the 3.3 patch.
At the 2.0.8.13 I have saw a transfer image problem to pc. The previous versions haven't this problem. At the last (2.0.8.15) this problem has resolved. I didn't test via LAN but only with usb cable under windows XP (32bit).
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Yes, I am using the 3.3 patch.
At the 2.0.8.13 I have saw a transfer image problem to pc. The previous versions haven't this problem. At the last (2.0.8.15) this problem has resolved. I didn't test via LAN but only with usb cable under windows XP (32bit).
Thanks for the clarification, I wasn't expecting these differences in functionality depending on the Windows OS version. All of my computers use Windows 7 (64 bit). So I'll be sure to specify that in future posts.
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Just a stupid question, but are you sure that you're using the 3.3 patch? The 3.3 .exe file available on Owon's site has same hash as the original 3.2 version of the firmware.
Asked owon about that some time ago:
For space limited we save all the upgrade program together in one zip file together.
And the upgrade software will upgrade AUTOMATICALLY refer to specific version number.
Sorry for the confusion.
Best regards
Melissa Zhang
******************************************
Fujian Lilliput Optoelectronics Technology Co.Ltd.
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I'm aware that they pack multiple versions of firmware in same file (for example I used the "3.3" patch to update my SDS71021209xxx scope to firmware version 2.8.1.6), but that's not the answer here.
What I'm saying is that back when I downloaded the 3.2 patch, it had creation date of 2013-03-28 at 09:52 and size of 131.763.366 bytes. That file was downloaded back when 3.2 was the newest firmware. After that, 3.3 update appeared on the Owon site (and by Owon site, I mean owon.com.hk). I downloaded it (after some trouble, since they apparently never heard of character encoding on a HTML page, but that seems to be fixed now) and the file also had creation date of 2013-03-28 at 09:52 and size of 131.763.366 bytes. That looked strange to me, so I did MD5 hash of both files and got same result of ACBEBCF1B37A9B69DCDEE07EE6860837.
So that means that the 3.2 and 3.3 update files are completely same! Looking at the affected serial numbers, the only difference I can see is that the 3.2 patch has updates for SDS71021209xxx scopes, while 3.3 does not. For other scopes, it's the same. Publishing another 3.3 patch file gives impression to the users of non SDS71021209xxx scopes that there is in fact some change since the version 3.2, but in fact there is none, since they got the 3.3 in the first place.
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I haven't been reading this thread, but FYI I'm uploading a video of the SDS scope now. It's a seriously crappy scope! :--
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Ah, I should have read checked this thread before I did the video. I thought the SDS was a fairly new model, but apparently is 2 years old :-[
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I haven't been reading this thread, but FYI I'm uploading a video of the SDS scope now. It's a seriously crappy scope! :--
Ah, I should have read checked this thread before I did the video. I thought the SDS was a fairly new model, but apparently is 2 years old :-[
That's okay - always interesting to see what things you look at and what your comments are, and it'll be fun to watch even if it is about an "old" scope. Besides, 2 years is not so old for test equipment - even if a few interesting, even "game-changing" models have been released since then.
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Ah, I should have read checked this thread before I did the video. I thought the SDS was a fairly new model, but apparently is 2 years old :-[
Yes, the battery and VGA output (in a low-cost DSO) are it's main distinguishing points these days.
If you want to review a newer, low-end DSO that some members are clamoring about, you might look at the Uni-T UTD2102CM (https://www.eevblog.com/forum/testgear/uni-t-utd2102cm-waveform-capture-rate/), which, according to it's specs, does 150k wfrm/s (although they don't specify where and when it does that). Since it doesn't have intensity grading or a Trigger Out, it's been hard for people trying to figure out if it actually achieves those speeds.
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If you want to review a newer, low-end DSO that some members are clamoring about, you might look at the Uni-T UTD2102CM (https://www.eevblog.com/forum/testgear/uni-t-utd2102cm-waveform-capture-rate/), which, according to it's specs, does 150k wfrm/s (although they don't specify where and when it does that). Since it doesn't have intensity grading or a Trigger Out, it's been hard for people trying to figure out if it actually achieves those speeds.
I have a Tekway scope and will probably do a video on that on Monday.
http://www.triosmartcal.com.au/1961-tekway-dst1102b-digital-oscilloscope-with-wide-screen-hd-display.html (http://www.triosmartcal.com.au/1961-tekway-dst1102b-digital-oscilloscope-with-wide-screen-hd-display.html)
The Owon has a crappy 35wfm/s, or that's the best I could get out of it. And even that drops when you turn the menu on!
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The Owon has a crappy 35wfm/s, or that's the best I could get out of it. And even that drops when you turn the menu on!
Yes, it seems as if they're just acquiring the full 10MPts (10ms @ 1GSa/s) all of the time - and just displaying a smaller subset of that when the sample length is set to a smaller amount (but not changing the acquisition length).
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I have a Tekway scope and will probably do a video on that on Monday.
http://www.triosmartcal.com.au/1961-tekway-dst1102b-digital-oscilloscope-with-wide-screen-hd-display.html (http://www.triosmartcal.com.au/1961-tekway-dst1102b-digital-oscilloscope-with-wide-screen-hd-display.html)
The Owon has a crappy 35wfm/s, or that's the best I could get out of it. And even that drops when you turn the menu on!
This have discussed many times that this is not DPO, it is DSO.
But this using marmad method with two pulse it also can trig faster and capture but not continuously. (this is measured and result is in this other topic.
Table is here
(http://img163.imageshack.us/img163/7417/owontst1k10mtrig.png)
If you have Owon SDS and Tekway (Hantek) DST1000B (Hantek 5000B)
Turn it to 1M maximum memory.
Turn Owon to 1M memory.
Just look TFT and how it update. Which one you can calculate waveform update rate by own eyes.
(exept if Tekway/Hnatek have radically changed after I have tested it)
In many cheapest "entry level" oscilloscopes manufacturers claimed waveform update rates are just perhaps dreams.
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I have a Tekway scope and will probably do a video on that on Monday.
http://www.triosmartcal.com.au/1961-tekway-dst1102b-digital-oscilloscope-with-wide-screen-hd-display.html (http://www.triosmartcal.com.au/1961-tekway-dst1102b-digital-oscilloscope-with-wide-screen-hd-display.html)
I think you'll make many members happy with a video about that DSO as well; since it's so well-documented and hacked (thanks to tinhead) - and it's one which many people consider when looking for a low-cost DSO. But you do realize that it's about +3 years old as well, right? :)
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Ah, I should have read checked this thread before I did the video. I thought the SDS was a fairly new model, but apparently is 2 years old :-[
David, do you remember what fw version has it?
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I haven't been reading this thread, but FYI I'm uploading a video of the SDS scope now. It's a seriously crappy scope! :--
I wanted to buy this scope... But I did not. :) :)
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...but FYI I'm uploading a video of the SDS scope now.
I guess Dave went to sleep before his video finished uploading ;D
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Publishing another 3.3 patch file gives impression to the users of non SDS71021209xxx scopes that there is in fact some change since the version 3.2, but in fact there is none, since they got the 3.3 in the first place.
How do you account for the fact that there is definitely a change in functionality? Unless for some reason, applying the same patch twice changed things somehow. Maybe that's not too far fetched since the firmware is so flaky. With the 3.2 patch my scope would hang up every time I did a deep memory transfer via LAN, and the transfer would not complete. That stopped as soon as I applied the 3.3 patch.
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I have a Tekway scope and will probably do a video on that on Monday.
http://www.triosmartcal.com.au/1961-tekway-dst1102b-digital-oscilloscope-with-wide-screen-hd-display.html (http://www.triosmartcal.com.au/1961-tekway-dst1102b-digital-oscilloscope-with-wide-screen-hd-display.html)
oh jesus .. Dave, i'm sure you will not like it, it is very TEK like design (enclosure, menu and even "going slower when features
enabled" bug ^^). I will send you in a minute some topics what might be not visible directly (bad and good things) for you.
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I guess Dave went to sleep before his video finished uploading ;D
I think I have reloaded the main page well over 20 times now.... ^-^
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Publishing another 3.3 patch file gives impression to the users of non SDS71021209xxx scopes that there is in fact some change since the version 3.2, but in fact there is none, since they got the 3.3 in the first place.
How do you account for the fact that there is definitely a change in functionality? Unless for some reason, applying the same patch twice changed things somehow. Maybe that's not too far fetched since the firmware is so flaky. With the 3.2 patch my scope would hang up every time I did a deep memory transfer via LAN, and the transfer would not complete. That stopped as soon as I applied the 3.3 patch.
I'm quite sure that the explanation you provided is correct. Back when I had SDS71021211xxx main board in my scope, it would from time to time freeze during power-up. Reinstalling exact same version of firmware was one of Owon's solutions to the issue and it did have an effect; the rate at which used to freeze dropped quite significantly.
Do you still have the original 3.2 firmware file? If so, try comparing them yourself and post results.
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If you want to review a newer, low-end DSO that some members are clamoring about, you might look at the Uni-T UTD2102CM (https://www.eevblog.com/forum/testgear/uni-t-utd2102cm-waveform-capture-rate/), which, according to it's specs, does 150k wfrm/s (although they don't specify where and when it does that). Since it doesn't have intensity grading or a Trigger Out, it's been hard for people trying to figure out if it actually achieves those speeds.
I have a Tekway scope and will probably do a video on that on Monday.
http://www.triosmartcal.com.au/1961-tekway-dst1102b-digital-oscilloscope-with-wide-screen-hd-display.html (http://www.triosmartcal.com.au/1961-tekway-dst1102b-digital-oscilloscope-with-wide-screen-hd-display.html)
The Owon has a crappy 35wfm/s, or that's the best I could get out of it. And even that drops when you turn the menu on!
Can someone list some of the benefits of a 150wfm/s refresh versus a 35wfm/s refresh. All I can think of is that the DSO with the higher refresh rate would have a better chance of catching a transient, but it still may miss it for a long time or all together. So in the end it seems that either DSO would be the wrong instrument for the job. Unless it is possible to trigger on the transient, in which case either DSO should do.
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If you want to review a newer, low-end DSO that some members are clamoring about, you might look at the Uni-T UTD2102CM (https://www.eevblog.com/forum/testgear/uni-t-utd2102cm-waveform-capture-rate/), which, according to it's specs, does 150k wfrm/s (although they don't specify where and when it does that). Since it doesn't have intensity grading or a Trigger Out, it's been hard for people trying to figure out if it actually achieves those speeds.
I have a Tekway scope and will probably do a video on that on Monday.
http://www.triosmartcal.com.au/1961-tekway-dst1102b-digital-oscilloscope-with-wide-screen-hd-display.html (http://www.triosmartcal.com.au/1961-tekway-dst1102b-digital-oscilloscope-with-wide-screen-hd-display.html)
The Owon has a crappy 35wfm/s, or that's the best I could get out of it. And even that drops when you turn the menu on!
Can someone list some of the benefits of a 150wfm/s refresh versus a 35wfm/s refresh. All I can think of is that the DSO with the higher refresh rate would have a better chance of catching a transient, but it still may miss it for a long time or all together. So in the end it seems that either DSO would be the wrong instrument for the job. Unless it is possible to trigger on the transient, in which case either DSO should do.
It's not just about transients, but also giving a more comprehensive view of what is actually happenning, as you get with an analogue scope. With low update rate all you are seeing is an occasional snapshot - which is fine for repetitive signals, but much less useful if you are looking for changes or things that happen less often.
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Do you still have the original 3.2 firmware file? If so, try comparing them yourself and post results.
Yes, I checked the properties on both files and they are identical. I also used Windows File Compare (fc /b [file1] [file2]) to do a binary comparison. This test gave me the message "FC: no differences encountered". The 3.3 file I had was downloaded on 4/4/2013, one day after it was released, so I downloaded the file again today in case Owon had changed it since then. Again, the properties and the File Compare indicated that the newly downloaded file is identical to the older versions in my possession. One thing I noticed is that they changed the name of the RAR file to "SDS_Upgrade3.2and3.3.rar", however, the executable is still named "SDS_Upgrade3.2.exe".
Faced with these results, I decided to run the Patch again, hoping that it would fix the problem with image transfer via LAN, but no luck. For good measure I ran the patch one more time, again no luck. After testing deep memory transfer via LAN more thoroughly, I discovered some instances where it still causes the scope to freeze up. And even when it works it doesn't transfer as much data as when you use the USB interface.
In summary, the LAN interface only works properly for Waveform transfer. That makes it pretty useless for my purposes, so I'll have to stick to the USB interface. I had envisioned using the LAN interface to control the 7102 wirelessly from a Laptop, but even if they fix these problems there is still the issue of speed. It is extremely slow compared to the USB interface.
If anyone else is having better success with the LAN interface, I would surely like to know how you are doing it.
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I have a Tekway scope and will probably do a video on that on Monday.
http://www.triosmartcal.com.au/1961-tekway-dst1102b-digital-oscilloscope-with-wide-screen-hd-display.html (http://www.triosmartcal.com.au/1961-tekway-dst1102b-digital-oscilloscope-with-wide-screen-hd-display.html)
I think you'll make many members happy with a video about that DSO as well; since it's so well-documented and hacked (thanks to tinhead) - and it's one which many people consider when looking for a low-cost DSO. But you do realize that it's about +3 years old as well, right? :)
yeah, Tekways design is from Dec 2009, on the other side there are these new "P" models with only 24kpoint memory,
they do have faster SoC/memory - but the firmware and look&feel (fw and enclosure) remains the same (i got special
version, compiled for old hardware to allow me testing, so i know that there is no difference in fw), so review of whatever
model is in principle good for all of them, even for Hantek/Extech Handhelds (as they based on same hw).
Sure, doing review on 24kpoint DSO would not show the crap slowish menu when 1M/2M enabled, so it is good that Dave
have the model with 1M (that will be pure fun, "what? what's that?).
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At least the record length affects the waveform update rate. At Owon it doesn't.
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Daves review says a lot about the original review for this thread (CRAP :--). That is the review by the way. Otherwise this thread would have died ages ago along with the scope.
Just to say there are some pretty useless reviewers out there. :--
A retraction is posted.
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Daves review says a lot about the original review for this thread (CRAP :--). That is the review by the way. Otherwise this thread would have died ages ago along with the scope.
Just to say there are some pretty useless reviewers out there. :--
As the original reviewer all I can say is, you've clearly never watched the full review (which was made almost 2 years ago) - or read anything I wrote about the DSO. Almost every point Dave raised were issues I also had with the scope (UI, speed, etc) - especially the waveform update rate,which I measure in the video to show how slow it is - and explain why I'm RETURNING the DSO (which I had for about 4 weeks)!
As someone who actively and regularly contributes content to this community in an effort to be helpful to other people - and having looked through your long history of posting - I think I've leave it to others here to decide, between you and me, who is useless.
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Daves review says a lot about the original review for this thread (CRAP :--).
As the original reviewer. Almost every point Dave raised were issues I also had with the scope (UI, speed, etc) - especially the waveform update rate,which I measure in the video to show how slow it is - and explain why I'm RETURNING the DSO (which I had for about 4 weeks)!
As I watched Dave's review , I knew he had seen Marmad's review and was repeating every point, well more the bad points, even down to the shitting feet and sliding.
And I am Extremely Greatful for Marmad's many reviews that lead me to the DSO I have today :). So good was the Info, I found the best buy sooner.
mswhin63 , go back to your hole, Whining
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Daves review says a lot about the original review for this thread (CRAP :--). That is the review by the way. Otherwise this thread would have died ages ago along with the scope.
Just to say there are some pretty useless reviewers out there. :--
I watched Marmad's review again and found it to be objective and informative. It corroborates what Dave discovered in his own review, almost to a point. Your comments are totally unfounded.
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As the original reviewer all I can say is, you've clearly never watched the full review (which was made almost 2 years ago) - or read anything I wrote about the DSO. Almost every point Dave raised were issues I also had with the scope (UI, speed, etc) - especially the waveform update rate,which I measure in the video to show how slow it is - and explain why I'm RETURNING the DSO (which I had for about 4 weeks)!
As someone who actively and regularly contributes content to this community in an effort to be helpful to other people - and having looked through your long history of posting - I think I've leave it to others here to decide, between you and me, who is useless.
The number of post have no relevance, I noticed most forum based experience on the number of posts so newcomers are not welcomed much. seems fairly typical of most forums that I have been involved in. My opinions are not because I have a short history here but a long technical history, 30 years in the electronics industry. I just found your review too fairy touched like you were holding back, there was no substance to it and is totally unconvincing. Now it has taken 81 pages of really hard to follow information.A good post finishes quickly.
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The number of post have no relevance, I noticed most forum based experience on the number of posts so newcomers are not welcomed much. seems fairly typical of most forums that I have been involved in. My opinions are not because I have a short history here but a long technical history, 30 years in the electronics industry. I just found your review too fairy touched like you were holding back, there was no substance to it and is totally unconvincing. Now it has taken 81 pages of really hard to follow information.A good post finishes quickly.
Again, if you actually watched the review you don't seem to have been paying attention, since I covered virtually every point which Dave made, but I did it almost 2 years ago, before the introduction of a new generation of more powerful, lower-cost DSOs. Also, the length of this thread is much more a testimony to the few good selling points of the Owon and the lack of alternatives in this price range over the last couple of years than anything to do with my review - since I basically told people I was disappointed in the DSO and returning it. So to me (and some others as well I think) your opinions seem unfounded.
Edit: BTW, what makes your post even more nonsensical is the fact that I know of at least a few people who think/thought I was unduly HARSH on the Owon DSO with my review.
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Daves review says a lot about the original review for this thread (CRAP :--). That is the review by the way. Otherwise this thread would have died ages ago along with the scope.
Just to say there are some pretty useless reviewers out there. :--
I watched both reviews, I found them to be similar and very informative. I bought an SDS7102 in spite of the first review, I like many things about it, some others not so much. The reviews help many of us evaluate a buying decision, but you also have to look at your specific needs. That doesn't make a reviewer useless, I think both Marmad and Dave covered the main points very well, and expressed their honest opinion. To me that's what forums are all about, a place to exchange ideas and opinions. Personal attacks just sour the mood and tone of a good discussion, we can all learn from each other, and express disagreement without the need to put down others.
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I have a few comments on Dave's review. I’ll mention up front that I own the 100MHz version of this scope and, overall, I like it.
I fully agree with Dave’s implication that you’re throwing away your money if you spend $1,500 on an OWON SDS9302, BUT - dismissing the entire SDS line because of that is a mistake. Buying that model is like purchasing a Ford sedan with every option imaginable: You’ll wind up spending over $50,000 for a car built on a platform meant for a $30,000 model. Not a good decision when for $5,000-10,000 more you could have bought an equivalent Audi or BMW. However that doesn’t make the underlying model a piece of crap. It might be very competitive in its sweet spot of the low-to-mid thirties.
The ‘sweet spot’ of the SDS line is in the $300-500 range. If you spend $1,500 for a 9302 you get a $300 scope with 300MHz and 3.2 GS/s capability tacked onto it. Everything else is the same! The best things about the SDS line (the great screen and the huge memory depth) are tough to beat in an under $500 DSO – not so much in a $1,500 one.
Another thing about the model I own (the $429.00 SDS7102) is that it easily surpasses its stated 100MHz bandwidth - without hacks or alterations. Mine gets to over 150 MHz at the 3db down point and is functional to nearly 400MHz! Granted, the 1GS/s will limit its usefulness at those extreme limits but it’s very useable to over 200MHz.
The slow screen update seems to be the biggest complaint regarding the SDS line, and largely because of this Dave recommended the ancient Rigol 1000 series over the OWON SDS. From my point of view, there’s no way I would swap my SDS for the equivalent 1000 series model. The Rigol’s lack of dual vertical controls and limit of four measurements on that tiny low-res screen would annoy me far more than the slow screen update of the SDS. In the rare case when I’m looking for a glitch I use the persistence method that Dave demonstrated which ‘Works-a-Treat!’ (Sorry Dave).
Lastly, the scope hung when Dave attempted to save the screen to the USB card: That happens when the card is not formatted according to OWON’s specification (I know this from experience). Should the scope be so fussy about the formatting? – No, but cards are cheap and I keep one exclusively for use with mine. No problems since.
The scope is far from perfect. The PC software is very basic, and much more could be done with the firmware, but if someone handed me $500 today and said "Come back with the best scope you can find", I’d probably wind up buying another SDS7102.
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100% agree with rstoer - well presented. Mine does EXACTLY what I need it to do, and I am mindful of the limitations.
For the price, I can pop as many as I want out in the field (none yet though) and the battery option / screen size means I'm not
wasting my life trying to setup / position waveforms as in the little hand-helds. It's PERFECT for me.
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The Daves review is not bad!
He focused to some disadvantage of scope like his know better!
I agree with the post of rstoer, too!
The purchase of SDS9302 is a waste of money.
The target money group of SDS Series is 400-500$ with 7102 scope.
We know all, that the plus of this scope isn't the wfps but the price, the large and crispy display, the amount of depth memory, the battery option and the easily over the 100MHz bandwidth without any hucking (almost 150-200MHz/-3dB).
For anyone, that main job with scope is glitch...the Owon SDS7102 isn't good choice. Ok there is a solution with a persistance function but it isn' a real solution it is a semi-solution!
The fw of Owon SDS is not ergonomical and some functions is missing (fine tuning for example). Instead the arrangement of buttons is quite ergonomic, for my taste.
The last one year, Owon should had improvement the firmware, like reviewers told!
They didn't! Or the development software department is not sufficient or is their choice to offer a product with a low level software (target group with low budget)
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As I watched Dave's review , I knew he had seen Marmad's review and was repeating every point, well more the bad points, even down to the shitting feet and sliding.
I hadn't seen Marmads review. Ok, I may have seen it two years ago when it was posted, but I don't really remember it (although maybe subconsciously?). And I wasn't repeating it point by point.
If there are similarities it's likely because there are basic things you check and play around with on scope, and the crap/annoying stuff is pretty obvious to anyone knowledgeable who plays with it.
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I fully agree with Dave’s implication that you’re throwing away your money if you spend $1,500 on an OWON SDS9302, BUT - dismissing the entire SDS line because of that is a mistake.
I'm dismissing it because it's a PITA to use, has many firmware issues and problems that I would not want in test instrument.
Note that I did say there is a case where this scope might be for you, as there is with almost every product.
The best things about the SDS line (the great screen and the huge memory depth) are tough to beat in an under $500 DSO – not so much in a $1,500 one.
Sure, if you value those features over a test instrument that is much more refined and dependable.
The slow screen update seems to be the biggest complaint regarding the SDS line, and largely because of this Dave recommended the ancient Rigol 1000 series over the OWON SDS.
Not just that, but many more reasons why it got the tumbs down and the Rigol has had a thumbs up for the last 5 years.
The Rigol is just a much more refined scope you can have confidence in.
Not to mention that it's cheaper.
IMO, while the Owon might fills a very narrow niche in the $500 price point, I'd argue that the Rigol 1000E at $350 is a better choice, and above that the Rigol 2000 beats the crap out of the Owon at the $800 price point.
i.e. what I trying to say is that most people would be wasting their money on the $500 price point.
The bang-per-buck of the $500 Owon is nothing compared to the bang-per-buck of the $800 Rigol 2000.
From my point of view, there’s no way I would swap my SDS for the equivalent 1000 series model. The Rigol’s lack of dual vertical controls and limit of four measurements on that tiny low-res screen would annoy me far more than the slow screen update of the SDS.
As always, YMMV.
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If there are similarities it's likely because there are basic things you check and play around with on scope, and the crap/annoying stuff is pretty obvious to anyone knowledgeable who plays with it.
Sure. You can't really miss the crappy UI - especially after it pops up the third floating menu (I wonder if that was tacked on later in development after they realized they weren't going to be able to get all their info in the two menus) . In fact many of the unergonomic choices jump right out at you - making you wonder if Owon did any independent testing of their design and FW.
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Yes the fw menus, is not right ergonomically and needs redesign from the beginning. Although with time, you learn the menus.
Owon must improve the fw with some basic functions that missing. For example fine tuning in Volts, the push button is there for this purpose!
The member marmad has suggest a method for wfps measurement, but the Owon hasn't the choice "both of" on pulse triggering. Today, I connected a Fluke45 multimeter via Trigger (P/F) output and measure the output frequency at different inputs frequencies (Fluke measures from 5Hz to 1MHz, very well).
I don't know what exactly is Trigger out of Owon but plays from 6-150Hz according to Acquire Position, Time position and dots or vertical display. If found an appropriate time, I'll prepare a presantation of these.
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The member marmad has suggest a method for wfps measurement, but the Owon hasn't the choice "both of" on pulse triggering.
"marmad" have kindly suggested also other method.
Result with this other method is in this thread message "Reply #1227 on: June 09, 2013, 06:13:08 AM »"
No need scroll back, here is agen this result table:
(http://img163.imageshack.us/img163/7417/owontst1k10mtrig.png)
After capture and display waveform Owon can trig agen and capture next waveform after 2.35ms and show this captured waveform also on the display. TFT update speed is of course more slower. (and Owon trig out what is not real trig out exept with very slow speeds, just as I have told, it can ring bell in rest room that scope have trigged if it was waiting state leaved in lab.
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Thanks for the reminder "rf-loop" but from what I read, you had two channel generator for this measurement.
Although Dave says that it is not a total review of this scope, I have done a comparison with SDS7102 at last fw.
Let us summarize what Dave's finding to this scope, minus and plus.
I am not native in english language, please be patient about this.
Minus signs
1) the unit interface with complex menus. Not ergonomical and function with many jumps between buttons. For me it is true, with a time you learn this but OK isn't ergonomically. -> True.
2) the unit glides easy if you push the upper buttons. Yes it is true and there is some solution if you add some elastic naterial at its shoes. -> True
3) there is some amount of dc offset -> False, it needs calibration
4) there is no any fine mode at Volts & Time Divisions ->True, it is basic fw function that missing
5) some amount of alias of curve at running or stopped mode at 10K depth of memory (Daves uses sine signal at 1MHz). I am not an expert but it is normal if the memory length is under 2 times from signal frequency. It needs some attention and knowledge from the user. True or False (depend).
6) you can't change the lenght of memory depth at stopped mode. -> True.
7) at the Time Menu you can't choice specific area, you can only choice the time window to zoom - False the Horizontal Position Button doing this.
8 ) there is a break at the copy function. Dave doesn't give us the information what he is done with menus (external copy or internal) or if he done format at the stick with FAT or NTFS System. It is uncommon, however. -> False
9) there is a low wave frame update rate in unit, almost 25-35fps in all depth memory sets. -> I am not expert of this. If you attach the trigger output to Ch2, yes it is true the maximun trigger frequency at Ch2 is 35Hz. But I don't know what is really the trigger output of Owon and if this is really wfps! -> True with caution!
10) some kind of glitching at Ch1, when pressed the menu of Ch2 -> False at SDS7102
Plus signs
1) Large, crispy with good resolution, well angle view of display
2) Thin unit and no heavy. Battery option
3) Good software information at screen, when the unit does a BW limit under 5mV.
4) Pushable all buttons.
5) The way of trigger presentation at screen for both channels (like alternative trigger position).
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Hi Lemon,
Nice touch, just some points worth of note, I would say i have the latest version scope, not entirely sure but in the Minus section
1) The menus are complex but after a short time they are relatively easy to use. I can see the reason for the display layout but that will be user preference and possibly the designer. Marmad point this out that while the menus are up the centre of the screen is not impeded. So this is more user define issue, but I don't find it a fail at least. I don't press many button all the time so the ergonomics can be an issue if you press lots of button all the time but I have to agree there need to be a bit more thought in some functions.
2) The unit no longer glides easily, I can now press any button on the scope with one finger and it won't slide either with the feet in or out. Fix It does though slightly lift up just before the buttons activate. Don't think that can be fixed without more weight.
3) DC Offset calibration was mentioned in the review and a retraction made I think.
From this point i have only ever used an analogue scope. This is sort why i needed a lot of reviews and information to decide.
I think it is a good scope for it's price $469.00 including delivery I don't think I will "bork" at it. I an't afford a more expensive one at this time so I will make do. Would make a good portable though.
"bork" (Aussie slang don't know how to spell it only know how to say it)
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Thanks for the reminder "rf-loop" but from what I read, you had two channel generator for this measurement.
Yes. But one signal to oscilloscope (CH1).
For sure regognize these pulses there need be some difference. Most easy in many cases is generate two pulse with different pulse wide. Of course diffeence may also be level or both or some other difference as example different rising speed etc. (I have used different wide and different voltage so it was more easy detect with eyes. (also without persistence where first pulse just fast blinks (TFT update period)).
Signal generator channel A give first pulse and channel B give second pulse after adjustable delay.
These two pulses go to passive combiner input ports and combiner output signal go to oscilloscope CH1. So oscilloscope see first pulse, say example 10ns wide pulse and after adjusted delay there come example 20ns wide pulse. On the oscilloscope screen there can now easy wath that both pulses are displayed starting same trigger position. Scope is waiting trigger. First pulse occurs and scope trig and scapture it and it can see on the display but just after delay, there come second pulse and it can agen trig to this pulse and it show also this second pulse on the display.
It means that scope can capture and show new waveform after this delay.
Delay need adjust from zero to value until scope can trig to this second pulse also. If time is very small it can see on the display just after first pulse. Then rise delay... second pulse is out from display... maybe still captured if stop scope and zoom/scroll it visible. If delay is more... it occurs in scope dead time and scope is "blind" for this pulse. If add more and more delay there come agen situation where scope is agen ready for trig and capture new waveform. Now this second pulse rising edge is just same position (trigger point) where was this first pulse. When add delay just this point when it start trig to this second pulse after first trigged to first pulse is this time in table.
I hope you can understand this finglish language.
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2) The unit no longer glides easily, I can now press any button on the scope with one finger and it won't slide either with the feet in or out.
Do you have version where backside feets have pieces of black rubber?
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@rf-loop = I understood your method by 90%, but my generator is one channel and I can't to try it.
@mswhin63 = You mean that your scope has double rubber at its feet or make with diy approach yours "rubber feet".
I am thinking to summarize the fw changes that we need and send them to Owon, like fine mode of Volts & Time Div., the capability to change the resolution of depth memory at stopped mode e.t.c
Can you submit your suggestions?
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If someone think "what rubber".
Time ago Owon made small changes to these back foots.
There is a small pits for rubber pieces so it is less slippery.
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If someone think "what rubber".
Time ago Owon made small changes to these back foots.
There is a small pits for rubber pieces so it is less slippery.
Yep that is correct, the same rubber feet as rf-loop
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5$ on ebay:
http://www.ebay.com/itm/1-pcs-Brushless-DC-Cooling-11-Blade-Fan-6010s-12V-60x60x10mm-2-Wires-/160896610367?pt=LH_DefaultDomain_0&hash=item25762f703f (http://www.ebay.com/itm/1-pcs-Brushless-DC-Cooling-11-Blade-Fan-6010s-12V-60x60x10mm-2-Wires-/160896610367?pt=LH_DefaultDomain_0&hash=item25762f703f)
I guess the following one would fit better: http://www.digikey.com/product-search/en?WT.z_header=search_go&lang=en&site=us&keywords=603-1406-ND&x=-1708&y=-51 (http://www.digikey.com/product-search/en?WT.z_header=search_go&lang=en&site=us&keywords=603-1406-ND&x=-1708&y=-51)
Its impeller is of the same shape as the impeller of the original FAN and its motor has slightly better specs with the same current consumption.
And, of course, Delta is much better than noname.
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Perhaps your HW is 7102 1143xxx ?
Do you have any start up problem or any problem during use. Only problem is led color or any other problem?
You tell that FAN speed also drop.
I have a similar case, model number Owon 7102 1246099
After a certain time the system begins to slow down and finally it doesn't respond at all. No knobs are working. The display shows the measured waveform. Sometimes it works for weeks w/o any problem, but sometimes it won't work at all for, only display is functioning.
I have purchased this unit brand new in 2013 february. The problem appeared first time during the initial test.
Do You have any idea what can cause this issue?
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The member marmad has suggest a method for wfps measurement, but the Owon hasn't the choice "both of" on pulse triggering.
"marmad" have kindly suggested also other method.
Result with this other method is in this thread message "Reply #1227 on: June 09, 2013, 06:13:08 AM »"
No need scroll back, here is agen this result table:
(http://img163.imageshack.us/img163/7417/owontst1k10mtrig.png)
After capture and display waveform Owon can trig agen and capture next waveform after 2.35ms and show this captured waveform also on the display. TFT update speed is of course more slower. (and Owon trig out what is not real trig out exept with very slow speeds, just as I have told, it can ring bell in rest room that scope have trigged if it was waiting state leaved in lab.
It took me a little while to understand exactly how this test works. Unfortunately, I don't have the appropriate signal generator to try it for myself. The table reflects that the refresh rate of the units you tested is far better than the 35 wfm/s reported by other members. To make sure I understand this correctly I'd like to restate the results shown on your table a little bit differently. Let me know if I got it wrong.
------------------------------------------------------------------------------------------------------------------------------------
Depending on the setting of the time base the screen refresh rate of the SDS7102 falls in the following ranges:
Acquire Length Screen Refresh Rate
----------------- -----------------------
1K 76.9 - 425.5 wfm/s
10K 65.8 - 404.9 wfm/s
100K 62.5 - 390.6 wfm/s
1M 40 - 288 wfm/s
10M 10.5 - 80 wfm/s
------------------------------------------------------------------------------------------------------------------------------------
If this interpretation is correct it should put to rest the notion that the SDS7102 refresh rate is subpar compared to other DSOs in its price range. Thanks for the excellent data. I'm sure it took quite a bit of time and effort to compile it.
Edit:
Yes, it is wrong.
My opinion is: With this double pulse method can not proof continuous waveform update speed.
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Depending on the setting of the time base the screen refresh rate of the SDS7102 falls in the following ranges:
Acquire Length Screen Refresh Rate
----------------- -----------------------
1K 76.9 - 425.5 wfm/s
10K 65.8 - 404.9 wfm/s
100K 62.5 - 390.6 wfm/s
1M 40 - 288 wfm/s
10M 10.5 - 80 wfm/s
------------------------------------------------------------------------------------------------------------------------------------
If this interpretation is correct it should put to rest the notion that the SDS7102 refresh rate is subpar compared to other DSOs in its price range. Thanks for the excellent data. I'm sure it took quite a bit of time and effort to compile it.
Tom - this is unverified data and don't think it's helpful to spread what amounts to (from all we know until now) misinformation. Whether or not the Owon can capture a single pair of waveforms (or a few in a row) in this amount of time is irrelevant: the Owon is a DSO that has a slow continuous waveform update rate - there is absolutely no doubt about that. Not only is it readily apparent when you use the device - it has been confirmed in many ways: from numerous glitch tests I ran almost two years ago - to Dave's simple glitch demonstration in his video - to email confirmation from Owon themselves.
The Trigger Out rates repeated over and over in this thread - and measured again by Dave in his video - ARE the waveform update rates of this DSO (or very close to them) - this is what Owon confirmed in writing a long time ago already. Please don't try to convince people that it's otherwise unless there is some definitive proof beyond this chart.
I have used the Rigol DS1052E, the Owon SDS7102, the Hantek DSO5062B, and now the Rigol DS2000. The Owon was absolutely, without a doubt, the slowest of all these by a significant margin.
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Depending on the setting of the time base the screen refresh rate of the SDS7102 falls in the following ranges:
Acquire Length Screen Refresh Rate
----------------- -----------------------
1K 76.9 - 425.5 wfm/s
10K 65.8 - 404.9 wfm/s
100K 62.5 - 390.6 wfm/s
1M 40 - 288 wfm/s
10M 10.5 - 80 wfm/s
------------------------------------------------------------------------------------------------------------------------------------
If this interpretation is correct it should put to rest the notion that the SDS7102 refresh rate is subpar compared to other DSOs in its price range. Thanks for the excellent data. I'm sure it took quite a bit of time and effort to compile it.
Tom - this is unverified data and don't think it's helpful to spread what amounts to (from all we know until now) misinformation. Whether or not the Owon can capture a single pair of waveforms (or a few in a row) in this amount of time is irrelevant: the Owon is a DSO that has a slow continuous waveform update rate - there is absolutely no doubt about that. Not only is it readily apparent when you use the device - it has been confirmed in many ways: from numerous glitch tests I ran almost two years ago - to Dave's simple glitch demonstration in his video - to email confirmation from Owon themselves.
The Trigger Out rates repeated over and over in this thread - and measured again by Dave in his video - ARE the waveform update rates of this DSO (or very close to them) - this is what Owon confirmed in writing a long time ago already. Please don't try to convince people that it's otherwise unless there is some definitive proof beyond this chart.
I have used the Rigol DS1052E, the Owon SDS7102, the Hantek DSO5062B, and now the Rigol DS2000. The Owon was absolutely, without a doubt, the slowest of all these by a significant margin.
Thanks for the reply and the rebuttal. As I stated, I'm unable to verify this chart. So if it looks like I'm trying to sway peoples opinions, it wasn't my intention. As a new member of this forum, I'm amazed at the number of knowledgeable people like yourself that contribute to its popularity. For this reason, I doubt that my post will be misconstrued as gospel and taken at face value.
I've been able to verify the Trigger Out rates using a second scope, and if this is a reliable method for determining the refresh rate, I can confirm that the refresh rates I detected agree with yours and Dave's findings. However, I'm sure you have read, that the reliability of this method has been put in question. So I'm looking forward to additional discussion, clarifications, and tests results. Perhaps something has changed since you tested this hardware 2 years ago. If that's the case, I surely would like to know. If the chart posted by rf-loop is misinformation, I would like to know that too!
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About wfps for Owon SDS7102.
Guys I'm not an expert, but If I connected the trigger output (P/F) of Owon to a multimeter like Fluke45 at Frequency Postition, can you tell me what really measures with that? Is this appropriate for wfps measures?
If it yes, then Owon measures from low 10Hz (10M) to 450Hz(1K).
Unfortunately, the Owon dosen't have the Trigger "Both of" (rising time) and the rf-loop method needs a signal generator with a double channels.
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Perhaps your HW is 7102 1143xxx ?
Do you have any start up problem or any problem during use. Only problem is led color or any other problem?
You tell that FAN speed also drop.
I have a similar case, model number Owon 7102 1246099
After a certain time the system begins to slow down and finally it doesn't respond at all. No knobs are working. The display shows the measured waveform. Sometimes it works for weeks w/o any problem, but sometimes it won't work at all for, only display is functioning.
I have purchased this unit brand new in 2013 february. The problem appeared first time during the initial test.
Do You have any idea what can cause this issue?
Contact with Owon technical support immediately!
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About wfps for Owon SDS7102.
Guys I'm not an expert, but If I connected the trigger output (P/F) of Owon to a multimeter like Fluke45 at Frequency Postition, can you tell me what really measures with that? Is this appropriate for wfps measures?
If it yes, then Owon measures from low 10Hz (10M) to 450Hz(1K).
And on what timebases do you measure these frequencies? If you'll recall, in Dave's video, he has a frequency counter hooked up to the Trigger Out, and he can never get it to read more than 35Hz - regardless of the sample length.
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However, I'm sure you have read, that the reliability of this method has been put in question.
If the trigger output function is in question, then, well, the scope is faulty. Because a trigger out function is supposed to be just that. An output pulse that precisely matches the scope trigger rate.
There could of course in theory be a difference between the waveform trigger rate and how it processes and displays that information (it can't be faster of course, but could be slower), but that would also be a failure of the scope architecture IMO.
-
Depending on the setting of the time base the screen refresh rate of the SDS7102 falls in the following ranges:
Acquire Length Screen Refresh Rate
----------------- -----------------------
1K 76.9 - 425.5 wfm/s
10K 65.8 - 404.9 wfm/s
100K 62.5 - 390.6 wfm/s
1M 40 - 288 wfm/s
10M 10.5 - 80 wfm/s
------------------------------------------------------------------------------------------------------------------------------------
If this interpretation is correct it should put to rest the notion that the SDS7102 refresh rate is subpar compared to other DSOs in its price range. Thanks for the excellent data. I'm sure it took quite a bit of time and effort to compile it.
Tom - this is unverified data and don't think it's helpful to spread what amounts to (from all we know until now) misinformation. Whether or not the Owon can capture a single pair of waveforms (or a few in a row) in this amount of time is irrelevant: the Owon is a DSO that has a slow continuous waveform update rate - there is absolutely no doubt about that. Not only is it readily apparent when you use the device - it has been confirmed in many ways: from numerous glitch tests I ran almost two years ago - to Dave's simple glitch demonstration in his video - to email confirmation from Owon themselves.
The Trigger Out rates repeated over and over in this thread - and measured again by Dave in his video - ARE the waveform update rates of this DSO (or very close to them) - this is what Owon confirmed in writing a long time ago already. Please don't try to convince people that it's otherwise unless there is some definitive proof beyond this chart.
I have used the Rigol DS1052E, the Owon SDS7102, the Hantek DSO5062B, and now the Rigol DS2000. The Owon was absolutely, without a doubt, the slowest of all these by a significant margin.
Thanks for the reply and the rebuttal. As I stated, I'm unable to verify this chart. So if it looks like I'm trying to sway peoples opinions, it wasn't my intention. As a new member of this forum, I'm amazed at the number of knowledgeable people like yourself that contribute to its popularity. For this reason, I doubt that my post will be misconstrued as gospel and taken at face value.
I've been able to verify the Trigger Out rates using a second scope, and if this is a reliable method for determining the refresh rate, I can confirm that the refresh rates I detected agree with yours and Dave's findings. However, I'm sure you have read, that the reliability of this method has been put in question. So I'm looking forward to additional discussion, clarifications, and tests results. Perhaps something has changed since you tested this hardware 2 years ago. If that's the case, I surely would like to know.
If the chart posted by rf-loop is misinformation, I would like to know that too!
It is really carefully checked and not only one time tested.
But, it need carefully note that there is not claim for continuous waveform capture rate!
Table is just true if follow exactly what there read but only it.
I hope someone have equipments and time to verify it so we can leave these "unverified" comments to garbage. I can say that many of tests on this whole forum are "unverified".
If someone live in Finland and want own eyes check these results, just welcome to check.
lemon: this is not rf-loop method. It is marmad published method.
Then comment for example Hantek.
If Hantek is selected 1M memory and Owon is selected 1M memory Owon is not only marginally faster. It is much faster. This is not opinion. This I know. But this is not so relevant here and it have discussed many times before.
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This is from a long email exchange I had with Owon in August of 2011 (they knew I was the 'marmad' who had posted the video review of the DSO). At that time, the highest frequency I could measure from Trigger Out was 25Hz (according to previous posts by rf-loop, they have increased this over the last 2 years to around 35Hz).
I wrote to Owon:
"The fastest speed I ever see on the Pass/Fail tests is about 18 times per second - which, in comparison, is about ½ the speed of the Rigol DS1052E – a cheaper and slower scope. I suppose my bigger worry is what the speed of these tests (and the Trigger Out) indicate about the waveform update rates and the ‘dead’ time (or ‘blind’ time) of the scope.
With Trigger Out, I always see output in the range of ~1 – 25Hz only, which would tend to indicate 1 – 25 waveforms per second – or a ‘blind’ time, for example, at 200ns/div, of 99.99%.
Can you please let me know if I am incorrect and the waveform update rate for the Owon SDS7102 is faster than this?"
Owon wrote to me:
"The waveform updated rate you mentioned is correct, unlike DS1052E (LCD display is 320*234), ours is 800*600 pixels, so there is more work for DSO to handle with, which result in updated rate is lower."
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But, it need carefully note that there is not claim for continuous waveform capture rate!
Which is exactly what I was referring to when I wrote "unverified": as continuous waveform capture rate. When Tom writes those data in the form of HZ, he's implying they are continuous.
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But, it need carefully note that there is not claim for continuous waveform capture rate!
Which is exactly what I was referring to when I wrote "unverified": as continuous waveform capture rate. When Tom writes those data in the form of HZ, he's implying they are continuous.
Yes, it is wrong.
My opinion is: With this double pulse method can not proof continuous waveform update speed.
But still result from Owon is markable becouse it tell that it can trig to random occurence before it can expect if use max continuous average waveform update rate for thinking. So, inside this some low average speed it can do momentarily also capture much faster. And this duble pulse method show this fastest possible retrig/capture period. There is not DPO memory for collect many of these over each others, there can be perhaps just one waveform waiting in sampling buffer for transfer to memory where from it displayed?
Also my old photograph method supports the idea that the average maximum is around 35wfrm/s. And perhaps I have now some explanation why in my old photograph method these waveforms traces on the screen have sometimes markable different spacing but in theory they need be nearly same spacing becouse signal sweep was linear. Becouse it can trig and capture faster. (but not continuously)
One old test image sample is here. (https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/msg92751/#msg92751)
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Yes, it is wrong.
My opinion is: With this double pulse method can not proof continuous waveform update speed.
But still result from Owon is markable becouse it tell that it can trig to random occurence before it can expect if use max continuous average waveform update rate for thinking. So, inside this some low average speed it can do momentarily also capture much faster. And this duble pulse method show this fastest possible retrig/capture period. There is not DPO memory for collect many of these over each others, there can be perhaps just one waveform waiting in sampling buffer for transfer to memory where from it displayed?
Also my old photograph method supports the idea that the average maximum is around 35wfrm/s. And perhaps I have now some explanation why in my old photograph method these waveforms traces on the screen have sometimes markable different spacing but in theory they need be nearly same spacing becouse signal sweep was linear. Becouse it can trig and capture faster. (but not continuously)
Agreed. We all know that the hardware in the Owon is good - and is likely 'held back' in ways by firmware architecture.
I just think firmware is not Owon's cup of tea. I wish they would realize that and make the decision to sell an 'open' version of the SDS with an SDK for coders and hackers to roll their own firmware. I think within 6-9 months, there would be really interesting (and faster) versions of firmware for it - and Owon would sell more of them then ever. But I guess this will never be the Chinese way.
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About wfps for Owon SDS7102.
Guys I'm not an expert, but If I connected the trigger output (P/F) of Owon to a multimeter like Fluke45 at Frequency Postition, can you tell me what really measures with that? Is this appropriate for wfps measures?
If it yes, then Owon measures from low 10Hz (10M) to 450Hz(1K).
And on what timebases do you measure these frequencies? If you'll recall, in Dave's video, he has a frequency counter hooked up to the Trigger Out, and he can never get it to read more than 35Hz - regardless of the sample length.
I got readings similar to Lemon's with a frequency counter, but apparently the signal is mixed with some low level noise and can fool some frequency counters into registering higher frequencies. Using a second scope to view this signal cleared this up for me, the duration of a cycle is never less than around 30ms. However the duty cycle varies quite a bit depending on the time base and acquire length settings on the Owon.
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About wfps for Owon SDS7102.
Guys I'm not an expert, but If I connected the trigger output (P/F) of Owon to a multimeter like Fluke45 at Frequency Postition, can you tell me what really measures with that? Is this appropriate for wfps measures?
If it yes, then Owon measures from low 10Hz (10M) to 450Hz(1K).
And on what timebases do you measure these frequencies? If you'll recall, in Dave's video, he has a frequency counter hooked up to the Trigger Out, and he can never get it to read more than 35Hz - regardless of the sample length.
Yeap "marmad" I have seen the measurement with the Agilent Frequency Counter that Daves presentated and for that reason I''ll tried to do same with my multimeter a Fluke45.
I don't want to prove something but it was my curiosity and for this reason I asked Daves what fw has the SDS9302.
My Owon is SDS7102V with 12118XX serial number and the last 3.3 patch fw.
I have try the following test in two Fluke45 multimeters (Frequency position, 5Hz-1MHz), this video is from the newer of them.
As I told many times, I don't speak the english language well and of cource in this video I don't try to speak!
At the begging of video I have attached the generator output (Hameg 10MHz function generator) to the Fluke and test the accuracy of frequency at three different frequencies, at the last I choosed the 0.98MHz (cause 1MHz limit of Fluke45) because Dave's test was with 1MHz frequency.
I zoomed between oscilloscope screen and fluke screen because my video isn't a HD. The video with Fluke and Owon at the same image isn't clearly! For that reason I prefered a zoomed area, now the interesting areas are clearly!
I started with Memory Depth of 1K, with almost all time range of oscilloscope and keep this method of presantation to the others 10K,100K, 1M (I jumped this), 10M. All the time the Fluke demonstates the frequency capture.
Initial the capture is for Ch1 (activate), Ch2 is deactivated. At the end, I activated both of them (measuring at 1K) because I saw that Frequency of Trigger Output is increased with both of them.
I know that Fluke45 isn't a Frequency counter but has a Frequency measurement function. If I connect the Trigger Output (TTL) of Hameg generator to Fluke45, it measures the frequency output of genarator (at my example 0.98MHz). But here what measures really the Fluke from Owon?
Owon SDS7102 wfps (?) (https://www.youtube.com/watch?v=JpVhUKTHor4#)
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But still result from Owon is markable becouse it tell that it can trig to random occurence before it can expect if use max continuous average waveform update rate for thinking. So, inside this some low average speed it can do momentarily also capture much faster. And this duble pulse method show this fastest possible retrig/capture period. There is not DPO memory for collect many of these over each others, there can be perhaps just one waveform waiting in sampling buffer for transfer to memory where from it displayed?
Also my old photograph method supports the idea that the average maximum is around 35wfrm/s. And perhaps I have now some explanation why in my old photograph method these waveforms traces on the screen have sometimes markable different spacing but in theory they need be nearly same spacing becouse signal sweep was linear. Becouse it can trig and capture faster. (but not continuously)
One old test image sample is here. (https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/msg92751/#msg92751)
So as I understand it now, within 1 sec, the Owon consistently triggers at least once, within a time period that is substantially shorter than its average or continuous screen refresh rate. However, the average/continuous refresh rate never exceeds about 35wfm/s. Again, let me know if I got it wrong!
If this is correct, it should be good news for those interested in catching glitches with this DSO. It seems it would increase the odds of the Owon catching a recurring glitch, even if its recurring rate is close to the Owon's continuous refresh rate. Still, my opinion is that it would be far better to use a DPO for this job.
(and Owon trig out what is not real trig out exept with very slow speeds, just as I have told, it can ring bell in rest room that scope have trigged if it was waiting state leaved in lab.
Would you care to clarify this comment. I tend to agree with Dave's comment that the Trig Out should be a true representation of the scope's trigger. Or do you have some inside information that this is not a real trigger out and thus using it to evaluate the scope's refresh rate will lead to erroneous conclusions?
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Hi Marmad,
I have to apologise for this post, instead of deleting it I have struck it through to display my anger at the time and with myself.
A couple of things haven't changed but one thing this thread is too long now and need to a fully updated. Mentioned this and reason why in the other thread, too long to repeat.
https://www.eevblog.com/forum/blog/eevblog-480-300mhz-owon-sds-oscilloscope/msg245986/#msg245986 (https://www.eevblog.com/forum/blog/eevblog-480-300mhz-owon-sds-oscilloscope/msg245986/#msg245986)
Cheers
Daves review says a lot about the original review for this thread (CRAP :--). That is the review by the way. Otherwise this thread would have died ages ago along with the scope.
Just to say there are some pretty useless reviewers out there. :--
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I know that Fluke45 isn't a Frequency counter but has a Frequency measurement function. If I connect the Trigger Output (TTL) of Hameg generator to Fluke45, it measures the frequency output of genarator (at my example 0.98MHz). But here what measures really the Fluke from Owon?
I think your meter is not capable of measuring the Trig Out of the Owon correctly because at the higher time base settings what comes out of the Owon is almost just plain 5VDC. The negative pulses can be as small as 2.5 microseconds, and the positive part about 30 milliseconds. Your meter is looking for a sine wave or something close to it, with a crest factor of less than 3. The TTL signal coming from your Hameg generator is closer to a square wave, which your Fluke 45 can measure correctly. If you look at the signal from the Owon's Trig Out with a scope, there is a low level noise riding on the positive part of it. I think your Fluke 45, which has a sensitivity in the millivolts range, is giving you the frequency of this low level noise signal since it is the only thing at its input that resembles a sine wave.
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TomC, your theory has a right base and gives a good answer to my question.
Thanks a lot for that. :-+
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I've been using my SDS7102 for nearly 5 months now. The purchase price was US $429 including the VGA, LAN, bag, and shipping. I've been using oscilloscopes professionally and for my own hobbies since I was a teen, but until recently my experience was limited to CROs. Now that I'm retired, I've been trying to upgrade my electronics lab with modern equipment while being budget conscious. I looked at many videos of different DSOs and read every review I could get my hands on before deciding to purchase the SDS7102. In retrospect, I still think that my decision was right for me, but I feel that all of my research failed to uncover some of the things that annoy me the most when using this DSO. At the same time, some of the things that were most fervently criticized by others, I've only found to be minor annoyances or just fine for my taste. So here is a list of the things that I currently like and dislike. It's just my opinion and based on my personal likes and dislikes. So feel free to jump in and challenge, criticize, or agree with any of it.
What I like:
1. The price.
2. The screen size and resolution.
3. The size, weight, stylish look, and thinness. I have 2 workbenches with pegboards and a top shelf. The top shelves hold most of my test equipment. For the DSO I was able to install a small shelf at eye level on each pegboard. This allows me to easily move it from one workbench to the other depending on what I'm doing. With this setup there is no possibility of sliding when you push any of the buttons.
4. The layout of the user controls and interface connectors. I find it uncluttered and logically grouped. The use of slightly different background shades highlights the different groups of controls thus making them easier to locate. The matching button and screen colors serves as a convenient reminder of the waveforms origin.
5. The fact that the scope is usable to around 200MHz without hacks or modifications.
6. The deep memory.
7. The VGA feature. I was an educator for a large computer company for 25 years. The use of overhead projectors for technical presentations was commonplace then. Now I can use this DSO to show actual live waveforms on a big screen TV. Granted, the only audience I have now is my wife. But it sure makes an impression when I pop up a waveform from my latest project while she's watching TV.
Minor Annoyances:
1. The GND noise. Yes, I can rethink my grounding arrangement whenever this issue gets in the way. But this gets kind of annoying if you are checking something simple, for example, the ripple of an analog PS.
2. The acronyms used to label some user settings on the screen, for example, M for time base.
3. The acronyms used for some of the measurements, for example, Vk for Vrms.
4. The menu system structure. Although after some time, I've become accustomed to it. Now I wonder if relearning to navigate a better organized menu system may also prove to be annoying at first.
5. The math function doesn't remember the last V/div setting used.
6. Can't turn off CH1/CH2 display while using the math function.
7. For regular use, the lack of a fine V/div & Sec/div adjustment. However, for XY mode, see Major Disappointments below, I find this to be more than a minor annoyance.
8. The slow screen refresh rate. For my current needs, mostly hobby related, I seldom find myself chasing glitches. So the refresh rate didn't have a lot of influence on my buying decision. However, the only other scopes I own are older Tek CROs, and although they are often useful for this type of thing, I no longer care for the use of visors or dark rooms just to catch a glimpse of phosphor radiation. So now I want, but don't really need, a DPO. Any ideas on how to convince a budget conscious wife that this is a good idea?
Major Disappointments:
1. The LAN interface. I have my electronics lab as well as the rest of the house wired through the walls for network access. The network includes several computers, televisions, WMC extenders and other entertainment equipment. When I purchased the scope I envisioned being able to monitor and control the scope from the lab while it was hooked up to equipment or gadgets in different locations throughout the house. But the LAN interface was crippled by slow speed from the beginning. With the latest firmware patches it has been further crippled by a non-functional image transfer, and a flaky high depth memory transfer that in certain cases causes the DSO to freeze.
2. The Remote Control Software. Even via the USB interface, which works reasonably well, using this feature is harder than playing the violin while somebody pulls clumps of hair off of your head. It doesn't read the current settings off of your scope, so if you change any setting, be prepared to see many other settings change to the default values used by the application. Sure you can change everything back to what you want, eventually, but it's more of a headache than a convenience.
3. The XY mode. I have a semiconductor curve tracer which has been permanently connected to a dedicated CRO for some time. I often salvage parts from discarded electronic equipment and this setup is useful for classifying as well as discovering the characteristic of unknown devices. When I purchased the Owon I envisioned hooking it up to the curve tracer to capture images of the characteristic curves of unknown devices. However, the curve tracer/scope calibration procedure calls for finely adjusting the scope's V/div on the X & Y channels until the correct pattern is displayed. That was never a problem with my CROs, but the Owon engineers decided to leave out the fine adjustment. So I'm unable to properly calibrate my brand new modern DSO for this task.
Even if I could live with a slightly uncalibrated display, there are more issues with the XY mode that are incredibly disappointing, at least for me. With the Owon's beautiful large screen, why would they limit the XY display to 6.5 x 6.5 graticules, leaving more than half of the screen's real state unused.
Then there is the fact, that you may not even get an xy image, unless you discover that the screen refresh rate and scope dead time has to be synchronized to your signal source. The manual states that the Time Base is not used for this mode, but changing the time base setting is the only method I found that allows you to vary the refresh rate until a trace is visible (See images captured using different time base settings). Notice that the trace consists of dots, making it fuzzy and unappealing, and you can't improve it's looks by turning on the persistence, because in XY mode the Persistence feature is non-functional.
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Thanks "TomC" for this reference.
I had propose ago, to summarize "what we want to has the next Owon fw'" and this list submited to Owon Info.
Please, add to the list and for those with native english language, correct the syntax and grammar of this list.
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*) There is a complex menu with a lot of jumps from one button to other. As nice is the ergnomic of buttons as ungly is the firmware (fw).
Example-1 : there is no cyclic function in most buttons, look at SDS Series User Manual at figure 5-19 “Edge Trigger Menu”. Each time you pressed the button H4 “slope” it changed with cycle sequence “Trigger on Rising Edge” and “Trigger on Falling Edge” and that is what customers need for all buttons. It isn’t ergonomical to jump to vertical menu to change this. It is more easy to change this, each time to press the button.
Example-2: Look at SDS Series User Manual at figure 5-4 “Regulation of the Attenuation Ratio of the Probe”. Why the attenuation table (X1, X10, X100, X1000) pop-up at the left of screen and not to the right side, next to Probe Table (Attenuate)?
Example-3: Look at SDS Series User Manual at figure 5-5 “Measure Current”. Why you must turn the M knob continues to jump to a higher value? It is more ergonomically, each time to press the M knob to change the hundreds, tens, units…it is more quick and simple!
At the end for the menu ergonomics, there are many customers that believe to must redesign the menu and add some function that missing. Some others believe that's better to offer you an open source firmware (free) for development from power users. It is something that going to improve the image of Owon company to all customers. But this is something that is yours decide.
*) There is no way for fine (adjust) mode at Volts & Time Divisions. The two buttons are push-able but pressing the buttons the fw does nothing.
*) You can't change the length of memory depth at stopped mode. If you stopped the running, all the other choices of memory length are cancelled with exception the last length of memory you had choice.
*) Fw doesn’t have split-screen modes (double window) for FFT, or the usual split-screen zooming in on waveforms.
*) No way to mark, searches easily, or jump through wave records: this is just a "pain" for a scope with records, which can be 10Mpts long.
*) You can’t the display on real time all the measurements, only static! It is important to have all the measurements at the top or at the bottom with some transparency. Now blocs the curve and it appears with an ugly static image!
*) At the Edge Trigger Menu, there are two choices with "Trigger in rise edge" and "Trigger on falling edge". Missing the third choices “Both of” rising and falling edges
*) No linear interpolation of points or you can't turn off sin(x).
*) Correct some errors like "Vp" ro "Vp-p" (Voltage Peak to Peak), “Vk” to “Vrms” (Voltage RMS) to the Measurement Section.
*) The math function doesn't remember the last V/div setting used.
*) The LAN interface was crippled by slow speed from the beginning. With the latest firmware patches it has been further crippled by a non-functional image transfer, and a flaky high depth memory transfer that in certain cases causes the DSO to freeze.
*) The Remote Control Software. Even via the USB interface, which works reasonably well, it doesn't read the current settings off of your scope, so if you change any setting, be prepared to see many other settings change to the default values used by the application. Sure you can change everything back to what you want, eventually, but it's more of a headache than a convenience.
*) The slow refresh rate of screen in the range of 20-35 wfps. With this wfps, it is difficult to catch some glitches of the input signal.
*) .... please TomC, describe the problem of X/Y without personal references.
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Please, add to the list and for those with native english language, correct the syntax and grammar of this list.
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*) .... please TomC, describe the problem of X/Y without personal references.
Lemon, I don't see anything difficult to understand on your list. The Chinese are not native speakers either. I wouldn't worry about syntax and grammar, just that the points you want to make get across.
As to the X/Y problem, maybe something like this will do:
On the X/Y mode 6.5 x 6.5 graticules is not sufficient, more of the screen should be used. The display should synchronize with the input signal independently of the time base setting, currently you may not get a display at all unless you find an appropriate time base setting. Also, a dot display is unappealing, you should be able to choose vectors or dots. In addition, the persistence feature should be enabled in case it's necessary to improve the way the signal looks.
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But I would wait a little bit on this, I only tested the X/Y mode with my curve tracer, maybe some other members will add comments on this now that the issue has been brought to light. Also, I don't know how well the X/Y mode works on other DSOs in the same price range, I've only used it with CROs in the past. Maybe we will get some comments about that too.
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TomC,
I liked your post. My list of likes and minor dislikes is similar to yours. I haven't found any major dislikes, probably because I don't use the features you like the least - the X-Y & LAN output (I don't even have the LAN jack but probably wouldn't use it anyway). I also seldom use the PC software.
One of these days I'm going to try Lemon's ferrite fix for reducing the induced switching (Gnd) noise. Being a 2011 model mine's not that bad, but it still has some. For a simple procedure it seemed to make a real difference. Did you ever think of trying it?
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TomC,
I liked your post. My list of likes and minor dislikes is similar to yours. I haven't found any major dislikes, probably because I don't use the features you like the least - the X-Y & LAN output (I don't even have the LAN jack but probably wouldn't use it anyway). I also seldom use the PC software.
One of these days I'm going to try Lemon's ferrite fix for reducing the induced switching (Gnd) noise. Being a 2011 model mine's not that bad, but it still has some. For a simple procedure it seemed to make a real difference. Did you ever think of trying it?
Yes, I would also like to try rf-loop's DIY, but that'll have to wait until the scope is a little older because it voids the Warranty. Another thought I had is to use a ferrite based absorption material that you can stick to the circuit board. I saw this mentioned on a technical article someplace, but now that I think I have an application for it, I'm having a hard time finding where I filed it.
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Another thought I had is to use a ferrite based absorption material that you can stick to the circuit board. I saw this mentioned on a technical article someplace, but now that I think I have an application for it, I'm having a hard time finding where I filed it.
I finally found the article where I read about this. The variety on the attachment seems to have a frequency range that may be effective for the SDS7102 GND noise. Has any one experimented or used these type of materials, if so, would you mind posting your impression, results? The FFAM06 sheets are the least expensive I found so far, about US $10 for a 4" x 4" at Digi-key.
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Looking at that I would try just using a few pieces of flat magnet, as it is basically the same, lossy ferrite in a flexible binder. Comes as strips in a fridge door, or for free as magnetic decals, and is self adhesive onto ferrous substrates.
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Looking at that I would try just using a few pieces of flat magnet, as it is basically the same, lossy ferrite in a flexible binder. Comes as strips in a fridge door, or for free as magnetic decals, and is self adhesive onto ferrous substrates.
I have tried the magnetic decals, the type you get in the mail advertising phone numbers of dentists etc., but not for this particular application. When I tried to use them as a substitute for ferrite cores by rapping them around wires, etc. the effect was very minimal compared to a real ferrite core. Probably the grade of the magnetic material has to do a lot with their efficacy. I'm with you that the price for a 4" x 4" seems kind of high, so I'm hoping that someone that has used them will shed some light on whether they are worth that price.
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Looking at that I would try just using a few pieces of flat magnet, as it is basically the same, lossy ferrite in a flexible binder. Comes as strips in a fridge door, or for free as magnetic decals, and is self adhesive onto ferrous substrates.
Be careful with magnets. They may saturate inductor cores. Thus, if the best happened, noise will increase dramatically. In some cases a converter IC may burn down if its overcurrent protection circuit is not good enough.
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Looking at that I would try just using a few pieces of flat magnet, as it is basically the same, lossy ferrite in a flexible binder. Comes as strips in a fridge door, or for free as magnetic decals, and is self adhesive onto ferrous substrates.
Be careful with magnets. They may saturate inductor cores. Thus, if the best happened, noise will increase dramatically. In some cases a converter IC may burn down if its overcurrent protection circuit is not good enough.
EU1, do you have any experience with ferrite based absorption materials similar to the one I posted on the previous page? I have read that they work very well, but all the information I have comes from the manufacturers, so it's probably at least somewhat biased. I would like to have some independent confirmation of their worth or worthlessness before I try them.
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Be careful with magnets. They may saturate inductor cores. Thus, if the best happened, noise will increase dramatically. In some cases a converter IC may burn down if its overcurrent protection circuit is not good enough.
EU1, do you have any experience with ferrite based absorption materials similar to the one I posted on the previous page? I have read that they work very well, but all the information I have comes from the manufacturers, so it's probably at least somewhat biased. I would like to have some independent confirmation of their worth or worthlessness before I try them.
Absorption material should not be magnetic as will change it ferrite properties to absorb the radiation. Fridge magnets are permanently magnetised and so CAN not necessarily will saturate an inductors core and alter the effectiveness of the inductor properties. Ferrite based protection shield are always non magnetic.
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EU1, do you have any experience with ferrite based absorption materials similar to the one I posted on the previous page?
I have not used it, but I guess a simple tinplate shield would be effective enough.
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What I'm looking for is a way to eliminate or dramatically reduce the SDS7102 GND noise without altering the circuit boards in any way. Several other approaches have already been offered, but they all have the potential of voiding the manufacturer's Warranty. That's something I'm not willing to do at this time, and I think this is also the position of some of the other members that own SDS7102s.
So I'm looking for a solution that only involves modifications that can be easily removed if the scope has to be sent to the manufacturer for under Warranty repairs. That includes Snap-On ferrite cores, which have been used successfully by other members to filter out some of the noise.
What I'm trying to get input on, is the possibility of using this ferrite based absorption material in combination with ferrite cores to get results similar to what rf-loop obtained with his DIY modification. I don't advocate in any way using magnets, and I think the warnings posted by other members about magnetic core saturation should be heeded. Using tin shields or faraday shields has also already been brought up and tried by some members, but this approach usually involves soldering or other modifications that are not so easily undone trace free.
So I'm hoping that some of you may have experience with this ferrite absorption material that you want to share, or other suggestions that don't involve circuit board alterations. The main criteria is that it's something that can be easily undone trace free.
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Why not use conductive paint inside the box to shielding it?
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Why not use conductive paint inside the box to shielding it?
Thanks for the tip, I'm investigating some sources of that stuff now that you brought it up. Only downside I see so far is removing it if the scope has to be sent in for under Warranty repairs.
Edit: From my limited research, it seems that there is a wide variety of these products available. However, it seems that the ones economically feasible for this project are carbon based, and therefore resistive and with poor shielding characteristics. The plus side is that they are water soluble and apparently easily removed with soap and water. So they may be useful for a wide variety of other applications. I'll look some more as I have time, there may be something in this category that may be helpful to partly address the GND noise issue. For now, I'm still looking for further ideas and any other information on the ferrite based absorption materials.
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At the post #1197 I done a test with a metal cage (not entirely closed) to psu board. It was open to ac side and close to adapter board side.
This eliminated the EMI and decreased the noise by 0.5 (X)
The same was happening with a large cylindrical ferrite to the cable btw the two pcbs.
If you make an internal shield to all plastic cage of oscilloscope, will be a shield to outside environment but not to inside.
I am not an expert but my opinion is that there is three solutions about these:
1) Cancel of noise with a lot of decoupling capacitors to specific areas of psu and adapter boards (rf-loop method)
2) Filtering the emi with appropriate ferrites to some cables and probes.
3) A metal cage for the psu board (very difficult, small and strange area).
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At the post #1197 I was done a test with a metal cage (not entirely closed) to psu board. It was open to ac side and close to adapter board side.
This eliminated the EMI and decrease the noise by 0.5 (X)
The same was happening with a large cylindrical ferrite to the cable btw the two pcbs.
If you make an internal shield to all plastic cage of oscilloscope, will be a shield to outside environment but not to inside.
I am not an expert but my opinion is that there is three solutions about these:
1) Cancel of noise with a lot of decoupling capacitors to specific areas of psu and adapter boards (rf-loop method)
2) Filtering the emi with appropriate ferrites to some cables and probes.
3) A metal cage for the psu board (very difficult, small and strange area).
I agree that metallizing the scope's cabinet would not help the noise in the inside. So I'm not looking at this approach as even a partial solution right now. However, I think that there may be other opportunities where shielding may be beneficial inside the scope. In that area I'm looking for ways to implement it that are easier than trying to construct a rigid faraday cage as you did. For example, pressure sensitive metallized tapes. It is in this area, where I thought some types of conductive paint may also be helpful, for example, to complete an electrical connection of the shield to a ground trace without soldering. I'm also looking at transparent shielding materials that may be useful to reduce the EMI radiating from the TFT panel. Then there is the ferrite based absorption material that I've been talking about. Here I'm hopeful that this would be effective in reducing the EMI emanating from components and circuit traces by applying it directly to them, or in one of the other configurations advertised by the manufacturers. Also, there is the proven line of defense, as you documented on your post, a ferrite core on the ribbon cable between the PCBs.
So in summary, what I'm envisioning is a multi-pronged approach including some of the already proven techniques and adding some others that haven't been explored yet. At this point I'm just gathering information, here are some links to some of the information I've been looking at, let me know what you think. The same goes for any other members that are interested, your ideas and comments are always welcome.
http://multimedia.3m.com/mws/mediawebserver?mwsId=66666UuZjcFSLXTtnxTynXfEEVuQEcuZgVs6EVs6E666666-- (http://multimedia.3m.com/mws/mediawebserver?mwsId=66666UuZjcFSLXTtnxTynXfEEVuQEcuZgVs6EVs6E666666--)
http://www.murata.com/products/emicon_fun/2012/09/emc_en14.html (http://www.murata.com/products/emicon_fun/2012/09/emc_en14.html)
http://www.tech-dream.com/Seminar/Cal_EMC_Seminar_2010(Intermark_EMI_Absorber).pdf (http://www.tech-dream.com/Seminar/Cal_EMC_Seminar_2010(Intermark_EMI_Absorber).pdf)
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Looking at that I would try just using a few pieces of flat magnet, as it is basically the same, lossy ferrite in a flexible binder. Comes as strips in a fridge door, or for free as magnetic decals, and is self adhesive onto ferrous substrates.
I have tried the magnetic decals, the type you get in the mail advertising phone numbers of dentists etc., but not for this particular application. When I tried to use them as a substitute for ferrite cores by rapping them around wires, etc. the effect was very minimal compared to a real ferrite core. Probably the grade of the magnetic material has to do a lot with their efficacy. I'm with you that the price for a 4" x 4" seems kind of high, so I'm hoping that someone that has used them will shed some light on whether they are worth that price.
Just did an experiment using some advertising that had magnetic backings on them ( the paper went to the recycle bin but not the magnets ;) ) and yes they are pretty useless as EMI absorbers. I made a 12 turn coil ( came in at pretty close to 12uH as well) and looked at the dissipation and Q with or without a pair of these ferrites in the core. Not more than a 1% difference, and even with the magnets holding the core not much change. So I can then say that they will be good to stick wiring down with no problems, but they are as good as berries on a mule at attenuation of RF on wiring.
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Well, I decided to make some mods to psu board and presents step by step the changes.
My psu version is PCB-T115-J REV6 with:
IC1 = R7731 Burst Triple Mode PWM Flyback Controller
IC2 = LM324L-S14_Quad Operational Amplifiers
IC3 = MC34063A-D 1.5A Step up_Step Down Inverting Switching Regulator
The test done to the same conditions (stable room temperature 26°C), SelfCal to Owon and the probe was fixed on the table by the tape.
I measured the oscilloscope at four conditions:
- Without any mod
- With adds two appropriate ferrites on specific cables (see the photo)
- With electrolytic capacitors mod
- With the new capacitors and ferrites
Step 1: Electrolytic Capacitors Changed and how this result to noise pattern
I changed all the Chmec LR Chinese Electrolytic Capacitors (8, except this of 33uF/400V) with the Nippon NCC KY Series. I kept the same capacity/volts for 470uF/16V and 1uF/50V but changed the 22uF/50V by 47uF/63V.
All the spikes has gone and remains only the threshold of noise. The decoupling properties of Nippon is better than Chinese Chmec capacitors and filters spikes better.
A little better result we have with two appropriate ferrites at the cable that connect the psu and adapter board and the battery cable. The ferrites filters and the rest of board noise.
If we combine the ferrites and new capacitors, we have better results but it is very closed to image with the ferrites only (a bit little spikes only).
After spikes eliminated, the next step will be some mods to decrease the noise threshold of psu...
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Well, I decided to make some mods to psu board and presents step by step the changes.
Good work lemon! I'm curious about a couple of things: Did you have any issues putting the scope back together with the ferrites in place? How much of an improvement did you get by adding the ferrite on the red wire versus just the ferrite on the ribbon cable?
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Yes, there is with a large ferrite to ribbon cable. Unfortunately, there is appropriate area inside to Owon for this big ferrite.
See at the attachment photo the red point, this is the problematic place from left handle fixed. You need two parts of flat ferrites, at the beginning and end of the ribbon cable.
The next one smaller ferrite (battery cable) didn't any problem.
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Well, I attached a photo from my pcb board. I have mark with red arrows the changed capacitors.
Step-2: Adding smd decoupling capacitors to all electrolytic capacitors and IC3 - Effects on noise pattern.
Today, around of IC3 (MC34063A-D 1.5A Step up_Step Down Inverting Switching Regulator), all the changed electrolytic capacitors put some smd decoupling capacitors with 1.5nF & 220nF each. I have attached a sample photo of these.
I done some measures with ac and battery operation and I am looking how this effect on pattern noise vs ferrites on cables.
At the final, the smd decoupling decrease more the noise level and there is no need to put ferrite on ribbon cable but this is not happening with battery. With battery operation need the ferrite on this battery cable. For some reason the smd decoupling and the new Nippon capacitors didn't filtering complete the noise.
The adding 2 ferrites on this battery cable doesn't better results. Recommended the use of one small ferrite.
In all these patterns the noise has decreased and periodically there is some more noise signs.
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...the noise pattern...
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My way to improve the "Noise GND" is coming to end.
After psu mods (about this decoupling way, see the message of Siri member and the rest from #928 post), it comes the time of adapter board mods. Same way, everything decoupling capacitors from Step-down converter +3.3V, converter +5.5V to converter +8.8V for LCD display back-light (see some to %959 post). The rf-loop works was helping me a lot of (from Electronics and Owon SmartDS oscilloscopes Forum).
Now the total noise threshold is btw 48-62mV without any ferrite. The noise is the same either ac or battery operation.
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My way to improve the "Noise GND" is coming to end.
After psu mods (about this decoupling way, see the message of Siri member and the rest from #928 post), it comes the time of adapter board mods. Same way, everything decoupling capacitors from Step-down converter +3.3V, converter +5.5V to converter +8.8V for LCD display back-light (see some to %959 post). The rf-loop works was helping me a lot of (from Electronics and Owon SmartDS oscilloscopes Forum).
Now the total noise threshold is btw 48-62mV without any ferrite. The noise is the same either ac or battery operation.
Good work lemon! Thanks for all the updates. I will be soon ordering some supplies to try to reduce the GND noise without altering the circuit boards. Right now my primary candidates are ferrites designed to fit ribbon cables and ferrite based pressure sensitive EMI absorbent material.
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Thanks TomC.
For the ribbon flat cable look those at post #966. Probably is the best for this area. Additional add a small one to the battery cable and you are OK without problems to warranty.
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I got a feeling that the noise issue may have been recently resolved by OWON as my noise level is less 5mV although bit spiky it is not as bad a 50mV. I am not sure how to open my scope but as it is at an acceptable level then I don't particularity want to open it.
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Yes, from other information that I had (version 1312XXXX), the Owon has decrease the issue with the "noise gnd".
5mV is very low noise for fullBW, are you sure that you test it in full BW? I think that you have measured with BW limited.
Please, repeat the test with the following procedure.
Set the probe and cable as the following photo at the right side.
(https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/?action=dlattach;attach=52103)
- Make a Calibration procedure as the manual describe.
- Compensate the probe as manual describe.
- Change switch probe to 10x.
- Do the same and with the Probe Owon Menu (10X).
- Connect probe to Probe Comp and GND wire to GND.
- Turn CH2 off.
- CH1 to DC, 50mV/Div.
- Push Trigger 50%
- Set the Acquire Mode to Peak and Length to 1M
- Set the Horizontal speed to 100us
- Set the measurement to Voltage peak to peak (Vp to Owon) and write the value.
Finally take a capture (png format) and upload the pattern of noise gnd
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The Acquire length was the difference, hard to keep up with an 88 page thread. After changing the length to 1M the noise figure increased to 26mV not BW limited. I had the acquired length at 10K before and the sample method not peak.
Still comparatively better but not overly. I currently don't have anything to save onto as my lab is strewn all over the place. Have saved it internally but got a weird Pk-Pk reading of 260mV which equates to a measuring issue. So I used the cursor to measure the noise value at 26mV. mmmm
Have exams to deal with ATM so I don't have a lot of time to fiddle about.
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26mV peak to peak, very nice noise gnd!
Can you remember me what S/N have you had (without the last numbers)?
I am afraid that the following, I don't understand! What is ATM?
...Have exams to deal with ATM so I don't have a lot of time to fiddle about.
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I am afraid that the following, I don't understand! What is ATM?
ATM = At The Moment
You'll get used to these TLAs :-)
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Hi, ATM correct digsys, sorry lemon, I'll try not use non electro acronyms.
S/No SDS7102131XXXX.
Other than a basic scope it is turning out to be a nice scope. My level of capability would require a higher level scope money is a real restriction for me to afford even a Rigol 2000 series.
The only issue I have is the LAN feature, any time I use the LAN the scope freezes. That is really weird.
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Thanks for the info Digsys!
1X week of 2013 is the production of your ocilloscope.
With the same production 12w2013 an other person, said at the Electronics ans Smart SDS Finland Forum that measured 126mV noise gnd without any spikes (peak to peak and with Mode Peak).
You have the best noise AFAIK ( :D )
I don't use the LAN capability, but if you see the post #1285 there is a list with "what Owon must to correct to the next fw". There is a reference for the LAN "The LAN interface was crippled by slow speed from the beginning. With the latest firmware patches it has been further crippled by a non-functional image transfer, and a flaky high depth memory transfer that in certain cases causes the DSO to freeze."
This list has sending to Owon (info@owon.com.hk) but there is no respond until now.
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I understand that the noise issue was going to be resolved in the updated version that went into production in the beginning of June. Can anybody confirm that this new version is in production? Does anybody know if this updated version is available for sale yet? I also wanted to confirm that the new version would be SDS71021323xxx or above
Thanks in advance for the info!
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The S/N of member mswhin63 is SDS7102131XXXX.
That's meaning a date of production 1X week of 2013. As you can see the noise was very low.
It is logical, all the scopes with the date of production bigger or equal of this to have the same behaviour at the "noise gnd".
I have no other information about this.
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I understand that the noise issue was going to be resolved in the updated version that went into production in the beginning of June. Can anybody confirm that this new version is in production? Does anybody know if this updated version is available for sale yet? I also wanted to confirm that the new version would be SDS71021323xxx or above
Thanks in advance for the info!
dgmoore78@yahoo.com, Post #1195 contains the following message that I left at Owon's tech support beggining of June:
---------------------------------------------------------------------------------------------------------------
Dear Owon Tech support:
This is a follow up to my April 4, 2013 inquiry to which I did not receive a response. I bought my SDS71021246320 from Saelig in the USA on January 17, 2013. As I previously stated this is one of the units that has the "GND noise issue". This is the issue extensively discussed in the EEVblog and ForumUp forums on the internet. A DIY for modifying the PSU & adapter boards has also been posted but unfortunately it voids the Owon Warranty. It's been reported that Owon may be starting mass production of improved PSU and Adapter boards that include this modification during the month of June. I would greatly appreciate a response to the following questions:
1. Will the "GND noise" significantly decrease if these new boards are installed in my unit?
2. Will the Owon Warranty cover replacement of these boards in units affected by the "Gnd noise" issue?
3. Can I obtain these boards so I can fix my scope myself either free under the Warranty or at a discount if this is not possible?
A prompt and detailed response will be greatly appreciated.
Best regards,
---------------------------------------------------------------------------------------------------------------
Post #1199 contains the response I got from Owon and my interpretation of it's meaning:
----------------------------------------------------------------------------------------------------------------
"Thank you for purchasing OWON product.
As to GND noise, we have noticed there is noise, but it is not the one will affect your testing result, as you know, every scope has noise affect by testing environment.
We have not plan and exact date to make change for it now, because it is not quite abnormal. Unlike the ones said in the blog.
Thank you for understanding. "
--------------------------------------------------------------------------------------------------------
If I understand this correctly, they are saying that:
1. They know there is noise.
2. In their opinion the noise doesn't affect testing.
3. That this noise is similar to other external sources of noise you may encounter while using the scope.
4. That making changes to correct this noise is not a priority because it is closer to normal than abnormal.
5. That either the noise they see or the influence they believe it has in the usability of the scope doesn't match what is said about it in the EEVblog.
6. That they are hoping that the customer finds this explanation acceptable.
As I stated before, I view the GND noise on my scope as just an inconvenience. So I can't argue that some of the statements made by Owon are untrue. However, I find it strange and inappropriate, that a test equipment manufacturer would justify an obvious flaw in their equipment by pointing out the existence of external similar conditions that mimic it. Similarly, a car manufacturer could justify a car that pulls slightly to the right on a straight and level road, by reminding the customer that common road conditions would require him to steer in a similar way anyway.
In the end, Owon didn't directly answer the questions regarding Warranty coverage. However, the tone of the message leaves little doubt in my mind that at least at present they don't plan to offer Warranty coverage or any kind of a discount.
Ultimately, Owon will have to live with the results of their actions. Saving a few dollars now may seem as a wise financial decision. But only time will tell the actual cost of disappointing current customers and causing prospective buyers to take pause.
--------------------------------------------------------------------------------------------------------------
If we are to believe that Owon is telling the truth, then any reports of newer scopes exhibiting lower GND noise levels is purely coincidental and doesn't guarantee that purchasing a scope manufactured after the beginning of June will give you similar results.
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Thanks for the information lemon and Tom.
I found a seller who was able to get me a unit from the June production run. It will take me a few weeks to get it since it is being shipped directly form China. I will let you all know how it works out.
...fingers crossed!
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Good luck!
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I have seen here some nice works, lemon etc..
-----------------------
Just for know:
Owon sell also spare parts.
If you are out of warranty and you have fail in scope (example some kind of self made damage), or even front or backside case broken (if example dropped)
Most expensive is whole mainboard.
But other parts prices without delivery (it depends...) are very reasonable priced.
Of course if you buy all parts it is of course some amount more expensive than whole new scope.. (but not very much.... )
Power supply,
adapter board
front panel board(s)
TFT module
main board
front and back cover
etc
Of course it is best to contact local seller who have contract with Owon then it may be more easy...
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Yes, and far as I know OWON accept bank transfers.
New PSU and DC/DC board cost ~ USD 50 (postage included). :)
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Thanks for the information lemon and Tom.
I found a seller who was able to get me a unit from the June production run. It will take me a few weeks to get it since it is being shipped directly form China. I will let you all know how it works out.
...fingers crossed!
Hope it all works out for you! In any case, the scope is still a good buy for the money, and the GND noise problem, as far as I'm concerned, is not a deal breaker.
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Yes, and far as I know OWON accept bank transfers.
New PSU and DC/DC board cost ~ USD 50 (postage included). :)
That is good news! Would you mind posting how you got the price information. Thanks.
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Yes, and far as I know OWON accept bank transfers.
New PSU and DC/DC board cost ~ USD 50 (postage included). :)
That is good news! Would you mind posting how you got the price information. Thanks.
I just ask to OWON. That's the price that I got, USD 50.
Note: Owon warranty don´t cover replacement of these boards.
About three weeks ago they have solved this gnd noise problem, told me a Owon´s employee.
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I just ask to OWON. That's the price that I got, USD 50.
About three weeks ago they have solved this gnd noise problem, told me a Owon´s employee.
Thanks, I 've contacted Owon about purchasing these boards. We'll see what they say!
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I just ask to OWON. That's the price that I got, USD 50.
About three weeks ago they have solved this gnd noise problem, told me a Owon´s employee.
Thanks, I 've contacted Owon about purchasing these boards. We'll see what they say!
Good luck!
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Hey guys,
Just received my new scope today from Hong Kong and wanted to give everybody an update on my "noise test". My Manufacturing Date code is 1319 (SN#SDS71021319xxx)
Peak Detect:
Vp=54 mv
Vk: 17 mv
Average:
Vp=44
Vk=12
:-+
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Very well!
The noise is low without any peaks.
The member "rf-loop" had suggested a method for this.
Procedure for measurent of Noise GND
----------------------------------------------------
Make a Calibration procedure as the notes says (look in manual).
Compensate the probe as manual described.
Change switch probe to 10x.
Do the same and the Probe Owon Menu (10X).
Connect probe to Probe Comp and GND wire to GND. Fix the cable of probe like the attachment photo.
Turn CH2 off.
CH1 to DC, 50mV/Div.
Push Trigger 50%
Set the Acquire Length to 1M and the Mode to Peak
Set the Horizontal speed to 100us
Set the measurement to Voltage peak to peak (Vp to Owon) and write the value.
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Very well!
The noise is low without any peaks.
The member "rf-loop" had suggested a method for this.
Procedure for measurent of Noise GND
----------------------------------------------------
Make a Calibration procedure as the notes says (look in manual).
Compensate the probe as manual described.
Change switch probe to 10x.
Do the same and the Probe Owon Menu (10X).
Connect probe to Probe Comp and GND wire to GND. Fix the cable of probe like the attachment photo.
Turn CH2 off.
CH1 to DC, 50mV/Div.
Push Trigger 50%
Set the Acquire Length to 1M and the Mode to Peak
Set the Horizontal speed to 100us
Set the measurement to Voltage peak to peak (Vp to Owon) and write the value.
I updated my test process with your suggestion.
Vp=34mV
Let me know if you would like me to try anything else.
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I've been considering the DIY options available, including the cost of materials and risk of voiding the Owon's Warranty, to reduce the GND noise on my scope. Yesterday I decided that the best option for me was to order a new PSU board and a capacitor to modify the Converter board from Owon. For those interested in the details, I've posted below the e-mails leading to this decision as well as the purchase transaction.
The agent responding to my e-mails is the same agent that previously indicated that Owon ---- "have not plan and exact date to make change for it now, because it is not quite abnormal" ---- referring to the GND noise. The good news is that he now confirms that changes in the PSU & Converter boards at least reduce the noise.
For those of you that have been holding out for a resolution of the GND noise issue before making a purchase decision, Owon's response seems to confirm previous reports of an early June resolution to the GND noise issue. If you are still cautious, check the forum in the coming weeks, I plan to post noise images before and after exchanging/upgrading the boards in my scope. Hopefully you can use these images to help you decide if the noise level is good enough for you.
As for those of us that already own a scope with the GND noise issue, Owon's response offers an alternative to a DIY solution for US $50 + money transfer fees. This is not as good as the free exchange that many of us believe Owon should have offered, but to me, it's not a totally unreasonable price to pay to improve the usability of your scope.
The bad news, at least for me, is that my bank charged me a $45 fee for the money transfer. Maybe doing the transfer via Western Union is less expensive if you can make it work. I have an account with them but I couldn't get their Web site to give me the option to transfer funds to a Bank Account in China. Maybe I didn't try hard enough or should have called them before giving up, but I just got impatient and used my bank's money transfer service instead.
I plan to open my scope later today to get acquainted with the procedures I'll need to perform when the Owon shipment arrives. While I'm at it I'm going to try ferrite cores in the cable between the PSU and the converter board, as well as from the converter board to other scope components. I'll be posting the results as soon as I get done.
------------------------------------------------------------------------------------------------------------------
To: _____ (at Owon)
Subject: Re: GND Noise
Dear _____ or other Tech Support agent,
One of your customers reports that during a recent communication with Owon, one of your employees has indicated that the GND noise issue was resolved about three weeks ago. He also reported that Owon can supply the new boards (PSU & Adapter DC/DC) for about US $50. In an effort to resolve, or at least improve the GND noise on my unit, I would like to purchase these boards from you if they are indeed available. Please indicate the actual price and what needs to be done to complete this transaction.
Best regards,
------------------------------------------------------------------------------------------------------------------
To: _____ (TomC)
Subject: GND Noise
Hi _____,
Sorry for my mistake information, after consulting about if from our engineer, I found this GND noise has reduced much by replacing new board. But please note that the noise can’t be solved 100%, but reduced.
Only two spares need to be replaced, one is Power Supply Board and the other is a Capacitance in convert board.
The price include shipping cost to USA is USD50 totally. Please pay to our bank account. (paypal or credit card are not acceptable, but western union is preferable)
If you agree, please tell me your below information:
Your address
Consignee
Telephone number
Our bank account is
BANK INFO
\\\\\\\\\\\\\\\\\\\\\
||||||||||||||||||||| (I didn't post names or the bank information to protect privacy, but the bank information
||||||||||||||||||||| provided contained everything I needed to transfer funds from my bank account to their bank
||||||||||||||||||||| account)
\\\\\\\\\\\\\\\\\\\\\
You could make payment firstly.
Have a nice day
------------------------------------------------------------------------------------------------------------------
To: _____ (at Owon)
Subject: Re: GND Noise
Hi ______,
I just transferred USD50 to your bank account for the new boards. You should receive e-mail from my bank in my behalf shortly. My Address information is as follows:
\\\\\\\\\\\\\\\\\\\\\\\\\\
||||||||||||||||||||||||||
//////////////////////////
My telephone number is:
||||||||||||||||||||||||||
------------------------------------------------------------------------------------------------------------------
To: _______ (TomC)
Subject: Re: GND Noise
Hi ______,
We got your payment, thank you.
We will make shipment soon.
Attached is to show the capacitance I mentioned need to be replaced.
Have a nice day
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While I had my scope open today, I installed some ferrites to see how much I could improve the GND noise.
The first picture shows the ferrites on the cables coming out of the converter board. The blue heat shrink on the left is covering a very small solid ferrite that I salvaged from discarded equipment. So all I can tell you about this one is that it is about .25" outside diameter and the inside diameter is just large enough to hold the two wires. The wires had to be pulled out off of the connector to install the ferrite. The ferrite on the small ribbon cable is a standard snap on small ferrite purchased at Radio Shack.
The second picture shows a medium size snap on ferrite on the ribbon cable between the PSU and the Converter board. This is also a standard ferrite purchased at Radio Shack. However, even this medium size ferrite is too large and doesn't allow the scope's cabinet to snap back together.
The third picture shows what I did to allow enough room for the cabinet to snap together. The ferrite halves can be easily removed from the snap on housing, and then held together with a cable tie.
The next 6 pictures show the GND noise before the ferrites were installed (first 3 pictures) and after the ferrites were installed and the scope was put back together (last 3 pictures).
Besides the improvement on the GND noise, I also found out that the amount of noise produced by placing the probe's cable next to the TFT panel was also greatly reduced from what I remember to have experienced in the past. I didn't think to get images before I installed the ferrites, so I'm only relying on memory for this last comment.
When I get the shipment from Owon, I plan to try the new board with and without ferrites, to see if it makes any kind of a difference.
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Very well!
The noise is low without any peaks.
The member "rf-loop" had suggested a method for this.
Procedure for measurent of Noise GND
----------------------------------------------------
Make a Calibration procedure as the notes says (look in manual).
Compensate the probe as manual described.
Change switch probe to 10x.
Do the same and the Probe Owon Menu (10X).
Connect probe to Probe Comp and GND wire to GND. Fix the cable of probe like the attachment photo.
Turn CH2 off.
CH1 to DC, 50mV/Div.
Push Trigger 50%
Set the Acquire Length to 1M and the Mode to Peak
Set the Horizontal speed to 100us
Set the measurement to Voltage peak to peak (Vp to Owon) and write the value.
I updated my test process with your suggestion.
Vp=34mV
Let me know if you would like me to try anything else.
You have very well noise level. Thanks for this information.
Now, there is no any problem to any low level signal for measurement.
You have the last improvement psu version of Owon.
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@ TomC = Very informative all of this!
It is a pitty than Owon don't take money from Paypal or Credit Card.
As I can understand, the Owon has complete changed the psu board and makes only a capacitance change to adapter board.
TomC, they told you that the only change on adapter board is a capacitance to the specific area. Have you sent your s/n before about this or it is not related?
You have better results of noise level with the ferrites. You found a solution with the ribbon cable, very well!
With the new psu board, you 'll see if the ferrites will be usefull. We'll waiting for results.
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I received my SDS7102V yesterday. I asked for the new version produced in June and the seller agreed, but they still sent me an old version (S/N is 1303xxx). The gnd noise is terrible, Vp-p is up to 160mV and lots of spikes. I asked for an exchange or refund and waiting for their answer.
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IMHO the best thing is to stop buying Owon all together, at least for 6 months untill the bad stock is sold or returned. I have SDS7102 from 2011, but now I wouldn't buy it, I would wait or buy something else.
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I agree. It was a mistake to buy it now.
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So never buy online. Buy a unit that you check for noise problems before.
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TomC, they told you that the only change on adapter board is a capacitance to the specific area. Have you sent your s/n before about this or it is not related?
They have my serial number, but I don't now if this same mod applies to other serial numbers. The 1000pf SMD capacitor, where they show it, is directly underneath an electrolytic capacitor on the component side, so it's only bypassing it to help high frequency filtering. The adapter board in my scope looks exactly like the adapter board in the picture, except that it doesn't have the SMD capacitor.
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I received my SDS7102V yesterday. I asked for the new version produced in June and the seller agreed, but they still sent me an old version (S/N is 1303xxx). The gnd noise is terrible, Vp-p is up to 160mV and lots of spikes. I asked for an exchange or refund and waiting for their answer.
I bought mine from a dealer on E-Bay (SMTZONE) that shipped the unit directly from Hong Kong. Mine is from the new June batch and is very good.
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TomC, they told you that the only change on adapter board is a capacitance to the specific area. Have you sent your s/n before about this or it is not related?
They have my serial number, but I don't now if this same mod applies to other serial numbers. The 1000pf SMD capacitor, where they show it, is directly underneath an electrolytic capacitor on the component side, so it's only bypassing it to help high frequency filtering. The adapter board in my scope looks exactly like the adapter board in the picture, except that it doesn't have the SMD capacitor.
When you received the new psu board, please give us some photos from up and down side.
Also, can you give us the adapter version that you have?
At the last, can you measure the noise with the bypassing (1000pF) only? Before, you installed the new psu board.
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TomC, they told you that the only change on adapter board is a capacitance to the specific area. Have you sent your s/n before about this or it is not related?
They have my serial number, but I don't now if this same mod applies to other serial numbers. The 1000pf SMD capacitor, where they show it, is directly underneath an electrolytic capacitor on the component side, so it's only bypassing it to help high frequency filtering. The adapter board in my scope looks exactly like the adapter board in the picture, except that it doesn't have the SMD capacitor.
When you received the new psu board, please give us some photos from up and down side.
Also, can you give us the adapter version that you have?
At the last, can you measure the noise with the bypassing (1000pF) only? Before, you installed the new psu board.
+1 for that! It definitely looks like a simple modification that most of us will be able to do and looks easy to undo, should there be any warranty issues.
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TomC, they told you that the only change on adapter board is a capacitance to the specific area. Have you sent your s/n before about this or it is not related?
They have my serial number, but I don't now if this same mod applies to other serial numbers. The 1000pf SMD capacitor, where they show it, is directly underneath an electrolytic capacitor on the component side, so it's only bypassing it to help high frequency filtering. The adapter board in my scope looks exactly like the adapter board in the picture, except that it doesn't have the SMD capacitor.
Boy, you're really going all out to reduce a noise level I never thought was all that terrible. Your original figure was somewhat higher than my gen-one version but not nearly as bad as some. (Remember electroguy claimed 800mV !) With the ferrites you installed yours now measures slightly LOWER than mine, which is about 80mV under the same test conditions.
I actually tried installing ferrites on mine today but it there was no noticeable reduction. My boards are also different than most shown here (see photos). That was all I was willing to attempt as it's not a real-world issue. I never get that much noise when probing something. In fact just doing the 'standard noise test' with a short (spring) ground cuts the level by more than half.
Good luck with your modifications!
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Just a quick question: Does the metal part of anyone else's top power switch get hot during operation? I noticed that mine does some time ago, but looking at the power board I couldn't find any obvious sources of heat that it could be dissipating. In the vicinity, there's a component in an isolated TO-220 package that's connected to the Z-plate and that's about it. Everything else seems cool when touched.
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@ rstoer
You have an SDS7102 of 27th week of 2011. An older version that we have.
As your main psu board as adapter board are very different from newer models.
Yours results with 80/36mV are with a long/short ground cable. The 80mV initial noise level are very well.
Please look at post #1330 and repeat your test noise with these parametres (same conditions to all)
But I don't understand, there is no any improvement with ferrites in yours boards? IMHO only that two ribbon cables btw psu and adapter boar needs ferrites.
As your noise gnd level is lower as better you can measure low signals. Ground noise issue isn't Owon part, many other oscilloscopes have the same issues.
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Just a quick question: Does the metal part of anyone else's top power switch get hot during operation? I noticed that mine does some time ago, but looking at the power board I couldn't find any obvious sources of heat that it could be dissipating. In the vicinity, there's a component in an isolated TO-220 package that's connected to the Z-plate and that's about it. Everything else seems cool when touched.
Andrejako, the top metal of power switch is connected to gnd of psu board (it doesn't needs, because it sends EMI like antenna, everywhere).
All the versions of psu boards are no identical. Some of these have a first mosfet (I think 5n60L) that really hots. If someone allumium heatshink connects with gnd of board...it hots all the gnd path!
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Hi,
How do you save ch1 and ch2 at the same time?
How do you save ch1 ch2 and math or fft at the same time?
JP
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Hi,
How do you save ch1 and ch2 at the same time?
How do you save ch1 ch2 and math or fft at the same time?
JP
Do you mean how to save in image file?
You can save the 2 channels or fft or maths in usb stick or via your computer and the Owon PC Oscilloscope software.
With at once 2 channels and fft you can't (I think) but there is a click option to Owon PC Oscilloscope software that you can see the channels or fft at the same image.
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can someone please export two specific csv's from an Owon?
one when Owon ch1 enabled, no signal connected, AC counpled, timebase set to 500us/DIV, 10Mpoint, 1GS/s and the first volt/div with no bw reduction, so i think 5mV/DIV. And then second one with same settings but ch1 set to gnd.
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I meant ch1 ch2 on a usb key.
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I meant ch1 ch2 on a usb key.
I haven't this time the oscilloscope in front of me.
From my memory, this saved is easy with Owon PC Oscilloscope Software.
I see now the pdf manual, at pages 49-50 described the "How to Save and Recall a Waveform"
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can someone please export two specific csv's from an Owon?
one when Owon ch1 enabled, no signal connected, AC counpled, timebase set to 500us/DIV, 10Mpoint, 1GS/s and the first volt/div with no bw reduction, so i think 5mV/DIV. And then second one with same settings but ch1 set to gnd.
I am on summer holidays and I haven't the scope together.
I remember that saves direct in bin format but maybe the Owon Software can to save at csv, otherwise some member will give you the bin file and you will convert to csv format with a converter.
At the first case, the 5mV/div will limit the BW probably, you must set to 10X the Probe Set to full BW.
At the second case, you probably want the "Ground Noise" (both the tip and ground clip to ground). For this we have follow the procedure that described to #1330 post.
Perhaps members like TomC or dgmoore78@yahoo.com can help you by csv or bin files.
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When you received the new psu board, please give us some photos from up and down side.
Also, can you give us the adapter version that you have?
At the last, can you measure the noise with the bypassing (1000pF) only? Before, you installed the new psu board.
I got the tracking number from Owon and the package is already in the US, so it will probably be delivered by Saturday or Monday. I'll post pictures as well as the other information you want.
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Boy, you're really going all out to reduce a noise level I never thought was all that terrible. Your original figure was somewhat higher than my gen-one version but not nearly as bad as some. (Remember electroguy claimed 800mV !) With the ferrites you installed yours now measures slightly LOWER than mine, which is about 80mV under the same test conditions.
I actually tried installing ferrites on mine today but it there was no noticeable reduction. My boards are also different than most shown here (see photos). That was all I was willing to attempt as it's not a real-world issue. I never get that much noise when probing something. In fact just doing the 'standard noise test' with a short (spring) ground cuts the level by more than half.
Good luck with your modifications!
What can I say, I'm retired, got to find something to do!
One thing I noticed on your scope is that the noise level using the short spring ground is more than twice the noise on the newer scopes. On mine the baseline noise (nothing connected to the BNC) is about 12mV, then, with the probe and short ground clip connected to the ground lug it increases by 2mV for a total of 14mV.
That makes me think that the signal path of scopes like yours was more polluted with noise than the newer scopes. That noise in the signal path is differential noise, different from the common ground noise that we are experiencing with the current GND noise issue. So it doesn't surprise me too much that the ferrites didn't make that much difference, because they only help with the common mode noise, and it seems you have very little to begin with, 80 - 36 = 44mV.
Since, you don't have any issues when probing signals, I imagine this includes low level signals, then, overall, I think your scope's usability is probably better than the newer ones. For scope's like ours, if you want to view and trigger on low level signals while using full bandwidth, you are forced to use a short spring ground.
The only other alternative is to limit the bandwidth to 20MHz or set the probe to X1 which limits the bandwidth to 6MHz.
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Just wondering, how did it pass the EMI test?
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I meant ch1 ch2 on a usb key.
With the type set to Wave, as far as I know, you can only save one channel at a time or math. Once saved, however, you can display up to 8 saved waveforms simultaneously.
With the type set to Image, you automatically save whatever is on the screen, this includes both channels & math.
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can someone please export two specific csv's from an Owon?
one when Owon ch1 enabled, no signal connected, AC counpled, timebase set to 500us/DIV, 10Mpoint, 1GS/s and the first volt/div with no bw reduction, so i think 5mV/DIV. And then second one with same settings but ch1 set to gnd.
I don't know of a way to export CSV files from the Owon. The attachments are binary files (.bin renamed to .hex) with the scope setup as you specified and the corresponding images so you can see what the waveforms looked like. I assumed that by no signal you meant nothing connected to the BNC. Hope that helps.
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Just wondering, how did it pass the EMI test?
mlhstock, 160mVpp is in the normal range for scopes prior to the June production with modified PSU & Adapter boards. So provided you did the test using the setup guidelines suggested in recent posts, your scope's performance in this respect is similar to what other of us have been experiencing. On my scope, before I added some ferrites, the GND noise level was in the range of 145mVpp.
However, as I understand it, you were promised a scope from the June production. If I was in your shoes, I would try to convince the dealer to stand by their promise. I would state the facts without getting angry, and elevate the complaint to higher management if necessary. As a last resort, I would complain directly to Owon, explain the circumstances, and try to get at least new components to get my scope up to date.
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can someone please export two specific csv's from an Owon?
one when Owon ch1 enabled, no signal connected, AC counpled, timebase set to 500us/DIV, 10Mpoint, 1GS/s and the first volt/div with no bw reduction, so i think 5mV/DIV. And then second one with same settings but ch1 set to gnd.
I don't know of a way to export CSV files from the Owon. The attachments are binary files (.bin renamed to .hex) with the scope setup as you specified and the corresponding images so you can see what the waveforms looked like. I assumed that by no signal you meant nothing connected to the BNC. Hope that helps.
TomC, he asked the first scale of Volts (2mV/div or 5mV/div). For what I remember, the SDS limited automatically the BW at these scales. Set the menu "Probe Set" to 10X and repeat the measurement.
There are many convertors "bin to csv", so there is no any problem with the bin files.
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There are many convertors "bin to csv", so there is no any problem with the bin files.
I'm out from work and can not do it now but with this computer here was old Owon PC soft .11.
With Owon PC software you can convert bin file to .txt, .xls and .csv.
If there is twi channel in use then there is Ch1 and Ch2 selection. If convert both it go to same file
something like this. (this is not from example image how to use PC soft)
In example image, there is 1M memory Ch1 and it produce around 13M .csv
(it was only Owon .bin file in this computer what I find)
(from Owon PC soft example files becouse it have two channel together)
First some information bytes
sample no,Ch1,Ch2
1,-600.00,3440.00
2,-600.00,3360.00
3,-600.00,3440.00
4,-600.00,3360.00
5,-600.00,3440.00
6,-600.00,3360.00
7,-600.00,3440.00
8,-400.00,3360.00
9,-600.00,3440.00
10,-400.00,3360.00
...
In PC soft, (of course first open stored .bin file from PC or USB memory and then... ) first open View, select data table, select sequence, Ch1 and/or Ch2 and then Save as...
Select file type and save. (10M bin to .csv take some time... and result is over 100M if one channel)
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There are many convertors "bin to csv", so there is no any problem with the bin files.
I'm out from work and can not do it now but with this computer here was old Owon PC soft .11.
With Owon PC software you can convert bin file to .txt, .xls and .csv.
If there is twi channel in use then there is Ch1 and Ch2 selection. If convert both it go to same file
something like this. (this is not from example image how to use PC soft)
In example image, there is 1M memory Ch1 and it produce around 13M .csv
(it was only Owon .bin file in this computer what I find)
(from Owon PC soft example files becouse it have two channel together)
First some information bytes
sample no,Ch1,Ch2
1,-600.00,3440.00
2,-600.00,3360.00
3,-600.00,3440.00
4,-600.00,3360.00
5,-600.00,3440.00
6,-600.00,3360.00
7,-600.00,3440.00
8,-400.00,3360.00
9,-600.00,3440.00
10,-400.00,3360.00
...
In PC soft, (of course first open stored .bin file from PC or USB memory and then...:) first open View, select data table, select sequence, Ch1 and/or Ch2 and then Save as...
Select file type and save. (10M bin to .csv take some time... and result is over 100M if one channel)
Thanks rf-loop, now I know how to convert the .bin files to .csv for tinhead.
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can someone please export two specific csv's from an Owon?
one when Owon ch1 enabled, no signal connected, AC counpled, timebase set to 500us/DIV, 10Mpoint, 1GS/s and the first volt/div with no bw reduction, so i think 5mV/DIV. And then second one with same settings but ch1 set to gnd.
Thanks to rf-loop's post I was able to convert to .csv. Here are the files renamed to .txt.
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TomC, he asked the first scale of Volts (2mV/div or 5mV/div). For what I remember, the SDS limited automatically the BW at these scales. Set the menu "Probe Set" to 10X and repeat the measurement.
There are many convertors "bin to csv", so there is no any problem with the bin files.
lemon, the probe menu was set to X10, that's why on the image it shows 50mV, but in reality the scope is internally set to 5mV/Div. With the help of rf-loop's post I was able to convert the .bin files to .csv and post them already converted for tinhead. Probably he had already found a way to convert them himself, but just in case I posted them too.
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Just wondering, how did it pass the EMI test?
mlhstock, 160mVpp is in the normal range for scopes prior to the June production with modified PSU & Adapter boards. So provided you did the test using the setup guidelines suggested in recent posts, your scope's performance in this respect is similar to what other of us have been experiencing. On my scope, before I added some ferrites, the GND noise level was in the range of 145mVpp.
However, as I understand it, you were promised a scope from the June production. If I was in your shoes, I would try to convince the dealer to stand by their promise. I would state the facts without getting angry, and elevate the complaint to higher management if necessary. As a last resort, I would complain directly to Owon, explain the circumstances, and try to get at least new components to get my scope up to date.
Thanks, TomC. Yes, the dealer made a proposal that they will send me "a low-noise board" (I assume it's PSU) and I accepted the proposal. They asked me to replace the board myself and won't void my 3 year warranty.
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I bought mine from a dealer on E-Bay (SMTZONE) that shipped the unit directly from Hong Kong. Mine is from the new June batch and is very good.
I bought one recently on E-Bay (SMTZONE) with serial SDS7102 1312 517
Is this a new batch?
As I am a newbe I dont know what to think. Where is the explaination of the spring test?
What kind of capacitor is the 1000pF SDM: ceramic, metal, etc.?
See attached the noise test as described in msg #1332
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Your oscilloscope was made of 12th week of 2013 (at the end of March).
You measured the square pulse test (1KHz) not the ground noise.
Please look the same post as before at the attachment photo.
Fix the cable like this and connect both the tip and long ground cable (clip) to the same place (ground).
Follow again the procedure and capture the peak of noise.
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I bought mine from a dealer on E-Bay (SMTZONE) that shipped the unit directly from Hong Kong. Mine is from the new June batch and is very good.
I bought one recently on E-Bay (SMTZONE) with serial SDS7102 1312 517
Is this a new batch?
As I am a newbe I dont know what to think. Where is the explaination of the spring test?
What kind of capacitor is the 1000pF SDM: ceramic, metal, etc.?
See attached the noise test as described in msg #1332
As far as I know the first 2 digits of the s/n, in this case 13, is the year (2013 in this case). The next 2 digits, in this case 12, is the week of the year. So your scope was built during the 12th week of 2013. Not quite the June batch, but scopes built during this period have been reported by other members to have lower GND noise than earlier batches. Member dgmoore78@yahoo.com's scope is 1319, so it was built during the 19th week of 2013, which is not quite June, but it's very close. We don't know exactly when Owon started phasing in the PSU and Adapter board changes, judging by dgmoore78@yahoo.com test results, it probably was a little earlier than June.
On your noise test you have the probe connected as you would to perform the compensation adjustment, this doesn't give you a good idea of the GND noise. You need to connect both the probe and the long ground wire to the scope's probe compensation GND lug. You also need to make sure that the scope's bandwidth is not limited, the image you posted shows BW where the Volts/Div setting is displayed, this indicates that you had the 20MHz bandwidth limit turned on. The noise is a low level signal, so you need to set the scope to the lowest Volt/Div setting that doesn't automatically limit the bandwidth, this is 50mV/Div when you tell the scope that you are using a X10 probe. Finally, you have to set the probe's switch to X10, this is because the X1 setting changes the bandwidth of the probe to about 6MHz. Post #1330 summarizes what you have to do, if you want more details see post #1066.
The package where you received the probes contains a small spring clip that can be used instead of the long ground wire. If you use this spring for your ground connection the GND noise issue should just about disappear. You can test this the same way as explained above, just use the spring clip instead of the long ground wire.
The 1000pF SMD capacitor is most likely a ceramic capacitor, I just received the shipment from Owon, so I'm going to take a look and see what's in there.
Good luck with your new scope, and post the test results again.
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TomC, you just received the shipment of Owon...we 'll waiting for the tests! :)
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TomC, you just received the shipment of Owon...we 'll waiting for the tests! :)
Here are some photographs of what came in the shipment, tests will come later. The small package contains 2 power button caps, maybe they are expecting an accidental breakage. It also contains about six extremely small SMD capacitors, I may need to get new glasses to tackle those! I only need to install one, but the other 5 may be good practice.
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I bought mine from a dealer on E-Bay (SMTZONE) that shipped the unit directly from Hong Kong. Mine is from the new June batch and is very good.
I bought one recently on E-Bay (SMTZONE) with serial SDS7102 1312 517
Is this a new batch?
As I am a newbe I dont know what to think. Where is the explaination of the spring test?
What kind of capacitor is the 1000pF SDM: ceramic, metal, etc.?
See attached the noise test as described in msg #1332
As far as I know the first 2 digits of the s/n, in this case 13, is the year (2013 in this case). The next 2 digits, in this case 12, is the week of the year. So your scope was built during the 12th week of 2013. Not quite the June batch, but scopes built during this period have been reported by other members to have lower GND noise than earlier batches. Member dgmoore78@yahoo.com's scope is 1319, so it was built during the 19th week of 2013, which is not quite June, but it's very close.
Here is another ground test.
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Here is another ground test.
The noise level on this image seems to be a little higher than average, but by no means as high as has been reported by a few others. It's possible that some of this noise is not originating from the Owon. To see if this is the case try performing the test away from computers, fluorescent lights, and other electronic equipment. Also, the Owon's TFT panel (screen) radiates noise that we don't usually consider for this test, so keep the probe's cable as far away from the TFT panel as possible when performing the test. See post #1330 for a picture on how to position the probe cable for consistent results.
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The new PSU board and the modified Adapter board are in. In general, I'm disappointed with the performance of this upgrade. Without ferrites, the new boards barely approximate the results I previously obtained by just adding ferrites when the old PSU was installed. Combining ferrites with the new boards don't improve the situation in most respects, the only exception is when the probe's cable is positioned next to the TFT panel. In this case you can see a significant change in the noise level.
The following images illustrate the tests I performed. There are four images for each test, sample mode, peak detect mode, average mode, and peak detect mode with the probe's cable next to the TFT panel. The conditions for the 3 tests I performed are as follows:
Test 1 - Old PSU in combination with a modified Adapter Board and no ferrites installed anywhere.
Test 2 - New PSU in combination with a modified Adapter Board and no ferrites installed anywhere.
Test 3 - New PSU in combination with a modified Adapter Board and 3 ferrites installed as I showed in post #1333.
Because captured images don't often convey the dynamics of what is happening, I initially captured 5 consecutive images of the same type as each posted image. The images posted are the one's with the highest noise values. So keep this in mind realizing that the noise fluctuates lower than what is shown in these images.
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For those interested in the Adapter board modification, here is one image illustrating the capacitor installed ( my wife's eyebrow tweezers came in handy to hold and position that little SMD capacitor ). The other image shows the version number of the Adapter board I modified.
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Here is another ground test.
As TomC you said, this noise level is a little higher than average.
My opinion is that noise is high if you set the schema of probe cable as we told you. If you set the schema of probe cables "free" and straight, OK this is an average noise.
(sorry for my english...)
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The new PSU board and the modified Adapter board are in. In general, I'm disappointed with the performance of this upgrade.
Please can you take pictures from new adapter board (whole board) bottom and top side.
Same for new PSU board.
This picture what you now show about adapter board.....
I really think now that Owon want totally shoot down themselves.
I can not see on the adapter board any signs of Owon made needed modifications.
5.5V and TFT backlight SMPS circuits need redesign! There need only follow simplest rules for design low noise SMPS circuits. I have done lot of free work for Owon and send lot of documents how to do it.
(there need redesign PSU 8.4V and -7.6V, Adapter board TFT backlight, 5.5V and also 3.3V.
Also there is some other small things but they are not so acute - Example TFT databus)
And I can see they have not understood anything. (in this partial picture what TomC show)
I'm so angry now that it is better I do not write more...
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No rf-loop there is no any new adapter board.
They did only the psu board.
They suggest to TomC (probably, because they haven't any new redesign adapter board), to adds only the smd 1000pF (bypassing a specific capacitor). Absolutely, they need to modificate the adapter board.
I compared the new psu board (from TomC photos) with an older that upload somewhere at 60-66 pages at this forum. I devided the board to two parts, the left and the right one. The left is until to two optocouplers and include the Richtek 7731 PWM (smd), the right is at the rest.
As you can see there is no any modification at the left side. All the modifications was at the right side, they rerouted some paths, they applied more gnd plane and of course they used (as you very well suggest) a lot of decoupling capacitors (smd type). I measured 23 smd decoupling capacitors, almost. Additional they cut the connection of power switch (metal cage) with the gnd.
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Here is another ground test.
As TomC you said, this noise level is a little higher than average.
My opinion is that noise is high if you set the schema of probe cable as we told you. If you set the schema of probe cables "free" and straight, OK this is an average noise.
(sorry for my english...)
The negative clamp and the positive on the ground.
All equipement shut down. (I dont have much!)
Loose cable away from the screen.
So if I put ferrite, the noise should be lower than average?
;-)
JP
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If you put ferrites like TomC does, your sample noise gnd falling to 60-70mV (very good for my opinion). Don't forget to put and to battery cable (if you had battery as option).
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Just, I finished the study of TomC's captures and see the following:
1) the decoupling capacitor of 1000pF, decreasing the noise 5-10% almost. He had 143mV and falled to 120mV. Perhaps, Owon doesn't any ready for the new adapter boards and it suggests a smal impovement without a lot of mods.
2) they have done some works with psu board. Of course, they followed the rf-loop's suggestions and I think that it works!. If you see my post #1306 (ac without 2 ferrites inside, mod electrolytics_smd.png) with the related mods like Owon's, I had almost 68mV ground noise. If you see the TomC's post #1333 (Ferrites In sample mode.png) he had 56mV almost. If you see the TomC's results at post #1373 (Sample-new psu, mod adptr, no ferr.png), with the new psu board the noise is 74mV. All these results is unrelated from the initial noise level and provides same noise level with a small differences.
For me, the new psu board seems that has eliminate the noise that related from itself.
I understand that TomC has disappointed about this result, but he is at the right way. He is like running the half race. For me, must to wait for the next level of adapter improvement. The ferrites now can't to improve the noise, except the case that the probe's cable is positioned next to the TFT panel. I suggest to him, add a ferrite to battery ribon cable, also)
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Hi,
Did you meant Vp or Vk volts?
Joined: my last noise test. Moving the oscilloscope in the lab does not change the result.
JP
.
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172mVp-p is an average noise level with Acquire Mode to Peak Detect, but it is the best that you have measured.
If you set Acquire Mode to Sample, you are going to measure a range of 140-160mV.
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Look at these red arrows.
All these are decoupling smd capacitors that Owon adds to psu board for decreasing the noise level.
At the yellow one, they cutting the connection of power switch metal cage with the gnd (it was an antenna of radiation).
At the orange one, you see the rerouting of ground plane of board.
I think all these modifications was suggested to Owon from rf-loop member.
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Please can you take pictures from new adapter board (whole board) bottom and top side.
Same for new PSU board.
This picture what you now show about adapter board.....
I really think now that Owon want totally shoot down themselves.
I can not see on the adapter board any signs of Owon made needed modifications.
5.5V and TFT backlight SMPS circuits need redesign! There need only follow simplest rules for design low noise SMPS circuits. I have done lot of free work for Owon and send lot of documents how to do it.
(there need redesign PSU 8.4V and -7.6V, Adapter board TFT backlight, 5.5V and also 3.3V.
Also there is some other small things but they are not so acute - Example TFT databus)
And I can see they have not understood anything. (in this partial picture what TomC show)
I'm so angry now that it is better I do not write more...
rf-loop, the Adapter board pictures I posted are from my original adapter board with the modification Owon had me do as part of the upgrade. So apparently, the only difference in the adapter boards of the scopes now being produced is that additional 1000pF capacitor bypassing the 10µF electrolytic on top. I'm surprised about that too since you had quite a few more modification in version 2b of your DIY that Owon approved.
The pictures of the new PSU board and the little package containing power button caps and SMD capacitors are on post#1370. I can take pictures of the original PSU if you want to compare the two.
I'm also disappointed at Owon's decisions, they redesigned the PSU board and added a capacitor to the Adapter board, but their solution don't give as good results as what you did for free for them with your version 2b DIY. I wish they had paid more attention and at least compare the results and pick the best solution.
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I suggest to him, add a ferrite to battery ribon cable, also)
lemon, I don't have the battery option, that's why I didn't put a ferrite on the battery cable. However, I agree, that anybody that has the battery option would benefit from a ferrite on that cable. I didn't order the battery option because I don't need portability, I just use the scope around the house and there are AC outlets everywhere. If I need to do a floating ground test, I have an isolation transformer. Warning: Never use a scope for a floating test that is not specifically designed for this, the SDS7102 is not designed to do floating tests even if battery operated! Failure to heed this Warning can result in physical injury or death! However, I don't always do as I preach :=\
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What is a floting test?
JP
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If I need to do a floating ground test, I have an isolation transformer. Warning: Never use a scope for a floating test that is not specifically designed for this, the SDS7102 is not designed to do floating tests even if battery operated! Failure to heed this Warning can result in physical injury or death! However, I don't always do as I preach :=\
For the SDS Series, it's safe to “float” the “signal common” for making measurements provided you don't connect a signal greater than 30 VRMS (>42 Vpk) from earth ground to either the probe tip or common lead. For measurements where higher voltages {>30 VRMS, >42 Vpk) are present and running the DSO off the battery, the instrument’s chassis must be connected to earth ground using a grounding wire from the screw at the back of the DSO to prevent electrical shock to the operator.
If there's any doubt whether more than 30 VRMS is present or not, a grounding wire should always be used when running off the battery - and floating measurements SHOULD NOT BE ATTEMPTED! Be aware that hazardous voltages may exist in unexpected places due to faulty circuitry in the device-under-test.
(https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/?action=dlattach;attach=53818)
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What is a floting test?
JP
For example, you want to view the signal across a resistor, but neither end of the resistor is attached to ground. If you attach the scope's ground lead to either end of the resistor you effectively create a short to ground. One way around this, but strongly not recommended because of the danger involved, is to float the scope. For example, a battery operated scope can be used without plugging it into an AC outlet. Since in this case the scope's ground lead is not connected to earth ground, connecting it to the aforementioned resistor wouldn't cause a short. However, the scope's exposed metal parts are now at the same potential as the resistor's end where you attached the ground lead. If this happens to be a high enough voltage and you inadvertently touch a metal part of the scope, or if there is an insulation breakdown, you'll be lit up like a light bulb.
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I've run isolated CROs / DSOs for 20+ years. I have custom made mag shielded / filtered / line conditioner units with an available hard earth
connection if required. I have them set up in production areas as well. YES, you HAVE to be aware of possible dangers, but they are no
different to the days we had to work on 3-phase (415V) LIVE, or half the other dangerous stuff people have to do. It does NOT harm the CRO/DSO.
We often need to see AC current waveforms into capacitor banks and sometimes I connect across a 3 Phase 200VAC+ motor to check switching
noise and current waveforms. YES, you have to be AWARE and careful, but if you NEED to do it - DO IT.
Once it's isolated, touching ONE end doesn't give you a shock. Worst you feel, is a tiny "capacitance" or "rf" tingle - which reminds you it's there :-)
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I've run isolated CROs / DSOs for 20+ years. I have custom made mag shielded / filtered / line conditioner units with an available hard earth
connection if required. I have them set up in production areas as well. YES, you HAVE to be aware of possible dangers, but they are no
different to the days we had to work on 3-phase (415V) LIVE, or half the other dangerous stuff people have to do. It does NOT harm the CRO/DSO.
We often need to see AC current waveforms into capacitor banks and sometimes I connect across a 3 Phase 200VAC+ motor to check switching
noise and current waveforms. YES, you have to be AWARE and careful, but if you NEED to do it - DO IT.
Once it's isolated, touching ONE end doesn't give you a shock. Worst you feel, is a tiny "capacitance" or "rf" tingle - which reminds you it's there :-)
From Tektronix document on floating:
"This is dangerous, not only from the standpoint of elevated voltages present on the oscilloscope (a shock hazard to the operator), but also due to cumulative stresses on the oscilloscope’s power transformer insulation. This stress may not cause immediate failure, but may lead to future dangerous failures (a shock and fire hazard), even after returning the oscilloscope to properly grounded operation.
Not only is floating a ground-referenced oscilloscope dangerous, but the measurements are often inaccurate. This results from the total capacitance of the oscilloscope chassis being directly connected to the circuit under test at the point where the common lead is connected."
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I can't really disagree with anything that has been said here. In the past I also often worked with floating CROs, never had one fail as the Tektronix article states, even though every one of them was built by Tektronix. However, that doesn't mean it can't happen, after all, the manufacturer warns against doing it instead of claiming that it is a unique feature or capability. One may say that this is just a way to avoid liability, but in all probability they experienced failures while repeatedly testing their instruments under similar conditions. To me the main point is that floating scopes that are not specifically designed for this purpose can be very dangerous, even life threatening. So I wouldn't want to be the one that encourages someone that doesn't understand the risks or what they are doing to use this method. Yes, I have done it myself, but I was fully conscious of my actions and fearful enough of the risks to double check everything.
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Thanks to rf-loop's post I was able to convert to .csv. Here are the files renamed to .txt.
thanks TomC,
yeah, with GND was of course nonsense, i forgot that Owon is really switching to GND so lot of zeros inside csv.
I did FFT on the csv to check the if there is something visible from the sampling clock, it seems that the 250MHz image frequency is there.
Something is at 21.4MHz, and few third source signals between 75 and 86MHz as well.
(https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/?action=dlattach;attach=54084;image)
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Thanks tinhead for the fft results.
Your results is almost identical, with ones that we had to an unmodified SDS7102.
As you can you see at the 2:30 there is something at 80-90 MHz and 250MHz.
https://www.youtube.com/watch?feature=player_embedded&v=R5c1QNiBnQo#at=162 (https://www.youtube.com/watch?feature=player_embedded&v=R5c1QNiBnQo#at=162)
There was an older post of rf-loop, very interesting about two units of SDS7102 one without "ground noise" and other with it (post #1102).
https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/?action=dlattach;attach=47346;image (https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/?action=dlattach;attach=47346;image)
https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/?action=dlattach;attach=47348;image (https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/?action=dlattach;attach=47348;image)
At these two captures seems that the unit without noise there is no any 250MHz peak and of course has a low peak at the zone of 80-100MHz.
I think that will be very interesting if this fft test repeated with a new modified unit, as TomC's unit. TomC repeat this test and with low frequencies like 21.4MHz, please.
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I think that will be very interesting if this fft test repeated with a new modified unit, as TomC's unit. TomC repeat this test and with low frequencies like 21.4MHz, please.
I captured some FFT images. The first two are with the scope setup to view GND noise. The next three are with nothing connected to the BNC. In Run mode the signals are random and the capture don't really represent what you are looking for, like spikes at the 250MHz and vicinity of 25MHz.
So what I did is set the trigger to Normal for the GND noise images, and bring the level up until it no longer triggered, then back until it triggered once in a while. This way I could capture when the highest noise spikes were present.
For the images with nothing connected to the BNC there is not enough signal to trigger, so I had to use Single trigger mode and Force trigger until I got some images that showed the area of interest. But with the scope set to 5MHz/Div if you are in Auto trigger all you see is random, so I don't see anything significant in the 25MHz vicinity.
Now that I have a spare PSU, I've been examining it and trying to draw a better schematic than what they have on Version 1 of the Service Manual. The one thing that struck me as odd, so far, is that there isn't a bypass capacitor anywhere between either PSU ground plane and Frame ground. However, there is one between the two ground planes. I haven't checked to see if that's something that rf-loop added on his DIY version 2b. Let me know what you think.
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I see at the captures 1 & 3 (gnd noise & nothing to bnc) that the spike of 250MHz is smaller than before but is remaining. Interesting!
As I had told, I am in summer holidays and I can't try with my mod Owon.
I think that the 250MHz spike has a relation with the adapter board and perhaps explains why at rf-loop's captures is missing.
The pattern of spikes at range 80-100MHz, as you told, it isn't stable and there is no conclusions by static image.
At the old psu board, there is no any decoupling capacitors. These are added by rf-loop and this solution suggested to Owon.
As you can see at post #1383 there are a lot of them at yours board. The improvement of psu board has finished to my opinion.
If you have open the unit still, you can investigate the noise on specific area of adapter board.
This investigation method has analysed before from rf-loop (You must used two probes, the first one on Z-plate both tip and ground together, the second without ground clip and with protected tip - with the second probe approach all the specific areas) - sorry but I can't to explain better with this level of my english.
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250MHz peak come from ADC system. (this is proofed and it is exactly synch with ADC clock)
This peak can see also with Owon FFT.
(there is other peaks then what are related to several SMPS circuits but it os other story and these do not pollute signal pathway so much internally. This individual 250MHz peak (+ 500MHz) is there internally. But ... front panel read, this is 100MHz oscilloscope....
Interesting is that (many cases) if scope is cold and start up, then run FFT and look this peak. Note level. Then do fast power break, just off and immediately on. Many times this peak level drops. But if it is very low, then it may also in some cases rise). But this experience is with scopes what have used RuiFeng ADC when I have done more inspections. It is possible this is somehow related to ADC chip internal selfcal routines?)
(Run scope to warm, reboot.. sometimes it give small improvement for signal quality.)
Typically this peak have been well under -40...-50dB from 0dB (@1MHz) reference level (full scale) using 100mV range and FFT (10 dB scale) If I remember right. (Im out from work/workshop, can not now test. After some kind of partial summer holiday can do more )
(ADC have 4x250MHz datastream or better say 2 x 2 x 250MHz. Perhaps this is related to this peak. PCB topology is not best possible for isolate digital and analog sides.)
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rf-loop very interesting information.
As you said the peak of 250MHz is from ADC clock and this can't effect the operation of scope becouse it is a 100MHz scope.
As we know at the -3dB, BW is almost 200MHz (for units with version 2.4.1 and after) but this is under from 250MHz peak.
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Here in test image is visibble this self generated 250MHz "spurious" signal.
This image show how it is related to real signals in practical signal levels.
Scope Ch1 10mV/div
Signal adjusted so that using 1MHz this level give around full 10 divisions oscilloscope image.
Oscilloscope display infinite persistence.
Acquire mode normal.
FFT set for 1+dB/div and vertically adjusted bottom to bottom. Horizontally zoomed x2 and shifted 0 near left side.
First sweep from 1MHz to 360MHz
Then stopped and set for 107MHz.
(signal generator (HP8644B) level display -16.3dBm and this have measured that flatness is far better than specs limits) Around 34.24mV rms.
Botom part of image exatly same signal dropped 50dB to -66.3dBm (around 108uV)
(not in this image but 10dB less and still clearly detectable (34.24uV))
Impedance mathing is very poor, only 50ohm terminator with T so freq response suffer some amount about this.
250MHz (ADC circuit produced) spur is marked (also 500M 2. harmonic (and ADC base clock) is there but not in this image). Its level vary some amount due to base noise. (In this image it is more low than typical. This peak level also is different in different individual scopes. It may be even up to near this low cursor level. Specially in these cases fresh calibration may help and also power cycling "trick" after scope is warmed some minutes. Also there may be small differencies between RuiFeng or other brand ADC and scope manufacturing versions - these are so small things... )
If reader is not familiar with dB scales, it is good to realize what these images show.
50dB difference is roughly 1:320 voltage and 60dB means 1:1000 voltage ratio.
Oh - but it have 8 bit ADC.
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Here continue
Exactly same settings, signal dropped 10dB more.
Now 107MHz signal level is 34.2uV rms. (-76.3dBm) from HP8644B
Cable M17/84 and scope end T with 50 ohm terminator.
This signal is clearly detectable over noise floor.
Voltage is now 1/1000 from max level. (-60dB from ref level (1))
250MHz spurious level have now changed (it also vary due to noise floor, and may also change as temp in ADC circuit change. There is perhaps 20 minutes between these pictures due to signal level check with other equipments)
If Owon front end signal pathway is noisy, it really can't do this.
What under 0.5k$ chinese new scope can do this same in these images? I do not know, I have not yet seen any.
(and this is normal factory stock unit)
(1) ref level mean in this case:
Use oscilloscope mode and adjust 1MHz sine signal level so that peak to peak all is visible in TFT area (Owon TFT vertical area is around same as systen full scale)
In this case -16.3dBm signal give this level. (nearly 100mVpp in 50ohm system)
More high level start clipping and produce lot of "false" signals)
Changed to FFT and set upper cursor to this peak.
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Thanks rf-loop for all these information.
It is a pitty such hw to have so basic fw.
All we know that the fw is stable but doing only the basics.
At post #1285 we had including our observations about fw and what we want to changed. I have sent this list to Owon (info@...) but I have no any respond until now.
The Owon is the smalest company of all Chinesse companies that make oscilloscope, with good results on hw but they have a weakness to make a good fw.
At the last two year from SDS Series introduction, they've done very little extra work in the FW department (I know they fixed some bugs, of course).
Perharps the department of research and development of fw doing their best, perhaps they know that sold a cheap oscilloscope (under 0.5K$) with a well made of hw but basic fw and they wouldn;t to nothing at all.
I know rf-loop that you have some contact with them often. Do you have any information about how they think to development the fw?
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I did FFT on the csv to check the if there is something visible from the sampling clock, it seems that the 250MHz image frequency is there.
Something is at 21.4MHz, and few third source signals between 75 and 86MHz as well.
i should probably mention that the only reason i asked for csv was to see if there are any spurious when in lower timeabse (that works on most DSOs, here the firmware will not filter anything). Normally the firmware will anyway filter that 250MHz (and in 8/9xxx Owons that will be 500MHz signal) and on the other side it is above the DSO bandwidth, so not an issue at all.
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This is a video that was given to me by Owon tech support when they shipped the new PSU for my SDS7102. It shows how to completely teardown an SDS scope in about 5 minutes. I asked them if they could upload to YouTube and they said there was no access to YouTube in China but that it was OK for me to upload it. So it's now in my channel (TomC3106), only video there so far.
The only thing you have to watch for that I don't see in this video is what to do about the power button. So be careful and make sure that you push in the power button while removing the cabinet. On older scopes it was possible to remove the power button cap with pliers beforehand, but in my scope this was not possible because the cap has two plastic protrusions that catch under the cabinet hole. However, on the new power button caps that they sent me these protrusions have been cut off. So it's possible that the latest scopes are shipped with these modified power button caps.
SDS Teardown (https://www.youtube.com/watch?v=Zct3Ircz6nY#)
I also asked Owon if there were any plans to implement additional modifications on the Adapter board to further reduce the GND noise. The response is that for now there are no plans for further changes.
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Just a note: The older power caps (mine is from early 2012) also seem to have the protrusions cut off. There are visible marks where they used to be.
Also I wouldn't recommend numerous dis assemblies of the scope, because the screw posts can wear out relatively quickly.
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Thanks for sharing TomC,
It's really! The youtube is forbidden to the people of China.
Please look if you have add metadata (or keywords) to youtube metadata search (like: Owon, SDS, 7102, teardown, disassemble e.t.c).
From what I have seen this video isn't easy searchable to youtube.
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Thanks for sharing TomC,
It's really! The youtube is forbidden to the people of China.
Please look if you have add metadata (or keywords) to youtube metadata search (like: Owon, SDS, 7102, teardown, disassemble e.t.c).
From what I have seen this video isn't easy searchable to youtube.
Thanks for the tip Lemon,
I added some more tags as you recommended, so hopefully the video is easier to find now.
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I received the new PSU board. After I opened the case, I noticed my adapter board is different (see the picture below). What should I do?
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It looks pretty much like my adapter board.
The safest and perhaps most obvious solution would be to ask Owon and let us know what they answer. This board does not have the affected capacitor as a through-hole component (or at all, I'm not 100% sure at the moment), as far as I can see. On the other hand, maybe there are some other "easy" modifications that can be done on it to improve performance.
If I remember correctly, that Russian guy (whose username I can't remember) had similar board and made some modifications to it. That was maybe 6-8 months ago and was a bit more complex than adding a single ceramic capacitor.
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I received the new PSU board. After I opened the case, I noticed my adapter board is different (see the picture below). What should I do?
mlhstock,
I looked at one of your previous posts and it states that your scope's serial number is 1303xxx. This means that your scope was built on the 3rd week of 2013. Now here is the puzzling thing, my scope's serial number is 1246xxx, meaning that it was built on the 46th week of 2012, yet, my adapter board is version 3.2. Now, how is it possible that your scope, which was built around 2 months later, has a version 3.0 adapter board. I don't want to speculate, but it gives me an uneasy feeling that there is a possibility that the adapter board in your scope is not the original one. I would very carefully check the scope for any additional telltale signs that may lead you to believe that it may have been altered or refurbished by the dealer before it was shipped to you.
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In some cases some older version may be better than some later version.
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I received the new PSU board. After I opened the case, I noticed my adapter board is different (see the picture below). What should I do?
You're not alone. The design of version 3.0 is crap, continuous gnd plane cuts, parallel capacitors that resonate at frequencies where noise is generated, DC / DC Boost with input connected to critical places (everyone should know that at the input is where more noise is generating by a boost), etc.
I tried to explain to OWON that for those who have the 3.0 version a 1n capacitor is not enough, but there is no way. :palm:
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It looks pretty much like my adapter board.
The safest and perhaps most obvious solution would be to ask Owon and let us know what they answer. This board does not have the affected capacitor as a through-hole component (or at all, I'm not 100% sure at the moment), as far as I can see. On the other hand, maybe there are some other "easy" modifications that can be done on it to improve performance.
If I remember correctly, that Russian guy (whose username I can't remember) had similar board and made some modifications to it. That was maybe 6-8 months ago and was a bit more complex than adding a single ceramic capacitor.
Siri was.
Page 62.
It is better to see the rf-loop's mod (version 2b) from Electronics and Owon SmartDS oscilloscopes Forum (http://owon.forumup.com/ (http://owon.forumup.com/)) but all these mods demands tools and very well smd soldering knowledge.
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It is better to see the rf-loop's mod (version 2b) from Electronics and Owon SmartDS oscilloscopes Forum (http://owon.forumup.com/ (http://owon.forumup.com/)) but all these mods demands tools and very well smd soldering knowledge.
Sure?
This modification version 2b, for all I know can use directly for 3.2 adapter board and directly or nearly directly for 3.1 adapter board, only.
Cheers!
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Thank you all the guys for starting and keeping this thread!
Below is my experience with "GND noise" mods for V3.0 adapter.
I am also owner of SDS7102. My SDS has OWON's manufacturing date code: 1223.
PSU is PCB-T115-J Rev6. Adapter is CONNECT_V3.0
My original Vp was aprox. 180-210mv.
I've applied DIY mod 2b designed by honoured rf-loop
with necessary alterations for T115-J Rev.6 PSU's and V3.0 adapter's PCB layout.
Upon application of mod 2b for PSU I've got positive effect.
Application of mod 2b for V3.0 adapter probably also had lowered the noise a little bit but not sufficient enough.
At this moment the Vp that I have is 80-90mV, so it still needs improvement.
V3.0 produces TFT LED back light voltage using 5.5V as a source.
V3.2 takes +8.4V from PSU as a source.
This difference affects schematics and PCB routing as well.
I've reviewed this thread and found out two cases of "GND noise" work over V3.0:
- first one was made by the forum member with logname EU1 started at page 45 message Id #664
and finished at page 47 #701 with resolution:
Resolved by adding an inductor on 5.4V rail as it was proposed by OWON.
- second one was made by the forum member with logname Siri (he had V3.0) aprox. at page 62
with resolution at page 65 #971
I wonder how you managed so well to reduce noise backlight?
Next was the question from the forum member alexuresp (#972):
Now the main noise from LCD. rf-loop how you fight with this ?
I found no answer on this question.
So it looks like that DIY solution on how to reduce noise on V3.0 adapter is yet not fully disclosed at this time.
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mlhstock,
I looked at one of your previous posts and it states that your scope's serial number is 1303xxx. This means that your scope was built on the 3rd week of 2013. Now here is the puzzling thing, my scope's serial number is 1246xxx, meaning that it was built on the 46th week of 2012, yet, my adapter board is version 3.2. Now, how is it possible that your scope, which was built around 2 months later, has a version 3.0 adapter board. I don't want to speculate, but it gives me an uneasy feeling that there is a possibility that the adapter board in your scope is not the original one. I would very carefully check the scope for any additional telltale signs that may lead you to believe that it may have been altered or refurbished by the dealer before it was shipped to you.
TomC,
I have the same doubt, but I couldn't find any trace of repairing. The dealer told me the scope was shipped directly from the warehouse. Anyway, I asked for a refund or exchange and the dealer is waiting for the response from Owon before he sends me a new version scope. The non-sense adapter card version is one of reasons why I ask for exchange. Another reason is because I noticed the fan is quite noisy. I think people commented that the fan noise should be hardly inaudible, but mine is as loud as my very old Tektronix analog oscilloscope.
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TomC,
I have the same doubt, but I couldn't find any trace of repairing. The dealer told me the scope was shipped directly from the warehouse. Anyway, I asked for a refund or exchange and the dealer is waiting for the response from Owon before he sends me a new version scope. The non-sense adapter card version is one of reasons why I ask for exchange. Another reason is because I noticed the fan is quite noisy. I think people commented that the fan noise should be hardly inaudible, but mine is as loud as my very old Tektronix analog oscilloscope.
Good for you! Hope they do the right thing and agree to give you the latest version scope they promised you in the first place. As for the fan, I have several older Tektronix scopes and the fan on my SDS7102 is quieter than everyone of them.
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I got reply from my dealer and Owon denies there're multiple versions of adapter boards, here's the quote from dealer's email
we got reply from manufacturer, they said there is no old generation for adapter board, they only have one version
I am really pissed off by Owon's response and ask my dealer give me the full refund, no more exchange. If Owon lied about the adapter board, how can I trust them that they will keep 3-year warranty promise? I don't want to have business with a liar even the oscilloscope has a good price/performance ratio.
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I am really pissed off by Owon's response and ask my dealer give me the full refund, no more exchange. If Owon lied about the adapter board, how can I trust them that they will keep 3-year warranty promise? I don't want to have business with a liar even the oscilloscope has a good price/performance ratio.
Honestly, I think it's laughing at us, Owon given me a different answer every time.
"I don't want to have business with a liar." Neither I.
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I got reply from my dealer and Owon denies there're multiple versions of adapter boards, here's the quote from dealer's email
we got reply from manufacturer, they said there is no old generation for adapter board, they only have one version
I am really pissed off by Owon's response and ask my dealer give me the full refund, no more exchange. If Owon lied about the adapter board, how can I trust them that they will keep 3-year warranty promise? I don't want to have business with a liar even the oscilloscope has a good price/performance ratio.
It's a shame that they are pointing fingers at each other, can't get much resolved in that state of mind. The dealer says the scope came directly from the warehouse, Owon says there is only one version of adapter boards. Perhaps they are both telling the truth but overlooking the obvious. Owon can't possibly mean that the same adapter board version has been used ever since the SDS series was released, it's too much of a fib even for the best poker faced liar, tons of evidence on the internet to debunk that in two seconds. But if what they mean is that only one version was used on scopes built during 2013, that would be much more credible. The dealer may not have changed the board, after all, he just had the scope drop shipped from a warehouse somewhere. What is not known, is what happened at the warehouse. For example, stocking returns as brand new products is not an unheard of sleazy practice.
In any case, you are probably better of getting your money back. It seems that your dealer is not willing to take some responsibility for what happened and is pulling every trick in the book to keep his profit intact. If you decide to try again for an SDS scope I would definitely use a different dealer. Good Luck!
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But if what they mean is that only one version was used on scopes built during 2013, that would be much more credible.
It seems still have problem to explain the strange combination: S/N 1303xxx, Ver3.0 adapter board inside and an instruction of adding 1000pF capacitor for Version 3.2 adapter board. Whatever. I will fight for my money back.
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It seems still have problem to explain the strange combination: S/N 1303xxx, Ver3.0 adapter board inside .......
Is it SDS7102V ?
This is really strange. I have lot of documents about S/N 71021303xxx
(SDS7102V)
Something is very strange if there is V3.0 adapter board inside and it is S/N71021303xxx serial.
Is this unit really left from original Owon factory as it is now.
I can not proof it of course - all is possible.
But in this point now, without more data it feels like someone lie.
Btw, is there scope back, scope carton AND scope also display exactly same serial number?
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It need also note that I have personally seen also that inside same version adapter board (example SDS7102_CON_3.2) there may be small differencies. Perhaps some times after changes someone have forget update also print mask.)
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Btw, about communication with chinese.
Try small example.
Write your letter as you do it but just before send, copy paste it to example google translator and translate it to chinese. After then, copy paste this translation agen to google translator and translate this chinese letter to english. Now, how you answer this letter?
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Bit modified/simplified/imagined old case with Owon:
I: I need spare part. I need adapter board version 3.2 for SDS7102V....
O: What is adapter board?
I: it is board between PSU and main board...
O: What you mean about adapter board, no need adapter board, please send picture what you want...
I: here is picture (picture including board version)
O: Ok, we can send it to you.
later...
I get exactly this board what was in my picture. I think if they copy my picture and made it....hahah)
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..... and an instruction of adding 1000pF capacitor for Version 3.2 adapter board.
Who and where have give this instruction: Owon?
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..... and an instruction of adding 1000pF capacitor for Version 3.2 adapter board.
Who and where have give this instruction: Owon?
Yes, this instruction is from Owon.
TomC, had this instruction from Owon, when he received the new psu board. There was a video how to change the new psu and some instruction how to add this smd capacitor to the 3.2 adapter board between the legs of electrolytic capacitor.
Probably, they believes that the combination of new psu and smd capacitor adding is decreasing the noise at the well level for 2013 versions.
TomC asked them if they are going to produce new adapter version. Their answer was no for this time.
For the mlhstock's situation, I believe that there was a third person between Owon factory and dealer. Probably the dealer bought the scope not directly from Owon factory but from someone Chinesse person.
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Thank you all the guys for starting and keeping this thread!
Below is my experience with "GND noise" mods for V3.0 adapter.
I am also owner of SDS7102. My SDS has OWON's manufacturing date code: 1223.
PSU is PCB-T115-J Rev6. Adapter is CONNECT_V3.0
My original Vp was aprox. 180-210mv.
I've applied DIY mod 2b designed by honoured rf-loop
with necessary alterations for T115-J Rev.6 PSU's and V3.0 adapter's PCB layout.
Upon application of mod 2b for PSU I've got positive effect.
Application of mod 2b for V3.0 adapter probably also had lowered the noise a little bit but not sufficient enough.
At this moment the Vp that I have is 80-90mV, so it still needs improvement.
V3.0 produces TFT LED back light voltage using 5.5V as a source.
V3.2 takes +8.4V from PSU as a source.
This difference affects schematics and PCB routing as well.
I've reviewed this thread and found out two cases of "GND noise" work over V3.0:
- first one was made by the forum member with logname EU1 started at page 45 message Id #664
and finished at page 47 #701 with resolution:
Resolved by adding an inductor on 5.4V rail as it was proposed by OWON.
- second one was made by the forum member with logname Siri (he had V3.0) aprox. at page 62
with resolution at page 65 #971
I wonder how you managed so well to reduce noise backlight?
Next was the question from the forum member alexuresp (#972):
Now the main noise from LCD. rf-loop how you fight with this ?
I found no answer on this question.
So it looks like that DIY solution on how to reduce noise on V3.0 adapter is yet not fully disclosed at this time.
Very usefull summarise, I supposed.
kptn we have the same adapter version.
As you can see at my previous messages, I have make same mods like you to my psu and adapter board.
I would like to ask you some things.
What value of inductor you add to 5.4 rail? My scope has this adding from factory but this adding was by hand. It is an after production adding with few words. My this inductor value is 10mH but I have measured this only 3.2mH. I am thinking to change this with an other with 10mH value. It is at the same position as Siri's photo present (the inductor under the ribbon cable)
(http://img-fotki.yandex.ru/get/6447/200130167.0/0_afd5b_6af6f6c7_L.jpg).
At the last I would ask you if you can upload a photo from the upper of your adapter board.
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..... and an instruction of adding 1000pF capacitor for Version 3.2 adapter board.
Who and where have give this instruction: Owon?
Yes, this instruction is from Owon.
TomC, had this instruction from Owon, when he received the new psu board. There was a video how to change the new psu and some instruction how to add this smd capacitor to the 3.2 adapter board between the legs of electrolytic capacitor.
Probably, they believes that the combination of new psu and smd capacitor adding is decreasing the noise at the well level for 2013 versions.
This one capacitor do not reduce common mode noise what is produced by TFT LED SMPS. And there is also 5.5V SMPS circuit (this have high noise) and 3.3V SMPS (this is not so noisy). This capacitor only filter small amount of output RF noise to LED's from backlight SMPS circuit.
It is very pity they do not want understand this whole case.
I have told that filtering some bad SMPS circuit output do not solve this issue. They do not understand how this GND "pollution" works.
Only solution for good result is design (I mean real design including test redesign iterations) totally new low EMI PSU and totally new low EMI Adapter board. Including also redesign for TFT databus. These need redesign just from scratch. First delete everything from old boards.
It need do only once. It need only one good design, no need then make frequently small changes after changes.
If they continue this road what they now use... they destroy themselves.
But this "captain of Titanic" do not listen anybody.
No one can not force them to do right things.
Money can perhaps teach, but this lesson is perhaps coming too late if they want rescue themselves. They should be wise in advance.
They have now loosed nearly half year and lot of customers. And still this stupidity continue.
If they do not now, just least immediately now, turn they course it may lead to crash and there is no road to back.
Still I wonder why we have Owon scopes in stock, and I'm personally absolutely sure they are directly from original Owon factory product line and they do not have this level of this issue.
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(http://img-fotki.yandex.ru/get/6447/200130167.0/0_afd5b_6af6f6c7_L.jpg).
[/quote]
What version read exactly on this adater board. (this board is (Owon) modified board from some version)
Only case I have seen this board is in one "siri" picture. Never seen this version live in my hand. (also this board may have totally different backlight SMPS circuit than V3.2)
(I wonder how many versions and modified sub versions they have without change in version number)
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V3.0 is the same as mine. It came with a motherboard of mid-2012.
Obviously, this is modified for me. That cut in the ground plane (RED) is critical. And C44, 45 and 36 resonate at noise frequencies, better remove C36.
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Exactly, version 3.0
An other photo from version 3.0 (from post #928, page 62, Siri's adapter photo), Adapter board: SDS7102_CON_V3.0 (2011.11.14)
It appears the adding inductor at the rail of 5.4V.
(http://img-fotki.yandex.ru/get/5633/200130167.0/0_afc35_1b15ddc_L.jpg)
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Yes, that shows that they knew the noise problem, and tried to correct it with that inductor, as a filter.
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Exactly, version 3.0
An other photo from version 3.0 (from post #928, page 62, Siri's adapter photo), Adapter board: SDS7102_CON_V3.0 (2011.11.14)
It appears the adding inductor at the rail of 5.4V.
(http://img-fotki.yandex.ru/get/5633/200130167.0/0_afc35_1b15ddc_L.jpg)
Who designed this? He was drunk? I'll post more pictures from other tinkering that I have found. Sorry wanted to say botched (made by OWON), not tinkering.
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Of course they knew about ground issue but if I remember right this inductor adding wasn't for decrease the ground noise but for lcd noise about.
Carrington I see some modification at your board. I have adding some arrows at various areas. Can you give us the information what you have done?
1) you have removed the factory inductor and you put two other smd inductors (what value) and one smd decoupling capacitor...
2) you removed the electrolytic and a smd ceramic capacitor and....
3) probably you have add a decoupling capacitor...
4) you have removed the U13 chip...
5) ??
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Of course the knew about ground issue but if I remember right this inductor adding wasn't for decrease the ground noise but for lcd noise about.
Carrington I see some modification at your board. I have adding some arrows at various areas. Can you give us the information what you have done?
1) you have removed the factory inductor and you put two other smd inductors (what value) and one smd decoupling capacitor...
2) you removed the electrolytic and a smd ceramic capacitor and....
3) probably you have add a decoupling capacitor...
4) you have removed the U13 chip...
5) ??
1) you have removed the factory inductor and you put two other smd inductors (what value) and one smd decoupling capacitor...
Several testing to determine the source of the noise.
Yes, by a ferritebead and a 10uF ceramic capacitor. Sorry, I do not know what kind of ferritebead is, but very low DC R.
2) you removed the electrolytic and a smd ceramic capacitor and....
I get a attenuation of the HF noise.
3) probably you have add a decoupling capacitor...
Yes 10uF, and another ferrritebead. (-7V)
4) you have removed the U13 chip...
Several testing to determine the source of the noise. I used another 5V source. Really was ~5V6 of a DC Battery.
5) ??
I check the variations of the noise, changing the ground plane cuts.
This modifications are only a test. :)
It's a shame, but due to the indifference of the manufacturer for months, many of us have had to modify it by necessity. Now OWON modifies the PSU, but not the adapter, which is another source of noise, rfloop indicated the need to modify this too, I think.
Another test on the PSU, see the picture. The effect is similar to put a ferrite in the cable of the PSU.
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Thanks for the quick reply.
I think that the mods to psu board has finished, after the rf-loop's nice work. The new board of Owon (like TomC has saw us) applies all these changes. If you see how they adding all the smd decoupling capacitors, you have the answer how to doing to yours psu board.
The adaptor board wants more investigation for improvement. We have rf-loop's work again (to 3.2 versions), we have the Siri's observations (the nice turning of diode) for version 3.0 and we wants more investigation to the same directions.
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Unfortunately, many of us can not afford to pay more, and this oscilloscope seems to be the solution, but it turns out to be a problem. :--
Anyone know if this is a later/previous version of the SDS?
Wow 800€!
http://www.reichelt.de/Oscilloscopes-Spectrum-Analyser/PEAKTECH-1260/3/index.html?;ACTION=3;LA=2;ARTICLE=113054;GROUPID=4044;artnr=PEAKTECH+1260 (http://www.reichelt.de/Oscilloscopes-Spectrum-Analyser/PEAKTECH-1260/3/index.html?;ACTION=3;LA=2;ARTICLE=113054;GROUPID=4044;artnr=PEAKTECH+1260)
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It is a clone oscilloscope by PeakTech Company.
From what I saw at the links http://www.peaktech.rce.it/index.php?main_page=product_info&cPath=79_81&products_id=350 (http://www.peaktech.rce.it/index.php?main_page=product_info&cPath=79_81&products_id=350)
http://www.peaktech.de/productdetail/kategorie/digital-oszilloskope/produkt/peaktech-1245.857.html (http://www.peaktech.de/productdetail/kategorie/digital-oszilloskope/produkt/peaktech-1245.857.html)
it is a clone of SDS7102V with the same firmware! They have the same series like Owon!
It is very strange that they have the same fw. What hell is going there? Who is made the fw, finally?
(http://www.peaktech.rce.it/images/large/1255_LRG.jpg)
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Made by Owon.
They can do it with your own boot up image and front panel logo.
If you want sell these with KingKong name, just draw your logo etc and pay.
With Aktakom name these have been long time.
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Well, now know two brands more that we should not buy because they are also rubbish. Thanks rf-loop. ;)
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It is very strange that they have the same fw. What hell is going there? Who is made the fw, finally?
I believe it's made by Owon, however, I found a small difference on the firmware on page 105 of the PeakTech manual. The probe menu doesn't have the current option.
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I just found a new version of the Oscilloscope software at the Owon site (2.0.8.17). The only difference I found so far is a new "SCPI Command Line" button on the Remote Control Panel. However, when you try to use it emits an error message "SCPI is not support for the machine". SCPI (Standard Commands for Programmable Instruments) is widely used by other test equipment manufacturers.
I also checked the LAN interface to see if they had fixed any of the long standing problems, but no luck. Image transfer doesn't work and High Memory Depth still causes the scope to freeze if the Acquire Length is 10M.
Edit: Just noticed the splash screen and About screen are also different, they show DS-WAVE instead of Owon.
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The attachment is a preliminary schematic of my original PSU (PCB-T115-N rev 3) that I've been working on for the last few days. Since I now have a new PSU I'm planning to do some modifications on the original PSU and I thought a schematic may help me better understand what I'm doing. I haven't double checked this so there may be some errors or omissions, please let me know if any are detected.
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Very nice and precisely work! Well done TomC, thanks for that (bravo :-+ ).
From what I have seen at the new yours psu board (optical comparison) there are some new reroute paths and a lot of decoupling capacitors.
Unfortunately, I don't expect a significant improvement in software of this oscilloscope.
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How many amperes must to be the 10mH smd inductor of line 5.4V?
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How many amperes must to be the 10mH smd inductor of line 5.4V?
I don't know that there is an SMD inductor. If you are talking about the battery charging circuit, I know that there is a current sense circuit in the feedback loop (IC2C monitors the voltage drop across R14, R14A, R14B), so the charge current will be limited by this. However, I haven't investigated what the exact value is yet. There is also an overcurrent circuit built into the battery pack's PCM circuit. I'm currently working on a theory of operation paper for the entire PSU, I'll post what I have when I make a little more progress.
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How many amperes must to be the 10mH smd inductor of line 5.4V?
If is this (marked in red), look at the datasheet of the AOZ1094 (Alpha & Omega), but 3A for sure. And SMD mark is: 100 -> 10uH
Wow 5A at least. http://www.coilcraft.com/mss1278.cfm (http://www.coilcraft.com/mss1278.cfm)
Another thing: In the 3.0 version the LCD power is a AT1780 (Aimtrom). Vin = 6V (Max)
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I know that there is a current sense circuit in the feedback loop (IC2C monitors the voltage drop across R14, R14A, R14B), so the charge current will be limited by this. However, I haven't investigated what the exact value is yet. There is also an overcurrent circuit built into the battery pack's PCM circuit.
The current sense circuit is set to limit the supply's output current to about 3.75A, the PCM circuit kicks in if the charge current reaches about 5A and cuts-off the cell connection. This should never happen if the 8.4V supply is working properly. When the output current is below 3.75A, the voltage sense circuit keeps the supply's output at 8.4V.
While researching this answer I discovered that R13, R13A, R13B, R14, R14A, and R14B are mislabeled, they should be 0.1 ohm instead of 1 ohm. Because of this the notes next to R13A are also incorrect. It's a work in progress, so there are bound to be more errors. I'll post a corrected schematic after I do a little more debugging. In the mean time, any member that is interested, please let me know about any other detected errors, or about anything that doesn't make sense.
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Is it SDS7102V ?
This is really strange. I have lot of documents about S/N 71021303xxx
(SDS7102V)
Something is very strange if there is V3.0 adapter board inside and it is S/N71021303xxx serial.
Is this unit really left from original Owon factory as it is now.
I can not proof it of course - all is possible.
But in this point now, without more data it feels like someone lie.
Btw, is there scope back, scope carton AND scope also display exactly same serial number?
Yes, it is SDS7102V (with VGA and Ethernet options). The dealer said they didn't do any work on the scope and it was from manufacturer. All three serial numbers are the same.
My dealer and Owon agree that I can return it. They already gave me RMA# so I will send it back soon.
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@mlhstock = well done!
@ TomC = I don't meant the psu board but the adapter board (version 3.0). Keep your good work!
@ Carrington = Yes, this is that I meant, the inductor in your red cycle (I have an adapter version 3.0). It writes 100 = 10mH but I measured this with value of 3.2mH and I want to change it.
For 5.0A what you thinking about:
http://www.ebay.co.uk/itm/271241147874?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649 (http://www.ebay.co.uk/itm/271241147874?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649)
or with limit of 4.8A the:
http://www.ebay.co.uk/itm/390565310228?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649 (http://www.ebay.co.uk/itm/390565310228?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649)
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Yes, it is SDS7102V (with VGA and Ethernet options). The dealer said they didn't do any work on the scope and it was from manufacturer. All three serial numbers are the same.
My dealer and Owon agree that I can return it. They already gave me RMA# so I will send it back soon.
You were lucky!
I was not so lucky.
OWON = No serious people.
Moreover, they are as false as his instruments specifications, by omission or noncompliance.
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It writes 100 = 10mH but I measured this with value of 3.2mH and I want to change it.
100 = 10uH
Examples:
http://www.alliedelec.com/search/productdetail.aspx?SKU=70153506 (http://www.alliedelec.com/search/productdetail.aspx?SKU=70153506)
http://www.alliedelec.com/search/productdetail.aspx?SKU=70068704 (http://www.alliedelec.com/search/productdetail.aspx?SKU=70068704)
OR
103 = 10uH
Examples:
http://www.alliedelec.com/images/products/datasheets/bm/DELEVAN_API/70033237.pdf (http://www.alliedelec.com/images/products/datasheets/bm/DELEVAN_API/70033237.pdf)
If its value is 3.2uH then is broken. Burned/Scorched...
But I'm not surprised, mine came with an inductance with half coating. That's nothing to what I've seen. :palm:
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You've right!
100 = 10uH
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Lemon make only two changes:
1º remove C36.
2º make a bridge, as the red square (don´t short it with feedback to R21).
Note: Do not remove C44.
The noise should go down, because you eliminate resonances.
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Thanks Carrington for these suggestions.
I have applied some rf-loop's mods from ver.3.2 already, but I'll apply your suggestion at the end of my holidays (in 10 days).
My noise, after psu and adaptor mods (see at post #1307, page 88) ) is almost 48-64mVp-p (Sample Measurement) or 60-70mVp-p (Peak measurement).
I would to investigate the effectes of inductor in line of 5.4V to noise and how is related with various values.
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Look at these red arrows.
All these are decoupling smd capacitors that Owon adds to psu board for decreasing the noise level.
At the yellow one, they cutting the connection of power switch metal cage with the gnd (it was an antenna of radiation).
At the orange one, you see the rerouting of ground plane of board.
I think all these modifications was suggested to Owon from rf-loop member.
(https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/?action=dlattach;attach=53796)
TomC, can you measure these smd decoupling capacitors? What value have they?
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TomC, can you measure these smd decoupling capacitors? What value have they?
I don't have the scope apart right now, however, I will be taking it apart when I finish modifications on the old power supply and put it in. I'll make a schematic of the new PSU then and measure all these new components and compare it in detail to rf-loop's DIY. From what I've seen so far, Owon followed rf-loop's version 2b DIY for their new PSU design, so these capacitors are probably what rf-loop recommended, mostly 220nF. Hope you are having fun on your holiday!
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Greetings from Russia!!! I became the owner of this wonderful device sds7102v.....And here are my results...
(http://)
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(http://)(http://)
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(http://)
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(http://)
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My rework - transferred power sources 5.5V, 3.3V and screen backlight on separate charges. And added filters on nutrition.
Very much noisy display. Did it on a separate Board (DC-DC for Led). And moved to the edge of the LCD screen. Now there remain only "digital" noise....I think they signals from the screen. I'll try to play around with resistors.
Sorry for such a English... ;)
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My rework - transferred power sources 5.5V, 3.3V and screen backlight on separate charges. And added filters on nutrition.
Very much noisy display. Did it on a separate Board (DC-DC for Led). And moved to the edge of the LCD screen. Now there remain only "digital" noise....I think they signals from the screen. I'll try to play around with resistors.
Sorry for such a English... ;)
Those are great results! Can you give us some more specifics on the modifications you performed? Like pictures of boards, component values, etc.
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TomC, can you measure these smd decoupling capacitors? What value have they?
I don't have the scope apart right now, however, I will be taking it apart when I finish modifications on the old power supply and put it in. I'll make a schematic of the new PSU then and measure all these new components and compare it in detail to rf-loop's DIY. From what I've seen so far, Owon followed rf-loop's version 2b DIY for their new PSU design, so these capacitors are probably what rf-loop recommended, mostly 220nF. Hope you are having fun on your holiday!
OK TomC take your time.
Yes, it is probably they followed the rf-loop's directions.
@ BBAAHHOO = Hi Russia, you had great results!
From what I have undertand you used individual power sources for 5.5V, 3.3V and lcd backlight.
As TomC said, can you give us more information about these mods?
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(http://)
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A strong effect of filters. The LCD screen connected body with the Earth, and transfer the backlight inverter. Ordinary SMD capacitors on 0.1 (http://)
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(http://)
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(http://)
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(http://)
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(http://)
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(http://)
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While I'm at it and will comment ...can anyone else what ideas may lay? ;)
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While I'm at it and will comment ...can anyone else what ideas may lay? ;)
There have been many ideas posted in this thread, but I haven't seen any with so many extra components as your mods. From what I understand from your schematic, you have added common mode chokes, inductors, and capacitors to filter the noise, but are still using the original DC/DC PWM converters. Is this right?
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Yes, all native. added filter only. Now only makes noise from power supply (AC-DC), and the visible digital noise (or memory or LCD screen).
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Yes TomC, from what I see from the schematics and photos the "BBAAHHOO" uses the original main psu board with a lot of mods. He has removed some dc-dc chips at adapter board, because he gives individual volts to this adapter.
He has applied the most deeper mods that I have seen, but we don't know what versions are the main psu board and adapter board, please BBAAHHOO give us this information.
BBAAHHOO, you have achieve the lowest measurement (I think it is same like rf-loop) at this thread.
Please for comparison reasons, repeat the test of noise ground as decribed at post #1330, page 89 and give us the Vp-p value and the capture.
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Please for comparison reasons, repeat the test of noise ground as decribed at post #1330, page 89 and give us the Vp-p value and the capture.
More about:
The "Mainboard" also have a DC/DC connected to ~5.54V it generate noise that goes to the analog power of the input stage. This DC/DC supply power to the entire DAC. :palm:
Below the shielding metal sheets of the input stage there is a 5V LDO, connected to ~5.54V (i.e Vdo <0.54). And if Owon did not put any filters (F.Bead) in the input of the analog power for the DAC, less to the input of the analog power for the input stage. This LDO is able to reject only some frequencies <1MHz. Similar for the 7905.
Yes, please for comparison reasons, repeat the test of noise ground as decribed at post #1330, page 89 and give us the Vp-p value and the capture.
More:
- To correct variations between channel 1 and 2 in some oscilloscopes Owon add extra resistors there where Owon think. :palm:
- The 5V regulator thermally affects more the channel 1, since it is closer, this explains its greater DC drift. :palm:
Now I do not think Owon would like to save money, rather it seems that, did not even know how to make the oscilloscope.
Well done Owon... This is not an oscilloscope, is shit. :--
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Carrington for your observations I'll wait for the rf-loop's answer, becouse he knows this unit very well.
But as we know this oscilloscope has no any noise at front end level.
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Carrington for your observations I'll wait for the rf-loop's answer, becouse he knows this unit very well.
But as we know this oscilloscope has no any noise at front end level.
Lemon, do You think that rf-loop will throw stones at his own roof?
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#1330, page 89 and give us the Vp-p value and the capture.
Batarey
(http://)
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(http://)
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If I see well 28-30mVp-p, many thanks for the captures :-+
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Carrington for your observations I'll wait for the rf-loop's answer, becouse he knows this unit very well.
But as we know this oscilloscope has no any noise at front end level.
Lemon, do You think that rf-loop will throw stones at his own roof?
Carrington I don't know but we can waiting about rf-loop's answering about these issues.
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TomC, can you measure these smd decoupling capacitors? What value have they?
I don't have the scope apart right now, however, I will be taking it apart when I finish modifications on the old power supply and put it in. I'll make a schematic of the new PSU then and measure all these new components and compare it in detail to rf-loop's DIY. From what I've seen so far, Owon followed rf-loop's version 2b DIY for their new PSU design, so these capacitors are probably what rf-loop recommended, mostly 220nF. Hope you are having fun on your holiday!
Five more days in this beach with clear water!
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If I see well 28-30mVp-p, many thanks for the captures :-+
I do not care, but I don't need discuss about what I know.
Besides I already imagine he'll say.
But you notes much difference with the previous result? NO.
Why do you think that not?
If you don't believe me, I don't mind.
Cheers
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Carrington because I am not native english speaker, I don't understand your answer.
This is to me? Because my reference for ground noise of 28-30mV was for the BBAAHHOO results!
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Five more days in this beach with clear water!
Looks like paradise! I love the beach too, that's why I live in Florida near this Gulf beach.
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Please for comparison reasons, repeat the test of noise ground as decribed at post #1330, page 89 and give us the Vp-p value and the capture.
More about:
The "Mainboard" also have a DC/DC connected to ~5.54V it generate noise that goes to the analog power of the input stage. This DC/DC supply power to the entire DAC. :palm:
Below the shielding metal sheets of the input stage there is a 5V LDO, connected to ~5.54V (i.e Vdo <0.54). And if Owon did not put any filters (F.Bead) in the input of the analog power for the DAC, less to the input of the analog power for the input stage. This LDO is able to reject only some frequencies <1MHz. Similar for the 7905.
Yes, please for comparison reasons, repeat the test of noise ground as decribed at post #1330, page 89 and give us the Vp-p value and the capture.
More:
- To correct variations between channel 1 and 2 in some oscilloscopes Owon add extra resistors there where Owon think. :palm:
- The 5V regulator thermally affects more the channel 1, since it is closer, this explains its greater DC drift. :palm:
Now I do not think Owon would like to save money, rather it seems that, did not even know how to make the oscilloscope.
Well done Owon... This is not an oscilloscope, is shit. :--
Carrington, I agree that the SDS7102 is not a perfect oscilloscope, that's probably the reason this thread is quickly approaching page 100. In regard to your comment about the low drop linear regulator (LDO), I'm glad that Owon at least had the good sense to use linear rather than pollute the input stage with another PWM converter. Owon is fairly new in the Test Instruments arena, so I'm sure that there are quite a few tricks they haven't learned yet. However, many of us can't afford a scope from the high end manufacturers, and Owon's SDS7102 features/price ratio is very attractive. I, for one, don't regret buying the SDS7102, it doesn't fulfill all my wishes, but it reasonably fulfills my expectations for the price I paid. We all wish we could get better performance, so we continue to tinker with new ideas on how to improve the SDS7102 ourselves. This doesn't mean that we totally dislike our scopes, and most of the negative comments you may occasionally see are just venting. :-BROKE
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Carrington, I agree that the SDS7102 is not a perfect oscilloscope, that's probably the reason this thread is quickly approaching page 100. In regard to your comment about the low drop linear regulator (LDO), I'm glad that Owon at least had the good sense to use linear rather than pollute the input stage with another PWM converter. Owon is fairly new in the Test Instruments arena, so I'm sure that there are quite a few tricks they haven't learned yet. However, many of us can't afford a scope from the high end manufacturers, and Owon's SDS7102 features/price ratio is very attractive. I, for one, don't regret buying the SDS7102, it doesn't fulfill all my wishes, but it reasonably fulfills my expectations for the price I paid. We all wish we could get better performance, so we continue to tinker with new ideas on how to improve the SDS7102 ourselves. This doesn't mean that we totally dislike our scopes, and most of the negative comments you may occasionally see are just venting. :-BROKE
"However, many of us can't afford a scope from the high end manufacturers."
Yes, I agree, I buy one for the price. The problem is that in the end is expensive, think:
-All the lost time, looking for a solution, on how to improve the SDS7102 ourselves.
-Money spent in parts, etc.
And after check how OWONs customer service work, do you think that they will apply the warranty?
I doubt.
OWON could done it much better, and maybe with the same costs.
Anyway if you're happy with it, then perfect, this is an imperfect world.
But please OWON at least tries to attends decently to the customer.
"Owon is fairly new in the Test Instruments arena."
That's not our problem, OWON should know what he does. Don't you think?
I can assure you that after this experience I will never buy any product from OWON. No matter how cheap.
I'm tired, I don't want talk more about SDS7102's issues.
Cheers.
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Carrington, I agree that the SDS7102 is not a perfect oscilloscope, that's probably the reason this thread is quickly approaching page 100. In regard to your comment about the low drop linear regulator (LDO), I'm glad that Owon at least had the good sense to use linear rather than pollute the input stage with another PWM converter. Owon is fairly new in the Test Instruments arena, so I'm sure that there are quite a few tricks they haven't learned yet. However, many of us can't afford a scope from the high end manufacturers, and Owon's SDS7102 features/price ratio is very attractive. I, for one, don't regret buying the SDS7102, it doesn't fulfill all my wishes, but it reasonably fulfills my expectations for the price I paid. We all wish we could get better performance, so we continue to tinker with new ideas on how to improve the SDS7102 ourselves. This doesn't mean that we totally dislike our scopes, and most of the negative comments you may occasionally see are just venting. :-BROKE
C'mon though - I made the review and started this thread almost precisely two years ago - and Owon hasn't bothered to upgrade the firmware with even the simplest of features which I (and many others) felt were missing - and some of them would have been quite easy to add - so it doesn't seem to me as if Owon has learned anything in the last two years (at least in terms of supporting and satisfying their user base).
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I think that we judge the Owon with wrong parameteres.
Before two years when Owon presents this model the competition was Rigol and some Atten in low range of oscilloscopes.
The SDS Series has some plus vs others like large and better screen, deeper memory and some others. Before two years I think that them was enough, but not today.
They aren't going to presentation a new marvelous fw, for them it is adequate this basic fw.
Probably, they have different philosophy or their target group is difference from that of an experience user.
Today the things are different, more competitors and the new Rigol 2XXX Series one level upper with double price of course!
For me the time was expending for improvement the noise ground level is like school and I haven't problem with this. I am sure for others owners like Carrington this is a lost time and the nervous system is going to break!
Different people with different needs!
@ TomC = marvelous place and I think that your choice is right. The place that presents before is held to South Peloponissos (Laconia, Marathias beach). The water is deep clearly, if you dive with apnoia you can see over 20 metres.
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C'mon though - I made the review and started this thread almost precisely two years ago - and Owon hasn't bothered to upgrade the firmware with even the simplest of features which I (and many others) felt were missing - and some of them would have been quite easy to add - so it doesn't seem to me as if Owon has learned anything in the last two years (at least in terms of supporting and satisfying their user base).
Wow marmad, the thread that you started hit a new milestone! 100 pages, Congratulations! :-+
I'm also disappointed with the progress in the firmware side, more so with unresolved bugs than the lack of new features. Owon's behavior in my opinion is counterproductive, but is their choice to decide where they want to go in the future. The main point I've attempted to make, is that in spite of the shortcomings, we don't all consider our Owon scopes to be totally manure. I'm still enthusiastic about the many things that I can do with my Owon DSO that were simply not possible with my old Tek CROs. I know that you now own a 70MHz Rigol DSO with very nice features. In my case, I already owned two 60MHz Tek CROs, so I wanted to get at least 100-200MHz for a new DSO. The SDS7102 offered 100MHz and was usable to 200MHz for a price I could afford. So I still think I did fine for my needs. But I do agree that Owon could do better, at least in popularity, if they would cater to user base needs and desires. There is nothing like word of mouth, in my opinion!
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Wow marmad, the thread that you started hit a new milestone! 100 pages, Congratulations! :-+
Well, congratulations go to all the members who've contributed here. And the length of the thread is a testament to the fact that Owon IS providing a product at a certain price point - and with particular features - that people still find desirable.
I'm also disappointed with the progress in the firmware side, more so with unresolved bugs than the lack of new features. Owon's behavior in my opinion is counterproductive, but is their choice to decide where they want to go in the future. The main point I've attempted to make, is that in spite of the shortcomings, we don't all consider our Owon scopes to be totally manure. I'm still enthusiastic about the many things that I can do with my Owon DSO that were simply not possible with my old Tek CROs. I know that you now own a 70MHz Rigol DSO with very nice features. In my case, I already owned two 60MHz Tek CROs, so I wanted to get at least 100-200MHz for a new DSO. The SDS7102 offered 100MHz and was usable to 200MHz for a price I could afford. So I still think I did fine for my needs. But I do agree that Owon could do better, at least in popularity, if they would cater to user base needs and desires. There is nothing like word of mouth, in my opinion!
Sure, I agree. I'm all for Owon quashing bugs and improving hardware as their primary goal - just wish they would have thrown a slightly larger percentage of their efforts into adding a few new features (e.g. fine scale control).
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And after check how OWONs customer service work, do you think that they will apply the warranty?
I doubt.
Well I have no doubts. My scope's first fan became noisy after few months of use and was very quickly replaced.
Another problem was with recent firmwares, my scope would freeze from time to time when booting. Owon and my distributor couldn't figure out what was wrong and replaced the main board. It's been working fine since then.
Also it's strange that you, who doesn't care about Owon at all, is spending so much energy hating Owon and spreading the hate. Can't you just forget about us and move on to threads about good scopes?
Also in some cases, Owon, with all of its problems, is the only option. For example in my country cheapest Tektronix or LeCroy scopes cost couple of thousands of Euros. CROs start at around 700€ (and that's for 70 Mhz ones). "Local" Rigol distributor is in Italy, which makes them uncompetitive. This environment combined with salaries makes it worthwhile to take time to work out Owon's quirks.
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Well I have no doubts. My scope's first fan became noisy after few months of use and was very quickly replaced.
Another problem was with recent firmwares, my scope would freeze from time to time when booting. Owon and my distributor couldn't figure out what was wrong and replaced the main board. It's been working fine since then.
Congratulations, All the best!
Also it's strange that you, who doesn't care about Owon at all, is spending so much energy hating Owon and spreading the hate. Can't you just forget about us and move on to threads about good scopes?
Hate? You are mistaken. :o
I think a lack of respect, you're telling me I have to do! Really? I say: FREEDOM
Also in some cases, Owon, with all of its problems, is the only option. For example in my country cheapest Tektronix or LeCroy scopes cost couple of thousands of Euros. CROs start at around 700€ (and that's for 70 Mhz ones). "Local" Rigol distributor is in Italy, which makes them uncompetitive. This environment combined with salaries makes it worthwhile to take time to work out Owon's quirks.
I think there are more fish in the sea. :)
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Here is the latest revision of the schematic for my old PSU. Learning in detail how each component works is proving to be more challenging than I foresaw. So I'm still working on the theory of operation paper. So far I've found a few apparent blunders that may be helpful in quashing the GND noise issue. Specially in the snubber circuits. So I'll be posting my views and opinions on this soon.
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Great work TomC, keep going in the same way! :-+
Can you give me the Version of the newer psu board? I am looking at your photos that you had upload but there isn't seem nothing!
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Here is some last mods to my adapter Version 3.0
I have upload a video to see how is the real pattern of ground noise and how this changed at the time (it is taken from my mobile with 640X480 resolution).
The refresh rate of capture of samsung mobile is lower than real refresh rate of Owon. For this reason sometimes there is forward-reward movement of peaks at the left-right side of noise pattern.
The range of noise is 38-60mV peak to peak (Acquires Mode to Peak), with the most values btw 44-50mV.
This is not bad, if we think the marvelous 28-30mV of BBAAHHOO member with a dozen of heavy modifications.
I have attached the mods that I have done to the adapter board (attention this is Ver. 3.0). I haven't attached the mods on psu board, this followes the signs that has been marked at the post #1383 (a lot of smd decoupling capacitors).
Owon SDS7102V Ground Noise after some mods (https://www.youtube.com/watch?v=qq17cSDflyE#)
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Great work TomC, keep going in the same way! :-+
Can you give me the Version of the newer psu board? I am looking at your photos that you had upload but there isn't seem nothing!
There is no version number. I was wondering the same thing when I first got the board. Maybe the board is a prototype, I don't know! Very strange!
Good work on the mods, I watched the video and the noise seems pretty low. :-+
I haven't done any changes on the old PSU yet. Still working purely on theory, maybe I'll be surprised at what I see when I power it up and look at some waveforms. But I don't want to get ahead of myself for now, I'm getting a little impatient though!
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Very strange, really! A thumb down :-- for this to Owon.
(this adding latter) = TomC if you see the post of dgmoore78@yahoo.com (post 1331) measures 34mV peak to peak (serial =SN#SDS71021319xxx). This is stranger vs yours result. Probably the Owon has done some other changes (to adapter board of course) but there are no available until now...
You have a lot of time to investigate more the psu circuit. Who knows, maybe you find a smart solution for low emi radiation.
I am very curious about BBAAHHOO works. He took individual voltages from the psu board without needs the dc-dc adapter convertors that produce a lot of noise.
Maybe the more sophisticated solution is the redesign of psu board with independed voltages.
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Here is a partial draft of the Theory of Operation paper I've been preparing for my old PSU.
Keep in mind that I'm not an expert on SMPS, so although at this point I believe things work the way I explain them in this paper, I'm just learning myself. At this point, everything in this paper is theoretical, I haven't experimentally verified any of it. :scared: I plan to do that once I finish the theoretical research and complete the paper.
As always, any comments, disagreements, suggestions, etc. are welcome! I can use all the help I can get.
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TomC you have done marvelous analysis of operational theory of circuit.
I haven't the appropriate knowledge to help you about this but for a quick reading that I done note your proposal to faster diodes and check of values to snubber circuit.
Really I'll waiting you to finished this great work!
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This is a better quality photo of my old PSU board printed circuit side that can be used together with the previously posted schematic to explore the circuit topology. On the original you could clearly see all the component values, but I had to compress a little to post it here. So you may have to guess a little in some cases.
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This is the matching component side photo for the previous post. I removed all the gook that the factory uses to prevent audible buzzing from the high frequency switching. I couldn't read some of the component labels because of it.
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I am very curious about BBAAHHOO works. He took individual voltages from the psu board without needs the dc-dc adapter convertors that produce a lot of noise.
Lemon, I've been reviewing BBAAHHOO posts, and I can't find where he derived other voltage sources from the PSU board. From what I see, it seems that all he did is add filtering to the existing voltage sources. Is there something that you see that I'm missing?
BBAAHHOO, can you clarify this? If you are using voltage sources other than the original, can you give us more details on how you did this?
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For example look at the attachment photo of post 1465.
What is that he is doing here?
He removed all the dc-dc convertors U2, U13, U21 from adaptor board and drives the appropriate voltages from heavily modificate psu board. For this reason look at the schematics of post 1462. He draws the circuit that he uses for independent outputs of 3.3/5.5/6.8/-7.4 Volts
The result are very fine but the same result had the rf-loop with other way of modification and as said to my previous post, seems the same result have and Owon to the newer ocilloscopes.
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Hi to everyone. My new results. - From the network 18-22 Vpp, battery 12-18 Vpp. Reduced noise from the screen. Added capacitors on the conclusions of the LCD screen ( 0.08 nF which are used in many LCD screens). After this enhancement, there are some distortions on the monitor output.
All power DC-DC original. Added filter and transfer to another place.
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I've been trying to download BBAAHHOO's zip file from two different computers but all I get is html review of Owon sds... The log next two it says downloaded 2 times, so I don't know if there is a problem on my end or with the blog's download mechanism. Is any one else having this problem?
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Author of the article.
https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/?action=dlattach;attach=56620 (https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/?action=dlattach;attach=56620)
Snubbers Using Standard Recovery Diodes.
Cheap and slow is not bad. ???
Designing R2CD Snubbers Using Standard Recovery Diodes
http://www.intusoft.com/lit/Designing%20R2CD%20Snubbers%20Using%20Standard%20Recovery%20Diodes.pdf (http://www.intusoft.com/lit/Designing%20R2CD%20Snubbers%20Using%20Standard%20Recovery%20Diodes.pdf)
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I've been trying to download BBAAHHOO's zip file from two different computers but all I get is html review of Owon sds... The log next two it says downloaded 2 times, so I don't know if there is a problem on my end or with the blog's download mechanism. Is any one else having this problem?
TomC, just I downloaded without problem, the files must had Russian characters because they translated automatically to Greek letters with numbers. He tells us that removed all the dc-dc convertors and put all of them in a new board with appropriate filtering... Am I right BBAAHHOO?
At your zip file you have enclosed a new photo with some mod to mainboard. Are these the capacitors that you said for lcd display? I can't understand what you have done, maybe it needs the original photo vs the mod photo.
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BBAAHHOO looks the comparison of the attachment photo, the left is yours the right is factory original. What kind capacitors are they because you have bridged all of them with the first two parallel pins.
This is your mod for the lcd.
Your results are great!
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Author of the article.
https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/?action=dlattach;attach=56620 (https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/?action=dlattach;attach=56620)
Snubbers Using Standard Recovery Diodes.
Cheap and slow is not bad. ???
Designing R2CD Snubbers Using Standard Recovery Diodes
http://www.intusoft.com/lit/Designing%20R2CD%20Snubbers%20Using%20Standard%20Recovery%20Diodes.pdf (http://www.intusoft.com/lit/Designing%20R2CD%20Snubbers%20Using%20Standard%20Recovery%20Diodes.pdf)
Flash2light thanks for the link. The R2CD is very interesting applying theory and must we give the appropriate attention!
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Just TomC has concentrated to psu board, I am thinking to focus to the adapter board.
I don't have the time to make a schematic for all this board but I'll search some dc-dc convertors, difference btw Ver 3.0 and 3.2 and so on.
At the first I am looking the AOZ1094AI dc-dc convertor that produce the 5.5V.
What Owon makes at the the two versions? Look at the attachment photo (left is 3.2, right is 3.0 version).
At the version 3.2 corrects the badly cutting of gnd that previous was made (point 1). Removed the smd capacitor C36 (point 2), adding a second inductor 5.6uH with some smd decoupling capacitors (point 3). The changes was few and very easy to make but is that according to AOZ1094 datasheet?
The next schematic is from datasheet of convertor, a general proposal for 3.3V output. For 5V output the factory suggests L1=5.6uH, Rc=31.6KOhms, Cc=1nF.
For what reason the Owon uses two 5.6uH inductors? For what reason has made mods by hand on version 3.0 with adding a 10uH inductor? Of course was the eliminate the noise but what are they compute.... ?
If you looking more carefully at the schematics, missing some components!
Where the C5=1000pF capacitor that joined the AGND and Enable?
Where is the parallel to diode Rs and Cs components?
At the output the factory suggest two 22uF electrolytic capacitor or some combination : "For lower output ripple voltage across the entire operating temperature range, X5R or X7R dielectric type of ceramic, or other low ESR tantalum or aluminum electrolytic capacitors are recommended to be used as output capacitors."
Have all these in my mind I'll make a check again and I am going to follow the datasheet...
Please, if someone looks the values of smd resistor R18, R19, R20 and R21 on Version 3.2
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Author of the article.
https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/?action=dlattach;attach=56620 (https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/?action=dlattach;attach=56620)
Snubbers Using Standard Recovery Diodes.
Cheap and slow is not bad. ???
Designing R2CD Snubbers Using Standard Recovery Diodes
http://www.intusoft.com/lit/Designing%20R2CD%20Snubbers%20Using%20Standard%20Recovery%20Diodes.pdf (http://www.intusoft.com/lit/Designing%20R2CD%20Snubbers%20Using%20Standard%20Recovery%20Diodes.pdf)
Flash2light, thanks a lot for the link. :-+
When I was researching the snubber circuits I looked at many articles, but didn't run into anything that mentioned the R2CD developed by the Chinese. I was just guessing at the intent of the designer when I said that the extra resistor "may be an attempt to dampen the ringing frequency with a resistor value that matches the resonant's circuit impedance", luckily, as it turns out, I wasn't too far from the truth.
The R2CD concept is interesting, and certainly reduces component cost while providing a solution that has better performance than an RCD snubber. The article doesn't compare the R2CD EMI performance to a combination of traditional RCD and RC snubbers, so I'm still planning to try that approach during the experimental phase of the project.
Again, thanks a lot for taking the time to share this information with me. It clears up several questions that I had in my mind while trying to understand the PSU circuit. :-+
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Just TomC has concentrated to psu board, I am thinking to focus to the adapter board.
I don't have the time to make a schematic for all this board but I'll search some dc-dc convertors, difference btw Ver 3.0 and 3.2 and so on.
At the first I am looking the AOZ1094AI dc-dc convertor that produce the 5.5V.
What Owon makes at the the two versions? Look at the attachment photo (left is 3.2, right is 3.0 version).
At the version 3.2 corrects the badly cutting of gnd that previous was made (point 1). Removed the smd capacitor C36 (point 2), adding a second inductor 5.6uH with some smd decoupling capacitors (point 3). The changes was few and very easy to make but is that according to AOZ1094 datasheet?
The next schematic is from datasheet of convertor, a general proposal for 3.3V output. For 5V output the factory suggests L1=5.6uH, Rc=31.6KOhms, Cc=1nF.
For what reason the Owon uses two 5.6uH inductors? For what reason has made mods by hand on version 3.0 with adding a 10uH inductor? Of course was the eliminate the noise but what are they compute.... ?
If you looking more carefully at the schematics, missing some components!
Where the C5=1000pF capacitor that joined the AGND and Enable?
Where is the parallel to diode Rs and Cs components?
At the output the factory suggest two 22uF electrolytic capacitor or some combination : "For lower output ripple voltage across the entire operating temperature range, X5R or X7R dielectric type of ceramic, or other low ESR tantalum or aluminum electrolytic capacitors are recommended to be used as output capacitors."
Have all these in my mind I'll make a check again and I am going to follow the datasheet...
Please, if someone looks the values of smd resistor R18, R19, R20 and R21 on Version 3.2
That's great Lemon, :-+
Just like you I'd like to see solutions to the GND noise issue that can be easily and effectively implemented. I suspect that there are quite a few things that can be improved on the Owon design with simple changes to the existing board configuration. This is what I plan to aim for during the experimental phase of my PSU analysis. To discover these possibilities is probably going to take a lot of careful analysis before implementing any changes.
Since you don't have a version 3.2 board and I do, I'm going to try to get the best possible pictures I can get from my board and post them. I'll try to make sure that the component values are readable. Good luck with this project!
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Thanks TomC for help, I'll wait for the adaptor board photo of version 3.2.
I'll upload the photo of versions 3.0 too.
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Here are some photos of the version 3.2 adapter board and the new PSU board.
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What kind capacitors are they because you have bridged all of them with the first two parallel pins.
http://www.digikey.es/product-search/en/capacitors/capacitor-arrays/131080?k=capacitor (http://www.digikey.com/product-search/en/capacitors/capacitor-arrays/131080?k=capacitor)
BBAAHHOO very good idea, also add resistors in series would be nice -> rise time, do not run much, that's the idea.
I'm not going to do, because I destroy the board. LOL...
Cheers.
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Here is a link to the uncompressed version of the Version 3.2 Adapter and New PSU photos. This link has an expiration date of November 2013. Until then the photos will be available for viewing or download.
http://sdrv.ms/15hxusH (http://sdrv.ms/15hxusH)
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Hi to everyone. My new results. - From the network 18-22 Vpp, battery 12-18 Vpp. Reduced noise from the screen. Added capacitors on the conclusions of the LCD screen ( 0.08 nF which are used in many LCD screens). After this enhancement, there are some distortions on the monitor output.
All power DC-DC original. Added filter and transfer to another place.
BBAAHHOO,
I finally was able to download your file. The noise levels I saw on your photos are very low, better than anything I've seen before. Congratulations! :-+
When you say that there are some distortions with the monitor output, I take it that you mean on something like a TV or computer monitor connected to the VGA output. Not the scope's TFT screen. Let me know if that's not correct.
--To other members that may have had trouble downloading the ZIP file --
I tried to download this file from all 3 computers in our home, none of them was successful. All 3 computers run Windows 7 64bits and the browser is Internet Explorer. I suspect something is incompatible with this browser and the EEVblog website. I finally was able to download the file after installing a Download Manager on one of the computers. The other 2 computers are still unable to download this file.
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This is ver 3.3
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This is ver 3.3
Flash2light,
The component side looks identical to version 3.2. Is there an SMD capacitor underneath C34? That's the only thing Owon had me add to my 3.2 adapter board when I purchased a new PSU board.
I'm also curios about the GND noise level on your scope, on page 92 post 1373 you can see the GND noise level on my scope after I replaced the PSU board and modified the adapter board with an SMD capacitor under C34. It would be very nice if you posted some captures of the GND noise level on your scope for comparison.
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This shows the noise.
original condition. Not modified.
Ver. sds7102 1319 331
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without the probe.
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Here is a link to the uncompressed version of the Version 3.2 Adapter and New PSU photos. This link has an expiration date of November 2013. Until then the photos will be available for viewing or download.
http://sdrv.ms/1cOVr1M (http://sdrv.ms/1cOVr1M)
Please have in mind that it demands account to login.
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This is ver 3.3
Flash2light,
The component side looks identical to version 3.2. Is there an SMD capacitor underneath C34? That's the only thing Owon had me add to my 3.2 adapter board when I purchased a new PSU board.
I'm also curios about the GND noise level on your scope, on page 92 post 1373 you can see the GND noise level on my scope after I replaced the PSU board and modified the adapter board with an SMD capacitor under C34. It would be very nice if you posted some captures of the GND noise level on your scope for comparison.
It is really the upper part is identical with paths reference and IC.
It is very strange what this happens to you.
If you remember the member dgmoore78@yahoo.com (post 1331) measures 34mV peak to peak (serial =SN#SDS71021319xxx) also.
The 28mVp of Flash2light or 34mV of dgmoore78@yahoo.com are very well in comparison to yours 70mV.
And something for our knowledge, the version 3.3 was made of 5th November of 2012!
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This shows the noise.
original condition. Not modified.
Ver. sds7102 1319 331
This result is acceptable. I am waiting for both board PSU and DC/DC, last version. Finally, it seems that this is solved, after many months ...
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Carrington, thanks for the link with information about capacitor type.
Can you tell us how much was the cost of the two boards and how you paid them?
Of course we'll waiting what versions you'll get up and some photos of course.
For our file upload some photos from adapter version 3.0 (not modification).
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...
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where is the ferrite? I have a ferrite flat cable.
I have not tried its effect.
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Some kind of observations with a quick see of adapter version 3.2 vs 3.0
From what I have seen to the adapter version 3.2 it is almost identical the 5.5 and 3.3 dc-dc circuits.
The 3.3 is quite identical, the 5.5 differs only at output that cuts the gnd (version 3.0), also they used at output after the electrolytic capacitor an inductor (version 3.2) with some smd decoupling capacitors (better filtering).
Also the path for -7.6V is the same and has the same decoupling capacitors. Generally the topology and routing of schematics at the two dc-dc converters are 95% same.
The big difference is at TFT Backlight LED power supply. There is an other IC (really can someone find what is S126k) probably a TPS61161A (I don't see clearly) with different power supply. At version 3.0 the output of 5.5 V divides at two with the left one to drive the TFT Backlight Led PS, that isn't happening to version 3.2 that the power supply of TFT BLPS held from 8.4V of PSU board direct.
I am very curious, what adapter version will get up the Carrington...
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where is the ferrite? I have a ferrite flat cable.
I have not tried its effect.
I don't know if the Adapter Ver 3.2 had a flat ferrite but mine Ver. 3.0 hadn't.
Please look if there are and others ferrites inside.
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Carrington, thanks for the link with information about capacitor type.
You are wlecome!
Can you tell us how much was the cost of the two boards and how you paid them?
OWON offered me only the PSU and the capacitor ($ 50). I need too the adapter board, since my adapter board is the 3.0.
OWON told me that with the capacitor is sufficient for the version 3.0. :wtf: We know that is not true, I tried to explain to them that this is not enough, but no way...
At the end I could get the boards through Aidetek US, this has made all management for me.
And here comes the best: I could pay through PAYPAL, and all cost me only USD45 (postage included). Since the new PSU has been a gift because I buy the oscilloscope to it. I think that after telling the whole "battle" with Owon, it had compassion on me.
Of course we'll waiting what versions you'll get up and some photos of course.
You can count on it. I can not wait, I want to get off this problem. :phew:
I really do not want to know anything more about OWON.
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What are you said my friend? 45$ only? :-+
I have bought the Owon for the Aidetek USA (but is was coming directly from China to my country). I think must to be a contact with them about this. Many many thanks for this information.
Have you tracking information for the arrived day?
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What are you said my friend? 45$ only? :-+
I have bought the Owon for the Aidetek USA (but is was coming directly from China to my country). I think must to be a contact with them about this. Many many thanks for this information.
What are you waiting?
Mine also came directly from China.
Have you tracking information for the arrived day?
I have no tracking number, because Aidetek has not sent anything yet. He had problems with the manufacturer to get the adapter board. And probably Aidetek not receive it until the next week.
Cheers.
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The big difference is at TFT Backlight LED power supply. There is an other IC (really can someone find what is S126k) probably a TPS61161A (I don't see clearly) with different power supply.
"This is good candidate for this......but it depends... manufacturing lot... "
http://www.gmt.com.tw/product/datasheet/EDS-5126.pdf (http://www.gmt.com.tw/product/datasheet/EDS-5126.pdf)
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rf-loop this is it.
Many thanks for the link :-+
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Here is a link to the uncompressed version of the Version 3.2 Adapter and New PSU photos. This link has an expiration date of November 2013. Until then the photos will be available for viewing or download.
http://sdrv.ms/1cOVr1M (http://sdrv.ms/1cOVr1M)
Please have in mind that it demands account to login.
Sorry for the bad link, I revised it on the original post and here is the correct link also.
http://sdrv.ms/15hxusH (http://sdrv.ms/15hxusH)
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where is the ferrite? I have a ferrite flat cable.
I have not tried its effect.
I don't know if the Adapter Ver 3.2 had a flat ferrite but mine Ver. 3.0 hadn't.
Please look if there are and others ferrites inside.
My scope, with adapter version 3.2, also has a large flat ferrite on the TFT screen cable.
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Now it is not strange, is a thriller!
Can someone to give us a photo of adapter 3.3 from under side?
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This is ver 3.3 dc-dc board under side.
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This is ver 3.3 dc-dc board under side.
That's identical to mine (3.2), but yours had the smd capacitor under C34 installed at the factory.
Flash2light, can you read the markings on U2 on your board, on mine I see OBT 2?K CX10. The question mark is a character that I can't make out.
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This is ver 3.3 dc-dc board under side.
That's identical to mine (3.2), but yours had the smd capacitor under C34 installed at the factory.
Flash2light, can you read the markings on U2 on your board, on mine I see OBT 2?K CX10. The question mark is a character that I can't make out.
I think I answered my own question about U2, I just found this on the internet.
http://www.s-manuals.com/smd/ob (http://www.s-manuals.com/smd/ob)
You can download the datasheet for OBT marking from this link.
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Modified AC-DC power supply.
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This is ver 3.3 dc-dc board under side.
That's identical to mine (3.2), but yours had the smd capacitor under C34 installed at the factory.
Flash2light, can you read the markings on U2 on your board, on mine I see OBT 2?K CX10. The question mark is a character that I can't make out.
I think I answered my own question about U2, I just found this on the internet.
http://www.s-manuals.com/smd/ob (http://www.s-manuals.com/smd/ob)
You can download the datasheet for OBT marking from this link.
Nice TomC.
Now it is clearly, an other big difference btw ver. 3.0 and 3.2 is the IC for backlight led. It is completely differente circuits.
Your mystery is like "Mitos of Ariadnes" (from Greek Mythology) same psu, identical adapter but the noise is differente, but remaining the answer of Flash2light what is marking of U2 in ver. 3.3. Probably, there is a difference there...
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Modified AC-DC power supply.
????????, in your photos there is a difficulty to see someone clearly, because the pcb had a lot of residual of soldering.
You can removed them with a lot of isopropyl alchool.
I don't know if the flux that containing in core of your solder is water soluble (that means that is removed easy with water) or you used a lot of extra paste of flux, but usually fluxes are RA (rosin acid) and their residuals makes a corrosion in time.
It is better to removed with an appropriate solution.
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The design of version 3.0 is crap, continuous gnd plane cuts, parallel capacitors that resonate at frequencies where noise is generated, DC/DC Boost with input connected to critical places (everyone should know that at the input is where more noise is generating by a boost), etc.
I tried to explain to OWON that for those who have the 3.0 version a 1n capacitor is not enough, but there is no way. :palm:
Now it is clearly, an other big difference btw ver. 3.0 and 3.2 is the IC for backlight led. It is completely differente circuits.
... remaining the answer of Flash2light what is marking of U2 in ver. 3.3. Probably, there is a difference there...
For this reason they changed the G5126 by a TPS61161A. The G5126 don't support more than 5.5V at the input.
And if I'm not mistaken lack a capacitor that in combination produces resonancere. True? Look near C45 in the 3.2 and 3.3 version.
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I can get better pictures until Monday.
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Flash2light, we'll waiting for that because it is not clearly the photo at U2.
From what I can see it marks like:
OBT
24J
PDW?
The TomC reference was:
OBT
2?K
CX10.
But if you search to internet for TI TPS61160A (Led Driver) the icon of IC is differente to these.
(http://www.ti.com/graphics/folders/partimages/xTPS61161A.jpg.pagespeed.ic.qsTy2s7VBI.jpg)
It is meaning that they are compatible to TI IC made to china of course.
I don't have in front of me an adapter Ver. 3.2 or 3.3 but you can check the following diagram from Texas Instrument. It is typical diagram for TPS61160A with fixed and dimming network.
I don't see at the pcb routing how they done the dimming network of leds.
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The design of version 3.0 is crap, continuous gnd plane cuts, parallel capacitors that resonate at frequencies where noise is generated, DC/DC Boost with input connected to critical places (everyone should know that at the input is where more noise is generating by a boost), etc.
I tried to explain to OWON that for those who have the 3.0 version a 1n capacitor is not enough, but there is no way. :palm:
Now it is clearly, an other big difference btw ver. 3.0 and 3.2 is the IC for backlight led. It is completely differente circuits.
... remaining the answer of Flash2light what is marking of U2 in ver. 3.3. Probably, there is a difference there...
For this reason they changed the G5126 by a TPS61161A. The G5126 don't support more than 5.5V at the input.
And if I'm not mistaken lack a capacitor that in combination produces resonancere. True? Look near C45 in the 3.2 and 3.3 version.
Exactly and this is the answer why they used the output of AOZ1094 for input voltage to G5126 and not the 8.4V direct from PSU like Ver. 3.2/3.3.
But at the second paragraph I am loosing you. The C45 is a capacitor to AOZ1094 circuits (+5.5V). What is relation with the Backlight Led Circuit of Ver. 3.2/3.3?
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https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/msg264016/#msg264016 (https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/msg264016/#msg264016)
But at the second paragraph I am loosing you. The C45 is a capacitor to AOZ1094 circuits (+5.5V). What is relation with the Backlight Led Circuit of Ver. 3.2/3.3?
Ok, it's just that in 3.0 version there is a small SMD capacitor in parallel with C45, these resonate at frequencies where noise is generated by the DC/DC. In the new version it (if I'm not mistaken) is not populated.
To design is better to have a minimum of experience, if not, then these things happen. I keep wondering how many "slip" more ...
The simplest thing that I can think to see how much noise is generated on the main board is power it by a set of batteries (5.5, 3.3, 8.4, -7), except the power of the screen, where we must use the appropriate driver (but is easy also isolate it with a battery).
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Flash2light, we'll waiting for that because it is not clearly the photo at U2.
From what I can see it marks like:
OBT
24J
PDW?
The TomC reference was:
OBT
2?K
CX10.
But if you search to internet for TI TPS61160A (Led Driver) the icon of IC is differente to these.
(http://www.ti.com/graphics/folders/partimages/xTPS61161A.jpg.pagespeed.ic.qsTy2s7VBI.jpg)
It is meaning that they are compatible to TI IC made to china of course.
I don't have in front of me an adapter Ver. 3.2 or 3.3 but you can check the following diagram from Texas Instrument. It is typical diagram for TPS61160A with fixed and dimming network.
I don't see at the pcb routing how they done the dimming network of leds.
The lines under OBT are not indented, probably batch number but not related to device type. The attachment is from TI website. There is no room on IC for markings in the pictured icon, probably just a picture for show, but not the way actual IC looks like.
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Try here: http://www.ecadata.de/searchnew/index2.html (http://www.ecadata.de/searchnew/index2.html)
Bad luck does not give a result, but it is clear, SMD Marking:
OBV = TPS61160A
OBT = TPS61161A
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https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/msg264016/#msg264016 (https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/msg264016/#msg264016)
But at the second paragraph I am loosing you. The C45 is a capacitor to AOZ1094 circuits (+5.5V). What is relation with the Backlight Led Circuit of Ver. 3.2/3.3?
Ok, it's just that in 3.0 version there is a small SMD capacitor in parallel with C45, these resonate at frequencies where noise is generated by the DC/DC. In the new version it (if I'm not mistaken) is not populated.
To design is better to have a minimum of experience, if not, then these things happen. I keep wondering how many "slip" more ...
The simplest thing that I can think to see how much noise is generated on the main board is power it by a set of batteries (5.5, 3.3, 8.4, -7), except the power of the screen, where we must use the appropriate driver (but is easy also isolate it with a battery).
Yeap, if I remember well this capacitor that missing now on the Ver. 3.2/3.3 was C36 a small one.
From the works of Russian member BBAAHHO seems that the mainboard has a very little noise. With his modifications achieves noise about 30mV that is perfect.
Seems that this oscilloscope has designed from different groups. The works for the mainboard is quite good. There is no noise at the front end and the bandwidth is better than the specifications. The badly was at the psu and adapter board, here the Owon designs a crap and after one year and a half seems to resolve the badly design of the two boards.
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Flash2light, we'll waiting for that because it is not clearly the photo at U2.
From what I can see it marks like:
OBT
24J
PDW?
The TomC reference was:
OBT
2?K
CX10.
But if you search to internet for TI TPS61160A (Led Driver) the icon of IC is differente to these.
(http://www.ti.com/graphics/folders/partimages/xTPS61161A.jpg.pagespeed.ic.qsTy2s7VBI.jpg)
It is meaning that they are compatible to TI IC made to china of course.
I don't have in front of me an adapter Ver. 3.2 or 3.3 but you can check the following diagram from Texas Instrument. It is typical diagram for TPS61160A with fixed and dimming network.
I don't see at the pcb routing how they done the dimming network of leds.
The lines under OBT are not indented, probably batch number but not related to device type. The attachment is from TI website. There is no room on IC for markings in the pictured icon, probably just a picture for show, but not the way actual IC looks like.
Unfortunately, it isn't TI IC, it is clearly a copy made in China with the same mark (OBT). If you look at the end of datasheet pages, the TI has drawn the schema of this chip. It is exactly the same like the photo that upload before.
But, for me it no matter about this, they have copy exactly the circuit of TI (perhaps the TI have better characteristics), the important is to check how the Owon makes the routing and what components choosed vs datasheet.
The rf-loop had made a lot of modification to this part of adapter and somebody had writes the phrase "which is design this board, he was drunk!"
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:wtf: I was, and the exact phrase was: "Who designed this? He was drunk?"
But who knows the reason... Maybe he did not know what he was doing or did not care...
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Seems that this oscilloscope has designed from different groups.
Wonder!
The works for the mainboard is quite good.
I want to believe! But I think not.
There is no noise at the front end and the bandwidth is better than the specifications.
Better BW, deliberate I think and, very easy to get.
There is no noise at the front end, wow if this is true then OWON you have been very lucky.
To get that Rigol has used lots of filters (ferrite bead / EMI Filter / LDO / shielding) and good design technique. But still have ~ 1mV of noise at full BW and in the worst case.
The badly was at the psu and adapter board, here the Owon designs a crap and after one year and a half seems to resolve the badly design of the two boards.
Okay, but not covered by the warranty.
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Better BW, deliberate I think and, very easy to get.
There is no noise at the front end, wow if this is true then OWON you have been very lucky.
To get that Rigol has used lots of filters (ferrite bead / EMI Filter / LDO / shielding) and good design technique. But still have ~ 1mV of noise at full BW and in the worst case.
Of course it have noise in front end.
Here you can find data. (http://owon.forumup.com/viewtopic.php?t=177&mforum=owon)
It do not loose with Rigol. (exept that Owon lowest full BW is 5mV/div.
Rigol have 0.5mV/div (with more than two div peak peak noise.).
But then, if reduce BW with filter or with averagind (capture averaging or high-res averaging) there can get slow and low signal very nice)
Also this noise level in front end (and BW) is proofed by many FFT tests what also are available.
(there can find test where full not clipped level is displayed and then signal dropped 60dB and signal can still rise very clearly over base noise. If this front end noise level is bad, it really can not do it.
Also we all know that Rigol front end is nearly like as copied from (older and littlebit noisier version) Owon.
Also it is good note that Owon real BW is over 170MHz typically (and over 200MHz typically in voltage band II) when look front end noise, BW need also note.
My strong suspect is also that maain board designer is different people than PSU and perhaps also adapter board. Specially PSU design "signature" is so different hat same people can not do this. Or he really have been drunk when he draw PSU.
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Carrington about BW, you know (I think) the works of rf-loop, he has show us that this oscilloscope has over 200MHz bandwidth.
If I remember well you have additional the Rigol 2000 Series, I think that is one category over than SDS7102 and it is not fair to compare the two of them. About Rigol DS1052 or DS1102 that is the competition.
But if I remember well, the noise of SDS at full BW (5mV) is under 1mV. At the beginning when the noise gnd is very high (160-200mV) I couldn't to examine a signal with a few mV, it was full with artifacts and not stable - only with my old analoge Hameg I could.
Today with my mods (I have a noise gnd 40-55mV peak to peak) there is no any difference between Hameg and Owon in signals with a few mV, very stable and clearly.
For the warranty about gnd noise as very right you said, all of them give them many :--
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Oops, me and rf-loop write at the same time...
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Your mystery is like "Mitos of Ariadnes" (from Greek Mythology) same psu, identical adapter but the noise is differente, but remaining the answer of Flash2light what is marking of U2 in ver. 3.3. Probably, there is a difference there...
Well that's not too bad, I'll be more scared to look around for the answer if it resembled the story of Medusa, it wouldn't be cool turning to stone.
There are a couple of things I've been thinking about. I took a real good look at my new PSU board and discovered that one of the new decoupling capacitors is probably missing. There is no capacitor where C23 is supposed to be. C23 is supposed to be at the end of the adapter board connector. I see glue residue, as if the component was there but fell off during the soldering process. However, I don't think this would cause such a big difference in noise by itself.
Flash2light, can you tell me if this capacitor is present on your PSU board?
The other thing I've been thinking about is that I don't have the battery option. With a battery installed you have additional filtering for the 8.4V supply. The battery itself can act as a super capacitor. I don't know for sure if the results from dgmoore78@yahoo.com and Flash2light were obtained with the optional battery installed.
dgmoore78@yahoo.com and Flash2light, can you clarify this, and if possible, if your test was done with the battery installed, can you do the test again without the battery?
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Your mystery is like "Mitos of Ariadnes" (from Greek Mythology) same psu, identical adapter but the noise is differente, but remaining the answer of Flash2light what is marking of U2 in ver. 3.3. Probably, there is a difference there...
Well that's not too bad, I'll be more scared to look around for the answer if it resembled the story of Medusa, it wouldn't be cool turning to stone.
...
Tomc: Is the difference between yours and these very marked?
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Carrington about BW, you know (I think) the works of rf-loop, he has show us that this oscilloscope has over 200MHz bandwidth.
Yes I've seen it. Just send the appropriate command to the LMH6518 is in the input stage and you will have much more BW.
If I remember well you have additional the Rigol 2000 Series, I think that is one category over than SDS7102 and it is not fair to compare the two of them. About Rigol DS1052 or DS1102 that is the competition.
I'm not totally agree. Not so simple...
But if I remember well, the noise of SDS at full BW (5mV) is under 1mV. At the beginning when the noise gnd is very high (160-200mV) I couldn't to examine a signal with a few mV, it was full with artifacts and not stable - only with my old analoge Hameg I could.
Today with my mods (I have a noise gnd 40-55mV peak to peak) there is no any difference between Hameg and Owon in signals with a few mV, very stable and clearly.
I'm not complaining about this: "the noise of SDS at full BW (5mV) is under 1mV". This is acceptable. ;)
This is what bothers me: "when the noise gnd is very high (160-200mV)". Or "a noise gnd 40-55mV peak to peak".
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Your mystery is like "Mitos of Ariadnes" (from Greek Mythology) same psu, identical adapter but the noise is differente, but remaining the answer of Flash2light what is marking of U2 in ver. 3.3. Probably, there is a difference there...
Well that's not too bad, I'll be more scared to look around for the answer if it resembled the story of Medusa, it wouldn't be cool turning to stone.
...
Tomc: Is the difference between yours and these very marked?
I get 60-70mVpp, which is better than what I had before (about 150mVpp). The disappointing part is that with the old PSU board, after adding some ferrites to the interconnecting cables, I had as good or better results than with the new PSU. However, as it is now, I can work a lot better with low level signals at full bandwidth. For example, I can easily trigger on a 50mVpp signal. When I had 150mVpp noise that was impossible unless I used the short ground clip.
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Your mystery is like "Mitos of Ariadnes" (from Greek Mythology) same psu, identical adapter but the noise is differente, but remaining the answer of Flash2light what is marking of U2 in ver. 3.3. Probably, there is a difference there...
Well that's not too bad, I'll be more scared to look around for the answer if it resembled the story of Medusa, it wouldn't be cool turning to stone.
There are a couple of things I've been thinking about. I took a real good look at my new PSU board and discovered that one of the new decoupling capacitors is probably missing. There is no capacitor where C23 is supposed to be. C23 is supposed to be at the end of the adapter board connector. I see glue residue, as if the component was there but fell off during the soldering process. However, I don't think this would cause such a big difference in noise by itself.
Flash2light, can you tell me if this capacitor is present on your PSU board?
The other thing I've been thinking about is that I don't have the battery option. With a battery installed you have additional filtering for the 8.4V supply. The battery itself can act as a super capacitor. I don't know for sure if the results from dgmoore78@yahoo.com and Flash2light were obtained with the optional battery installed.
dgmoore78@yahoo.com and Flash2light, can you clarify this, and if possible, if your test was done with the battery installed, can you do the test again without the battery?
C23 has been removed.
Noise measured without the battery.
Battery measured noise is nearly the same.
If a test lead is straight. The noise increases. "The use of the battery 40mV" picture!
"if test lead move close to the psu or display. noise will increase."
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It is known that if you straight the cable of probe you'll catch everything because the cable of probe will work like antenna and the noise will increased.
For this reason and for comparison reasons, we have suggest to all member to make the measurement having 2 cycles of cable fixed on the table.
In other case there will be a significant range of deviation on our measurements without accuracy between trials.
Normally, if we to do with more accuracy it should to have 3 measurements
Without any battery inside with power by ac
With battery inside but power by ac
With battery inside and power with this.
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Reducing the ground loop area, should reduce the noise induced in the.
I do not understand why they have not shielded it internally...
Why not you try to cover the wire of the probe with aluminum foil, seeking a Faraday cage.
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filtering ripple as much as possible.
After this, the protection of every inductors farad cage.
The battery needs to pass the filter.
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https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/msg248589/#msg248589 (https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/msg248589/#msg248589)
Tektronix TDS210 oscilloscope inside photos:
(https://www.eevblog.com/forum/testgear/tektronix-tds210-oscilloscope-inside-photos/?action=dlattach;attach=57225)
(https://www.eevblog.com/forum/index.php?action=dlattach;topic=19576.0;attach=57228;image)
This finish is similar to that used in laptops. Conductive paint ready to spray... Where is it sold?
http://www.xsf168.com/en/About.asp (http://www.xsf168.com/en/About.asp)
http://www.mgchemicals.com/products/protective-coatings/emi-rfi-shielding/super-shield-silver-copper-843/ (http://www.mgchemicals.com/products/protective-coatings/emi-rfi-shielding/super-shield-silver-copper-843/)
http://uk.farnell.com/kontakt-chemie/emi-35-200ml/coating-conductive-emi-35-200ml/dp/2142398 (http://uk.farnell.com/kontakt-chemie/emi-35-200ml/coating-conductive-emi-35-200ml/dp/2142398)
http://es.farnell.com/electrolube/enscp400h/coating-nickel-can-400ml/dp/1675347?crosssellid=1675347&crosssell=true&in_merch=true& (http://es.farnell.com/electrolube/enscp400h/coating-nickel-can-400ml/dp/1675347?crosssellid=1675347&crosssell=true&in_merch=true&)
http://www.caswellplating.com/copper-conductive-paint-4oz.html (http://www.caswellplating.com/copper-conductive-paint-4oz.html)
...
By the way the TDS210 reaches up to 180 Wfmr/s.
http://www.chipdip.ru/en/video/id000276002/ (http://www.chipdip.ru/en/video/id000276002/)
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Carrington, in my country we say "you get that you paid" (I don't know if there is meaning in english something.
The price of this oscilloscope when it was "young" was over 1500 euros.
But I agree totally with you, fine workmanship inside.
I think in past the TomC searched about this material like your links, I don't know if he found something, but the spray shield coating....yes they like me very well...
The ground noise is not legacy of Owon. Eight years old Tektronics you had more gnd noise that the initial SDS gnd noise. But I haven't any other experience with digital oscilloscopes only with analogues.
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C23 has been removed.
Noise measured without the battery.
Battery measured noise is nearly the same.
If a test lead is straight. The noise increases. "The use of the battery 40mV" picture!
"if test lead move close to the psu or display. noise will increase."
Thanks, for the info and the test, that clears up the C23 mystery and shows the battery has some influence on the GND noise. I think I'm going to try some additional electrolytic capacitors to make up for the lack of a battery on my scope. I'll post the results if it makes a difference.
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Reducing the ground loop area, should reduce the noise induced in the.
I do not understand why they have not shielded it internally...
Why not you try to cover the wire of the probe with aluminum foil, seeking a Faraday cage.
I've tried that, but didn't have that much of an effect, you have to ground the aluminum foil for it to make a little bit of a difference, and that's not that practical. The best way I've found to prevent the scope radiation from affecting the GND noise ( when the probe cable is close to the screen) is to loop the probe cable through a couple of large ferrites. One at each end of the cable.
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Carrington, in my country we say "you get that you paid" (I don't know if there is meaning in english something.
The price of this oscilloscope when it was "young" was over 1500 euros.
But I agree totally with you, fine workmanship inside.
I think in past the TomC searched about this material like your links, I don't know if he found something, but the spray shield coating....yes they like me very well...
The ground noise is not legacy of Owon. Eight years old Tektronics you had more gnd noise that the initial SDS gnd noise. But I haven't any other experience with digital oscilloscopes only with analogues.
I sort of gave up on that approach because you also have to make sure the finish is grounded, otherwise the whole cabinet becomes an antenna. I addition, even if you get that right, you still have the radiation coming through the screen itself, which is the most powerful one. There is a transparent shielding material that can be used on the screen, but I wasn't able to find a source that sells it in small quantities at a reasonable price. For now the small ferrite that I put on the cable going to the TFT LED's reduces the radiation enough for the times I get the probe cable close to the screen.
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Carrington, in my country we say "you get that you paid" (I don't know if there is meaning in english something.
The price of this oscilloscope when it was "young" was over 1500 euros.
But I agree totally with you, fine workmanship inside.
I think in past the TomC searched about this material like your links, I don't know if he found something, but the spray shield coating....yes they like me very well...
The ground noise is not legacy of Owon. Eight years old Tektronics you had more gnd noise that the initial SDS gnd noise. But I haven't any other experience with digital oscilloscopes only with analogues.
"You get what you pay for" is what they say over here, very similar!
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Well I have already purchased this: http://uk.farnell.com/kontakt-chemie/emi-35-200ml/coating-conductive-emi-35-200ml/dp/2142398 (http://uk.farnell.com/kontakt-chemie/emi-35-200ml/coating-conductive-emi-35-200ml/dp/2142398)
I will show the results, when I have everything ready, I hope that Aidetek keep his word.
I could use an antistatic bag, only to test.
http://www.hollandshielding.com/226-Transparent_foil-en.htm (http://www.hollandshielding.com/226-Transparent_foil-en.htm)
But the ferrite in the flat cable of the TFT eliminates much noise.
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Well I have already purchased this: http://uk.farnell.com/kontakt-chemie/emi-35-200ml/coating-conductive-emi-35-200ml/dp/2142398 (http://uk.farnell.com/kontakt-chemie/emi-35-200ml/coating-conductive-emi-35-200ml/dp/2142398)
I will show the results, when I have everything ready, I hope that Aidetek keep his word.
I could use an antistatic bag, only to test.
http://www.hollandshielding.com/226-Transparent_foil-en.htm (http://www.hollandshielding.com/226-Transparent_foil-en.htm)
But the ferrite in the flat cable of the TFT eliminates much noise.
Carrington, the flat cable ferrite came with my scope, I don't know what the effect is if it's not there. The ferrite I was talking about is on the 2 wire cable from the adapter to the TFT backlight LED's. You can't see the ferrite itself on the photo because it's inside the blue shrink tubing.
-
Your mystery is like "Mitos of Ariadnes" (from Greek Mythology) same psu, identical adapter but the noise is differente, but remaining the answer of Flash2light what is marking of U2 in ver. 3.3. Probably, there is a difference there...
Well that's not too bad, I'll be more scared to look around for the answer if it resembled the story of Medusa, it wouldn't be cool turning to stone.
There are a couple of things I've been thinking about. I took a real good look at my new PSU board and discovered that one of the new decoupling capacitors is probably missing. There is no capacitor where C23 is supposed to be. C23 is supposed to be at the end of the adapter board connector. I see glue residue, as if the component was there but fell off during the soldering process. However, I don't think this would cause such a big difference in noise by itself.
Flash2light, can you tell me if this capacitor is present on your PSU board?
The other thing I've been thinking about is that I don't have the battery option. With a battery installed you have additional filtering for the 8.4V supply. The battery itself can act as a super capacitor. I don't know for sure if the results from dgmoore78@yahoo.com and Flash2light were obtained with the optional battery installed.
dgmoore78@yahoo.com and Flash2light, can you clarify this, and if possible, if your test was done with the battery installed, can you do the test again without the battery?
C23 has been removed.
Noise measured without the battery.
Battery measured noise is nearly the same.
If a test lead is straight. The noise increases. "The use of the battery 40mV" picture!
"if test lead move close to the psu or display. noise will increase."
Flash2light, when I first looked at your post I assumed that the photo was showing the noise with the scope powered by the grid and the battery removed. However, after looking at the photo closely it seems that the Power ON LED is off. That tells me that you were running the scope off the grid on battery power alone. Is that right?
So now I think that when you say: Noise measured without the battery. Battery measured noise is nearly the same.
It means that the 24mVpp noise photo on you previous post was taken with the scope powered by the grid and the battery removed, and that the noise is nearly the same if the scope is powered by the grid and the battery is installed. Did I get it right this time?
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Carrington, the flat cable ferrite came with my scope, I don't know what the effect is if it's not there. The ferrite I was talking about is on the 2 wire cable from the adapter to the TFT backlight LED's. You can't see the ferrite itself on the photo because it's inside the blue shrink tubing.
Mine does not have that ferrite. :--
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Carrington, the flat cable ferrite came with my scope, I don't know what the effect is if it's not there. The ferrite I was talking about is on the 2 wire cable from the adapter to the TFT backlight LED's. You can't see the ferrite itself on the photo because it's inside the blue shrink tubing.
Mine does not have that ferrite. :--
Yeah, I suspected that because you have the version 3.0 adapter, I think the flat ferrite was installed by Owon when they released the version 3.2 adapter. Maybe you can contact Aidatek and see if you can get the ferrite along with your new PSU and Adapter boards. I've also seen some flat ferrites at Digi-key, I'm not sure if they have one the right size, but it wouldn't hurt to check. Good luck!
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Oh, I left some hours the forum and you have writing a lot of... :)
The C23 has been removed.
You can try to put one and see what happens, mine psu (mod) I have put a smd capacitor to this place.
TomC if you wanna to change some electrolytic capacitors look at my post that I had changed all the electrolytic caps and I had a good result to all spikes! (page 87, post 1302
We are to the right road...Carrington will try the EMI spray, TomC search for a transparent shielding material that can be used on the screen...fine!
TomC to mine if I put a small ferrite on the cable going to the TFT LED's there is no any reduces at the radiation, perhaps the various decoupling at the Led Drive Circuit works and ferrite can't to help any more.
"You get what you pay for" is what that I say...thanks TomC the forum isnt' technical support only but including and english teaching!
Carrington don't worry about flat ferrite and mine there isn't this flat ferrite inside. Probably they adding this ferrite from adapter ver. 3.2 and then.
Perhaps some member removed this ferrite to see if works or it is for decorating purpose!
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TomC to mine if I put a small ferrite on the cable going to the TFT LED's there is no any reduces at the radiation, perhaps the various decoupling at the Led Drive Circuit works and ferrite can't to help any more.
That's probably what it is, the TFT backlight circuit is what's producing some of the noise radiating from the screen, the small ferrite filters some of that. But if you have already used bypass capacitors is like the ferrite on the PSU to adapter, it doesn't help very much once you have used bypass capacitors to filter much of the PSU noise.
I was thinking of using electrolytic capacitors to take the place of the battery, but from Flash2light post, if I read it correctly, the battery in or out doesn't make much of a difference. So that idea may not be so good after all.
Right now I'm starting to put the scope back together, since I had it open anyway I took some time to look around for any obvious blunders. I didn't find anything significant, just going to make sure that all the screws to the Z plate are tight and making good connection with the pads on the boards.
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Your mystery is like "Mitos of Ariadnes" (from Greek Mythology) same psu, identical adapter but the noise is differente, but remaining the answer of Flash2light what is marking of U2 in ver. 3.3. Probably, there is a difference there...
Well that's not too bad, I'll be more scared to look around for the answer if it resembled the story of Medusa, it wouldn't be cool turning to stone.
There are a couple of things I've been thinking about. I took a real good look at my new PSU board and discovered that one of the new decoupling capacitors is probably missing. There is no capacitor where C23 is supposed to be. C23 is supposed to be at the end of the adapter board connector. I see glue residue, as if the component was there but fell off during the soldering process. However, I don't think this would cause such a big difference in noise by itself.
Flash2light, can you tell me if this capacitor is present on your PSU board?
The other thing I've been thinking about is that I don't have the battery option. With a battery installed you have additional filtering for the 8.4V supply. The battery itself can act as a super capacitor. I don't know for sure if the results from dgmoore78@yahoo.com and Flash2light were obtained with the optional battery installed.
dgmoore78@yahoo.com and Flash2light, can you clarify this, and if possible, if your test was done with the battery installed, can you do the test again without the battery?
C23 has been removed.
Noise measured without the battery.
Battery measured noise is nearly the same.
If a test lead is straight. The noise increases. "The use of the battery 40mV" picture!
"if test lead move close to the psu or display. noise will increase."
Flash2light, when I first looked at your post I assumed that the photo was showing the noise with the scope powered by the grid and the battery removed. However, after looking at the photo closely it seems that the Power ON LED is off. That tells me that you were running the scope off the grid on battery power alone. Is that right?
So now I think that when you say: Noise measured without the battery. Battery measured noise is nearly the same.
It means that the 24mVpp noise photo on you previous post was taken with the scope powered by the grid and the battery removed, and that the noise is nearly the same if the scope is powered by the grid and the battery is installed. Did I get it right this time?
-Powered by grid and battery not installed: noise about 30mvpp
-Powered by battery and grid not installed: noise about 30mvpp
But if the test lead is straight. noise increases more; battery use.
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-Powered by grid and battery not installed: noise about 30mvpp
-Powered by battery and grid not installed: noise about 30mvpp
But if the test lead is straight. noise increases more; battery use.
Thanks for clarifying that.
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This is ver 3.3 dc-dc board under side.
That's identical to mine (3.2), but yours had the smd capacitor under C34 installed at the factory.
Flash2light, can you read the markings on U2 on your board, on mine I see OBT 2?K CX10. The question mark is a character that I can't make out.
This is new photo lcd backlight dc-dc chip.
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After putting the scope back together my ground noise results have improved. I don't have a definite explanation for this but I did a couple of things that may have had some influence.
1. I cleaned the flux residue from the PSU board with Radio Shack electronics cleaner. In general it wasn't too bad originally, but a couple of areas had a thick coating.
2. I cleaned the pads that contact the Z plane on both the PSU and the adapter board and made sure that the screws were tightly secured.
Before snapping the cabinet back together I tried connecting a 3300 microfarad electrolytic where the battery would be normally connected. It didn't make much of a difference on the GND noise.
When I connected the laptop to the scope to capture some waveform images, I noticed that the noise jumped about 10mVpp. In the past the noise was high enough that I didn't realize this had an effect. So I put a ferrite on the USB cable to help this. Still, the noise in the attachments is about 2mVpp higher than what I observed when there was no USB cable connected.
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This is ver 3.3 dc-dc board under side.
That's identical to mine (3.2), but yours had the smd capacitor under C34 installed at the factory.
Flash2light, can you read the markings on U2 on your board, on mine I see OBT 2?K CX10. The question mark is a character that I can't make out.
This is new photo lcd backlight dc-dc chip.
That's a very nice and clear photograph, Thanks.
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I quote some older post about how was the noise related with the battery option or not.
There was differente results between me and rf-loop.
Now after my mods there is no any significant difference between battery or ac plug.
Unfortunately, mine situation is different from what we are expected!
With well charged battery from the worst to best the sequence is: battery (?400mV), battery+ac main(?300mV), ac main (?150mV) - Cheked by Owon Probe after Self Cal procedure and Probe adjustment.
Yes, this is unexpected result.
I have seen before:
(a) battery+ac most bad,
(b) ac without installed battery (battery out) less than a
(c) with battery alone without ac connected, less than b
It need some more investigation. I have some small suspects but too early to say.
Thanks Flash2light for this sharp photo.
TomC, you have a lot of improvement.
This was you have done after the psu changed and adapter mode, 68mV peak to peak and now you are 36mV about:
(https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/?action=dlattach;attach=53708;image)
But I have some of questions-observations
1) you have different time set, the first was 1ms and now is 500us, normally there is no significant difference but if there is a periodic noise, the time makes the difference.
2) The back cover was closed at the two measurement of noise or they was different? Perhaps, this changed the noise.
3) some times the residues decrease the electricity of components. Personally, I have see some difference to noise after a good bath and very well drying with isopropylic alchool.
4) what you meaning with "Base line noise", from what I see there is no any BW limited or something else.
But please to all member, let us make measurements with same conditions like a protocol.
I copy the directions of rf-loop for comparisons reasons:
Procedure for measurent of GND Noise
----------------------------------------------------
Make a Calibration procedure as manual refer (there is no nessesary if not the temperature variables ±5°C from the initial calibration)
Compensate the probe as manual described.
Change switch probe to 10x and set the same to the Probe Owon Menu (10X).
Connect together the probe tip and the probe aligator ground to Probe Comp GND.
Fix the cable of probe like the attachment photo.
Turn CH2 off.
CH1 to DC, 50mV/Div.
Push Trigger 50%
Set the Acquire Length to 1M and the Acqu. Mode to Peak
Set the Horizontal speed to 100us
Set the measurement to Voltage peak to peak (Vp to Owon) and write the value.
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But I have some of questions-observations
1) you have different time set, the first was 1ms and now is 500us, normally there is no significant difference but if there is a periodic noise, the time makes the difference.
2) The back cover was closed at the two measurement of noise or they was different? Perhaps, this changed the noise.
3) some times the residues decrease the electricity of components. Personally, I have see some difference to noise after a good bath and very well drying with isopropylic alchool.
4) what you meaning with "Base line noise", from what I see there is no any BW limited or something else.
But please to all member, let us make measurements with same conditions like a protocol.
I copy the directions of rf-loop for comparisons reasons:
Procedure for measurent of GND Noise
----------------------------------------------------
Make a Calibration procedure as manual refer (there is no nessesary if not the temperature variables ±5°C from the initial calibration)
Compensate the probe as manual described.
Change switch probe to 10x and set the same to the Probe Owon Menu (10X).
Connect together the probe tip and the probe aligator ground to Probe Comp GND.
Fix the cable of probe like the attachment photo.
Turn CH2 off.
CH1 to DC, 50mV/Div.
Push Trigger 50%
Set the Acquire Length to 1M and the Acqu. Mode to Peak
Set the Horizontal speed to 100us
Set the measurement to Voltage peak to peak (Vp to Owon) and write the value.
The measurements were made with the scope completely back together (back cover closed etc.)
The baseline attachment is the noise when nothing is attached to the BNCs (no probes). Sometimes called baseline because it's supposedly what you start with, independent of ground noise for example.
The time base 500micro seconds or 1ms don't make much difference, but the trigger does. What I found is that with this low noise level, auto trigger with CH1 source is sporadic while it tries to adjust to noise spikes etc. You end up capturing something that is not the average. I suggest using AC line source for a more stable trigger.
Also, when you capture in peak detect mode, the capture length is always 10M. However if you do captures on other modes, you should set to 10M manually to make sure you capture all the noise. Try it and you'll see it makes a difference.
I prefer Average mode to get a more realistic picture of how the noise is going to affect your use of the scope when viewing real life waveforms. I use average 16 so it doesn't take too long to stabilize. Peak detect mode gives a snapshot of what's happening in the instant you do the capture, as far as the highest noise levels are, but these transients are not a good prediction of performance when you are using the scope normally. So I would like to see more people posting their average noise, if possible.
Got to go, it's lawn mowing day!
Edit: The capture length is not 10M, however, if you forget to set the length to 10M, the noise reading will be almost if not equally as accurate as if you had. The reason is that on peak-detect mode the scope first selects and keeps the lowest and highest samples, then throws away other excess samples so that the image fits in the memory length that has been selected.
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Also, when you capture in peak detect mode, the capture length is always 10M.
Really?
Afaik, not.
Peak mode do not have so much advantage if scope use one channel 1GSa/s or two channel 500MSa/s.
As we know if one channel in use ADC run allways 1x 1GSa/s mode and if 2 channel in use 2x500MSa/s mode. This is independent of time base setting of course. If example selected one channel and 1k memory and 500us/div there read 100kSa/s. But system run 1GSa/s. But it collect to 1k sampling buffer only every 10000th of sample and do not care about these other samples at all. Simplified: In peak mode it is not blind when it drops out these 9999 samples and keep one.. it find highest value and lowest value there.. (becouse still 100kSa/s there is now sequentially ...highest, lowest, highest... after every 10us.)
I do not know how it exactly then build displayed image etc details so there may be some tiny differencies if use 1GSa normal mode or slower but peak mode. In practice not much.
Set 1k memory, 500us/div, peak and display mode dots.
capture just something noisy.
Stop scope. Zoom out ti 1ms/div you see there is 10div
Zoom in to 10us/div. Count sample points... there is 1000
Same but acquire mode normal.
Count sample points, there is 1000.
;)
(nosignal5mVpeak1k.bin.txt) remove .txt
There is 1000 sample points.
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...
The baseline attachment is the noise when nothing is attached to the BNCs (no probes). Sometimes called baseline because it's supposedly what you start with, independent of ground noise for example.
...
Got to go, it's lawn mowing day!
Thanks for explaination TomC, but seems like crazy to me a 10mV base line, normaly should to was to 1mV.
Look, at the last capture that rf-loop upload at the 5mV. The base line noise is 1mV (full BW like yours).
(http://t3.gstatic.com/images?q=tbn:ANd9GcTnvF4wSb3hZqEPtUXhiJR85iYObVEwiFx9ipmJYgZCavLZjYaP3Q)
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Also, when you capture in peak detect mode, the capture length is always 10M.
Really?
Afaik, not.
Peak mode do not have so much advantage if scope use one channel 1GSa/s or two channel 500MSa/s.
As we know if one channel in use ADC run allways 1x 1GSa/s mode and if 2 channel in use 2x500MSa/s mode. This is independent of time base setting of course. If example selected one channel and 1k memory and 500us/div there read 100kSa/s. But system run 1GSa/s. But it collect to 1k sampling buffer only every 10000th of sample and do not care about these other samples at all. Simplified: In peak mode it is not blind when it drops out these 9999 samples and keep one.. it find highest value and lowest value there.. (becouse still 100kSa/s there is now sequentially ...highest, lowest, highest... after every 10us.)
I do not know how it exactly then build displayed image etc details so there may be some tiny differencies if use 1GSa normal mode or slower but peak mode. In practice not much.
Set 1k memory, 500us/div, peak and display mode dots.
capture just something noisy.
Stop scope. Zoom out ti 1ms/div you see there is 10div
Zoom in to 10us/div. Count sample points... there is 1000
Same but acquire mode normal.
Count sample points, there is 1000.
;)
(nosignal5mVpeak1k.bin.txt) remove .txt
There is 1000 sample points.
You are right rf-loop. What I meant to say is that on peak detect mode you capture just the highs and lows of the signal and ignore everything else, so the noise reading is pretty much the same even if you forget to set the length to 10M. I was in a hurry and tried to shorten what I was writing and it came out misleading. Thanks for pointing it out :-+
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...
The baseline attachment is the noise when nothing is attached to the BNCs (no probes). Sometimes called baseline because it's supposedly what you start with, independent of ground noise for example.
...
Got to go, it's lawn mowing day!
Thanks for explaination TomC, but seems like crazy to me a 10mV base line, normaly should to was to 1mV.
Look, at the last capture that rf-loop upload at the 5mV. The base line noise is 1mV (full BW like yours).
(http://t3.gstatic.com/images?q=tbn:ANd9GcTnvF4wSb3hZqEPtUXhiJR85iYObVEwiFx9ipmJYgZCavLZjYaP3Q)
Lemon, it is 1mV, but the probe setting is set to x10, I didn't bother to change it, so the scope multiplies by 10 whatever it thinks is coming from the BNC.
I got done mowing about an hour ago and had to take a rest :=\
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Here is a little more information on peak detect mode. May help clarify the last few posts on that subject. ;)
The entire article in PDF is also attached.
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After a lot of tinkering, prodding Owon to come up with solutions, and some major modifications, the GND noise level of several of our scopes is down to under 50mVpp. It also seems that members that bought their scopes recently are getting decent GND noise levels right out of the box.
For me, the GND noise level was never a deal breaker, but rather like a nagging little gnat that you can't swat no matter how hard you try. It can't hurt you, but you'll go to considerable lengths to get rid of it.
Now that the GND noise level of my scope is in the mid thirties of mVpp, I wanted to see how this improvement would potentially affect the way I use the scope. One of the main reasons for wanting a low GND noise level is to make it possible to view and trigger on low level signals while still enjoying the convenience of using the long ground lead.
The attached captures show the lowest level signals that allow my scope to properly trigger and consistently display the correct trigger frequency. It is possible to obtain a stable trigger at lower amplitudes, but the trigger frequency displayed is not correct. The threshold where this transition occurs in my scope is around 36-38mVpp.
I obtained images with both the long ground lead and the ground clip. The signal generator was set to the lowest level that allowed the correct trigger frequency to be displayed while using the long ground lead. Then the ground clip was used to capture the same signal without altering the signal generator setting. At low frequencies the two images are almost identical. At higher frequencies the effect of the long ground lead inductance starts to become apparent. At 30MHz the amplitude of the two images is several millivolts apart. The higher amplitude obtained with the long ground lead. Perhaps is not such a good idea to use the long ground lead much beyond this frequency if accurate readings are needed.
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TomC had you measure before changes what was the threshold for right triggering?
I think that these measures (noise + triggering) there is no way to obtain with the old psu board?
I hadn't test before to my scope the level for right triggering but with very low signals there is no way to examined because noise.
There is some documentation here (http://owon.forumup.com/viewtopic.php?t=177&mforum=owon) (it demands login to see the captures) about before and after mods. With noisy gnd and long ground clip 50mVpp square signals there is no way to examined, after mods 1MHz/2mVrms sinus signal is almost perfect with a long gnd clip. But there is no reference about triggering.
It is interesting if other members have some tests before and after and specialy triggering operation.
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Hi there guys!
I decided to do some experimenting with ground noise problems, since it seems that I have a particularly "interesting" unit. I have a "thick" part of noise which is around 300 mV peak to peak and some huge spikes which are between 2 V and 3 V (even worse with 150 MHz probes I'm normally using). Their period is around 80 ms. I have an older through-hole version of the power supply marked PCB-T115-J rev4 and 3.0 adapter. From time to time, there will be a huge single peak of 5 V to 6 V as well. One interesting thing is that this PSU is using the "Z-plate" as heatsink for D8.
To get to the source of the noise I connected one probe to the ground pin on the probe compensation connector and moved the other probe around the power supply. From what I can see, most of the peaks seem to be synchronized to the waveform on the coil marked L2. Unfortunately, my power supply does not have coil L3 (which from what I can see if used as a filter) and instead seems to be filtered only with an electrolytic capacitor. I placed two 100 nF 1206 SMD capacitors and two 47 nF 0805 SMD capacitors over the electrolytic. In addition to that, near the power connector there were unpopulated places for ceramic through-hole capacitor and for one electrolytic capacitor on the -7.6 V rail. I placed one 470 µF capacitor and one 100 nF disk ceramic capacitor at the power connector. In addition to that, I placed same set of 4 SMD capacitors in parallel to the electrolytic.
Next, I added two 100 nF 1206 SMD capacitors in parallel with all electrolytic capacitors on the secondary side of the power supply. I also replaced the 1N4007 diodes mentioned few pages back with UF4007, but in my case that made no measurable improvement. My guess is that the reason for that is the large amount of noise that is cancelling all the (minor) improvements I made.
As you can probably guess, I'm poking in the dark here trying to come up with something that would help. My next plan is to get some 1 µF 1206 and 0805 SMD capacitors and place them in parallel with the ones I already have on the -7.6 V rail.
First attached image is how everything looked like with only ferrite on the power cable going from the PSU to the adapter board. Next two images are made after adding the capacitors on the -7.6 V rail and show relationship between the noise peaks and the waveform on L2. Final image is what I get when I use same settings as on the first image. Unfortunately, there seems to be no improvement (in fact I could say it's a bit worse now).
So does anyone have any smart ideas what to try now? I'm starting to run out of ideas and am considering undoing the changes I made since I don't actually have any problems running the scope for my needs. It's just that knowing that the ground noise is there is bugging me.
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AndrejaKo you have the most :palm: psu board that I have seen!
Can you upload the two faces photos of this board? One for components and one for soldering routing.
I have a through-hole version also but it doen't use the Z-plate as heatsink for D8.
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I have a through-hole version also but it doen't use the Z-plate as heatsink for D8.
It was in very first versions and if there is also this totally different front end electromechanical construction then scope is perhaps this very extremely early version.
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I have seen that noise while waving USB cables and HUB close to the scope.
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I have an older through-hole version of the power supply marked PCB-T115-J rev4 and 3.0 adapter.
You can make a picture and upload it to the forum.
Thanks. :)
If the adapter is similar to the following link. Could you try to make the mod. indicated?
https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/msg265881/#msg265881 (https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/msg265881/#msg265881)
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It was in very first versions and if there is also this totally different front end electromechanical construction then scope is perhaps this very extremely early version.
Sure sure, that explains everything...
AndrejaKo: Why you bought one of the first? Very bad, very bad...
I still wonder why I buy one ~7 months ago. :-DD
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Well the scope's serial number is SDS71021211XXX (came with 2.6.2 firmware if I remember correctly) and the main board, which has been replaced, is SDS71021209XXX. I got it in June 2012. It seemed like a good idea at the moment.
Anyway, I can't post pictures right now, since I don't have a digital camera at the moment and I assure you that you do not want to see photographs from my smartphone. I'm working on obtaining a camera, so hopefully by the end of the day, I'll be able to post pictures.
Also I must say that my computer is relatively close to the scope, so I'll take one more batch of screenshots in an empty room, just to be 100% sure that the noise isn't external.
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11th week of 2012 is somewhere at the end of April.
If I remeber well, before this period the Owon had done some major changes to the hw. No you haven't the early version of this scope but you have a bbbbaaadddllllyyyy psu board!
If you can't upload photos, you can find some helping for TomC's psu diagram circuit (it is based on an newer version with smd IC) and if you wish I can to upload some photos from mine version. I don't know perhaps to help they to some mods.
But it is very strange to me to have such a lot of noise with ferrite to carbon cable between psu and adaptor boards. If you used a large ferrite and you have a such noise perhaps this psu board is for trash! There is no way to pass the EMI Standards!
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Hi there guys!
I decided to do some experimenting with ground noise problems, since it seems that I have a particularly "interesting" unit. I have a "thick" part of noise which is around 300 mV peak to peak and some huge spikes which are between 2 V and 3 V (even worse with 150 MHz probes I'm normally using). Their period is around 80 ms. I have an older through-hole version of the power supply marked PCB-T115-J rev4 and 3.0 adapter. From time to time, there will be a huge single peak of 5 V to 6 V as well. One interesting thing is that this PSU is using the "Z-plate" as heatsink for D8.
To get to the source of the noise I connected one probe to the ground pin on the probe compensation connector and moved the other probe around the power supply. From what I can see, most of the peaks seem to be synchronized to the waveform on the coil marked L2. Unfortunately, my power supply does not have coil L3 (which from what I can see if used as a filter) and instead seems to be filtered only with an electrolytic capacitor. I placed two 100 nF 1206 SMD capacitors and two 47 nF 0805 SMD capacitors over the electrolytic. In addition to that, near the power connector there were unpopulated places for ceramic through-hole capacitor and for one electrolytic capacitor on the -7.6 V rail. I placed one 470 µF capacitor and one 100 nF disk ceramic capacitor at the power connector. In addition to that, I placed same set of 4 SMD capacitors in parallel to the electrolytic.
Next, I added two 100 nF 1206 SMD capacitors in parallel with all electrolytic capacitors on the secondary side of the power supply. I also replaced the 1N4007 diodes mentioned few pages back with UF4007, but in my case that made no measurable improvement. My guess is that the reason for that is the large amount of noise that is cancelling all the (minor) improvements I made.
As you can probably guess, I'm poking in the dark here trying to come up with something that would help. My next plan is to get some 1 µF 1206 and 0805 SMD capacitors and place them in parallel with the ones I already have on the -7.6 V rail.
First attached image is how everything looked like with only ferrite on the power cable going from the PSU to the adapter board. Next two images are made after adding the capacitors on the -7.6 V rail and show relationship between the noise peaks and the waveform on L2. Final image is what I get when I use same settings as on the first image. Unfortunately, there seems to be no improvement (in fact I could say it's a bit worse now).
So does anyone have any smart ideas what to try now? I'm starting to run out of ideas and am considering undoing the changes I made since I don't actually have any problems running the scope for my needs. It's just that knowing that the ground noise is there is bugging me.
AndrejaKo, Since you have all that noise around L2, I would check C9, C10 and C11 out of the circuit and replace them if necessary. The amount of noise you have seems more like a malfunction than ground noise. Just a thought!
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AndrejaKo, Since you have all that noise around L2, I would check C9 and C11 out of the circuit and replace them if necessary. The amount of noise you have seems more like a malfunction than ground noise. Just a thought!
The truth is that yes, it seems something like that.
Maybe rf-loop has seen something like this before.
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TomC had you measure before changes what was the threshold for right triggering?
I think that these measures (noise + triggering) there is no way to obtain with the old psu board?
I hadn't test before to my scope the level for right triggering but with very low signals there is no way to examined because noise.
There is some documentation here (http://owon.forumup.com/viewtopic.php?t=177&mforum=owon) (it demand login to see the captures) about before and after mods. With noisy gnd and long ground clip 50mVpp square signals there is no way to examined, after mods 1MHz/2mVrms sinus signal is almost perfect with a long gnd clip. But there is no reference about triggering.
It is interesting if other members have some tests before and after and specialy triggering operation.
I have checked this before the mods, unfortunately I didn't document it, wish I had! Relying strictly on memory, I don't think I had any luck with amplitudes below 75-100mVpp. I also remember that the waveforms with the long ground lead were distorted compared to the ground clip, specially at the lower frequencies where the density of the noise spikes is higher.
I'm also a member of ForumUp, I don't think I posted anything there yet, but I'm pretty sure I've seen some of your posts, and of course rf-loop's (aghp in that forum).
I would also like to see other members post their results for similar tests. After all, I think this is more telling of the scope's performance than just the GND noise test.
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AndrejaKo, Since you have all that noise around L2, I would check C9, C10 and C11 out of the circuit and replace them if necessary. The amount of noise you have seems more like a malfunction than ground noise. Just a thought!
I would also check, R8 and C7, the snubber for D4.
By the way, the components I mentioned in both posts are referenced to the schematic in the Service Manual, which is a thru hole version similar to what you have. I attached a copy in case you don't have it.
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AndrejaKo, don't forget to have in memo the following procedure.
Procedure for measurement of GND Noise
----------------------------------------------------
Make a Calibration procedure as manual refer (there is no nessesary if not the temperature variables ±5°C from the initial calibration)
Compensate the probe as manual described.
Change switch probe to 10x and set the same to the Probe Owon Menu (10X).
Connect together the probe tip and the probe aligator ground to Probe Comp GND.
Fix the cable of probe like the attachment photo.
Turn CH2 off.
CH1 to DC, 50mV/Div.
Push Trigger 50%
Set the Acquire Length to 1M and the Acqu. Mode to Peak
Set the Horizontal speed to 100us
Set the measurement to Voltage peak to peak (Vp to Owon) and write the value.
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First, sorry for the confusion. My readings were made using battery only! Next, my L2 is L3 on this new schematic and is same as L2 on TomC's reverse-engineered schematic! It's the coil used by the MC34063A to generate negative voltage. Compared to the new schematic, some components are missing on my board. First, there was only one green 470 µF 16 V electrolytic capacitor right next to the IC. There are (originally unpopulated) foorprints for another electrolytic and ceramic capacitors next to the connector.
Anyway, I found components that to me look like the snubber for the diode (but I didn't use that, since power is coming from the battery, right?). They are marked C4 and R11. C4 shows 2.287 nF, which is pretty close to expected value, from what I can see. R11 gives 21.7 ohm reading on my multimeter, so that too looks OK. The soldering of R11 was bad in my opinion, so resoldered it.
My problem with the capacitors is that I don' have an ESR tester at the moment and my multimeters can't measure large electrolytic capacitors. I'm making a crappy one from schematics of an old Poptronix kit, so maybe that will help and maybe not.
As for the ferrite, I'll post a picture of it when I get a camera. It's about the size posted maybe 20 pages back.
I'm off to get a camera now, so hopefully my next post will have photos of the PSU itself. Thanks for all the ideas!
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@ AndrejaKo = I'll upload mine psu board PCB-T115-J rev6, probably will be help you a more becouse they differs only by revision.
From the forum of Electronics and Owon SmartDS oscilloscopes have the information that now all the new SDS have a probe gnd short as accessoires.
I have made mine by diy method...
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@ AndrejaKo = about ESR of electrolytic capacitors on psu board.
First, I have the same concern about what values have they. If you will see at my older post I changed them with Nippon NCC KY Series (same uF/V) with a low ESR.
When I take off chinesse capacitors and measure ESR them, they had a very low ESR!
But the new ones had better behaviour at filtering to high peaks of noise. See my post 1302 at page 87 how they filtering all the peaks of the noise!
But, I believe you can achieved the same and better result with a better decoupling is some areas of circuit, there is no need to change the electrolytic capacitors.
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First, sorry for the confusion. My readings were made using battery only! Next, my L2 is L3 on this new schematic and is same as L2 on TomC's reverse-engineered schematic! It's the coil used by the MC34063A to generate negative voltage. Compared to the new schematic, some components are missing on my board. First, there was only one green 470 µF 16 V electrolytic capacitor right next to the IC. There are (originally unpopulated) foorprints for another electrolytic and ceramic capacitors next to the connector.
Anyway, I found components that to me look like the snubber for the diode (but I didn't use that, since power is coming from the battery, right?). They are marked C4 and R11. C4 shows 2.287 nF, which is pretty close to expected value, from what I can see. R11 gives 21.7 ohm reading on my multimeter, so that too looks OK. The soldering of R11 was bad in my opinion, so resoldered it.
My problem with the capacitors is that I don' have an ESR tester at the moment and my multimeters can't measure large electrolytic capacitors. I'm making a crappy one from schematics of an old Poptronix kit, so maybe that will help and maybe not.
As for the ferrite, I'll post a picture of it when I get a camera. It's about the size posted maybe 20 pages back.
I'm off to get a camera now, so hopefully my next post will have photos of the PSU itself. Thanks for all the ideas!
If you took the readings using the battery only, then the 8.4V, which is the majority of what's in the PSU board, is probably not involved. The only thing left is the -7.6V in the PSU board and all the DC/DC converters in the adapter board. I would concentrate on the filter components for those in this case.
To check electrolytic capacitors you need an ESR meter, in all the years I've been troubleshooting electronics, 99% of all electrolytic troubles were diagnosed with an ESR meter. The capacitance usually checks OK even if the capacitor has a very high ESR. The alternative, which works maybe 50% of the time, is to visually check under the capacitors (if radial) for signs of leakage or corrosion. If you see that you should replace the electrolytic capacitor.
Just for a simple idea of how to build an ESR meter, I attached a schematic of the one I built back in the 70's. Actually I was still using this a couple of years ago when I upgraded to a microprocessor based LC & ESR meter. Unfortunately I don't have specs for the transformer, I think I used what I had on hand and then altered the meter's scale to match it.
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These attached photos have full resolution but with some compression for less Mb...
As I told you, there is same like yours but with other revision PCB-T113-J Rev.6 (through-hole components). These photos are without any mods.
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These new pictures are much closer to what I have. One thing that I immediately noticed it that the ground connections on the top of the board are cut while they are connected on my board! They exist only on the bottom. I'll experiment with isolating top ones and report back what happens.
Here are two pictures of my PSU. I've marked components on the top side whose markings were hard to determine from the photo. All components on the bottom were added by me. If you need close-up of any specific area, please let me know. EC8 is normally soldered and had additional SMD ceramic capacitors, but I removed them for debugging purposes.
Once again, this is PCB-T115-J rev4.
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Sorry for double-posting, but I had to do this!
BAM!!!!!
It's the top ground connection that's making most of the problems!!!! I just placed a piece of paper between the top of the PSU and the mounting holes and I got results in calibrated.png! I think I have some insulating washers in my junkbox, so I'll try them out. They should probably make a better permanent solution to this problem.
The problem of 80 ms pulses still remains to be identified, so I'll focus on it now. To me it looks like ground noise this large is within usual levels, unless I'm mistaken.
Also those huge voltage spikes that were intermittent and above the usual are now gone.
Update: I added the insulating washers under the top screws and it solved that problem. Another interesting issue us that now, when the battery is supposed to be charging, the LED keeps blinking. Perhaps some of the modifications I did upset the charging circuit? Also the remaining battery indicator keeps changing values pretty quickly as well. Just to be safe, I removed the battery until I can investigate this. Without the battery, the green LED is on, as expected.
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Sorry for double-posting, but I had to do this!
BAM!!!!!
It's the top ground connection that's making most of the problems!!!! I just placed a piece of paper between the top of the PSU and the mounting holes and I got results in calibrated.png! I think I have some insulating washers in my junkbox, so I'll try them out. They should probably make a better permanent solution to this problem.
The problem of 80 ms pulses still remains to be identified, so I'll focus on it now. To me it looks like ground noise this large is within usual levels, unless I'm mistaken.
Also those huge voltage spikes that were intermittent and above the usual are now gone.
Update: I added the insulating washers under the top screws and it solved that problem. Another interesting issue us that now, when the battery is supposed to be charging, the LED keeps blinking. Perhaps some of the modifications I did upset the charging circuit? Also the remaining battery indicator keeps changing values pretty quickly as well. Just to be safe, I removed the battery until I can investigate this. Without the battery, the green LED is on, as expected.
AndrejaKo, Just to let you know my thoughts after your last update.
The ground that you have isolated on the PSU board corresponds to the GND-C on the PSU schematic I reverse engineered. That ground is isolated on that PSU version. However, on the newest PSU that Owon is shipping now, they have gone back to grounding it locally to the Z plane, as in your board. In any case, this ground doesn't remain isolated from the Z plate for long any way, because it connects to the adapter board via pins 7 & 8 of the adapter connector. As you know, on the adapter board there are several pads that connect this ground to the Z plane when the board is attached to it with it's screws.
So in view of the above, I think the reason you are getting better results now is because GND-C, before it gets to the adapter board and the rest of the scope, has to go through the ferrite you have on the adapter cable. To me, that indicates that some of the noise is being generated on the PSU board. Since (based on you previous post) you get the noise when operating on battery only, it seems that the best candidate for a noise maker is the -7.6V DC/DC converter circuit.
The problem with the LEDs acting funny when the battery is charging is probably an entirely different problem, possibly related to one of your mods as you said. I think you can probably troubleshoot that with just a multimeter by checking some voltages. In the Theory of Operation I previously posted there is an explanation of how this circuit works on pages 3 and 4. I'm going to attach a copy of it to this post in case you want to take a look at it.
Good luck and keep us posted! :)
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AndrejaKo, I don't understand what top ground you talk about, you said "It's the top ground connection that's making most of the problems"
Anyway, I upload some suggestions mods to your psu board. It is something like yours mods but they based more to changes to new Owon board and some other mod from previous messages.
I have note over the photo the marks that I believe to put some smd capacitors. At the output that the ribbon cable was fixed you can mod like the new Owon one, this is the blue line that I draw.
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Lemon, take a look at the picture you edited. The "top ground" is term I used to refer to the two ground connections on the right side of the photo.
Anyway, about the blinking LED: From what I can see, it's blinking correctly. The PSU seems to be switching on and off.
Did some measurements with a multimeter and here are the results (I used component markings from TomC's reverse engineered PSU schematic):
When the PSU is on, scope is off and battery is disconnected I get 7.5 V on the D9, EC3, R11 joint and I get 8.5 V on the battery jack and LM324 power pin. Green LED is shining.
When the PSU is on, scope is on and battery is disconnected I get 8.4 V on the D9, EC3, R11 joint and I get 8.3 V on the battery jack and LM324 power pin. Green LED is shining.
Rail marked -7.6 V reads -7.55 V on the adapter board power cable and voltage marked 8.4 V(sw) is 7.6 V to 7.7 V
When the PSU is on, scope is off and battery is connected I get 1.5 V on the D9, EC3, R11 joint, jumping up when LED blinks and I get 7.73 V on the battery jack and LM324 power pin. Green and red LED is blinking.
When the PSU is on, scope is on and battery is connected I get 1.5 V on the D9, EC3, R11 joint, jumping up when LED blinks and I get 7.4 V on the battery jack and LM324 power pin. Green and red LED is blinking.
Rail marked -7.6 V reads -7.55 V on the adapter board power cable and voltage marked 8.4 V(sw) is 6.7 V to 6.8 V, jumping up when the LED blinks. I can also hear a tick whenever the LED blinks. I guess this is probably from the movement of the coils.
I believe that when the power is on and the battery is in, the scope is actually running from the battery and not from the mains power. PSU also seems to be resetting all the time for some reason and will not enter current limiting mode to charge the battery. It's behaving as if the output is shorted. I'm currently charging the battery by hand and testing out how the PSU behaves with different charge levels. It's voltage is at 8.17 V now and there are no changes to the way PSU is responding. I'll do some more checking on the first tho op-amps on the LM324. To me it seems as if the problem could be somewhere close to them.
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AndrejaKo, I gave a quick read to your post, and it seems to me the 8.4V is running in hiccup mode. This may be caused by overvoltage protection. I think you mentioned you replaced all the diodes with UF4007, maybe you should try changing D6 back to 1N4007. Without further modification to this circuit, the UF4007 may be providing too much voltage to the R7731A PWM controller.
I didn't have too much time to analyze what you just posted because I have to run some important errands. When I come back I'll look at it in some more detail and give you more feedback if you haven't yet found the problem.
Good luck, and keep us posted! :)
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AndrejaKo, I understand now what was the "top ground"...OK
Just I made a quick read to your post. Very carefully with the Richtek R7731A, because it is dip8 and there isn't nothing everywhere (only smd version).
Before time ago I destroyed one R7731A and cost me like a new psu board! There isn't available in dip8, only to few dealers to China with 5-8$ each and 25$ cost of shipping!
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@TomC
I replaced D6 with 1N4007 and the power supply isn't resetting itself any more when the battery is in. On the other hand, the battery was by then almost charged by hand and I of course forgot to test the PSU with the battery before changing the D6. I'll discharge the battery now and report back what happens. Thanks a lot for the assistance!
@lemon
I'll be careful with it! Thanks for the tip! I'll try to keep my modifications as far away from it as possible.
Update: I discharged battery back to one half and now it seems to be charging correctly.
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@TomC
I replaced D6 with 1N4007 and the power supply isn't resetting itself any more when the battery is in. On the other hand, the battery was by then almost charged by hand and I of course forgot to test the PSU with the battery before changing the D6. I'll discharge the battery now and report back what happens. Thanks a lot for the assistance!
@lemon
I'll be careful with it! Thanks for the tip! I'll try to keep my modifications as far away from it as possible.
Update: I discharged battery back to one half and now it seems to be charging correctly.
That's great news! :-+
Now you can concentrate on the noise. Maybe you can test the GND noise again using Lemon's post as a guideline and post the results. Personally I would like to see Average Mode 16 at 10M added to that to also get an idea of overall scope performance.
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AndrejaKo, I understand now what was the "top ground"...OK
Just I made a quick read to your post. Very carefully with the Richtek R7731A, because it is dip8 and there isn't nothing everywhere (only smd version).
Before time ago I destroyed one R7731A and cost me like a new psu board! There is available in dip8 only to specific dealers to China with 5-8$ each and 25$ cost of shipping!
That's pretty outrageous! While researching the PSU circuits I ran into datasheets for several other IC's almost identical to the R7731A. I'm not sure if they are completely interchangeable without circuit modifications. But switching to a different manufacturer may be an alternative if they stop making the Richtek or the price becomes prohibitive.
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TomC this chip was my nightmare.
I couldn't to find it, I search all the knows sources but nothing, only smd version (sot 23-6) from China (that is including from your version and after).
For these reason I sent a request for sample to Richtek Company. Finally they send me (command from Richtek USA) sot 23-6 version not dip8! |O
I had to make a prototype micro board sot 23-6 to dip8 but I have only explotion... all the time the resistor R9 (0.67-0.68 Ohm), the mosfet Q1 and NTC-10D-11 booom!
I don't know why, I done many times check to paths, the characteristics are identical btw sot and dip version (only the legs differs), it dosen't work! Probably the send me other IC, who knows with funny marks of smd.
Finally, I paid a lot of money to bought dip version direct from China at prices that I said!
AndrejaKo very well! We'll waiting for the noise now!
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TomC this chip was my nightmare.
I couldn't to find it, I search all the knows sources but nothing, only smd version (sot 23-6) from China (that is including from your version and after).
For these reason I sent a request for sample to Richtek Company. Finally they send me (command from Richtek USA) sot 23-6 version!
I had to make a prototype micro board sot 23-6 to dip8 but I have only explotion... all the time the resistor R9 (0.67-0.68 Ohm), the mosfet Q1 and NTC-10D-11 booom!
I don't know why, I done many times check to paths, the characteristics are identical btw sot and dip version (only the legs differs), it dosen't work! Probably the send me other IC, who knows with funny marks of smd.
Finally, I paid a lot of money to bought dip version direct from China at prices that I said!
AndrejaKo very well! We'll waiting for the noise now!
I don't know why that happened, like you said, the function is identical. You would think the adapter board you made should have worked. The only difference I can think of is the power rating, the SOT version is lower, maybe the adapter board didn't provide enough heat dissipation. But you would think it would at least work for a while until the heat was too much. Hope is a mystery you won't have to deal again with.
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You have right, it should have worked for a while, but just switch-on the ac...boom.. like a short-circuit. Maybe take a capture of adaptor board for what marks have it?
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You have right, it should have worked for a while, but just switch-on the ac...boom.. like a short-circuit. Maybe take a capture of adaptor board for what marks have it?
Yeah, if you still have it, I'd like to see a picture of it.
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Sorry, I'm unable to do the recommended mods at correctly at the moment. I'm out of 220 nF and 1.5 nF capacitors (I usually don't use them), so I'll have to get some more tomorrow.
Images made with scope running on AC with no battery.
First attached image are implemented capacitors. Capacitors in red ellipse are ones I managed to place. I'm not sure how t implement ones with a question mark next to them. I'm still looking for a suitable bar to use.
Second image is scope in average mode with 10 meg memory.
Third image is scope in peak-detect as described previously.
Fourth image is scope in scan mode where large peaks can be seen. Looks like the big peaks are back.
I'll report back when have needed components.
Also how well are your scopes handling the experimenting in the mechanical sense? My scope is starting to show some signs of wear. For example, the screwdriver slots on the M type screws of the PSU are getting worn (I'll probably replace them soon) and screws holes for the back cover are getting loose on my scope. I also added two non-populated screws that hold the screen attached to the front cover on the left side, since I'm not using back cover screws at the moment to decrease the wear of the mechanism.
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Sorry, I'm unable to do the recommended mods at correctly at the moment. I'm out of 220 nF and 1.5 nF capacitors (I usually don't use them), so I'll have to get some more tomorrow.
Images made with scope running on AC with no battery.
First attached image are implemented capacitors. Capacitors in red ellipse are ones I managed to place. I'm not sure how t implement ones with a question mark next to them. I'm still looking for a suitable bar to use.
Second image is scope in average mode with 10 meg memory.
Third image is scope in peak-detect as described previously.
Fourth image is scope in scan mode where large peaks can be seen. Looks like the big peaks are back.
I'll report back when have needed components.
Also how well are your scopes handling the experimenting in the mechanical sense? My scope is starting to show some signs of wear. For example, the screwdriver slots on the M type screws of the PSU are getting worn (I'll probably replace them soon) and screws holes for the back cover are getting loose on my scope. I also added two non-populated screws that hold the screen attached to the front cover on the left side, since I'm not using back cover screws at the moment to decrease the wear of the mechanism.
I haven't taken apart my scope that many times, so wear and tear is OK for now. If you have a chance, can you capture the same tests running the scope from the battery and post them. It would be helpful for comparison.
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AndrejaKo, The last capture, with the high amplitude pulses, roughly comes out to be 25Hz bursts about every 140ms. Resembles something like some sort of telephone ringing cadence. Are you by any chance in the vicinity of telephone switching equipment. Just a wild guess! The pattern reminded me of a telecommunications course I used to teach, so I thought I'll ask, just in case.
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You have right, it should have worked for a while, but just switch-on the ac...boom.. like a short-circuit. Maybe take a capture of adaptor board for what marks have it?
Yeah, if you still have it, I'd like to see a picture of it.
The marking is DP=JCM. Look at the attachment captures.
...
I'm not sure how t implement ones with a question mark next to them. I'm still looking for a suitable bar to use.
...
Because the middle foot of mosfet is away fron the gnd, you can put the smd like the schema and joined it by a short cable.
Generally, the values of smd capacitors is from major works of rf-loop and Siri (both of them are member of EEVBlog) adapted to ours versions. I don't know exactly what values of smd caps Owon used to the last version, I supposed that used the rf-loop's suggestion.
AndrejaKo, I estimated that your noise, after a good decoupling work on psu, falls at 100mV level about. The next is adapter Ver3.0 board...
By the way, which is the scan mode? I remember that have 3 modes: Sample, Peak, Average (Acq. Mode)
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There was no telephone switching equipment near when I made the ringing images.
The scan mode has to do with triggering. If you set the s/div value low enough, the scope will stop triggering in the classical way and will switch to scan mode. In it, the waveform will "flow" across the screen from right to left.
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AndrejaKo, thanks for the info. :-+
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[The marking is DP=JCM. Look at the attachment captures.
That should have worked if you had the correct chip. The chip they gave you probably had a permanent positive voltage on the gate pin and turned on Q1 all the time. That's the only explanation I can think of for it to fry all the components you mentioned.
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I don't know exactly what values of smd caps Owon used to the last version, I supposed that used the rf-loop's suggestion.
While I had the scope apart I measured the SMD caps on the new PSU board. Most of them didn't give me a true reading because of the surrounding circuits, but the few I was able to measure were around 220nF. These were of the thicker type. There are also thinner caps I couldn't measure, I suppose those are the 1.5nF ones.
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There was no telephone switching equipment near when I made the ringing images.
Do you get that same ringing image when running from the battery only?
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I took some pictures of modifications from yesterday when running on battery in room with no electronics devices. They are the first two attachments and I was quite happy with the results. Ringing did remain!
I decided to try to implement all modifications from the lemon's picture, but I got some pretty bad results. Image is the third attachment.
Next, I removed the bar and the capacitors going from the bar onto the connector, but I forgot to take a picture. Next, I removed all of today's mods, but I couldn't get near the results I got this morning with yesterday's mods. That's the fourth attachment.
I also noticed some new bursts of noise coming and they're in the fifth attachment. They are completely new and didn't exist until today. I'll carefully compare my picture old PSU mods to see if I did something and forgot about it.
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I took some pictures of modifications from yesterday when running on battery in room with no electronics devices. They are the first two attachments and I was quite happy with the results. Ringing did remain!
I decided to try to implement all modifications from the lemon's picture, but I got some pretty bad results. Image is the third attachment.
Next, I removed the bar and the capacitors going from the bar onto the connector, but I forgot to take a picture. Next, I removed all of today's mods, but I couldn't get near the results I got this morning with yesterday's mods. That's the fourth attachment.
I also noticed some new bursts of noise coming and they're in the fifth attachment. They are completely new and didn't exist until today. I'll carefully compare my picture old PSU mods to see if I did something and forgot about it.
The first two pictures look quite good! If you can get back to that, that level of noise is acceptable and you should be able to work with low level signals while using the long ground lead.
What I find puzzling is the low frequency high amplitude spikes. Since you get them running from AC or battery, I don't think the 8.4V supply can possibly be involved. Where are they coming from? That's a hard question to answer! Do you have any other scopes available to help troubleshoot?
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Something is going wrong, sure!
The result on third capture is bad!
I searched this thread to find my older posts about same mods. All there are to page 88 and then. From this page with the same mods (not to adapter board, only to psu board without any ferrites) my results was:
(https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/?action=dlattach;attach=52186;image)
Before the adding smd decoupling capacitors, I have changed all the electrolytics capacitors. Look at the following image (right is what I had before, left what I take with the new caps)
(https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/?action=dlattach;attach=52105;image)
I don't believe that the results with the smd decoupling capacitors are caused of electrolytic capacitors. All the rf-loop's result are without any electrolytic capacitors changed.
Unfortunately, you didn't take a capture of all these mods that you done. Perhaps, someting goes wrong!
Did you believe that you helping if I take a photo capture from my board with the mods?
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I don't know exactly what values of smd caps Owon used to the last version, I supposed that used the rf-loop's suggestion.
While I had the scope apart I measured the SMD caps on the new PSU board. Most of them didn't give me a true reading because of the surrounding circuits, but the few I was able to measure were around 220nF. These were of the thicker type. There are also thinner caps I couldn't measure, I suppose those are the 1.5nF ones.
TomC, can you to mark with the arrows on PSU Print Side Circuits Photo what smd are 220 and 1.5?
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I don't know exactly what values of smd caps Owon used to the last version, I supposed that used the rf-loop's suggestion.
While I had the scope apart I measured the SMD caps on the new PSU board. Most of them didn't give me a true reading because of the surrounding circuits, but the few I was able to measure were around 220nF. These were of the thicker type. There are also thinner caps I couldn't measure, I suppose those are the 1.5nF ones.
TomC, can you to mark with the arrows on PSU Print Side Circuits Photo what smd are 220 and 1.5?
Here they are!
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You are really fast like Bolton! Many thanks, I am going to examined vs what we proposed.
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@lemon
If it's not a problem for you, please post image of your PSU with mods. Maybe it will help. I suspect (maybe it would be better to say hope) that the source of this noise is some minor thing that I'm overlooking.
@TomC
The spikes are coming from the power supply itself. I've just connected my computer's microphone input to the PSU, disconnected the adapter cable and turned it on to run from the battery. The noise was there even with the rest of the scope powered down. I don't have another scope (this is my first one), but there is one guy I know with TDS210 who owes me a favor. I'll try to arrange the use of his scope, but that may take a while.
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No problem, tomorrow you will have it.
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Ok, great! I'm too tired to do anything today anyway.
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@TomC
The spikes are coming from the power supply itself. I've just connected my computer's microphone input to the PSU, disconnected the adapter cable and turned it on to run from the battery. The noise was there even with the rest of the scope powered down. I don't have another scope (this is my first one), but there is one guy I know with TDS210 who owes me a favor. I'll try to arrange the use of his scope, but that may take a while.
What happens if the Pwr Sw (J2 ) is not pushed in. I'm asking because with the adapter cable disconnected, the only difference between pushed in or released (on or off), is that in the first case the -7.6V DC/DC converter is energized, and in the second case is not.
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If I can interrupt here for a second...then I'm eat a whole bag of "step out of the way and let the pro's go at it"...
I've been following this thread for awhile, trying to decide on a decent digital 'scope that's a notch or seven better than the old 1052 at not much more cost.
All this talk about ground noise and such, does it have any effect on probing logic level signals (e.g. above a volt or so), triggering on them, and the like?
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@Skimask
Even with all of this noise problems I'm having, I had no problems working with logic level signals at all. This scope won't catch very fast glitches, but if you need to take a look at general purpose I2C, SPI,RS-232,RS485, low or full speed USB and other slow protocols, then it's OK. Of course, it doesn't have protocol decoding, so you'll have to work out by hand what's going on and there's no memory segmentation either.
UPDATE:I made a bar again and this time used 1 µF capacitors between all lines and the bar. Now I have results which are relatively close to the good ones I posted few pages back, but only when the probe is in the fixed position as shown few pages back. If I move it away, then I get the new spikes back, but they aren't as bad as before. This was made when running on battery. I'm a bit concerned how the AC trigger signal is going to work with such a big capacitor on it, so I'll probably go back and change that one capacitor to something lower.
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AndrejaKo: These results are not bad!
But "1 uF capacitors Between all lines and the bar" What do you mean? Bar?
Now to prevent that the probe position affect to the measure -> shielded all the oscilloscope.
http://www.opticalfilters.co.uk/emiclare-ito-film.html (http://www.opticalfilters.co.uk/emiclare-ito-film.html)
http://www.adafruit.com/products/1309#Description (http://www.adafruit.com/products/1309#Description)
http://uk.farnell.com/kontakt-chemie/emi-35-200ml/coating-conductive-emi-35-200ml/dp/2142398 (http://uk.farnell.com/kontakt-chemie/emi-35-200ml/coating-conductive-emi-35-200ml/dp/2142398)
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By "bar" I mean the thing referenced by lemon in his list of recommendations few pages back. Basically, new PSUs have a ground track running near the board edge close to the power connector. There are capacitors running from that trace to the power connector. You can see that in TomC's post with a photo of new board. Lemon recommended that I make a bar (would that be the right term to use here?) and that I connect it to the ground lines at both sides of the power connector and then place capacitors from the connector to the bar. I made the "bar" from a piece of 1.5 mm2 solid copper wire and then connected capacitors to it. I hope this clears things up a little bit.
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Here I am and upload my psu with mods.
If you would like some more explanation, don't hesitate to ask me.
Carrington, the Farnell denied to send me the EMI Shield Spray (it is courier rule for airport transfers).
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AndrejaKo: I understand, thanks for the clarification.
lemon: Try Amazon or eBay.
http://www.amazon.es/KONTAKT-CHEMIE-EMV-Abschirmlack-200/dp/B00154KONS (http://www.amazon.es/KONTAKT-CHEMIE-EMV-Abschirmlack-200/dp/B00154KONS)
http://www.ebay.es/itm/ws/eBayISAPI.dll?ViewItem&item=261076709207 (http://www.ebay.es/itm/ws/eBayISAPI.dll?ViewItem&item=261076709207)
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@Skimask
Even with all of this noise problems I'm having, I had no problems working with logic level signals at all. This scope won't catch very fast glitches, but if you need to take a look at general purpose I2C, SPI,RS-232,RS485, low or full speed USB and other slow protocols, then it's OK. Of course, it doesn't have protocol decoding, so you'll have to work out by hand what's going on and there's no memory segmentation either.
UPDATE:I made a bar again and this time used 1 µF capacitors between all lines and the bar. Now I have results which are relatively close to the good ones I posted few pages back, but only when the probe is in the fixed position as shown few pages back. If I move it away, then I get the new spikes back, but they aren't as bad as before. This was made when running on battery. I'm a bit concerned how the AC trigger signal is going to work with such a big capacitor on it, so I'll probably go back and change that one capacitor to something lower.
If you straighten the problem cable, you catch everything like antenna.
I don't have my scope functionality now, if another member with low level gnd noise test with the straighten the probe cable you'll see that the noise is increased.
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AndrejaKo: I understand, thanks for the clarification.
lemon: Try Amazon or eBay.
http://www.amazon.es/KONTAKT-CHEMIE-EMV-Abschirmlack-200/dp/B00154KONS (http://www.amazon.es/KONTAKT-CHEMIE-EMV-Abschirmlack-200/dp/B00154KONS)
http://www.ebay.es/itm/ws/eBayISAPI.dll?ViewItem&item=261076709207 (http://www.ebay.es/itm/ws/eBayISAPI.dll?ViewItem&item=261076709207)
Carrington, thanks for the links. I had order the other with coating by Nickel, was 400ml vs 200ml of Kontact Chemie. Had you search them more and decided to order the Kontact Chemie?
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Carrington, thanks for the links. I had order the other with coating by Nickel, was 400ml vs 200ml of Kontact Chemie. Had you search them more and decided to order the Kontact Chemie?
Where have you bought the coating nickel spray?
With 400ml on Farnell I only find this:
http://es.farnell.com/kontakt-chemie/graphit-33-400ml/coating-conductive-400ml/dp/836606 (http://es.farnell.com/kontakt-chemie/graphit-33-400ml/coating-conductive-400ml/dp/836606)
I bought the EMI 35 on Amazon.
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From Farnell, look at http://export.farnell.com/jsp/search/productdetail.jsp?SKU=1675347 (http://export.farnell.com/jsp/search/productdetail.jsp?SKU=1675347)
If you can't to open search for order code with 1675347
Also, just came from Farnell this flat ferrite and fits perfect to flat cable of adapter. Look at:
http://export.farnell.com/jsp/search/productdetail.jsp?SKU=3538369 (http://export.farnell.com/jsp/search/productdetail.jsp?SKU=3538369)
If you can't to open search for order code with 3538369
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From Farnell, look at http://export.farnell.com/jsp/search/productdetail.jsp?SKU=1675347 (http://export.farnell.com/jsp/search/productdetail.jsp?SKU=1675347)
Also, just came from Farnell this flat cable and fits perfect to flat cable of adapter. Look at:
http://export.farnell.com/jsp/search/productdetail.jsp?SKU=3538369 (http://export.farnell.com/jsp/search/productdetail.jsp?SKU=3538369)
Ok, I see now.
http://www.farnell.com/datasheets/31877.pdf (http://www.farnell.com/datasheets/31877.pdf)
http://www.farnell.com/datasheets/1674774.pdf (http://www.farnell.com/datasheets/1674774.pdf)
I bought the ferrite on ebay.
http://www.ebay.es/itm/190837205693 (http://www.ebay.es/itm/190837205693)
The SSH-33.5-20 is better, but I do not believe there is much difference.
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Now I have results which are relatively close to the good ones I posted few pages back, but only when the probe is in the fixed position as shown few pages back. If I move it away, then I get the new spikes back, but they aren't as bad as before. This was made when running on battery. I'm a bit concerned how the AC trigger signal is going to work with such a big capacitor on it, so I'll probably go back and change that one capacitor to something lower.
AndrejaKo, try ferrites on the probe cable, one at the top close to the BNC, and one at the bottom, close to the probe itself. See if this helps the spikes when you move the probe cable and when you get it close to the screen.
The ferrites for the flat cable that Lemon and Carrington ordered may also help. Check the links on their posts.
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I'm a bit concerned how the AC trigger signal is going to work with such a big capacitor on it, so I'll probably go back and change that one capacitor to something lower.
There may be a slight phase delay, in most applications that probably wouldn't matter. If you look closely at the new PSU board, you'll notice that C23 is missing. That's the equivalent of the capacitor you are talking about. Evidently Owon didn't think a capacitor there would make very much of a difference as far as EMI is concerned, so they left it out even though it was part of rf-loop's recommended changes. So it probably will be OK whichever way you decide to go.
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AndrejaKo, if you haven't the work of rf-loop, you can see that at:
http://imageshack.us/photo/my-images/571/pic2psu2b.jpg/ (http://imageshack.us/photo/my-images/571/pic2psu2b.jpg/)
The thread for that image is held at: http://owon.forumup.com/viewtopic.php?t=163&start=0&mforum=owon (http://owon.forumup.com/viewtopic.php?t=163&start=0&mforum=owon)
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With ferrites in place on the probe, I get around 100 mV of noise, but now it doesn't matter how the probe is positioned. I still see the spikes, but they are reduced. Also the large spikes remain. In some positions, I can get as low as 50 mV of noise.
Removing the two insulation washers from under the top ground contacts make the noise look a bit "prettier" on the screen. Now I get a 150 mV thick line and the new peaks are almost invisible. The large peaks are still here.
As for the adapter cable ferrite, I already tried with few additional ferrites (both flat and round) and they didn't help much. I also added ferrites on the display cable and the LED cable, but I'm pretty sure that at this point they aren't doing anything useful.
I did try to register for owon.forumup.com once before, but it seems that administrator didn't approve my registration. I tried one more time now. Hopefully, I'll have more luck.
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Removing the two insulation washers from under the top ground contacts make the noise look a bit "prettier" on the screen. Now I get a 150 mV thick line and the new peaks are almost invisible. The large peaks are still here.
Who had added these insulation washers Owon or you? There aren't to mine. At one end of the top ground there is the common point of ac plug earth with the ground of Z-plate.
I also added ferrites on the display cable and the LED cable, but I'm pretty sure that at this point they aren't doing anything useful.
Also to me, there aren't doing any effect to gnd noise.
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I mentioned some posts ago that I added a couple of washers to see if they will help. That was before the addition of ground bar. Before the bar, they were providing great noise reduction (probably due to combination with ferrite).
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With ferrites in place on the probe, I get around 100 mV of noise, but now it doesn't matter how the probe is positioned. I still see the spikes, but they are reduced. Also the large spikes remain. In some positions, I can get as low as 50 mV of noise.
Removing the two insulation washers from under the top ground contacts make the noise look a bit "prettier" on the screen. Now I get a 150 mV thick line and the new peaks are almost invisible. The large peaks are still here.
As for the adapter cable ferrite, I already tried with few additional ferrites (both flat and round) and they didn't help much. I also added ferrites on the display cable and the LED cable, but I'm pretty sure that at this point they aren't doing anything useful.
I did try to register for owon.forumup.com once before, but it seems that administrator didn't approve my registration. I tried one more time now. Hopefully, I'll have more luck.
The part of the noise you no longer see with the probe cable ferrites was due to radiated energy, in my experience, mostly from the screen.
The flat cable ferrite I was talking about before is not for the adapter cable, is for the TFT panel flat cable. My scope came with this ferrite. Carrington's, Lemon's and yours did not, because apparently they started installing this ferrite with adapter version 3.2. I suspect that my scope doesn't show as much noise when I use it without probe ferrites because of the presence of this flat cable ferrite on the TFT panel cable.
The large spikes are still a puzzle, I gather there was no change in amplitude when you added the probe cable ferrites. So it appears that they are not due to radiated energy. If they are present while you run the scope strictly from the battery, it would appear that they are internally generated and passed on as common mode noise conductively. Perhaps when you get another scope we can figure out where they are coming from.
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@Skimask
Even with all of this noise problems I'm having, I had no problems working with logic level signals at all. This scope won't catch very fast glitches, but if you need to take a look at general purpose I2C, SPI,RS-232,RS485, low or full speed USB and other slow protocols, then it's OK. Of course, it doesn't have protocol decoding, so you'll have to work out by hand what's going on and there's no memory segmentation either.
Ya, that's mainly what I'm looking at...what would amount to a single channel logic analyzer.
At the moment, I'm using a couple of Stellaris boards running SUMP, but that 'only' samples at about 100Mhz and doesn't give me any indication on the signals edges, quality, etc.
As good as the Rigol seems to be in this respect, the larger screen/resolution of the Owon seem to push me towards it.
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Skimask, forget the issue with the gnd noise that we talking about. All the scopes from April-May of 2013 and then have low level of gnd noise (?35mV).
If the characteristics and fw of SDS 7102 is appropriate for your job, don't think about Rigol. Except if you can buy the Rigol series 2000, that is much better oscilloscope than SDS7102.
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AndrejaKo probably I have lost episodes about your work.
The spikes - as TomC said - are complex and I am afraid that something going wrong to your PSU Board from many soldering-desoldering.
It isn't logical your noise with 1uF (at the bar) to be 90mV, and with the 220nF to be 290mV!
Please do a check again, have in mind the upload photo of new psu (by TomC), mines photos and rf-loop. The only difference that I saw btw new psu and rf-loop that Owon don't use 1uF smd but only 220/1.5nF
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TomC ,
How many noise have you cut with this ferrite on LCD wire ?
For your opinion if try to do the some with this old Tek 220 I will reduce the noise ?
The new Tek TDS2024 have a ferrite included without modification.
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AndrejaKo probably I have lost episodes about your work.
The spikes - as TomC said - are complex and I am afraid that something going wrong to your PSU Board from many soldering-desoldering.
It isn't logical your noise with 1uF (at the bar) to be 90mV, and with the 220nF to be 290mV!
Please do a check again, have in mind the upload photo of new psu (by TomC), mines photos and rf-loop. The only difference that I saw btw new psu and rf-loop that Owon don't use 1uF smd but only 220/1.5nF
Of course it's not logical that just the capacitor change would make such a difference. It could be that I overheated some component and damaged it, but at the moment I can't think of any component that can be easily damaged in such way. I mean, I've mostly soldered around connectors and electrolytic capacitors. Maybe one of the electrolytics could have been damaged by too much heat? Maybe there are some bad joints? On the other hand, none of my joints look any worse than Owon joints on the PCB. In any case, I'll inspect the whole PSU under a microscope, since I can't think of anything else to do at this time (well except for adding capacitors of various sizes)
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The bad with capacitors is that needs to measure esr for damaged except the capacitance and needs measure out of pcb.
A good looking by microscope will help of course.
If you can find a second oscilloscope, you can search for peak sources.
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The bad with capacitors is that needs to measure esr for damaged except the capacitance and needs measure out of pcb.
A good looking by microscope will help of course.
If you can find a second oscilloscope, you can search for peak sources.
Is it possible also use owon itself by using other channel for only sync (trig) and other channel for total noise. With this sync channel it can pick-up what give sync (trig) related to these peaks. (trig channel can adjust so that it do not disturb display. Then look display. Just after watched peaks do not walk randomly in this noise caos but they lock to middle of screen you know that just this other channel have this signal and nothing other for trig. With this method it can regognize every noise peak source what this system separate parts generate.
Take CH1 to "noise channel" connect noise to this channel (example connect it to probe comp out GND) as before and adjust it good visibility (speed and level) but trigger source channel 2. (this time still "auto" trig)
Now there walk around of screen many kind of noise peaks (adjust speed so that density horizontally is so that can see something (random signals but like caos)
Then, connect other probe to CH2 and set also trigger source to CH2 and trigger mode Normal (not auto) and then, do not connect this probe but just move it just near example main power flyback.
After it trig adjust speed and level so that you can see signal... this signal what give trig is now stopped middle of screen and other noises walk there randomly in time axis. With this method you can look around and after short exercise so that you can use this method reliable... you can regognize what circuit is source for what part of noise chaos. After find how to use it you can also adjust CH display so that it does not interfere with the visibility of the channel 1.
Note: Use 10M memory for maximize samplerate! Noise signals may include frequency components even up to over 200MHz and aliasing may give extremely wrong information if not careful.
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TomC ,
How many noise have you cut with this ferrite on LCD wire ?
For your opinion if try to do the some with this old Tek 220 I will reduce the noise ?
The new Tek TDS2024 have a ferrite included without modification.
Lucas, in general, whether ferrites will help or not depends on the specific situation. If there is common mode noise present in the wires where you use the ferrite it will, if not you probably will not notice any difference. Without knowing whether noise is present or not you can't predict what the outcome will be, you can always try and see what happens!
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Of course it's not logical that just the capacitor change would make such a difference. It could be that I overheated some component and damaged it, but at the moment I can't think of any component that can be easily damaged in such way. I mean, I've mostly soldered around connectors and electrolytic capacitors. Maybe one of the electrolytics could have been damaged by too much heat? Maybe there are some bad joints? On the other hand, none of my joints look any worse than Owon joints on the PCB. In any case, I'll inspect the whole PSU under a microscope, since I can't think of anything else to do at this time (well except for adding capacitors of various sizes)
While you are waiting for another scope, why not try rf-loop's suggestion. It may be a little difficult to implement it at slow M settings (scan Mode), but for example, you can try to trigger on one of these high amplitude spikes (normal trigger) and use a faster M setting.
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My poor old Metrix OX 863 (150Mhz analogue with cursors) bit the dust last week, which is how I found this site and why I am here :)
I decided to look at these new modern fan-dangled scopes, my main uses are the repair of HF Radios, vintage computers (1970's - early 80's) and some automotive engine management signal modification.
I do have a budget of around £500 but I really can not see any point in spending more on a scope than buying one of these kiddies at £250; maybe someone has a better option and if so I would love to consider it :)
So just to double check is this the one I want:
http://www.ebay.co.uk/itm/380611013273 (http://www.ebay.co.uk/itm/380611013273)
Cheers all
Clint
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My poor old Metrix OX 863 (150Mhz analogue with cursors) bit the dust last week, which is how I found this site and why I am here :)
I decided to look at these new modern fan-dangled scopes, my main uses are the repair of HF Radios, vintage computers (1970's - early 80's) and some automotive engine management signal modification.
I do have a budget of around £500 but I really can not see any point in spending more on a scope than buying one of these kiddies at £250; maybe someone has a better option and if so I would love to consider it :)
So just to double check is this the one I want:
http://www.ebay.co.uk/itm/380611013273 (http://www.ebay.co.uk/itm/380611013273)
Cheers all
Clint
Yes, this is the scope featured in this thread. If you decide to buy it verify that the serial number is 1324xxx or higher, that means it was built on the 24th week of 2013 which translates to around June. During that time frame, according to the information we have, Owon began shipping scopes with new PSU and adapter boards that considerably reduced the GND noise issue.
Keep in mind that the SDS7102 is a 100MHz DSO, however, although not advertised by the manufacturer, the usable bandwidth extends slightly beyond 150MHz. If you research the subject a little bit you'll find that DSO's are not quite the same as your analogue CRO. They have many features that enhance their usability, but there are certain things, for example catching glitches, that a CRO or DPO are better suited for. That said, I own several CROs as well as the SDS7102, and 99% of the time I choose my DSO for the job at hand.
Good luck, and don't hesitate to ask if you need more information! :)
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Thanks Tom, most helpful; they do state in the ebay advert that's its the latest June 2013 low noise model but have just asked the serial number question :)
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I must have made a bad joint somewhere. I inspected whole board under the microscope and found a couple of joints that didn't really look so good, so I redid them. I also cleaned everything with alcohol and I now got results which are as good as my previously good results, except for the huge peaks. Smaller peaks are now gone. I'd attach an image of that, but I can't find it at the moment.
I got in touch with the other scope owner I know and it looks like that it will take a couple of weeks for us to find an empty time slot for inspection, since we both have exams starting real soon. My idea is to completely remove the PSU from the scope, fire it up from the battery and then poke around until I hopefully find something.
Rf-loop's idea is an improvement to what I was doing when probing and now I can reliably capture the problematic noise, but my problem now is that I can't pinpoint its location. It seems as if the whole scope is radiating the noise. I switched to my 150 MHz probes for this and I can pick up noise whenever I bring a probe within 1 cm of the Z-plate or the PSU and the whole plate seems to be radiating it with pretty even amplitude. I can see it very nicely when the probe is right next to the coil on the MC34063A, but I don't know how to decide if the noise is coming from there or if it just happens to be on that trace, just like it's everywhere else too.
The large peaks seem to be somewhat repetitive. I'm attaching an animation of how they look over a couple of "cycles". I made the shots using scope's waveform record feature. It seems quite complicated to me to export the whole recording and the manual plus scope's help don't seem to give me a good explanation. In the end, I played it back frame by frame and exported image of each frame. Pause between each frame is 100 ms (plus the time it takes the scope to trigger?).
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Rf-loop's idea is an improvement to what I was doing when probing and now I can reliably capture the problematic noise, but my problem now is that I can't pinpoint its location. It seems as if the whole scope is radiating the noise. I switched to my 150 MHz probes for this and I can pick up noise whenever I bring a probe within 1 cm of the Z-plate or the PSU and the whole plate seems to be radiating it with pretty even amplitude. I can see it very nicely when the probe is right next to the coil on the MC34063A, but I don't know how to decide if the noise is coming from there or if it just happens to be on that trace, just like it's everywhere else too.
I hope I'm not rehashing the same thing you are doing, but just in case, here is an example:
Set the trigger source to CH1 and the mode to normal. Attach the CH1 probe and the long ground lead to the ground lug. Set the trigger level high enough so that the scope triggers intermittently. At this point you should only be triggering on the highest of the high peaks. You can set the timebase to a faster rate so you can examine the peak in more detail. CH2 is now available to see events in different parts of the scope that coincide with the peak that you see on CH1.
I attached a capture where I'm doing this, notice the trigger level. This is just an example so I have CH2 connected to ground also. I don't have the scope open to probe around, otherwise I would have captured something more realistic.
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I must have made a bad joint somewhere. I inspected whole board under the microscope and found a couple of joints that didn't really look so good, so I redid them. I also cleaned everything with alcohol and I now got results which are as good as my previously good results, except for the huge peaks. Smaller peaks are now gone. I'd attach an image of that, but I can't find it at the moment.
I got in touch with the other scope owner I know and it looks like that it will take a couple of weeks for us to find an empty time slot for inspection, since we both have exams starting real soon. My idea is to completely remove the PSU from the scope, fire it up from the battery and then poke around until I hopefully find something.
Rf-loop's idea is an improvement to what I was doing when probing and now I can reliably capture the problematic noise, but my problem now is that I can't pinpoint its location. It seems as if the whole scope is radiating the noise. I switched to my 150 MHz probes for this and I can pick up noise whenever I bring a probe within 1 cm of the Z-plate or the PSU and the whole plate seems to be radiating it with pretty even amplitude. I can see it very nicely when the probe is right next to the coil on the MC34063A, but I don't know how to decide if the noise is coming from there or if it just happens to be on that trace, just like it's everywhere else too.
The large peaks seem to be somewhat repetitive. I'm attaching an animation of how they look over a couple of "cycles". I made the shots using scope's waveform record feature. It seems quite complicated to me to export the whole recording and the manual plus scope's help don't seem to give me a good explanation. In the end, I played it back frame by frame and exported image of each frame. Pause between each frame is 100 ms (plus the time it takes the scope to trigger?).
Also note TomC's good advice. (and of course (as TomC advised) you can swap channels, which one you take trig and which one you look signal. (some times and/or for different peoples and light situations this yellow color may be better for use as "main" channel)
If source for this high peak is inside scope (and I believe it is) you can find source.
But you need perhaps change method/thinking how to probe/diagnose it.
In your animation there is aquire mode "peak" and speed 10ms/div. Signal is coming CH1 and you have level triggered to this peak using same channel CH1. Becouse this, only information what we have is that there is these level peaks what are about double level related to other noises level.
For detect where from it come and detect what is "inside" this one peak it may need some amount more.
How to localize this noise peak source.
You tell that you can pick up it "everywhere".
Connect CH1 probe using 10:1 setting in probe and scope to example probe comp out GND or other place of GND what exactly same place you can use also later (for keep same settings and get comparable information) Set vertical so that it is center of screen.
Do not now care about trigger anything. Only watch this TFT and there running noise (here you can use also slow speed and peak mode. Adjust level so that you can see these highest peaks highest level are peaking around 4th div up from vertical centerline (baseline).
And in all cases keep this CH1 probe connection and level settings.
Do not change anything in CH1. Remember where is highest peaks peak level around (not exatly of course).
Acquire mode normal (not Peak!)
Change horizontal speed first to example 100us or example 10us.
Memory so that with 2 channel mode it use 500MSa/s per channel what ever speed you use what need related to this problem. (this is important)
Connect other probe to CH2. (use also here now first 10:1 setting)
Change trigger source to channel CH1.
Trigger mode Normal.
Adjust CH2 level so that its base trace is around -2 - -3div down from center. ( is more easy if keep CH2 visible but so that it do not overlap CH1 on the upper half of screen.)
In this phase scope do not trig or it trigs depending what is on CH2 and how is trigger level set.
(and of course use trigger coupling DC and rising edge in this case now)
Now take CH2 probe hook out (hook is too big antenna) and take GND wire totally out from probe (no need at all now and it is danger for make short circuits inside scope probing and it is also antenna, so take away.)
Now there is GND area and center pin visible. Take small piece of some small isolating tube and put it over center pin and GND area. See picture attached, there is CH2 probe (but in this case I use Hewlett-Packard 300MHz probe)
Now it is perhaps enough unsensitive so that it give enough level only very near of source what we want find. Of course also need adjust CH2 vertical V/div so that CH2 is not too sensitive!
If you have not yet adjusted CH2 trigger level it is baseline of CH2. And you can see signal on the TFT if there is enough signal for produce trig. (becouse you are not in Auto trig mode, it do not generate automatic (unsync) trig in case there is not available real trig. (and THIS may lead many cases totally wrong findings... Auto trig is nice but it is also danger in some situations)
Now pick-up some signal to CH2, example move this "capasitive near field" probe head now near to main power flyback secondary (example near secondary diodes heatsink)
Adjust now CH2 level so that you get "something" around 2-3 div high yeallow signal on screen.
Now, start adjusting trigger level (CH2 is now trig source) until it trig these around highest signals in CH2. Now after you get steady trigger in CH2 keep it and look CH1 red trace. Some noise component is now there stopped and all other sources noise components are moving randomly.
What kind of signal there in CH1 is now sychronized. If it is not what we are finding, move probe CH2 position and pick up other suspected source. When you find what you have try find you see this level of signal locked what you remember when you first adjust CH1 level.
Now your CH2 probe is near this source. If you change some other position you see there is some other noise peak in CH1 locked to trigger time position. (look only this horizontal area where is CH2 trigger position horizontally)
Now you can look CH1 signal (and CH2 is just only for trig)
With this method you can go inside this very fat "noise" trace and if this trace noise level is example 6 div peak to peak you can easy find under 0.5div high sigle noise peak source there well under total noise noise level as long as CH2 lock this signal to trig position. (becouse this signal stay locked and others trawel over screen wildly your eyes do not need look these other noises, just this locked signal there is important and this is coming where is your CH2 probe. Now you can zoom in this peak, chnage CH1 better level etc. Now if you make changes in this noise source circuit you can also exactly see what change happend just in this noise signal level and other things (example its frequancy/risetime figure)
Keep care that CH2 is not too sensitive so that it pick up too much signals. If you put CH2 probe (insulated) to only Z-Plate and it give trig, your adjustment is far too sensitive in CH2. It need give trig only very close this noise peak real source.
After you get this highest noise peak (or what ever it is becouse from 10ms/div and peak mode showed peak we do not know "anything") locked in CH1 using this CH2 trigger pick-up method then adjust horizontal speed for better visibility. Your CH2 probe is now very very near this peak source circuit.
In image, this is example how to arrange this CH2 probe. And note agen, NO GND, only capasitive pick up with this around 5mm long probe own center pin what is there inside this red isolation tube. (black isolation is over probe GND area (this probe is more thin than Owon probe).
There can also use other kind of probe. (magnetic loop probe)
But this small capasitive pick-up is well enough for this case here now.
Probe hook out. From center pin to GND area around 1 - 2 turn round coil (just without any extra leads), diameter around 6-8mm and this all inside isulation. This kind of probe is very unsensitive but if there is RF near this coil it pick up it. It need quite strong field. But, this is what many times need inside some equipment trouble shooting. But this do not need now here.
In this image is this "capasitive" pick-up probe for this Owon case now.
CH2 pic-up sensitivity need reduce so much that trig can do only from very very close signal source. Then it do not trig from "all" noises but just wanted source. What signal is now locked in CH1 trace is this noise what is generated in this circuit where CH2 probe get trigger. Yes it need some experiments and exercise. After can use this method, you really can go inside this total noise and find what fraction of noise is coming from this circuit where your CH2 probe is and what is this source noise "signature".
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I mostly posted the animation to show the general pattern of the peaks. They are always in groups of 2 and 3, with the 3rd one disappearing from time to time.
Anyway, thanks to rf-loop for providing more specific probing instructions!
What is confusing me here is the fact that on the L2 coil near the MC34063A I have the noise riding on top of a square wave. This give the highest amplitude to the noise, so I could conclude that this is the noise source. On the other hand, if I probe near the MC34063A, the amplitude of the noise of lower, but the shape of the wave is same. The amplitude difference is just the height of the square wave I'm picking up. I placed a body of an aluminium electrolytic capacitor over the L2 coil and it seems to filter out the square wave, so now I'm only getting the noise, which has same amplitude as the noise near the MC.
Another place where I can get good noise is between the large carbon resistor marked R33 and UTC TL431K. The noise itself seems to have the greatest amplitude there if I don't count the square wave.
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I mostly posted the animation to show the general pattern of the peaks. They are always in groups of 2 and 3, with the 3rd one disappearing from time to time.
Anyway, thanks to rf-loop for providing more specific probing instructions!
What is confusing me here is the fact that on the L2 coil near the MC34063A I have the noise riding on top of a square wave. This give the highest amplitude to the noise, so I could conclude that this is the noise source. On the other hand, if I probe near the MC34063A, the amplitude of the noise of lower, but the shape of the wave is same. The amplitude difference is just the height of the square wave I'm picking up. I placed a body of an aluminium electrolytic capacitor over the L2 coil and it seems to filter out the square wave, so now I'm only getting the noise, which has same amplitude as the noise near the MC.
Another place where I can get good noise is between the large carbon resistor marked R33 and UTC TL431K. The noise itself seems to have the greatest amplitude there if I don't count the square wave.
As told long long time ago -7.6V SMPS is one of most bad noise source.
(if this is now clear that these most high peaks come from it. It can proof with this separate trig method)
Specially some old PSU version design is very extremely poor in this area.
If look there this "magpie's nest" GND area it is really terrible. (just this point least it can specially think, "perhaps designer have been drunk".)
Is your version this where also power switch metal case is connected to very noisy area of this "transmitter" tank "coil" (this stupid GND loop what go around this -7.6V SMPS and where componets are distributed to GND just as design some DC circuits. I hope he take next time more easy project and design example simple pocket torch with battery, switch and bulb).
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Yes rf-loop he has this version of PSU (PCB-T115-J Ver3).
For this reason among the changes that I suggested to him, was to cut this connection.
I think it is clearly now from where come these peaks. But it is strange why there aren't these before!
I think that this area fried a lot of by soldering-desoldering.
Perhaps the coil and IC must changed. Of course the coil is easy to checked before.
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@lemon
Just to note, I've been mentioning these peaks from the beginning! They are NOT new. I had some smaller peaks that disappeared after latest intervention on the PSU and I've been referring to these old peaks as "large peaks" in several posts. You can see them in my previous pictures for example:
https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/?action=dlattach;attach=57473;image (https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/?action=dlattach;attach=57473;image)
https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/?action=dlattach;attach=57401;image (https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/?action=dlattach;attach=57401;image)
https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/?action=dlattach;attach=57405;image (https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/?action=dlattach;attach=57405;image) (both peaks and the noise on the coil visible)
https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/?action=dlattach;attach=57407;image (https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/?action=dlattach;attach=57407;image)
It's just that with the usual way of measuring noise, scope doesn't trigger on them.
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One other time I have lost episodes... |O
I think that to this area yours and mine psu are identical, but I haven't these peaks ???
Finally, maybe the change that made to electrolytic capacitors, has played an important role?
https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/?action=dlattach;attach=52105;image (https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/?action=dlattach;attach=52105;image)
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I'll see if I can get some better electrolytic capacitors and attempt replacement if I can easily source them.
Also does anyone know the specifications of the coil next to MC34063A? I think that inductance is already shown in available schematics, so I'm particularly interested in current rating of it.
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I'll see if I can get some better electrolytic capacitors and attempt replacement if I can easily source them.
Also does anyone know the specifications of the coil next to MC34063A? I think that inductance is already shown in available schematics, so I'm particularly interested in current rating of it.
The circuit used by Owon is almost identical to the one in the MC34063A datasheet (see attachment). I don't know the current rating for the coil, but perhaps you can get some idea by measuring the current going through pin 4 of the adapter cable. That would be steady state current, not peak, so you need to increase that to get a safety margin. I would also consider using a different geometry for that inductor, for example, toroid. I think the one used by Owon is the bobbin type which is prone to producing EMI (see attachment Inductor Selection). I also attached the original datasheets.
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I'm particularly interested in current rating of it.
Another clue is the Switch's maximum current rating (see datasheet), which is 1.5A, so the coil's current rating is got to be less than that.
You can also try to scope the negative voltage peaks on the side of R40 connected to the IC. Now take 8.4V or whatever voltage you get on your PSU for this supply and subtract the scoped negative peak value. This should give you the voltage drop across this resistor. Ohms law should tell you what the current is during the negative peak value. Most of that current is going through L2.
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Looks like no one has 88 µH inductors... I've checked Farnell Export, Digikey, Mouser and Arrow. Of them, I only managed to find one which has same inductance on mouser, but turned out to be a common mode choke.
Anyway, I'll have to wait until I have a second scope available before I start playing with the inductor. It would be really nice to put a toroidal inductor there and get rid of its field, but if I take that route, I'll most likely have to pick a different but close value and make some prototype circuits with MC34063A to see how it works.
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Looks like no one has 88 µH inductors... I've checked Farnell Export, Digikey, Mouser and Arrow. Of them, I only managed to find one which has same inductance on mouser, but turned out to be a common mode choke.
Anyway, I'll have to wait until I have a second scope available before I start playing with the inductor. It would be really nice to put a toroidal inductor there and get rid of its field, but if I take that route, I'll most likely have to pick a different but close value and make some prototype circuits with MC34063A to see how it works.
I see what you mean about the availability of 88µH inductors. It seems that the standard value is 82µH. I wonder if the 88µH value is an ideal value used in the datasheet, I noticed that in many cases the available components have a tolerance of around ±20%, so it appears that the design has to tolerate a fairly wide range of potential inductance values. In any case, I think that a slightly lower inductance may have a little influence on the converter's maximum current output, so it may work at a slightly different duty cycle, but still give you the same output voltage. The output voltage is really set by the value of R33 and R35. I doubt that it will cause a catastrophic failure and fry the MC34063A, of course, you never know for sure until you try.
By the way, I saw a couple of datasheets for inductors of similar value and similar physical size, the current rating was 1A for an 82µH inductor slightly smaller than L2, and 1.9A for one slightly larger. I attached the datasheets where I saw that.
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AndrejaKo: Why not try this, wrap the 88 µH inductors with aluminum/cooper foil and connects this to GND. But do it for a short time! Just the time needed to see the effect.
Caution, it will get hot!
If you think that noise is coming from the negative voltage, why not use a battery, directly to the 7905.
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If not seen this before:
available from Owon hk download
and also here if Owon.hk sides download have problem.
Owon SDS series SCPI manual (https://app.box.com/s/qxio55nffg83ks9lsfqi)
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If not seen this before:
available from Owon hk download
and also here if Owon.hk sides download have problem.
Owon SDS series SCPI manual (https://app.box.com/s/qxio55nffg83ks9lsfqi)
Thanks for this information! :-+
I noticed the new "SCPI Command Line" button on the Remote Control Panel of the 2.0.8.17 Oscilloscope software. However, when I try to use it emits an error message "SCPI is not support for the machine". I wonder if this is something they are still working on, or if it only works with the latest release scopes. Do you happen to know?
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There is also the Labview opearation cases for SDS series in Drivers Download Menu (Owon site). I haven't used the Labview before, but from what I now the Labview accepte the SCPI commands.
TomC, have you enable the "Continue Data Download" from the "Communication" Menu?
The pdf of SDS SCPI Protocol says:
The SCPI protocol of this product is based on USB port and LAN communication. Run our
software on PC, click to enter remote control, then click the SCPI command on the remoter
control interface to enable SCPI protocol and communicate through SCPI protocol.
(I couldn't to try because I haven't functional my scope, yet)
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AndrejaKo: Why not try this, wrap the 88 µH inductors with aluminum/cooper foil and connects this to GND. But do it for a short time! Just the time needed to see the effect.
Caution, it will get hot!
If you think that noise is coming from the negative voltage, why not use a battery, directly to the 7905.
I tried shielding the inductor with an aluminium can connected to ground, but it didn't help with the large peaks I'm getting.
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AndrejaKo: Why not try this, wrap the 88 µH inductors with aluminum/cooper foil and connects this to GND. But do it for a short time! Just the time needed to see the effect.
Caution, it will get hot!
If you think that noise is coming from the negative voltage, why not use a battery, directly to the 7905.
I tried shielding the inductor with an aluminium can connected to ground, but it didn't help with the large peaks I'm getting.
I have looked your some pictures but I'm some amount confused.
These highest peaks, looks like they are from -7.6V SMPS circuit.
Q1: What is real time interval between these peaks. (measured so that there is enough samplerate for avoid any possible aliasing and trigger mode of course Normal.)
Q2: What is -7.6V SMPS circuit switch timing.
(no need connect GND wire, just connect probe (10x!) tip to 34063A Pin 2)
Is it bursting or continuous cycling and what is timing (example 2-4 cycles, picture) but then if it is bursting with quite low period also burst period (picture).
(example main flyback freq is around 43kHz)
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Hopefully, I'll be able to post that data later today, I'm a bit out of time at the moment.
What I wanted to say it this:
I disconnected ground connection of the power switch and now my noise using the established testing procedure is 50 mV to 55 mV. Large peaks do remain and from what I can see, they are not all that affected by the disconnection.
One more thing I've noticed is that they depend on the input voltage. I got the battery is not enough warning and the large peaks completely disappeared immediately after that.
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Here is picture from -7.6V SMPS.
This is "normal" in ok working PSU.
Powered by 230VAc
Connect probe to D12 kathode (same as 34063A pin 2)
Probe GND to GND
Probe 10x, scope 10x
Memory 100k
Horizontal speed 5us/div
Voltage 5V/div DC
Persistence 1s
Trig Auto, level 0mV, rising edge
There can see around 60kHz square wave with some overshoots.
Frequency and duty is jittering some amount as see in image. (it is normal)
This is continuous waveform without markable changes over time in level or frequancy/duty if circuit works normally. There is NOT any low frequency components what may relate to long periodic high peaks.
It is good to note that these "peaks" in some slow horizontal speed images. (with long random period time) they may be false.)
It was not "without reason" when I have told that it NEED analyze with synchronize method. Not so that trigger channel is same as noise "image" channel. Why: Becouse there is lot of noise peak sources. They are not synch with each others. Some of them use timing jitter for share noise components to more wide spectrum.
Of course some times there is two (or more) peak what in some random time point occurs exactly same time we see sum of these two peaks, if more quite high peaks randomly happend same time we can see "super peak". There happend lot of this kind of interference as we look this "total noise".
For this reason we need go to inside this spread spectrum noise and take lock to each separate noise source, one after one to look.
After then we know what they are and what is real and what are two or more source produced sum. In other way, we see chaos and we can not trust what we see. (if look this total noise and then try use itself to analyze it. We can see lot of mix products and we can not know what is real and what is just some kind of interference "peaks" and then loose time if find in circuit what produce this high peak. (if this peak is this kind of "chost")
One method for analyze it is just go inside this chaos and try lock every separate true noise source (we know these typical sources in this construction) and this locking to separate signals can do with this 2 probe method very very easy and after this we know what are these original real noise "peaks" and stop caring possible random peaks what are perhaps only "chosts" (sum of peaks when they randomly meet each others and produce image of random high peak).
I do not try tell or claim it is just this in this individual case, but it need keep in mind that it is possible - so that do not try find unreal chosts.
Perhaps there is these high peaks what have long and random period time but - keep in mind also this theory what also is possible.
(last spring I use my time more than two hundred lab hours with this case. I have been totally in "forest" before I regognize that nearly only way analyze it is really separate these noises and stop looking this total noise figure - and how to do it. Very very simple. Use two channel, other for lock and other for look signal.)
And more. This noise channel (not synch channel). There travel now high amount of random noises, but some part there is locked to trig point. Now it may be difficult or some small peak cases nearly impossible look this becouse eye need care only this locked part of noisy trace.
After locked (stable trig) this (trig) channel can turn even off if like. (example, if CH 2 is used for trig, after have adjusted trigger as need, CH2 can turn off if do not want momentarily look this channel blinking there. It still can use for trig if it is OFF))
If it is difficult to look locked signal middle of screen when there run randomly lot of high and fast signal over it.
These others are random, only this one what we want look now is not random related to trig time position.
Oh... why we have average mode. It can help in some cases lot of. It can use for filter out these others and now really can see what part is related to source where we get trig.
In this method, trig channel sensitivity need keep so low and probe need go so close to source what we inspect that it do not pick-up any other signals what may disturb reliable trig and give false results.
Here normal D12 kathode (ref GND)
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There is also the Labview opearation cases for SDS series in Drivers Download Menu (Owon site). I haven't used the Labview before, but from what I now the Labview accepte the SCPI commands.
TomC, have you enable the "Continue Data Download" from the "Communication" Menu?
The pdf of SDS SCPI Protocol says:
The SCPI protocol of this product is based on USB port and LAN communication. Run our
software on PC, click to enter remote control, then click the SCPI command on the remoter
control interface to enable SCPI protocol and communicate through SCPI protocol.
(I couldn't to try because I haven't functional my scope, yet)
Yes, that's the only way the control panel can be initiated anyway. But the PDF on SCPI is pretty new, so I hope maybe the trouble is that the scope's firmware release or the Oscilloscope software release needs to catch up with it.
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One more thing I've noticed is that they depend on the input voltage. I got the battery is not enough warning and the large peaks completely disappeared immediately after that.
That's an interesting observation, which may be further evidence that something goes wrong with the -7.6V converter when the input voltage increases. Like rf-loop suggests, it would be a good idea to scope the duty cycle. It may be very low with normal input voltage (8.4V), causing large sporadic current spikes as the feedback loop tries to correct its output voltage.
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It may be very low with normal input voltage (8.4V), causing large sporadic current spikes as the feedback loop tries to correct its output voltage.
Did you read this my last message with image. (there is now my bad english also so that I can not very clearly tell what I mean. It need also keep in mind possibility that these special high random peaks are not real. Becouse this is possible in theory and also seen in practice it need take one possibility also in this case as long as know what it really is.
If look total noise trace where is sum of noises what travel between different GND points and partially changed differential using probe as used when gonnected to GND. What we see. We see sum of separate sources generated signals what we see as "noise".
Now, if think situation we have only one source there, example generating fast "peak". Lets simplify more. If there is example 10ns constant level peaks say example 10us period and 100mV high. Ok, we see these pulses. We can now use low horizontal speeds and get just nice fat trace even if we turn peak mode on. Just nice band without any peaks what are peaking over this noise band.
But what happend if now add other pulses (peaks) say example other 10ns wide 100mV peaks and timing so that they arrive allways example 50ns different time (syncronized so that always this timing - syncronized signals). We see now double amount of nice pulses dependent of horizontal speed. Now we see two pulses. Then we change horizontal speed to very slow and perhaps also turn peak mode on. Agen we see just nice fat band and level is same as before and no any special peaks.
What happend if we now connect off these signals syncronization and they are nearly as before but some amount different freq. Mostly they are different position and we still see this nice fat band without separate peaks. But...wait a moment.. oops, now I just see one or two short 200mV peaks. If frequencies are very very close and they only overlapp each others more or less we see our "noise band" vary between 100mV and 200mV. If they only randomly or hit each others we see just randomly peaks between 100mV and 200mV level.
Of course in practice this is much much more complex how these separate sources "noises" interfere and this is what we see - sum of these "noise" signals.
There IS this kind of short high peaks and these noise peaks are more or less short but there is many sources and more fun there is also variable frequency SMPS circuits and many of these noise "peaaks" are short "oscillations". SDS7102 is some amount too slow scope for analyzing this noise but with right methods it is well enough for regognize sources and analyze if modification give better or worse result (and least this need method where can detect individual source made "noise")
If do not use right methods for analyzing we are perhaps just hunting "ghosts" (or not, but we do not know it)
But more fun come if take this same kind of simplified case but, now, there is agen these two signals but one level is 100mV and other level is 50mV. Then we see 100mV noise band with low horizontal speed... but now if we look more deep we find there 50mV peaks and 100mV peaks and if they run with different frequency... there appear third peak 150mV. But now if we know only what we see there we see 50mV, 100mV and some random 150mV peaks.
Lets start find curcuit what produce just these 150mV peaks becouse we think this is more important becouse this is most high and very odd random peaking just as some "failure". We do not find never circuit what produce this highest and random peaks becouse no one do it.
It is "interference." (in this example).
It disappear just if we stop these 100mV or 50mV peaks (or both) and it go more low if we reduce other of these lower peaks. Also it disappear if frequencies go so that they do not appear same time or they appear so that 99.9% of random peaks fall to scope dead time. Perhaps we need collect 1 day continuous data we can hit this peak if it is rare random. No matter if trigger is set if it is rare and we have auto trig on becouse auto trig generate trig mostly before this rare peak occur in time what is ok for trig to it.
So, before can be sure, there need keep eyes and mind open and avoid hunting "ghosts".
I have looked many times this gif animation and there may be "thousend" reason for it, but one is this possible interference (including also scope itself features with dead and displayed time and trigger)
But, also there may be failure in 7.6V SMPS circuit what produce some odd things in some cases and dependent of this circuit input voltage.
So, this circuit is good to look how it works. Battery lowest is near 6V before battery module shut off its output and highest is around 8.5V and it need work normally in this range.
In normally working SDS with primary PSU voltage around 8.4V this -7.6V have near 50% duty and around 60kHz (center freg).
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Interesting, but ...
Wow, what a mess. :)
Today I received the EMV35, but until a few days I can not do anything.
I am also waiting for other things.
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Did you read this my last message with image. (there is now my bad english also so that I can not very clearly tell what I mean. It need also keep in mind possibility that these special high random peaks are not real. Becouse this is possible in theory and also seen in practice it need take one possibility also in this case as long as know what it really is. ......
Yes, I read it, and I agree there is a chance these are "ghosts" as you put it. I also understood what you meant the first time I read it, so I don't think that your English is hard to understand. :)
For one thing, the R7731 uses a jittering oscillator, so its frequency and all the harmonics are shifting back and forth, therefore increasing the possibility that noise from different sources will occasionally coincide and create spikes equal to their sum. So yes, there is a definite possibility that what you see is not generated by a single source.
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Today I received the EMV35, but until a few days I can not do anything.
I am also waiting for other things.
Great! :-+
I'm curious to see how spraying the cabinet with conductive paint will affect the radiated noise. Were you able to get the transparent EMI film as well?
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If not seen this before:
available from Owon hk download
and also here if Owon.hk sides download have problem.
Owon SDS series SCPI manual (https://app.box.com/s/qxio55nffg83ks9lsfqi)
Owon official answer today.
This feature is not useable now in current version, it is coming in next version what is available soon. (estimated availability next month)
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Yes, this is the scope featured in this thread. If you decide to buy it verify that the serial number is 1324xxx or higher, that means it was built on the 24th week of 2013 which translates to around June. During that time frame, according to the information we have, Owon began shipping scopes with new PSU and adapter boards that considerably reduced the GND noise issue.
Just thought I could add this info about serial numbers of latest versions:
I mailed the supplier on ebay to check I would get a late low noise version and got this reply:
====================
I am sorry but I think this is mistake on EEBLVD, I just checked with manufacturer, our serial # is 1319XXX, it is new version as well ( please e-mail to sales01@owon.com.cn to verify what I am saying if you doubt that ) , 19 not means 19 weeks ( we doubled checked with manufacturer) we warranty you get 2013 June low-noise version ( you can check with manufacturer for the serial # ), for example the serial# SDS71021319652 or later version.
====================
So any I thought I would email OWON and got this reply:
====================
Hello
From the SDS71021319xxx
Best Regards!
2013-08-20
Jason chen
FUJIAN LILLIPUT OPTOELECTRONICS TECHNOLOGY CO.,LTD.
The mansion of optoelectronics hengsan road, Lantian industrial zone ,zhangzhou.fujian.China
TEL?0596?2130430?802
Email: sales@owon.com.cn
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Great! :-+
I'm curious to see how spraying the cabinet with conductive paint will affect the radiated noise. Were you able to get the transparent EMI film as well?
The electric field must be attenuated (~55dB), but the magnetic field is likely to remain intact.
So I do not expect a big improvement,let's see the result.
http://www.adafruit.com/products/1309#Description (http://www.adafruit.com/products/1309#Description)
This sheet is the most affordable I've seen, but is small... I found it on other sites but the same size.
There is another EMI sheet, with a thin metal mesh invisible to the eye, and a high attenuation. The problem is the price ~ 80€.
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Hi guys! Some things took more time than I expected, so I'm a bit late.
First, the duty cycle on the negative regulator is pretty large. I'm currently uploading four pictures. Pictures 1-3 all show in various timebases how a single peak looks like on pin 2 of the regulator. Picture 4 shows how duty cycle looks like.
So the frequency is around 62 kHz and the duty cycle is large, often in the 75% to 85% range. There are also these periods of ringing that are some 80 ms away one from another.
Unfortunately, the peaks are too far away in time for me to capture two in detail on a single scope shot.
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AndrejaKo, if I compare yours 4th capture (duty cycle) with the rf-loop's, seems that your 34063A doesn't work well.
@ Clint = thanks for the info, we had wrong information about this. The major point is that from s/n 1319XXX and then, Owon corrects the gnd noise.
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Well I know that. It's just that I need to determine the reason why. I've had similar results when experimenting due to both coil and circuit arrangement. It's not a problem for me to change the chip, I have several ON Semi 34063As available, but I'd like to be sure that it is in fact the chip that's causing the issue. I also tried replacing the capacitor with an 1000 µF low ESR one (NIC NRSG), but it didn't help on this front, so I'm returning the old one for now.
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AndrejaKo, if I compare yours 4th capture (duty cycle) with the rf-loop's, seems that your 34063A doesn't work well.
@ Clint = thanks for the info, we had wrong information about this. The major point is that from s/n 1319XXX and then, Owon corrects the gnd noise.
First sidenote: I have 1303xxx in stock and just as arrived from factory. And not this bad "GND noise" issue. Just normal.
So..... (but yes, I know why and I know why Owon ask some (still guite short) delay for shipping this lot ;) )
-------------
AndrejaKo:
Something is really wrong in -7.6V circuit. This need repair before any other things. And when repair this, also this circuit need small mods.
(are there noise what disturb 34063A? or some failed component.?)
Specially these rise to middle way and then flat and soon then continue rise to full level.
Then also these short full level pulses... "serious arrhythmia"
Example third image middle (trigger position).
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Well I already tried with capacitor replacement and it didn't help. It's not a too great problem for me to replace the IC, if it's suspect. Coil could be a bigger problem. The closest I can find easily available it 100 µH. From TomC's responses, I came to understand that a lower number should be looked upon as a replacement, but the next lowest I can easily find is 10 µH.
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Well I already tried with capacitor replacement and it didn't help. It's not a too great problem for me to replace the IC, if it's suspect. Coil could be a bigger problem. The closest I can find easily available it 100 µH. From TomC's responses, I came to understand that a lower number should be looked upon as a replacement, but the next lowest I can easily find is 10 µH.
AndrejaKo, I think it is possible that you are having trouble with the current sense ending the cycle prematurely, can you check the value of R40, if it's too high I think it could cause a problem similar to this. R40 is the current sense resistor and when the voltage across it reaches 330mV it ends the cycle.
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Just thought I could add this info about serial numbers of latest versions: ...............
Thanks for sharing this information!
Since both Owon and the dealer confirm that the 1319xxx serial is the breakpoint for the low noise mods, I think it would be OK, as far as the GND noise is concerned, to buy one of these scopes. If you do, it would be very nice if you can post some images of the GND noise test results on your new scope.
As a point of interest, I wonder if the serial number is based on the Chinese calendar as far as the week of the year is concerned. If that was the case, week 19 would correspond to June 16-22 on our calendar. Again, maybe it's just a coincidence.
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If you do, it would be very nice if you can post some images of the GND noise test results on your new scope.
Actually I chickened out and have ordered the Rigol 2072.
As a point of interest, I wonder if the serial number is based on the Chinese calendar as far as the week of the year is concerned. If that was the case, week 19 would correspond to June 16-22 on our calendar. Again, maybe it's just a coincidence.
You know what I was wondering if somehow it could correspond to their tax year or something but I think you are spot on, great thinking !
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Actually I chickened out and have ordered the Rigol 2072.
Very well done. :-+
I bought my SDS without knowing the noise problem, in fact this became known shortly thereafter.
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...
As a point of interest, I wonder if the serial number is based on the Chinese calendar as far as the week of the year is concerned. If that was the case, week 19 would correspond to June 16-22 on our calendar. Again, maybe it's just a coincidence.
From what I saw, the 1st of 2013 was 10 February for China. For example for the serial SDS71021319652 the 19th week is almost at the end of June. But I am afraid that the week in China isn't 7 days period allways...
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From what I saw, the 1st of 2013 was 10 February for China. For example for the serial SDS71021319652 the 19th week is almost at the end of June. But I am afraid that the week in China isn't 7 days period allways...
Lemon, here is a link to the calendar I used to come up with the 19th week being equivalent to June 16-22. I went back to the beginning of the year using the blue arrows and counted the weeks. However, I don't really know if that is the way Owon counts the weeks, it's just conjecture!
http://www.prokerala.com/general/calendar/chinesecalendar.php?month=1&year=4711&lang=en (http://www.prokerala.com/general/calendar/chinesecalendar.php?month=1&year=4711&lang=en)
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As a point of interest, I wonder if the serial number is based on the Chinese calendar as far as the week of the year is concerned. If that was the case, week 19 would correspond to June 16-22 on our calendar. Again, maybe it's just a coincidence.
I doubt that because most Chinese people under 45 don't know much about lunar calendar (Chinese calendar as you quote).
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Just thought I could add this info about serial numbers of latest versions:
I mailed the supplier on ebay to check I would get a late low noise version and got this reply:
====================
I am sorry but I think this is mistake on EEBLVD, I just checked with manufacturer, our serial # is 1319XXX, it is new version as well ( please e-mail to sales01@owon.com.cn to verify what I am saying if you doubt that ) , 19 not means 19 weeks ( we doubled checked with manufacturer) we warranty you get 2013 June low-noise version ( you can check with manufacturer for the serial # ), for example the serial# SDS71021319652 or later version.
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Based on my experience, Owon and/or their ebay agents don't necessarily tell you the whole truth.
My hypothesis regarding serial number 1319XXX is that Owon might salvage the scopes produced in early 2013 (probably replace with the new version PSU board and add capacitor on adapter board).
For those who know my story, I got full refund from my dealer after I returned the scope to Owon. My dealer didn't refund the customs charge and tax, but they sent me an equal value gift.
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First sidenote: I have 1303xxx in stock and just as arrived from factory.
Probably a factory refurbished scope.
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For those who know my story, I got full refund from my dealer after I returned the scope to Owon. My dealer didn't refund the customs charge and tax, but they sent me an equal value gift.
Glad to hear that!
Did you buy a different scope or are you still looking?
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Actually I chickened out and have ordered the Rigol 2072.
Good choice! :-+
From what I've heard it's a pretty solid 70MHz scope with good reviews.
Hope you enjoy your new scope! :)
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For those who know my story, I got full refund from my dealer after I returned the scope to Owon. My dealer didn't refund the customs charge and tax, but they sent me an equal value gift.
Glad to hear that!
Did you buy a different scope or are you still looking?
I am still looking. Probably buy a RIGOL.
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Well I already tried with capacitor replacement and it didn't help. It's not a too great problem for me to replace the IC, if it's suspect. Coil could be a bigger problem. The closest I can find easily available it 100 µH. From TomC's responses, I came to understand that a lower number should be looked upon as a replacement, but the next lowest I can easily find is 10 µH.
AndrejaKo, I think it is possible that you are having trouble with the current sense ending the cycle prematurely, can you check the value of R40, if it's too high I think it could cause a problem similar to this. R40 is the current sense resistor and when the voltage across it reaches 330mV it ends the cycle.
I just checked the value using 4-wire measurement system and I got the expected value. My result is 0.269 ohm. I measured directly from one end of the lead to the other end of the lead. It remains stable over time.
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First sidenote: I have 1303xxx in stock and just as arrived from factory.
Probably a factory refurbished scope.
Arrived from factory stock to my stock March this year!
And these do not have this bad "Noisy GND issue", they are just normal working units.
And here and there have seen test made with these.
clarify: "just as arrived from..." (means factory original condition)
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The next cheapest that I found, but is glass:
http://www.ebay.es/itm/380691935873 (http://www.ebay.es/itm/380691935873)
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I just checked the value using 4-wire measurement system and I got the expected value. My result is 0.269 ohm. I measured directly from one end of the lead to the other end of the lead. It remains stable over time.
That eliminates R40, unless it's intermittent or cold solder joint. To me, this seems to point to the IC's internal circuit, like something wrong with the internal threshold voltages. If you want to get more evidence before replacing the IC, you could try a 1 ohm resistor in parallel with R40, that'll give you a total value of about 0.21 ohms. If this improves the situation, maybe only with battery operation where the input voltage is below 8.4V, it'll point to the current sense threshold inside the IC as being the culprit.
Of course other components are also suspect, for example the coil, but from my experience, coils seldom fail, so something as a short in the winding is less likely, nevertheless possible.
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The half-level points are still there with an ON Semi MC 34063A, but are now a bit different. Now every square starts with at least one pause near the mid level. Sometimes, there are more of those pauses. The difference is that they are usually very, very short, only few tens of nanoseconds in length. There are several types of bad ones, though.
The most common type of square wave is the fast 2 level one. After probing for a while, I'd say that they're more than 90% of captured squares. The is some variation of time it takes to jump from the first voltage level to the second, but it's usually very short.
There are also two more types of square waves I've seen. There's the fast 3 level one. First level dwell time of always very short. There's also a 2 level slow square. It seems to be a bit more common than the 3 level one, but it's still quite rare.
I forgot to show a picture of duty cycle now. It's now mostly around 50%, but goes as low as 40% sometimes and as high as 60% sometimes. At low timebase, the waveform looks healthy.
Also it seems that I forgot to mention the main issue! The large noise peaks are still there. They are not synchronized to any particular point on the MC's cycle. I believe that the noise is just riding on top of the signal MC is creating. The signal on pin 2 of the MC is clean, because I desoldered SMD capacitors I added which connected the MC's power pin to a piece of non soldermasked ground. It seems that somehow the peaks were entering in the MC through them. I added them back for experimental purposes and the peaks on the pin 2 appeared again. Now that I removed them, the peaks on pin 2 are gone too.
The peaks are still the strongest between the TL431 and the "R40" resistor which are almost touching on my PSU. It's also strong near the two 470 µF capacitors marked EC8 and EC5 on my board that are close to 1000 µF electrolytic and L1 coil and in the area near the LM324L. Since this scoping was done on battery power, the area south of the transformer was quiet, as expected.
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The half-level points are still there with an ON Semi MC 34063A, but are now a bit different. Now every square starts with at least one pause near the mid level. Sometimes, there are more of those pauses. The difference is that they are usually very, very short, only few tens of nanoseconds in length. There are several types of bad ones, though.
The most common type of square wave is the fast 2 level one. After probing for a while, I'd say that they're more than 90% of captured squares. The is some variation of time it takes to jump from the first voltage level to the second, but it's usually very short.
There are also two more types of square waves I've seen. There's the fast 3 level one. First level dwell time of always very short. There's also a 2 level slow square. It seems to be a bit more common than the 3 level one, but it's still quite rare.
AndrejaKo, my first impression is that these are much better than what you had before, I don't think these pauses are any longer due to a problem with current sense, they may be more related to the switching characteristic of the output Darlington and stray capacitance. How is the overall cycle, is it anything like what you had before or closer to the image that rf-loop posted? Did you have any improvement on the large noise spikes? Can you post some images of both of these.
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Wow... At the rate that this topic is going, soon will be the winner! 116 and up.
And 200760 Views! I believe that the people enjoy reading about the misfortunes of others... As with a TV serial. ;D
Do not get me wrong, is only a funny note. Until a few pages everyone was very happy with their SDS.
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Hi TomC!
I forgot to show the general duty cycle and to write about the large peaks in the last post, so I updated it. Basically, the peaks are still there and they don't seem to be related to MC's operation. Could the TL431 be producing them somehow? Duty-cycle is close to rf-loop's.
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Hi TomC!
I forgot to show the general duty cycle and to write about the large peaks in the last post, so I updated it. Basically, the peaks are still there and they don't seem to be related to MC's operation. Could the TL431 be producing them somehow? Duty-cycle is close to rf-loop's.
You'll have to apply the divide and conquer technique. Have you tried to to make it work only with batteries? Completely removing the PSU and them then the DC/DC adaptor board, except the driver for the screen. But don't forget that the main board has other DC/DC converter, one power directly the entire DAC, digital and analog sections.
Sorry then not them!
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I'm not sure I understand what you're saying...
Do you want me to try to run the DAC board by using only an external power supply?
Right now, I only have one good linear "lab" power supply, with only one channel, so it will take me a while to make a PSU for -7.6 V and then to rig everything up so that it starts.
I was thinking about doing things the other way around and start by running the PSU with a dummy load and then probe with another scope (when I manage to arrange access to it), since that to me seems easier to do. I'm pretty sure that the noise source is in the PSU itself. Few pages ago, I tried out the PSU with adapter power cable disconnected and probed the -7.6 V with my soundcard. I still had the noise peaks with same frequency as the ones I'm seeing on the scope GND.
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Unfortunately, I haven't functional my scope. Pehaps some measurement to my circuit will help you.
Still, I am wait the AOZ1094 to arrived.
Carrington, the EMI shielding where you thinking to apply? Front or back of the screen and what dimensions we are need?
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Unfortunately, I haven't functional my scope. Pehaps some measurement to my circuit will help you.
Still, I am wait the AOZ1094 to arrived.
Carrington, the EMI shielding where you thinking to apply? Front or back of the screen and what dimensions we are need?
From, is as glass, but with a conductive coating.
https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/msg279474/#msg279474 (https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/msg279474/#msg279474)
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I'm not sure I understand what you're saying...
Do you want me to try to run the DAC board by using only an external power supply?
Right now, I only have one good linear "lab" power supply, with only one channel, so it will take me a while to make a PSU for -7.6 V and then to rig everything up so that it starts.
I was thinking about doing things the other way around and start by running the PSU with a dummy load and then probe with another scope (when I manage to arrange access to it), since that to me seems easier to do. I'm pretty sure that the noise source is in the PSU itself. Few pages ago, I tried out the PSU with adapter power cable disconnected and probed the -7.6 V with my soundcard. I still had the noise peaks with same frequency as the ones I'm seeing on the scope GND.
One good linear "lab" power supply, help. You can buy also fat batteries. -> ~ -7.6V
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Unfortunately, I haven't functional my scope. Pehaps some measurement to my circuit will help you.
Still, I am wait the AOZ1094 to arrived.
Carrington, the EMI shielding where you thinking to apply? Front or back of the screen and what dimensions we are need?
From, is as glass, but with a conductive coating.
https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/msg279474/#msg279474 (https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/msg279474/#msg279474)
I see, you are thinking to use it like a glass in front of tft display. I saw that you have done the same question to the Rigol DS2072 thread.
I''ll doing a search about this.
By the way, can someone to take a capture how display the scope a 40mVpp 100kHz sine wave at 1ms/div 10mV/div or 5mV/div? One channel and 10M memory depth. Please with scope with not gnd noise. Is there any aliasing?
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I see, you are thinking to use it like a glass in front of tft display. I saw that you have done the same question to the Rigol DS2072 thread.
I''ll doing a search about this.
That's right, but the conductive surface should be behind. And it can be checked only if someone have this side accessible, not my case. Although I think that it is a simple plastic.
https://www.eevblog.com/forum/testgear/first-impressions-and-review-of-the-rigol-ds2072-ds2000-series-dso/1650/ (https://www.eevblog.com/forum/testgear/first-impressions-and-review-of-the-rigol-ds2072-ds2000-series-dso/1650/)
The second image was obtained from this video:
http://www.eevblog.com/2012/09/26/eevblog-360-rigol-ds2000-oscilloscope-teardown/ (http://www.eevblog.com/2012/09/26/eevblog-360-rigol-ds2000-oscilloscope-teardown/)
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Hi TomC!
I forgot to show the general duty cycle and to write about the large peaks in the last post, so I updated it. Basically, the peaks are still there and they don't seem to be related to MC's operation. Could the TL431 be producing them somehow? Duty-cycle is close to rf-loop's.
AndrejaKo, looking at the captures on your updated post I notice there is a shift in frequency between them. You had the scope stopped when you made the capture, so I'm wondering if the shift is gradual or do you see a lot of jitter when looking at it dynamically?
It's difficult for me to imagine a scenario where the TL431 may be causing the noise, but anything is possible. However, I have to first suspect the -7.6V where there is a lot more dynamic activity going on. I looked at a PSU circuit board side picture you previously posted and added some notes, see attachment. It's possible that the noise you see around EC5 & EC8 is passed on from the MC area because of where the ground trace narrows next to R40 and the TL431. At some point when you have resolved this problem it may be a good idea to use a larger conductor there to improve GND noise in general. For now, I think that the source of the noise is in the MC area, possibly R40, or some other component. There is not very many and you already replaced the MC IC itself. If you have a resistor similar to R40 I would try replacing that next.
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I'm re-posting an animation I made few pages ago right now. It's purpose was to show how the frequency shifts look like. Basically there's around 20 ms between peaks, but they keep jumping around in the region of approximately 2 ms from the 20 ms point where I'd expect them. It's not all that visible on the animation, but peaks jump both to the left and to the right. Other than that, the animation faithfully shows what's happening on the screen of the oscilloscope and the peaks are jittery.
As for resistor replacement, most of the resistors of correct nominal value I can find easily are inductive, ceramic wire wound and I suspect that they would not be suitable. I could go for series combination of 3 resistors each marked 0.1 ohm, but that would exceed the value I need. Maybe 3 metal-film resistors in parallel, each with nominal value of 1.8 ohm? That would be pretty close. OK, I'm obviously too tired to calculate... :)
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Maybe 3 metal-film resistors in parallel, each with nominal value of 1.8 ohm? That would be pretty close. OK, I'm obviously too tired to calculate... :)
OK AndrejaKo, take a rest and will try again later (tomorrow). You'll need, seven 1.8 ohm in parallel (0.257 ohms) to come close to the value.
Edit:
When I mentioned frequency shift in my previous post, I meant the signal where you show the duty cycle, not the big noise spikes. Although the duty cycle looks a lot closer to the one rf-loop posted, I was wondering if there was jitter or a gradual change in frequency. On the first duty cycle capture I see a range from 43-50KHz, on the last capture I see a frequency below 38KHz. Also as you pointed out the duty cycle varies quite a bit.
If everything is working correctly and the converter is working in CCM the duty cycle is a function of the voltage in and voltage out approximately like this: DC = Vout / (Vin + Vout) If you work that out with Vin = 8.4V it comes out pretty close to 50%. Of course when you are using the battery it'll change some. But it shouldn't be changing back and forth from 40% to 60% as you reported.
The frequency is controlled by C6 which is charged and discharged by an internal current source and sink. The current values are fixed so the voltages in and out of the IC shouldn't affect the frequency. However, the charge current is increased to cause a short oscillator cycle if too much current is detected by the current sense circuit (which checks the voltage across R40). So if everything is working correctly the frequency should be pretty steady, going back and forth from 38KHz to 50KHz doesn't seem right to me.
In conclusion, I think something is still wrong. You replaced the IC and things got better, maybe because of slight differences in characteristics between the two ICs, but still there seems to be an underlying problem. If that gets fixed, maybe the old IC will also work correctly. Like I said before, there is only a handful of external components, and I think I would start with R40.
Note: The ON Semi application note for this IC states that you can disable the current sense circuit by connecting pin 7 to VCC. So for a test, it may be OK to short R40. I wouldn't do it for too long and would be watching for other components overheating. Up to you, if you want to risk it!
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By the way, can someone to take a capture how display the scope a 40mVpp 100kHz sine wave at 1ms/div 10mV/div or 5mV/div? One channel and 10M memory depth. Please with scope with not gnd noise. Is there any aliasing?
Here are some captures, I hope you don't consider my scope noisy :palm:
There is of course no aliasing at 1ms/div with 10M memory depth. I had to set the time base to 2s before I saw any aliasing.
Edit:
I made a big boo-boo when I captured these images. I connected the probe to the generator's ground, and the scope's ground lead to the generator's output. Miraculously I got something resembling a signal. Actually, when I first looked at it I saw big noise spikes, not quite as bad as AndrejaKo's but similar looking. Not yet realizing I had reversed the polarity I did a self calibration. After that the signals looked better so I captured the images and posted them. So I'm leaving them here as an example of what you get if you make this mistake. I'll post properly captured images in a separate post.
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By the way, can someone to take a capture how display the scope a 40mVpp 100kHz sine wave at 1ms/div 10mV/div or 5mV/div? One channel and 10M memory depth. Please with scope with not gnd noise. Is there any aliasing?
Here are the captures done correctly this time. There is no aliasing at 1ms/div with 10M memory depth and I still had to set the time base to 2s before I saw any aliasing.
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TomC many thanks for the captures.
When I saw your first captures, freak! The last ones is clearly without any alliases (and with triggering appearing right).
It is mine missing about how to connect with generator, probe or bnc-bnc (50 Ohm). Probably the true is bnc to bnc but author doesn't say...
The whole story held to Rigol DS2072 thread (https://www.eevblog.com/forum/testgear/first-impressions-and-review-of-the-rigol-ds2072-ds2000-series-dso/msg262688/#msg262688) that one member (Galaxyrise) ask the rest member how is it to the other scopes becouse the Rigol High-Res mode is so different from what his expected.
Then his demonstrate two captures with the same conditions like ask you, but I can't undestood why displaying that! I don't meaning about aliasing (it is there and the wave isn't stable) but with 10mV/div, it must to cover 4 div. I haven't experience about Rigol menu, but here something goes wrong. Maybe Carrington that has Rigol explaining that.
(https://www.eevblog.com/forum/testgear/first-impressions-and-review-of-the-rigol-ds2072-ds2000-series-dso/?action=dlattach;attach=55051;image)
(https://www.eevblog.com/forum/testgear/first-impressions-and-review-of-the-rigol-ds2072-ds2000-series-dso/?action=dlattach;attach=55053;image)
After some messages another member (Hydrawerk) (https://www.eevblog.com/forum/testgear/first-impressions-and-review-of-the-rigol-ds2072-ds2000-series-dso/msg276278/#msg276278) demonstrate the Agilent DSO-X-2002A results that is fine and clearly, but at two captures with different mem. depth doesn't capture the triggering right to one of them (remember TomC what told about this...). At this measurement the connection btw generator and scope is internall because has internal generator option.
(https://www.eevblog.com/forum/testgear/first-impressions-and-review-of-the-rigol-ds2072-ds2000-series-dso/?action=dlattach;attach=57529;image)
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First one thing I've noticed: With new regulator, both regulator and coil run much cooler than before. Previously I couldn't hold my finger next to them because of heat. Now they're just very hot, but not burning hot.
I did some scoping on the timing capacitor itself and its waveform is very noisy and jittery. According to the scope's frequency measurement, the frequency is always changing. It's usually around 48 kHz, but can go as high as 60 kHz sometimes. I'm attaching image with infinite persistence. Another image which I found interesting is when I probes the pin 2 and pin 3 at the same time. It seems that there are huge bursts of noise on pin 3 when pin 2 is high.
Should I try changing the capacitor? It seems like a polyester capacitor to me, but from what I heard they should be pretty good.
I can easily obtain ceramic multilayer capacitors of same capacitance and tolerance with NP0 dielectric and try with them, to see if it's the capacitor.
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The whole story held to Rigol DS2072 thread (https://www.eevblog.com/forum/testgear/first-impressions-and-review-of-the-rigol-ds2072-ds2000-series-dso/msg262688/#msg262688) that one member (Galaxyrise) ask the rest member how is it to the other scopes becouse the Rigol High-Res mode is so different from what his expected.
...
As I have understood, it occurs only in the HighRes mode, is more than evident. I suppose that it's a bug in the firmware, but I have no idea why it happens.
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@ AndrejaKo = I see a very well square at pin2, probably it is better than rf-loop.
I think that if I could to measure this point I hadn't better result.
@ Carrington = It is strange for me, not how this appears (about aliases or not stability in vertical axes) but why it hasn't four divisions at the Vertical axes.
At the first capture the Resolution is at the Auto and probalbly the Rigol set to maximum resolution but at the second capture the resolution set to lower 14kPoints about and the Vertical is only 1 div...10mV...why?
This is fw bug, sure.
Can you upload a capture with the same condition and another with some other resolution that dissapearing this phenomenon (of course at 40mV signal)?
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Hi lemon!
Someday I'll post a picture of my "lab" and you'll see that I have not much instrumentación. Not long ago I just had a simple multimeter. In this forum there are people who can afford (for whatever reasons) a lot of instrumentation, not my case. In this world everything is very badly distributed, and I have no hope that this will change.
Anyway, to this I need a signal generator, but I have not one. I'm thinking about where I can get a similar signal, and the only thing that comes to my mind now is ~20KHz of sound card.
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Don't worry about this, Carrington.
I'll do the same question to the Rigol thread.
TomC, sorry for this adding effort but at the first yours capture "1ms-Div.png" the sampling is 500MS not 1GS.
Can you see what it is happening? I want to upload this capture to the thread of Rigol.
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TomC, sorry for this adding effort but at the first yours capture "1ms-Div.png" the sampling is 500MS not 1GS.
Can you see what it is happening? I want to upload this capture to the thread of Rigol.
Lemon, I'm a retired man, I love playing with this stuff. Sometimes I have to help the wife with house shores, too keep her happy, but other than that I'm with the computers and the electronics.
What you see in the captures is normal for the SDS7102, as you use a slower time base, at some point (1ms/Div) the length of time that you are capturing doesn't fit in the memory (10M) at the maximum sampling rate (1GS) and the scope automatically lowers the sampling rate (500MS, etc.).
The confusing part about it is that when you stop the scope and look at the stored waveform, if you change the time base the sampling rate displayed changes as described above. But you are not capturing anything new, so the sampling rate can't possibly increase in reality. It's just the way the firmware implements it, it just looks at the current time base setting and the memory length and from that decides what sampling rate to display.
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First one thing I've noticed: With new regulator, both regulator and coil run much cooler than before. Previously I couldn't hold my finger next to them because of heat. Now they're just very hot, but not burning hot.
I did some scoping on the timing capacitor itself and its waveform is very noisy and jittery. According to the scope's frequency measurement, the frequency is always changing. It's usually around 48 kHz, but can go as high as 60 kHz sometimes. I'm attaching image with infinite persistence. Another image which I found interesting is when I probes the pin 2 and pin 3 at the same time. It seems that there are huge bursts of noise on pin 3 when pin 2 is high.
Should I try changing the capacitor? It seems like a polyester capacitor to me, but from what I heard they should be pretty good.
I can easily obtain ceramic multilayer capacitors of same capacitance and tolerance with NP0 dielectric and try with them, to see if it's the capacitor.
AndrejaKo, I need to look at these waveforms in more detail, they seem very interesting. Right now I have to run a 2 or 3 hour errand, but I'll give you more feedback when I come back. If you have a similar capacitor go ahead and change it, it'll be one less component to worry about. The capacitor's you propose should be good enough at least for a test.
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TomC very informative as always, thanks.
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AndrejaKo, I need to look at these waveforms in more detail, they seem very interesting. Right now I have to run a 2 or 3 hour errand, but I'll give you more feedback when I come back. If you have a similar capacitor go ahead and change it, it'll be one less component to worry about. The capacitor's you propose should be good enough at least for a test.
I changed the timing capacitor and there's more or less no difference, so I think that we can safely rule it out as the source of the problem.
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I changed the timing capacitor and there's more or less no difference, so I think that we can safely rule it out as the source of the problem.
Disconnect the circuit that generates the -7.6v, now use five 1.5v batt. in series or your linear PSU (better batt.), connecting the negative terminal to -7.6v point and the positive terminal to gnd, now turn on the oscilloscope using only your lithium battery. Continue appear those spikes?
Note: If you use your PSU don't dare to power it using the network (220V).
Do not worry, the oscilloscope "up" successfully even without the -7.6V. Although as is logical the input stage will not respond properly.
It not will be destroyed, I made the test on mine. Note that the -7.6v only power to the analog input stage through a LDO (7905).
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I changed the timing capacitor and there's more or less no difference, so I think that we can safely rule it out as the source of the problem.
Disconnect the circuit that generates the -7.6v, now use five 1.5v batt. in series or your linear PSU (better batt.), connecting the negative terminal to -7.6v point and the positive terminal to gnd, now turn on the oscilloscope using only your lithium battery. Continue appear those spikes?
Note: If you use your PSU don't dare to power it using the network (220V).
Do not worry, the oscilloscope "up" successfully even without the -7.6V. Although as is logical the input stage will not respond properly.
It not will be destroyed, I made the test on mine. Note that the -7.6v only power to the analog input stage through a LDO (7905).
I'll try that and report back the results.
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I got another lithium battery and connected it to the negative voltage terminal with the MC34063A removed and I got some extremely interesting results! All probing was done with a 150 MHz probe.
First, my conclusion is that those peaks which always occurred at around 20 ms seem to be under influence of at least two sources, one inside the scope and one on the outside!
I came to that conclusion when I noticed that the peaks seem to disappear for a short while when I was probing GND. After taking a look, it seems that they come in 600 ms bursts with 800 ms of pause between them. Inside of the burst the peaks occur at every 20 ms. They are illustrated in the first four attached images.
After moving the scope to my no electronics room, the large peaks disappeared. Now to refresh readers' memory, with the MC running and the scope in my no electronics room, I still had the peaks, so at least some of those peaks had to be coming from somewhere near the MC.
Anyway, in the no electronics room, I only got the smaller peaks I mentioned few times before. My guess is that they would be coming from the adapter board itself. They are illustrated in the last two images.
I also replaced PSU screws with higher quality ones an would recommend this small "upgrade" to anyone else who want to spend some time experimenting with this scope.
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AndrejaKo: Have you twisted the power cables (-7.6v)? And are they as short as possible?
After moving the scope to my no electronics room, the large peaks disappeared. Now to refresh readers' memory, with the MC running and the scope in my no electronics room, I still had the peaks, so at least some of those peaks had to be coming from somewhere near the MC.
Have you done the test without the MC in the "no electronics room"?
Anyway, in the no electronics room, I only got the smaller peaks I mentioned few times before. My guess is that they would be coming from the adapter board itself. They are illustrated in the last two images.
Well now I'm pretty sure that this noise comes from the adapter board. Please, show me a picture of this board.
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After moving the scope to my no electronics room, the large peaks disappeared. Now to refresh readers' memory, with the MC running and the scope in my no electronics room, I still had the peaks, so at least some of those peaks had to be coming from somewhere near the MC.
Very good! :-+
I think you are making considerable progress in unraveling this mystery!
Trying with batteries as Carrington suggested was a good fault isolation strategy that paid off!
I agree with your conclusion that this noise is very likely originating from more than one source. I would recommend that from now on any further tests be conducted in the no electronics room.
I think the next step is to re-install the MC IC and see if any of the high voltage spikes are still present, of course you must do this test in the no electronics room.
If the high voltage spikes are gone, perhaps you can shift the focus to cleaning up the remaining lower level noise.
You may also try to isolate the source of the high voltage spikes in the areas of the building where electronics are present. Part of this noise is probably conductive, and may be reaching the scope via the power plug, for that part you can try ferrites on the power cord. However, it appears that the bulk of it is radiated, since you have reported it while running the scope from the battery. That is more difficult to eradicate. First I would check for high voltage spikes with no probes attached to the BNC's, you may also want to try with 50 ohm terminators, both plugged in all the way and just acting as a shield cap with the center conductor not making contact. If there is little or no noise with these setups, is likely that the bulk of the high voltage spikes are making their way into the scope input via the probe cables. I think that's the more likely scenario, if it isn't, some of the EMI shielding products that Carrington is looking into to keep the scope from radiating EMI should be also as effective to keep external radiation from entering the scope.
My electronics lab is also my computer room, needless to say that there is often undesirable EMI radiation from multiple sources. These wasn't an issue with my 60MHz CROs, if I saw anything it was usually so faint that it was easily disregarded. With the 150MHz+ DSO is a different story. So to stop hunting ghosts I've been keeping ferrites on each end of my probe cables. I've found that the larger ferrites intended for power cables work the best because there is enough room to loop the probe cable an extra turn to double the inductance. So you can try and see if a setup like this helps with the high voltage noise spikes caused by your electronics.
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I agree with your conclusion that this noise is very likely originating from more than one source. I would recommend that from now on any further tests be conducted in the no electronics room.
Yes, please make all tests in the "no electronics room".
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@Carrington Yes, the test without the MC was done in the no electronics room. In future, I'll do all tests there. The adapter board is the standard 3.0 version board. So far, I did not make any modifications to the board itself, other than attaching ferrites to the cables. Also thanks for the encouragement to test this with batteries only. I needed it.
@TomC I'll get some ferrites for power cables and see if they help when running from AC. I'll report back when I'm finished testing with MC34063A reinserted.
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@Carrington Yes, the test without the MC was done in the no electronics room. In future, I'll do all tests there. The adapter board is the standard 3.0 version board. So far, I did not make any modifications to the board itself, other than attaching ferrites to the cables. Also thanks for the encouragement to test this with batteries only. I needed it.
Oh no the 3.0! Then most of this noise (of the attached image, ) comes only from the adapter board.
Now you know for sure that most of the "big noise" comes from the circuit associated with the MC.
Because this attached image is without the MC and in the "no electronics room", right?
Sorry, I made a little mess. ???
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Please, if you can try to make this changes.
https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/msg265881/#msg265881 (https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/msg265881/#msg265881)
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First one thing I've noticed: With new regulator, both regulator and coil run much cooler than before. Previously I couldn't hold my finger next to them because of heat. Now they're just very hot, but not burning hot.
I did some scoping on the timing capacitor itself and its waveform is very noisy and jittery. According to the scope's frequency measurement, the frequency is always changing. It's usually around 48 kHz, but can go as high as 60 kHz sometimes. I'm attaching image with infinite persistence. Another image which I found interesting is when I probes the pin 2 and pin 3 at the same time. It seems that there are huge bursts of noise on pin 3 when pin 2 is high.
Should I try changing the capacitor? It seems like a polyester capacitor to me, but from what I heard they should be pretty good.
I can easily obtain ceramic multilayer capacitors of same capacitance and tolerance with NP0 dielectric and try with them, to see if it's the capacitor.
I looked at these waveforms some more to try to come up with some kind of plausible scenario that explains what I see.
I think that the bursts when pin 2 is high are just the result of common mode noise interaction between the two probes, I don't know if you had each probe individually grounded, but if you didn't, that could have enhanced this interaction. This assessment is partly based on the fact that the first capture doesn't show these noise bursts. In addition, the same noise burst can be seen on the pin 2 waveform on a scale matching the V/div setting for that channel.
The one thing I find troubling is the irregularity of the duty cycle, and I'm just going to write what I'm thinking as I try to analyze why.
The large spike at the beginning of the capacitor's discharge cycle coincides with pin 2 going low, but it's not always the same size. It's size seems to depend on the length of time pin 2 remains high. I believe this spike represents D12 turning on due to L2's collapsing field and as a result charging EC8 to correct the output voltage. But why isn't it consistent.
I'm going to leave that aside for a second and look at what seems right. Pin 2 is supposed to go high during the charge time of the capacitor and nowhere else. It goes high when the output voltage has dropped a little as sensed by the IC's pin 5. This seems to be happening as it should, at some point during the charge cycle of C6 the output voltage drops a little bit and Bam, pin 2 goes high. In addition pin2 is supposed to go low at the beginning of C6's discharge cycle, and nowhere else, and it does that correctly too.
Back to what doesn't seem right. When pin 2 goes high late during C6's charge cycle, it goes off where it should (at the beginning of the discharge cycle), but the spike marking D12's turn on is not there, and pin 2 comes back on early during the next charge cycle. Why?
The only explanation I can think of is that EC8 didn't get enough charge and a voltage drop was detected by pin 5 again. Why?
A couple things I can think of, L2's collapsing field wasn't enough to forward bias D12 and charge EC8. Alternatively, D12's forward voltage is abnormal or inconsistent and fails to conduct and charge EC8 properly sometimes.
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Please, if you can try to make this changes.
https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/msg265881/#msg265881 (https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/msg265881/#msg265881)
I did the modifications and I got some improvement. The peaks went some 80 mV down.
Also would SR110 be a good replacement for SR160, if it turns out that the diode is broken? It has a bit higher forward voltage, but on the other hand, it has a bit lower capacitance.
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Please, if you can try to make this changes.
https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/msg265881/#msg265881 (https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/msg265881/#msg265881)
I did the modifications and I got some improvement. The peaks went some 80 mV down.
Although it has improved, but there is still too much noise. Why? ...
OK. Have your adapter board this inductance (red)?
https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/msg265555/#msg265555 (https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/msg265555/#msg265555)
If not, look for one, should be the same value as used by the DC/DC to generate the 5.6V.
Another option is a big ferrite bead (with very low r at DC and high z at 100MHz).
Please solder C45 in the place where was C36.
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Before mod this area of board, look to the datasheet of AOZ1094AI dc-dc convertor that produce the 5.6V.
Owon makes some adaptations from Ver. 3.0 to Ver. 3.2 Look at the attachment photo (left is 3.2, right is 3.0 version).
At the version 3.2 corrects the badly cutting of gnd that previous was made (point 1). Removed the smd capacitor C36 (point 2), adding a second inductor 5.6uH with some smd decoupling capacitors (point 3).
The changes was few and very easy to make but is not so simple, because at the version 3.0 the output of 5.6V divided at two parts, left to power the dc/dc convertor for led backlight, right to power the mainboard.
For this reason, needs to playing someone with any values of the second inductor.
Owon at ver. 3.0 after the production had some mod with adding by the hand, a 10uH inductor without any decoupling capacitors. It was enouph? No.
Additional, needs a more investigation about how react the turning of diode D127 to the output noise.
I had start to play with these before burn the aoz1094 and I am waiting for this, still!
(https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/?action=dlattach;attach=56963;image)
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@Carrington
My board does not have that inductor. The best ferrite I can find locally right now is this: http://uk.mouser.com/ProductDetail/Fastron/06H-751X-00/?qs=M6QbaWWGTbRusNci/XxFMA== (http://uk.mouser.com/ProductDetail/Fastron/06H-751X-00/?qs=M6QbaWWGTbRusNci/XxFMA==) Would that be good enough? I'll move the electrolytic and report back.
@lemon
I'm sorry, I don't understand your last sentence...
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My board does not have that inductor. The best ferrite I can find locally right now is this:
http://es.mouser.com/ProductDetail/Fastron/06H-751X-00 (http://es.mouser.com/ProductDetail/Fastron/06H-751X-00)
Is not valid, the maximum current is only one amp. 5A at least -> http://www.coilcraft.com/mss1278.cfm (http://www.coilcraft.com/mss1278.cfm)
But better use a ferrite bead: http://www.digikey.es/product-detail/en/HI2220T101R-10/240-2431-1-ND/806791, (http://www.digikey.es/product-detail/en/HI2220T101R-10/240-2431-1-ND/806791,) and make a "PI filter" with decoupling capacitors.
I'll move the electrolytic and report back.
Change C45(ceramic), not C44 (electrolytic).
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If these peaks (yellow) are around ~ 100MHz with the PI filter should attenuate. Is likely that the noise reach 50mV max.
But as lemon says, more improvements are needed, 50mV is too.
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Sorry, looks like I misread what yoy wrote about the capacitor.
Unfortunately, I can't find any ferrites that "advanced" here and import isn't the easiest thing (for example Digikey wants $120 for shipping).
Best thing I can get here would be a coil on toroidal base, for example Talema DPO--5.0-47. It's 47 µH, 5 A with resistance of 0.043 ohm. I'm not sure if I could actually attach it to the adapter board, since it's quite large and heavy.
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Have you considered the optional filter shown in the MC datasheet:
https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/msg278699/#msg278699 (https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/msg278699/#msg278699)
Additionally you can put another pi filter, look at attachments.
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Sorry, looks like I misread what yoy wrote about the capacitor.
Unfortunately, I can't find any ferrites that "advanced" here and import isn't the easiest thing (for example Digikey wants $120 for shipping).
Best thing I can get here would be a coil on toroidal base, for example Talema DPO--5.0-47. It's 47 µH, 5 A with resistance of 0.043 ohm. I'm not sure if I could actually attach it to the adapter board, since it's quite large and heavy.
Wow $120...
No electronic stores near you? As tme, farnell, rs or other.
Very big, and not valid: http://www.tme.eu/es/details/dpu047a5/choques-de-anilla/talema/dpo-50-47/ (http://www.tme.eu/es/details/dpu047a5/choques-de-anilla/talema/dpo-50-47/)
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I have local electronic stores (that's where I'm buying all of my components normally), but the stuff they have is usually very old. They are still mostly in the through-hole era and equipment for switch-mode power supplies isn't all that common here, especially if SMD or high currents are needed.
There are some distributors for say RS Components or Farnell etc. but they usually don't want to work with individuals at all and I don't have a company. Also from what I hear, companies here often import all the components themselves and skip local distributors completely. For a company, shipping costs and import fees aren't that bad, but for an individual it's difficult. Also there's the "culture shock". For example sometime last year a Farnell representative called me. He said that he was doing market research. One thing that was difficult for me to explain is that it's much cheaper to import things if they come over regular mail. For example, if I have over 50€ order coming via a courier, then I need to pay "forwarding" fees which are usually flat are usually 40€ to 60€ depending on the company doing that (and courier chooses the company) in addition to the regular VAT and customs. If the package is coming via post office, then they do that part and it usually costs just a couple of percents of shipment value.
Anyway enough off-topic for now! The location for that Pi filter is interesting. I'll see if I can somehow mount a ferrite there. I'll also measure the -7.6 V current and then pick a ferrite that can work with it.
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I understand... :(
You know, all this is bullshit, and the guilty is only OWON.
As we know the warranty does not cover this issue, but they also are reluctant to sell the adapter board, I have no idea why (anyone who says that this is not true then is a liar). Owon only support payment via transfer, Why? The bank earns more than the cost the two boards.
All this is ridiculous...
Or are all drunk or they think that are the owners. What is happening there?...
Sorry for my English.
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Also would SR110 be a good replacement for SR160, if it turns out that the diode is broken? It has a bit higher forward voltage, but on the other hand, it has a bit lower capacitance.
I took a look at the data sheet and I think it should work.
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@Carrington
My board does not have that inductor. The best ferrite I can find locally right now is this: http://uk.mouser.com/ProductDetail/Fastron/06H-751X-00/?qs=M6QbaWWGTbRusNci/XxFMA== (http://uk.mouser.com/ProductDetail/Fastron/06H-751X-00/?qs=M6QbaWWGTbRusNci/XxFMA==) Would that be good enough? I'll move the electrolytic and report back.
@lemon
I'm sorry, I don't understand your last sentence...
Before I burned my AOZ1094 I had bought from Farnell Export some inductors from 4.7-10 (>5A) to play with filtering at the second inductor. I think that the Farnell Export send to your country. Delivery is 2-3 days and the shipping is only a Freight Charge (UPS) about 4.5 pounds +VAT and nothing all. I can give you some links if you interesting.
Probably you meant the turn of diode?
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@lemon
I'm sorry, I don't understand your last sentence...
Lemon had a mishap about a week ago and burnt the chip he mentions, he's still waiting for a replacement part to fix his scope.
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@Carrington
My board does not have that inductor. The best ferrite I can find locally right now is this: http://uk.mouser.com/ProductDetail/Fastron/06H-751X-00/?qs=M6QbaWWGTbRusNci/XxFMA== (http://uk.mouser.com/ProductDetail/Fastron/06H-751X-00/?qs=M6QbaWWGTbRusNci/XxFMA==) Would that be good enough? I'll move the electrolytic and report back.
@lemon
I'm sorry, I don't understand your last sentence...
Before I burned my AOZ1094 I had bought from Farnell Export some inductors from 4.7-10 (>5A) to play with filtering at the second inductor. I think that the Farnell Export send to your country. Delivery is 2-3 days and the shipping is only a Freight Charge (UPS) about 4.5 pounds +VAT and nothing all. I can give you some links if you interesting.
Probably you meant the turn of diode?
Sorry Lemon, you and me must have been typing together, I didn't see you on the list of people viewing the subject and thought you had gone on break. Speaking about breaks, I'm going to take one now and go for a walk! :)
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@lemon
Well if the shipping is that low on Farnell Export (or somewhere in that range), then that would be great. What had me concerned is that when I try to order something from them, it tells me that I'll get shipping costs at a later date and that reminds me of saying "if you have to ask how much it costs, you can't afford it". I'd appreciate links for the inductors!
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Before 2-3 years, Farnell has another politics about exports, the total charging was bigger ... 11GBP +VAT.
I don't know if their politic depended about your region. The only minus about Farnell, is that they don't accept Payment by Paypal, only Visa/Mastercard and have the limit of 20GBP for odering.
Here is the links:
A range of inductors with 5-8A (http://export.farnell.com/jsp/search/browse.jsp?N=203354+110142568+110183420+110159386+110149227+110518806+110137987+110195030+110127393+110138074+110253174+110148665+110256597+110178599+110149219+110179294+110170385+110203035+110149206+110127401+110583924+110142566+110203907+110583540+110183493+110202375+110159245+110127328+110190461+110191205+110576650+110179909+110177487+110159199+110127778+110178959+110148689+110127399+110137814+110584152+110193553+110170368+110159420+110496017+110169977+110159739+110275416+110192008+110137776+110242926+110583334+110193765+110138336+110148677+110127166+110584784+110200875&No=0&getResults=true&appliedparametrics=true&locale=en_EX_DIRECTEXP&divisionLocale=en_EX&catalogId=&skipManufacturer=false&skipParametricAttributeId=&prevNValues=203354&mm=1002695|110142568|110200875,&filtersHidden=false&appliedHidden=false&autoApply=false&originalQueryURL=%2Fjsp%2Fsearch%2Fbrowse.jsp%3FN%3D203354%26No%3D0%26getResults%3Dtrue%26appliedparametrics%3Dtrue%26locale%3Den_EX_DIRECTEXP%26divisionLocale%3Den_EX%26catalogId%3D%26skipManufacturer%3Dfalse%26skipParametricAttributeId%3D%26prevNValues%3D203354)
Personally, I took the series of CoilCraft, look at Order Codes 2289056, 2289070, 2289071 e.t.c
http://export.farnell.com/jsp/search/productdetail.jsp?SKU=2289056 (http://export.farnell.com/jsp/search/productdetail.jsp?SKU=2289056)
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Here is the links:
http://export.farnell.com/jsp/search/productdetail.jsp?SKU=2289056 (http://export.farnell.com/jsp/search/productdetail.jsp?SKU=2289056)
0.0441ohm x 2A = 88.2mV of ripple
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Carrington the max DC Resistance "plays" with the value of inductor.
For example if you see the max DC Resistance of 2289070 (5.6uH) has 0.0258...somewhere to 50mV, but do you believe that Owon used better inductors than that?
Another, the size of inductors that Owon uses, are very small.
The second inductors (this was adding by the hand at some Ver. 3.0) is very small 6-7mm almost. It can;t to be 5A inductor with this size!
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If owon done it wrong us too?
Do not have Farnell SMD ferrite bead with 6 mohm and 5A?
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Look at the 2292389... is it OK?
It is the only that it have 0.006 Ohm
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Look at the 2292389... is it OK?
It is the only that it have 0.006 Ohm
Perfect. :-+
http://www.farnell.com/datasheets/1685727.pdf (http://www.farnell.com/datasheets/1685727.pdf)
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AndrejaKo: This remind you to anything?
RIGOL DS1102E Oscilloscope smart Trigger captures fast rise-time noise transients (https://www.youtube.com/watch?v=LZNPiTdvgPc#ws)
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AndrejaKo: This remind you to anything?
RIGOL DS1102E Oscilloscope smart Trigger captures fast rise-time noise transients (https://www.youtube.com/watch?v=LZNPiTdvgPc#ws)
I've seen that noise, and all I had to do is plug the brick on the same AC outlet as the SDS7102 while doing the GND noise test. No loop probe required!
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I've seen that noise, and all I had to do is plug the brick on the same AC outlet as the SDS7102 while doing the GND noise test. No loop probe required!
Yep, we do not need a loop probe! :-DD
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Yep, we do not need a loop probe! :-DD
At last!! :-+
Owon beats Rigol! :box:
Built in loop probe and noise synthesizer :clap:!
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AndrejaKo, although the discussion is old, have in mind the Siri's measurements on MC34063.
https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/930/ (https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/930/)
This measurement is from newer version of PSU: T115-N Rev 3. (partially SMD components but still single layer board).
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Lemon, any news on your AOZ1094 yet? I'm planning on opening my scope today and take some current measurements from the PSU. I need that to improvise some dummy loads for when I start scoping my old PSU.
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Unfortunately, no news about this.
Usually the shipment from China delays enough.
If you are lucky =10-14 days
If you are normal guy = 18-25
If you are no lucky (gantemis like Greek says) = over 30 days.
It shipped 10th of August...
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Unfortunately, no news about this.
Usually the shipment from China is long days ago.
If you are lucky =10-14 days
If you normal guy= 20-25
If you are no lucky (gantemis like Greek says) = over 30 days.
It shipped 10th of August...
If it makes you feel any better, I had a horrible experience with USPS. I ordered some stuff from Parallax and it usually gets here in two weeks. This time, it was sent on 11th June and came to my post office on 11th September.
Also thank you for linking to those measurements. Back when they were new, I was following the results, but in the meantime, I forgor about them completely. Lots of useful information is there!
By the way, the electrolytic capacitor on the adapter board is not low ESR, right? I could change it to a low ESR one without much problems. Perhaps that would help a little bit.
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I had forget them, too!
Today I am looking at the old messages and found (again) all these usefull information. After so many pages, it is difficult to remember all of these. I bookmark some of these to easy recovery.
I had measure only the electrolytic capacitors of psu not adapter.
I have changed the C44 electrolytic with other with low esr but I had no improvement, but my trials stopped cause AOZ1094.
I am going to start again, when arrived them.
We have the same adapter (Ver. 3.0) and have some information from Siri's measurements. He had the same version with us, and his works will help us a lot.
I am thinking to come back all my mods to adapter board to the original and starts again slowly step by step with AOZ1094 topology first.
As I read today what the Siri found, he suggested that with the AOZ1094 there is no way for improvement, only with linear dc convertor.
I don't know we''ll see...
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I measured the 8.4V and -7.6V supplies current today. While the scope was open I also captured some waveforms from pin 2 of the MC34063A IC. The results were as follows:
8.4V --- 2.2A - 2.22A
-7.6V --- 153.5mA after scope fully booted, 166mA while scope is booting.
The mains voltage during these tests was 125VAC. The scope does not have the battery option.
The 8.4V supply current was measured by obtaining the voltage drop between GND-B and GND-C. This is the voltage drop across parallel resistors R14/R14A/R14B with a total value of 0.0333 ohms. The voltage drop ranged between 73.5mV and 74mV. Using this method both the current used by the local -7.6V converter and the current used by the converters on the adapter board are taken into account.
The -7.6V supply current was measured by opening the circuit at the adapter cable and using an ammeter.
The attachments are the waveforms from pin 2 of the MC34063A IC.
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Now it is explaining why Owon put small size inductor to 5.5V path of adapter board.
With 2.5-3A inductor we are OK.
It is very stange to me why the power suplly of -7.6V is too noise, with it has only 170mA of max. current!
TomC, thanks for all these measurement.
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Now it is explaining why Owon put small size inductor to 5.5V path of adapter board.
With 2.5-3A inductor we are OK.
It is very stange to me why the power suplly of -7.6V is too noise, with it has only 170mA of max. current!
TomC, thanks for all these measurement.
It (-7.6V SMPS) is most crap design what is inside this scope, just this -7.6V SMPS. This can not understand - why. (I remember this - "perhaps designer have been drunk in this day")
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It is most crap design what is inside this scope, just this -7.6V SMPS. This can not understand - why. (I remember this - "perhaps designer have been drunk in this day")
You know what, if the "engineers/designer" was not drunk this scare me even more. ;)
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Now it is explaining why Owon put small size inductor to 5.5V path of adapter board.
With 2.5-3A inductor we are OK.
It is very stange to me why the power suplly of -7.6V is too noise, with it has only 170mA of max. current!
TomC, thanks for all these measurement.
Do whatever you want, I'm just saying that mohm x A = mV.
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Does anyone know a Pi filter calculator which lets user enter component values and then get output based on that? I've been thinking more and more about adding a Pi filter to the -7.6 rail on the adapter board and would like to play with some values. So far I've only found MATLAB's rfckt.lclowpasspi, but figuring out how it works is taking a while.
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http://www.calculatoredge.com/electronics/ch%20pi%20low%20pass.htm (http://www.calculatoredge.com/electronics/ch%20pi%20low%20pass.htm)
http://www.designers-guide.org/Design/bypassing.pdf (http://www.designers-guide.org/Design/bypassing.pdf)
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Does anyone know a Pi filter calculator which lets user enter component values and then get output based on that? I've been thinking more and more about adding a Pi filter to the -7.6 rail on the adapter board and would like to play with some values. So far I've only found MATLAB's rfckt.lclowpasspi, but figuring out how it works is taking a while.
They usually work the other way around, you input the specs and it gives you the components values. Here is a link to the latter in case you don't have one. Also, there is a pi filter already designed and recommended for that circuit, see datasheet in second link. Owon uses this filter on later version PSU boards.
http://www.calculatoredge.com/electronics/ch%20pi%20low%20pass.htm (http://www.calculatoredge.com/electronics/ch%20pi%20low%20pass.htm)
https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/msg278699/#msg278699 (https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/msg278699/#msg278699)
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Does anyone know a Pi filter calculator which lets user enter component values and then get output based on that? I've been thinking more and more about adding a Pi filter to the -7.6 rail on the adapter board and would like to play with some values. So far I've only found MATLAB's rfckt.lclowpasspi, but figuring out how it works is taking a while.
See at PM. ;)
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Now it is explaining why Owon put small size inductor to 5.5V path of adapter board.
With 2.5-3A inductor we are OK.
It is very stange to me why the power suplly of -7.6V is too noise, with it has only 170mA of max. current!
TomC, thanks for all these measurement.
Do whatever you want, I'm just saying that mohm x A = mV.
Carrington could you explaining this better? Why the law of Ohm is identical with the ripple of V?
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Thanks for the Pi filter help! What I actually wanted to do was to take some component values from stuff I have in my junkbox and then compare results. I'm aware of the filter in the MC datasheet and the component values from the later PSU.
It turns out that the version of MATLAB I have access to has GUI for that class which provides interesting output.
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Carrington could you explaining this better? Why the law of Ohm is identical with the ripple of V?
This obviously is not as simple. Decoupling capacitors are everywhere mitigating the voltage drop that occurs in the transient.
All the transients will not reach to this point*, but a current passing through a resistor will generate a voltage right? I think if less better. what do you think?
* The point is where we want put "the PI filter".
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Just some ramblings to help keep my brain focused!
- DC/DC converters produce fast changing signals.
- Fast changing signals have high frequency components.
- High frequencies are easily radiated and electromagnetically coupled or conductively coupled through stray capacitance.
- When this is allowed to happen common mode signals are produced.
- Fast changing signals can be rendered harmless when their dissipation is confined to the circuit producing them.
- Striving for this goal is the best defense against common mode noise.
- Existing circuits can be altered sometimes to mitigate blunders in this area.
- Providing short low impedance paths to complete the circuit discourages radiated and capacitive coupling as alternative paths to complete the circuit.
- Keeping other circuits at a safe prudent physical distance can also help discourage alternative paths.
- When all else fails wholesale mitigation techniques such as decoupling capacitors, ferrite cores, and similar strategies are commonly used.
- Since at this point the common mode noise is usually widespread these strategies are seldom completely effective.
Any other thoughts, additions, or deletions?
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Here is a complete set of images for the MC34063A that I just captured. The subject PSU is installed in the same scope used to capture the waveforms and is the new PSU released by Owon. Because of the cramped conditions I had to use the long ground leads, and for some captures and additional 2" wire to connect the probe tip to some of the IC's pins. However, the probe cables are equipped with ferrite cores which should counteract some of the effect of the long ground leads. On all captures CH1 is attached to pin 2 of the MC (Switch Emitter) and is used as the trigger source. CH2 was used to view the signals on all the other pins. In most cases there is a capture using DC coupling, so that the voltage levels can be read, and one or more captures using AC coupling to show a more detailed image of noise and spikes. There are also captures with CH2 connected to pin 4 of the adapter cable (-7.6V to adapter).
#1 - Shows the relationship between pin 2 and the timing capacitor.
#2 - Shows the voltage at the IC end of the current sense resistor. The voltage during pin 2 low is 8.4V, and ramps down about 200mV when pin 2 is high. If this voltage reaches 330mV it shortens the duty cycle to prevent damage. However, as can be seen, this doesn't happen during normal operation.
#3 & 4 - Shows the 8.4V as it appears on pin 6 of the MC.
#5 thru 7 - Shows the 7.6V as it appears on pin 4 of the MC. This is before it's filtered by L3 and EC9.
#8 & 9 - Shows the 7.6V as it appears on pin 4 of the PSU to adapter cable, adapter side of the cable.
#10 thru 13 - Shows the relationship between pin 2 and the COMP input. This pin is very sensitive and as can be seen, probing it alters the operation of the MC IC.
#14 thru 17 - Shows that the operation of the MC IC is altered even when just a 2" piece of wire is attached to the COMP pin. I fear that this extreme sensitivity can spell trouble if there is a high level of EMI nearby even if nothing is attached to this pin.
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AndrejaKo,
in the set of captures I just posted I obtained some images that look similar to what your MC looks like. It turns out that pin 5 of that IC is very sensitive and just a short piece of wire attached to it causes havoc with the duty cycle. I observed the frequency go down to about 48KHz at times, which is similar to what you have. Looking at images of PSU boards similar to yours it seems that the resistors attached to that pin are thru hole labeled R40 & R37 located right next to the power switch housing. I would undo anything you have done in that vicinity, including the cutting of the ground traces that connected the switch housing to ground. Also, looking at a picture of your board's printed circuit side, I see some kind of residues in that vicinity, see attachment, I would thoroughly clean that up and undo any mods you may have done in that vicinity.
Good Luck! :)
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There is 08.March.2013 published modification prototype version 2b for PSU version PCB-T115-N REV3.
This is -7.6V circuit. There is not this problem.
Of course for other versions it is only principle and need carefully look how to apply it for other versions (before Owon made new supply).
One main question was, why this circuit disturb itself and of course this common mode radiated/conducted noise what was one part of total noise sum.
Also note that this version works well with original electrolytics in this circuit.
It need note that also some added capacitors positions are critical. One example can see in picture where I have removed one added capacitor and moved it right around 10mm. (C in orange box)
In this mod 2b all is not optimal. But it works. Of course it need some experiments with other board versions but I think it give good start point what to do. I think, in these now showed test results there is not used any these modifications. If there is, then some capacitor is broken. With these modifications can not get these results what I see now there in signal pictures.
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AndrejaKo,
in the set of captures I just posted I obtained some images that look similar to what your MC looks like. It turns out that pin 5 of that IC is very sensitive and just a short piece of wire attached to it causes havoc with the duty cycle. I observed the frequency go down to about 48KHz at times, which is similar to what you have. Looking at images of PSU boards similar to yours it seems that the resistors attached to that pin are thru hole labeled R40 & R37 located right next to the power switch housing. I would undo anything you have done in that vicinity, including the cutting of the ground traces that connected the switch housing to ground. Also, looking at a picture of your board's printed circuit side, I see some kind of residues in that vicinity, see attachment, I would thoroughly clean that up and undo any mods you may have done in that vicinity.
Good Luck! :)
At this moment, the PCB itself is clean from contamination (it was completely covered in flux residue when I first opened the scope) and there are no modifications close to the comparator pin of the MC right now. Also instead of cutting ground, I disconnected the switch's cover from the GND.
In any case, I don't believe that any modifications affected the MC duty cycle issue. It was erratic even before any of the modifications, so I'm convinced that they're mostly influenced by bad layout. I'll see if I can post a picture of the PSU with current modifications.
Unfortunately, I have to stop my experiments for a while. I have some exams in the next two weeks for which I need to prepare and fixing the noise is currently draining too much of my resources.
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I think, in these now showed test results there is not used any these modifications. If there is, then some capacitor is broken. With these modifications can not get these results what I see now there in signal pictures.
rf-loop,
These are test results with the new Owon PSU. Everything works OK as long as there is nothing connected to pin 5, the bad duty cycle captures are with a probe or a 2" wire attached to pin 5 which acts as an antenna. Of course, I don't think it should be so sensitive, but it works OK as long as you don't attach anything extra to it. I suspect that the Owon engineer used resistors with too high a value for the voltage divider, probably to try to prevent power losses. Maybe lower value resistors with the same ratio would make this pin less sensitive.
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Unfortunately, I have to stop my experiments for a while. I have some exams in the next two weeks for which I need to prepare and fixing the noise is currently draining too much of my resources.
Good luck with your exams, that comes first! :-+
There'll be plenty of time later on to play! :)
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I think, in these now showed test results there is not used any these modifications. If there is, then some capacitor is broken. With these modifications can not get these results what I see now there in signal pictures.
rf-loop,
These are test results with the new Owon PSU. Everything works OK as long as there is nothing connected to pin 5, the bad duty cycle captures are with a probe or a 2" wire attached to pin 5 which acts as an antenna. Of course, I don't think it should be so sensitive, but it works OK as long as you don't attach anything extra to it. I suspect that the Owon engineer used resistors with too high a value for the voltage divider, probably to try to prevent power losses. Maybe lower value resistors with the same ratio would make this pin less sensitive.
earlier version (not know exactly what version this changed)
resistors was much lower value. Around 180 and 910ohm.
This output capacitor need also RF bypass C.
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Today I started taking a look at the 8.4V converter. I found some surprises in the results and challenges in trying to scope them. The attachments are a set of signals I captured while scoping Q1's drain and D8's anode. Note that these captures are from the new Owon PSU that is currently installed in my scope.
The main challenge was dealing with the signal references, Q1 is in the primary side and is referenced to GND-A, D8 is in the secondary side and is referenced to GND-B. Note that connecting a ground lead to GND-A would cause a short circuit and as a minimum will blow the fuse, so that is out of the question. Connecting a ground lead to GND-B is not a good idea either, it probably wouldn't be catastrophic, but it will short out the CC current sense resistors (R14/R14A/R14B). So the only option is using GND-C which is also Chassis gnd. GND-C is separated from GND-B by no more than 125mV, so it's a fair reference for D8. However, it's a different story for Q1, because GND-A is nearly the same as GND-C half the time, but separated from it by 100s of volts the other half, it depends where on the mains AC cycle you are at. However, this knowledge is helpful, because you can focus on just the waveforms during the time that GND-A is nearly the same as GND-C and ignore the rest. Just use, for example, single trigger, until you capture something with the correct baseline.
Some of the captures were done while I powered the scope with my Variac. I wanted to see the effect of different mains voltages, and using the Variac I was able to vary the voltage between 100VAC and 140VAC. Unfortunately my Variac is almost as old as me and doesn't have a ground lug on it's power cord or on its output outlet. So I had to operate the scope without a ground and that changes the way GND-A is referenced. In this case it is floating in respect to GND-C and the signals referenced to it act as if the scope channel was AC coupled. So for those captures I manually set the signal's ground base line to the third graticule below the x axis. Of course in these cases the channel's ground marker should be ignored.
The surprises include the frequency, which varies depending on the mains voltage, and the converter's operation mode, which is CCM at low mains voltages, is in transition at around 120VAC, and is DCM at higher voltages.
#1 - Shows the effect of GND-A on Q1's signal. For this capture the scope was directly connected to the earthed mains (120VAC) and the persistence was set to 1s.
#2 & 3 - Shows that at 120VAC the operating mode is in transition, sometimes CCM, some times DCM. Also note the frequency, at 120VAC it's around 58KHz, even though the R7731A is programmed to operate at 65KHz.
#4 thru #9 - These were obtained using the Variac, and show the effect of the mains voltage on the operating mode. Also note the change in frequency. At 100VAC it's 65KHz and as the mains voltage increase the frequency decreases, the last image (140VAC) has a frequency of 56KHz.
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...
The main challenge was dealing with the signal references, Q1 is in the primary side and is referenced to GND-A, D8 is in the secondary side and is referenced to GND-B. Note that connecting a ground lead to GND-A would cause a short circuit and as a minimum will blow the fuse, so that is out of the question. Connecting a ground lead to GND-B is not a good idea either, it probably wouldn't be catastrophic, but it will short out the CC current sense resistors (R14/R14A/R14B). So the only option is using GND-C which is also Chassis gnd. GND-C is separated from GND-B by no more than 125mV, so it's a fair reference for D8. However, it's a different story for Q1, because GND-A is nearly the same as GND-C half the time, but separated from it by 100s of volts the other half, it depends where on the mains AC cycle you are at. However, this knowledge is helpful, because you can focus on just the waveforms during the time that GND-A is nearly the same as GND-C and ignore the rest. Just use, for example, single trigger, until you capture something with the correct baseline.
...
TomC, you done very well documentation but I have confused a little.
Because I remember the blow of R7731 that I had before. I had the ground clip (multimeter) to Z-plate ... (230Vac).
From what I read the GND-A and GND-C is almost identical (they are connected to Z-plate together) but it is better to use only the GND-C or Z-plate.
Please, where was the probe ground clip at your measurement on Q1 and where was at the D8?
Note= the AOZ1094 has received and everything is OK.
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About flyback freq. Did you note any Vdd variations related to AC powerline variations?
(R7731 freq is some amount sensitive for Vdd (and of course also temp) specially under 15V)
btw, what is this newest PSU version number?
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...
btw, what is this newest PSU version number?
Don't laugh ( :-DD), there isn't version number on it.
TomC here (https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/msg273905/#msg273905) has upload some photos of upper and bottom of this psu.
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TomC, you done very well documentation but I have confused a little.
Because I remember the blow of R7731 that I had before. I had the ground clip (multimeter) to Z-plate ... (230Vac).
From what I read the GND-A and GND-C is almost identical (they are connected to Z-plate together) but it is better to use only the GND-C or Z-plate.
Please, where was the probe ground clip at your measurement on Q1 and where was at the D8?
Note= the AOZ1094 has received and everything is OK.
Lemon, I'm really happy that your scope is fixed! :-+ Congratulations! :)
The ground leads for both probes were connected to GND-C (Z-plate) at all times. Please, don't connect the ground lead to GND-A, it's not connected to the Z-plate, and it will cause a short circuit similar to what you had before. See attachment, it shows what happens if you do this!
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About flyback freq. Did you note any Vdd variations related to AC powerline variations?
(R7731 freq is some amount sensitive for Vdd (and of course also temp) specially under 15V)
btw, what is this newest PSU version number?
rf-loop,
I didn't check the IC's VDD during these tests, I will be doing that on the next set of tests. Theoretically, I don't expect significant variations, but I should know better than making theoretical predictions! Let's see if I get another surprise.
As Lemon said, Owon hadn't printed a version number on the new PSU board as of the date they shipped mine.
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Today I only had time to measure the VDD pin of the R7731A with different mains voltages. The easiest way to do this is with a voltmeter, the ground probe on GND-A (Q1's heatsink), and the red probe on the cathode of D6 (which is connected to the VDD pin). Fortunately this time there were no surprises. The results were as follows:
100VAC mains --- 16.58VDC
140VAC mains --- 16.66VDC
I also wanted to view this voltage with the scope, however, this is not quite as easy. The problem once again is that if you connect the scope's ground lead to GND-A there is a short circuit. So again, I had to connect the ground leads to GND-C. I then connected CH1 to GND-A, and CH2 to the VDD pin. Then I used the math function CH2 - CH1 to view the voltage. The captures were done while I powered the scope with my Variac, and this time I improvised an earth ground connection so GND-A wouldn't be floating in respect to GND-C.
Note that when you scope anything on the primary side with the scope referenced to GND-C, the signals you see are riding on a 50/60Hz half wave rectified AC signal. This is normal, because GND-A is connected to GND-C via the rectifier diode D4. So that's the reason the attachments look the way they do. Nevertheless, the difference between the two signals is the voltage in question.
To keep the two signals within the confines of the screen I have then overlapping each other in some captures. In those cases it seems that only channel 2 is in the picture, however, CH1 is just hidden underneath. If either one of the signal is partially off screen the measurements are not accurate. This is illustrated on the last attachment.
#1 - Shows the VDD voltage with 100VAC mains, in this capture the signals are not overlapping and since they are referenced to the same vertical division you can visually see and measure the voltage difference between them.
#2 - This is the same as #1 but the signals are overlapping.
#3 - Shows the VDD voltage with 140VAC mains, in this capture the signals are overlapping and since they are not referenced to the same vertical division you can't visually see and measure the voltage difference between them.
#4 - This is the same as #3 but the signals are not overlapping. It shows the problem with accuracy when signals are too large for the screen.
Note that the cursors used to get the average math trace voltage use CH1's V/Div scale. You can't select math as the source for the cursors, one more thing I wish Owon would fix. As a result, since CH1 is set to 20V/Div, you have to divide by 10 to match the Math 2V/Div setting. This yields a voltage reading of 16.4V.
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Without differential probe these measurenments are difficult, and also controller chip internal smoke leaks easy out and without internal smoke it can not work.
Later I will check also some things after I upgrade some scopes with new PSU and Adapter boards and I hope I have then time for do some mesurements.
There is coming some new, and I think, Owon have also learned something.
--------
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Today I only had time to measure the VDD pin of the R7731A with different mains voltages. The easiest way to do this is with a voltmeter, the ground probe on GND-A (Q1's heatsink), and the red probe on the cathode of D6 (which is connected to the VDD pin). Fortunately this time there were no surprises. The results were as follows:
100VAC mains --- 16.58VDC
140VAC mains --- 16.66VDC
...
Also, I have done a measurement to R7731N (socket dip-8) on PCB-T115-J Rev6 with 230Vac mains (50Hz) and the Vdd was 18.09Vdc after a half an hour of operation. Starts cold with 18.5 almost and slowly stabilized to 18.09Vdc
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Also, I have done a measurement to R7731N (socket dip-8) on PCB-T115-J Rev6 with 230Vac mains (50Hz) and the Vdd was 18.09Vdc after a half an hour of operation. Starts cold with 18.5 almost and slowly stabilized to 18.09Vdc
That's interesting, I wonder if the difference in voltage from the R7731A is due to the higher mains voltage or something else, like for example, a slightly different flyback transformer.
Lemon, if you got some time, could you capture waveforms of Q1 & D8 like I did in my previous post. I would like to see what they look like at 230VAC. I don't have a suitable step up transformer to do this myself.
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TomC, with my pleasure but confirmed please the connections to my attachment photo.
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TomC, with my pleasure but confirmed please the connections to my attachment photo.
Lemon, that's the correct connections to measure the VDD of the R7731N IC with the scope, you can post that too for a more complete set of measurements. However, the capture I had in mind was for Q1 and D8 like in this previous post:
https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/msg282577/#msg282577 (https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/msg282577/#msg282577)
I was just mowing and I'm away from the lab for a little while (I'm using the laptop from the garage and I'm not allowed in the house until I clean up). As soon as I come in I'll give you more detailed instructions on how to connect the scope.
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OK, TomC take your time that you are needing and I am here to measure whatever you want.
I prepare a work about AZ1094 circuit...it has a lot of interesting!
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Well, as I have told before, I was thinking to search about AOZ1094AI circuits. All we know that this dc-dc converter takes the 8.4V from PSU board and convert to 5.6V output.
Before, I analyze the circuit and see how this various components effect the output noise, I've done some measurements to have them as reference. All these measurements is from modificate version 3.0 as described here before. (https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/msg271798/#msg271798).
# Sample ref = is the gnd noise with Sample Acq. Method. Range 40-52mV
# Peak ref = is the gnd noise with Peak Acq. Method. Range 40-52mV
# Average ref = is the gnd noise with Average (16) Acq. Method. Range 30-34mV, the noise is smaller (<28mV) if time base set to 500usec vs 100usec.
# Noise 5.6 ref = is the noise at output of 5.6V (it has measured with short gnd clip at the second inductor position).
# L3_ref = is the wave captured on L3 inductor (on air)
# D127_ref = is the wave captured on D127 diode (on air)
# AOZ1094_ref = is the wave captured on IC 1094 (on air)
(it continues...)
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OK, TomC take your time that you are needing and I am here to measure whatever you want.
I prepare a work about AZ1094 circuit...it has a lot of interesting!
That'll be interesting!
Your PSU board is different from mine, so I attached images of where I think it'll be easiest to hook up the probes. CH1 should be on D8's anode, and CH2 on Q1's drain. Both ground leads to the Z-plate. Make sure the probes are set to X10 because the peak voltage at Q1's drain may be more than 400V with 230VAC mains. While the scope is running you'll see an image like #1, jumping up and down. When the baseline of the CH2 trace is level with the ground marker it is as closely referenced to the Z-plate ground as you can get. To get a capture like #2 I used single trigger. Sometimes the baseline will be at the correct place, so when this happens I capture the image.
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I returned back all the relate circuit about AOZ1094 to factory setup and take an output noise measurement on 2nd inductor position (right photo mark 3).
For the measurement, I used a short gnd clip.
Attention the initial version 3.0 there isn't 10uH inductor at this position, this inductor was adding by Owon (with the hand) after.
(https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/?action=dlattach;attach=56963;image)
# Output Noise 5.6, with factory setup, no 2nd inductor = Ohh, what is difference and what peaks are they? Sure the designer was drunk! From 36.8mV jumped to 93.6mV!
The second wave (yellow) is the gnd-noise, both of tip and gnd grip on Z-plate.
(it continues...)
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Before I continue, must analyze a little the topology of circuits and marks the differences with adapter version 3.2
I repeat the above compare photo btw the two adapter versions for easy. Left is version 3.2, right the version 3.0
(https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/?action=dlattach;attach=56963;image)
As we can see, at the version 3.2 has corrected the badly routing and cutting of ground planes that previous version was made (point 1).
Removed the smd capacitor C36 (point 2), thus adding a second inductor 5.6uH with some smd decoupling capacitors (point 3).
The worst all of this is the badly ground plane routing. For this reason, the member Siri had suggested the return of diode D127. The member Carrington had suggested the joined btw the two parts of ground plane. Both of them have the same effort to output noise. Both of them connect the two ground parts to one.
Following photo shows how this joined effects the output noise to 5.6V path. Very well, 41.6mV from 93.6mV only with better ground plane, closely to 36.8mV ref. measurement.
The second wave (yellow) is the gnd-noise, both of tip and gnd grip on Z-plate.
(it continues...)
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Following photo shows how this joined effects the output noise to 5.6V path. Very well, 41.6mV from 93.6mV only with better ground plane, closely to 36.8mV ref. measurement.
The second wave (yellow) is the gnd-noise, both of tip and gnd grip on Z-plate.
(it continues...)
Very interesting! :-+
I'm wondering why you are using 20mV/Div (restricts bandwidth to 20MHz), are the signals too small if you use 50mV/Div?
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Today I wanted to measure the ripple and peak voltage at the output of the unregulated supply. This is best viewed with a scope. Once again, as in post #1817, the scope's ground lead can't be connected to GND-A. So the ground leads are connected to GND-C, CH1 is connected to GND-A, and CH2 is connected to the cathode of D1. Again the math function CH2 - CH1 is used to view the signal. The captures were done while I powered the scope with my Variac, again using an improvised earth ground connection so GND-A wouldn't be floating in respect to GND-C.
#1 Shows the peak voltage & ripple with 100VAC mains.
#2 Shows the peak voltage & ripple with 125VAC mains.
#3 Shows the peak voltage & ripple with 140VAC mains.
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OK, TomC take your time that you are needing and I am here to measure whatever you want.
I prepare a work about AZ1094 circuit...it has a lot of interesting!
That'll be interesting!
Your PSU board is different from mine, so I attached images of where I think it'll be easiest to hook up the probes. CH1 should be on D8's anode, and CH2 on Q1's drain. Both ground leads to the Z-plate. Make sure the probes are set to X10 because the peak voltage at Q1's drain may be more than 400V with 230VAC mains. While the scope is running you'll see an image like #1, jumping up and down. When the baseline of the CH2 trace is level with the ground marker it is as closely referenced to the Z-plate ground as you can get. To get a capture like #2 I used single trigger. Sometimes the baseline will be at the correct place, so when this happens I capture the image.
TomC, thanks for helping...
Here it is what you ask.
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Following photo shows how this joined effects the output noise to 5.6V path. Very well, 41.6mV from 93.6mV only with better ground plane, closely to 36.8mV ref. measurement.
The second wave (yellow) is the gnd-noise, both of tip and gnd grip on Z-plate.
(it continues...)
Very interesting! :-+
I'm wondering why you are using 20mV/Div (restricts bandwidth to 20MHz), are the signals too small if you use 50mV/Div?
Your thought is right, this is my |O. Unfortunately I haven't the reference noise with full BW but I'll see after...
Again some captures with full BW.
There is D217 180° turn at the two captures, at the first there is no any 2nd inductor, at the second there is a 10uH inductor like Owon does by hand.
The result at the second captures is worst and I don't know who from Owon thought that solution!
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I think is time to analyze the circuit according to datasheet and evaluation schematic board.
I have enclosed two attachment schematic, the typical and the evaluation.
The Vin (pin1) of AOZ1094 demands some decoupling capacitors. The typical has 22uF electr. caps, the evaluation has two 22uF electr. caps parallel. Owon has a 100uF electr. with two parallel smd caps (C33, C95) with unkown values. I think there is a need to measure the noise and ripple at that position (at the end of C33 caps).
The pin6 is enable pin, Owon just connect with Vin, typical and evaluate schematic set a 1nF decoupling capacitor. I believe that this must adding.
The pin5 is external loop compensation pin. Here the datasheets seems to be identical with the choice of Owon. The evaluate schematic set the position C7 open for tuning (?).
The pin2 & 3 are two grounds, digital and analogue respectively.
The pin4 is used to determine the output voltage via a resistor divider between the output
and GND FB pin. Here the choice of Owon is good with one resistor more adding at the output (R21). The evaluate schematic set the position C8 open for tuning.
The pin7 & 8 are joined together. From this point Owon puts the D127 to gnd and through the L3 inductor with 3 caps parallel, C36/5uF, C45/12uF and C44/470uF.
This way differs some from evaluate schematic. At the evaluate schematic there is RC parallel to D127 and at the output there are two electr. caps of 22uF. I think that needs 1uF smd parallel to diode. The output needs more investigation with two inductors or pi filters.
(https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/?action=dlattach;attach=56963;image)
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OK, TomC take your time that you are needing and I am here to measure whatever you want.
I prepare a work about AZ1094 circuit...it has a lot of interesting!
That'll be interesting!
Your PSU board is different from mine, so I attached images of where I think it'll be easiest to hook up the probes. CH1 should be on D8's anode, and CH2 on Q1's drain. Both ground leads to the Z-plate. Make sure the probes are set to X10 because the peak voltage at Q1's drain may be more than 400V with 230VAC mains. While the scope is running you'll see an image like #1, jumping up and down. When the baseline of the CH2 trace is level with the ground marker it is as closely referenced to the Z-plate ground as you can get. To get a capture like #2 I used single trigger. Sometimes the baseline will be at the correct place, so when this happens I capture the image.
TomC, thanks for helping...
Here it is what you ask.
Thanks a lot for these captures! :-+
They answer some questions I've been wondering about, and pose some new ones!
New question --- The frequency of your 8.4V converter is about 62.6KHz at 230VAC. Compared to the frequency change on mine as the mains voltage was increasing (frequency decreasing as voltage increased), it seems that your PSU stays close to the 65KHz programmed frequency. Why? Is this because of a difference between the R7731N and the R7731A? Is it because my R7731A is flaky? Maybe I can find the answer when I test my old PSU......
Answered question --- The peak voltage at Q1's drain is about 462V. Q1's breakdown voltage is 600V. It seems that the designers allowed a fair safety margin.
A reminder to SDS series users:
The scope's maximum input voltage spec is 400V. While testing voltages in excess of this spec you should insure the probe is set to X10 to protect the scope's input. Also remember that the supplied probes have a maximum rating of 600V. If you need to test anything higher you should use a high voltage probe.
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The pin6 is enable pin, Owon just connect with Vin, typical and evaluate schematic set a 1nF decoupling capacitor. I believe that this must adding.
It seems that this IC's output could be delayed via this pin if necessary, Owon didn't use this feature and enables it as soon as Vin is available.
The pin7 & 8 are joined together. From this point Owon puts the D127 to gnd and through the L3 inductor with 3 caps parallel, C36/5uF, C45/12uF and C44/470uF.
This way differs some from evaluate schematic. At the evaluate schematic there is RC parallel to D127 and at the output there are two electr. caps of 22uF. I think that needs 1uF smd parallel to diode. The output needs more investigation with two inductors or pi filters.
The RC is probably a snubber. Perhaps you can scope the waveform at D127's cathode to see if there is excessive ringing. If there is ringing a snubber can help.
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at the second there is a 10uH inductor like Owon does by hand.
The result at the second captures is worst and I don't know who from Owon thinking that solution!
It seems like the inductor is forming a resonant circuit with stray capacitance, causing all the extra noise you see on the captured image. Perhaps adding an appropriate capacitor in pi arrangement (as you mention in next post) may stop the ringing and give better noise results.
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OK, TomC take your time that you are needing and I am here to measure whatever you want.
I prepare a work about AZ1094 circuit...it has a lot of interesting!
That'll be interesting!
Your PSU board is different from mine, so I attached images of where I think it'll be easiest to hook up the probes. CH1 should be on D8's anode, and CH2 on Q1's drain. Both ground leads to the Z-plate. Make sure the probes are set to X10 because the peak voltage at Q1's drain may be more than 400V with 230VAC mains. While the scope is running you'll see an image like #1, jumping up and down. When the baseline of the CH2 trace is level with the ground marker it is as closely referenced to the Z-plate ground as you can get. To get a capture like #2 I used single trigger. Sometimes the baseline will be at the correct place, so when this happens I capture the image.
TomC, thanks for helping...
Here it is what you ask.
Thanks a lot for these captures! :-+
They answer some questions I've been wondering about, and pose some new ones!
New question --- The frequency of your 8.4V converter is about 62.6KHz at 230VAC. Compared to the frequency change on mine as the mains voltage was increasing (frequency decreasing as voltage increased), it seems that your PSU stays close to the 65KHz programmed frequency. Why? Is this because of a difference between the R7731N and the R7731A? Is it because my R7731A is flaky? Maybe I can find the answer when I test my old PSU......
Answered question --- The peak voltage at Q1's drain is about 462V. Q1's breakdown voltage is 600V. It seems that the designers allowed a fair safety margin.
A reminder to SDS series users:
The scope's maximum input voltage spec is 400V. While testing voltages in excess of this spec you should insure the probe is set to X10 to protect the scope's input. Also remember that the supplied probes have a maximum rating of 600V. If you need to test anything higher you should use a high voltage probe.
There is no any information at the datasheet about differences btw sot-26/dip-8 that explains this different behaviour on frequency (except power dissipation and Package Thermal Resistance).
Unfortunately, I have no any comparing about your schematics and my psu circuit for some difference...
General, the range of frequency operation from 50-130KHz is normal.
About the maximum input voltage. I don't remember well but I think that the maximum of 400V is the adding of ac/dc components of singal and peak to peak not rms or average.
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at the second there is a 10uH inductor like Owon does by hand.
The result at the second captures is worst and I don't know who from Owon thinking that solution!
It seems like the inductor is forming a resonant circuit with stray capacitance, causing all the extra noise you see on the captured image. Perhaps adding an appropriate capacitor in pi arrangement (as you mention in next post) may stop the ringing and give better noise results.
Yeap, it wants more search and more knowledge about PSU Noise Filtering.
I am thinking to start from start, i.e from the input and some decoupling 1nF to various pins (according to evaluate schematics) having the output without any filtering (maybe only the electrolytic capacitor) and at the end to apply any changes at the output.
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Please, if someone has measured the values of smd capacitors C45, C40, C41 from the adapter board Ver. 3.2 or 3.3 it''ll be very appreciated. They are next to L2 & L3 5R6 inductors.
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About the maximum input voltage. I don't remember well but I think that the maximum of 400V is the adding of ac/dc components of singal and peak to peak not rms or average.
You are right!
I'm attaching the actual specs so this will be clear to all members. Don't want to see any more BOOMs! :-BROKE
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Please, if someone has measured the values of smd capacitors C45, C40, C41 from the adapter board Ver. 3.2 or 3.3 it''ll be very appreciated. They are next to L2 & L3 5R6 inductors.
Lemon, I tried to measure them, but they have to be unsoldered to get the correct values. So I'll have to be someone that have taken them off for experiments or repairs. The value I got is useless (.63 mF), but all three of them measure this same value in circuit because they are for all practical purposes in parallel.
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Tomorrow I could measure all them by separately. Well, not the most smaller, because I've lost it.
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Tomorrow I could measure all them by separately. Well, not the most smaller, because I've lost it.
That would be great! :-+ Thanks!
Any news on your EMI shielding project?
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Tomorrow I could measure all them by separately. Well, not the most smaller, because I've lost it.
Carrington for version 3.0 I have measured these little smd capacitors next to L2 (I unsoldered all of them), see at a quote of my previous message. I need the values for version 3.2/3.3 if it is possible.
TomC, thanks for the trial but I know there isn't way to measure right on pcb
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The pin7 & 8 are joined together. From this point Owon puts the D127 to gnd and through the L3 inductor with 3 caps parallel, C36/5uF, C45/12uF and C44/470uF.
...
Really, like as Tomc says, have any result from spray shielding?
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Today I wanted to see the signal across the current sense resistors (R5/R5A/R5B/R5C). This signal represents the current flowing through the primary winding when Q1 is turned ON. I spent considerable time trying to get a good capture, but the best I could get was a signal with an upward slant. The problem is again the fact that all primary signals are referenced to GND-A but the scope ground lead has to be on GND-C to avoid a short circuit. In the case of the current sense signal I had to set CH2 to 500mV/Div to get a reasonably viewable signal, but this makes the half wave rectified sine wave where it rides so large that it's impossible to pick a signal from the top of it. So I had to settle for a slanted signal. CH1 is connected to the anode of D8 to provide a reference of the cycle timing. I would have preferred to use Q1's drain for this, but when you connect even a short wire to this element it seems to emit radiation so strong that a low level signals such as the current sense signal is obliterated and replaced with an image of Q1's signal. This effect fooled me for a while but I couldn't believe what the signal was telling me, 11A flowing through Q1. So I kept digging until I realized the signal I was looking at wasn't real. The correct value as shown in the images is less than 1A.
#1 Shows 2 complete cycles of operation.
#2 Shows just the part of the cycle when Q1 is ON and the current is ramping up through the primary winding.
#3 Illustrates the reason why I had to settle for a current sense signal with an upward slant. The capture shows the half wave rectified sine wave with the current sense signal riding on it. The top of the half wave don't fit on the screen because of the CH2 V/Div setting, and as a result the only available current sense signals are on the slope up or down.
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Please, if someone has measured the values of smd capacitors C45, C40, C41 from the adapter board Ver. 3.2 or 3.3 it''ll be very appreciated. They are next to L2 & L3 5R6 inductors.
C45=C41=10uF
C40=100nF
Edit: This cap are from the adapter board Ver. 3.0.
About EMI: I don't know anything of the new boards, Aidetek is not responding to my messages, and my adapter board V3.0 is damaged. So I could not try anything.
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Carrington for version 3.0 I have measured these little smd capacitors next to L2 (I unsoldered all of them), see at a quote of my previous message. I need the values for version 3.2/3.3 if it is possible.
Oh sorry, I misunderstood you. I don't have the adapter board Ver. 3.2 or 3.3. The above values are for the 3.0 Ver.
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About EMI: I don't know anything of the new boards, Aidetek is not responding to my messages, and my adapter board V3.0 is damaged. So I could not try anything.
That's a bummer! :(
Can your V3.0 board be repaired, or is it a total loss?
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Please, if someone has measured the values of smd capacitors C45, C40, C41 from the adapter board Ver. 3.2 or 3.3 it''ll be very appreciated. They are next to L2 & L3 5R6 inductors.
C45=C41=10uF
C40=100nF
Edit: This cap are from the adapter board Ver. 3.0.
...
Carrington, I know that you have the version 3.0 for older your messages.
I would like to remember you that the sequence of capacitors at the output of AOZ1094(Version 3.0) is C36(smd), C45(smd), C44(electrolytic). To me this sequence is 5uF, 12uF, 470uF
The version 3.2 has different sequence like C45(smd), C44(electrolytic), C40(smd),C41(smd).
For the damage to yours adapter, if you need help I can help you to anything smd works on this (I have the appropriate equipment).
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Thank you very much to all.
The damaged part is the AZ1094 and inductor L3, and yes it can be repaired. But I'm waiting to see what happens with Aidetek, I will report to the forum.
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Today I looked at the voltages at the output of the feedback loop op-amps and at the COMP input of the R7731A. Since there are no significant load changes, these voltages should be pretty stable, so I measured them with a voltmeter. I also measured the 8.4V raw output because it is used as the bias voltage for the PH2 opto-coupler. The results were as follows:
PH2-2 PH2-4 8.4V raw (DC) 8.4Vraw (AC+DC)
------------ ------------ ------------------ ----------------------
100VAC 7.192V 1.620V 8.41V 8.356V
125VAC 7.192V 1.565V 8.41V 8.356V
140VAC 7.193V 1.535V 8.41V 8.356V
From the above I noticed that the only significant variations were at PH2-4, which is connected to the COMP input of the R7731A. This voltage controls the duty cycle, the lower the voltage, the lower the duty cycle. This is supposed to happen when the load is light and the output voltage rises. A lower duty cycles delivers less energy and brings the output voltage back to its nominal value. However, the COMP input is supposed to be controlled by the feedback loop op-amps via the opto-coupler. Neither one of the voltages driving the opto-coupler's LED is varying, so the COMP input shouldn't vary either, in theory. Of course, the input AC voltage is varying, and as we know from previous observations, this has caused other surprises, like causing the R7731's osc frequency to vary. So somehow, it seems to be causing this effect too.
Note that it's normal for the duty cycle to vary when the AC input voltage varies, but on current mode PWM controllers like the R7731A, this is accomplished via the effect of the current sense (CS) input. A higher AC input voltage causes more current to flow through the primary, which in turn causes the CS threshold to be reached sooner, and as a result causes Q1 to be turned off sooner.
Hoping that viewing the voltages with a scope rather than just the voltmeter may reveal something that I may have been missing, I decided to capture waveforms for the previously measured voltages. PH2-2 and the 8.4V raw output are on the secondary side and can be easily captured using GND-C as the reference. PH2-2 is a different story because it is on the primary side and is referenced to GND-A. I did try to capture it anyway, but the results are not trustworthy because you again have to use the math function and the signals are low level. So I'm not going to post that capture. The captures for PH2-2 were done using average mode to eliminate some of the random noise from the results, the 8.4V raw output was captured using sample mode. Again, I couldn't see any significant variations that could justify the voltage variations on PH2-4. So why the voltage at PH2-4 varies is still a mystery to me!
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Today I captured the flyback converter's output voltages. CH1 was connected to the 8.4V filtered output at J1-2. Ch2 was connected to the cathode of D9 which is used to power the green LED. Captures were taken at different mains voltages and different time division settings as indicated by the names of the attachments. No significant changes were observed as a result of varying the mains voltage.
This is the final set of measurements I had planned to do on the new Owon PSU board. This board is very similar to the previous version board for which I had previously posted a schematic. The latest version of this schematic can be found in the last attachment. The main difference between this schematic and the new PSU board is that Owon added many SMD bypass capacitors to reduce common mode noise. In addition, Owon rearranged and modified some circuit traces for the same purpose. However, all the component names and values are the same. The following are links to all the other posts that contain measurements and captures that I previously posted for this new Owon PSU.
https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/msg281838/#msg281838 (https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/msg281838/#msg281838)
https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/msg282227/#msg282227 (https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/msg282227/#msg282227)
https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/msg282577/#msg282577 (https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/msg282577/#msg282577)
https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/msg283026/#msg283026 (https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/msg283026/#msg283026)
https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/msg283664/#msg283664 (https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/msg283664/#msg283664)
https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/msg284227/#msg284227 (https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/msg284227/#msg284227)
https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/msg284737/#msg284737 (https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/msg284737/#msg284737)
My plan is to use these measurements and captures as a reference for comparison purposes. I'm hoping that this will be useful as I look at the equivalent components on my old PSU board. For this next step I will provide independent power and dummy loads for my old PSU so I can have easier access to its components. The final goal is to attempt to discover new ways of reducing common mode noise keeping in mind ease of implementation.
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TomC, keep good woriking about psu.
Your works is best and very soon you find new ways for better noise limited.
If you want to make some measurements for you, cause 230Vac, don't hesitate to ask me.
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Hi! I need a simple test of the scope, to see if it's just me or if this thing that's happening to me is normal.
So can anyone please set the scope to X-Y mode, invert one of the channels and report if that makes any difference to what's seen on screen in the X-Y mode? On my scope, it looks like channel inversion isn't working in X-Y mode and is fine in voltage-time mode.
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Hi! I need a simple test of the scope, to see if it's just me or if this thing that's happening to me is normal.
So can anyone please set the scope to X-Y mode, invert one of the channels and report if that makes any difference to what's seen on screen in the X-Y mode? On my scope, it looks like channel inversion isn't working in X-Y mode and is fine in voltage-time mode.
Andrejako, I've also had a lot of trouble and disappointment using the X-Y mode. I don't remember if channel inversion was one of them. I'm temporarily away from the lab right now, but I'll test this for you as soon as I get back. In the mean time, here is a link to a previous post where I describe some of the trouble I had with X-Y mode.
https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/msg246541/#msg246541 (https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/msg246541/#msg246541)
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Hi! I need a simple test of the scope, to see if it's just me or if this thing that's happening to me is normal.
So can anyone please set the scope to X-Y mode, invert one of the channels and report if that makes any difference to what's seen on screen in the X-Y mode? On my scope, it looks like channel inversion isn't working in X-Y mode and is fine in voltage-time mode.
AndrejaKo,
This seems to be another feature that don't work on X-Y mode. The following are some captures while using X-Y mode with my Semiconductor Curve Tracer. They include images for CH1/CH2 Inv OFF/ON.
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Thanks a lot! Too bad that inversion isn't working.
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...
There is coming some new, and I think, Owon have also learned something.
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(https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/?action=dlattach;attach=58902;image)
Just I saw the manual of Owon TDS Series (https://static.eleshop.nl/osc/downloads/Owon/Owon_TDS_USER_MANUAL_V1.0.pdf).
The philosophy and ergonomy of various menus is the same as SDS Series with some impovements and adding some more operations like the capability of touch screen and some others.
They have corrected all the minus of our fw, of course.
I don't know if they think to give us this fw but it'll be a shame if they don't.
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I've noticed few interesting things in the manual.
First, the scope doesn't need to warm up before self-calibration! I find that very interesting.
It's nice to see 50 ohm termination on the scope. No AC coupling with it though.
M knob was renamed to G knob. Hopefully that will stop some whining about the knob name.
It's nice to see that they added the ability to see the main waveform when zoomed in. I didn't really miss that, since I often it was easier for me to zoom in by hand instead of going to menu and select zoom option. I would have liked it if they added a special zoom/unzoom button on the control panel.
I'm a bit disappointed that there are no options to adjust the HF and LF trigger filters. They would have been useful to me few times.
I like the fact that they managed to add the trigger frequency to the bottom panel, so it doesn't take up space from waveform window.
Also persistence can now be adjusted precisely up to 10 seconds.
It's great that they added the option to change file format for saved images!!! Also it seems that Copy button can now be used to save to flash drive as well. Is that possible on SDS series? I've seen some images that don't have save menu visible, but I'm not sure if they were made from the scope ore remotely. Directories can now be navigated as well. Firmware can be upgraded from a flesh drive now as well.
Apparently, it's now possible to see both FFT and the signal at the same time, judging by screenshots in the manual.
Unfortunately, it seems that now all measurements take up space on the waveform window. On SDS it's possible to have up to 4 measurements without taking up any area on the waveform window.
As far as the sampling is concerned, it seems that there are two ADCs. Scope can run in one, two or four channel mode and sample rate is halved in four channel mode. I'm not sure if it can run with 3 channels and I'm not sure which channels are active in 2 channel mode.
Manual doesn't seem to mention the dreaded "user-friendly voice warning" which was much bashed in the TDS thread.
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I gave the manual a quick look and didn't see fine control for Vertical or Horizontal. Didn't see any differences on X-Y mode either. Can't really say I see a lot of improvement, just a few new features, like touch screen and 50 ohm input.
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For me the new Owon TDS is bad scope that I would never buy. Who needs touch screen or voice output (??) when you have no built-in signal generator, decoding, or digital channels... :-- :-- :--
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AndrejaKo, you read it with a more attention than me.
Sure the choice btw 50 Ohm or 1MOhm input is fine but the only the AC operation with 50 Ohm is strange.
As TomC said, the fine function seems to be missing.
I looked at the Vertical Operation and I don't find something about it.
Also, I think that the XY function is improved but I don't read it with attention something like a quick tour.
I think, this fw is basic to ours SDS fw. It is not an other fw, is the same with some improvements and some extra capabilities that TDS Series have.
Hydrawerk, personally I don't agree with your statement.
It remindes me the flame btw Rigol and other brands. For me the capability of touch screen is a usefull capability for some quickly operations or entry text/numeric on filenames areas.
I don't understand why this function must be only with built-in signal generator or decoding.
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TomC, what curve tracer do you have?
It looks interesting.
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AndrejaKo, you read it with a more attention than me.
Sure the choice btw 50 Ohm or 1MOhm input is fine but the only the AC operation with 50 Ohm is strange.
Actually, it has only DC operation in 50 ohm mode. I wrote that it has no AC mode.
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TomC, what curve tracer do you have?
It looks interesting.
Heathkit IT-3121. Bought it at eBay for $100 + $20 shipping
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Hydrawerk, personally I don't agree with your statement.
Maybe one day I will try out this Owon TDS and I will find the touch screen useful, who knows.
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I have almost 10mV improvement after some modifications to AOZ1094 circuit.
Here (https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/msg283454/#msg283454) is the measurements that I had before.
The Average noise (16) at Acq. Mode is 22mV with 100us and 14-16mV with 500us (before 30-34mV)
The Sample (normal) noise at Acq. Mode is 32-40mV with the most to be btw 34-38mV (before 40-52mV).
The Peak noise at Acq. Mode is 32-44mV with the most to be btw 34-40mV (before 40-52mV).
The last attachment photo is what I do to adapter board.
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I have almost 10mV improvement after some modifications to AOZ1094 circuit.
Here (https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/msg283454/#msg283454) is the measurements that I had before.
The Average noise (16) at Acq. Mode is 22mV with 100us and 14-16mV with 500us (before 30-34mV)
The Sample (normal) noise at Acq. Mode is 32-40mV with the most to be btw 34-38mV (before 40-52mV).
The Peak noise at Acq. Mode is 32-44mV with the most to be btw 34-40mV (before 40-52mV).
The last attachment photo is what I do to adapter board.
That's excellent! :-+
With that low average noise you shouldn't have any problems triggering on low level signals!
Recently I was checking the GND noise on my scope with the ferrites on the probes which I now have permanently installed, on sample mode, the noise is no longer strong enough to allow me to trigger the scope (normal trigger) anymore.
I will soon start testing my old PSU, I've been preparing the test bed, and that includes better means of testing at mains voltages from 100-250VAC. So I'm in the process of redesigning my variable AC supply to include that facility.
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Hello everyone! Someone tell me - is there a new firmware? (2.8.3 above).... the official site problem ... :-//
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No there is no any problem at their site.
They changed the site, that operate different than previous site.
Go to the Product Service of the menu and choice Software Upgrading from the drop down menu.
Fill you serial number to the Input Sequence Number area without the last 3 digits of your sn.
Example: if you have sn with SDS71021211xxx fill with SDS71021211 and click to GO.
For mine sn the fw is SDS7102UP3.3 (they haven't release new fw from April).
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Got it. Thank you.
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I have almost 10mV improvement after some modifications to AOZ1094 circuit.
Here (https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/msg283454/#msg283454) is the measurements that I had before.
The Average noise (16) at Acq. Mode is 22mV with 100us and 14-16mV with 500us (before 30-34mV)
The Sample (normal) noise at Acq. Mode is 32-40mV with the most to be btw 34-38mV (before 40-52mV).
The Peak noise at Acq. Mode is 32-44mV with the most to be btw 34-40mV (before 40-52mV).
The last attachment photo is what I do to adapter board.
That's excellent! :-+
With that low average noise you shouldn't have any problems triggering on low level signals!
Recently I was checking the GND noise on my scope with the ferrites on the probes which I now have permanently installed, on sample mode, the noise is no longer strong enough to allow me to trigger the scope (normal trigger) anymore.
I will soon start testing my old PSU, I've been preparing the test bed, and that includes better means of testing at mains voltages from 100-250VAC. So I'm in the process of redesigning my variable AC supply to include that facility.
The one day I was happy the other day was unhappy!
Now, I have problem with the measurement by long gnd lead.
Look at the attachment captures.
With the short gnd clip everything is OK but with the long gnd lead everything is bad.
Now I must looking what went wrong...
The signal is clearly from noise but has oscillation.
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I have almost 10mV improvement after some modifications to AOZ1094 circuit.
Here (https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/msg283454/#msg283454) is the measurements that I had before.
The Average noise (16) at Acq. Mode is 22mV with 100us and 14-16mV with 500us (before 30-34mV)
The Sample (normal) noise at Acq. Mode is 32-40mV with the most to be btw 34-38mV (before 40-52mV).
The Peak noise at Acq. Mode is 32-44mV with the most to be btw 34-40mV (before 40-52mV).
The last attachment photo is what I do to adapter board.
That's excellent! :-+
With that low average noise you shouldn't have any problems triggering on low level signals!
Recently I was checking the GND noise on my scope with the ferrites on the probes which I now have permanently installed, on sample mode, the noise is no longer strong enough to allow me to trigger the scope (normal trigger) anymore.
I will soon start testing my old PSU, I've been preparing the test bed, and that includes better means of testing at mains voltages from 100-250VAC. So I'm in the process of redesigning my variable AC supply to include that facility.
The one day I was happy the other day was unhappy!
Now, I have problem with the measurement by long gnd lead.
Look at the attachment captures.
With the short gnd clip everything is OK but with the long gnd lead everything is bad.
Now I must looking what went wrong...
The signal is clearly from noise but has oscillation.
Later today I'll do the same test and see what my results are for the same frequency and signal amplitude. I'll try with the probe ferrites on and off for better comparison. What I think I see on your captures is that predominant 100MHz GND noise riding on the 50mV 10MHz signal. Is that what the FFT is telling you?
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TomC, at page 107 you have done the same test and you were OK.
At the same time I have done the same tests until 10MHz (I have 10MHz signal generator) and I was OK, too.
I changed the L2, I removed the second L and bridged this, I removed the smd capacitor next to D127, I removed the zero resistor btw the two ground planes and bridge this...but nothing! The same issue is continues...
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TomC, at page 107 you have done the same test and you were OK.
At the same time I have done the same tests until 10MHz (I have 10MHz signal generator) and I was OK, too.
I changed the L2, I removed the second L and bridged this, I removed the smd capacitor next to D127, I removed the zero resistor btw the two ground planes and bridge this...but nothing! The same issue is continues...
Thanks for reminding me!
So many posts on noise, I didn't remember I had already tried this particular test.
Was anything different when you had good results, like the place you did the test, or where the generator was plugged in? It is always possible that the common mode noise is coming from a source other than the scope, even in that case the short ground lead will prevent it from being displayed because it will prevent it from changing to differential mode noise.
Let me know if there is anything I can do to help!
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TomC, at page 107 you have done the same test and you were OK.
At the same time I have done the same tests until 10MHz (I have 10MHz signal generator) and I was OK, too.
I changed the L2, I removed the second L and bridged this, I removed the smd capacitor next to D127, I removed the zero resistor btw the two ground planes and bridge this...but nothing! The same issue is continues...
Lemon,
I looked some more at the images from your test and I have a suspicion that you may want to check. Looking at the signal riding on top of your 50mV 10MHz signal, I'm pretty sure this is a single frequency of about 100MHz. I suspect that this is visible, partly due to a strong 10th harmonic from the 10MHz base frequency that is being produced by your generator, and partly due to the effect of the resonant circuit formed by the long ground lead and the input capacitance of the probe. On previous experiments I've conducted (see post #1117 via the link below), I've found that this resonant frequency is in the vicinity of 100MHz.
https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/msg233851/#msg233851 (https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/msg233851/#msg233851)
If this is the case, the problem should considerably diminish as you change the generator's frequency. For example, with the generator set to 8MHz the harmonics closest to 100MHz would be 96MHz and 104MHz.
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Lemon,
Here are some captures at the frequency that looks worst on my scope, on the first two there are no ferrites on the probes and the probes are hanging down. The third capture is with the same settings but I have re-installed the ferrites on the probes. I don't think these signals are that different from what you got. I still suspect that part of the problem is the resonance of the ground lead and the probe's input capacitance. I don't remember for sure, but is possible that when I did the tests on page 107 I had already permanently installed ferrites on my probes. I tried to get those results again without the ferrites by positioning the probes differently and couldn't in the frequencies around 10MHz. When I get to around 20MHz the 100MHz ringing mostly disappears. It is worst at the frequency of the attached images.
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TomC, your suspect that part of the problem is the resonance of the ground lead and the probe's input capacitance, probably is true but I have the suspection that to me there is adding problem.\
I add some ferrites to the probe, nothing the same.
I change the generator frequency from 4-10.9MHz nothing the same.
From what I see there is a ringing to all frequencies.
Look at the attachments. At the first I connected the probe to signal generator output with ac mains off....what is this?
If I turn the switch on of the signal generator I have always the same ringing (see at the 4.1MHz), if I lower the amplitude of signal generator until very low the signal will be the same like complete closed!
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TomC, your suspect that part of the problem is the resonance of the ground lead and the probe's input capacitance, probably is true but I have the suspection that to me there is adding problem.\
I add some ferrites to the probe, nothing the same.
I change the generator frequency from 4-10.9MHz nothing the same.
From what I see there is a ringing to all frequencies.
Look at the attachments. At the first I connected the probe to signal generator output with ac mains off....what is this?
If I turn the switch on of the signal generator I have always the same ringing (see at the 4.1MHz), if I lower the amplitude of signal generator until very low the signal will be the same like complete closed!
I think that first capture the generator is acting as an antenna because is off. It looks like a lot of radiated power coming from somewhere, and the large ringing is close to 10MHz, the small still 100MHz.
I also get ringing in frequencies like 4MHz without ferrites on the probes, however, I still can trigger on the low level signals, anything around 40mV or higher I can trigger OK even if there is ringing. With the ferrites on the probes most of this ringing disappears. I use two ferrites on each probe, the type that you normally use for power cables, one near the BNC, and the other near the probe. The probe cable is looped once around each of these ferrites for double the inductance. Is that the way you setup your ferrites? I would have expected that to help your ringing, because it looks so similar to mine.
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I use two ferrites on each probe, the type that you normally use for power cables, one near the BNC, and the other near the probe. The probe cable is looped once around each of these ferrites for double the inductance
TomC, No I used two ferrites without any looped to cable. I'll do a test like this and reply about this.
Attention the following information is from Adapter Ver. 3.0
I upload some measurements captures from the AOZ circuits as I modificated this at the last.
Unfortunately the initial referenced measurements (https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/msg283454/#msg283454) had limited BW (20MHz) and I can't to compare with these that is full BW.
But, there is one measurement with a full BW that with D127 180°turn modification (this method decrease almost 40% the noise). This measurement has taken at the output of 5.5V after the C45 capacitor. Upper is waveform from 5.5V output, bottom is gnd-noise.
(https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/?action=dlattach;attach=59092;image)
The 5.52V Output.png is the measurement at the same position as before but now is at the last decoupling capacitor after the second 5R6 inductor. There is another timing than before, 200ns vs 100us but the level of noise is significantly lower than previous measurement (28mVp-p with 10X attenuation = 2.8mVp-p with 1X). The previous measurement was 74mVp-p (10X).
I am very sure that if I capture with the 100us the noise will be bigger but sure very lower than 74mVp-p.
The second yellow waveform is the gnd-noise capture.
The AOZ1094.png is the capture with the probe tip over the chip. As you see there are some signs that related to some spikes at the yellow waveform (gnd-noise). Sure there is need to investigate that but I don't know if that is normal or my AOZ is defected from many soldering-desoldering that I make to all this area of circuits.
The D127.png and L3.png is the captures with the probe over of them. They have identical pattern. At this point, I had some measurements with decoupling capacitor or no at the cathode of diode. The decoupling capacitor is minimize at little the ringing of pulse and for that reason I applied it.
At the end there is no any measurement on the last 5R6 Coiltronics inductor. It is shielded and you can't to record any waveform over this.
I think that the modification of this area has reached its limits given the existing circuit topology. There is one option, yet. The replacement of second inductor by ferrite with a very low DC resistance.
Now I'll focus to the crappy LED Circuit Backlight.
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Lemon,
Here are some captures at the frequency that looks worst on my scope, on the first two there are no ferrites on the probes and the probes are hanging down. The third capture is with the same settings but I have re-installed the ferrites on the probes. I don't think these signals are that different from what you got. I still suspect that part of the problem is the resonance of the ground lead and the probe's input capacitance. I don't remember for sure, but is possible that when I did the tests on page 107 I had already permanently installed ferrites on my probes. I tried to get those results again without the ferrites by positioning the probes differently and couldn't in the frequencies around 10MHz. When I get to around 20MHz the 100MHz ringing mostly disappears. It is worst at the frequency of the attached images.
I done one measurement of 10MHz at 40mV output. Two large ferrites with each of them with one looped cable inside.
Yes there is an improvement but without right triggering. The reason of this is that I have removed all the mods to the Led Back-light Circuit and for this time the gnd-noise has increased.
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I done one measurement of 10MHz at 40mV output. Two large ferrites with each of them with one looped cable inside.
Yes there is an improvement but without right triggering. The reason of this is that I have removed all the mods to the Led Back-light Circuit and for this time the gnd-noise has increased.
Nice! :-+
I think it will get even better when you put the mods back in.
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Some Observations on LCD Backlight Circuit about (Adapter Version 3.0).
The adapter version 3.0 has an unique design. The output of 5.5V divided at two parts. The first one (right side) supplies the main board, the second one (left side) supplies the LCD Backlight Circuit (and go on...).
The unique design divides not at the end of the right side after the decoupling capacitors but direct to the L3 output.
Look at the photo "Adapter mods2".
If you measure at Point A that is the 5.5V output to mainboard the result will be the photo "5_6 Output to Mainboard".
If you measure at Point B that is the output of L3 the result will be the photo "L3".
If you measure before L2 (input) the result will be the photo "Input before L2", at the end the same measure after the L2 inductor is the photo "Input after L2".
What crappy design is this?
The input ripple to L2 is very big and of course this effect to the gnd-noise.
If you see the output waveform, will be the photo "Output C35". This measure is done at the ends of C35. My multimeter displays at this point 8.765 Vrms (I had 0% the backlight position)
At the next stage I am going to investigate more this area of circuit and I'll try to eliminate this behaviour.
Here is some measurements captures with the probe over the components without gnd connected.
D1X = over the diode
IC = over the IC S126k
L2 = over the inductor L2
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I done one measurement of 10MHz at 40mV output. Two large ferrites with each of them with one looped cable inside.
Yes there is an improvement but without right triggering. The reason of this is that I have removed all the mods to the Led Back-light Circuit and for this time the gnd-noise has increased.
Nice! :-+
I think it will get even better when you put the mods back in.
At the end of this investigation...I''ll come back with this. :-+
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Oh, I am not very familiar with these Owon bugs, but one thing is clear. I am never gonna buy any Owon scope. Even their TDS series is crap when compared to GW Instek, Rigol, Siglent or Agilent. (Unless you really need a touch screen. ;D ;D )
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Hydrawerk, "never say never".
This conversation about improvement of adapter circuit takes place only for older adapter versions.
For us to participate to this, is something like exercise to play with this circuit. The osciloscope is fine for measurements, there is no any problem about this.
Today this issue there is no exist and all the Owon SDS oscilloscopes are gnd noise free.
Owon starts (in some cases) to cover by warranty some customers via the dealer who sold the problematic oscilloscope. Perhaps, Owon starts to learn how to support the customer after sales.
We don't know how "crappy" is the TDS Series, there is no any review about this only photos and some technical characteristics.
But, the things is not paradise to other bigger companies. For example, the Rigol DP-832 is the recent case of problematic unit (I am owner of this) with problems that is more major from initial gnd-noise of Owon.
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We don't know how "crappy" is the TDS Series, there is no any review about this only photos and some technical characteristics.
Well, according to the manual, the TDS has:
-no digital channels
-no intensity grading
-no signal generator
-no fine vertical controls
-no serial decoding
-no USB port on front panel
Well, we needn't call this TDS scope crappy, but it is no competitor for Rigol or GW Instek
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Hydrawerk,
I'm just trying to understand your reasoning! :-//
Do you own a scope? If so, how did you decide it was the right one for you?
From your post, I get the impression that you value a number of unrelated features. Do you actually have applications in your line of work for all of them?
For my needs, the only feature on your list that I wish my SDS scope had is the fine control.
However, if you do actually need all these features and are willing to pay for them, then you are right!
The SDS and TDS scopes shouldn't be on your list.
However, keep in mind that different users have different needs, and a list of features is just that, a list!
So when you say that the SDS and TDS are no competitors for Rigol or GW Instek, I hope you mean that this is true as far as your own personal needs are concerned, and are not presuming that this should apply to all other users.
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I agree totaly with the TomC.
Additional this thread is for SDS Series and not for TDS. TDS Series have their own thread and is better any talk to be there.
TDS Series aren't available yet and we don't know which is their target group.
Personaly I haven't any information about this.
Personaly, I haven't any love with a specific trade.
For me and my economical situation the vfm is critical factor to buy a device.
SDS Series now they are good oscilloscopes for the price that they have.
They have some basic fw and some functions are missing like fine control tuning but at least these fw haven't bugs.
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Oh, I am not very familiar with these Owon bugs, but one thing is clear. I am never gonna buy any Owon scope. Even their TDS series is crap when compared to GW Instek, Rigol, Siglent or Agilent. (Unless you really need a touch screen. ;D ;D )
Why I feel you love to troll around ? Like jumping in a thread like this where owners are discussing "specific" scope model and bashing it like there is no tomorrow ? And I noticed you did that at Rigol thread too. And its funny the brand GW Instek always pop out at this typical post of yours. :-DD
Its become tiring to read it too often, and you should know it better post like this is not going to be welcomed.
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Well, the talk is LED Backlight Circuit about (Adapter Version 3.0).
The main dc-dc convertor marks 5126x and it is a G5126 High Efficiency, Constant Current, Boost DC/DC White-LEDs Drive of Global Mixed-mode Technology Inc. (Taiwan Company).
You can find the pdf here (http://www.google.gr/url?sa=t&rct=j&q=&esrc=s&source=web&cd=2&cad=rja&ved=0CDgQFjAB&url=http%3A%2F%2Fwww.gmt.com.tw%2Fproduct%2Fdatasheet%2FEDS-5126.pdf&ei=o6swUrTFFcrKtAatsIC4BA&usg=AFQjCNFJCMvyN_MG6gKWqGE9MxJuU-hGoQ&bvm=bv.52109249,d.Yms.)
At the attachment files there are one photo of this pcb area and the diagram from datasheet of this IC.
Owon seems to follow the directions of manufacturer, there are two decoupling capacitors C40, C41 at the input supply , there is an inductor of 10uH between input and LX and so on.
The only that missing is the 1uF output capacitor that there is a position for that but it is empty (C35).
Unfortunately, there isn't any significant improvement of this circuit and it has problematic supply at the input because it is sharing with other sources.
The input voltage of IC measured at 5.54Vrms when the datasheet refers range of power supply 2.7-5.5V. A little bit critical to my opinion.
The output voltage of this IC measured at position of C35 at 8.765Vrms with the Backlight to 0%.
At my next message, I'll present some small improvements to this area.
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Owon seems to follow the directions of manufacturer, there are two decoupling capacitors C40, C41 at the input supply , there is an inductor of 10uH between input and LX and so on.
The only that missing is the 1uF output capacitor that there is a position for that but it is empty The output voltage of this IC measured at position of C35 at 8.765Vrms with the Backlight to 0%.
This datasheet circuit is ok only in principle. But not in practice if look how it need do in real life.
About voltage in position of "missing" C35 (I recommend install there some small good ceramic capacitor instead of electrolytic what have nothing to do there - exept if want some decorative reasons). (in real it is not missing but it is in totally wrong place after long trace - if it is there near TFT Led connector.) Voltage is what it is. Important is current and it is current controlled. In 100% position current is around 200mA as described in Cimei-Innolux (TFT) datasheet. What voltage it give over series connected leds (voltage may vary dependent of led manufacture lot and temperature etc) is not very important. I have measured some amount different voltages in different individual scopes. (mostly some amount higher if I remember right)
In 2011 this circuit was this (and note: backlight brightness control range was more wide)
(http://i969.photobucket.com/albums/ae171/Xie_07/TFT_LEDdriver1.jpg)
This circuit need good bypass capacitor in its input and its output. (there is not)
In some versions output capacitor is also behind long PCB trace and this is totally wrong and also as in many cases, there have been even crap electrolytic only alone, and this is just like nothing with these risetimes and frequencies. Just becouse they follow only this kind of datasheed principled schematics. (and same problem in some other circuits)
In this kind of SMPS, both current loops need be low inductance and if want avoid common mode noise in GND these current loops over GND need isolate from common GND area using "single point" connection so that this RF current do not fllood around ground. This PCB "topology" is terrible if think EMI. They have tried break all possible rules what can break if want design low EMI circuit.
Brightness control is different (freq/duty)
Input and output need bypass very tightly and as close as possible.
Today current sense resistor (R17 in this image) is typically 1R0.
22 Feb 2013, 18:54 Post subject:
--------------------------------------------------------------------------------
This old information is obsolete for 2012 and 2013 versions
2011 end, 2012 whole adapter board have been under development and it have changed many times! Sometimes less, sometimes radically.
Also in adapter board TFT backlight LED control have changed (many times) and freq are different. Also components are different. But still principle is same.
Last versions this circuit produce lot of noise and it need also modify on the aadapter board for less noise. (+ some other modifications for reducing GND noise.)
Backligt LED's current is important parameter and it need follow Innolux datasheet!
Also note, control IC have changed and it is not anymore 5126W.
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Why I feel you love to troll around ? Like jumping in a thread like this where owners are discussing "specific" scope model and bashing it like there is no tomorrow ? And I noticed you did that at Rigol thread too.
Well, DS2000 is a good bang per buck, there is no doubt.
And its funny the brand GW Instek always pop out at this typical post of yours. :-DD
Just because the GDS-2000A is quite nice scope with decent quality.
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rf-loop very interesting information.
Yes, we are familiar with the changes that have done to Version 3.2 or 3.3, just this is like exercise to this circuit and how we can to improve with its limit.
I believe that I have followed your thought with these mods.
There are decoupling capacitors at the input and the output.
Here the tests before and after mods. The waveforms captures are with the tip of probe over the component without gnd connected anywhere.
All the spikes has gone. It is very interesting how eliminated all the spikes at the output.
Attachment files
mods.png = the mods on this area
L2.png = measurement over the L2 inductor
D12.png = measurement over the diode
IC.png= measurement over the EDS-5126
Output.png = measurement at the C35 position
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Hydrawerk,
I'm just trying to understand your reasoning! :-//
Do you own a scope? If so, how did you decide it was the right one for you?
Yes, a DSOX2002A. https://www.eevblog.com/forum/reviews/my-new-toy-%29-agilent-dsox2002a-sex-on-a-stick (https://www.eevblog.com/forum/reviews/my-new-toy-%29-agilent-dsox2002a-sex-on-a-stick)!/msg216361/#msg216361
If so, how did you decide it was the right one for you?
It is rather a long story... My friend had a bad experience with his Rigol. https://www.youtube.com/user/BigOne332137/search?query=rigol (https://www.youtube.com/user/BigOne332137/search?query=rigol) I wanted a scope with a free waveform generator. I knew many Agilent scopes from my university. They were easy to operate and very responsive. I was considering even the GDS-2000A, but I found out, that its Trig Out is weird.
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Hydrawerk,
I'm just trying to understand your reasoning! :-//
Do you own a scope? If so, how did you decide it was the right one for you?
Yes, a DSOX2002A. https://www.eevblog.com/forum/reviews/my-new-toy-%29-agilent-dsox2002a-sex-on-a-stick (https://www.eevblog.com/forum/reviews/my-new-toy-%29-agilent-dsox2002a-sex-on-a-stick)!/msg216361/#msg216361
If so, how did you decide it was the right one for you?
It is rather a long story... My friend had a bad experience with his Rigol. https://www.youtube.com/user/BigOne332137/search?query=rigol (https://www.youtube.com/user/BigOne332137/search?query=rigol) I wanted a scope with a free waveform generator. I knew many Agilent scopes from my university. They were easy to operate and very responsive. I was considering even the GDS-2000A, but I found out, that its Trig Out is weird.
Nice scope! Nice features! :-+
However, the price tag of around US $1200 for a 70MHz scope would have eliminated it as a choice for my needs/budget. You see, I already own two 60MHz CROs, so for my first DSO, I valued a functional 200MHz bandwidth over a built in function generator. And with a price tag of US $430 for the Owon SDS, there would have been no contest between these two choices.
Good luck with your new scope, I hope you enjoy it! :)
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rf-loop very interesting information.
Yes, we are familiar with the changes that have done to Version 3.2 or 3.3, just this is like exercise to this circuit and how we can to improve with its limit.
I believe that I have followed your thought with these mods.
There are decoupling capacitors at the input and the output.
Here the tests before and after mods. The waveforms captures are with the tip of probe over the component without gnd connected anywhere.
All the spikes has gone. It is very interesting how eliminated all the spikes at the output.
Attachment files
mods.png = the mods on this area
L2.png = measurement over the L2 inductor
D12.png = measurement over the diode
IC.png= measurement over the EDS-5126
Output.png = measurement at the C35 position
Those are amazing results! :-+
The improvement on the output waveform is incredible, great job! :-+
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In some versions output capacitor is also behind long PCB trace and this is totally wrong and also as in many cases, there have been even crap electrolytic only alone, and this is just like nothing with these risetimes and frequencies. Just becouse they follow only this kind of datasheed principled schematics. (and same problem in some other circuits)
In this kind of SMPS, both current loops need be low inductance and if want avoid common mode noise in GND these current loops over GND need isolate from common GND area using "single point" connection so that this RF current do not fllood around ground. This PCB "topology" is terrible if think EMI. They have tried break all possible rules what can break if want design low EMI circuit.
I feel the same way,
A capacitor at the end of a long trace may help the output waveform, but where high frequencies or fast changing signals are involved, I don't think it will do anything to stop the energy radiated or capacitively coupled to adjacent circuits/traces by the long trace. You may not see a problem at the output, but the common mode noise coupled to other circuits/traces via the long trace will still be there.
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Here the tests before and after mods. The waveforms captures are with the tip of probe over the component without gnd connected anywhere.
Good result with this mod on this board version.
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More improvements. Now most of the noise comes from the local FM station 106.5MHz (previously I could not see this, because the SDS noise covered it). I have to paint the wall with conductive paint too... :-DD
Owon, takes note! :-/O
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This circuit need good bypass capacitor in its input and its output. (there is not)
In some versions output capacitor is also behind long PCB trace and this is totally wrong and also as in many cases, there have been even crap electrolytic only alone, and this is just like nothing with these risetimes and frequencies. Just becouse they follow only this kind of datasheed principled schematics. (and same problem in some other circuits)
In this kind of SMPS, both current loops need be low inductance and if want avoid common mode noise in GND these current loops over GND need isolate from common GND area using "single point" connection so that this RF current do not fllood around ground. This PCB "topology" is terrible if think EMI. They have tried break all possible rules what can break if want design low EMI circuit.
https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/msg263208/#msg263208 (https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/msg263208/#msg263208)
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Thanks guys for encourage to my trials.
Carrington, your news is marvelous.
I am looking here to find Kontakt 35 or similar product.
When you have time, don't forget to upload the measurements after the apply of shielding.
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Hi guys! I have a bot of time now so I want to try few more experiments.
@Carrington How much spray did you use to cover the inside of the scope? I'm thinking of getting Kontakt Chemie EMI 35 and apply it to the insides. My situation is currently reverse of your own. My scope jams all FM stations from 96 MHz to 97 MHz when on. Also any chance of screenshots of noise after the spraying?
@lemon I'll try your adapter board mods and report back the results.
If I remember correctly, there was one theory that mentioned noise on the sense pin of MC34063 is the reason for duty cycle change. If I understand how this works correctly, decreasing resistors on the pin should increase noise immunity, right? My PSU has a 9.07 kiloohm resistor marked R37 from the pin to the ground and 1.794 kiloohm resistor marked R40 from -7.6 V to sense pin. This should give nominal voltage of -7.569 V and current through the resistors of around 700 microamperes, if I'm right. I'll try with combination of 1.1k and 5.6k and see how that goes.
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More improvements. Now most of the noise comes from the local FM station 106.5MHz (previously I could not see this, because the SDS noise covered it). I have to paint the wall with conductive paint too... :-DD
Owon, takes note! :-/O
Nice paint job! :-+
Did you fix your adapter board? Or did you get new boards from Aidatek?
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If I remember correctly, there was one theory that mentioned noise on the sense pin of MC34063 is the reason for duty cycle change. If I understand how this works correctly, decreasing resistors on the pin should increase noise immunity, right? My PSU has a 9.07 kiloohm resistor from the pin to the ground and 1.794 kiloohm resistor from -7.6 V to sense pin. This should give nominal voltage of -7.569 V and current through the resistors of around 700 microamperes, if I'm right. I'll try with combination of 1.1k and 5.6k and see how that goes.
Yes, that's a possibility. Just looking at the values you propose it seems that you are keeping the same ratio, which is what is needed. Let us know what happened once you try it!
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TomC, if you see at the Carrington's attachment photo the two boards are new versions (and the show is that the new PSU board haven't any mark again!)
AndrejaKo, I'll waiting for your results and observations, start at the first with the LED Backlight mods.
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TomC, if you see at the Carrington's attachment photo the two boards are new versions (and the show is that the new PSU board haven't any mark again!)
AndrejaKo, I'll waiting for your results and observations, start at the first with the LED Backlight mods.
Good eyes!
I missed that on my first view.
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Thanks guys for encourage to my trials.
Carrington, your news is marvelous.
I am looking here to find Kontakt 35 or similar product.
When you have time, don't forget to upload the measurements after the apply of shielding.
With shielding.
Edit:
- On DSC04301.JPG probe X10, i.e. real Vpp noise is 2.8mV. Because this noise come from the big gnd loop.
- Note the peak over 106.5MHz, i.e. internal FM receiver Osc. to get 10.75MHz IF.
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@Carrington How much spray did you use to cover the inside of the scope?
You need a full pot of EMV35. I also use adhesive paper tape in big holes, you need to fill all button holes with plasticine without dirtying the rest around.
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Nice paint job! :-+
Thanks, is easy to do.
Did you fix your adapter board? Or did you get new boards from Aidatek?
Yes, I get the new boards from Aidetek, but this was not easy. Owon don't want selling directly to me the adapter board. Why? I don't know.
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I have pending shield the screen, the necessary material to do this is expensive and hard to find.
Is important find the best point to joint the metal Z-shaped plane with the housing shield.
Without the shield and using the short gnd probe cable the noise was around 50 mV.
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Your final results after the changing of two boards and your works with the spay shielding is marvelous.
Your gnd-noise level of 28mVp-p isn't with a loop cycle of probe cable but with the straight. If you measure it again like as we have said, I am very sure that you'll have under 20mVp-p.
Your test with FFT and the small radio was "all the money"! :)
The next one for all our forum company is to make a good fw for this oscilloscope and change the label as "AWLtB" (As We Like to Be)" :-DD
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Your final results after the changing of two boards and your works with the spay shielding is marvelous.
Your gnd-noise level of 28mVp-p isn't with a loop cycle of probe cable but with the straight. If you measure it again like as we have said, I am very sure that you'll have under 20mVp-p.
Your test with FFT and the small radio was "all the money"! :)
The next one for all our forum company is to make a good fw for this oscilloscope and change the label as "AWLtB" (As We Like to Be)" :-DD
Well, now there is not much difference.
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- Note the peak over 106.5MHz, i.e. internal FM receiver Osc. to get 10.75MHz IF.
Great results! Congratulations! :-+
The effect of the radio on the FFT is interesting. With the shielding on the cabinet I assume the radiation is coming through the probe cable. Did you try moving the radio further away to see when the effect decreased?
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Well, now there is not much difference.
Looks like 5mVpp better!
When the GND noise is that low a few millivolts less are hard to achieve. With the ferrites on my probes my noise is still a little higher than that. However, the position of the probe cables in respect to the scope don't have much of an effect.
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The effect of the radio on the FFT is interesting. With the shielding on the cabinet I assume the radiation is coming through the probe cable. Did you try moving the radio further away to see when the effect decreased?
Obviously that's what happens.
- "Radio Osc" -> 106.5MHz + 10.75MHz. Away from gnd loop ~1cm.
- "Cadena Ser" -> 106.5MHz FM. Away from gnd loop ~1Km.
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Great work Carrington! I agree with lemon, the demonstration with FFT and radio is really great.
Anyway, I did the backlight mod and it got rid of the peaks in its area. Results are same as lemon's.
I've also changed resistors for the comparator pin of the MC 34063A, but that gave no improvement to the duty cycle issue. It' still changing all the time. I took some time and probed around the PSU and I've noticed that the whole +8.4 V rail is contaminated with noise. I'm not sure from where it could be coming. It doesn't look to me as if the main source could be coming from the MC. I've probed the comparator pin on MC and results are attached. I also removed the capacitors that were going from the resistors to ground at the sense pin. This made the noise a bit clearer to see.
Basically the noise is cyclic and here's how cycle looks like: First, there's the quiet period seen on the left side of the picture. Here we have the usual switching noise from the MC. Then near the trigger point, comes the first wave of the noise. Then there's a short quiet period (10 microseconds here). After it comes the second noise noise wave. After comes the long quiet period. I'm also not sure how to actually trigger on this event. I captured it by repeatedly pressing the single button.
The probing was done with the oscilloscope running on battery.
If I understand how this PSU works, when on battery, everything south of D8 should be off. This means that the only two ICs running are the MC34063A and the LM324. The LM shouldn't do anything smart when the PSU is running on the battery. My idea is to try replacing it and see if anything happens. I'll also see if I can re-trace the board and make a schematic of the area near the LM. In my version of the PSU, all four op-amps are in use.
If this doesn't help, I'll see if I can run the PSU without both the MC and the LM.
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Great work Carrington! I agree with lemon, the demonstration with FFT and radio is really great.
Anyway, I did the backlight mod and it got rid of the peaks in its area. Results are same as lemon's.
I've also changed resistors for the comparator pin of the MC 34063A, but that gave no improvement to the duty cycle issue. It' still changing all the time. I took some time and probed around the PSU and I've noticed that the whole +8.4 V rail is contaminated with noise. I'm not sure from where it could be coming. It doesn't look to me as if the main source could be coming from the MC. I've probed the comparator pin on MC and results are attached. I also removed the capacitors that were going from the resistors to ground at the sense pin. This made the noise a bit clearer to see.
Basically the noise is cyclic and here's how cycle looks like: First, there's the quiet period seen on the left side of the picture. Here we have the usual switching noise from the MC. Then near the trigger point, comes the first wave of the noise. Then there's a short quiet period (10 microseconds here). After it comes the second noise noise wave. After comes the long quiet period. I'm also not sure how to actually trigger on this event. I captured it by repeatedly pressing the single button.
The probing was done with the oscilloscope running on battery.
If I understand how this PSU works, when on battery, everything south of D8 should be off. This means that the only two ICs running are the MC34063A and the LM324. The LM shouldn't do anything smart when the PSU is running on the battery. My idea is to try replacing it and see if anything happens. I'll also see if I can re-trace the board and make a schematic of the area near the LM. In my version of the PSU, all four op-amps are in use.
If this doesn't help, I'll see if I can run the PSU without both the MC and the LM.
As far as I know, you are right in all the assumptions about how the circuit works. I assume you are doing all testing in the no-electronics room, so we can assume there is no external interference. I doubt that the LM can cause any trouble here, but you can probe the output pins to see if there are any oscillations. The noise in the 8.4V rail may be causing the MC to misbehave, there are not very many other suspects, since I think you have replaced just about every component in that area. There may be something wrong with the battery itself, or its protection circuits. Have you tried a ferrite on the battery cable to see if this reduces the noise on the 8.4V rail?
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The effect of the radio on the FFT is interesting. With the shielding on the cabinet I assume the radiation is coming through the probe cable. Did you try moving the radio further away to see when the effect decreased?
Obviously that's what happens.
- "Radio Osc" -> 106.5MHz + 10.75MHz. Away from gnd loop ~1cm.
- "Cadena Ser" -> 106.5MHz FM. Away from gnd loop ~1Km.
Thanks for the info!
That FM station is really close to you!
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As far as I know, you are right in all the assumptions about how the circuit works. I assume you are doing all testing in the no-electronics room, so we can assume there is no external interference. I doubt that the LM can cause any trouble here, but you can probe the output pins to see if there are any oscillations. The noise in the 8.4V rail may be causing the MC to misbehave, there are not very many other suspects, since I think you have replaced just about every component in that area. There may be something wrong with the battery itself, or its protection circuits. Have you tried a ferrite on the battery cable to see if this reduces the noise on the 8.4V rail?
I added a ferrite to the battery lead, but it did not help. I also removed the PSU from the scope and did some measurements with it connected only by cables. The Z-plate is still full of noise spikes and I think that the noise could be coming from the Z-plate to the PSU. The type of noise I previously described to me seems a bit stronger on the Z-plate than on the PSU ground. That should be expected, since I have ferrite on PSU to adapter board cable.
A few things to try out:
I have a linear PSU which should be capable of outputting up to 2 A. If that's enough I could try running the scope from that and another battery (for negative voltage) and see the amount of noise inside the scope. This should allow me to see how much noise is generated by the adapter board and the main board by themselves.
Next, I could run the PSU with a dummy load and see how it behaves. If the previous step works out fine, I could easily test that out, otherwise I'd have to wait for access to another scope.
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I added a ferrite to the battery lead, but it did not help. I also removed the PSU from the scope and did some measurements with it connected only by cables. The Z-plate is still full of noise spikes and I think that the noise could be coming from the Z-plate to the PSU. The type of noise I previously described to me seems a bit stronger on the Z-plate than on the PSU ground. That should be expected, since I have ferrite on PSU to adapter board cable.
A few things to try out:
I have a linear PSU which should be capable of outputting up to 2 A. If that's enough I could try running the scope from that and another battery (for negative voltage) and see the amount of noise inside the scope. This should allow me to see how much noise is generated by the adapter board and the main board by themselves.
Next, I could run the PSU with a dummy load and see how it behaves. If the previous step works out fine, I could easily test that out, otherwise I'd have to wait for access to another scope.
I measured the current consumption for the 8.4V and -7.6 a while ago. The 8.4V used about 2.2A with no battery option. Here is a link to where I reported those findings:
https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/msg281838/#msg281838 (https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/msg281838/#msg281838)
If you have a 2A PSU I would try it anyway, it may be able to supply a little more, just watch for overheating. The info on the link should also be helpful to set up a dummy load.
I agree with your reasoning about the noise in the Z plate versus PSU GND and the ferrite, so I think that would be a worthwhile experiment.
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Yes, I get the new boards from Aidetek, but this was not easy. Owon don't want selling directly to me the adapter board. Why? I don't know.
The Aidetek starting to apply waranty cover to gnd-noise issues to their customers.
I'll have more information at the end of this month, about this.
...
Without the shield and using the short gnd probe cable the noise was around 50 mV.
Well, now there is not much difference.
Looks like 5mVpp better!
When the GND noise is that low a few millivolts less are hard to achieve. With the ferrites on my probes my noise is still a little higher than that. However, the position of the probe cables in respect to the scope don't have much of an effect.
I agree with the TomC, 6mVp-p isn't a big improvement but it is hard to achieved from 28mV to 22mV.
Also, it seems that your shielding works very good.
If you see at the capture with 22mV all the periodicaly noise (spikes) has gone and the only noise that remaining is only the base. Very good result :-+
...
Anyway, I did the backlight mod and it got rid of the peaks in its area. Results are same as lemon's.
...
It is fine, seems to work to all versions 3.0.
You thinking right about test with the external PSU to the adapter board, but have in mind that the circuit around of AOZ1094 is the biggest source of noise on this adapter.
My opinion is to modificate this area too.
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How can I save to external usb stick or to pc via Oscilloscope software a record waveform?
For example go Save->Type-Record->Mode-Record and click to Operate-Play, when you want to stop press simple the Click.
If you want to see what you have record follow the Mode-Playback->Operate-Play. With the Playmode-Loop the capture waveform plays without stop.
Just fine until now, but I can't find how this captured waveform can to export.
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How can I save to external usb stick or to pc via Oscilloscope software a record waveform?
For example go Save->Type-Record->Mode-Record and click to Operate-Play, when you want to stop press simple the Click.
If you want to see what you have record follow the Mode-Playback->Operate-Play. With the Playmode-Loop the capture waveform plays without stop.
Just fine until now, but I can't find how this captured waveform can to export.
As far as I can see, you can only save to internal memory. I don't see any way of exporting to USB stick or PC.
I also noticed that when I use this function it interferes with the AC trigger. Once I use it, AC trigger don't seem to work until I change to DC trigger. Then, when I change to AC trigger again it works OK.
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Firmware Upgrade for the SDS scopes ? :-//
While checking the Owon site for firmware updates I happened to notice that the RAR file for the 3.2 & 3.3 patch was slightly longer than the one I had downloaded some time ago. In addition, the date of the upgrade had changed to a later date. Knowing that Owon is a little unorthodox in the way they name and issue new releases, I went ahead and downloaded the file (took more than 15 minutes) and installed the patch.
As far as my scope is concerned, this is a different and improved firmware release even though it still has the same patch number that was released quite a while ago.
One thing I noticed is that the functionality of the LAN interface is better, I can again transfer images, a functionality that hadn't work for me for quite sometime now. The high memory depth transfer works most of the time up to 1M acquire length. However, my scope still freezes if I attempt a 10M transfer.
I also noticed that the firmware version on the About screen displays 3.2. I installed the patch a second time to see if would change to 3.3 but it didn't.
The last thing I noticed is that the "SCPI Command Line" button on the Remote Control Panel appears to be functional. I didn't try any commands, but it no longer emits an error message when you click it.
While at the Owon site I also downloaded the latest SDS manual. This is also a newer manual (V1.6.3). A quick look revealed that they have added the SDS7072 to the manual. They have also added and rearranged to the information for the PC software and LAN interface.
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I tried the SCPI commands, they all seem to work.
The one thing that puzzles me is the Load File button. I can create a text file with SCPI commands in it and load it via this button. The first command in the text file then appears on the command line and I can press SEND to execute it. But that's seems to be the end of it. I couldn't find a way to progress to the next command in the text file. So it seems that it only works for a single command per file, or perhaps is not yet completely implemented. If anyone finds a way to make this work more like a macro, please post it!
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How can I save to external usb stick or to pc via Oscilloscope software a record waveform?
For example go Save->Type-Record->Mode-Record and click to Operate-Play, when you want to stop press simple the Click.
If you want to see what you have record follow the Mode-Playback->Operate-Play. With the Playmode-Loop the capture waveform plays without stop.
Just fine until now, but I can't find how this captured waveform can to export.
As far as I can see, you can only save to internal memory. I don't see any way of exporting to USB stick or PC.
I also noticed that when I use this function it interferes with the AC trigger. Once I use it, AC trigger don't seem to work until I change to DC trigger. Then, when I change to AC trigger again it works OK.
Yes, I noticed the same function to internal memory but nothing to export. The Oscilloscope pc software has the save from hi memory depth but saves only static images.
The menu Save is a little complex, there is save output (internal or external) to Wave Type or Image Type that the usb stick works but the same to Record Type isn't.
Also, I noticed that the Record Function is only to view the waveform to loop or at once, not to stop this and zoom with Time button. If you try this you'll laugh a lot of...
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Also, I noticed that the Record Function is only to view the waveform to loop or at once, not to stop this and zoom with Time button. If you try this you'll laugh a lot of...
I had the same impression, it's a joke :-DD
Maybe there is a reasonable application, but for the life of me, I can't figure out what that may be!
By the way, there is a similar feature from the PC software that I tried last night. You got to set a data storage folder to store the BIN files, and then you can play them with the Auto Player. Uses gobs of memory. But here you can at least do a little bit more with it.
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TomC, I''ll look the pc software another time because I have the scope full unfit for painting with Contact Chemie 35 now.
By the way, I can't remove the last board, this of buttons and there is no any information at the video or service manual.
Have any ideas, how to remove it? Carrington, where are you?
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Pulls the buttons strongly, you can use a rubber band and a pliers. Roll the rubber band arround the button and strip with the pliers, but be careful.
Notes: Do not paint this part (red) cover it with adhesive paper tape, like a cigar. Use also the adhesive paper tape to cover the outer edges of the plastic housing, i.e. all around. You can glue too a foil of paper around the housing using the adhesive tape. By this way you do not paint where you should not. Please use a protective mask too.
Edit: Remember you need a full pot of EMV35, nothing remains. Also you need fill all the button holes with plasticine without dirtying the rest around. To clean the plasticine rest you can use use alcohol and cotton tipped swabs. Do not forget cover the hole for the screen with adhesive paper tape.
I forgot, does not spray the paint from afar, and sprayed with the pot in vertical. Better read the instructions.
Good Luck. :)
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The board in the photo above radiates a lot.
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TomC, how exactly the AC trigger does not work? I think that I used the waveform record function once on AC trigger and it seemed to work fine to me back when I did it. I don't remember if it was with the newest firmware.
Lemon, the only way I see that the recorded waveform can be transferred is to play through the recording frame by frame and then copy the waveform using wave or image types. This is very time-consuming!
A small update from me: I added the SMD capacitors from lemon's adapter board mod for the middle voltage regulator (specifically one 220 nF for D127 and one 220 nF in parallel with C33), but it seems that the result was negative.
I can now see a nice waveform on scope screen even with no probes connected and the peak to peak voltage with nothing in the BNC is around 32 mV. Previously it was around 26 mV. I'll try undoing the mod and see if that returns previous noise level.
After removing the capacitor going from D127 to ground, the noise level with nothing connected went back to normal.
I also managed to trigger on those "noise bursts" I mentioned several times before. Required settings for me were slope trigger, when=30ns, Threshold&SlewRate High level= 120 mV, Low level=- 120 mV. Now I'm almost completely sure that the noise is in fact coming from somewhere around the MC. I set the channel one to trigger on the noise and probed around with channel two. I placed the probe on top of almost every IC I could access and only near the MC did I see waveform on channel two synchronized with channel one.
It's also interesting to see that Owon expanded the SDS-E line to whole range of scopes. High memory seems to be an optional feature now. The other differences appear to be a slight update on of the shell and removal of the battery. I also noticed that it can be self calibrated with no warm-up period. In fact, they mentioned that in the new SDS manual as well. This seems a bit strange to me. Also since I'm bashing their autocalibration instructions, I'll mention this gem from the manual: "If the change of the ambient temperature is up to or exceeds 5?, the self-calibration procedure should be executed to obtain the highest level of accuracy." What's the point of mentioning the temperature of the change is up to or exceeding that value? Perhaps they meant equal or greater than 5?.
The SDS7072 has adjustable output for the scope compensation port. Frequency can go from 1 kHz to 100 kHz and duty cycle from 5% to 95%. I wonder why that would be a useful feature. I know that high frequency probes need higher frequency for compensation in addition to low frequency, but that high frequency is usually around 1 MHz. Also I'm not sure how variable duty cycle would help. Any ideas?
All in all, it seems they added four new models of scopes based on SDS7102. This seems a bit too much to me.
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Shit, I forget this :rant::
Covers the same part that you see in yellow, otherwise the paint will cause a short circuit.
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It seems that the push knob contacts are routed. Maybe they plan to add fine vertical setting in future?
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It's also interesting to see that Owon expanded the SDS-E line to whole range of scopes. High memory seems to be an optional feature now. The other differences appear to be a slight update on of the shell and removal of the battery. I also noticed that it can be self calibrated with no warm-up period. In fact, they mentioned that in the new SDS manual as well. This seems a bit strange to me.
The SDS7072 has adjustable output for the scope compensation port. Frequency can go from 1 kHz to 100 kHz and duty cycle from 5% to 95%. I wonder why that would be a useful feature. I know that high frequency probes need higher frequency for compensation in addition to low frequency, but that high frequency is usually around 1 MHz. Also I'm not sure how variable duty cycle would help. Any ideas?
All in all, it seems they added four new models of scopes based on SDS7102. This seems a bit too much to me.
?
rf-loop should know something about it.
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Yeah, it would be nice to hear about that new line. If I remember correctly, the SDS-E was targeted at educational market and that was the reason for the low bandwidth of the SDS5032E.
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Pulls the buttons strongly, you can use a rubber band and a pliers. Roll the rubber band arround the button and strip with the pliers, but be careful.
Notes: Do not paint this part (red) cover it with adhesive paper tape, like a cigar. Use also the adhesive paper tape to cover the outer edges of the plastic housing, i.e. all around. You can glue too a foil of paper around the housing using the adhesive tape. By this way you do not paint where you should not. Please use a protective mask too.
Edit: Remember you need a full pot of EMV35, nothing remains. Also you need fill all the button holes with plasticine without dirtying the rest around. To clean the plasticine rest you can use use alcohol and cotton tipped swabs. Do not forget cover the hole for the screen with adhesive paper tape.
I forgot, does not spray the paint from afar, and sprayed with the pot in vertical. Better read the instructions.
Good Luck. :)
Carrington, thanks for info.
I am write-typing quickly...already I have painting the back cover.
I''ll upload my results when I finished...
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Carrington, thanks for info.
I am write-typing quickly...already I have painting the back cover.
I upload my results when I finished...
You are welcome.
Ok, quiet, leisurely. It dries pretty fast, but is better let it ~12h to cure.
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Firmware Upgrade for the SDS scopes ? :-//
Yes. :'(
While checking the Owon site for firmware updates I happened to notice that the RAR file for the 3.2 & 3.3 patch was slightly longer than the one I had downloaded some time ago. In addition, the date of the upgrade had changed to a later date. Knowing that Owon is a little unorthodox in the way they name and issue new releases, I went ahead and downloaded the file (took more than 15 minutes) and installed the patch.
Over an hour to me.
While at the Owon site I also downloaded the latest SDS manual. This is also a newer manual (V1.6.3). A quick look revealed that they have added the SDS7072 to the manual. They have also added and rearranged to the information for the PC software and LAN interface.
It's a little disconcerting, they don't stop making changes.
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TomC, how exactly the AC trigger does not work? I think that I used the waveform record function once on AC trigger and it seemed to work fine to me back when I did it. I don't remember if it was with the newest firmware.
After using record, and then turning it off, I ran the scope normally to view a 10MHz 180mVpp waveform. The trigger was set to AC, and I couldn't get a stable trigger, going up and down on the trigger level didn't help. I then changed the trigger to DC and it worked normally. When I changed it back to AC it also worked correctly. I tried this several times with the same results. Seems like some kind of firmware bug. Not very alarming however since you can get it back to work fairly easily.
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Also since I'm bashing their autocalibration instructions, I'll mention this gem from the manual: "If the change of the ambient temperature is up to or exceeds 5?, the self-calibration procedure should be executed to obtain the highest level of accuracy." What's the point of mentioning the temperature of the change is up to or exceeding that value? Perhaps they meant equal or greater than 5?.
Reading Chinglish requires some imagination! :)
However, I'll have to give them credit for producing a more readable manual than what you typically see from other Chinese manufacturers. For example, my Tenma 72-7730 multimeter (UT71B). I was so disappointed with the manual that I re-wrote it to suit me.
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What surprises me the most is about the whole manual side is the usefulness of the included help. It almost covers whole manual and is pretty simple to use. My only complaint about it is the fact that if the voltages have jumped out of the bottom bar, manual doesn't hide them.
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From what I saw the there are two products for Contact Chemie 35 EMV.
The first one is that the Carrington uses. This is the new product of 35 EMV, it contains highly conductive copper pigments in acrylic resin. Shielding attenuation: 60-65dB.
(http://brain.pan.e-merchant.com/8/1/10934518/l_10934518.jpg)
The other one is that I found, an older product of 35 EMV that it is a shielding spray with Nickel base.
(http://www.comicflyer.de/Forenpics/fpv/emv35nickel.jpg)
The price both of them is differente with the most expensive that with the cooper pigments in acrylic resin.
The painting is finished and the final optical result is perfect! I have removed all the adhesive paper and plasticine and let it to dry completely for 24 hours.
Tomorrow I'll upload photos with some measurements.
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I've been playing with the Oscilloscope software's Auto Player feature and after tripping over myself a few times decided to write down the steps to get it to work. So I thought I'll share this cheat sheet with those of you that may want to further investigate the usefulness of this feature.
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To use the Auto Player feature first go to Port Settings.
1. Click the check mark box for "Save data file automatically to below directory".
2. Browse to an empty folder and press OK, or browse to a folder of your choice and click "Make New Folder", enter the folder's name, and press OK. The correct folder path and name should appear in the directory field.
3. Use Windows Explorer to navigate to this folder so you can watch its content. There is a bug in the software that can start filling this folder very rapidly with new numbered folders (1,2,3,4.....800,801, etc.).
4. Set the "Keep Getting Delay(ms):" to the interval in ms that you want to have between captures. For example, 3000.
5. Capture some data by clicking "Keep Getting Now!", or click "OK" and then click the "Continue Data Download" icon on the toolbar. On the folder you are watching a file named "filename.ini" and a folder named "1" should appear.
However, you may see a bunch of numbered folders being created. If this happens, CLOSE the Oscilloscope application. This is the bug mentioned on step 3. Delete the folders and try again.
During each capture interval a new data file is created and stored in folder "1". A list of these file's names is kept in filename.ini to keep track of the sequence in which the data files are recorded. At the bottom of the Oscilloscope application window the path and name of the current destination data file and a progress bar are displayed. This information is automatically updated during each capture interval.
6. To stop capturing data click the "Stop Data Download" icon on the toolbar.
7. To setup the playback of the captured data click the "Auto Player" icon on the toolbar.
8. Set the desired "Play Mode" and the "Time Delay" between frames. Choose "Turn" to playback the captured files in the same sequence that they were recorded, choose "Reverse" to play them back from last to first. During playback each file represents a frame, the "Time Delay" is the dead time before the next file is read and displayed.
9. Click "Add..." and browse as required to add the folder created during step 2 to the "History:" list. Choose this folder from the history list.
10. Click the "Play" button to begin the playback. During playback you can click "Pause" and use the "Next" and "Previous" buttons to manually step from one frame to another. Automatic playback ends once the last frame is reached, there is no loop option and you must press "Play" again to repeat.
NOTES:
There is no built in mechanism to edit the history list. However, to delete folders from this list you can physically move them or delete them with Windows Explorer. When you close/open the Oscilloscope application, any folders in the history list that can't be found will be automatically purged from the list.
It's possible to create your own capture sequences for playback. The filenames don't seem to need any particular syntax, so you can name the BIN files of your choice at will. The filename.ini file must contain these filenames in the sequence you want to playback the BIN files. If the BIN files are on a different folder this needs to be reflected in filename.ini with a path.
For example, for a folder in the history list named "Data" which contains the files, TomC_1.bin, TomC_2.bin, TomC_3.bin, the filename.ini file within "Data" should look as follows:
TomC_1.bin
TomC_2.bin
TomC_3.bin
or as follows if you want for example to play TomC_3 before TomC_2:
TomC_1.bin
TomC_3.bin
TomC_2.bin
Now let's say that we want to put these 3 BIN files in a subfolder named "1". In this case the filename.ini file within "Data" should look as follows:
1\TomC_1.bin
1\TomC_2.bin
1\TomC_3.bin
If you rename existing BIN files or edit existing filename.ini files, some of the previous information may still be stored in temporary memory. As a result Auto Player may not work as expected and you may need to Close/Open the Oscilloscope application to set things straight.
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There are times when static images don't tell the whole story of what's happening when scoping a particular event. Perhaps this feature may be useful in those cases to capture a more dynamyc reprensentation of the event. It seems to me that the data folder created with this feature could be compressed into a ZIP file and posted in this forum when a dynamyc representation is more appropriate.
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TomC, thanks for the intro about this software function.
It is the same like record in save menu.
But there is same behaviour here, no export of this sequence.
Today I have finished with all works about emv35 shielding and fit the boards.
The painting is OK, but the result is worst than before but I''ll talk about this later.
I''ll show here some photos from procedure.
First, I covered all the holes with plasticine, and the whole area with adhesive paper tape or insulate tape. I used a whole spray for this (200ml).
As you can see at the two details the shielding of Nickel is very good.
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Today I have finished with all works about emv35 shielding and fit the boards.
The painting is OK, but the result is worst than before but I''ll talk about this later.
I've disassembled again, Oh men you should apply plasticine from inside. Anyway is not important.
But there is another problem, after a few days running I discovered cracks in the hotter areas (different dilation). :--
Woow you got worst results! :-//
Well I made other changes, in addition to painting it:
- Add a ferrite in the flat screen cable.
- Modify the screen assembly.
There is a solution, a bath in hydrochloric acid.
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TomC, thanks for the intro about this software function.
It is the same like record in save menu.
But there is same behaviour here, no export of this sequence.
Today I have finished with all works about emv35 shielding and fit the boards.
The painting is OK, but the result is worst than before but I''ll talk about this later.
I''ll show here some photos from procedure.
First, I covered all the holes with plasticine, and the whole area with adhesive paper tape or insulate tape. I used a whole spray for this (200ml).
As you can see at the two details the shielding of Nickel is very good.
Looks like a very good job! :-+
I don't understand why it would worsen the results. Is there positive continuity between the shielding and the Z plate?
As for the Auto Player feature, the one advantage I see is that even though you can't export the sequence back into the scope, you can make the captures available to others. Even somebody that don't have an SDS scope could download the Oscilloscope application and use it to play captures from somebody else.
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But there is another problem, after a few days running I discovered cracks in the hotter areas (different dilation). :--
That's not good! :(
Is there a difference in performance since these cracks appeared?
From what I see on the picture it doesn't seem bad enough to affect the shielding effect.
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Oh men, you did not see this: :palm:
https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/msg292492/#msg292492 (https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/msg292492/#msg292492)
I'm sorry, I it forgot in the first post.
You also paint the internal battery housing. Why?
"Is there a difference in performance since these cracks appeared?
From what I see on the picture it doesn't seem bad enough to affect the shielding effect."
It does not seem, would have to check it. This can cause a short circuit if a piece breaks off.
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First one inspiration, after a long expiration, I must to relax because my nervous system is going to break!
1) when fit all boards, I observed that the shielding has a continuity with Z-plate. Carrington, the area back of the Probe Compensation has cleaned before, because it had painting. No any shorting there!
This is no normal, but with this situation I take some measurement.
Base line 2mV BW limited...more than I had before shielding
Base line 5mV full BW....more than I had before shielding
Gnd-noise non isolate....although there is a low base noise 20-26 mV unfortunately there are a lot of spikes to 45-60 mV
2) unfit all boards and isolate some areas as opposite of bnc and the upper of horizontal buttons. I cleaned all those signs that catch the screws from shielding. Now there is no any continuity between the shielding and Z-plate.
But the gnd-noise is the worst! (gnd_noise_isolate) 50-64mV.
I put some internal ferrites to the flat cables but nothing...
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Well I tested again without shielding. And I've discovered something new, look at the images, the only difference is that the button board does not contact with the main board at gnd screw, except for the last.
This thing is worse than a toothache, I don't understand why that happens with yours oscilloscope. :palm:
I have no more ideas, I give up.
Edit: Sorry for the quality of the images, I tried with a flash, but the screen goes black.
Sorry, I have to leave it for today. See ya. ;)
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I''ll try with your test and I come back, tomorrow.
Now, I am very tired to think something.
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I couldn't to wait...
All what you see is true. With the button SDS_Key board close to z-plate the gnd-noise is minimum (I measured 30-36mV, see attachment).
With the button SDS_Key board away from z-plate (2 cm) the noise is increasing to 40-56mV, see attachment).
Conclusion, the choice how you enclosure this scope is nervous breaking and the results of shielding will be a magic show!
I'll try to find what is happening here!
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I couldn't to wait...
All what you see is true. With the button SDS_Key board close to z-plate the gnd-noise is minimum (I measured 30-36mV, see attachment).
With the button SDS_Key board away from z-plate (2 cm) the noise is increasing to 40-56mV, see attachment).
Conclusion, the choice how you enclosure this scope is nervous breaking and the results of shielding will be a magic show!
I'll try to find what is happening here!
Lemon & Carrington,
There may be more to this than just random effects. The following is an excerpt from an article at:
http://www.4emi.com/shield.php (http://www.4emi.com/shield.php)
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There are two principle mechanisms present in all shields, and these are reflection and absorption.
When an electromagnetic wave traveling through space encounters a shield two things happen.
First, much of the energy is reflected and then second some of the energy that is not reflected is then absorbed by the shield; only the residual energy emerges from the other side of the shield. These two effects of reflection and absorption are independent from each other, but when they combine together, they produce the overall shields true effectiveness.
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The one thing that strikes me as the probable culprit is the reflections. There are many components in the scope that radiate EMI, but without shielding a lot of it dissipates in the sorrounding area and doesn't affect nearby circuits. With the shielding this EMI is reflected onto other nearby circuits causing noise problems that weren't there before.
The shielding is doing its job properly, is preventing the EMI from escaping the confines of the scope's cabinet. But the side effect is that this energy is now internally reflected unto other circuits.
If it was possible to confine the EMI of the major emitters to a smaller area, with a smaller shield, perhaps the effect of the cabinet's overall shielding would produce better results.
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This theory explains exactly what it is happening here.
The case of Owon is very thin and all boards are close together. This isn't good for avoided of EMI.
Yesterday, I done a lot of combinations. One thing is sure, when all boards is out of the case and are close together the gnd-noise is decreasing, I measured until 25mVp-p (10X).
Now, with the shielding of Nickel the emi reflects everywhere and I can't to fall it under 45-50mV with the case closed. I am not going to do any to remove the shielding now, before I take the new boards that I wait, perhaps they have different behavior with the shielding.
Carrington, the problem with the cracking of shielding is not very big. Perhaps the temperature there is high and cracking the layter, perhaps you had apply very fat layer of shielding.
I was looking your internal photo, I am very sure that you have continuity btw z-plate and shielding now.
Look at the marks that I have put to your photo.
The three yellow cycles at the bases of bnc and the four corners of tft display cause a continuity between the shielding and z-plate.
Please, can you feedback about this?
I covered all metalic frame of tft display with a cotton adhesive tape and a thin O-ring to base of each bnc. With that I don't have continuity with z-plate, but I haven't better result, just different!
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I finally got done upgrading my Variac, there is a picture and schematic posted here. (https://www.eevblog.com/forum/chat/show-your-favorite-and-mostly-used-benchtop-psu/msg293215/#msg293215)
The next step is to put together a way of independently powering up my old PSU and setting up some dummy loads. Hopefully I will get this done quicker than the Variac. However, I want to do this in a way that accessing the components for scoping is convenient but at the same time simulates as closely as possible the environment when it's installed inside the scope.
From 0-140VAC the Variac's output is now isolated from the mains, so hopefully scoping signals referenced to GND-A will no longer be a problem. I now also have the ability to output 0-280VAC, so I can perform tests at mains voltages used in other countries. Unfortunately, I didn't have an extra power isolation transformer to implement this capability with mains isolation. So at voltages greater than 140VAC scoping signals referenced to GND-A will still be a problem.
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Another update from me: I managed to track down those noise bursts that happened after switching.
I changed the LM324 with LM224, but it wasn't the LM, since noise was there even with LM removed. At least the extended temperature range should come in handy, since the PSU board gets pretty hot when running from the mains.
Then I went on to change all the components near the MC34063A. I the ON Semi MC with another ON Semi MC, replaced the coil with a 100 µH toroidal coil. It changed the frequency of operation for the MC, but the noise bursts remained. One thing that surprised me was the increase of range at which I can pick up the noise from the coil with scope probe. If I remember my magnetics course correctly, most of the magnetic field should remain within the coil. I can't remember how electric field would behave. For some reason I expected its emissions to be harder to pick up.
Then I replaced the SR160 diode with a MBRS1100T3 SMD diode from ON Semi. If I read the datasheet correctly, it looks a bit better than the SR160. It has lower capacitance and higher current ratings, but the forward voltage looks a bit higher than on SR160. In any case, that didn't help.
After that, I removed the current sense resistor and those noise bursts I had after switching are now gone. I'm thinking of putting a picofarad range capacitor in parallel with the resistor, since I'd like to have it there in case of overcurrent situation.
Interesting thing is that duty cycle remains erratic even with the current resistor removed. Switching noise still remains.
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Well done, TomC. I'll wait for your result.
I would like to test the scope without the Owon PSU, but I am thinking how manipulate the trigger output of the flat ribbon.
How is the right way to be done?
Sure, I need two independent voltages by -7.6V and 8.4V - this is easy I have the appropriate psu - but the ac trigger output?
When dismantle (unfit) my scope to applying shielding, I found the time to take some photos to the others boards.
Here are with the full resolution, only an amount of compression for smaller files.
The photos are from the two buttons boards, the one is L schema of buttons (H1..H5 horizontal and F1..menu off vertical) the other is main menu buttons. Also there are photos from the mainboard, both of sides.
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I would like to test the scope without the Owon PSU, but I am thinking how manipulate the trigger output of the flat ribbon.
How is the right way to be done?
Sure, I need two independent voltages by -7.6V and 8.4V - this is easy I have the appropriate psu - but the ac trigger output?
No need this trigger signal if you do not select trig source "AC". Afaik, this is only for this use.
(Note that it is also case if power come from battery. There need only Vbatt (~6V(min) to ~8.?V (max8.4V)) and -7.6V)
(I have used it also with external +8V, -7.6V, +5.5V and +3.3V when I inspect TFT bus noise and front panel noise.. Also TFT backligt can drive with external Constant Current source (max/and normal 100% brightness around 180-200mA))
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Hello everyone!
TomC:
When I get time I will read the article. Reflection and absorption, that's right, but who knows what's happening inside. We do not have the means to do a simulation, we only can make test. Woow...
Once shielded it only one thing is clear all the electrics fields are confined inside. Now, clearly absorbing materials type FFAM would help.
But I'm starting to wonder if it is worth spending more money on this thing.
Lemon:
Yes the shielding and z-plate have continuity but I need to check at which points. Will be later, I'm very busy but don't worry I will confirm you where it makes contact.
The oscilloscope does not need the ac trigger output to work, when running only with battery does not have it.
Your "motherboard" is very different to mine, and my ADC is from National.
AndrejaKo:
Woow, you removed the current sense resistor and noise bursts gone. LOL... Unbelievable.
Switching noise still remains. :--
Is needed do more testing, but now I can't.
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Well done, TomC. I'll wait for your result.
I would like to test the scope without the Owon PSU, but I am thinking how manipulate the trigger output of the flat ribbon.
How is the right way to be done?
Sure, I need two independent voltages by -7.6V and 8.4V - this is easy I have the appropriate psu - but the ac trigger output?
When dismantle (unfit) my scope to applying shielding, I found the time to take some photos to the others boards.
Here are with the full resolution, only an amount of compression for smaller files.
The photos are from the two buttons boards, the one is L schema of buttons (H1..H5 horizontal and F1..menu off vertical) the other is main menu buttons. Also there are photos from the mainboard, both of sides.
I agree with rf-loop, there is no need to worry about this trigger, is only used when you select AC trigger as the source.
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After that, I removed the current sense resistor and those noise bursts I had after switching are now gone. I'm thinking of putting a picofarad range capacitor in parallel with the resistor, since I'd like to have it there in case of overcurrent situation.
Interesting thing is that duty cycle remains erratic even with the current resistor removed. Switching noise still remains.
Andrejako,
I would try adding an electrolytic capacitor at or near the MC's VCC pin. Just in case the 8.4V don't have enough filtering at that point.
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Thanks guys for the info.
@ Carrington = I''ll waiting for your feedback about continuity btw z-plate and shielding. It is important to me. Thanks a lot. As I saw you have an 8102, it is logical to have differently mainboard.
@ AndrejaKo = Nice observation but at the final all this psu is fully noising. At the end, I'll wait the TomC's work about this.
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Andrejako,
I would try adding an electrolytic capacitor at or near the MC's VCC pin. Just in case the 8.4V don't have enough filtering at that point.
I added a 1 mF low ESR aluminium electrolytic capacitor directly to the hole where the current sense resistor connected to Vcc pin and the second lead to ground next to some exposed resistors. It made no improvement.
@lemon
No, actually they changed their ADC vendor, if I remember correctly sometime in 2012. From serial number of your board, I see that it's the same batch as my old board. I remember that some time after that, they moved to National ADCs with secret part numbers. I think rf-loop wrote about that several months ago, but I can't find the post right now.
On the bright side, of all this PSU noise, at least I have an entertaining way of learning a bit more advanced electronics. My friends spend their time tuning their Yugos, while I spend my time tuning my scope :)
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Your "motherboard" is very different to mine, and my ADC is from National.
Functionally exactly same. "RuiFeng" MXT2002 is functionally clone of ADC08D500.
There can use both. (but physically not directly pin-pin becouse "RuiFeng" add extra (n.c.) pins to every corner)
MXT2001 is 2x1GSa/s (SDS8102) and MXT2002 is 2x500MSa/s (SDS7102).
Owon have used "RuiFeng" and other manufacturers ADC08D500 in SDS7102
Perhaps also some Rigol use "RuiFeng" ADC's.
Page from MXT "User manual"
and perhaps this picture is from MXT factory.
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I added a 1 mF low ESR aluminium electrolytic capacitor directly to the hole where the current sense resistor connected to Vcc pin and the second lead to ground next to some exposed resistors. It made no improvement.
AndrejaKo,
We are running out of options here. I was wondering, it seems that you have spares of most of the components for the -7.6V circuit, perhaps you could breadboard a clone of this circuit and see how it behaves. It's sort of a desperate measure, but you have tried just about everything else. It sort of comes down to something basically wrong with the design, or some influence on it by the PSU's circuit board environment.
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...
@lemon
...
On the bright side, of all this PSU noise, at least I have an entertaining way of learning a bit more advanced electronics. My friends spend their time tuning their Yugos, while I spend my time tuning my scope :)
I agree totaly with you. We learn with it, it is like that we interesting to improve. :-+
Your "motherboard" is very different to mine, and my ADC is from National.
Functionally exactly same. "RuiFeng" MXT2002 is functionally clone of ADC08D500.
There can use both. (but physically not directly pin-pin becouse "RuiFeng" add extra (n.c.) pins to every corner)
MXT2001 is 2x1GSa/s (SDS8102) and MXT2002 is 2x500MSa/s (SDS7102).
Owon have used "RuiFeng" and other manufacturers ADC08D500 in SDS7102
Perhaps also some Rigol use "RuiFeng" ADC's.
Page from MXT "User manual"
and perhaps this picture is from MXT factory.
Many thanks for this info, rf-loop.
I have a query about this. If you see with attention the photo "Mainboard downside SDS_V3.3.jpg" that previous I have uploaded, there are some bridges to the left and up side of the Chrontel chip. Is that normal? Also, I must to examine the C146 at the left of this chip, in photo seems like to be damaged or to has a bad solder.
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... there are some bridges to the left and up side of the Chrontel chip. Is that normal? Also, I must to examine the C146 at the left of this chip, in photo seems like to be damaged or to has a bad soldier.
There is Chrontel datalines D23,22,21; 15,14; (in picture looks like solder "bridge/GND")
Then you see data lines D7,6,5 also connected to GND.
This Chontel chips is some amount complex. There is example 185 different modes (0-184). In many modes data lines have different use. (Table 7: Input data format)
Just example (not this case) mode 2. There is 3x8 bit data lines, but in this case Red use 5 bit, Green use 6 bit and Blue use 5 bit and other data lines 0.
My "quess" is that it just need these data lines only to GND? But I do not know what is selected mode exatly.
Chrontel 7026 SDTV/VGA Encoder (https://app.box.com/s/lkuk7bcylfjltuujsghl)
If you mean C164, it really looks very extremely bad in picture. Hand repaired(?) soldering with very poor skills? (also overall over the board solderings looks like there is some kind of problem in process?) Is it some kind of monday morning production?
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Shielding+Zplane:
Blue direct contact.
Red, indirect contact. (Also through all gnd srews of Button_2F).
Green, Contact, with back cover.
Screen+Zplane:
Direct contact between the screen and the Zplane.
Zplane:
New ferrites added.
Detail_1:
Chrontel.
Detail_2:
Broken Inductance (It came broken from the factory).
This DC/DC converter power directly the whole DAC, analog and digital, any filter between. :palm:
PSU_R:
Red, avoiding gnd loops (I don't believe that their impact be noticed).
Main_R:
National ADC (Lemon, my input stage is different from yours).
U59 (7905) power the input stage with -5V, directly connected to -7.6V PSU.
Lemon, could you try the shield case without the buttons board inside?
Thanks.
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Lemon this is the board to pull out of the case.
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Different input stages.
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This (lemon version) more low noise and higher BW (and less power consumpting) front end (before ADC) have been also quite long time.
With this front end there have been ruifeng ADC and now also National.
lemon board is, if I understand right, from 2011.
This lemon version is developed from old "original" front end what was in production when this long original topic start by marmad. This original "first generation" front end also mechanical construction was not good and it was also noisy. (it can see in old noise level tests (not related to this SMPS noise issue) (also there was big advantage in bandwidth/risetime)
After this lemon picture version there have been 1 major change (analog front end designed nearly totally new - using now old and quite good two pathway principle (principle for two pathway front end originally designed by Tektronix) and also some smaller changes. In this construction 7102 BW drop some amount but it is still very good for 100MHz scope but in other hand, there was quite big advantage in front end random noise level.
I have made mistake when I have looked my stored pictures and thinking confusing amount of different versions.. and just accidentally think lemon version wrong.
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This (lemon version) more low noise and higher BW (and less power consumpting) front end (before ADC) have been also quite long time.
rf-loop then what are the main differences between the Lemon main board and mine?
Thanks.
Edit: Lemon, I just noticed that mine does not have that plastic (red), and therefore makes contact with the gnd of Button_2F board.
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Is this what I think? Power to digital and analog part separately, if so if we can add a low ohm FB.
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This (lemon version) more low noise and higher BW (and less power consumpting) front end (before ADC) have been also quite long time.
rf-loop then what are the main differences between the Lemon main board and mine?
Thanks.
My apologies. I have downloaded many pictures collected from forum etc becouse it is more easy look when not need search forum long threads and not only this thread.
I have mixed now some pictures, perhaps becouse lemon and you have different shield box (without trimmers adjustment holes) over front end other side and then looked wrong BNC side picture (older version) and of course then think it have this older front end version)
In older version there was not these trimmers (resistor) but only capasitive adjustments and these was also other side of PCB.
Now I look more carefully here directly in forum agen these pictures and also my own and collected pictures and now I'm even more confused with these many different versions but it was my mistake I think lemon version is more old than it is.
But in lemon version there is not these holes for adjust trimmer resistors or there is not at all these trimmers.
I have seen these (R)trimmers only in Owon analog front end version what is made partially with separate discrete fet's. But now I'm not sure about anything... more and more confused with these many more or less different versions.
How many different versions they have? Who knows...
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Lemon, could you try the shield case without the buttons board inside?
Thanks.
I do it tomorrow.
I see that we have the same main button board version, some minor routing differences at the side with the bnc face of mainboard, I don't see any differences to trimmers there.
The main differences about our versions are to the other side with the most IC's, some different IC's companies, you have more trimmers but for my opinion is normal not because you haven't different version but because yours mainboard is for 8102 with 2GSa/s and mine if for 7102 with 1GSa/s.
Thanks rf-loop for the datasheet of Chrontel but I can't to find answer to my question there. I see the capture of Carrington that his Crontel has clear all the legs and I am thinking what is going to mine.
Is it different configuration that must joined some legs or it is bad production? I took one macro photo of this IC, see at attachment photos.
I am thinking to send them to Owon for their respond about this.
I am a little nervous about this, because at this area around there are two bad soldering components, the one is capacitor that we said (it isn't damaged, only very bad soldering) and the other resistor very closer to the IC.
If you see with more attention at the macro capture photos, the joined legs have the same "ground planes" under. If there are common paths, why they applied extra joined with soldering? Weren't enough the common paths?
Of course from datasheet the main purpose of this IC is to encoder the signal to vga output. I don't see any problem with the external TFT monitor.
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Very sloppy soldering! :--
I think rf-loop is right, some kind of production problem and they were trying to salvage some (or all) of it with hand repairs. :palm:
They may have had some of the bridged pins come loose in some boards during that production run, and decided to solder them by hand on all the boards just in case. ::)
The sloppy soldering and the decision to ship subpar boards is a blackeye for Owon in my opinion! :--
I wouldn't blame you if you take them to task over this, and at least let them know that this behavior has not gone unnoticed! >:(
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Detail_2:
Broken Inductance (It came broken from the factory).
This DC/DC converter power directly the whole DAC, analog and digital, any filter between. :palm:
In my opinion, to ship something with broken components is not cool either! :--
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There some versions
old front end amplifier and then more new with discrete FET's
Between these there is also other version still with IC front end amplifier.
And between these versions, I suspect is lemon version? Perhaps still
this IC amplifier but physically different topology (when they change circuits to other side of PCB)
(here is not this one middle version picture)
Major change was change from IC amp to discrete FET amp.
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Looks like I have one more problem to add to my list of troubles with this scope:
After being turned off for a while, trace appears in random location. It does self-calibrate fine and after self-calibration it works fine, unless it's been powered off for a while. I took apart the whole scope and inspected everything in great detail. There were a few minor issues. One of the not so minor were horrible joints of CX1 capacitor on the input filter. They were so bad, I could move it by hand and there was even a bit of lifted trace there. I'm a bit embarrassed I did not notice this before.
Anyway, on the main board, there's a rechargeable lithium battery marked MS621FE whose voltage is 2.749 V. I'd expect it to be a bit higher, since the scope was running for quite a while before being turned off last time, but the value is within the datasheet limits, so I guess it's fine. Also the scope kept the date and time, so it looks like the auto-calibration data isn't lost.
With this main board, I did have some drifting with temperature on channel two, but it was a few millivolts. This seems like a systematic problem and running the scope for some time doesn't change the difference, except for the small amount of drift that was there before.
I'm really starting to thing that this scope is a bit cursed. :)
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2.75V is mine battery, too.
What to say....all of these are problems of production line. Chinese people learns easy but no with our moneys!
Before one month I bought a new Rigol DP832 psu and there was a production critical fault to one board, but Rigol quickly corrects (twice) this fault and continues to coverage the customers.
Nobody is perfect but the aftersales services is important to customers.
...
Edit: Lemon, I just noticed that mine does not have that plastic (red), and therefore makes contact with the gnd of Button_2F board.
Done and this test without any significant result, same noise (see at the attachment file).
Have in mind that with this test, dosen't work the Ch1, only Ch2.
By the way, there is a possibility the fault to be from the non continuity of shielding between the two cases? I can't to explain better (see the arrows at the capture)
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If it could be, because then is not properly a Faraday cage. I'm thinking that the Zplane can be like an antenna deflector, and therefore the shielding makes it worse, and would be necessary, to isolate the different zones inside, and this is very difficult.
However I've tried to isolate the area (with the plastic) and the noise increases by about 10mV. Also, if not screwing all the screws that attach the Zplane with the shielding the noise increases other 10mV.
I've also tested with the board Button_2F outside and again the noise increases.
The DC/DC converter that you can see on image Detail_2 generates a lot noise. Rf-loop says that it does not affect but sorry, I do not agree.
The next test will be with the whole scope and probe inside a Faraday cage, because I can not get off of that tone on 106.5MHz, I think that comes from outside.
Note: Yes, the BNCs make contact whit the area marked in yellow.
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Yes, mine it isn't a perfect Faraday cage but the logic says that in this case the noise will be worse when the back cover is complete open. Mine there is no any significant difference it the back cover is closed or not.
Which area isolated by plastic?
Before, when the back case was open the noise was a little worse, now the situation is more complex and a loose tightening of screws make a difference!
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The next test will be with the whole scope and probe inside a Faraday cage, because I can not get off of that tone on 106.5MHz, I think that comes from outside.
That's a very interesting experiment. My feeling is that you are right and it does come from the outside. But the experiment should prove this beyond the shadow of a doubt. I'll be looking forward to the results!
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I agree with lemon, with or without the back cover in my case not much difference too, the Zplane does its job. However I think that is better if the back cover is installed. In my case the shielding of the front cover is very effective. I just added a few sheets of aluminum inside (look at attachments) and see the result. It joins the buttons with internal shield. Sorry for the quality of the images. I can't turn up the brightness of the screen.
The area isolated with plastic was on top of the input stage shielding, in my case is better if this part is not isolated.
The test with the scope and probe inside the Faraday cage, not work as expected. I'm still wondering why.
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The noise of the two first is something 25mV (I can't to see clearly). The last isn't clearly to me (I must to see to my other display at my office that it have better color gamut) but I see that there is no any periodical noise.
Have you got any photos about your works with aluminum sheets, I can't understood why are you doing? Have you joined the gnd area of pushable buttons together?
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The noise of the two first is something 25mV (I can't to see clearly).
In previous images, respectively, 12, 24, 16 and 16 mV.
Have you got any photos about your works with aluminum sheets, I can't understood why are you doing?
I've been doing more tests, and I think that the previous improvement is due more to DSC04397.jpg / DS04398.jpg.
Have you joined the gnd area of pushable buttons together?
This is what I did, see DS04393.jpg, but in fact profits nothing.
Anyone know what this is (DSC04395), comes from the lcd, psu ...?
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If it could be, because then is not properly a Faraday cage. I'm thinking that the Zplane can be like an antenna deflector, and therefore the shielding makes it worse, and would be necessary, to isolate the different zones inside, and this is very difficult.
....
It is done and this test without success. Now I am thinking what is the best solution to removed without damaged the plastics and logos.
Carrington with the last yours photos, I understood complete what you have done.
I repeat the conditions of your last photo, it seems that this pattern exist always but a little, magnify a lot of on lcd.
I make a video on that.
P9219431 (https://www.youtube.com/watch?v=Wwo-MtMHtRw#)
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I done the same test to my lab pc tft display. The result has 100% same pattern and causes from tft display.
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I done a test with independent main psu.
For this reason I used a Rigol DP832 Triple Output PSU. This psu has a low noise threshold (3.5mVp-p)
I gave it a +8.4V/2.5A and -7.6V/0.5A power supply to adapter board.
From what I saw, the ampere consumption doesn't bigger than 1.43A with 0% backlight until 1.55 with 100% backlight for 8.4V.
The -7.6V has stable ampere consumption of 0.160A
All the test was with the two case of scope closed.
There is no any improvement about noise, exactly the same.
It seems that Owon psu as is now, does the job well.
By the way, I make two videos, the first one with the output psu the second one with normal ac power supply of Owon.
The only difference was the effect of ac wave of 50Hz to the Owon psu, this phenomenon of course doesn't exist with the output psu.
P9219432 (https://www.youtube.com/watch?v=Glr1u6Y8Oxw#)
P9219433 (https://www.youtube.com/watch?v=UE0g8sgjiQc#)
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Is interesting confirm that all have this source of noise. In my case the highest peak occurs in the connector between mainboard and DC/DC adapter. Strangely with the probe on the screen barely appears this noise, may be because I have the screen completely attached to Zplane, I don't know.
I leave it, this instrument no has solution, my oscilloscope have this noise (lcd) as common mode noise everywhere (with or without shielding). I discovered this noise inside the Faraday cage, with 5ms time base, previously I focused only on 500 and 100us time base. I tested too placing a ferrite above on this connector (see attachments), but that place (connector) does not support it due of its shape.
Before the main source of noise was the PSU and DC/DC adapter, now that they have corrected their novice failures on these boards, we can see the influence of other novice error even worse to correct. As I said there is no solution, requires a total redesign. Fortunately the influence of this common mode noise is not very high, and the instrument is usable.
Owon should have used a more appropriate connector or at least should have spent more pins to gnd, but not did, and that says a lot... :palm:
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I think that before with the old psu and adapter, the main source of noise was there.
Now, that major noise decreased, we see and the others common noises from the other boards.
I think the same that you, that it is at their limit - let it as be!
I am very sure that you have seen that but I upload one more video that appears how sensitive is!
Please, if someone know a good method for removing Nickel shielding, it'll be welcome.
P9219434 (https://www.youtube.com/watch?v=OCEc8aDsN0E#)
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If it is a plate on plastic a soaking in a concentrated strong acid will strip it quite fast. Aqua Regia will strip it in a very short time, though the plastic under it may be damaged a little. Other methods are to electrodissolve it by using it as an anode in an electrochemical bath, as is used to do electropolishing of stainless steel parts, though you will have to gradually immerse it so the anode connection is placed in last to be the final part to dissolve. If you are just trying to cut it into sections then use a small sanding disc in a dremel or similar tool. If you want to leave sections paint them to make them non conductive ( or cover with wax to repel water) then electrodissolve the remaining uncoated area.
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Using hydrochloric acid and hydrogen peroxide, and mixing all in equal quantities, should work.
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Thanks for the info SeanB and Carrington.
I am afraind the plastic cases a lot of. Also I am afraid the logo, letters e.t.c
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Thanks for the info SeanB and Carrington.
I am afraind the plastic cases a lot of. Also I am afraid the logo, letters e.t.c
Well, wait I test it first to see what happens.
After all afternoon, see attachments.
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Thanks for the info SeanB and Carrington.
I am afraind the plastic cases a lot of. Also I am afraid the logo, letters e.t.c
Well, wait I test it first to see what happens.
After all afternoon, see attachments.
The powdery substance on the second attachment, does it rub off clean, or did you get damage to the lettering and logos?
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Thanks for the info SeanB and Carrington.
I am afraind the plastic cases a lot of. Also I am afraid the logo, letters e.t.c
I can't be sure, but looking at your last video it seems that the front panel acts as a shield for the main board. As you pull it away the noise increases, but if you pull away a shield you could expect something similar to happen. Why do you think that removing the cabinet's conductive paint would improve this situation? I'm probably missing something, but I'm not convinced these are related.
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I can't be sure, but looking at your last video it seems that the front panel acts as a shield for the main board. As you pull it away the noise increases, but if you pull away a shield you could expect something similar to happen. Why do you think that removing the cabinet's conductive paint would improve this situation? I'm probably missing something, but I'm not convinced these are related.
1. Conductive paint has cracked and can break off.
2. Each zone should be shielded/isolated one from another, i.e. PSU, DC/DC adapater, mainboar, from panel, etc... (See the DS2072 teardonw as good example). In the SDS7102 due to its iternal construction is very difficult to achieve this.
3. Do not forget the screen, I'm not willing to spend more money on the material needed to shield it properly.
I used a aluminum foil as a substitute using an external monitor.
"I can't be sure, but looking at your last video it seems that the front panel acts as a shield for the main board. As you pull it away the noise increases, but if you pull away a shield you could expect something similar to happen."
Yes, but this panel attenuating the field generated by the DC/DC behind it, in fact that is the predominant noise when removing it. However, the shielding (including the aluminum foil) not eliminates or attenuates the common mode noise "radiated" by the connector that joins the adapter board with the mainboard. For all this and the above exposed (1,2 and 3) I decided remove the conductive paint.
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Carrington,
I get your reasoning, specially item 2, which I think would be needed to control reflections, particularly where SMPS circuits are present. Is the front of your scope's cabinet, lettering, logos, OK after the removal process? I saw a powdery substance on your last images and couldn't tell if it was damage or just easily cleanable residue.
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Carrington,
I get your reasoning, specially item 2, which I think would be needed to control reflections, particularly where SMPS circuits are present. Is the front of your scope's cabinet, lettering, logos, OK after the removal process? I saw a powdery substance on your last images and couldn't tell if it was damage or just easily cleanable residue.
No damage, but takes a long time, the process is slow. The acid concentration is only 25%.
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I''ll do a trial to a test Nickel painted plastic, with a mix of HCL (conc. 7%) and H2O2 (conc. 35%).
From wikipedia read that the Nitric oxid is very well to Nickel dissolution, populate product about this is the "aqua forte".
It seems that yours shielding go away without problems...
TomC, the mainboard acts like as you said. I don't know if the exist a small flat ferite on the flat cable that joined the two boards could to be help.
The independent isolation of boards is very difficult to this. Agree with Carrington that "in the SDS7102 due to its iternal construction is very difficult to achieved this".
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I''ll do a trial to a test Nickel painted plastic, with a mix of HCL (conc. 7%) and H2O2 (conc. 35%).
:-+
After all night, the saturation of copper in the acid must be very high, if it gets into the pores of the plastic will be difficult to remove. So I think that is better change the acid when this becomes very green.
At the rear side:
- I believe that the off-white residue/color is due to paint solvent, I doubt that it can be eliminated. :(
- The greenish yellow should be residue/color of copper oxide, after another bath clean acid should look better.
At the front side:
- I can not see any damage.
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I''ll do a trial to a test Nickel painted plastic, with a mix of HCL (conc. 7%) and H2O2 (conc. 35%).
From wikipedia read that the Nitric oxid is very well to Nickel dissolution, populate product about this is the "aqua forte".
Good luck! :-+
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After all night, the saturation of copper in the acid must be very high, if it gets into the pores of the plastic will be difficult to remove. So I think that is better change the acid when this becomes very green.
At the rear side:
- I believe that the off-white residue/color is due to paint solvent, I doubt that it can be eliminated. :(
- The greenish yellow should be residue/color of copper oxide, after another bath clean acid should look better.
At the front side:
- I can not see any damage.
The results on the images look good! :-+
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Wow! Great work on removing that conductive paint! :-+
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Thanks. :)
The acid is for use in swimming pools (conc. 25-35%), and the H2O2 can be found in pharmacies (conc. 10%).
Lemon should be HCL (conc. 35%) and H2O2 (conc. 7%).
I will continue with the process along this week. :-/O
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Small update from me: After reinstalling the firmware several times, it seems that the drift of channels when scope is off is now gone. Also now it seems to be able to determine that there is nothing connected to probe end if autoset is pressed. I don't usually use this feature, so I don't know if that's something they added in a new firmware or nor, but I remember that this time last year, it couldn't detect if the probe was connected to BNC and the tip is floating.
Also now for some strange reason, I can detect the waveform of the main transformer of the PSU with a probe next to the PSU vents with back cover on. I think that this wasn't the case before, but I don't really remember holding the probe to the back of the PSU.
It seems that just as I fix one issue, two new appear.
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Also now for some strange reason, I can detect the waveform of the main transformer of the PSU with a probe next to the PSU vents with back cover on. I think that this wasn't the case before, but I don't really remember holding the probe to the back of the PSU.
This probably has always been there, from the front the z-plate shields must emissions from this transformer, but is open space from the back. I think it would be beneficial to reduce these emissions, they can easily re-radiate of other elements and eventually become CM noise. In my opinion, this was partially to blame for Lemon's and Carrington's negative results with the conductive paint. I'm planning on trying some noise control approaches for this transformer. A simple one that I'll probably try first is a belly strap.
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What does term "belly strap" mean in this context?
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A simple one that I'll probably try first is a belly strap.
Be careful with that.
What does term "belly strap" mean in this context?
See attachments.
http://www.righto.com/2012/11/teardown-of-mysterious-kms-4-port-usb.html (http://www.righto.com/2012/11/teardown-of-mysterious-kms-4-port-usb.html)
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Thanks a lot! It's clear to me now.
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I''ll do a trial to a test Nickel painted plastic, with a mix of HCL (conc. 7%) and H2O2 (conc. 35%).
From wikipedia read that the Nitric oxid is very well to Nickel dissolution, populate product about this is the "aqua forte".
...
I painted with Nickel spray a small plastic and I try to removed today by a mix of HCL (conc. 7%) and H2O2 (conc. 35%). This solution is usual for cooper removed from my diy pcb's.
Unfortunately, nothing! I leaved it 4 hours and nothing! Nickel seems not to react with this solution. Perhaps it needs to warm but it is very complex for now.
Now, I am looking about Nitric oxid.
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I painted with Nickel spray a small plastic and I try to removed today by a mix of HCL (conc. 7%) and H2O2 (conc. 35%). This solution is usual for cooper removed from my diy pcb's.
Unfortunately, nothing! I leaved it 4 hours and nothing! Nickel seems not to react with this solution. Perhaps it needs to warm but it is very complex for now.
Now, I am looking about Nitric oxid.
It should be the other way, I think, i.e. HCL (conc. 25-35%) and H2O2 (conc. 10%).
Where did you get the Nitric oxide?
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I didn't get nitric oxide, yet. I am looking for.
I found a super market product (tuboflo) that contains nitric oxide but contains and NaOH also.
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I didn't get nitric oxide, yet. I am looking for.
I found a super market product (tuboflo) that contains nitric oxide but contains and NaOH also.
Is something like this?
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There are tub.o.flo series, gel and powder.
The first used as is, the second needs water to act.
The powder serie has two versions, the one acts with cold water (blue versions) and contains Nitric oxide and NaOH, the other acts with hot water (red versions) and contains NaOH only.
If you read the instructions of the powder version (cold water), needs a lot of attention with the water...
(http://www.pulena.net/filestore/jpg/TUBOFLO.jpg)
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I have news about how to remove the Nickel Shield.
After, no success with blue tuboflo, I come back with the mix of HCL+H2O2. I make a fresh 37% HCL and a fresh 35% H2O2.
From the HCL(37%) I make a 14% solution (this done with warm water).
I left the front plastic case of osciloscope into this solution for 4-5 hours.
After that there is no clean complete but after drying I see that there is no any continuity of surface (I measure it with multimeter). Seems like to away the Nickel layer and still a paint lacquer light gray colour.
Photos I''ll upload later.
I tested it complete open (only with the front case) and noise decreased by 10mV.
The same period with the test, I had took some flat ferrites from farnell.
Before I had test the area of tft flat cable that joined with adapter board by the probe tip and I have seen some major noise over there. It was a mysterious combination noise of tft and psu TR1 transformer.
For that reason I decide to order two flat ferrites from Farnel, a FPC-31-12K 26mm KE Kitagawa flat ferrite and a SSC-33.5-20M 26mm KE Kitagawa flat ferrite (datasheet: http://www.farnell.com/datasheets/31877.pdf (http://www.farnell.com/datasheets/31877.pdf).
The FPC has better result to noise. With complete open oscilloscope (only front case) I came to 34-44mV (normal or peak) and 20-24mV (Average 16/100-200usec)
Finaly, it wasn't accident that Owon puts this ferrite to this area at the later oscilloscope versions.
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Hello, last time I was here this thread had like 50-60 pages, now it is 135!
Wanted to ask has anyone fixed their SDS 7102 noise problems? Did Owon make a new PSU board which was touted to be the route? Any other ideas?
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Hello, last time I was here this thread had like 50-60 pages, now it is 135!
Wanted to ask has anyone fixed their SDS 7102 noise problems? Did Owon make a new PSU board which was touted to be the route? Any other ideas?
Today there is new PSU and adapter board. (have been some time)
Also there is solutions for these manufacturing versions what show extra high ground RF noise.
It need also here remember that IF signal is clean in oscilloscope BNC input there have not been any noise issue related to this "noisy GND" issue.
Owon have extremely low noise front end. There is available lot of tests about it. Even with these "noisy GND" versions.
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Hello, last time I was here this thread had like 50-60 pages, now it is 135!
Wanted to ask has anyone fixed their SDS 7102 noise problems? Did Owon make a new PSU board which was touted to be the route? Any other ideas?
Today there is new PSU and adapter board. (have been some time)
Also there is solutions for these manufacturing versions what show extra high ground RF noise.
It need also here remember that IF signal is clean in oscilloscope BNC input there have not been any noise issue related to this "noisy GND" issue.
Owon have extremely low noise front end. There is available lot of tests about it. Even with these "noisy GND" versions.
Is it easy to get the new PSU/adapter board and fit it in? Where can I get it from?
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The new PSU & Adapter board that rf-loop said is the Adapter Ver. 3.2 or 3.3 (the only difference is a smd bypass capacitor) and the PSU with unkonwn mark that Owon produce after PSU PCB-T115-J Rev.3.
Owon sends a kit that including the new psu board and one smd capacitor (https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/msg257623/#msg257623 (https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/msg257623/#msg257623)), but this is OK if you have adapter version 3.2, if you had an older version than 3.2 you need a new adapter version or to modificate it.
For that the best solution is to communicate with your Owon dealer.
Here are the photos of these new boards: https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/msg273905/#msg273905 (https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/msg273905/#msg273905)
https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/msg274030/#msg274030 (https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/msg274030/#msg274030)
If you had the adapter version 3.2, there is no need to take the 3.3 version, you can put the smd alone.
With these boards and a flat ferrite to flat tft display cable, the noise decrease to 25-35mV (10X).
Member like rf-loop and Siri have presented some modifications to older adapters with success. Have these wonderfull projects to my mind, I had doing some trials to decrease my gnd-noise and I had success.
Look the following links.
PSU PCB-T113-J Rev.6 (through-hole components) : https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/?action=dlattach;attach=57753;image (https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/?action=dlattach;attach=57753;image)
Suggestion to PCB-T115-J rev4 PSU board = https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/msg276411/#msg276411 (https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/msg276411/#msg276411)
Adapter Version 3.0, first modifications = https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/msg271798/#msg271798 (https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/msg271798/#msg271798)
Adapter Version 3.0, last modifications = https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/msg290177/#msg290177 (https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/msg290177/#msg290177)
https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/msg289496/#msg289496 (https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/msg289496/#msg289496)
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The new PSU & Adapter board that rf-loop said is the Adapter Ver. 3.2 or 3.3 (the only difference is a smd bypass capacitor) and the PSU with unkonwn mark that Owon produce after PSU PCB-T115-J Rev.3.
Owon sends a kit that including the new psu board and one smd capacitor (https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/msg257623/#msg257623 (https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/msg257623/#msg257623)), but this is OK if you have adapter version 3.2, if you had an older version than 3.2 you need a new adapter version or to modificate it.
For that the best solution is to communicate with your Owon dealer.
Here are the photos of these new boards: https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/msg273905/#msg273905 (https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/msg273905/#msg273905)
https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/msg274030/#msg274030 (https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/msg274030/#msg274030)
If you had the adapter version 3.2, there is no need to take the 3.3 version, you can put the smd alone.
With these boards and a flat ferrite to flat tft display cable, the noise decrease to 25-35mV (10X).
Member like rf-loop and Siri have presented some modifications to older adapters with success. Have these wonderfull projects to my mind, I had doing some trials to decrease my gnd-noise and I had success.
Look the following links.
PSU PCB-T113-J Rev.6 (through-hole components) : https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/?action=dlattach;attach=57753;image (https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/?action=dlattach;attach=57753;image)
Suggestion to PCB-T115-J rev4 PSU board = https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/msg276411/#msg276411 (https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/msg276411/#msg276411)
Adapter Version 3.0, first modifications = https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/msg271798/#msg271798 (https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/msg271798/#msg271798)
Adapter Version 3.0, last modifications = https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/msg290177/#msg290177 (https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/msg290177/#msg290177)
https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/msg289496/#msg289496 (https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/msg289496/#msg289496)
OK, If I understand this right, there are many versions of the adapter boards, from 3.0, 3.2, 3.3 and if I have anything < 3.2 then I need a new adapter board from Owon?
If my adapter board is > 3.2 then all I need is to change a SMD capacitor?
And in addition I always have to use a ferrite choke to attach to the display cable (do Owon also send me the ferrite?)
Have I got it right?
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There are many adapter versions, I think older than 3.0.
Right, if you have adapter version 3.2 there is no need to change it to 3.3
When you have bought the SDS7102 or what serial number without 3 last digits have you?
Please do it this test and tell us how many mV: https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/msg255469/#msg255469 (https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/msg255469/#msg255469)
There isn't the flat ferrite in Owon kit. In early versions of Owon this ferrite including, there isn't to the older versions.
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There are many adapter versions, I think older than 3.0.
Right, if you have adapter version 3.2 there is no need to change it to 3.3
When you have bought the SDS7102 or what serial number without 3 last digits have you?
Please do it this test and tell us how many mV: https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/msg255469/#msg255469 (https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/msg255469/#msg255469)
There isn't the flat ferrite in Owon kit. In early versions of Owon this ferrite including, there isn't to the older versions.
My serial number is SDS71021211675 version 2.8.1
I did the test as per instructions and got 585mV !!!!
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Here is a picture:
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Here is a picture:
Oh my god. :o
"Owon have extremely low noise front end. There is available lot of tests about it. Even with these "noisy GND" versions."
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I think, if you care to look back, it was me that mentioned maybe a year ago, that my scope was "faulty".
These are extracts of my comms to the UK supplier :
Friday, 28 December 2012 5:09 pm
I believe the Owon sds-7102V may be defective : at low level signals there is a lot of noise, and the curve does not stand still on the screen. Is there a place in the UK that can perhaps repair it?
29 December 2012 2:19 pm
The problem is the scope has random "noise" which makes it almost impossible to view low voltage signals.
9 January 2013 7:53 am
Yes the problem still exists with the limit set to 20M.
11 January 2013 7:59 am
The problem is the same for both channels and I have tried 4 different probes. It is the same problem all the time.
24 January 2013 8:57 am
I have replied to you that there is a problem with the scope at low signal voltages. It affects both channels and I have tried 4 different probes. The problem is not with the probes, it is with the scope. You have sent me a lot of emails asking me all these questions, but you have not yet told me how you are proposing to repair or replace my scope.
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"Owon have extremely low noise front end. There is available lot of tests about it. Even with these "noisy GND" versions."
My original text:
It need also here remember that IF signal is clean in oscilloscope BNC input there have not been any noise issue related to this "noisy GND" issue.
Owon have extremely low noise front end. There is available lot of tests about it. Even with these "noisy GND" versions.
And I can stay behind these my word.
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"Owon have extremely low noise front end. There is available lot of tests about it. Even with these "noisy GND" versions."
My original text:
It need also here remember that IF signal is clean in oscilloscope BNC input there have not been any noise issue related to this "noisy GND" issue.
Owon have extremely low noise front end. There is available lot of tests about it. Even with these "noisy GND" versions.
And I can stay behind these my word.
Are you trying to see that I am doing something wrong? What do you mean by "if signal is clean ..." ? Are you saying that I am doing something to pollute the signal? If yes then please please show me how to "unpollute" it. I only want it to work after all :)
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"Owon have extremely low noise front end. There is available lot of tests about it. Even with these "noisy GND" versions."
My original text:
It need also here remember that IF signal is clean in oscilloscope BNC input there have not been any noise issue related to this "noisy GND" issue.
Owon have extremely low noise front end. There is available lot of tests about it. Even with these "noisy GND" versions.
And I can stay behind these my word.
Are you trying to see that I am doing something wrong? What do you mean by "if signal is clean ..." ? Are you saying that I am doing something to pollute the signal? If yes then please please show me how to "unpollute" it. I only want it to work after all :)
No, it was lightweight note to carrington about how to quote. ;)
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Here is a picture:
Welcome to the club! I have scope from same batch and it shows similar results!
My first advice to you, if you want to try to modify the PSU, is to change the MC34063A with one from a reputable manufacturer. I got some 15 K decrease in temperature just from that (but it could be that my MC is pretty problematic). Next, removing the current sense resistor for MC removed much of the noise. Another helpful step for me was to place a metal bar next to the PSU<->adapter cable and then place small SMD capacitors from each line to the bar and connect the bar to ground(I'll try to dig up link with images of that). With that, I came close to some 200 mV of noise with 150 MHz probes. Still the PSU noise remains.
There are some problems with adapter noise as well, but I haven't investigated the much, since I had numerous problems with the PSU (some of them made by me), so I can't tell much about that board. For example, on my PSU, in the main switch, one switch had contact resistance of around 100 ohms and the second had resistance of around 10 ohms, so I had to open the switch and work a little bit on the contacts themselves.
Also does anyone know how much the adapter board costs? I remember that Owon used to ask $50 for PSU, but I don't think anyone mentioned adapter board price.
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I have a suspicious that the psu of Akis is similar to AndrejaKo, very bad gnd_noise!
I have a suspicious that with this serial number, you must have an adapter version 3.0
Akis, can you open the oscilloscope gently?
There is a teardown video, how to dismantle the unit. Perhaps the upper gray button to open it with a strong pull it by pliers (put a cloth between pliers and button)
SDS Teardown (https://www.youtube.com/watch?v=Zct3Ircz6nY#)
My opinion if you have PSU board PCB-T115-J rev4 (https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/msg276171/#msg276171 (https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/msg276171/#msg276171)) is to buy a new one, than to modificate it.
If all the above happens, contact to your dealer and ask him to request warranty cover from Owon about this issue. Attach the captured gnd-noise that you have upload to us. Ask from him to coverage the psu and adapter board by warranty and you coverage the shipping cost.
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I have already contacted the dealer asking for one of these new boards/adapters/whatever and they asked me to send them my serial number SDS71021211675 and also they asked me to attach a picture with the problem, so I sent them the one I posted here plus rf-loop's instructions.
I do not want to open the scope just yet in case they decide to take the scope back and replace it with a new one. I presume the new models have very little noise, yes?
If it comes to repairing, I presume the Owon "kit" is better than trying to hack into the scope?
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In my experience, it's easier to just press the top power button and then carefully remove the back cover so that it slides over the button. I agree with trying to use warranty for this, if possible!
Insist on getting a scope from 2013. They should be much better than the 2012 version. Also on my scope, the main board had problems with turning on. Sometimes, it would freeze during boot. It could be that this is a bad batch.
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"Owon have extremely low noise front end. There is available lot of tests about it. Even with these "noisy GND" versions."
My original text:
It need also here remember that IF signal is clean in oscilloscope BNC input there have not been any noise issue related to this "noisy GND" issue.
Owon have extremely low noise front end. There is available lot of tests about it. Even with these "noisy GND" versions.
And I can stay behind these my word.
Are you trying to see that I am doing something wrong? What do you mean by "if signal is clean ..." ? Are you saying that I am doing something to pollute the signal? If yes then please please show me how to "unpollute" it. I only want it to work after all :)
No, it was lightweight note to carrington about how to quote. ;)
Sorry if I bothered you, not my intention, but don't worry, hereafter I don't omit anything. :-+
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I have already contacted the dealer asking for one of these new boards/adapters/whatever and they asked me to send them my serial number SDS71021211675 and also they asked me to attach a picture with the problem, so I sent them the one I posted here plus rf-loop's instructions.
I do not want to open the scope just yet in case they decide to take the scope back and replace it with a new one. I presume the new models have very little noise, yes?
If it comes to repairing, I presume the Owon "kit" is better than trying to hack into the scope?
This is the best that I wish to you!
The new versions are free from this noise_ground. Some members with new versions have measured a range of 25-40mV (10X) with full bundwidth.
The repairing with diy approach has its magic story but if you want a quickly and sure result, the psu and adapter change is must! Some dealers have start to coverage this issue by the warranty.
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So all this bullshit is because they used switched mode or buck converters which create tons of noise inside the scope? Could they not use some sort of linear technique (without the heat of course) ?
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Does anyone have old Owon Labview operation examples file? There used to be one on old Owon site, but now the link leads to SCPI instructions
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Does anyone have old Owon Labview operation examples file? There used to be one on old Owon site, but now the link leads to SCPI instructions
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Some pictures of the fixture I built to test the Owon PSU boards. The base was built from an old ATX PSU from which I retained the power SW, the AC connector and the fan. Inside the ATX PSU box there is a 5 ohm 100W resistor that along with the fan is used as the load for the 8.4V supply.
The first image shows the connectors. The power connector has an easy way to open the white wire to connect an ammeter. The battery connector is hooked up to two 4 ohm 25W resistors in series to provide an 8 ohm load that simulates charging the battery. There is also a 10 ohm 25W resistors with alligator clips that can be easily hooked up in parallel to the 8 ohm load. This will only be used to test the PSU's ability to switch to current mode when the output current reaches 3.75A. The connector that takes the place of the adapter board hooks up the switched 8.4V to the 5 ohm resistor inside, and the -7.6V to a 50 ohm 10W resistor on the back. It also connects the appropriate outputs to a green and a red LED. The AC trigger output is also connected to the terminal strip on back and easily available for scoping if necessary.
The second image shows the Owon PSU board installed in the stationary position. In this case, the ATX PSU case simulates the Z-plate for a more realistic environment when testing for common mode noise. In this image the 10 ohm 25W resistor is shown hooked up in parallel to the 8 ohm resistor.
The third image shows the Owon PSU installed in the movable position. This will be used when access to the printed circuit side is needed. In this image the white power wire has been opened and the ammeter is shown connected between the two ends. Because of the nature of PWM supplies, accurate current measurements can only be obtained with a true RMS instrument.
The fourth image shows the components mounted on the back of the ATX PSU.
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I see that your project goes well and very soon we have your first observation about this.
Simple and smart construction, bravo TomC :-+
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@Carrington: Thanks a lot!
@TomC
Great construction!
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So all this bullshit is because they used switched mode or buck converters which create tons of noise inside the scope? Could they not use some sort of linear technique (without the heat of course) ?
I don't know if they used switched mode psu because is less expensive or they want to avoid more temperature inside the scope, it has tight internal either.
Also, I don't know what do the others companies about this, but finally the major problem (for my opinion) wasn't the switched mode but the bad design. Today with the same internal topology inside (psu+adapter boards) the ground noise is low and acceptable.
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Does anyone have old Owon Labview operation examples file? There used to be one on old Owon site, but now the link leads to SCPI instructions
This seems to be still available but in a different place. Go to technical data and then click Application.
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Haven't been able to find a reliable, repetitive way to measure noise using the PSU test fixture. I'm thinking perhaps an LISN similar to the ones used to certify for EMI may help. May try to build one tomorrow.
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TomC noise varies each time to measure it? LISN could to be help you, as you says.
I found another link, here in the eevblog about SDS7102 that have some interesting information. The link is https://www.eevblog.com/forum/reviews/owon-sds7102-i-don%27t-believe-it!/ (https://www.eevblog.com/forum/reviews/owon-sds7102-i-don%27t-believe-it!/).
I summarized this thread to:
1) someone improved the noise spikes, just a very well cleaning of the mainboard and mainkeybord boards (many fingerprints on that (https://www.eevblog.com/forum/reviews/owon-sds7102-i-don%27t-believe-it!/msg142940/#msg142940)). I think mine these boards have also many of these fingerprints.
2) there is a talk about what is language of fw - they conclused that is building on OSGi framework (java) (https://www.eevblog.com/forum/reviews/owon-sds7102-i-don%27t-believe-it!/msg151244/#msg151244).
3) there is a suggested mod to psu (https://www.eevblog.com/forum/reviews/owon-sds7102-i-don%27t-believe-it!/msg151474/#msg151474) fom less battery draining but I don't understanding the solution (TomC, please look that)
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Does anyone have old Owon Labview operation examples file? There used to be one on old Owon site, but now the link leads to SCPI instructions
This seems to be still available but in a different place. Go to technical data and then click Application.
It's not there. The link which says it's the LabView file actually leads to SCPI file.
@lemon
I read that thread and after reading it carefully inspected my scope. The rotary encoder side of the main keyboard PCB was very clean on my scope, but its back side was dirty. There was some contamination of the main PCB as well and lots of it under the RF cans! I cleaned that up, but on my unit, it produced no visible results. On the other hand, it could be that my unit is too noisy for the results to be visible.
Also can someone here please try to access scope via network while the PC is wirelessly connected to the LAN? There are some issues discovered in the thread about Ethernet problems for Owon and I'd like to confirm if this is a bug somewhere or not.
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There is certainly an issue with the ethernet port which I will summarise here:
1) can ping over wireless but cannot download anything
2) cannot ping over homeplug devices, even though the Owon is connected straight to the router/hub
3) can ping and download only when the software is running on a PC which is directly connected to the LAN, ie no wireless and no homeplug
Number (2) maybe be a hint: when I connect my PC to the LAN through the homeplug device (the system using the electrical cables), it cannot ping or "see" the Owon - but just the Owon. I can ping and connect and use everything else in the house, including other PCs, TVs, Blue-Ray players, routers, wireless access points, printers, everything.
Observing how the oscilloscope software works, I have made another assumption : it may be that in the handshake/start/stop download, they have used simple "waits" rather than proper synchronisation protocols, and these "waits" work only when you are on a real ethernet cable with specific latency. But when you are over the wireless / homeplug, there is added latency that probably throws all those primitive "waits" off. Just an idea.
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TomC noise varies each time to measure it? LISN could to be help you, as you says.
The problem, I think, is that it's difficult to differentiate between conductive and radiated noise using the method of the long ground lead and the probe both connected to a common ground. I think this is further compounded by the open air environment. So the noise is different at different locations and also depends on the position of the ground lead and probe in respect to other components, connecting wires, etc. This will make it difficult to determine if a mod actually gives better results or not.
3) there is a suggested mod to psu (https://www.eevblog.com/forum/reviews/owon-sds7102-i-don%27t-believe-it!/msg151474/#msg151474) fom less battery draining but I don't understanding the solution (TomC, please look that)
I looked at the mod from muvideo, his comments are based on the PSU schematic in the Service Manual. He is proposing adding additional components that may be difficult to fit on the existing PSU board, but the idea seems sound otherwise. In my opinion, if battery drainage is a problem, a simpler to implement idea would be what rf-loop suggested, trying to find a substitute Standby switch which is DPST instead of SPST. This way you could use the extra switch to disconnect the battery.
If I had the battery option I probably wouldn't have this problem because I leave the scope on Standby all the time.
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You've right, if you can't to stabilize the variables you can't to determine if a mod actually gives better results or not. But I am sure something solution you'll find.
I looked the thread again and at the last message he says that have battery drainage (1/2) after two months. He had used an extra switch to positive before.
Finaly, I don't know if this mod is usefull becouse the Lipo battery has a drainage itself.
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Also can someone here please try to access scope via network while the PC is wirelessly connected to the LAN? There are some issues discovered in the thread about Ethernet problems for Owon and I'd like to confirm if this is a bug somewhere or not.
I tried it wirelessly from the laptop. It works as well as from the PC with a wired connection, which is not that great anyway. It's slow, freezes the scope if you do High Memory Depth with the Acquire length set to 10M, and the SCPI command line emits an error and freezes the scope. Other than that it limps along.
By the way, where is that thread at, I tried a search but came out empty.
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Also can someone here please try to access scope via network while the PC is wirelessly connected to the LAN? There are some issues discovered in the thread about Ethernet problems for Owon and I'd like to confirm if this is a bug somewhere or not.
I tried it wirelessly from the laptop. It works as well as from the PC with a wired connection, which is not that great anyway. It's slow, freezes the scope if you do High Memory Depth with the Acquire length set to 10M, and the SCPI command line emits an error and freezes the scope. Other than that it limps along.
By the way, where is that thread at, I tried a search but came out empty.
Here's the link https://www.eevblog.com/forum/testgear/owon-sds7102v-ethernet-port/ (https://www.eevblog.com/forum/testgear/owon-sds7102v-ethernet-port/)
My scope doesn't seem to respond to ARP at all, based on some tests I did. I'm in a bit of rush at the moment, but I'll do some more serious packet capturing next week and try to get to the bottom of this. I'm not sure how the scope works at all, if it's refusing to talk ARP.
I'm not sure what OS you're using, but on most popular ones, you can type arp -a in terminal and it should show ARP cache. Could you please try doing some work with the scope over network and report if its IP address shows up in ARP cache after working with it?
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My scope doesn't seem to respond to ARP at all, based on some tests I did. I'm in a bit of rush at the moment, but I'll do some more serious packet capturing next week and try to get to the bottom of this. I'm not sure how the scope works at all, if it's refusing to talk ARP.
I'm not sure what OS you're using, but on most popular ones, you can type arp -a in terminal and it should show ARP cache. Could you please try doing some work with the scope over network and report if its IP address shows up in ARP cache after working with it?
It's in the ARP cache. I tried this from the laptop through wireless to a Netgear router. While I was experimenting with this the wireless got knockout and I had to reboot the router. May be a coincidence that this happened while communicating with the Owon, but this doesn't happen often during regular use. Then again, I seldom use the LAN option to communicate with the Owon. The images show the Lan port settings on the Owon and the results of the test. The first Arp was done before communicating with the Owon.
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As we know, at the front of SDS case series there is an infrared "eye" but we haven't any information about this.
Finally it seems that this is an option that Owon never development or let it be as is.
If you look carefully the attachment photo from the "L" keyboard, it seems that there is the routing and position of an IrDA, with extra positions for the appropriate resistors and capacitor. This ends at the joined pins to main keyboard.
I don't know if the rest of main keyboard is ready for that (I see some IC's like 8-ch multi/demultiplexer and one dual binary counter), the mod it seems easy but the fw doesn't support this.
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Well, (infrared) remote controlled oscilloscope is a good idea. More useful than a touch screen. At LeCroy they use a detachable keyboard...
https://www.eevblog.com/forum/testgear/the-most-weird-and-funny-dso-metrix-mtx3000/msg221681/#msg221681 (https://www.eevblog.com/forum/testgear/the-most-weird-and-funny-dso-metrix-mtx3000/msg221681/#msg221681)
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Is there anything in the Owon at 150KHz? I was trying to work on a linear DC charger I am building, and saw this sawtooth curve at 150KHz - I could not understand where it was coming from.
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Mine is with low gnd_noise and I don't see anything at 150KHz (full or limited BW)
The fft_150KHz = is without any probes on scope, it is clear.
The fft_150KHz_with probe = with a probe on channel 1 to the air.
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I posted a possible schematic of the battery protection circuit here. (https://www.eevblog.com/forum/reviews/owon-sds7102-i-don't-believe-it!/msg299683/#msg299683)
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Some tests results for my old PSU obtained on the test fixture.
After looking at different alternatives for testing the PSU noise I opted for the setup shown on #1. The case of the power sw has the highest GND noise levels I could find and they are pretty consistent, so it's easy to determine if a modification has a beneficial effect. The CH2 probe's tip is isolated and is used to pick up the electric field at various locations. This signal is also used to trigger the scope while viewing the noise on CH1. As done before by other members, this allows pinpointing the source of specific noise bursts.
The worst noise makers are the -7.6 inductor (L2) and the anode connection to D5 (Q1's snubber). Of the two, L2 is the worst by far. The tests on this post are for the original L2 as well as several replacements that I tried. See #3a-3c for the tests for the original L2. Note that the original L2 measured 130µH.
I started my search for suitable replacements by looking at the OnSemi datasheet for the MC34063A. The attachment shows the inductor data on this datasheet. Notice that although the image shows an inductor similar to the one used by Owon, the note below the data table specifies a toroid. The next attachment shows the page on the Magnetics catalog with the data for the 55117 toroidal core.
I don't currently have one of these cores, but I had several toroids salvaged from PC PSUs that I decided to try, see #2. The medium sized toroid is very close to the size of the 55117 so I wound it with 28 turns of 22 AWG. As it turns out the permeability of this core must be very high because the inductance came to 3.2mH. I tried it anyway but the MC started to get very hot so I turned everything off, so no captures for this test.
I next tried the small toroid, even though the wire gauge is way smaller than 22. This coil worked surprisingly good, see #3a & #3b. The noise level dropped way down, the lowest level of all the tests I performed. The only negative was that the MC operates hotter than with the original coil. Original 49C, small toroid 57C. Also the coil gets a little hotter (60C). However, I left it operating for hours with no ill results. This small coil has 27 turns (34µH).
I also tried a large toroid installed as L2 on #2. It was 74 turns originally (254µH), and I shortened it to 40 turns (65µH), see #5a-5c. I also tried it at 27 turns (34µH) and 23 turns (28µH), see #6a-6d and #7a-7d. At 23 turns the noise results are almost as good as the small toroid, in addition, the MC operates at 51C and the coil at 46C, which is a lot cooler.
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That's are interesting results!
TomC, if I remember well the output of 8.4V used like input voltage to the MC34063. Then the IC3 works like an Voltage Inverting Converter.
From the datasheet, as well you said, this function needs 88uH (28 Turns of #22 AWG on Magnetic Inc 55117 Core), but Owon uses other value (because the core is differente).
Your result between 28-34uH are fine, but I think that we couldn't to extract a usefull result for what value needs there! It depends of Inductor core, isn't it?
I find this (http://www.onsemi.com/PowerSolutions/evalBoard.do?id=MC34063SMDINVEVB) evaluation board (Inverting function), At the BOM list the appropriate inductor is a SMD Coilcraft Power Inductor 100 ?H, 1.2 A, DO3316P-104_L
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Out of curiosity, how many voltages are provided by the PSU+adapter card, and has anyone thought, as an experiment, instead of trying to "improve" the switching mode supplies, to replace them with linear supplies, eg provided by the bench PSU and see what the traces look like? If the linear voltages produce good results, then we could try to design them on a PCB in the space of the existing casing.
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I think these are -7.6V, 5.5V, 3.3V. and a variable range for the LCD Backlight output.
Personaly, I have tried to supply the adapter board by a low noise PSU (Rigol DP832) but the output gnd_noise of scope was the same like Owon PSU (but mine psu was adapted and maybe it has a less noise than TomC PSU).
A russian member (BBAAHHOO) had done a lot of adaptation on psu+adapter with independent voltages and the total gnd_noise was very-very low (almost 12-15mV 10X set).
TomC, me, Carrington, AdrejaKo like to play with these circuit to improve for diy purposes.
Probably our talk about how to improve the noise for older psu and adapter versions, confuse other readers and they think that Owon SDS7102 has a ground noise problem.
It hasn't and I don't know if there is a significant reason to replace someone this latest version of Owon PSU+adapter, because the total gnd_noise is low (25-35mV, 10X set, full BW).
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Do you mean that those members used linear supplies to replace the SMPS ?
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Linear PSU had used the rf-loop but we haven't uploading results. He said that the results was fine.
BBAAHHOO, had strong adapted the psu+adapter with other add-on circuit and he gave to mainboard independend voltages (see his messages from page https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/1455/ (https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/1455/) and then).
Me had used linear PSU and supply the already mod my adapter, but as I said I have no any improvement, I don't try to remove and adapter board and give direct the appropriate voltages to mainboard (my scope was to examine a good linear psu vs Owon adapted PSU).
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then we could try to design them on a PCB in the space of the existing casing.
I think that's the catch. I don't know of a way that you could do linear without a power transformer, unless you are willing to accept enormous power losses. The other impediment, as I see it, is to make it a universal supply covering 100-250VAC mains. You would need to make at least the 8.4V part of the PSU conform to this. I think the size of the power transformer alone is the reason these supplies are SMPS nowadays.
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Your result between 28-34uH are fine, but I think that we couldn't to extract a usefull result for what value needs there! It depends of Inductor core, isn't it?
I find this (http://www.onsemi.com/PowerSolutions/evalBoard.do?id=MC34063SMDINVEVB) evaluation board (Inverting function), At the BOM list the appropriate inductor is a SMD Coilcraft Power Inductor 100 ?H, 1.2 A, DO3316P-104_L
That's right, the permeability and size of the core has a big influence. Unfortunately, with salvaged cores you may not be able to determine what the permeability is ahead of time, unless there is some numbering that you can find on the web. The cores that gave me good results were colored yellow, that may have some meaning as far as specs for the manufacturer.
The medium size core that turned out to have very high permeability had some numberings on it that didn't match anything on the web. I tried to reduce the inductance to around 100µH on this core but ended up with less than 5 turns. I tried it and the results were bad, so I gave up on it. Probably this type of core is useful on circuits where DC bias is an issue, but not for DC/DC converter coils.
With the yellow cores the GND noise on other areas, for example, the Z-plate substitute is very low, below 20mVpp. On the Power Sw cover the noise is much stronger, which makes it useful for testing. With a toroid for the -7.6V the dominant noise left is produced by the 8.V supply. It's just a little bit higher than what is left from the -7.6V with a toroid.
The Coilcraft SMD inductor doesn't seem to be a toroid, I don't know if the different design would help, but for now I'm thinking toroids are the better solution.
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TomC, me, Carrington, AdrejaKo like to play with these circuit to improve for diy purposes.
Probably our talk about how to improve the noise for older psu and adapter versions, confuse other readers and they think that Owon SDS7102 has a ground noise problem.
It hasn't and I don't know if there is a significant reason to replace someone this latest version of Owon PSU+adapter, because the total gnd_noise is low (25-35mV, 10X set, full BW).
Sorry to burst into this thread half arsed and off topic a little ....
So there is no noise problem on the newer models , and thus this negative is gone from the scope ?
I am left with pondering the reports of the scope being slow (WFm/s) , but not really fully understanding the implications of this , can anyone shed some light on this "slowness" ? (PM is fine if rather not OT the thread further)
Sorry again for my interruptions , it's the ubiquitous "looking for a new scope and out of the loop for some years" , that I am sure you guys are sick of :(
Gotta add this forum is great , wish I had found it ages ago , thanks to all of you guys for reigniting my interest in the art of not-releasing-magic-smoke :D
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Well newer units can reach triggering frequency of about 35 Hz, depending on scope settings, while old units go about 25 Hz. Do note that the scope is optimized for large memory sizes, so unlike most scopes, decreasing amount of used memory will not drastically increase speed.
How fast is that depends on what you want to use scope for. The story is actually extremely complicated, but I'll try to simplify it as much as I can.
A traditional oscilloscope works by connecting the voltage of input to Y axis on the CRT. The X axis is driven by timebase. It takes some time for the scope to draw waveform from right side of the screen to the left side and that's what you control with timebase knob. There's also some time which is needed for the beam to return back to the left side of the screen and during that time, you don't see the wave. This is called deadtime, if I remember correctly. On analog oscilloscopes, it's usually very short, so it isn't much of a problem.
On a traditional digital scope, instead of electron beam, we have an analog to digital converter. It takes some time for it to capture data and that time can be (more or less) thought of as the time during which an analog scope is drawing the wave on the screen. Once the ADC fills the memory, it stops capturing data and then the data is processed by the scope. Once the processing is finished, it's displayed on the screen. That time period can be thought of as the time which it takes for the analog scope to move the beam from the right side of the screen to the left.
The main difference is that the time it takes for DSO to "re-arm" is much longer than on a CRO. Let's calculate how much time new SDS7102 would cover. I mentioned that it has around 35 waveform updates per second. I'm using 10 Msample memory and timebase of 500 microseconds. I think that this will give me greatest time coverage at highest sample rate. When I press single-shot button, I see that the scope has 10 ms worth of data in memory. So if it updates 35 times per second, and each update gets 10 ms, we have coverage of 350 ms for each second. That means that in each second, there are 650 ms during which the scope is effectively blind.
The result is that should the effect you're looking for happen in the part of the second which is in those 650 ms, you won't see it on your scope at all. It may take quite some time to actually catch the abnormality you may be looking for, if it lasts for a short amount of time.
What you can do to mitigate the issue is first to try to set triggering on the scope in such way that the scope triggers on the abnormality and not on something else. It may, however, be very difficult to set the trigger in such way that you catch the glitch, especially if you don't know if the glitch exists in the first place and how it looks like. Even if you know that the glitch is there, depending on the glitch, it may take hours or maybe even days until the scope discovers it.
Second option might be useful if you're looking for slow changes on the signal. You could lower the sample rate so that there is more time between each individual sample. This way, you're changing the coverage of the time. Instead of having short groups of tightly packed samples, you now have longer groups of samples, but there's some extra time between each individual sample. For example, using sample rate of 2.5 Msamples per second and 10 Msamples memory, I managed to capture two seconds worth of data on my scope. When I "zoom in", that is to say increase the time-base of the scope when looking at captured data, scope stops providing interpolated signal at time base of 200 ns and then I can see that there are exactly 200 ns between each sample. If the glitch happened somewhere in that period of time, you won't see it.
The above is the reason why we today have scopes that cost a much as a new truck or tractor. High performance scopes have many more updates per second and they have advanced display modes that work by doing statistical analysis of the data and then provide results on screen, since it's more or less impossible to actually update the screen as quickly as the scope captures data. They still have some dead time, which is basically inherent in digital scopes, but the effect is greatly reduced.
This all leaves us with the question of what you want to use the scope for. If you need to catch some elusive, short glitches, then this is not a scope for you. If you don't, then I don't know what to say to you except that you'll need to help us help you.
I myself didn't have any problems with dead time of this scope so far, but on the other hand, I wasn't catching any strange glitches. My main uses of the scope are to debug digital logic. The FFT feature proved itself very useful for tuning radio scales as well.
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Linear PSU had used the rf-loop but we haven't uploading results. He said that the results was fine.
BBAAHHOO, had strong adapted the psu+adapter with other add-on circuit and he gave to mainboard independend voltages (see his messages from page https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/1455/ (https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/1455/) and then).
Me had used linear PSU and supply the already mod my adapter, but as I said I have no any improvement, I don't try to remove and adapter board and give direct the appropriate voltages to mainboard (my scope was to examine a good linear psu vs Owon adapted PSU).
I did try to power up the scope using a linear PSU, but it seems I was having some regulation problems with the PSU. I set it to 8.4 V, connected it instead of battery, but once I powered up the scope, voltage dropped down to around 5 V and scope kept pulling about 1 A. I was unable to increase the voltage because for some reason the operation voltage potentiometer of my 2.3 A home made PSU produced no results. It's the first time something like this happened. The scope keeps drawing power, but seems to be doing nothing in that mode. It could be a coincidence, but after each experiment like that, scope needed auto-calibration in order to give sane measurement results again.
Unfortunately, I won't have enough time for at least one more week to actually troubleshoot the PSU, since the semester just started here.
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I am left with pondering the reports of the scope being slow (WFm/s) , but not really fully understanding the implications of this , can anyone shed some light on this "slowness" ? (PM is fine if rather not OT the thread further)
To add a little to AndrejaKo's explanation, if the glitch is periodical and doesn't happen to be perfectly synchronized with the scope's trigger so that it constantly falls in the blind time, it will eventually show up on the visible time. It may be brief depending on the conditions, but you can enhance the chances of seeing it with the scope's persistence feature.
To help you make a decision, it may be useful to first analyze what you plan to use the scope for, at least most of the time. I think that between that and your budget you can get a better idea of what the best choice is for your individual case. Some sample questions to ask yourself: Do I plan to often use the scope to catch glitches? What's the highest frequencies I plan to view? Do I need to capture large amounts of data? etc.
Don't hesitate to ask questions! You'll find that most members of this forum don't mind to offer a helping hand! :)
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Linear PSU had used the rf-loop but we haven't uploading results. He said that the results was fine.
BBAAHHOO, had strong adapted the psu+adapter with other add-on circuit and he gave to mainboard independend voltages (see his messages from page https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/1455/ (https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/1455/) and then).
Me had used linear PSU and supply the already mod my adapter, but as I said I have no any improvement, I don't try to remove and adapter board and give direct the appropriate voltages to mainboard (my scope was to examine a good linear psu vs Owon adapted PSU).
I did try to power up the scope using a linear PSU, but it seems I was having some regulation problems with the PSU. I set it to 8.4 V, connected it instead of battery, but once I powered up the scope, voltage dropped down to around 5 V and scope kept pulling about 1 A. I was unable to increase the voltage because for some reason the operation voltage potentiometer of my 2.3 A home made PSU produced no results. It's the first time something like this happened. The scope keeps drawing power, but seems to be doing nothing in that mode. It could be a coincidence, but after each experiment like that, scope needed auto-calibration in order to give sane measurement results again.
Unfortunately, I won't have enough time for at least one more week to actually troubleshoot the PSU, since the semester just started here.
If I understand it right you tried to replace the battery with a bench PSU at 8.4V ? What would that achieve? The battery produces good, clean voltage anyway. The fact that your PSU stopped at 5V/1A could be because it uses a "foldback" current limiting ?
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I decided to use the small toroidal core for L2. Since I wasn't happy with the coil's 60C temperature I removed the original winding wire which was an extremely thin gauge and rewinded it with 24 AWG. I could only fit 24 turns of this wire in a single layer so I went with that. The inductance at 24 turns measured 27µH. The results are as good or better than with the original wire, see #1a-1d. In addition, the temperature of the MC is now 55C and the coil's 54C. So I think I'm done with noise reduction for the -7.6V, at least until I see if I like the results when I install the PSU in the scope.
For those of you that may want to try this mod, I was able to identify the core that I'm using and it's available at least from one source on the internet. These cores appear to be very common, so I wouldn't be surprised if some of you have one someplace in the junk box. It's a T44-26 iron powder core and its permeability is 75, see the attached photo and datasheet. It is available from the following source:http://powermagnetics.co.uk/pace-components/micrometals-iron-powder-cores/all-iron-powder-cores/t-44-26-micrometals-iron-powder-toroid (http://powermagnetics.co.uk/pace-components/micrometals-iron-powder-cores/all-iron-powder-cores/t-44-26-micrometals-iron-powder-toroid)
So now I plan to move on to the 8.4V. Surprisingly, although the near field of D5 is extremely strong, it doesn't translate into a large amount of GND noise as it was the case with L2, see #2a-2d. However, I'm going to see if it's possible to reduce this field somewhat, hoping that this will further reduce the GND noise.
Attachments #3a-4c show what the GND noise looks like with CH1 connected to the pseudo Z-plate instead of the Pwr Sw cover. As I mentioned on a previous post the noise is very low. However, although when L2 is the trigger there is no noticeable disturbance, there is some on the captures where D5 is the trigger. #5 is just showing the GND noise the way we usually measure it when the PSU is installed on the scope. I'm hoping that it stays that low when I install this PSU in my scope, but realistically, the environment and the noise generated by the adapter board will make it different.
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Do you know the current drawn out of the -7.6V line? (and out of the other voltages?)
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I think that the answers at your question is here (https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/msg294947/#msg294947):
I done a test with independent main psu.
For this reason I used a Rigol DP832 Triple Output PSU. This psu has a low noise threshold (3.5mVp-p)
I gave it a +8.4V/2.5A and -7.6V/0.5A power supply to adapter board.
From what I saw, the ampere consumption doesn't bigger than 1.43A with 0% backlight until 1.55 with 100% backlight for 8.4V.
The -7.6V has stable ampere consumption of 0.160A
....
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TomC, very useful link for magnetic core.
I'll wait for your results on total gnd_noise. I am very curious if the total gnd_noise after these mods on psu will better from decoupling capacitors solution of the original new psu board or what is going to be if you combined the two solutions.
Andrejako, I think that your problem with the 8.4V was the limited supply ampere of your psu . For what I have seen it uses 1.6A max. approximately.
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If I understand it right you tried to replace the battery with a bench PSU at 8.4V ? What would that achieve? The battery produces good, clean voltage anyway. The fact that your PSU stopped at 5V/1A could be because it uses a "foldback" current limiting ?
Well the goal was to avoid having to make pauses for battery recharge. I wanted to first fix noise issues with the MC34063A and the adapter board and after that proceed to look for issues with the primary side of the PSU, if there are any. On my particular PSU, the MC34063A and circuit supporting it are currently the greatest single source of noise and they make it difficult for me to inspect other noise sources inside the scope. If I use the linear PSU to provide external power, I can also use battery for the negative voltage and have very long run-times with such setup, because the current draw on the negative voltage rail is very low.
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Do you know the current drawn out of the -7.6V line? (and out of the other voltages?)
In addition, when the battery is charging, the 8.4V is designed to supply up to 3.75A, at which point it goes into current regulation rather than voltage regulation.
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That's right, I had forgotten this! :-+
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Bad news! :--
While probing with my not so well insulated probe I touched the part of the ground barrel that was exposed to Q1's heatsink. That connected GND-C and GND-A, something that I warned was a No-No on a previous post. |O
As expected, BOOM! :palm:
Preliminary check shows that IC1 (Richtek R7731A), Q1, and R5-R5C are fried. LF1 boiled and smoked but still has continuity, however it may have an internal short on one or both of the coils. There may be other damage that I haven't uncovered yet.
So I don't know how long it will take me to repair this thing, it will depend largely on the availability of the fried parts, specially the Richtek IC.
Edit: LF1 is fried too, internal shorts, reads low inductance.
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Oh no! :palm:
It remembers me, my "boom" when I examined the bloody Richtek R7731N.
You have a lot of damages, unfortunately. In my situation the damage was to Ricthek, R9, Q1, NTC and I changed preventive the two optocouplers PH1/2.
I don't know how easy you find the R7731a, this is more easy than R7731n but I don't know how you find the LF1 without technical characteristics.
As you know, I am waiting the new boards from Owon.
If you couldn't find the characteristics of LF1, I can to remove the old LF1 and measure it to the points that you are interesting.
Also I must look to my small lab, how many trials R7731a I have, to send you one if you can't find it..
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You are lucky that Owon are sending you new boards. In my case I am still waiting for the UK dealer to "authorise" my claim. I believe it is Chinese New Year however so maybe that's why I have not heard back from them.
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Bad news! :--
While probing with my not so well insulated probe I touched the part of the ground barrel that was exposed to Q1's heatsink. That connected GND-C and GND-A, something that I warned was a No-No on a previous post. |O
As expected, BOOM! :palm:
Preliminary check shows that IC1 (Richtek R7731A), Q1, and R5-R5C are fried. LF1 boiled and smoked but still has continuity, however it may have an internal short on one or both of the coils. There may be other damage that I haven't uncovered yet.
So I don't know how long it will take me to repair this thing, it will depend largely on the availability of the fried parts, specially the Richtek IC.
Edit: LF1 is fried too, internal shorts, reads low inductance.
Oh mate. No! Too bad! :-BROKE
My congratulations for the good result that you had obtained with L2. :-+
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After 72h per cover on acid:
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Thanks guys!
I asked Richtek for samples, but I don't have a company, so will see what they say!
Lemon, thanks for the offer, I may have to take you up on it!
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You are lucky that Owon are sending you new boards. In my case I am still waiting for the UK dealer to "authorise" my claim. I believe it is Chinese New Year however so maybe that's why I have not heard back from them.
I think that Chinese New Year was February 2013, not now.
If you see that for 15 days you haven't any respond from your dealer, send another one email and if there is no any lucky with him, send to Owon technical department your request and your situation with your dealer.
After 72h per cover on acid:
I am tired to mine, a lot of litres of acid = a lot of money.
As I told you, I have no any continuity on shielding surface now and I am perfect with a very low gnd_noise.
As you can see, I have open a new thread Comparison of oscilloscopes ground noise (https://www.eevblog.com/forum/testgear/comparison-of-oscilloscopes-ground-noise/), urging others members to upload their oscilloscope measurement.
There was no any great participation in that discussion and as you can see, a member reported that with this method we can not be exported reliable results btw different oscilloscopes, while another member suggested instead of using the probe to use a BNC shorting cap directly on the input connector.
The interesting was the uploaded captures from a Rigol - probably a DS1052 or something similar - with the cheap Chinese Probe (like ours) the Rigol was at 80mV about and with expensive Tektronics Probe it was 20mV about.
Mine after all modifications to this test with the BNC Shorting Cap has 12-16mV (10X) on CH1 and 14-18mV on CH2.
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As you can see, I have open a new thread Comparison of oscilloscopes ground noise (https://www.eevblog.com/forum/testgear/comparison-of-oscilloscopes-ground-noise/), urging others members to upload their oscilloscope measurement.
There was no any great participation in that discussion and as you can see, a member reported that with this method we can not be exported reliable results btw different oscilloscopes, while another member suggested instead of using the probe to use a BNC shorting cap directly on the input connector.
The interesting was the uploaded captures from a Rigol - probably a DS1052 or something similar - with the cheap Chinese Probe (like ours) the Rigol was at 80mV about and with expensive Tektronics Probe it was 20mV about.
Mine after all modifications to this test with the BNC Shorting Cap has 12-16mV (10X) on CH1 and 14-18mV on CH2.
I can see where the method that we've been using can give unreliable results, but using a shorting cap will not show the GND noise produced by the Owon, it will basically just show the baseline noise plus a minimal amount of GND noise produced by the subtle unbalance of the shorting cap connections.
So even with the knowledge that external interference can skew the traditional GND noise test that we've been doing, I believe that the results more truly reflect the usability of our Owon scopes when it comes to viewing low level signals. We have always advocated to do the test in an environment that minimizes outside interference, however, excluding the interference from, for example, strong FM radio stations, would require more Draconian measures, like for example, a Faraday cage.
That is unpractical for most of us. Perhaps a more subtle approach would be to advocate using ferrites on the probe cables of our cheap Owon probes to make them function more like expensive Tek probes. This would minimize the antenna effect of the probe cable and is much less of a Draconian measure as opposed to using a Faraday cage.
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Hello everyone. I see my record of 12 ... 20mV still has not mastered :P Although I can `t do it myself yet s top ... Interference from the LCD screen is not getting smaller ... :-//
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Hello everyone. I see my record of 12 ... 20mV still has not mastered :P Although I can `t do it myself yet s top ... Interference from the LCD screen is not getting smaller ... :-//
In my opinion is worse interference in the LCD/Power connector.
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Hello everyone. I see my record of 12 ... 20mV still has not mastered :P Although I can `t do it myself yet s top ... Interference from the LCD screen is not getting smaller ... :-//
Please, remember me which version of adapter you have? If you have the adapter version 3.0 we have very good noise result from the LCD Backlight Circuit (look here (https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/msg290177/#msg290177)), but the tft display has no any shielding and radiates everywhere...
You are still the Lord of Noise!
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Here is my version of the adapter. LCD Backlight no noise :)
(http://)
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Hi! Just wanted to contribute to discussion about Owons.
I read a lot of bad issues with SDS series, sometimes they just don't work at all. But anyway I bought SDS5032E for education purposes and it is absolutely fine, everything works great, calibration is fine, have nothing bad to say about it for 200$.
So, if you wanna cheap scope - quite good I think. Although you always can run into broken one, but don't be so upset, usually good sellers from e-bay accept refunding.
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That is unpractical for most of us. Perhaps a more subtle approach would be to advocate using ferrites on the probe cables of our cheap Owon probes to make them function more like expensive Tek probes. This would minimize the antenna effect of the probe cable and is much less of a Draconian measure as opposed to using a Faraday cage.
I have bought more expensive probes plus my Alanogue Bechman Industrial's probes and they all produce the same shitty results. The problems are not with the probes.
As many of you have seen when I started this thread a year ago ( I think I was the first to complain that the scope was defective ) , I am not trying to view minute signals, to the contrary the Owon hits trouble with signals as large as +/-100mV or much greater. As the scope has been sold with a 3 year warranty, I fail to see what kind of warranty this is that fails to recognise the severe fault but instead asks the users to either "grin and bear it" or replace some adapter cards that cost $50 (or was it more) and would surely invalidate the warranty once you open and hack inside the scope!
In this case I believe that since there is a demonstrable problem, Owon should be recalling the affected scopes and repairing them free of charge to the user. There must be laws in the US they are breaking by either not honouring the warranty or by asking users to do their own repairs and have to pay for it.
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That is unpractical for most of us. Perhaps a more subtle approach would be to advocate using ferrites on the probe cables of our cheap Owon probes to make them function more like expensive Tek probes. This would minimize the antenna effect of the probe cable and is much less of a Draconian measure as opposed to using a Faraday cage.
I have bought more expensive probes plus my Alanogue Bechman Industrial's probes and they all produce the same shitty results. The problems are not with the probes.
As many of you have seen when I started this thread a year ago ( I think I was the first to complain that the scope was defective ) , I am not trying to view minute signals, to the contrary the Owon hits trouble with signals as large as +/-100mV or much greater. As the scope has been sold with a 3 year warranty, I fail to see what kind of warranty this is that fails to recognise the severe fault but instead asks the users to either "grin and bear it" or replace some adapter cards that cost $50 (or was it more) and would surely invalidate the warranty once you open and hack inside the scope!
In this case I believe that since there is a demonstrable problem, Owon should be recalling the affected scopes and repairing them free of charge to the user. There must be laws in the US they are breaking by either not honouring the warranty or by asking users to do their own repairs and have to pay for it.
I think you'll find agreement from many of the members that frequent this thread for must of what you say here!
The suggestion about the ferrites on the probe cables improves the immunity to outside interference, but doesn't do much in regards to the Owon's conductive GND noise. Neither would more expensive probes.
So far Owon hasn't acknowledged the GND noise problem as something covered under their 3 year warranty. The excuse has to do with the fact that the problem is associated with the use of long ground leads, but doesn't seem to affect operation when the scope is connected to the signal source by more noise proof methods, for example the short ground clip, or a scope probe test point.
You'll find that there is extensive disagreement with this position among our members. I for one feel that although GND noise caused by external sources is not Owon's problem, it's a different matter when the GND noise comes from the Owon itself as is the case here, even if it's only associated with the use of long ground leads.
However, there isn't much that we can do about it other than keep complaining or try to mitigate the problem ourselves. As far as laws are concerned, I think the facts of the case could be difficult and expensive to prove, and the outcome of fair restitution would be difficult to achieve.
In the meantime, Owon seems to have corrected the problem as per reports of new customers since June 2013. So the problem still persists only for users with older units that haven't upgraded to the newer boards.
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Hi everyone, i bought SDS7102V scope few days ago and i have question about it's FFT function.
I put DC signal from battery in one channel and measurement says voltage is 8.4V. When i turn FFT i can see big spike at 0Hz but it is not 8.4V, it is about 11.6V.
Does it need to be 8.4V??
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Hi everyone, i bought SDS7102V scope few days ago and i have question about it's FFT function.
I put DC signal from battery in one channel and measurement says voltage is 8.4V. When i turn FFT i can see big spike at 0Hz but it is not 8.4V, it is about 11.6V.
Does it need to be 8.4V??
As far as I know this initial spike is meaningless and always occurs regardless of where the probe is connected.
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Hi everyone, i bought SDS7102V scope few days ago and i have question about it's FFT function.
I put DC signal from battery in one channel and measurement says voltage is 8.4V. When i turn FFT i can see big spike at 0Hz but it is not 8.4V, it is about 11.6V.
Does it need to be 8.4V??
As far as I know this initial spike is meaningless and always occurs regardless of where the probe is connected.
Are you sure??
What the others think?
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I don't have the manual with me right now, but I think that explicitly says to run FFT on AC mode only and to expect issues with DC mode FFT. That would make it impossible to do DC FFT, so battery results can't be relied upon.
Here's a quote from the manual:"DC component or offset can cause incorrect magnitude values of FFT waveform. To
minimize the DC component, choose AC Coupling on the source signal." I'm not sure what they expect us to do when DC component is needed.
Also what are exact settings on your scope? I'd like to try to reproduce the behavior. I'll need trigger level and type, timebase, memory length, voltage range, as well as the actual FFT settings.
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Hi everyone, i bought SDS7102V scope few days ago and i have question about it's FFT function.
I put DC signal from battery in one channel and measurement says voltage is 8.4V. When i turn FFT i can see big spike at 0Hz but it is not 8.4V, it is about 11.6V.
Does it need to be 8.4V??
As far as I know this initial spike is meaningless and always occurs regardless of where the probe is connected.
Are you sure??
What the others think?
Connect CH1 to GND and run FFT. What do you see?
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@AndrejaKo
I just found it in manual. And the point is in AC coupling :)
Settings on the scope are:
Trigger: single, AC, rising edge, Auto
Time base: irrelevant
Memory: 10M
Voltage range: 5V or 2V
FFT window: irrelevant
Format: Vrms
X1
@TomC
When i connect CH1 (AC coupl.) to scope GND i get this:
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@AndrejaKo
I just found it in manual. And the point is in AC coupling :)
Settings on the scope are:
Trigger: single, AC, rising edge, Auto
Time base: irrelevant
Memory: 10M
Voltage range: 5V or 2V
FFT window: irrelevant
Format: Vrms
X1
@TomC
When i connect CH1 (AC coupl.) to scope GND i get this:
OK, for that test I believe you had CH1's trace on the center line. Now try setting the CH1 trace two divisions below or above the center line, coupling AC or DC shouldn't matter. Go to FFT and show us what you see. If your scope works the same as mine you should see that initial spike.
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Yes i see 0Hz spike, it is wierd..... i think red marker (1) on the left of the screen should be referent not center of the screen, but it is not big problem, before doing FFT i just need to put CH to the center. Am I right?
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Hi, all. Who knows, if I buy a chinese version, for example, http://item.taobao.com/item.htm?id=22075116206 (http://item.taobao.com/item.htm?id=22075116206), is it possible to somehow set the English there?
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Hi, all. Who knows, if I buy a chinese version, for example, http://item.taobao.com/item.htm?id=22075116206 (http://item.taobao.com/item.htm?id=22075116206), is it possible to somehow set the English there?
You can select eng language, so there is no problem.
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In owon tech support say, that in this chinese version no english language and they do not upgrade to english. can someone else has already bought a version like as the link above
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I don't have any personal experience with this, but I know that one user did buy Chinese version and that it had no English option. I also know that he did manage to upgrade from Chinese to export version via software, but he had to pay Owon some amount of money for the firmware. If I remember correctly, the story is somewhere inside of this thread.
I think that the user was sold Chinese version with a claim from Owon that it does support English and that's the reason why they allowed him to upgrade, but I'm not sure. That was few years ago, back when SDS was new.
Also I think that the SDS for Chinese market has a different prefix. I think its EDS-C for domestic version of SDS, but again I'm not sure that all scopes marked SDS are the export version.
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Yes i see 0Hz spike, it is wierd..... i think red marker (1) on the left of the screen should be referent not center of the screen, but it is not big problem, before doing FFT i just need to put CH to the center. Am I right?
Myself, I either do that or ignore the spike.
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New adapter board version. (not for older scopes)
Older scopes can use V3.3 adapter latest upgraded versions.
But overall this V4.4 tell that Owon have done "hard work" and they have take this case really seriously. But they have talked less and worked more.
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They changed all topology, routing and IC's, completely.
It is interesting why they don't keep the compatibility with the older versions. Maybe have changed and z-plate, rf-loop?
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New adapter board version. (not for older scopes)
Older scopes can use V3.3 adapter latest upgraded versions.
But overall this V4.4 tell that Owon have done "hard work" and they have take this case really seriously. But they have talked less and worked more.
Is this in production? Or is this preliminary info you got?
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New adapter board version. (not for older scopes)
Older scopes can use V3.3 adapter latest upgraded versions.
But overall this V4.4 tell that Owon have done "hard work" and they have take this case really seriously. But they have talked less and worked more.
Is this in production? Or is this preliminary info you got?
In normal production.
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They changed all topology, routing and IC's, completely.
It is interesting why they don't keep the compatibility with the older versions. Maybe have changed and z-plate, rf-loop?
Afaik it is functionally compatible, but TFT data cable is small amount too short in older models for this.
I have not time now to check if it need small mod for Z-plate corner or if can not?
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Good news! :-+
I just received R7731A samples from Richtek. Very nice of them to provide samples even though I explained that this wasn't for a new project, but for an existing PSU with a defective R7731A which I couldn't obtain locally.
I can get the MOSFET and the SMD resistors from Digi-Key, which I'm going to order soon.
The only remaining problem is the Common Mode Choke (LF1). I measured it's inductance in circuit in the past at it was 75mH. After I took it of the PCB, one side measured 100mH and the other less than 1mH. However, the ohms measurements proved that both sides have been damaged. I can't find a replacement of either value (75mH or 100mH) that will fit in the existing PC board holes.
So I took it apart to see if I could rewind it. It has 161 turns per coil, and the wire is 160" long. With it unwound the wire measures about 2.5 ohms (while it still was in the coil both sides measured quite a bit less than this due to internal shorts). The gauge of the wire seems to be Metric 2.0. The closest thing I have is AWG 30 which is thicker, about 1.5 ohms for 160". So I'm considering using this even though I'll probably end up with quite a bit less inductance. The only other alternative that I have so far is to use a toroidal choke salvaged from a PC PSU. It fits in the space available but has different inductance (about 1mH).
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Regarding my noise problem(s) Owon China have replied to me saying
1) there is a new "board" that costs $10 + $50 for shipping....
2) Meantime,kindly noted the new board only can reduce noise.
Can someone please explain to me?
(1) I thought that I need to replace two boards, something called the "PSU" board and another called the "adapter" board. Why are they talking only about one board?
(2) Why are they saying "only can reduced noise" ? Do they mean "cannot eliminate noise" ?
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Good news! :-+
I just received R7731A samples from Richtek. Very nice of them to provide samples even though I explained that this wasn't for a new project, but for an existing PSU with a defective R7731A which I couldn't obtain locally.
I can get the MOSFET and the SMD resistors from Digi-Key, which I'm going to order soon.
The only remaining problem is the Common Mode Choke (LF1). I measured it's inductance in circuit in the past at it was 75mH. After I took it of the PCB, one side measured 100mH and the other less than 1mH. However, the ohms measurements proved that both sides have been damaged. I can't find a replacement of either value (75mH or 100mH) that will fit in the existing PC board holes.
So I took it apart to see if I could rewind it. It has 161 turns per coil, and the wire is 160" long. With it unwound the wire measures about 2.5 ohms (while it still was in the coil both sides measured quite a bit less than this due to internal shorts). The gauge of the wire seems to be Metric 2.0. The closest thing I have is AWG 30 which is thicker, about 1.5 ohms for 160". So I'm considering using this even though I'll probably end up with quite a bit less inductance. The only other alternative that I have so far is to use a toroidal choke salvaged from a PC PSU. It fits in the space available but has different inductance (about 1mH).
Richtek USA has very good support, they provide samples easy. Can you see what marks has?
I don't know what kind is LF1, but you have measured 75mH at your schematics and the Owon's service schematic says 10mH!
Have you looking there?:http://gr.mouser.com/search/refine.aspx?Ntk=P_MarCom&Ntt=120657723 (http://gr.mouser.com/search/refine.aspx?Ntk=P_MarCom&Ntt=120657723)
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Regarding my noise problem(s) Owon China have replied to me saying
1) there is a new "board" that costs $10 + $50 for shipping....
2) Meantime,kindly noted the new board only can reduce noise.
Can someone please explain to me?
(1) I thought that I need to replace two boards, something called the "PSU" board and another called the "adapter" board. Why are they talking only about one board?
(2) Why are they saying "only can reduced noise" ? Do they mean "cannot eliminate noise" ?
Probably, they meant the PSU board but you must to clear it before.
Can you remember me, have you open the scope before? If yes, what psu and adapter versions have you?
If you don't know what kind of version you have, it is very difficult to take right decision for what to do.
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OK so I need to open up the scope and read two version numbers, adapter board and PSU?
My scope serial number is SDS71021211675 - I bought it in summer 2012 - I presume it has the "bad" PSU and adapter board. I am going to open it now.
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Regarding my noise problem(s) Owon China have replied to me saying
1) there is a new "board" that costs $10 + $50 for shipping....
2) Meantime,kindly noted the new board only can reduce noise.
Can someone please explain to me?
(1) I thought that I need to replace two boards, something called the "PSU" board and another called the "adapter" board. Why are they talking only about one board?
(2) Why are they saying "only can reduced noise" ? Do they mean "cannot eliminate noise" ?
Probably, they meant the PSU board but you must to clear it before.
Can you remember me, have you open the scope before? If yes, what psu and adapter versions have you?
If you don't know what kind of version you have, it is very difficult to take right decision for what to do.
It reduce noise, it do not remove all noise. No one can remove all noise.
I will recommend change both, result is better.
PSU (new version have some amount less noise)
Adapter board version V3.3 and latest sub version. Then note: if you do not have right soldering tools: Ask TFT backlight (it have two pin but 4 point surface mount) connector is already assembled on the board!
(most new V4.4 adapter board do not fit directly to older versions.)
(psu is not expensive and with same shipping price I think)
Also, if scope is without TFT data cable ferrite it is best to ask also it included in same shipping.
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OK so I need to open up the scope and read two version numbers, adapter board and PSU?
My scope serial number is SDS71021211675 - I bought it in summer 2012 - I presume it has the "bad" PSU and adapter board. I am going to open it now.
Owon need only your serial number.
You need new version PSU + you need version V3.3 Adapter board.
If you order from Owon and with this shipping price
Order newest SDS series PSU, New Adapter board V3.3 (but not newest V4.4) and new FAN and TFT data cable ferrite if there is not allready.
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OK I will now email them exactly as you wrote it :)
"Order newest SDS series PSU, New Adapter board V3.3 (but not newest V4.4) and new FAN and TFT data cable ferrite if there is not allready."
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OK I will now email them exactly as you wrote it :)
"Order newest SDS series PSU, New Adapter board V3.3 (but not newest V4.4) and new FAN and TFT data cable ferrite if there is not allready."
Do you know there is not this ferrite?
If there is not, you need it, if there is you do not need it.
You can see it after you open it. (this is missing from some older scopes but I do not know your scope)
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OK I am trying to open it now.
I have taken out the battery. It reads:
Li Polymer.
Cell: 4669120 / 4000 mAh/3.7V
Pack: 2S2P 7.4V / 8000 mAh
So this battery contains 4 cells of 3.7V each, put in series to give 7.4V and in parallel to give 2*4000mAh = 8000 mAh.
Or have they simply put two cells in series and then claim 8000 mAh ?
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OK I am trying to open it now.
I have taken out the battery. It reads:
Li Polymer.
Cell: 4669120 / 4000 mAh/3.7V
Pack: 2S2P 7.4V / 8000 mAh
So this battery contains 4 cells of 3.7V each, put in series to give 7.4V and in parallel to give 2*4000mAh = 8000 mAh.
Or have they simply put two cells in series and then claim 8000 mAh ?
It is 7.4V 8000mAh if there is two 3.7V 4000mAh cell series it is 7.4V 4000mAh.
There is "2 series, 2 parallel = 4 cells + of course control electronics also inside package.
Manufacturer is (typically) Hangzhou Wanma. (http://www.wanmabattery.com/Contact.en.asp)
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Yes i see 0Hz spike, it is wierd..... i think red marker (1) on the left of the screen should be referent not center of the screen, but it is not big problem, before doing FFT i just need to put CH to the center. Am I right?
Myself, I either do that or ignore the spike.
I have one more question about FFT.
When i change horizontal scale in Hz, horizontal scale in seconds (of the wave) is changing too. The same is happening with Vrms scale, but not with dB scale. Hope you understand.
This is stupid, i want to change X and Y scale of FFT not scale of the wave !!
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There is "2 series, 2 parallel = 4 cells + of course control electronics also inside package.
Manufacturer is (typically) Hangzhou Wanma. (http://www.wanmabattery.com/Contact.en.asp)
Ahh that is excellent. You see, if you go on ebay, there are dozens of Chinese LiOn battery packs, light blue in colour usually, claiming to be 12.6V/9600mAh when it fact they have 3 cells of 3.7V/3200mAh inside. That is thieving.
By the way, could you please point me to the message which shows how to open up the Owon ? I have taken 4 screws out the back but the back cover will not budge.
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Yes i see 0Hz spike, it is wierd..... i think red marker (1) on the left of the screen should be referent not center of the screen, but it is not big problem, before doing FFT i just need to put CH to the center. Am I right?
Myself, I either do that or ignore the spike.
I have one more question about FFT.
When i change horizontal scale in Hz, horizontal scale in seconds (of the wave) is changing too. The same is happening with Vrms scale, but not with dB scale. Hope you understand.
This is stupid, i want to change X and Y scale of FFT not scale of the wave !!
Yes, the two are connected, so it's somewhat inconvenient. I'm not sure if this is implemented the same on DSOs from other manufacturers. It would be nice to know if someone has the answer. But this is not a malfunction on your scope, mine works the same way.
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There is "2 series, 2 parallel = 4 cells + of course control electronics also inside package.
Manufacturer is (typically) Hangzhou Wanma. (http://www.wanmabattery.com/Contact.en.asp)
Ahh that is excellent. You see, if you go on ebay, there are dozens of Chinese LiOn battery packs, light blue in colour usually, claiming to be 12.6V/9600mAh when it fact they have 3 cells of 3.7V/3200mAh inside. That is thieving.
By the way, could you please point me to the message which shows how to open up the Owon ? I have taken 4 screws out the back but the back cover will not budge.
Check this video: Just be careful with the Pwr button, you have to push it down while opening the top half of the cabinet.
SDS Teardown (https://www.youtube.com/watch?v=Zct3Ircz6nY#)
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OK thanks for the video. I have taken these pictures
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I see you have proceed!
Your PSU version is the same like Adrejanko, very bad version!
Your adapter version is 3.0 like me.
It is better to change both of them, as rf-loop told. I am very sure that you haven't the flat ferrite on tft cable, too.
Send an email to Owon for these 3 items and ask a better price.
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After I change the PSU and the adapter board the scope will be good ? Will I be able to measure low signals, like 100mV ?
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Yes i see 0Hz spike, it is wierd..... i think red marker (1) on the left of the screen should be referent not center of the screen, but it is not big problem, before doing FFT i just need to put CH to the center. Am I right?
Myself, I either do that or ignore the spike.
I have one more question about FFT.
When i change horizontal scale in Hz, horizontal scale in seconds (of the wave) is changing too. The same is happening with Vrms scale, but not with dB scale. Hope you understand.
This is stupid, i want to change X and Y scale of FFT not scale of the wave !!
Yeah, that's how it works. I wrote a long post refuting your claim that timebase setting is not relevant to FFT setting with measurement examples, but my computer ate it and I of course did not back up the data. Timebase is affected in dB mode as well, but it may not be as obvious. For example, set your CH1 to 10 ns/div and go to FFT. On my scope, it goes to 400 MHz/div. Once I mode it to say 5 kHz/div and exit FFT mode, scope is in 1 ms/div. Also sometimes, the timebase will change but the timebase indicator will not change. This almost always happens when doing self-calibration, but I think it happened a few times to me with FFT mode as well.
You can't actually do what you want, since FFT data is (obviously) just calculated from the samples taken from the X and Y waves. In FFT mode with Vrms set, you're actually directly controlling the volts/divs scale directly and FFT is calculated by the method described in the manual. Scope takes 2048 samples from the channel, calculates FFT using that samples and puts it into 1024 bins. You can either set the channel and go to FFT mode, or you can set the channel indirectly in the FFT mode.
I'm not sure what they're doing in dB mode for voltage ranges...
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Order newest SDS series PSU, New Adapter board V3.3 (but not newest V4.4) and new FAN and TFT data cable ferrite if there is not allready.
So now the fan cable has a ferrite as well? If so, I might add one to my fan too. Are there any specifications or pictures of the ferrite available?
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Richtek USA has very good support, they provide samples easy. Can you see what marks has?
I don't know what kind is LF1, but you have measured 75mH at your schematics and the Owon's service schematic says 10mH!
Have you looking there?:http://gr.mouser.com/search/refine.aspx?Ntk=P_MarCom&Ntt=120657723 (http://gr.mouser.com/search/refine.aspx?Ntk=P_MarCom&Ntt=120657723)
The marking is DP=JOM, so it seems to be the right part, see attachment.
I had checked Mouser before, the US site, but they don't have something that will fit, at least in the 75mH-100mH. Like you said, the Service Manual Schematic says 10mH. I measured 75mH in circuit, but in circuit measurements can easily be incorrect.
I rewound one of the choke's coil with AWG 30 but could only fit 70 turns. When I checked the inductance it was slightly less than 1mH. This reading may not have been very accurate because one of the core's C halves broke in two. I was able to put everything together anyway, but the junction where the core broke may be causing a reduction in the inductance, however, I doubt it would be 30mH less for example. Anyway, I'm thinking now that perhaps the real value may be 10mH like the Service Manual says. So I'm going to look for some chokes with that value. In any case, this part is not essential for the PSU's operation, it's only there so that the product can pass the EMI requirements as far as interference with other equipment connected to the same AC source.
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Order newest SDS series PSU, New Adapter board V3.3 (but not newest V4.4) and new FAN and TFT data cable ferrite if there is not allready.
So now the fan cable has a ferrite as well? If so, I might add one to my fan too. Are there any specifications or pictures of the ferrite available?
FAN cable do not need any ferrite.
I recommend "akis" to order also new fan so that he have new FAN for future possible needs becouse it can ship together with other parts now and also becouse he plan change PSU+Adapter and when scope is open, if there is any sign of bad FAN it is clever to change always when scope is in service.
Then I ask he check if TFT data cable if there is ferrite missing (becouse some older scope do not have this) and order also this ferrite from Owon.
TFT data cable need ferrite.
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Thanks for clearing that up rf-loop!
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After I change the PSU and the adapter board the scope will be good ? Will I be able to measure low signals, like 100mV ?
Chances are that it will. But as I'm sure you know, there are no absolute warranties on anything!
The new PSU and adapter board have given good results so far for several of our members. I ordered a new PSU from Owon and had good results. My scope is able to measure low level signals, less than 1 gradicule at 50mV/Div full bandwidth and trigger properly on them. When the signal is less than around 35mV the trigger is no longer stable, but this happens anyway, even if I use the short GND clip. So it's no longer due to the GND noise.
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New adapter board version. (not for older scopes)
Older scopes can use V3.3 adapter latest upgraded versions.
But overall this V4.4 tell that Owon have done "hard work" and they have take this case really seriously. But they have talked less and worked more.
I see that keeps the same both connectors.
The version 4.4 still having the R-C network in the back?
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Richtek USA has very good support, they provide samples easy. Can you see what marks has?
I don't know what kind is LF1, but you have measured 75mH at your schematics and the Owon's service schematic says 10mH!
Have you looking there?:http://gr.mouser.com/search/refine.aspx?Ntk=P_MarCom&Ntt=120657723 (http://gr.mouser.com/search/refine.aspx?Ntk=P_MarCom&Ntt=120657723)
The marking is DP=JOM, so it seems to be the right part, see attachment....
Thanks for info. :-+
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I have ordered adapter board and power supply board from China. They charge $60.
I presume it is a straight forward replacement ?
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I have ordered adapter board and power supply board from China. They charge $60.
I presume it is a straight forward replacement ?
It should be, the new PSU board and the 3.3 adapter board are the same size as your current boards. Did you include the ferrite for the TFT panel cable on your order? Or does your scope already have it? See attachment. This is also required to get the best GND noise reduction.
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No it does not, and the lady at the other end of the email told me that I did not need it. I will write to her and ask her to put one in the box.
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Richtek USA has very good support, they provide samples easy. Can you see what marks has?
I don't know what kind is LF1, but you have measured 75mH at your schematics and the Owon's service schematic says 10mH!
Have you looking there?:http://gr.mouser.com/search/refine.aspx?Ntk=P_MarCom&Ntt=120657723 (http://gr.mouser.com/search/refine.aspx?Ntk=P_MarCom&Ntt=120657723)
The marking is DP=JOM, so it seems to be the right part, see attachment....
Thanks for info. :-+
You're welcome!
Is this the same markings your samples had?
I sent my order to Digi-Key last night. In addition to the MOSFET and SMD resistors, they also had a 10mH Common Mode Choke that fits and looks exactly like the original PSU choke. It evens has the correct DC resistance. So I'm pretty sure now that 10mH was always the correct value.
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No it does not, and the lady at the other end of the email told me that I did not need it. I will write to her and ask her to put one in the box.
Come on Lady, come on lady...what I say to her! This ferrite decrease 10mV the noise about!
If she doesn't send you, remember me to give you an equivalent from farnell.
Richtek USA has very good support, they provide samples easy. Can you see what marks has?
I don't know what kind is LF1, but you have measured 75mH at your schematics and the Owon's service schematic says 10mH!
Have you looking there?:http://gr.mouser.com/search/refine.aspx?Ntk=P_MarCom&Ntt=120657723 (http://gr.mouser.com/search/refine.aspx?Ntk=P_MarCom&Ntt=120657723)
The marking is DP=JOM, so it seems to be the right part, see attachment....
Thanks for info. :-+
You're welcome!
Is this the same markings your samples had?
I sent my order to Digi-Key last night. In addition to the MOSFET and SMD resistors, they also had a 10mH Common Mode Choke that fits and looks exactly like the original PSU choke. It evens has the correct DC resistance. So I'm pretty sure now that 10mH was always the correct value.
Yes, TomC it is exactly the same!
I see, you had a nice end of searching. Very good, your tests will be continue...
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Just installed the R7731A and couldn't wait for the rest of the parts to see if it worked. Since there is no Q1 installed, I knew there would have to be gate pulses trying to start up the PSU. So I got some captures of the waveforms at the R7731A gate. These show what happens when the R7731A is trying to start the PSU but the VDD never goes up because there is no Q1.
These captures were done while powering the PSU from my isolated Variac at 120VAC. With the isolated mains I was able to connect the scope's ground to GND-A.
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I have a question about FFT on this scope. I've been doing some captures of signals coming from FM and VHF antennas and I've noticed that when I do FFT of the signal, the greatest peak is not on the expected frequency. For example, I look at the station that's broadcasting at 104 MHz and I see the greatest peak at 104.2 MHz. There seems to be a 200 kHz offset on the entire FM band on results I see.
I exported some data to MATLAB and I can see a consistent offset there too, but it's much smaller. For example, for an FM station that's on 105.2 MHz, I see the greatest peak at around 105.215 MHz.
Any ideas what this could be? Somehow, I expect the stations to have pretty spot-on carrier frequency.
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I'm not sure if the FFT should be more accurate, but I think that the 0.2% accuracy that you report is pretty impressive. The manual recommends the rectangle window for best frequency accuracy, I wonder if that would be closer to the MATLAB results since presumably it would be using the same raw data.
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AFAIK Owon SDS series FFT use 2048 samples. It means theoretical maximum 1024 resolution. Resolution is not accuracy.
True samplerates are (example) 50, 100, 250, 500, 1000MSa/s and they respond 0 to 25, 50, 125, 250 and 500MHz FFT range.
If range is example 0 - 125MHz resolution is around 0.125MHz. with 0-250MHz range resolution is around 0.25MHz. If zoom, true resolution do not change.
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That's what I just realized! I guess I should do a bit more reading and experimenting with FFT. I did FFT on 1k capture in MATLAB and got worse results than on scope and when I did an FFT on 10k capture I got better results, as expected.
Thanks for explaining this!
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AFAIK Owon SDS series FFT use 2048 samples. It means theoretical maximum 1024 resolution. Resolution is not accuracy.
True samplerates are (example) 50, 100, 250, 500, 1000MSa/s and they respond 0 to 25, 50, 125, 250 and 500MHz FFT range.
If range is example 0 - 125MHz resolution is around 0.125MHz. with 0-250MHz range resolution is around 0.25MHz. If zoom, true resolution do not change.
That clears it up!
Thanks
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Well, the PSU is repaired, however, I have noticed some differences in behavior as opposed to before the accident. In general, the noise generated by the 8.4V is less, however, as far as total noise is concerned there don't seem to be much of a difference. Attached are some captures of the repaired PSU paired to the equivalent captures that I previously posted on post #2072 before the accident. The images on the right are from the repaired PSU.
There is one other thing that is different, the frequency of the oscillator remains constant regardless of the mains voltage. When I tested my new PSU some time ago I had reported that the frequency decreased as the mains voltage increased. I also observed this behavior on my old PSU the day of the accident. Unfortunately, the accident occurred before I had time to capture some images. This makes me wonder if the PWM controller that Owon uses on these PSUs is actually built by Richtek. For all I know it could be a cheaper knockoff built in the mainland.
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Odd problems w SDS7102V:
The Vertical Volts/Div knob will sometimes increase when turned clockwise, will sometimes DECREASE when turning same direction. It is random. Same for counter-clockwise. Is random which way the volts/div changes.
The scope will not trigger (very simple test 300khz 1volt sine wave) at times and the only way to correct it is to reboot.
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TomC, the comparative results is almost identical, with a little differences (as you told, of course).
OK, we'll wait for the continue... :-+
@ pullin-gs = this is bad! This happens on both channels or the one specific? How long you have the scope and how to use it until now?
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I have owned it for 18 months.
Ch1 and Ch2 both experience the same problem when turning the Volts/Div knob. This is a new problem which I noticed after it had not been used for the last 6 months. I pull it out for field work about once every 6 months typically to troubleshoot ANSI standards compliance with telecommunications circuits.
As far as the trigger is concerned, it seems to only happen when setting up "ALT" trigger mode w/both channels and after I have played around with it for a spell. Seems like a firmware bug????
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Well, the PSU is repaired, however, I have noticed some differences in behavior as opposed to before the accident. In general, the noise generated by the 8.4V is less, however, as far as total noise is concerned there don't seem to be much of a difference. Attached are some captures of the repaired PSU paired to the equivalent captures that I previously posted on post #2072 before the accident. The images on the right are from the repaired PSU.
There is one other thing that is different, the frequency of the oscillator remains constant regardless of the mains voltage. When I tested my new PSU some time ago I had reported that the frequency decreased as the mains voltage increased. I also observed this behavior on my old PSU the day of the accident. Unfortunately, the accident occurred before I had time to capture some images. This makes me wonder if the PWM controller that Owon uses on these PSUs is actually built by Richtek. For all I know it could be a cheaper knockoff built in the mainland.
Congratulations Tom, I'm glad that you could repair it. :) :-+
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I have owned it for 18 months.
Ch1 and Ch2 both experience the same problem when turning the Volts/Div knob. This is a new problem which I noticed after it had not been used for the last 6 months. I pull it out for field work about once every 6 months typically to troubleshoot ANSI standards compliance with telecommunications circuits.
As far as the trigger is concerned, it seems to only happen when setting up "ALT" trigger mode w/both channels and after I have played around with it for a spell. Seems like a firmware bug????
Your scope is still under Warranty! I would contact the dealer first, and if that don't yield the results you expect contact Owon directly. There are also firmware upgrades recently released, you may want to check those out:
http://www.owon.com.hk/service_s.asp?SortID_1=3 (http://www.owon.com.hk/service_s.asp?SortID_1=3)
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Lemon & Carrington,
Thanks for the encouragement :)
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Today's test involved replacing D5 (1N4007) with a fast recovery rectifier (UF4007). First the R2CD circuit was left intact, next it was changed to a traditional RCD clamp by shorting R4 & R4A. The performance of both configurations was very similar. Surprisingly, the original R2CD circuit with the 1N4007 does a better job of clamping the voltage and dampening oscillations. As far as the overall noise, it doesn't seem to change very much. Given these results, I now think that it's best to leave this circuit unmodified. So I have changed D5 back to a 1N4007 rectifier. The captures show side by side the results for the original R2CD with the 1N4007 (left side) and the RCD clamp with the UF4007 (right side).
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There is a new SDS-E series of Owon scopes. But it is not bettter than the original SDS series.
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There is a new SDS-E series of Owon scopes. But it is not bettter than the original SDS series.
Also SDS-E is NOT more new version for SmartDS series scopes.
This SDS-E is more like upgraded very old PDS serie. And added some more new versions
First there was SDS5032E what was time ago made for replace ancient model PDS5022S. (STN display) Also there was middletime version PDS5022T (TFT diplay) and later it was replaced with SDS5032E and now they have made more models for this E-conomy "basic school classroom" product serie.
SmartDS serie continue living its life independent of this "E"-conomy" series..
They are different product series. SDS-E and then SmartDS series.
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:-+
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Today's test involved installing a Belly Strap on TR1. This caused a decrease in the field surrounding TR1, specially around the area where D5 is installed. As far as the noise is concerned there is a visible improvement on the noise observed on the Pwr Sw cover, however, the noise observed on the pseudo Z-plate is around the same.
The Belly Strap was built with HVAC aluminum tape. For the strap to work it must be electrically connected at the joint, so as to form a continuous conductive ring. So I folded the tape at the joint of the top & bottom ends of the tape so that the aluminum side of the top end would contact the aluminum side of the bottom end. Then I placed a piece of tape over the joint to hold the assembly together.
The one negative about this mod is that the current flowing through this strap, which partially cancels TR1's near field, also produces heat. The strap's temperature eventually rises to 50C, the top of TR1 which normally runs around 40C rises to 45C. Naturally this wasted energy will have some impact on the efficiency of the PSU, something that I didn't quantify during this experiment.
At this point I'm not convinced that the moderate reduction in the field out weights the negative side effects of this mod. I need to see if there is significant improvement in the GND noise when the PSU is installed in the scope. On the side by side captures the images on the right are with the Belly Strap installed.
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Step by step to the sucess, TomC.
It is very interesting all your findings.
Although there isn't noise improvement on the pseydo-z plate, however we don't know how will be on the real z-plate. Keep walking to your magic psu investigation.
At the end if I remember well, someone (AndrejaKo or you) had used fast diodes on psu and the results were no better than the initial slow diodes.
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Yeah, I tried fast diodes and they didn't help at all. In fact, one specific diode had negative effect, since it prevented battery charging under certain conditions.
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Well done Tom, maybe that the effect is not noticeable in the GND noise, but for sure it reduced EMI.
Both, the use of the small toroidal core for L2 and the Belly Strap are cheap and easy to do.
Unfortunately I believe that little more can be done, because make all the necessary changes is almost impossible. For example how apply a improvement to reduce the EMI in the connector between the "mainboard" and the DC/DC board?
Well I think that still remain something that can be improved easily, replace the DC/DC (see atached image) by a good linear regulator, like LP38853 or LP38513-ADJ (see pag 11 at ADC0xD1520RB_R1_Schematic_07-27-2K12.pdf). Well may not be so easy.
http://www.ti.com/tool/adc08d1520rb (http://www.ti.com/tool/adc08d1520rb)
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Can anyone try to confirm this bug:
I had channel one active and channel two disabled and I captured data from channel one in single shot mode. After capturing data, scope went into stop mode, as expected. Then I turned off channel one and turned on channel two. Channel two displayed signal from channel one! Firmware version on my scope is 2.8.1.6 from the newest version of 3.3 patch.
It does same thing if capture is made on CH2 and them we move to CH1.
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I confirme the same.
At Run Stop if you activate/deactivate the channels the captured image transfer to other channel.
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Hello.
Does anyone have the SDS6062 model? I bought one and it will arrive next week. I am interested in this "noise" issue as it may affect the 60mhz model as well. The one that I bought is 1301 series (first week of 2013?). The seller was kind enough to give me the serial number.
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Hello.
Does anyone have the SDS6062 model? I bought one and it will arrive next week. I am interested in this "noise" issue as it may affect the 60mhz model as well. The one that I bought is 1301 series (first week of 2013?). The seller was kind enough to give me the serial number.
The information that we have is that serial 1319xxx is the breakpoint for the low noise mods. However, I seem to remember someone else that bought an SDS6062 prior to that serial and had good results. Perhaps someone else can confirm this?
Edit: This is the post I was thinking about: https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/msg212002/#msg212002 (https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/msg212002/#msg212002)
However, I'm not sure that he was performing the noise test correctly.
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Today I tried my Old PSU in the scope. The only alterations at this point are the L2 inductor that I replaced with a toroid and the Belly Strap on TR1. There are no additional bypass capacitors or alterations to the printed circuit.
I started by calibrating the scope and capturing the noise for my New PSU. Note that I had a ferrite on the PSU to adapter cable during this first set of captures. Next, I installed my Old PSU but left the ferrite on the PSU/adapter cable off. For the last set of captures I installed the ferrite on the PSU/adapter cable.
For all three sets of captures the probe cable was looped and sitting on the same surface as the scope. Also note, that as I have indicated before, my probe cables are equipped with ferrites at both ends to limit external interference. While viewing the signals only the CH1 probe was connected to the scope, the USB cable and the Laptop were kept away from the scope and all nearby fluorescent lights were off. To capture each signal I stopped the scope and then connected the USB cable and the Laptop.
On the side by side images the image on the left is for my new PSU (with a ferrite on the PSU to adapter cable), the center is for my old PSU, and the right for my old PSU with the ferrite on the PSU to adapter cable.
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Congratulations TomC.
From what I see, the old psu with only two mods (belly strap on TR1 & new L2) is at least identical to new psu.
I don't know what else you are thinking to try about old psu but I am thinking if there is a reason to put the decoupling capacitors.
From the average measurement seems that the ferrite absorbs the noise almost 4mV. From this aspect the decoupling capacitors perhaps to help more.
It is interesting at the sample measurement the capture of old psu with frt hasn't any periodical noise that the new has. I don't know if this is stable all the time like here but if it is true is more important from the improvement of value (26->22mV).
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Hello.
Does anyone have the SDS6062 model? I bought one and it will arrive next week. I am interested in this "noise" issue as it may affect the 60mhz model as well. The one that I bought is 1301 series (first week of 2013?). The seller was kind enough to give me the serial number.
The information that we have is that serial 1319xxx is the breakpoint for the low noise mods. However, I seem to remember someone else that bought an SDS6062 prior to that serial and had good results. Perhaps someone else can confirm this?
Edit: This is the post I was thinking about: https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/msg212002/#msg212002 (https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/msg212002/#msg212002)
However, I'm not sure that he was performing the noise test correctly.
Thank you for the info.
I already sent an email to the seller asking him the best route to tackle this issue since I already payed for the scope. On monday he should send it out to me but I might wait for a newer batch since he said that if I need a carrying bag he is finishing another order at Owon next week.
I already saw that user's comments and I also am not sure if he did the test with the proper settings. I sent a pm to him and hope he comes back with good info.
Is there anyone with this 6062 model that cares to share some info? Maybe some pictures with an opened one?
Is the revised psu+adapter card as expected? Something in the range of the other similar prices scopes?
Also I'm planning on using this for audio work so I'll need to look for low levels of noise in smps power supplies. I'm a beginner in this field but I would like to not be limited by this issue further on as I progress.
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Congratulations TomC.
From what I see, the old psu with only two mods (belly strap on TR1 & new L2) is at least identical to new psu.
I don't know what else you are thinking to try about old psu but I am thinking if there is a reason to put the decoupling capacitors.
From the average measurement seems that the ferrite absorbs the noise almost 4mV. From this aspect the decoupling capacitors perhaps to help more.
It is interesting at the sample measurement the capture of old psu with frt hasn't any periodical noise that the new has. I don't know if this is stable all the time like here but if it is true is more important from the improvement of value (26->22mV).
Yes, in fact, as you said, the old PSU with the mods works a little better than the new one, and the periodical noise is less. The captures don't show all the dynamics, except for the Avg16 capture that is almost perfectly consistent. But even looking at the signals dynamically it's obvious that the old PSU+ferrite has a little less GND noise than the new PSU+ferrite.
At this point I don't plan to pursue further reductions in GND noise via mods to the PSU. I feel that the remaining GND noise is inconsequential to measuring low level signals while using the long ground lead. I just wanted to see if it was possible to reduce the GND noise on older PSUs with easily implemented mods. At least to a level where this type of measurements can be accomplished unhindered. I think these mods may be sufficient to accomplish that goal, what remains to be seen is if other members can duplicate this results.
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TomC, when I received my new psu, I'll do the same mods like yours.
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I would like to find more information about Backlight IC control at the adapter board on version 3.2/3.3
From what we know, it is a chinesse clone of TPS61161A with OBT marking. This same marking OBT uses and TI, too but the image of IC is different with other socket.
(http://www.ti.com/graphics/folders/partimages/TPS61161A.jpg)
The better photo that we have is from member Flash2light here (https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/msg275269/#msg275269)
(https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/?action=dlattach;attach=57304;image)
Have anyone member has any information about this ...rf-loop maybe?
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RE: Noise:Why not just get the $50 battery and be done with it??
I only plug it in to charge the battery.
I find it much more convenient to use with a battery also.
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RE: Noise:Why not just get the $50 battery and be done with it??
I only plug it in to charge the battery.
I find it much more convenient to use with a battery also.
The battery only takes the place of the 8.4V supply, so it only precludes the noise generated by this part of the PSU which doesn't generate the bulk of the GND noise. Most of the noise comes from the -7.6V supply in the PSU and several other DC/DC converters in the adapter board. So for users with the older PSU and adapter board a battery doesn't resolve the problem. In fact, many of the users involved in the GND noise discussion have the battery option.
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So much about Owon noise, nearly like it is only Owon special problem and all others do not have.
Here looked Owon, Siglent and Hantek. With as same settings as can. All tests probe comp is adjusted for scope and in all tests exactly same probe.
Vertical 50mV/div with probe setting 10x in scope and in probe. (real scope input is of course then 5mVdiv) Coupling DC.
Horizontal 500us exept Hnatek 400us / div.
Normal sampling, and memory 1M Owon, 2M siglent, 1M Hantek.
Display persistence 5s.
All scopes first image input open, next probe in input but shorted as in pictutre. Then Probe connected to Comp Out GND as see in image. Last probe connected normally to Probe Comp output.
Environment: all switch mode supplies shutted off, computrers off. Only this scope connected to mains what is under test. Even Lights are linear DC supply powerered LED. Not strong TV, FM or AM stations nearby. Also building WLAN shutted off.
Owon, Siglent and Hantek all are 100MHz models without modifications.
Just for fun and for realize what is what in this heavy talk about just Owon noise.
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Great job rf-loop. :-+
Another way to look:
(https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/?action=dlattach;attach=64190;image)
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Great job guys! :clap:
I really enjoyed the individual pictures and the side by sides of the three scopes being tested under nearly identical conditions. This should also be posted on some of the other threads discussing DSOs.
Maybe this will help dispel the myth that Owon scopes must be noisier than all others since the Owon thread has so much content dealing with this subject.
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Realy great job, rf-loop :-+
You have right that there is wrong impression among the members of this forum about Owon's noise.
It was wrong of Owon, cause wrong initial warranty coverage.
In my country there is a saying that says "better to your eye goes despite the name" ... has to do with the fame.
Anyway, 5-6 members of us keep this thread with our investigation how to eliminated the noise to old noiser SDS7102 not new that all we know that there is no noise, more.
At the start of this month, for the same reason like your thought, I have start a new thread with the title "A method for evaluate your oscilloscopes ground noise?" (https://www.eevblog.com/forum/testgear/comparison-of-oscilloscopes-ground-noise/) but there is no results and some members have different aspect about this.
But your comparing results are to the same place and same probe and here is the true!
Congratulation for me!
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I bought SDS7102 few weeks ago and my MATH button is light blue. I saw pictures on the internet and the MATH button is white. Is that sign of new version, i can see rf-loops sds7102 has light blue button too. BTW rf-loop very nice job :-+.
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Another way to look:
/image/
ehm no, never ever like that. I think rf-loop made images to have an "feeling" how something looks ike on specific model and not to compare directly pictures. When compare then scale first screens to have same resolution/pix per DIV/data points per pix/intensity full on/etc. Much better is to measure Vpp and/or Vrms and compare results, and even here one should be carefull with buffer depth and methodology of measurment (which didn't matter for these 3 models however).
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Your observations have true base and the Vpp or Vrms will be the best for comparative results, but here we have the same methodology, the same position, the same time, the same probe, the same vertical resolution (50mV) the same or very closed horizontal time (400/500usec) and the closer memory buffer 1-2M).
Additional from what I see there is stable optical depth of camera.
I think that they are comparable.
This that is important to see, is if the Carrington's captures have the same resolution and not have zoomed. But in general, if we see the vertical and horizontal spaces are almost idenctical to the three images in series.
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I bought SDS7102 few weeks ago and my MATH button is light blue. I saw pictures on the internet and the MATH button is white. Is that sign of new version, i can see rf-loops sds7102 has light blue button too. BTW rf-loop very nice job :-+.
Yes, probably you have right. My that is a middle of 2012 model has a white FFT button.
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I received today the replacement adapter and PSU from Owon in China. I have received:
1) adapter board v3.0 dated 2011.11.14
2) adapter board v3.2 dated 2012.07.24
3) PSU board , no version on it, however it is slightly different to the one I have, for one it does not have a hole and a TO-220 transistor through it.
4) No ferrite! The lady from Owon said that this ferrite is attached to the LCD and so she did not send it to me. Whatever that means!
During the tests I have seen the greatest noise when the looped probe cable is near the bottom of the LCD. Does that mean that the LCD emits more noise than the adapter and the PSU together?
OK, I am changing the boards over now and will take some pictures if there are any good results.
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4) No ferrite! The lady from Owon said that this ferrite is attached to the LCD and so she did not send it to me. Whatever that means!
If you look carefully at the pictures of new LCD screens, you'll see that it is in fact true. The ferrite is glued to the metal case of the LCD/Z-plate assembly and the flat flex cable is run through it. Still that's not a reason not to send you the ferrite. You can easily fix it in place yourself or use the battery holder to keep it in place. That's what I did with my ferrite.
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I talked to the seller of my Owon sds6062v and he managed to talk to Owon factory and order a new batch of 6062 units. He specifically asked for newer version something like > 1330 production date. In a couple of weeks I should get mine and I will also post the results of the noise test. If I won't loose my warranty on it I will open it up and post some pictures of the psu/adapter board as I didn't see any from this model. Should help anyone who is considering getting the little brother of 7102 :)
Is there a warranty void sticker on these units?
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OK, I present here a picture "before" and two "after". One picture was taken with the probe cable tucked under the screen - this is the worst interference position - also you can loop the probe cable around the Owon for similar "bad" results.
Maybe the missing ferrite might help, but as it is a flat shape, has anyone got a part number I can get it from somewhere?
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Is there a warranty void sticker on these units?
Not on my unit. Haven't heard of anybody else finding one on their units.
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OK, I present here a picture "before" and two "after". One picture was taken with the probe cable tucked under the screen - this is the worst interference position - also you can loop the probe cable around the Owon for similar "bad" results.
Maybe the missing ferrite might help, but as it is a flat shape, has anyone got a part number I can get it from somewhere?
The ferrite on the TFT cable should help some. I believe Lemon has a part number from Farnell, he'll give it to you when he comes online. What I also do to limit the antenna effect of the probe cables, which is the main reason you see this increased noise when the cable is close to the TFT panel, is ferrites on the probe cable itself. One near the BNC, and one near the probe itself. I use the type intended for power cables, that way I can loop the cable around the ferrites for double the inductance.
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This ferrite absorbs about 10-15mV from that I have seen.
Here is the link for the appropriate flat ferrite
http://export.farnell.com/jsp/search/productdetail.jsp?SKU=3538369 (http://export.farnell.com/jsp/search/productdetail.jsp?SKU=3538369)
If it doesn't open, here is the description:
Code=3538369
KE KITAGAWA - FPC-31-12K
FERRITE CORE, FLAT CABLE, 26MM
Impedance @ 100MHz: 66ohm
SVHC: No SVHC (19-Dec-2012)
External Depth: 12mm
External Length / Height: 5mm
External Width: 31mm
Ferrite Case Style: Flat Core
Impedance @ 25MHz Typ: 26ohm
Series: FPC
Are you sure that testing the scope as we referred?
https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/msg255469/#msg255469 (https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/msg255469/#msg255469)
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OK, I present here a picture "before" and two "after". One picture was taken with the probe cable tucked under the screen - this is the worst interference position - also you can loop the probe cable around the Owon for similar "bad" results.
Maybe the missing ferrite might help, but as it is a flat shape, has anyone got a part number I can get it from somewhere?
Wow! That's quite significant! How much did you pay for the new adapter board and PSU? I'm thinking of starting to save up for them, if I don't manage to fix my unit by myself.
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I was charged $60 (US dollars), $10 for the parts and $50 for the shipping. The $50 for the shipping is so high to disguise the real price and try to avoid import duty.
I think it has made quite a lot of change and is well worth it. Yes the LCD screen also makes a lot of noise, but if you keep the probe cable directly away from the scope, at 90 degrees angle, and for at least one foot (30 cm) distance, then there is absolutely no noise.
I am not sure if the ferrite would improve matters in that configuration?
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I received today the replacement adapter and PSU from Owon in China. I have received:
1) adapter board v3.0 dated 2011.11.14
2) adapter board v3.2 dated 2012.07.24
3) PSU board , no version on it, however it is slightly different to the one I have, for one it does not have a hole and a TO-220 transistor through it.
4) No ferrite! The lady from Owon said that this ferrite is attached to the LCD and so she did not send it to me. Whatever that means!
During the tests I have seen the greatest noise when the looped probe cable is near the bottom of the LCD. Does that mean that the LCD emits more noise than the adapter and the PSU together?
OK, I am changing the boards over now and will take some pictures if there are any good results.
- Oh men, adapter board v3.2. :palm: akis please converts it to v3.3, just add a capacitor.
- No ferrite! :palm:
Hey Owon... Fail!
I am not sure if the ferrite would improve matters in that configuration?
Is not a question of believing or not, that ferrite reduce noise.
Another link:
http://www.ebay.es/itm/190837205693 (http://www.ebay.es/itm/190837205693)
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This should be covered by the warranty:
(https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/?action=dlattach;attach=64259;image)
If something is right I support it, but if something is wrong I will not be in silent.
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You guys should be rewarded by Owon for the work you are doing to improve their product!
I don't know if I would put in the time and stress for such a thing. And this is not even for modding, upgrading the product, but to get it to function like it was designed to...
Granted you did a very good job for the owners of the defective (is it ok to call it that way?) units. But I guess that I wouldn't struggle so much with the problem, I would just wait it out and get the replacement parts.
Does anyone know the details of the company? Like how many employees and how many units produced, and the history of the company?
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Does anyone know the details of the company? Like how many employees and how many units produced, and the history of the company?
No idea, I only know what it says here:
http://www.owon.com.hk/about.asp?InID=66 (http://www.owon.com.hk/about.asp?InID=66)
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I received today the replacement adapter and PSU from Owon in China. I have received:
1) adapter board v3.0 dated 2011.11.14
2) adapter board v3.2 dated 2012.07.24
3) PSU board , no version on it, however it is slightly different to the one I have, for one it does not have a hole and a TO-220 transistor through it.
4) No ferrite! The lady from Owon said that this ferrite is attached to the LCD and so she did not send it to me. Whatever that means!
During the tests I have seen the greatest noise when the looped probe cable is near the bottom of the LCD. Does that mean that the LCD emits more noise than the adapter and the PSU together?
OK, I am changing the boards over now and will take some pictures if there are any good results.
- Oh men, adapter board v3.2. :palm: akis please converts it to v3.3, just add a capacitor.
- No ferrite! :palm:
Hey Owon... Fail!
I am not sure if the ferrite would improve matters in that configuration?
Is not a question of believing or not, that ferrite reduce noise.
Another link:
http://www.ebay.es/itm/190837205693 (http://www.ebay.es/itm/190837205693)
If this ferrite is the genuine Wurth item, as shown here http://uk.farnell.com/wurth-elektronik/7427228/ferrite-core-flat-cable-34mm/dp/1890713?Ntt=7427228 (http://uk.farnell.com/wurth-elektronik/7427228/ferrite-core-flat-cable-34mm/dp/1890713?Ntt=7427228)
then I am surprised he sells them for a fraction of the price we pay for them in the UK....
What capacitor do I need on the v3.2 to make it v3.3 ?
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What capacitor do I need on the v3.2 to make it v3.3 ?
Take a look at Carrington's post with a photo in it. There is a single SMD capacitor circled in red. You need to install that capacitor. It goes between legs of an electrolytic capacitor that's above it, if I remember correctly. The capacitor should be 1 nF.
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Ah I missed that photo. I will open the scope again tomorrow now. By the way, the new PSU had the power on off switch 2-3 mm to the right, and the button does not fit anymore! So I had to break the plastic tabs on the button to make it fit :)
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I was charged $60 (US dollars), $10 for the parts and $50 for the shipping. The $50 for the shipping is so high to disguise the real price and try to avoid import duty.
I think it has made quite a lot of change and is well worth it. Yes the LCD screen also makes a lot of noise, but if you keep the probe cable directly away from the scope, at 90 degrees angle, and for at least one foot (30 cm) distance, then there is absolutely no noise.
I am not sure if the ferrite would improve matters in that configuration?
That configuration is avoiding the near field of the TFT panel, which results in less EMI picked up by the probe cable, so you see less noise. However, keep in mind that this strong field is still present, and although it isn't impacting the probe cables, there are other nearby components, such as the Z-plate, that are affected by this field. Some of this effect results in conductive common mode noise, which you see as GND noise when it's converted to differential mode noise by the long ground lead. Installing the flat ferrite on the TFT flat cable reduces the field, so you have dual benefits, less radiated EMI, and less conductive common mode noise.
Also keep in mind that the probe cables are susceptible to EMI from any external source, not just the TFT panel, even the DUT may be a strong source, for example an SMPS. This is why I use ferrites on the probe cables themselves.
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Ah I missed that photo. I will open the scope again tomorrow now. By the way, the new PSU had the power on off switch 2-3 mm to the right, and the button does not fit anymore! So I had to break the plastic tabs on the button to make it fit :)
If Owon didn't provide you with separate 1000pF SMD capacitors, it's possible that the capacitor was installed at the factory on the 3.2 board that they sent you. This capacitor is the only difference between version 3.2 and version 3.3. When I received my new PSU, Owon included several 1000pF capacitors so that I could modify my 3.2 board myself. However, according to some sources, Owon has been refurbishing existing 3.2 boards to 3.3 by adding this capacitor.
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If this ferrite is the genuine Wurth item, as shown here http://uk.farnell.com/wurth-elektronik/7427228/ferrite-core-flat-cable-34mm/dp/1890713?Ntt=7427228 (http://uk.farnell.com/wurth-elektronik/7427228/ferrite-core-flat-cable-34mm/dp/1890713?Ntt=7427228)
then I am surprised he sells them for a fraction of the price we pay for them in the UK....
That ferrite is even better, watch their price here:
http://www.digikey.com/product-search/en?x=11&y=17&lang=en&site=us&KeyWords=7427228 (http://www.digikey.com/product-search/en?x=11&y=17&lang=en&site=us&KeyWords=7427228)
That configuration is avoiding the near field of the TFT panel, which results in less EMI picked up by the probe cable, so you see less noise. However, keep in mind that this strong field is still present, and although it isn't impacting the probe cables, there are other nearby components, such as the Z-plate, that are affected by this field. Some of this effect results in conductive common mode noise, which you see as GND noise when it's converted to differential mode noise by the long ground lead. Installing the flat ferrite on the TFT flat cable reduces the filed, so you have dual benefits, less radiated EMI, and less conductive common mode noise.
Also keep in mind that the probe cables are susceptible to EMI from any external source, not just the TFT panel, even the DUT may be a strong source, for example an SMPS. This is why I use ferrites on the probe cables themselves.
Explain this more clear is impossible. :-+
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Your observations have true base and the Vpp or Vrms will be the best for comparative results, but here we have the same methodology, the same position, the same time, the same probe, the same vertical resolution (50mV) the same or very closed horizontal time (400/500usec) and the closer memory buffer 1-2M).
Additional from what I see there is stable optical depth of camera.
I think that they are comparable.
and all that didn't matter when you do visual compare because of different display size, resolution, pixel per DIV, DIV per full ADC scale and finally dot size. In case of Owon and Hantek the resolution, size and DIV per ful ADC are different, but luckily Owon is having exact the same display type(tech. type)/manufacturer, so the dot size is the same so one can take screenshot from Hantek and 1:1 paste on Owon screenshot to compare (where of course one need to know that Hantek is doing as well 10DIV vertical, but visible are only 4.2 DIV where Owon is doing 10DIV and visible 10DIV). Siglent can't be compared to them as there are major differences.
You need to know as well that the way how the waveform is being displayed matter as well, this is where it make sense for visual compare to set intensity on full. The horizontal resolution (or actually visible dots per div and the way how they will get displayed) matter as well, there is difference between DSOs displaying only some peak dots or some amount of dots or all dots.
Anyway, let's compare measured values ...
Mine after all modifications to this test with the BNC Shorting Cap has 12-16mV (10X) on CH1 and 14-18mV on CH2.
(https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/?action=dlattach;attach=62441;image)
... from stock Hantek DSO5102BMV (50mV/DIV, 80us/DIV, 2Mpoint depth, trigger on peak to catch all spikes).
CH1 does have some more noise injected from the display, without display the level is the same as on CH2.
(https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/?action=dlattach;attach=64346;image)
(https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/?action=dlattach;attach=64348;image)
Question1: did you measured in peak detect trigger mode?
Question2: i assume the Vp displayed on your picture is in real Vpp and not real Vp, isn't?
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Tinhead, now I understand you better.
The Owon Vp measurement is a real Vp-p measurement with a chinglish marking!
My measurements with bnc shorted isn't a typical SDS7102 measurement becouse mine scope was a bad ground noise unit and I have a lot of mods about this.
Anyway this measurement was with 50mV/div, 100us/div, Probe 10X fullBW, Peak measurement, 1M memory.
Here one measurement with 10M memory set (the SDS7102 jump to 10M after 1M), here the range of noise is 10-12mVp-p.
At the last yours mesurements as the wave demonstrated, they seem like the Average measurement of SDS7102. Here another sample with this average measuement (the average was set to 4) but I don't think so that is the right measurement for the comparison, simple are identical as waveform together.
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At the last yours mesurements as the wave demonstrated, they seem like the Average measurement of SDS7102. Here another sample with this average measuement (the average was set to 4) but I don't think so that is the right measurement for the comparison
well, my pictures only looks like "avg", but they made in peak detect mode. This is due how Hantek is displaying the datapoints on display and how many of the real datapoints are displayed at once (in vectors mode it can display up to 20000 point per one DIV, which is 500 datapoints per display pixel. In Dots mode even up to 40000 points per one DIV, which is 1000 datapoints per display pixel). I can't tell you how Owon is doing this, for me it looks like "skip on similar", which speed up drawing (but it costs processing time), but as Owon is not DPO-like made this is probably the only way to go. But maybe i'm wrong, maybe Owon is displaying only smaller amout of datapoints per DIV (that could explain as well the look of the waveform on Owon). Hantek don't need to calculate anything, the data is already in buffer (and already written into that buffer multiple times during sampling), so it have to draw it only.
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I don't know how this really works but I quote another peak capture of other member with more mVp-p. Here is more clearly how the SDS7102 presents the peak measurement.
(https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/?action=dlattach;attach=64261;image)
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Hi tinhead!
I just can tell you that I had to enlarge/reduce each image to match the volt/div scale.
No idea about how owon SDS processes the data to be displayed. I don't know if rf-loop knows how.
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Hello people!
Oscilloscope SDS7102 1143. The second batch, MB V1.1 2011/9/30.
Have a problem. After pressing the power button and display the logo screen, oscilloscope clicks relay and the screen goes blank and device reboot. Trouble arises with mains power and battery life. External inspection of PCB has not revealed any obvious damage. The power supply is apparently working well.
There are any ideas?
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Have you contacted your dealer or Owon? What you describe doesn't sound good. The good news is that based on the MB date your scope is still under warranty.
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The following is a summary of my interpretation of the attached PDF.
Peak Detect Mode is supposed to alter the original signal so that the higher and lower voltage values are emphasized when the signal is displayed. This is typically done by examining a given number of samples and selecting just the higher and lower voltage values. Only these selected values are stored in the display memory. One advantage of this technique is that it is possible to store a larger amount of relevant information (the highs and lows) in a shorter span of display memory. So if display memory is scarce, using Peak Detect Mode allows the capture of high and low voltage levels that otherwise would be missed. From this perspective Peak Detect Mode can be viewed as a form of compression.
To try to uncover some of the inner workings of the SDS7102, I captured some signals using both Sample Mode and Peak Detect Mode. On the first set of captures, #1 - #3a, I tried to set up the worst possible environment for Sample Mode to see how much of a difference using Peak Detect Mode would make. The signal generator was set to as close to 100MHz as I could get and the scope was set to 50µs/Div with a 100K acquire length. With these settings the sample rate is 100MS/s, exactly the same frequency as the input signal. This yields a capture window of: 100,000/100,000,000 = 0.001s or 1ms. At 50µs/Div this results in 0.001/0.000050 = 20Div of display. The sampling time at 100MS/s is 1/100,000,000 = 0.00000001s or 10ns. Ten nanoseconds is also the length of a cycle of the 100MHz input signal. As a result, since the two are nearly synchronized, the samples should happen at the same point of each sine wave resulting in pretty much a straight line.
That's precisely what happens in Sample Mode. However, under the same conditions, Peak Detect Mode manages to detect a peak every 10ns. How can this be possible? The only answer that I can think of is that the sample rate is much higher than 100MS/s. I suspect that for Peak Detect Mode the SDS7102 uses the maximum sample rate, in this case 1GS/s. I also suspect that the memory is segmented into Display Memory, in this case 100K, and capture memory, where the 1GS/s are stored. From there I would think the firmware picks the high and low samples and stores them in the Display Memory.
The second set of captures, #4 - #6a, were obtained at 50µs/Div with a 1M acquire length. With these settings the sample rate is 1GS/s, plenty fast to properly display a 100MHz signal. So there aren't many surprises on the way Sample Mode and Peak Detect Mode behave in this case.
On the side by sides the signal on the left is Sample Mode and the signal on the right is Peak Detect Mode. The captures were obtained at 50µs/Div and the scope was stopped (#1 & #4). The remaining images were obtained by changing the time base while the scope was stopped.
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Peak Detect Mode is supposed to alter the original signal so that the higher and lower voltage values are emphasized when the signal is displayed. This is typically done by examining a given number of samples and selecting just the higher and lower voltage values. Only these selected values are stored in the display memory. One advantage of this technique is that it is possible to store a larger amount of relevant information (the highs and lows) in a shorter span of display memory. So if display memory is scarce, using Peak Detect Mode allows the capture of high and low voltage levels that otherwise would be missed. From this perspective Peak Detect Mode can be viewed as a form of compression.
Very good analysis with perfect documentation for how the peak mode is working for SDS7102. Thanks for that, TomC!
For this reason at the Peak Detect Mode the intermediate information between max and min is missed and appears only with some inclines lines.
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The only answer that I can think of is that the sample rate is much higher than 100MS/s. I suspect that for Peak Detect Mode the SDS7102 uses the maximum sample rate, in this case 1GS/s.
SDS series true ADC samplerate is allways 1GSa/s for single channel and 500MSa/s + 500MSa/s for two channels in use. This is what ever is displayed samplerate or samplerate in sampling buffer memory. ADC itself samplerate is not changed, never.
If scope samplerate is 100MSa/s in normal sampling mode it just take every 10'th sample and forward it to memory. If samplerate is 1MSa/s it just take every 1000's sample from ADC and forward it to memory. Other samples just dropped out.
In peak detect sampling mode it works some amount different.
If there is now 100MSa/s samplerate. (ADC works 1x 1GSa/s or 2x 500MSa/s. )
Very roughly and inaccurate principle: In case where it use 1GSa/s (one channel) it "listen" every sample what is coming from ADC every one ns. But it only select out min max pair (and becouse now 100MSa/s there is min-max result after every looked block (dependent of samplerate how long this block is.)
If example samplerate is 1MSa/s (take one sample and drop out 999) and if it calculate every 1000 samples block average, we have simple machines principle High-Resolution capture mode.
Of course perhaps it need also add noise to signal before ADC. Pity High_res is not implemented in this scope.
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In peak detect sampling mode it works some amount different.
If there is now 100MSa/s samplerate. (ADC works 1x 1GSa/s or 2x 500MSa/s. )
Very roughly and inaccurate principle: In case where it use 1GSa/s (one channel) it "listen" every sample what is coming from ADC every one ns. But it only select out min max pair (and becouse now 100MSa/s there is min-max result after every looked block (dependent of samplerate how long this block is.)
Thanks rf-loop for clarifying some of this!
What I'm wondering is how does it proceed to select the min/max pairs. Since it can't look ahead of time, the blocks have to be stored someplace for processing after the fact. I was thinking segmented memory like I mentioned in my post, but this can be implemented in a number of ways. For all I know it could just be temporary memory that is discarded after each block is processed using alternating buffers. Anyway, if you have any information on how Owon does this it would be interesting to know!
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I could be wrong, but I think that there's a good description of how that works in TI's datasheet for the ADC pattern used in Owon. I don't have the cloned and original part numbers right now, so I can't check.
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Have you contacted your dealer or Owon? What you describe doesn't sound good. The good news is that based on the MB date your scope is still under warranty.
Thanks for your response!
No, I have not written the seller, and yes, the 3-year warranty is not over yet. I will try to take advantage of warranty, if I can not repair this device yourself
In fact there are only 2 options:
- Firmware is was destroyed, and I could not recover it.
- Reset/reboot gives the supervisor of power and I want to try to find the source of the fault dips on supply voltages.
Who can show where there is a reset circuit?
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Have you tried to download it the firmware again to the scope or there is no any communication with this?
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Have you tried to download it the firmware again to the scope or there is no any communication with this?
Thanks you for quickly replay!
Yes, I tried to download the update of FW, but the scope periodically reboot. The device driver appears and disappears, and there is no way to stop this process.
Now I'm learning the power supply circuit of scope, which is located on the "Adapter plate". 3.3V stabilizer works well and correctly. There are doubts about the work of the regulator to 5V. The voltage measured at the terminals 34 and 35 of the connector U1 is about 5.4-5.5V, which I think is not correct.
In an attachment of the circuit containing the 5V regulator circuit and a current source for LED backlight (connector U12).
Unfortunately, I now can not activate this card without LED backlight - because the risk of destruction of its stabilizer. As soon as I will prepare a dummy load, I will write here about the results.
Thank you all for participating and forgive my Googlish
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I'm turned on "Adapter plate" without the motherboard. And yes, the regulator U13 gives 5.45V. And this is correct. In an attachment, a description of the chip. The reference voltage is 0.8V. Feedback resistors R18 = 10k, R19 + R21 = 56k +1.8 k. Thus, the calculated output voltage of stabilizer = 5.424V.
I believe that the "Adapter plate" is working properly.
Tomorrow I will try to explore on the motherboard. The problem apparently lies in it
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Muxa52,
Thanks for reporting your findings!
Unfortunately I don't have any firm ideas of what your problem may be or how to fix it, just a vague suspicion that it may be firmware related.
Hope that you are successful in your efforts!
Please let us know what you find. :)
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Muxa52
"Yes, I tried to download the update of FW, but the scope periodically reboot. The device driver appears and disappears, and there is no way to stop this process."
In this kind of situation DO NOT upgrade FW. (also 99% for that this is not FW problem. This is not windows PC what OS need suddenly reisntall or update after update becouse system destroy itself) If there is FW inside and check sum pass, it is very very rare it have some wrong bits.
If it reboot at wrong time during FW upgrade procedure is running it may destroy your scope to state where any kind of FW loading is impossible.
During FW upgrade procedure, oscilloscope need run rock steady until procedure itself reboot scope for finalize FW upgrade.
It is serusly writed: Do not shut off oscilloscope during FW upgrade procedure!
And it is same if oscilloscope have HW failure what shut system down (and perhaps reboots).
Follow service manual simply diagnose (troubleshoot) instructions and take contact to Owon after you can exatly explain what is symptom.
One question, (I suppose you have battery).
If you take battery out and run without battery, do this reboot still happend just same as with battery. If you have battery, do it reboot just same if you run scope with battery and mains power disconnected.
Btw, you name it 5V regulator on the Adapter board. It is (nominal) 5.5V supply what can do it from 6 - 8.4V. (Main PSU nominal 8.4V is in practice 6V to 8.4V)
Scope need (adapter board connection to main board) -7.6V, 5.5V, 3.3V and 8.4V (it can vary around 6 to 8.4V(max).
You can run it without adapter board and PSU with these voltages and look if it still reboots. It do not need display.
Also on the main board there is some regulators and SMPS circuits.
Reason may be what ever. Not only power lines. There is databus things, there is BGA chips where may be hidden bad soldering, there may be bad trace on the board some layer. Example I have seen one bad trace on the adapter board. Before solder mask there have been small damage on the copper foil. It have worked one year but in random situation, temperature or some mechanical stress change and this one trace is ok or broken. Under microscope I find this very very small break. In rare case reason may be what ever.
If failure can isolate so that you know if it is PSU, Adapter board, Main board, front banel board or sidepanel board or TFT module it is enough. This is not diy scope, exept if you change it to diy scope. It is product what have normal 3 year factory warranty.
First contact your seller. If seller is real seller who also have after sales customer care, he will help you. If you have purchased it from "box shipper" seller who only reship boxes, perhaps he can not help you.
If seller can not help then contact Owon for instructions how to do and perhaps for free shipping to manufacturer repair center using normal Owon RMA procedure or other instructions how to do.
Exept if you have destroyed warranty or purchased it from markets what do not cover international warranty. Also in this case, you can always get (free or with payment) spare parts or quite cheap repair service from Owon.
But, in what situation exactly it reboots.
Is it possible to see any dropout in voltages. Drop outs may be so short that normal DVM can not see it at all.
Btw, I can see metal pillar on the main bord near CH1 BNC. Did you have extra noise specially in CH1. Later this pillar have changed to plastic pillar. (it was other case before this later "noisy GND" issue) (only pillar what is very near CH1. Owon have send instructions and these pillars to many end users and also for Owon services if example seller have Owon service)
First, with this kind of failure, try get this scope to Owon RMA procedure. It may be also that Owon is interest to see what have happend becouse of course they also want know failures better for develop better)
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Have you tried to download it the firmware again to the scope or there is no any communication with this?
Thanks you for quickly replay!
Yes, I tried to download the update of FW, but the scope periodically reboot. The device driver appears and disappears, and there is no way to stop this process.
...
Before you examined that all said rf-loop do a check to your usb cable...
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Muxa52
"Yes, I tried to download the update of FW, but the scope periodically reboot. The device driver appears and disappears, and there is no way to stop this process."
In this kind of situation DO NOT upgrade FW. (also 99% for that this is not FW problem. This is not windows PC what OS need suddenly reisntall or update after update becouse system destroy itself) If there is FW inside and check sum pass, it is very very rare it have some wrong bits.
If it reboot at wrong time during FW upgrade procedure is running it may destroy your scope to state where any kind of FW loading is impossible.
During FW upgrade procedure, oscilloscope need run rock steady until procedure itself reboot scope for finalize FW upgrade.
It is serusly writed: Do not shut off oscilloscope during FW upgrade procedure!
And it is same if oscilloscope have HW failure what shut system down (and perhaps reboots).
Follow service manual simply diagnose (troubleshoot) instructions and take contact to Owon after you can exatly explain what is symptom.
Yes, I understand that. I even not tried to run the update utility.
One question, (I suppose you have battery).
If you take battery out and run without battery, do this reboot still happend just same as with battery. If you have battery, do it reboot just same if you run scope with battery and mains power disconnected.
Yes, scope reboots as on battery power only, and powered by the PSU (with/without battery)
Btw, you name it 5V regulator on the Adapter board. It is (nominal) 5.5V supply what can do it from 6 - 8.4V. (Main PSU nominal 8.4V is in practice 6V to 8.4V)
Scope need (adapter board connection to main board) -7.6V, 5.5V, 3.3V and 8.4V (it can vary around 6 to 8.4V(max).
You can run it without adapter board and PSU with these voltages and look if it still reboots. It do not need display.
By calculation I have determined that this source should produce 5.422V at a current of up to 5A (measured value of 5.45V). AOZ1094 chip has a minimum current limit of 6A.
Thank you for your comment about voltages . It adopted me into thinking that PSU and Adapter plate and are working properly and well
Also on the main board there is some regulators and SMPS circuits.
Yes, I plan to gather documentation on chips, located on the MB. At a minimum, the chip of analog supply TPS76850 has a PG (Power good) output. This signal can be used to reset the CPU.
I'm working remotely and do not have in home any appliances, except for the multimeter. I have to go to the ofice and take an oscilloscope for monitoring this and other signals.
Reason may be what ever. Not only power lines. There is databus things, there is BGA chips where may be hidden bad soldering, there may be bad trace on the board some layer. Example I have seen one bad trace on the adapter board. Before solder mask there have been small damage on the copper foil. It have worked one year but in random situation, temperature or some mechanical stress change and this one trace is ok or broken. Under microscope I find this very very small break. In rare case reason may be what ever.
If failure can isolate so that you know if it is PSU, Adapter board, Main board, front banel board or sidepanel board or TFT module it is enough. This is not diy scope, exept if you change it to diy scope. It is product what have normal 3 year factory warranty.
First contact your seller. If seller is real seller who also have after sales customer care, he will help you. If you have purchased it from "box shipper" seller who only reship boxes, perhaps he can not help you.
If seller can not help then contact Owon for instructions how to do and perhaps for free shipping to manufacturer repair center using normal Owon RMA procedure or other instructions how to do.
First contact your seller. If seller is real seller who also have after sales customer care, he will help you. If you have purchased it from "box shipper" seller who only reship boxes, perhaps he can not help you.
If seller can not help then contact Owon for instructions how to do and perhaps for free shipping to manufacturer repair center using normal Owon RMA procedure or other instructions how to do.
But, in what situation exactly it reboots.
Is it possible to see any dropout in voltages. Drop outs may be so short that normal DVM can not see it at all.
Unfortunately I can not use the standard free procedure, since the device was purchased as a consumer device, and do not miss the free parcel customs. In any case, the cost of delivery will not stop me. I was stopped by a great time of delivery parcel. Now I plan to try to repair the unit yourself.
Btw, I can see metal pillar on the main bord near CH1 BNC. Did you have extra noise specially in CH1. Later this pillar have changed to plastic pillar. (it was other case before this later "noisy GND" issue) (only pillar what is very near CH1. Owon have send instructions and these pillars to many end users and also for Owon services if example seller have Owon service)
Yes, I read about the noise in channel 1, but they are not great, about 5 mV. I did not change the pillar, because I do not want to measure very weak signals. The measurement of digital signals, this noise does not affect
First, with this kind of failure, try get this scope to Owon RMA procedure. It may be also that Owon is interest to see what have happend becouse of course they also want know failures better for develop better)
Yes, I will try to contact the Owon, but it requires some effort from me. I am well read and understand technical English, but absolutely do not have the practice of spoken language, and do not feel the style of a written text. For this reason, I am embarrassed of me English texts and The Google translator does not help me.
On the other hand, I, as a developer of industrial electronics, I get a lot of experience studying other people's creations. Regarding this device can tell you that at least PSU developed highly economically, but it is possible that the battery charging circuit designed for extremely basic level. This does not help extend battery life. Uses a simple current limiter, but the battery like in the beginning of charge the high-current charge, and only after the main charge of high current (with temperature control of battery) is possible charge current limit.
In the scheme of supply LED backlight, stabilizer G5126 possible breakdown of high voltage (greater than 28V) in the case of a breaking LED backlight and open-circuit load. Developers forgot one resistor in parallel load circuit. Never turn on "Adapter plate", if not connected LED backlight. There is a probability of failure of the G5126.
Have you tried to download it the firmware again to the scope or there is no any communication with this?
Thanks you for quickly replay!
Yes, I tried to download the update of FW, but the scope periodically reboot. The device driver appears and disappears, and there is no way to stop this process.
...
Before you examined that all said rf-loop do a check to your usb cable...
USB cable in order and the driver is installed. I finally came to the conclusion that there is a hardware reset signal, which is produced by an over-current analog circuits of the motherboard, you turn them on. On MB I counted on one pulse and 3 linear voltage regulator. It is possible that the board has still some sort of a scheme of testing analog voltages, which provides a hardware reset signal. Most likely out of order one of the decoupling capacitors or (worse) chip ADC (MT2002). Now I plan to explore this part of the scheme.
Thank you all for participating in the discussion. I will write about their results.
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Muxa52,
Thanks for reporting your findings!
Unfortunately I don't have any firm ideas of what your problem may be or how to fix it, just a vague suspicion that it may be firmware related.
Hope that you are successful in your efforts!
Please let us know what you find. :)
Thank you for your participation. I read online about a case where such fails after saving the measurement results. But just as I was reading about a few cases where this effect was associated with a malfunction of the power supply. I regard the probability of FW / HW failure, as 50/50%.
Here's a video of such a failure (from 0.40 '), but I have no picture interference.
http://youtu.be/e4iRH-DENBw (http://youtu.be/e4iRH-DENBw)
Yes, I'll write about the results of my research.
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Muxa52
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And trying to debug via JTAG? Or upgrade FW?
http://radiokot.ru/forum/viewtopic.php?f=10&t=70052&sid=c1c18115b263a82e84503efc6c119f61&start=60 (http://radiokot.ru/forum/viewtopic.php?f=10&t=70052&sid=c1c18115b263a82e84503efc6c119f61&start=60)
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Muxa52
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And trying to debug via JTAG? Or upgrade FW?
Thank you for your suggestion!
I do not have the appropriate JTAG adapter. In addition, Samsung provides access to documentation and developer tools of processor on a separate individual agreement. Finally, for the firmware via JTAG need to have the image of ROM, which can not be obtained from the update FW. Owon will not give it to me, because this is the subject of her property.
I'll send the oscilloscope on the warranty, if I am sure that the problem is in the software.
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Muxa52, BBAAHHOO thanks guys, I had not seen the page 17 of this topic, this has helped me to resolve some of the questions that I had.
Muxa52 I hope you get lucky.
"tinhead" You say" I don't want to be human!" I say you are a machine.
Did you find the BSDL model for S3C2416?
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BSDL model for S3C2416? - As long as there is no experience.
The matter was only CPU RT 3052
And you have some experience with S3C2416?
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BSDL model for S3C2416? - As long as there is no experience.
The matter was only CPU RT 3052
And you have some experience with S3C2416?
No, I have no experience with the S3C2416.
I do not understand. Why the RT3052? Is a Ralink SoC with a MIPS32 24KEc core.
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RT3052 - it is used in routers ... he dead firmware, i had restores. something like this ... ;)
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RT3052 - it is used in routers ... he dead firmware, i had restores. something like this ... ;)
Ok.
By the way this has something to do with the SDS series?
(http://radiokot.ru/forum/download/file.php?mode=view&id=119208)
http://radiokot.ru/forum/viewtopic.php?f=10&t=70052&sid=f0c6b067c1522483e9cfb701355c613d&start=20 (http://radiokot.ru/forum/viewtopic.php?f=10&t=70052&sid=f0c6b067c1522483e9cfb701355c613d&start=20)
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"tinhead" You say" I don't want to be human!" I say you are a machine.
Did you find the BSDL model for S3C2416?
sure, i've posted one some time ago here in forum, but take better the attache version (in org. Samsung BSDL there was an error)
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"tinhead" You say" I don't want to be human!" I say you are a machine.
Did you find the BSDL model for S3C2416?
sure, i've posted one some time ago here in forum, but take better the attache version (in org. Samsung BSDL there was an error)
Thank you very much, but what do you mean with "in org. Samsung BSDL there was an error"?
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In addition, Samsung provides access to documentation and developer tools of processor on a separate individual agreement.
that's not a big deal, there are others who have all the docs.
Finally, for the firmware via JTAG need to have the image of ROM, which can not be obtained from the update FW.
that's right, you have to have full nand dump (which i have but can't provide as it does contains seril number as well).
Even if i would give you only the boot loader (which would allow to connect to PC and run fw update), your DSO would still not run as firmware update does not contains all files.
I'll send the oscilloscope on the warranty, if I am sure that the problem is in the software.
that would be the best you can do
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Thank you very much, but what do you mean with "in org. Samsung BSDL there was an error"?
the original Samsung BSDL file for S3C2416 contains such port definition:
PEINT[0] : inout bit;
however not all tools can work with "[" or "]", they crashing or not accepting such BSDL. Attached version
is using follwing instead:
PEINT_0 : inout bit;
which is valid for tools i'm using ("JTAG Probe" and "Universal Scan").
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Thank you very much, but what do you mean with "in org. Samsung BSDL there was an error"?
the original Samsung BSDL file for S3C2416 contains such port definition:
PEINT[0] : inout bit;
however not all tools can work with "[" or "]", they crashing or not accepting such BSDL. Attached version
is using follwing instead:
PEINT_0 : inout bit;
which is valid for tools i'm using ("JTAG Probe" and "Universal Scan").
Ok, now I understand. You've replaced all the ports.
I've only used "TopJTAG Probe" and "TopJTAG Flash Programmer" with the hardware "Bus Blaster v4.1a" as "JTAGKey" clone. It run with a TCK freq. of 15MHz Max..
I'm not sure if with this HW (JTAGKey) I could make a NAND backup. In theory, yes:
http://www.arm.com/community/partners/display_product/rw/ProductId/2232/ (http://www.arm.com/community/partners/display_product/rw/ProductId/2232/)
http://www.arm.com/community/partners/display_product/rw/ProductId/2255/ (http://www.arm.com/community/partners/display_product/rw/ProductId/2255/)
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....
that would be the best you can do
Yes, absolutely. I still think that there is a hardware failure...
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Any progress? Have you contacted Owon? Hope you can get your scope repaired! :)
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This is ver 3.3
https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/?action=dlattach;attach=57004;image (https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/?action=dlattach;attach=57004;image)
I have some news about adapter Version 3.3.
As we know the only difference of version 3.3 vs 3.2 was the 1000pf smd capacitor at the legs of capacitor C34 (opposite side).
There is one more change to version 3.3 2013.05.27, they routed the output of LCD Backlight on the adapter and made off the external cable for this purpose.
As you can see at the attachments photos, there is no any J1 socket. I have marked with the red arrows the new routed paths on pcb, but attention this routed there is no on tft cable to ours older scopes!
For this reason there are two options possibility: the first one is to changed the tft flat cable but I don't know if this could be or if this is available, the second one is to modify the U12 position and attach the old cable.
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Last time I get these boards as spare part from Owon there was also couple of J1 connectors attached. (need self solder).
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Rf-loop, were these boards routed on pcb with the LCD Backlight control?
In this situation what is better, to solder another socket on J1, or to find a new flat tft cable and change it?
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It looks like all the necessary connections for J1 are present. Owon probably designed the board for scopes with the new TFT cable as well as for scopes with the J1 cable. However, they may have recently decided to stop attaching the J1 connector because all the scopes in production have the new TFT cable. I think the only difference is that with the new TFT cable you get the filtering effect of the large flat ferrite. On my scope I have a small ferrite on the J1 cable.
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Exactly, I have the same opinion TomC.
As you can understand, just they arrived to me and the first mod done!
Here the new gnd_noise tests with the new psu and adapter board. The range of each measurement is marking on the title.
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Exactly, I have the same opinion TomC.
As you can understand, just they arrived to me and the first mod done!
Here the new gnd_noise tests with the new psu and adapter board. The range of each measurement is marking on the title.
Those are fantastic results! :-+
Congratulations!
I still have the old PSU inside my scope and I took the time to do some checks on my new PSU. AS far as L2 is concerned, it produces nearly no field or noise at all, as opposed to the old PSU where as you know I replaced it with a toroid. T1 is a different story, I found it to produce a stronger field than the old PSU and some noise was apparent on D2's heat sink. So I decided to try a belly strap and that reduced the field and noise some. I haven't tried it inside the scope yet. But the GND-noise was very low any way.
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Thanks TomC.
The L2 is different on the new psu vs mine old psu. I am quite sure that all these observations that we have done on this scope, the people of Owon knows that and improves them to the next version.
One of them is L2 inductor.
I am curious if the belly strap will effect to lower gnd-noise.
Am I wrong or the new psu has more temperature produce?
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Thanks TomC.
The L2 is different on the new psu vs mine old psu. I am quite sure that all these observations that we have done on this scope, the people of Owon knows that and improves them to the next version.
One of them is L2 inductor.
I am curious if the belly strap will effect to lower gnd-noise.
Am I wrong or the new psu has more temperature produce?
I checked the temperature and it was around 45C without the belly strap and 48C with the belly strap. So for some reason the difference seems to be less than what I measured with the old PSU. I want to do some more checks before I try it inside the scope, but I've been busy with a couple other projects and haven't had the time to do it yet. I'll post some comparison captures as soon as I do.
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At this point, I would like to mention the Aidetek and specifically the member ebayID smtzone for the completly warranty coverage of my scope to ground noise issue.
I had a contact with the Aidetek (smtzone was my dealer) for this issue and Aidetek contacts with Owon about this.
Finally, they send me the above new psu and adapter board free (under warranty coverage) and my only charge was the $15US for shipping.
Thanks again for this support.
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This is a positive development! :-+
As far as I know you are the only member with an older scope that got warranty coverage for this issue. Although it took some time, Owon's & Aidetek's response will surely be welcomed by their customer base. Let's hope that other users with similar problems will now get their problems acknowledged and fixed under warranty. If this happens, I believe it will be a win, win, for Owon's customers as well as Owon itself and the dealers like Aidetek that are taking a more responsible approach to their customer needs.
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I just got my Owon 6062V. It has vga+lan+both usb connections. It looks really nice and the display is top notch. Date serial is 1330 so it's pretty new and firmware version 3.4 but I have a problem with it |O . Whenever I do the self calibration it freezes on me. I tried to wait for 15 minutes but nothing happens. Also there's a note before saying that I can exit calibration any time by pressing any key but that doesn't work, since it actually freezes with only one progress bar. I can hear a relay and then nothing happens. Is there any way that I can do a hard reset on this thing or maybe rewrite the firmware? I can't find it anywhere thou. :-//
p.s. I added the pass/fail counter and it seems that that is working while the first calibrate bar is froze into place. Also I can't get it to trigger properly, it's random triggering and I have a lot of stuff going on while active, and can't stabilize the image.
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From what I saw at the site of Owon, there is no any available fw for your s/n to rewrite the fw.
Please make a contact with your dealer or the Owon Support (http://www.owon.com.hk/contact_l.asp (http://www.owon.com.hk/contact_l.asp)) about this.
Maybe they send you a fw to try to rewrite it.
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Normally rewrite FW do not help. FW integrity is tightly controlled and if there is FW data corrupted it normally do not run. There is quite good check sum etc. (This is not microsoft PC windows what can corrupt and so on.. )
Go to "Utility" and there "adjust" but do not press selfcal... press "default".
Wait 10-15 seconds. Shut off. After then power on.
Keep it running least 10 minutes. (real accurate selfcal need do after 30min power on)
Be sure you have not connected anything to scope exept power cable. Just all connectors empty. (it means also probes even if probe tip is not connected to anywhere. Input connectors NEED be exactly empty. (becouse all cal signals are routed (internally) via input BNC so that it use full signal pathway starting from BNC center pin.)
Go to "Utility" menu "adjust" and start "selfcal"
(It start with empty progress bar and if all ok it slowly progress)
During selfcal do not touch inputs.
In Owon it is quite slow. It do lot of front end cal procedures and trigger cal procedures etc.
If it do not newer go to final there is hardware problem.
If it go to final this phase is ok.
If it never go to final (wait enough time!)
Shut off scope.
Restart it.
Go to Utility menu and set default settings.
Connect probe to CH1. Turn probe to 1x
Connect probe tip to probe cal output and GND wire to probe comp out GND (do not short circuit comp output)
Also in scope CH1 menu select probe setting 1x if it is not.
Push then "Autoset" button.
Do it show triggered stabile 1kHz square?
If not (something is perhaps wrong) then watch what level is trigger mark (vertical level of trigger. It need be somewhere between centerline and top line. (becouse your signal is DC from center line to 5V.
If squere wave is untriggered you still can see its level around. Is this trigger mark around half way signal level.
Push "set to 50%" button. Notice if trigger level change anything.
Is it now triggered (steady 1kHz square visible top half area of display) or still untriggered.
Tell me how this trigger level is in these steps (you can see numeric value and also trigger level mark on the right border of screen..
1. After autoset, and 2. after set to 50%.
Also tell what is CH1 input level setting (what level autoset have selected for CH1 V/div)
Also tell what horizontal speed autoset have selected (time/div)
There is also trigger frequency counter window what show frequency (bottom right area of display). What is reading there. Is it steady and around 1kHz?
Do not try any FW upgrades in this phase. Only if Owon repair service give some FW and instructions for try some help or diagnose purpose.
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I decided to take it apart :box:
Everything went nice. There's no more plastic box replacing the actual battery. I have only a straight piece of plastic held in 2 screws. Guess their cutting their costs.
Power button went out nicely.
I attached some pictures of some components and issues I found inside.
I noticed a funny wire on the bnc connectors board so I decided to disassemble everything. There's no fan inside the 6062!
Aflter I got everything out I saw what that wire was. It seems they decided to make another connection inside, they disconnected one resistor near the 1khz source and instead of grounding it they routed the connection to another place via that wire, finally the connection goes into a chip. Also where they patched the other end near the chip...that connection was going to a via near the USB connector. They broke the connection to that via as well. I noted it in the photo. I don't know why they did this. Maybe a design error or they decided that this is better? That resistor is 1k and comes of that regulator or whatever that is near the 1khz source.
Then there's the adapter board connector, seems like some solder is missing on the top part, but on the bottom everything seems ok. Also that connector doesn't go all into the other board. it's partially in but I measured and there's electrical connection from one side to the other. I haven't found anything obvious apart from that wire.
Also I'd like to know what are the exact voltages that I should find on the PS conenctor? I found in order GND / GND / 8.48VDC / 8.48VDC / -7.86VDC / GND / 8.6VDC / 1.77VAC. There was an offset of 2.2mV between first grounds and the third.
The only "mystery" would be the metal plate that sits on top of the BNC board (not the one on the back). It's a very tight squeeze and it has a plastic sheet coming out, I presume to provide electrical shield between the metal shield and the electronics inside. It's not quite centered as well and it's soldered so I did not touch it. I could void my warrany this way and I just got a broken scope :rant:
After I partially assembled it I decided to start it up and see what's happening. Maybe if I wiggle some parts it will work. Started right up and I had the probe connected to the 1khz source and it seemed smooth. The waveform was on screen and the trigger button was green. I decided to start the calibration once more and hurray! it worked, in a few seconds it made the whole adjustment. After maximum one minute of playing with the knobs the red light appeared on the Run/Stop button and nothing worked again. It froze again when I selected the self calibration... So it seems that it's either a thermal character or something is not touching right. I didn't screw anything tight. I will try to play some more maybe I find the problem. I will put a fan to blow inside, maybe that would help as well. Any more ideas? :-BROKE
I forgot to mention that when the scope is not working there's red light usually on the Run/Stop button. If I press it it goes red again instantly. When it worked that button was green.
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For some reason the insides of that unit fill me with horror. I think it's the worst I've seen so far.
Anyway, your pinout for the adapter board PSU connector is bad. There are two grounds, two positive voltages, one negative voltage, two control lines for the bi-color 3 mm LED above the F1 key and AC signal for AC power line trigger. Some pages back, we've had schematics of two PSU versions. Positive voltage is 8.4 V and negative voltage is -7.6 V. When the scope is running from the battery, the 8.4 V is provided by the battery. All other voltages are derived from the 8.4 V line. On the bi-color LED, green is shining when there is AC power and red is shining when the battery is being charged.
The box is the actual battery case. The only difference is that the real battery actually has cells inside of the box. They've been using a panel instead of the box at least since mid 2012.
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Well I think I found the problem but no way to fix it.
I connected all the parts out of the casing and fired it up. It worked good for a while then I started moving the parts to see the problem. I could only make it work then if I bent the main pcb. Seems like there's a connection fault somewhere on the board but I don't know where. I pushed all the chips but no change, but if I twist and bend slightly the whole board there are some positions in which the auto calibration works perfect and I get the test signal on screen. Maybe an internal layer problem or something.
When I started assembling the whole scope together I found the problem. The main board locks into place with 4 screws into metal legs that are attached to the main plate. The upper right corner metal leg si off-place by 1 mm or so. When I tried to install the screw I had to push the metal leg inwards so the screw could get in. That tension might have broken the board. I added a photo of the culprit. If there's anyone that lost his warranty and wants to make sure then open it and check that the main PCB sits freely on those metal legs and no tension is applied to it. You can leave out that screw for safety, the board is snug with only 3 screws. I will have to air-mail my unit back to the store where I got it from and then wait for them to get another unit etc... Lost time :-BROKE
These are nice units, if they work out of the box, with no problems! I don't recommend this company, but maybe they make up with customer support.
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The 1K resistor mod doesn't look very professional. :palm: I wonder if this was an attempt at the factory to repair the problem you are having now. The problem may have temporarily disappeared after the mod and they may have thought it was fixed.
Hope that you have better luck with the replacement unit! :)
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It would be interesting to know if there are any other 6062 units like that. Especially the newer ones since they may have implemented that "fix" in the later units.
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Uhh, we could tolerate some hardware bugs if this scope was from the beginning of production. But this SDS6062 scope is made in 2013 while the production started in January 2011 or so...
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Hello all.
I have a problem with inverted signal in my SDS7102V. Firmware version 3.2. More details on OWON SDS7102V problem with inverted signal (https://www.youtube.com/watch?v=okPBFhW4Qn4#)
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The same is here, but I think is normal.
I can't to explain you, how this trick works, it's something like tranzistors dc-offset function. It likes as demonstrated 0:49-0:52 of the following video.
NJARC Oscilloscope School a.k.a. "Scopes For Dopes" (https://www.youtube.com/watch?v=8ZKMrzTGxLQ#ws)
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No, I don't agree. It is not normal. On your video showed work of transistor. I don't change the parameters of entrance signal, and only change vertical position of signal. On input a meander is given from oscilloscope.
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inlet,
I notice the same behavior on my SDS7102, so this doesn't seem to be a malfunction on yours. On mine the behavior is worse with DC coupling. I also noticed that the behavior improves after doing a self calibration. Is this the case with yours too?
I think this is some kind of firmware oddity, I didn't notice it before you brought it up, so evidently is not something that affects my everyday use of the scope. Is there a particular application where this affected the usability of your scope?
It wouldn't hurt to make Owon aware of this bug, perhaps they can address it in an upcoming firmware release!
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I don't know if my SDS8102V has the same fault. I don't even use it and now is completely disassembled.
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Calibration does not help. Found a problem, when I checked up an inverting amplifying cascade(compared an entrance and exit).
Support of OWON said: "Please contact the seller, they will help you to upgrade the firmware".
Another video, but with sinus signal.
OWON SDS7102V problem with inverted signal - part2 (https://www.youtube.com/watch?v=ac0XHukKpr0#)
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Is there a particular application where this affected the usability of your scope?
Hi, you'll definitely meet the problem with math A+(-B) function etc.
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inlet & Evi
I recently checked the Owon site and the latest firmware is 3.2/3.3 , which is what you have on your scope and is also what I have on my scope. So as far as I know there is no newer release that can help with this problem. I have used the math functions occasionally and had not noticed this problem, but as I said before, after you brought it up I was able to duplicate the behavior. So there is no doubt in my mind that the problem is real! Have you sent to Owon a copy of the videos? As I understand it, they are not able to access YouTube from China. So, for example, you could attach the actual video to the e-mail.
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I really have the desire to do a ritual, and throw it into the fire. >:D
I put it for sale, and nobody wants it, and no wonder. :palm:
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inlet & Evi
Have you sent to Owon a copy of the videos? As I understand it, they are not able to access YouTube from China. So, for example, you could attach the actual video to the e-mail.
Last year I sent to Owon support a lot of pictures with videosync bug. They hardly promised to fix it. Till now no results as I know. So, I returned Owon back to seller and switched to Rigol.
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No returns allowed by Aidetek...
And yes, I try to return it after a few days of receiving.
Note: If anyone wants a SDS8102V, is yours for 300€.
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Not sure if anyone's encountered this problem before, I looked for a bit through this thread, but couldn't find it. Sorry if it's already been mentioned.
I have noise on channel 1 that reads about +60-100mV on 5V/div.
The noise is proportional to the V/div (e.g. 1V/div gives 12-20mV of noise), and it wanders constantly between two values, which suggests two things:
- the noise is just before the ADC, and after input scaling circuitry
- the noise is not only AC, but it contains a DC offset, suggesting that something in the scaling circuitry output or ADC input is poorly tuned, and some other AC noise exists that is causing the wandering
If anyone has any pointers, it'd be very much appreciated.
EDIT: forgot to mention, I've tried self-calibrating, rebooting, using a different probe (with GND clip connected to probe tip), removed the probe, tried compensating the probe. Even measuring the 5V square wave test signal gives me the same noise on channel 1. :-//
Cheers,
David.
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I didn't know that China has a problem with YouTube. Today send e-mail with actual video files.
Please, who has OWON oscilloscope with such problem, send to support of OWON also.
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Not sure if anyone's encountered this problem before, I looked for a bit through this thread, but couldn't find it. Sorry if it's already been mentioned.
I have noise on channel 1 that reads about +60-100mV on 5V/div.
The noise is proportional to the V/div (e.g. 1V/div gives 12-20mV of noise), and it wanders constantly between two values, which suggests two things:
- the noise is just before the ADC, and after input scaling circuitry
- the noise is not only AC, but it contains a DC offset, suggesting that something in the scaling circuitry output or ADC input is poorly tuned, and some other AC noise exists that is causing the wandering
If anyone has any pointers, it'd be very much appreciated.
EDIT: forgot to mention, I've tried self-calibrating, rebooting, using a different probe (with GND clip connected to probe tip), removed the probe, tried compensating the probe. Even measuring the 5V square wave test signal gives me the same noise on channel 1. :-//
Cheers,
David.
There was an issue with noise on CH1 on scopes built around 2011. If your scope falls into this category take a look at this link:
https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/msg79361/?topicseen#msg79361 (https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/msg79361/?topicseen#msg79361)
It has to do with replacing a metal pillar to a plastic pillar to correct the problem. You can search using "pillar" as the keyword for other posts on this subject.
Good luck! :)
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I didn't know that China has a problem with YouTube. Today send e-mail with actual video files.
Please, who has OWON oscilloscope with such problem, send to support of OWON also.
Hi inlet and everyone.
I have SDS7102V and i have same problem with inverting channel. My version is 3.0.
I realized what is the point. Scope is doing invert of wave shown on the screen. So, if the waveform is moved up, and cut with the edge of the screen, inverted waveform will be cut also.
So, as long as whole waveform is on the screen invert will be correct, otherwise invert will be cut.
This may help owon to fix this problem.
Here is short video about this. https://www.dropbox.com/s/gzstblo60y50d7z/2013-11-07%2000.02.43.mp4 (https://www.dropbox.com/s/gzstblo60y50d7z/2013-11-07%2000.02.43.mp4)
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True, I also noticed that if you change the Time/Div setting the waveform returns to normal. Nevertheless, it is an annoying bug that ought to be fixed in my opinion. I guess I seldom move the waveforms outside of the screen confines, so it never bothered me before. For waveforms other than square waves is not difficult to detect that the scope is giving you a false reading. However, now that I know this happens, I feel I need to be extra careful when measuring square waves.
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I didn't know that China has a problem with YouTube. Today send e-mail with actual video files.
Please, who has OWON oscilloscope with such problem, send to support of OWON also.
Hi inlet and everyone.
I have SDS7102V and i have same problem with inverting channel. My version is 3.0.
I realized what is the point. Scope is doing invert of wave shown on the screen. So, if the waveform is moved up, and cut with the edge of the screen, inverted waveform will be cut also.
So, as long as whole waveform is on the screen invert will be correct, otherwise invert will be cut.
This may help owon to fix this problem.
Here is short video about this. https://www.dropbox.com/s/gzstblo60y50d7z/2013-11-07%2000.02.43.mp4 (https://www.dropbox.com/s/gzstblo60y50d7z/2013-11-07%2000.02.43.mp4)
Exactly, it seems like the processor keeps all the information that be into the screen and all other rejected .
Have anyone knowledge, how is implemented by other DSO scopes?
Have any respond from the Owon's support, about this?
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Have any respond from the Owon's support, about this?
Owon's support promised for 4 weeks to produce the new firmware.
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To see what I see ... about this.
The last 6-8 months Owon stopped give us new releases for fw, unfortunately.
Many people believed that there will be a new release with extra functions (that they missed), but this release never came. I hope to be to this release.
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If nothing else, I would love to see this issue with the invert fixed. Anything else would be icing on the cake! 8)
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I have probelm with FFT, everything is described on this forum http://owon.forumup.com/viewtopic.php?t=216&mforum=owon (http://owon.forumup.com/viewtopic.php?t=216&mforum=owon)
What you think about this? Should i report this to owon?
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We had some feedback on this a few weeks ago right around the following post:
https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/msg307365/?topicseen#msg307365 (https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/msg307365/?topicseen#msg307365)
I still think this is inconvenient, and I still don't know how this is implemented on other DSOs. It would be nice if the two functions (FFT & waveform) were independent. However, I don't think we can call this a malfunction, as in the case of the invert bug. So if you want to report this to Owon, I would approach it as asking for an improvement in the firmware and see if they are responsive.
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New Oscilloscope PC Software version 2.8.20 from the Owon's main site.
No any reference for improvements about, no any changed log.
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I noticed the Splash Screen is different, Owon instead of DS-Wave. Other than that, I haven't detected any changes so far.
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TomC have you tried the remote lan behaviour?
I don't undestand the point of this fw. If you see the previous numbering was 1.0.18 and now is 1.0.20
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TomC have you tried the remote lan behaviour?
I don't undestand the point of this fw. If you see the previous numbering was 1.0.18 and now is 1.0.20
I hadn't checked the remote LAN until today. I don't see any improvement. It causes the scope to freeze often, specially if you use the up/down controls for the vertical divisions or the trigger voltage while in RUN. This is not a problem when using the USB. Also the SCPI command line gives you a receive error when you try to use it, then the scope freezes when you close the window. Again, this is not a problem with the USB. The only positive thing I found is that high memory depth seems to work better when the acquire length is 10M. Before, I would always end up with the scope freezing. However, when I re-tried it today with the old version (2.0.8.17), it worked just as good. So I don't know if installing version 2.0.8.20 updated some common component that is also now used by the 2.0.8.17 version, or some other change in my system caused the improvement. Who knows! The main point is that in its current state remote LAN is pretty useless in my opinion.
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Ok, now I understand. You've replaced all the ports.
I've only used "TopJTAG Probe" and "TopJTAG Flash Programmer" with the hardware "Bus Blaster v4.1a" as "JTAGKey" clone. It run with a TCK freq. of 15MHz Max..
I'm not sure if with this HW (JTAGKey) I could make a NAND backup. In theory, yes:
Carrington,
Few month ago tinhead's description of JTAG pins was sufficient for me to make a full flash backup. I've used H-JTAG software.
Most recent H-JTAG has support for S3C2416 and the flash chip.
But when I did this it has become evident to me that this action is excessive for my purpose (my scope had only chineese menu language and I wanted to enable full langpack).
Because Owon's factory upgrade tool can do more than documented in the upgrade manual.
Upgrade tool (launcher.exe) is 100% java software and can be easily de-compiled back to source code.
Owon's firmware is encrypted while in storage. But the encryption key is included in the zip. (public.key)
One of the upgrade tool's command line modes is 'launcher.exe encrypt'. This helps to encrypt and decrypt firmware files (tx, os, fp, me, help,...) in both directions.
In order to submit a single file into the scope 'launcher.exe usbpatch' command line is in use.
My experience is explained in a little bit more details here:
http://radiokot.ru/forum/viewtopic.php?p=1526909#p1526909 (http://radiokot.ru/forum/viewtopic.php?p=1526909#p1526909)
and here:
http://radiokot.ru/forum/viewtopic.php?p=1725552#p1725552 (http://radiokot.ru/forum/viewtopic.php?p=1725552#p1725552)
Because it is in russian, you will need to use any online translator.
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Ok, now I understand. You've replaced all the ports.
I've only used "TopJTAG Probe" and "TopJTAG Flash Programmer" with the hardware "Bus Blaster v4.1a" as "JTAGKey" clone. It run with a TCK freq. of 15MHz Max..
I'm not sure if with this HW (JTAGKey) I could make a NAND backup. In theory, yes:
Carrington,
Few month ago tinhead's description of JTAG pins was sufficient for me to make a full flash backup. I've used H-JTAG software.
Most recent H-JTAG has support for S3C2416 and the flash chip.
But when I did this it has become evident to me that this action is excessive for my purpose (my scope had only chineese menu language and I wanted to enable full langpack).
Because Owon's factory upgrade tool can do more than documented in the upgrade manual.
Upgrade tool (launcher.exe) is 100% java software and can be easily de-compiled back to source code.
Owon's firmware is encrypted while in storage. But the encryption key is included in the zip. (public.key)
One of the upgrade tool's command line modes is 'launcher.exe encrypt'. This helps to encrypt and decrypt firmware files (tx, os, fp, me, help,...) in both directions.
In order to submit a single file into the scope 'launcher.exe usbpatch' command line is in use.
My experience is explained in a little bit more details here:
http://radiokot.ru/forum/viewtopic.php?p=1526909#p1526909 (http://radiokot.ru/forum/viewtopic.php?p=1526909#p1526909)
and here:
http://radiokot.ru/forum/viewtopic.php?p=1725552#p1725552 (http://radiokot.ru/forum/viewtopic.php?p=1725552#p1725552)
Because it is in russian, you will need to use any online translator.
I'm watching all now, thank you very much. Let's see if I can translate.
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@ kptn
Good job, finally you enabled the full langpack.
I load the SDS8202V's firmware on my SDS8102V, modifying this file (is very easy):
x:\Program Files\OWON\Patch\config.xml
It works perfectly, but is necessary to change the serial number, to enable SDS8202V's features (BW). But the funny thing is that the windows PC SW oscilloscope identifies it as a SDS8202V.
The Owon input stage supports more than 200MHz, the limit is only imposed by the LMH6518, so would be interesting hack it.
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I've only used "TopJTAG Probe" and "TopJTAG Flash Programmer" with the hardware "Bus Blaster v4.1a" as "JTAGKey" clone. It run with a TCK freq. of 15MHz Max..
I'm not sure if with this HW (JTAGKey) I could make a NAND backup. In theory, yes:
First:
My S3C2416XH-40 (KS88C0216) device Id. is: 00000111100100100110111100001111 (0x0000000007926F0F). It does not match with the BSDL file posted here.
I tried modifying the id. in the bsdl file, but does not work. And I can't find the correct BSDL file for this processor.
Second:
TopJTAG does not support this type of NAND (S29GL-P MirrorBit).
So, for the moment, I can't do a NAND dump.
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the BSDL file is ok, simply don't care about the ID.
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the BSDL file is ok, simply don't care about the ID.
Yes, no doubt. But I need other software to make a dump.
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But I need other software to make a dump.
TOP JTAG Flash works only for CFI/NOR memory, not NAND. I'm using here H-JTAG, as it does support both the SoC and NAND.
If you don't want spend money for H-JTAG USB (USD159 + shippment) you can still build LPT wiggler and let run the H-JTAG flasher for a day or two - and you will get dump of NAND as well. How to build such LPT wiggler has been describen in the H-JTAG software help file.
Any FTDI based wiggler (so ARM wiggler) and openocd should work as well (i have here only setups, schematics, tools for S3C2440 and smaller NAND, so not useful for you, but goodle is your friend)
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TOP JTAG Flash works only for CFI/NOR memory, not NAND. I'm using here H-JTAG, as it does support both the SoC and NAND.
If you don't want spend money for H-JTAG USB (USD159 + shippment) you can still build LPT wiggler and let run the H-JTAG flasher for a day or two - and you will get dump of NAND as well. How to build such LPT wiggler has been describen in the H-JTAG software help file.
Yes, I'm on it.
I'm thinking about using a USB-LPT based on a CH340 chipset.
(https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/?action=dlattach;attach=69303;image)
(https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/?action=dlattach;attach=69306;image)
Any FTDI based wiggler (so ARM wiggler) and openocd should work as well (i have here only setups, schematics, tools for S3C2440 and smaller NAND, so not useful for you, but goodle is your friend)
Don't worry, I might end selling it.
Thanks. :-+
for a day or two
Woow, very slow. :=\
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I have got lost touch with this thread, what are you guys trying to do?
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I have got lost touch with this thread, what are you guys trying to do?
I want more BW.
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I have got lost touch with this thread, what are you guys trying to do?
If I remember correctly, someone took the time to go through the firmware update package and found out how to decrypt the firmware for the scope. Right now, they seem to be trying to get some more firmware dumps from the scope itself to compare with data in the firmware (maybe?). There's a suspicion that the 2 GSa/s model has software-controller bandwidth, so it may be worth hacking it.
There's been a big pause in this thread, so for the newest topic of interest, only the last two pages are relevant.
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Ah ok so this does not apply to the SDS7102 which is in the title of this (very long) thread?
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I'd say that it does, but in an indirect way. You see, my perception is that they're building a base for firmware hacking for the whole series. While the current goal of Carrington for example may be to increase the bandwidth of his scope, results would be useful for any other further firmware hacking.
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I'd say that it does, but in an indirect way. You see, my perception is that they're building a base for firmware hacking for the whole series. While the current goal of Carrington for example may be to increase the bandwidth of his scope, results would be useful for any other further firmware hacking.
Exactly that's. At least, I want to try.
Custom firmware?
https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/msg64492/#msg64492 (https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/msg64492/#msg64492)
(https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/?action=dlattach;attach=69332;image)
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I thought the 1Gb/s limit was the ADC + clock frequency and did I read somewhere that if you use two channels it drops to 500Kb/s because of something shared or something?
In other words I had thought the SDS7102 has a hardware limit to 1Gb/sec.
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Correct, but the SDS8102 is 2GB/s, different ADC scheme. I don't think the intent here is to change the sampling rate. However, this hardware sampling rate is sufficient to properly represent input frequencies beyond 100MHz. So if the input BW can be increased, the 2GB/s scope can be usable at perhaps 300MHz.
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For those who have the SDS7102 however the hard limit is 1Gb/s ?
How many samples per cycle are absolute minimum to display a meaningful 100MHz curve? I'd say 2 at least, hoping we'd hit the top and the bottom, and many more if we want to display a sine rather than a triangle?
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Whoa there, don't make such dangerous assumptions about those ADCs. The ADC types in SDS7102 are two channel 500 MB/s (that's real MB/s, not MiB/s) units, which can be set to work as single channel 1 GB/s unit. These aren't Gb/s or kb/s ADCs! I've heard of research in very high speed sigma-delta ADCs which could in theory be used for imaging or datacapture with just one bit, but we're not close to having them in our "simple" oscilloscopes.
Next, in order to get relevant data, for 100 MHz sine wave with bit depth of 8 bits per sample, we need rate of 200 MB/s. This is due to the type of interpolation used, namely the sinc(x) function. The downside of this calculation is that we can get some pretty big problems if for example the start of the signal and the start of our sampling period aren't correctly matched. Basically, we need two correctly placed data points to use sinc interpolation to get a sine wave. I'm not sure how much points we'd need exactly, if there's a mismatch. It should be fun to calculate, so I'll try to get some results and graphs one of these days.
For a triangle, we'd definitely need even more data than we'd need for the "simple" sine wave. I'll try to make some experiments with that too, but I can't make any promises.
The SDS8000 series uses a two channel, 1 gigasample per second ADC, which can be set to work as single channel 2 GSA/s ADC.
In any case, on paper, SDS7102 should be capable of showing data with no aliasing up to 500 MHz and 8000 up to 1 GHz. I did use my SDS7102 go look at spectrum from DC to 500 MHz and the data looks OK, expect of course the high frequencies are severely attenuated. I could make out lower VHF TV channels though. I'll post a picture as soon as I dig it up.
This leaves us with the sample rate=bandwidth*10 rule of thumb, which would be violated in case of bandwidth increase. How big of a problem that would be, I'll leave for someone else to answer :).
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I thought the 1Gb/s limit was the ADC + clock frequency and did I read somewhere that if you use two channels it drops to 500Kb/s because of something shared or something?
In other words I had thought the SDS7102 has a hardware limit to 1Gb/sec.
Highly summarized:
- For real time sampling acquisition and bandlimited signal: Fs > 2Fmax.
Now use common sense: Everything depends on the details that you want (I'm not talking about ADC dynamic range), more details -> more frequency components -> more BW, then -> more Fs.
i.e.: The sampling rate must also be sufficient for an acceptable reconstruction of the signal, for example a square pulse.
- For equivalent time sampling acquisition and only periodic bandlimited signal, then Fs can be less than signal's BW. But I think that this is not the case.
An interesting document (211 to 236) [220]:
http://w140.com/Handbook_of_Oscilloscope_Technology.pdf (http://w140.com/Handbook_of_Oscilloscope_Technology.pdf)
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If you don't want spend money for H-JTAG USB (USD159 + shippment) you can still build LPT wiggler and let run the H-JTAG flasher for a day or two - and you will get dump of NAND as well. How to build such LPT wiggler has been describen in the H-JTAG software help file.
tinhead, that's correct.
As an example, I've already told that I've used this http://item.taobao.com/item.htm?id=10448149057 (http://item.taobao.com/item.htm?id=10448149057) wiggler to dump the image of my SDS7102. Wait time was not critical for me - I prefered to buy a device for few bucks instead of soldering it for few hours.
H-JTAG sofware were good enough to access the flash. I don't know if it works with USB-LPT converters, I've used old PC motherboard with LPT port built-in.
Full flash read of the scope took me 6-7 hours. H-JTAG were able to show read performance in advance, so I just left in running for full night.
Tinhead, thank you as well for analysis of the flash dump you've made on this thread two years ago. I've used it to get my tx file (calibration data).
Unfortunately, I did not succeed with Yaffs stuff - no one of public Yaffs readers I've tried were able to give me flash content.
Finally, I took my tx from raw image.
When looking at the flash dump I was surprised that each firmware upgrade been made takes a portion of the flash free space. So once upon a time the scope may reject you to perform next upgrade when the space will be exhausted!
This means that we probably should avoid to upgrade the device unless we actually want to use a specific new feature that comes with this particular upgrade.
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This leaves us with the sample rate=bandwidth*10 rule of thumb, which would be violated in case of bandwidth increase. How big of a problem that would be, I'll leave for someone else to answer :).
Highly summarized:
- For real time sampling acquisition and bandlimited signal: Fs > 2Fmax.
Now use common sense: Everything depends on the details that you want (I'm not talking about ADC dynamic range), more details -> more frequency components -> more BW, then -> more Fs.
i.e.: The sampling rate must also be sufficient for an acceptable reconstruction of the signal, for example a square pulse.
For sin(x)/x interpolation, a sampling rate of 2.5x the highest frequency is considered good enough to faithfully reconstruct the signal from the samples. But sin(x)/x is highly susceptible to errors if the original signal contains frequencies higher than the Nyquist frequency.
That is why the Rigol DS2000 series automatically switches from sin(x)/x interpolation to linear interpolation when the sampling rate <= 500MSa/s - because the Nyquist frequency starts to drop too low for reliable reconstruction. For example, @ 200MSa/s the Nyquist frequency is 100MHz - which easily passes through the BW filter.
When you use linear interpolation, it's cruder so it requires a higher sample rate ratio for faithful reconstruction (at least 8x, but 10x is considered the rule of thumb as AndrejaKo mentioned), but it won't introduce false peaks at slower sample rates like sin(x)/x might.
I'm not sure which (or when, if switching between them) interpolation scheme the Owon uses.
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Only as complement: pages 260-262 of the previous link.
Thanks marmad.
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Tinhead, thank you as well for analysis of the flash dump you've made on this thread two years ago.
you welcome
When looking at the flash dump I was surprised that each firmware upgrade been made takes a portion of the flash free space. So once upon a time the scope may reject you to perform next upgrade when the space will be exhausted!
This means that we probably should avoid to upgrade the device unless we actually want to use a specific new feature that comes with this particular upgrade.
oh that's ugly, i thought they using part as scratchpad, part as backup and part an live firmware.
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I bought the SDS7201 for $365.00 this past week. I rather like this scope, especially for the price. Plus it came with a free bag, and free shipping! Not a bad deal at all.
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Yeah, I noticed that special sale at Saelig. I bought mine from them last January, but I paid $429. At the time the scopes being shipped had the GND noise issue, so I had to spend extra money later on to upgrade the PSU. Luckily, the scopes being shipped now don't have that issue. Hope you enjoy your new scope. :)
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Thanks. I'm having a blast just learning.
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I didn't know that China has a problem with YouTube. Today send e-mail with actual video files.
Please, who has OWON oscilloscope with such problem, send to support of OWON also.
Hi inlet and everyone.
I have SDS7102V and i have same problem with inverting channel. My version is 3.0.
I realized what is the point. Scope is doing invert of wave shown on the screen. So, if the waveform is moved up, and cut with the edge of the screen, inverted waveform will be cut also.
So, as long as whole waveform is on the screen invert will be correct, otherwise invert will be cut.
This may help owon to fix this problem.
Here is short video about this. https://www.dropbox.com/s/gzstblo60y50d7z/2013-11-07%2000.02.43.mp4 (https://www.dropbox.com/s/gzstblo60y50d7z/2013-11-07%2000.02.43.mp4)
Have any respond from the Owon's support, about this?
Owon's support promised for 4 weeks to produce the new firmware.
Hi everybody.
No, Christmas cookies from Owon to us. There is no any fw update, until now.
Where is the Owon's support promised?
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New Oscilloscope PC Software version 2.8.20 from the Owon's main site.
No any reference for improvements about, no any changed log.
It is strange! As I am looking today for any software update in their site, it seems the same PC Software (2.8.20) with a new date of 12 Dec' 2013!
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Owon has done that before, same release number but different date. I seem to remember that in some cases the later date had new fixes/features. So will have to check and see if this is the case this time. It would be nice and much more professional if they would provide a summary of changes upfront. The way it is now is like solving a new riddle each time.
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Guys I sold my SDS8102V so goodbye forever OWON.
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:-+ Hope you'll still visit and reminisce!
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Guys I sold my SDS8102V so goodbye forever OWON.
What are you getting instead? I was about to buy one of these but I do not like the "Clicky" buttons!
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I forgot to tell you that I got my replacement SDS6062 (no V this time, I agreed with the seller as he had this on stock).
This unit worked very good, I had no issues with it. It served me well while repairing a Tektronix 465 scope that I got from ebay. The Tek had some issues at faster sweep speeds and with the help of the guys over at TekScopes Yahoo group and the Owon I could trace the problem to a bad transistor :)
I think I did the noise measurement when I got it and it checked out ok, it didn't show any extra noise than this price range digital DSOs might have.
And also, for basic measurements it seems OK. At least for a beginner. Overall I'm very happy with the product, I did lots of screenshots and it allowed me to see the main problems of my project so I'm not complaining.
I guess it's a decent tool for the money and I wouldn't expect stellar performance out of it but for most basic stuff it gets the job done with no major issues.
After the problems with the first unit I also decided to get a Tek 465 analog scope for backup and analog feel/work ^-^
I could recommend this to beginners as long as they buy it locally from a seller with good warranty support (and stock). It's the same thing with all the other chinese producs - you might get a dud or you might get a better spec (in some areas) than other reputable brands at lower price (larger screen, memory depth etc) but lousy quality. But hey, if it works it's a good deal :) This off course applies if you don't have the cash for something better or you want a larger screen with battery option and the ability of differential measurements if you don't have an isolation transformer (can be done with either two channel oscilloscope anyway but I don't know how precise). If you can afford it get an older analog oscilloscope for cheap off ebay (60-100Mhz) and a DSO. Both have their advantages/disadvantages. I can certainly appreciate the on screen measurements of the DSO 8)
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:-+ Hope you'll still visit and reminisce!
Sure! I will try to help with what I can.
Thank you very much for your support.
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Hey guys
I need a scope to write and analyze very long analog signal. I think SDS7102V with VGA port is exactly what I need for my 500 USD budget. But some old H/W revisions had GND noise problem. Where can I get this scope without any bugs, problems?
I asked this seller about serial number and firmware version, he replied:
Serial # is around SDS71021344421, firmware version is V3.2, we offer free firmware upgrade, thank you.
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=181185202887 (http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=181185202887)
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Hey guys
I need a scope to write and analyze very long analog signal. I think SDS7102V with VGA port is exactly what I need for my 500 USD budget. But some old H/W revisions had GND noise problem. Where can I get this scope without any bugs, problems?
I asked this seller about serial number and firmware version, he replied:
Serial # is around SDS71021344421, firmware version is V3.2, we offer free firmware upgrade, thank you.
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=181185202887 (http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=181185202887)
I've had min for quite some time now and been very happy with it, the large screen and overall performance is very satisfying. I think the noise issues were primarily on the earliest units, but I might just have been lucky in the Chinese budget oscilloscope lottery :) .. I got mine from Aidetek, possibly the same dealer as the one in your ebay link.
The best option would be to buy from someone you are confident will provide and honor a decent warranty period.
For slow measurements, the max time base is 100s/div, total 1500 seconds on screen.
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I'm asking here because on some(3.5?) h/w revision Owon fixed that bug with PSU GND noise. I' m choosing between SDS7102V and Atten ADS1102CML(1 Megasample memory depth).
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I'm asking here because on some(3.5?) h/w revision Owon fixed that bug with PSU GND noise. I' m choosing between SDS7102V and Atten ADS1102CML(1 Megasample memory depth).
As far as I know, the GND noise issue was resolved June of this year. Several members have bought scopes since then and had no issues. I bought my scope during January this year and ended up with the ground noise issue. After upgrading the PSU and some other mods everything is OK now. The serial number you were quoted is recent enough it should have the upgraded hardware.
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Anyone bought from Saelig? Do they sell buggy SDS7102V?
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Anyone bought from Saelig? Do they sell buggy SDS7102V?
I recommend you this site: http://www.silcon.cz/index.php?route=common/home (http://www.silcon.cz/index.php?route=common/home)
Is completely trustworthy.
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Anyone bought from Saelig? Do they sell buggy SDS7102V?
I bought from Saelig, at the time, like everyone else, their scopes had the GND noise issue. However, other than that, the product was delivered promptly and response to e-mails was fast. Recently they had the SDS7102V for $365, sort of a black Friday special. A member one page back bought from them and was very happy with his new scope.
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What is the most recent firmware version? What about serial numbers(let's say november 2013)?
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What about serial numbers(let's say november 2013)?
Is SDS71021319xxx? I don't remember, look at the last pages of this subject.
Read this:
https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/msg279444/?topicseen#msg279444 (https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/msg279444/?topicseen#msg279444)
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Hello,
I needed a knock around scope that had a battery powered option, so I bought one of the SDS7102V's from Saelig during their sale. Hard to beat at that price. I added the optional battery. It came with a free soft sided carrying case and the standard two 1X/10X probes. It has version 3.2 firmware (checksum 1DCC3238) and does not suffer from the noise issues noted by others.
It also does not suffer from the strange problems associated with zooming in and back out on a 10M single shot capture after stopping that my work SDS6062 has. I wish they would release a firmware update for that scope as well.
I have had the scope since last Thusday and although it's no LeCroy for $365.00 it is quite a good little scope. Sure it has some shortcomings as Dave has pointed out (many fixed in this newer firmware) but what do you want for 365.00! I would really like to have a quad trace version of this scope as an entry level scope.
I am guessing that Owon probably is coming out with a higher performance line and that is why these scopes are being blown out so cheap!
As far as the vendor have found that Saelig is a very good company and stand by their products.
Also they are a US supplier so you get the US warranty. It seems that their pricing is as good as anyone out there when you figure everything in.
All the best,
Sam
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Unfortunately Saelig can't ship the scope to Russia... By the way, SDS7102 costs around 650 USD in Moscow offline shop.
I think I would buy it on ebay or aliexpress. Should I also buy a battery?
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Unfortunately Saelig can't ship the scope to Russia... By the way, SDS7102 costs around 650 USD in Moscow offline shop.
I think I would buy it on ebay or aliexpress. Should I also buy a battery?
Well it depends. Will you be using it to debug high voltages? In that case, get a proper, isolated scope. Otherwise, if you just want to carry it around for use in the field, then yes, go for it. Otherwise put that money towards a good DMM or something else.
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I found EDS102C/V on taobao:
http://item.taobao.com/item.htm?spm=a230r.1.14.23.1mbuPl&id=13859092514 (http://item.taobao.com/item.htm?spm=a230r.1.14.23.1mbuPl&id=13859092514)
It's seems to be the same as SDS7102V. Am I right?
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It should be mostly same, but that version only has user interface in Chinese, as far as I remember. I'm not aware of any straightforward way to install western firmware on it, I think that is was possible. Someone wrote a story about that in this thread many many months ago.
As for the battery, I found it very handy when I needed isolated scope for low voltage use, such as scoping output of certain types of audio amplifiers. It's a bad, but easy way to avoid ground loops and can work with devices which use push-pull configuration. I had my scope since June 2012 and the battery run time is still within specification. Ultimately, you'll have to decide for yourself if it's worth spending money on the battery or not.
@scopeman
Yes, Owon already presented a new, more powerful, series on their website called TDS and we had a thread about it as well. As far as I can see, it still isn't available for puchase. There are currently 3 versions of it: 100 MHz with 1 GSa/s, 100 MHz with 2 GSa/s and 200 MHz with 2 GSa/s. It's supposed to have much higher screen update rate compared to SDS's 25/35 waveforms/s.
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So, I purchased SDS7102V on ebay for 430 USD. I could buy it on taobao for around 300 USD, but I never bought anything on taobao and I don't have chinese bank account/credit card to pay. Plus I have paypal buyer protection.
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So, I purchased SDS7102V on ebay for 430 USD. I could buy it on taobao for around 300 USD, but I never bought anything on taobao and I don't have chinese bank account/credit card to pay. Plus I have paypal buyer protection.
That's a fair price! :-+ Good luck! Let us know how you like it. :)
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Hi,
looking for 7102V and somwhere I read that is not possible to measure devices powered on same source as this DSO. It needs to be isolated. Is it still needs or it was for older Owons?
Thanks
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Hi,
looking for 7102V and somwhere I read that is not possible to measure devices powered on same source as this DSO. It needs to be isolated. Is it still needs or it was for older Owons?
Thanks
It depends. The reference point is not at the same potential as the reference of your oscilloscope? This applies for all, not just the OWON.
Never let the oscilloscope's reference as floating, never.
In case of doubt, uses galvanic isolation, on the unit/equipment under measurement/test.
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So it is not so much trouble comperable to other DSO but in case of Owon only bigger warning ?
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Hello,
Does anyine know where I can find the firmware downloads for the SDS6062? I am hoping to fix the zoom issue with 1M and 10M acquire lengths. My scope has version 2.3.
Thanks,
Sam
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So it is not so much trouble comperable to other DSO but in case of Owon only bigger warning ?
There is no difference between the Owon and other DSOs in this respect. In fact, the Owon, if battery powered, can be used to measure low voltages with references other than ground as long as the difference between ground and the reference is not a dangerous voltage.
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Hello,
Does anyine know where I can find the firmware downloads for the SDS6062? I am hoping to fix the zoom issue with 1M and 10M acquire lengths. My scope has version 2.3.
Thanks,
Sam
Try http://www.owon.com.hk/main.asp (http://www.owon.com.hk/main.asp)
just make sure you don't enter the last three digits of your serial.
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Happy New Year to all.
The link that TomC gave you (http://www.owon.com.hk/main.asp (http://www.owon.com.hk/main.asp)) works and with the main characters of model, e.g only the "SDS6062" vs "SDS6102XXXX" and the result will be : all the available fw's for this scope.
By the way, where is the new fw that Owon promised us?
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Well it still seems to be missing. I think that right now, they're probably too focused on their TDS series to care much about SDS.
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Who's gonna buy the TDS series?? It is too expensive for hobbyists... But not good for professionals...
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Who's gonna buy the TDS series?? It is too expensive for hobbyists... But not good for professionals...
If the voice prompts are poorly implemented and I get a review unit... It might go flying out the window before I do anything
"Nothing to trigger. Nothing to trigger."
*mutes warning*
"No probes. No probes"
*flying oscilloscopes redefined*
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So, I have received my scope. How can I check the firmware version? I want to watch signals from SMT ICs (TQFP, SOIC). I found probe adapter on ebay
http://www.ebay.com/itm/2-Tektronics-Probe-206-0364-01-SMT-KlipChip-Adapter-for-025-Pin-Receptacles-/231044105881 (http://www.ebay.com/itm/2-Tektronics-Probe-206-0364-01-SMT-KlipChip-Adapter-for-025-Pin-Receptacles-/231044105881)
Will it work?
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Those are certainly fine test hooks but they're discontinued and they're kind of expensive.
The oem part for the Tektronix part is here:
http://www.testpath.com/Items/SMT-IC-Test-KlipChip-Adapter-Each-123-642.htm (http://www.testpath.com/Items/SMT-IC-Test-KlipChip-Adapter-Each-123-642.htm) and is a little bit cheaper.
You should look for the EZ Hook xkm that they're very popular:
http://catalog.e-z-hook.com/item/test-hooks/e-z-micro-hooks-single-hook-style/xkm-1? (http://catalog.e-z-hook.com/item/test-hooks/e-z-micro-hooks-single-hook-style/xkm-1?)
The cost less than $3.50 a piece depending where you get them from and the quantity.
I have both and I like both, they grab the pins very firmly but they're delicate as all the probes of this size.
There is a good page with a review of the different types of hooks:
http://sigrok.org/wiki/Probe_comparison (http://sigrok.org/wiki/Probe_comparison)
I hope this helps :)
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So, I have received my scope. How can I check the firmware version?
Press: Utility, Function, Config, About
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Hello Group,
Well I have an update. The SDS6062 that I bought for my company that had the strange operation (corrupted data) when zooming in on captured waveforms has been fixed.
I contacted the vendor where I bought the scope (Saelig) and their service department got right on the problem which I suspected could be fixed with a firmware update.
Well it turned out that the main board was a very early one that could not be updated in the field so Owon supplied a new board which Saelig promptly swapped out and quickly returned the scope to me.
I would highly recommend Saelig to anyone considering the acquisition of test equipment for brands that they carry. Their service and support is excellent!
Now back points about the scopes.
There is one thing to note with this long memory scope that is also common to the SDS7102. If you use the single shot mode and zoom after the scope stops (using the main sweep, not the window mode) you can zoom in on the waveform and the scope waveform fidelity is very good. I have compared this to a deep memory LeCroy scope set to exactly the same parameters (acquire memory set to 10Mpts with the sample rate set to match the Owon) and the results are for all practical purposes is excellent.
However the Owon does not come even close to the math, cursor control and zoom ability of the LeCroy (WaveRunner and more advanced versions) but here again we are comparing the Owon to a scope that costs 50 to 60 times as much.
There is another issue one should be aware of. If you do the same test and put the scope into Normal trigger mode as opposed to Single Shot trigger mode and you zoom in using the time base control after the scope triggers, the stored waveform looks like a sparse number of points are captured. I ran this same test on the Rigol DS1102E and found the exact same issue. I believe that this may be due to the way that the scope rearms after a trigger, a matter of a lack of horsepower in the machine. When you zoom in this mode you will also find that the indicated sample rate changes as you zoom in, which is strange since the scope is actually stopped but waiting for the next trigger. I appears that the sample rate follows the rate the scope would display if it is set to the Auto mode of triggering.
It would really be great of the scope would work the way it does when using the single shot mode with the long memory in Normal mode.
Many times you are looking for a needle in a haystack and having long memory makes the job easier. Sometimes using the single shot mode is impractical when you are looking for an anomaly that might occur when the scope is blind when you are manually setting the single shot each time. Normal mode would help to reduce the likelihood of this problem.
Unfortunately all of the Chinese scopes that I have come across thus far with long memory have been seriously lacking in the memory management department. But for under 400 buck on sale what do you want!
One more annoyance. When you are in Single Shot mode if you move the trigger level control the trigger does not move or change. You have to run the scope in another mode to set the level first then switch to Single Shot mode. I think that is a bug they can fix.
Sam
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Hi! I think that you're wrong concerning the single-shot and normal mode (or at least you would be if you were using SDS7102).
Try this: Connect a probe to the probe compensation terminal, set the scope to 10 ms/div and do a single-shot. Then zoom in to 20 ns/div. You should be able to see the scope switch from interpolated view to dots mode. I'm pretty sure that at this moment, the interpolation loses any significant meaning, since there's so little data points to work with.
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There is another issue one should be aware of. If you do the same test and put the scope into Normal trigger mode as opposed to Single Shot trigger mode and you zoom in using the time base control after the scope triggers, the stored waveform looks like a sparse number of points are captured. I ran this same test on the Rigol DS1102E and found the exact same issue. I believe that this may be due to the way that the scope rearms after a trigger, a matter of a lack of horsepower in the machine. When you zoom in this mode you will also find that the indicated sample rate changes as you zoom in, which is strange since the scope is actually stopped but waiting for the next trigger. I appears that the sample rate follows the rate the scope would display if it is set to the Auto mode of triggering.
It would really be great of the scope would work the way it does when using the single shot mode with the long memory in Normal mode.
Many times you are looking for a needle in a haystack and having long memory makes the job easier. Sometimes using the single shot mode is impractical when you are looking for an anomaly that might occur when the scope is blind when you are manually setting the single shot each time. Normal mode would help to reduce the likelihood of this problem.
Unfortunately all of the Chinese scopes that I have come across thus far with long memory have been seriously lacking in the memory management department. But for under 400 buck on sale what do you want!
One more annoyance. When you are in Single Shot mode if you move the trigger level control the trigger does not move or change. You have to run the scope in another mode to set the level first then switch to Single Shot mode. I think that is a bug they can fix.
Sam
Scopeman,
I can confirm that my SDS7102 has the same behavior you described as far as the difference of the number of points displayed when zooming in single shot trigger mode versus normal trigger mode. One point of caution for others trying to reproduce this behavior, the sparse number of points in normal mode only happens if the scope triggers and then stops in the ready state waiting for the next trigger. It doesn't happen if you stop the scope manually with the stop button.
As far as the trigger level not working when in single shot mode, I couldn't reproduce this behavior on my unit. It seems to work as expected and for example, I can lower the trigger level from a point above the signal level to a point within the signal level and cause a single trigger to occur. Perhaps there is a difference in the firmware in this respect or our firmware levels are different.
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New PC Software from Owon 2.0.8.21 without history changes.
I can't see what they changed.
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I didn't read the whole thread so someone may have brought this up but as far as I can tell SDS series are all Siglent ifound this when with a great deal of trouble I got onto SIGLENT and they sent me upgraded firmware Owen to SIGLENT and then I asked for help with a DIGITECH Scope QC1932 this is now a Siglent scope that is able to use EASYSCOPE X this allows SPI code to be used to control the scope Like UltraSigma for RIGOL except it is a Screen display with the SPI being usable to change scope settings etc. As a side piece the instructions are a lot clearer and easier to use than RIGOLS version. Oh! and it uses NI's drivers also.
Hope this Helps
Rachael :-+
PS I think MARMAD wrote RUU which is fantastic if I have used the wrong name I am sorry but that program is really great.
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I can't understand well.
Are used a Siglent fw to SDS Owon?
Can you used the EasyScope X with the Owon?
Could you be more specific?
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I didn't read the whole thread so someone may have brought this up but as far as I can tell SDS series are all Siglent ifound this when with a great deal of trouble I got onto SIGLENT and they sent me upgraded firmware Owen to SIGLENT and then I asked for help with a DIGITECH Scope QC1932 this is now a Siglent scope that is able to use EASYSCOPE X this allows SPI code to be used to control the scope Like UltraSigma for RIGOL except it is a Screen display with the SPI being usable to change scope settings etc. As a side piece the instructions are a lot clearer and easier to use than RIGOLS version. Oh! and it uses NI's drivers also.
Hope this Helps
Rachael :-+
PS I think MARMAD wrote RUU which is fantastic if I have used the wrong name I am sorry but that program is really great.
I'm sorry, but what?? Can you please ty using proper punctuation and capitalization? I really can't figure out what's going on here. I think that you're implying that Owon scopes are somehow related to Siglent. If that's so, then please elaborate. I don't think that anyone presented any proofs about the connection before.
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BIG CAUTION! Owon technical support is absolutely worthless. The PC software package available on their site does not support Windows 8, there is a forum comment suggesting a new version is available but the support people simply sent a generic Windows Driver Config document that has nothing to do with the problem. When asked a second time there was no reply. I'd suggest buying a different product from a company that can read and respond to simple emails.
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:-( :-( :-( :-(
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BIG CAUTION! Owon technical support is absolutely worthless. The PC software package available on their site does not support Windows 8, there is a forum comment suggesting a new version is available but the support people simply sent a generic Windows Driver Config document that has nothing to do with the problem. When asked a second time there was no reply. I'd suggest buying a different product from a company that can read and respond to simple emails.
Can you describe the problem that you are having and post a link to the forum comment? I've been using the PC software with Windows 7 64bit for some time, and although clunky, it mostly does what is supposed to do. According to Microsoft, almost all programs that work with Windows 7 should work with Windows 8.
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Hello Everyone! Just bought a Owon SDS7102V from SMTZONE and got it a week ago (20th Feb 2014), Serial Number SDS7102- 1352526. Very excited - my first scope!
*I Got Average 60-80mv Vp of Noise: After testing it as per TomC's post (https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/1066/ (https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/1066/) which in essence was to clip both the ground and the probe to the GND clip on the "Probe Comp tongs" [those who have one will understand what I mean], done after: [calibrating the unit, doing the probe compensation, setting probe at X10, and reading from the 50mv setting on AC coupling and Limit Full Band]) -- Image of signal as attached; I did it many times in many other rooms, and on *** average stayed 60-80mv Vp (volt peak to peak) of noise** . The results is the same whether I do it on CH1 or CH2.
** Question: Is TomC's test still valid, is there a test that supercedes this test? In theory I waited long enough after Jun 2013, and my unit should not have the noise problem, right? I am waiting for Owon support to confirm that my unit is not the older unit in the first place.
Thank you very much in advance!
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Hello Everyone! Just bought a Owon SDS7102V from SMTZONE and got it a week ago (20th Feb 2014), Serial Number SDS7102- 1352526. Very excited - my first scope!
*I Got Average 60-80mv Vp of Noise: After testing it as per TomC's post (https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/1066/ (https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/1066/) which in essence was to clip both the ground and the probe to the GND clip on the "Probe Comp tongs" [those who have one will understand what I mean], done after: [calibrating the unit, doing the probe compensation, setting probe at X10, and reading from the 50mv setting on AC coupling and Limit Full Band]) -- Image of signal as attached; I did it many times in many other rooms, and on *** average stayed 60-80mv Vp (volt peak to peak) of noise** . The results is the same whether I do it on CH1 or CH2.
** Question: Is TomC's test still valid, is there a test that supercedes this test? In theory I waited long enough after Jun 2013, and my unit should not have the noise problem, right? I am waiting for Owon support to confirm that my unit is not the older unit in the first place.
Thank you very much in advance!
Yes, the test is valid. It appears that you have done the test correctly and you have more noise than I would expect for a unit at your serial number level. I wonder what boards are inside of your scope, there was a case some time ago where the boards inside a scope didn't match what would be expected given the serial number. I don't know if you want to risk opening the scope or just try to exchange it.
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Thanks very much for the fast reply TomC! [ If you/Marmads come around Bangkok, Thailand, feel free to call me for local support -- free lunch! :> ]
What would be the current Low-Noise mV peak to peak (Vp) that others are getting or that I should be getting? How far should I be away from other power adapters/transformers (most are 220v AC to 12v DC) so that the noise does not effect my Oscilloscope?
When I saw the noise I was getting I was alittle frustrated -- I tried measuring 12V battery's as well as 1.2V battery's [AC Coupling mode] and I see quite the same noise, albeit slightly less Vp maybe 50-60 mVs. So I suspect that I may have something internal that is differnt to the serial number, and now SMTZONE and Owon is helping to investigate.
Thanks again,
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Thanks very much for the fast reply TomC! [ If you/Marmads come around Bangkok, Thailand, feel free to call me for local support -- free lunch! :> ]
What would be the current Low-Noise mV peak to peak (Vp) that others are getting or that I should be getting? How far should I be away from other power adapters/transformers (most are 220v AC to 12v DC) so that the noise does not effect my Oscilloscope?
When I saw the noise I was getting I was alittle frustrated -- I tried measuring 12V battery's as well as 1.2V battery's [AC Coupling mode] and I see quite the same noise, albeit slightly less Vp maybe 50-60 mVs. So I suspect that I may have something internal that is differnt to the serial number, and now SMTZONE and Owon is helping to investigate.
Thanks again,
From what I've seen most get under 40mVs. The most troublesome power adapters are the ones that use SMPS like the ones for laptops. You can see a change in noise level as you get one of these close to the probe cable. To help rule out outside interference you can use ferrite cores on the probe cable, one at each end with the cable looped once if possible for extra inductance. Also keep the probes away from the scope's screen, as that produces a lot of radiation. I always keep ferrites on my probe cables so I don't have to worry that much about outside interference. I don't think that the noise level you are seeing is outrageous, but I would have expected a little less with a newer scope. Let us know what you find out! Good luck! :)
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Hi to all members...
As TomC said, your noise level isn't bad, but we would have expected a little less with a newer scope.
Ours scopes are older than yours and most of us, we have adapted the psu and adapter boards or change them with the new ones. You see my results with the new psu & adapter board at #2242 post.
I have a concern, if your scope probe cable was at fixed place or free on the table.
Kuson, please repeat the test like the attachment photo of #1330 post and give us the result.
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I found EDS102C/V on taobao:
http://item.taobao.com/item.htm?spm=a230r.1.14.23.1mbuPl&id=13859092514 (http://item.taobao.com/item.htm?spm=a230r.1.14.23.1mbuPl&id=13859092514)
It's seems to be the same as SDS7102V. Am I right?
Damn, I finally found the post where the guy managed to enable the language packs.
http://radiokot.ru/forum/viewtopic.php?p=1725552#p1725552 (http://radiokot.ru/forum/viewtopic.php?p=1725552#p1725552)
Now, does anyone speak russian? |O
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[RE-POST WITH PICTURES]
Hi Lemon, TomC,
Thanks for your posts! Here is the results after coiling the cord as per your recommendations.
For CH1, the noise came down lower to ~60mv Vpp...... this same noise level also gets registered when I measure normal 1.2v or 6v DC batteries; I went to do this at my garage, far away from any nearest wall-wart. For CH2, I'm getting around 10mV.
I'm concerned about CH1 -- Does my oscilloscope be considered ok? I've seen your posts with the modded components and it looks like the 10mVs, which is far better than what I'm getting. I've emailed to SMTZONE and them to OWON and the quick and short reply is my oscilloscope is ok (which I'm not sure); I've asked them what tests I can conduct further and there is NO REPLY whatsoever :(
Thank you so much again, TomC ,Lemon,
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[RE-POST WITH PICTURES]
Hi Lemon, TomC,
Thanks for your posts! Here is the results after coiling the cord as per your recommendations.
For CH1, the noise came down lower to ~60mv Vpp...... this same noise level also gets registered when I measure normal 1.2v or 6v DC batteries; I went to do this at my garage, far away from any nearest wall-wart. For CH2, I'm getting around 10mV.
I'm concerned about CH1 -- Does my oscilloscope be considered ok? I've seen your posts with the modded components and it looks like the 10mVs, which is far better than what I'm getting. I've emailed to SMTZONE and them to OWON and the quick and short reply is my oscilloscope is ok (which I'm not sure); I've asked them what tests I can conduct further and there is NO REPLY whatsoever :(
Thank you so much again, TomC ,Lemon,
It seems that you have Ch2 set to 10mV/div for the Ch2 test. That cuts down the bandwidth and makes the noise appear to be less. What do you get with Ch2 set to 50mV/div?
Edit:
After looking at your Ch2 photo magnified I think you have the scope's probe setting for ch2 set to X1. But since the probe itself is set to X10, you have to multiply the reading by 10. What you think is 10mVs is really 100mVs. As far as whether your scope is OK or not, I think it probably falls into the category of normal, but still a little noisier than average. To help rule out external noise, have you tried ferrites on the probes? I attached a photo so you can see what I mean.
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Please, follow exactly the procedure. Keep the same schema of probe cable as you tested the last one.
For this reason, I quote the post #1330.
Very well!
The noise is low without any peaks.
The member "rf-loop" had suggested a method for this.
Procedure for measurent of Noise GND
----------------------------------------------------
Make a Calibration procedure as the notes says (look in manual).
Compensate the probe as manual described.
Change switch probe to 10x.
Do the same and the Probe Owon Menu (10X).
Connect probe to Probe Comp and GND wire to GND. Fix the cable of probe like the attachment photo.
Turn CH2 off.
CH1 to DC, 50mV/Div.
Push Trigger 50%
Set the Acquire Length to 1M and the Mode to Peak
Set the Horizontal speed to 100us
Set the measurement to Voltage peak to peak (Vp to Owon) and write the value.
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TomC Lemon!
I have ordered the ferrite cores from Ebay :)
I have got the noise down abit to about 40mV Vp for both channels 1 and 2-- perhaps it was about the winding of the cables and quite hopeful the ferrites would help :)
Will update when I get them in 2 weeks :) Thanks so much for your feedbacks-- really appreciate them :)
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TomC Lemon!
I have ordered the ferrite cores from Ebay :)
I have got the noise down abit to about 40mV Vp for both channels 1 and 2-- perhaps it was about the winding of the cables and quite hopeful the ferrites would help :)
Will update when I get them in 2 weeks :) Thanks so much for your feedbacks-- really appreciate them :)
That looks good! :-+
What you see now is in the average range. This amount of noise shouldn't impair readings of low level signals when you use full bandwidth, which is the major objection to excessive ground noise.
The ferrites will help keep common mode noise at bay, which will result in a more consistent experience in different environments. Without the ferrites, the probe cables will pick up more common mode noise from the environment, e.g. wall warts, other electronic equipment, radio/TV stations, fluorescent lights, etc., and because you are using a long ground wire, the common mode noise is changed into differential mode noise which you then see on the scope's screen.
For cases where you want to see the best possible representation of the true signal it is best to use the shortest ground lead you can possibly get away with, or better yet, use a probe test point. This will prevent the common mode noise from being changed into differential mode noise. Although the common mode noise will still be present, it will be invisible to the scope's input amps and therefore you won't see it on the screen.
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Kuson, you are OK. :-+
...For cases where you want to see the best possible representation of the true signal it is best to use the shortest ground lead you can possibly get away with, or better yet, use a probe test point. This will prevent the common mode noise from being changed into differential mode noise. Although the common mode noise will still be present, it will be invisible to the scope's input amps and therefore you won't see it on the screen...
I took the spiral of this rca
(http://www.teamluco.co.za/image/cache/data/products/connectors/rca-plug-gold-red2-600x500.jpg)
and done some short ground clips like this (in various sizes) :
(http://t3.gstatic.com/images?q=tbn:ANd9GcRl0za0NrQ_0q91vETjqcS9r7X0zwQtwqbkSV--2_Wq19jMyRtO7g)
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Great idea! :-+
Thanks for the pics.
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TomC Lemon!
I have ordered the ferrite cores from Ebay :)
I have got the noise down abit to about 40mV Vp for both channels 1 and 2-- perhaps it was about the winding of the cables and quite hopeful the ferrites would help :)
Will update when I get them in 2 weeks :) Thanks so much for your feedbacks-- really appreciate them :)
Plz can u tell us which ferrite you have orderded? Eaby link would be nice.
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RmanNL,
I bought http://pages.ebay.com/link/?nav=item.view&id=360479080355 (http://pages.ebay.com/link/?nav=item.view&id=360479080355) it was larger than the probe cables but fit the tapered ends of the cables. Not sure if these were supposed to fit snug on the cables themselves!
Sorry Lemo TomC I tried to upload pictures from my mobile device but thw pix was over 2MB... I got 34-38mV Vp as a result of putting 2 ferrous cores on each side ... the probe side and the plug side-- will upload to you later but many thanks and tell me when you come to TH :)
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RmanNL,
I bought http://pages.ebay.com/link/?nav=item.view&id=360479080355 (http://pages.ebay.com/link/?nav=item.view&id=360479080355) it was larger than the probe cables but fit the tapered ends of the cables. Not sure if these were supposed to fit snug on the cables themselves!
Sorry Lemo TomC I tried to upload pictures from my mobile device but thw pix was over 2MB... I got 34-38mV Vp as a result of putting 2 ferrous cores on each side ... the probe side and the plug side-- will upload to you later but many thanks and tell me when you come to TH :)
Very good results! :-+
I see you got 7mm ferrites, the ones I'm currently using are 8mm. They don't need to be snug on the cable. However, what I recommend, which I'm not sure if you are doing yet, is to loop the cable once around the ferrite on each end. This way the cable goes twice through the ferrite on each end and you get twice the inductance. If you haven't done this yet, give it a try and see if there is any improvement.
Good luck! :)
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Dear TomC,
From Original Thread: Owon SDS7102 (page 158) Ground Noise on Owons purchased on Jan 2014 (New Manufacturing Batch) --> RESOLVED THANKS TO TOMC, LEMON
Here are the pictures at last! I tried the loop at the Ferrous Cores on each side of the ProbeCable (as pictured, not sure if I did it right ) and now I have the noise to 14-15mV Vpeak!
Thanks Again TomC, Lemon :> Now I can bravely face all the New Stuff to learn with the help of the Oscilloscope!
What are good stuff to poke around with this oscilloscope to learn the different kinds of readings? (Low Priority Question) :>
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Looks good! :-+
Don't be discouraged, but your real noise reading is probably a little higher than you think. I noticed that you are using 20mV/div. This restricts the bandwidth and as a result some of the higher frequency noise is filtered before it reaches the screen. To get your true noise level you need to use 50mV/div.
Best of luck! :)
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The test: It is 46 mV Vpp.
update: Exactly after 21:00 its
12 -14 mV Vpp --- acquire peakdetect
8 mV Vpp ---acquire Average 4
Owon: DS7102V
serieno: SDS71021407522
version: 3.5
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The test: It is 46 mV Vpp.
update: Exactly after 21:00 its
12 -14 mV Vpp --- acquire peakdetect
8 mV Vpp ---acquire Average 4
Owon: DS7102V
serieno: SDS71021407522
version: 3.5
What I see on the screen looks very good! :-+
About 25mVpp on average except for the larger pulse in the center of the screen.
I'm not sure what you mean by "Exactly after 21:00". But from what I can see you have the kind of normal results we expect from newer scopes!
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The test: It is 46 mV Vpp.
update: Exactly after 21:00 its
12 -14 mV Vpp --- acquire peakdetect
8 mV Vpp ---acquire Average 4
Owon: DS7102V
serieno: SDS71021407522
version: 3.5
What I see on the screen looks very good! :-+
About 25mVpp on average except for the larger pulse in the center of the screen.
I'm not sure what you mean by "Exactly after 21:00". But from what I can see you have the kind of normal results we expect from newer scopes!
9 o'clock am
its now 7:00 pm
and the Vpp = 18- 28 mV Vpp acquire peak detect
8.000mV Vpp acquire Average
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If the noise changes like clockwork at certain times, I doubt that it's something in the scope that's causing that. I would suspect external interference of some sort. Perhaps someone in the neighborhood turning on a transmitter, generator, or other type of equipment that generates RF. Have you tried ferrites on the probe cables to see if the effect is less. In any case, I think that the amount of noise that you are experiencing is very small and shouldn't interfere when viewing low level signals. Let us know if you find the source!
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The test: It is 46 mV Vpp.
update: Exactly after 21:00 its
12 -14 mV Vpp --- acquire peakdetect
8 mV Vpp ---acquire Average 4
Owon: DS7102V
serieno: SDS71021407522
version: 3.5
Very good results!
I see a new firmware 3.5!
At Owon's site the fw is 3.3 still!
My opinion for that oscilloscope is remaining the same. Good hardware, average software. Unfortunately, the chinese Owon doesn't developed the software. Many of us, send to them some suggestions for the fw but Owon was deaf!
I see at your fw (3.5) that the Vpp appears Vp still!! :palm:
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Hi everybody,
finally I found you after some time searching the web for OWON users.
I bought a SDS 9302 a while ago and when testing it soon dicovered the noise problem.
At first couldn't believe it and wrote to OWON but they did not answer.
After opening the thing and further testing soon I located the problem. It's as you also know - I haven't yet read through the entire post here so forgive me if I repeat things already posted - the power supply, the main one but also the distributed little switchers as i found out later.
I couldn't stop my self and started to denoise the main PS. After that lots of spikes where still present and I contacted the seller of my OWON (Präzitronik Hennig / Messgeräte Chemnitz) and he send my mail again to OWON and this time they answered that they are already working on the problem and also send the service manual I had asked for.
So, meanwhile I was digging myself deeper and deeper into this Scope and finally realized what they did. IT'S UNBELIEVABLE!!!
I think I have to say now that I worked with Tektronix for about 10 years as a service engineer her in Germany. Now I'm retired since many years but still do electronics a lot .
Yeah, back to the OWON, Step by Step I removed the little Buck converters from the interface PCB and even one from the main board - AGAIN UNBELIEVABlE TO PUT AN UNSHIELDED HIGH FREQUENCY SWITCHER ON THE SAME PCB WHERE THE INPUT CIRCUIT IS!
Next thing was to give the input circuit a decent shielding soldered tight around the input circuit on the main PCB and with the covers screwed on for to have access still.
I'm not through with all the switchers yet. One is still left thats the one for the Display, not the backlight. I couldn't find any IC datasheet for this one and also the one that provides the power to the LED backlight. Perhaps one of you found that out and can post it here maybe again for me until I heve read through all pages.
Will also check the display maker, Maybe there is some app note with these switchers.
I have the schemes of what I did so far, could reduce the noise remarkably, and if you are interested can also post some photos of what I have done.
For the moment I will stop and wait for what you say.
Thanks for reading + best wishes.
Sarasir
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Very interested in what you have done so far, by all means, post photos and schematics! :-+
I own an SDS7102 and have replaced the main PS board and use some ferrites internally and on the probes to reduce noise. Now in the less than 30mVpp range. :)
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here my first steps:
you can see the tin box I made for the main SMPS and some filtering. Also on the back side of the PCB I cut the second heat sink free and connected it to output ground so it serves as a shield as well (ONLY POSSIBLE IF A FULLY ISOLATED SCHOTTKY RECTIFIER IS USED!!!!! In my model it was so).
At that stage I still was so naive to believe that by doing this mod the problem would be solved!
Therfore I also replaced the knobs as you can see. Pardon me, but the original ones are just a pain in the ass.
But that ment also that I couldn't go back and return the thing because to take the original ones off without somehow damaging the 'potentiometers' - they where absolutely tight - I decided to cut them off carefully.
I also had to turn around the mains input mudule to give more place to the tin box.
This Mod reduced the noise a bit but there was still too much....
And be aware, that I'm not through yet with the little converters so no final results now to tell only that the noise got lesser and lesser with each step I made.
To be continued ....
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sorry, by getting all together and taking and posting the pics I forgot to reply to you:
Yes, 30mV, better than nothing of course but what means that for a scope at 2mV or 5mV input/division sensitivity as on mine - probably yours as well? It means, in my view that you can not use it when you have to check e.g. a phono pramp and what else low level circuit... And these spikes also make triggering practically impossible at low levels.
I can not live with that. A scope must be clean otherwise you never know is it the scope or your DUT.
Also had the idea to replace the main SMPS even with a conventional transformer design but only untill I discovered all the liittle converters.
I think the final solution will be to take all little switchers off from the PCBs and put them in one tight tin box.
But well see - And somhow I really love this little bastard. Aside from above probs it's designed really nicely and cute.
Men need challenge I would say...
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Hi Sarasir,
Very interesting changes. Thanks for the pictures! :-+
On the SDS7102 the noise is much more bothersome when using the X10 probe setting with the long ground lead at the 50mV/div setting. Those are the test conditions for the <30mVpp noise figure I quoted before. At 20mV/div, which is the lowest possible setting in this case, the noise is less because the bandwidth is limited to 20MHz. Also, if the X1 probe setting is used the noise is much less because the probe then limits the bandwidth to about 6MHz.
I noticed from your pictures that your unit uses the previous version of the PSU, T115-N Rev3. This is the PSU that was also originally installed in my unit. While I was trying to modify it I made a complete schematic of this particular version, I attached a copy in case this may be useful to you. My final modifications consisted of adding a belly strap to TR1 and replacing L2 with a hand wound toroid. I'm still using this PSU in my unit, the noise level with these mods and a ferrite on the ribbon cable are as good or better than what I get with the new style PSU.
I also attached images of the new style PSU. On the printed circuit side you can see a number of SMD capacitors that were added by Owon to reduce noise. They also isolated the Power Switch's casing from GND-C to prevent it from radiating noise. In addition, they changed the connection of D8's heat sink just as you did on your unit. So it is no longer connected to the anodes of D8 and instead is connected to GND-C. Other than these changes, the schematic I made is the same for this newer PSU version.
Again, I would like to see more of what you are doing, and let me know if there is anything I can do to help! :)
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Hi TomC,
thanks God finaly sombody to talk to who knows what I'm speaking about. :-+
And thanks for the Scheme/pics. I will check them later 'cause just got up. Wow!
Of course I will post everything I did with all notes/schemes/photos. Just all scribbled on loose paper and needs to be checked again before posting. And these was the first pics I made. You know when I'm working I do not spent so much time on documentation but I know I schould - but everything's here...
Until later - now I'm on skedule....
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For such an expensive 1500 Dollars scope I would expect a better internal construction. :-- :--
http://www.testequipmentdepot.com/owon/sds-series/sds9302.htm (http://www.testequipmentdepot.com/owon/sds-series/sds9302.htm)
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yes of course I see what you mean Hydrawerk. It's quite some money and as I already said I couldn't believe it. And if you look at the necessary mods that I believe will do, it's just cents: Some tin boxes, inductors with tantalums or equivalent and an extra little PCB for all the switchers and in turn the interface PCB then can be made smaller. On the Chinese market almost nothing I guess. And therefore they are ruining their name and reputation. And everything else is nicely done. The guys of OWON should study their own culture 'cause there is a chinese saying: Missing it by a little can lead you very far astray.
But you know, I'm learning new things and there is also a lot of fun and if we made it we feel like kings. What else can you ask for in life? Money? And I tell you I made quite some money in my life with electronics through what I've learned from all my crazy projects, really.... no school makes you learn better and you will never forget it anymore.
TomC,
have everything together but will post it tomorrow. I'm tired now and it's late.
For now I will attach two pdfs that helped me a lot to develope understanding of what goes on in these OWONS. Didn't torture myself with the formulas just the text works out everything clearly...
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This SDS 9302 is for some specific needs when you need 300MHz bandwidth and nothing else, but for a hobbyist 100MHz might be enough.
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Hi Sarasir,
Those are two very interesting papers! :-+
I also have an extensive collection of PDFs that deal with SMPS design, noise reduction, etc. So I will add these new papers to my collection, thank you!
There is also a paper on the theory of operation of the T115-N Rev 3 PSU that I started writing before trying to modify my PSU for lower noise, see attachment. I didn't finish it so it is not complete but it may be helpful if you haven't figured out yet what some of the components are supposed to do. Note that the information in red were notes to myself for things to check and try out, later I found out that most of this didn't require any action, but I never updated the document. Also I never updated the information on the snubbers, although later on I found out that Owon used R2CD snubbers that rely on the operation of slow recovery diodes like the 1N4007. Anyway, hope you can get something out of it.
By the way, I agree with you that trying to improve these scopes is a great learning experience. In my case, it made me investigate deeply into the operation of SMPS, which I only understood superficially before. I also think that a 300MHz scope, even just for hobby use, can provide you with useful details that otherwise would be invisible. And that alone justifies the cost to me if you can afford it. I would have gotten a 9302 also, unfortunately, justifying the cost to my wife wasn't quite that easy.
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As Mark Model video shows (23:30-24:10)we can see the output (using the vga ) of scope on a desktop screen in a Window (or Ubuntu?) environment. What hardware and/or software do I need?
I'm using now Ubuntu 14.04/Windows 7 with a hdmi cable connection to my 24 inch screen.
https://www.youtube.com/watch?v=eqcEi6ru4ZM (https://www.youtube.com/watch?v=eqcEi6ru4ZM)
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As Mark Model video shows (23:30-24:10)we can see the output (using the vga ) of scope on a desktop screen in a Window (or Ubuntu?) environment. What hardware and/or software do I need?
I'm using now Ubuntu 14.04/Windows 7 with a hdmi cable connection to my 24 inch screen.
https://www.youtube.com/watch?v=eqcEi6ru4ZM (https://www.youtube.com/watch?v=eqcEi6ru4ZM)
There is direct VGA output on the SDS7102V. (native resolution 800x600 and pixel to pixel realtime copy from Owon own TFT display))
Direct VGA cable to monitor, (or VGA to what ever adapter) thats it and also it is only way to get realtime parallel display.
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Hi TomC,
I just read through your Theory Of Operation paper and schematic for the OWON SMPS and was quite impressed. Increased my understanding of whats going on inside these things significantly.
And, by the way, found the data sheet for the MOSFET and will attach it.
First about the residual noise and your noise figures.
In general I have to say that when testing/calibrating scopes you never use probes. The scope must perform the same whatever you connect to the input. So, stating any results by feeding the scope via a probe puts two things in one pot and nobody can tell which component is responsiuble for what and how much.
The only step in a calibration procedure of a scope where you need something like a probe is the input capacitane adjustment and this - at least in Tek labs - is done with a so called NORMALIZER a simulated 'perfect' probe with a known and calibrated capacitance matching the specified input capacitanc of the scope. And you adjust the input capacitance of the scope then for a flat square wave like you would do later with a probe that in turn will have to be adjusted to match the scope's input capacitance.
As a reply to you noise figures I will describe the noise problem of the OWON now as I experienced it when testing the machine and try to interpret it a bit of course according to my current knowledge (I might be wrong because of having overseen something - but don't think so):
Test setup example: Connect the output of whatever device to be maintenanced or tested to CH I input and a probe to CH II input.
Then shorten the tip of the probe with the groundstrap of the probe. How much noise do you see on screen provided the shorted tip end of the probe is as far away from the scope as possible?
Answer: nothing or almost nothing (no noise). Then take the ground strap off from the tip and touch the scopes input connector which is supposed to be solid ground. And what do you see on screen? Answer: Lots of spikes!!!
And now start tipping around inside of the device to be maintenanced/tested.
What will you see?
I can not tell at what level or what phase or spectrum but it will be noise everywhere except if you are lucky and find a point of Zero for all frequencies (not very likely).
I also depends on whether and how the device is grounded by itself, through the mains cord or whatever.
Conclusion is, that the OWON pollutes every conducting thing you connect to it's ground as good as it can. Using long wires and in addition grounding the thing to your central heating radiator the OWON has a very hard job. Is the thing a floating battery operated device and the connection to the OWON very short and done with HF wire it will pollute the thing entirely but you will not be able the see it on screen because the tip of your probe might be in perfect phase with the thing connected to OWON's ground. But after connecting something else with big mass or even grounded to the thing your measurements will show different again.
Its not the hot side only of the input that is pulluted! It's the COLD SIDE AS WELL. And that means actually you can not predict the displayed noise at all.
So I have to say that any noise figure you give can only be true for the individual setup you had.
To the attempts of OWON reducing the noise by circuit mods I can only say that the result can be only marginal. They should know better. Of course as you pointed out in your paper 'slowing down' the slopes would help but there are hard limits as you wrote (Power consumption / component sizes).
How much reduction did you get with the belly strap and hand wound toroid? and what material did you use, chopper foil?
And another thing I would like to ask you: please can you check what is written on the backlight switcher controller and the screen supply switcher controller. I can not fine the sheets in the net and the screen supply is a bit complex as it prvides the power up sequence for the various display voltages. Found the spec sheet of the display with power up sequence detailed but no app circuit given. I will retrace it but you know missing a little and killing the diplay wouldn't be so great. Datasheets are always a good backup also if some resistor breaks when unsoldering or jumps away.
And my postings - all a bit rough and preliminary. The final design of the smal converters I will do after I have everything together.
1. 3.3V buck converter: In the box is what was on the I/F PCB just added Inductors + tantalums as filter
2. 5.6V buck converter: removed all components and replaced it with a linear 7805 + diode for 0.6V increase. maybe will keep it but will decrease battery time should I ever need it. To be decided later.
3. 1.9V Buck converter: to be found on the main PCB. removed all parts using hot air but replaced the controller then with the one that did the 5.6V before. The reason was that the original was supplied by the +5,6V converter and by taking it off the main PCB could feed it directly with the 8.4V also taking away current from the 5.6 now linear regulator.
And for the former 1.9V controller 8.4V would be above or just max specs. As the former 5.6v controller has an enable input I could use this to keep up with the correct power up sequence and also power on/off dependencies. (1.9V only present if 5.6V present) It works fine.
So that's it for now. have removed the backlight switcher but not boxed yet. And will continue working on the display switcher.
Next photos will be the input shielding I did and minor mechanical mods for to make a bit more space between button PCB and main PCB (.6mm) but have to dissasemble the thing again before.
Keeping up the good sprit,
Sarasir
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....and here the MOSFET data sheet (Change the extension to rar and unpack it)....
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@ Sarasir:
Below the shielding metal sheets of the input stage there is a 5V LDO, connected to ~5.54V (i.e Vdo <0.54). And if Owon did not put any filters (F.Bead) in the input of the analog power for the DAC, less to the input of the analog power for the input stage. This LDO is able to reject only some frequencies <1MHz. Similar for the 7905.
Good luck!
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2. 5.6V buck converter: removed all components and replaced it with a linear 7805 + diode for 0.6V increase. maybe will keep it but will decrease battery time should I ever need it. To be decided later.
Humm... Many amps for an 7805, at least 2 Amp.
3. 1.9V Buck converter: to be found on the main PCB. removed all parts using hot air but replaced the controller then with the one that did the 5.6V before. The reason was that the original was supplied by the +5,6V converter and by taking it off the main PCB could feed it directly with the 8.4V also taking away current from the 5.6 now linear regulator.
And for the former 1.9V controller 8.4V would be above or just max specs. As the former 5.6v controller has an enable input I could use this to keep up with the correct power up sequence and also power on/off dependencies. (1.9V only present if 5.6V present) It works fine.
Edit:
Ok, now I understand, you got rid of a few amp.
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Hi Carrington,
thanks a lot! I recognized this 5V regulator when redesigning the input shielding but did not think about it any further as I thought its linear and therefore should give no no problem.
TomC,
here I have attached the remainding pics.
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@ Sarasir:
Could you replace all this with batteries or a linear PSU? Just to see the noise floor.
(https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/?action=dlattach;attach=95334;image)
I suppose that you are using ferrites on all the cables in and out the metal caps.
All these cables can be a big problem.
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first time when I used the 7805 was before I had removed the +1.9 switcher from the main PCB that hangs on the + 5.6V and I tell you it worked without the 7805 getting real hot (I placed it on the main chassis where normally the battery compartment is with a mica and screwed a flat spring to one of the threads to hold it down.
After I had removed the +1.9 switcher and connected it directly to the 8.4 volts the +5.6 line drew about 1Amp and the 7805C - version can do I think 1.5A. Before it was - not sure now, was some time ago - less than 1.5Amps. so maybe they have changed certain ICs to versions with lower consumption in my maschine.
But, as I wrote thats only preliminary. If finally I should use a linear Reg at all I will of course use a LowDrop one with higher amp rating.
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...of course you could, but the efford...
No, my concept to get a definite result is to take all switchers out of the machine and put them in closed tin boxes with enough filtering so that they are just clean. Connect them with long cables to the scope and use enough capacitors on the scope side to eliminate the wires influences (HF wise).
Then to ckeck if there is any noise from the digital circuitry (core ++) going into the analog side, and if then it's getting very comlicated as one has to thinker around on the main PCB digitizer circuit and control and therefor have to retrace the circuit first as a start for to know whats going on at all.
I already recognized that they provided no split ground for digital and analog and I think you can guess what that means....
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LDO: https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/msg312500/#msg312500 (https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/msg312500/#msg312500)
And don't use the internal LCD, is another source of noise, including the connector that joins main the boar with the DC/DC board.
Use only VGA output.
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I already recognized that they provided no split ground for digital and analog and I think you can guess what that means....
This, is not always necessary/mandatory. A "no split ground" may be even better.
Trust me, this thing is a nightmare.
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nothing against what you say - it depends on the way the ground distribution is done.
And of course I noticed already the noise radiated from the display but there is no way to say anything defenitely about that as long as these many connecting lines between Main PCB and display all running along on the I/F PCB in close vacinity under 4 of these little switchers. This I/F PCB acts as a perfect coupling device to make sure that all spikes are properly distributed over the entire machine.
Another thing that must have been designed/decided by a dev engineer who rather should be kept away in an assylum for mental cases.
You see the display itself works at a relatively low voltage level signalwise, haven't checked that yet - perhaps around 3V whereas the switchers work from 8.4V and some amps are flowing.
So what would you guess makes more noise, a bunch of low current / low voltage signals or high current square waves at up to 8.4V.
The other thing is that the ground side of the switchers on the I/F PCB are all connected with several screws the the chassis and, very important BEFORE THEY ARE PROPERLY SHIELDED AND FILTERED. If you want to do that right simply remove shield and filter them first and then you connect them to that point in the whole circuitry where most of the amps are needed and nowhere else. This way you create a predictable environment. And the signal display lines running along the I/F PCB after all switchers have been removed can be even wrapped around with some thin metal foil should they also radiate significant noise. And should the radiation going out from the front of the dislay be too much for you you get yourelf one of this conducting but transparent microfabrics that Tek offered as an option for all of its scopes for environments that are highly sensitive to noise radiation. You know, a normal CRT radiates as well out of the screen a little...
I think we can handle all of this. And after we have designed a small pcb for all the little switcher beasts and put them inside of a small tin box that will be screwed through isolated posts above the I/F PCB with no noise going outside of this box and the outputs connected with if you want shielded cables to where the voltages should really go I'm sure we have that thing cured.
And, I tell you if this spreads around the price for this machines will fall and whoever feels like may offer a kit with all inside what we did (will not be me for sure will be off to new shores then) to convert this bastard to a decent device.
Just search ebay for this owons as I did recently. Countless offers came up. Piles of this machines must be out waiting for uninformed buyers. Do you know what I means....?
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Hi Sarasir,
I'm amazed at the number of mods you have made, have you devised a way of quantifying the improvement after each mod? Personally, I'm always curious about the effort/improvement ratio. Not that it matters much if the goal is near perfection, and it seems to me that you are well on your way toward achieving that! :-+
As far as the noise tests, I'll try to explain what we have been doing so far and why. It all starts with the symptoms of what we've been calling GND noise in the SDS7102s. On scopes that are not otherwise defective, it manifests itself when the probe, set to X10, is used in combination with the 6" ground lead, or strap as you call it. On these scope the base line noise is negligible, about 1mV, and signals, including low level ones, are virtually noise free when the spring ground clip is used instead of the 6" ground lead. However, when the 6" ground lead is used there is HF noise with spikes riding on the signal, this noise persists even if both the probe tip and the 6" ground lead are connected to the scope's ground lug. The amount of noise varied quite a bit from unit to unit, in my case, it was in the range of 100-150mVpp, with the highest spectrum amplitude at around 100MHz.
Similar symptoms have been well documented when signals on a DUT are polluted with common mode noise. Scope manufacturers warn in their literature about this effect and often provide probe accessories to allow shorter ground connections, for example, the spring ground clip that comes with the Owon probes. Common mode noise is normally invisible to the scope, which is designed to view differential mode signals. However, because the 6" ground lead causes an impedance imbalance due to its inductance, the common mode noise is converted to differential mode noise, which is then naturally displayed by the scope.
The disturbing fact in this case, is that the common mode noise originates within the Owon, and even when viewing signals from a clean DUT, the user is deprived from the convenience of using the 6" ground lead. Member rf-loop, which is also an Owon dealer, was the first one to identify the SMPS and peripheral DC/DC converters as the culprits. To help members determine if their scopes had this problem and to what degree, a methodology accessible to most users was devised to check/test the ground noise. This basically involved using the scope probe set to X10, and connecting both the tip and the 6" ground lead to the scope's ground lug. The scope was then set to 50mV/div, 100us/div, maximum sampling rate, and several other details, before taking a reading. See the following post for all the details:
https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/msg255469/#msg255469 (https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/msg255469/#msg255469)
Several approaches toward minimizing this problem emerged from a number of our members with varying degrees of success. My approach was to try and mitigate the noise at the source by altering the circuit so it wouldn't cause so much noise. For my purpose, I was satisfied with the results. But many other members obtained similar results using other approaches, and Owon obtained similar results with the new PSU and a mod to the adapter board. None of these provided a perfect solution, but the noise was reduced to the point that it was possible to view low level signals while using the 6" ground lead.
I attached a few PDFs that were particularly helpful to me. If you are interested, next I can post images of some of the test results, like before and after noise levels.
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Hi Tomc,
I' sorry but I think that you want to qualify a 'deplorable state of affairs' (got it from the Dictionary) and what the heck should that help as we already know what's it's cause.
It's like counting the red spots after somebody got the measels instead of giving the right medicine.
You qualify and count red spots if you want to optimize a thing not when you have a basic, well known and documented problem.
At 100MHz a short piece of wire acts already like a coil. So what does it help using probes to qualify the prob here. It might help to find out that there is a prob but thats it.
What you explaind is absolutely right - common mode / differential mode - but is again just a refined description of the problem.
You know a machine radiating HF is like a transmitter. you have antennas, traps, ample return pathes, stray capacitances/inductivities and whatever. It will act differently if you move it from a desk made out of dry plastic to a desk made out of wood that stood before outside in the rain.
Radiation return path takes place through the mains cord but also through the electrical/magnetical fields. All of this has absolutely chaotic nature here!
If you do not want a machine to act as a transmitter kill or shield the source of the signal that makes this machine act like a transmitter not qualify how good or bad it acts as a transmitter.
Concentrate on what has to be done to make the thing work fine.
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Hi TomC,
to reply to you first question:
I already wrote that in one of my first posts I think, after each step I made the noise got down. I did not take any readings because as long as there is reduction after every step made I know I'm on the right way, and the noise was so high and unpredictable that, as I already pointed out I didn't feel like wasting my time with qualifying something I do not want (I love to qualify good behaviour though).
But to make myself clear for not to be missunderstood, of course you need to qualify problems if you want to claim refunding or compensation for damage, malfunction or bad workmenship towards the seller/manufacturer (I'm not so good in leagal english but think you know what I mean).
One more thought came to my mind and that is that I have the feeling that you wanted to find THE ULTIMATE SHORTCUT through witch simply by replacing ar adding a few cheap components the problem will be solved.
And I tell you and I'm pretty sure about that, it doesn't exist.... here we have to go the hard way!
Please forgive me...
P.S.: But you already said that you think I'm on the right way...
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....and please can everybody check the I/F or Adapter PCB for the marking on the controllers (ICs) of the backlight and display supply switchers. I would need the datasheets and already searched the net but there are many smaller companies who do chips like that. So far I have not found any who matches somehow partly the code/markings on mine and I hope that OWONS out of other production time have either chips with different markings or equivalent chips from other companies or non coded markings or whatever might help to identify them.
The backlight controller is quite simple but has an control input that is connected to the main PCB. I guess it is for the intensity control. Without that it could be replaced easily. Or one would have to check the format of the control signal and then look for a replacement.
And the display circuit is the most complex circuit of these switchers as I already mentioned.
The location of these ICs is upper right where the two wires (black and red) to the display are connected and bottom right where the ribbon to the display is connected.
The marks on the chips in my machine are:
upper one: OBT 24J PDVH
lower one: 1780 TB51
So please guys collect information if you can spent some time supporting my approach.
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Isolation of power sources have already done ... was the noise from the LCD screen ...
https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/1455/ (https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/1455/)
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https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/1500/ (https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/1500/)
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nothing against what you say - it depends on the way the ground distribution is done.
Yes, the location of each component is critical.
Another thing that must have been designed/decided by a dev engineer who rather should be kept away in an assylum for mental cases.
Poor man, I prefer to think that he did not know what he was doing.
And of course I noticed already the noise radiated from the display but there is no way to say anything defenitely about that as long as these many connecting lines between Main PCB and display all running along on the I/F PCB in close vacinity under 4 of these little switchers. This I/F PCB acts as a perfect coupling device to make sure that all spikes are properly distributed over the entire machine.
Do you mean that are coupled with the DC/DC EMI? Right?
You see the display itself works at a relatively low voltage level signalwise, haven't checked that yet - perhaps around 3V whereas the switchers work from 8.4V and some amps are flowing.
So what would you guess makes more noise, a bunch of low current / low voltage signals or high current square waves at up to 8.4V.
Sure, but please, don't underestimate.
And should the radiation going out from the front of the dislay be too much for you you get yourelf one of this conducting but transparent microfabrics that Tek offered as an option for all of its scopes for environments that are highly sensitive to noise radiation. You know, a normal CRT radiates as well out of the screen a little...
That has been also taken into account earlier in this post, not cheap.
I think we can handle all of this.
Hum... I'm not so sure, I can assure you that that is not easy.
And after we have designed a small pcb for all the little switcher beasts and put them inside of a small tin box that will be screwed through isolated posts above the I/F PCB with no noise going outside of this box and the outputs connected with if you want shielded cables to where the voltages should really go I'm sure we have that thing cured.
Hopefully!
I already got rid of this problem. I sold mine to a vehicle repair workshops, with new boards (Owon original improved versions).
And, I tell you if this spreads around the price for this machines will fall and whoever feels like may offer a kit with all inside what we did (will not be me for sure will be off to new shores then) to convert this bastard to a decent device.
You forgot the software and firmware. Among other things...
Just search ebay for this owons as I did recently. Countless offers came up. Piles of this machines must be out waiting for uninformed buyers. Do you know what I means....?
Sure, I know...
The marks on the chips in my machine are:
upper one: OBT 24J PDVH
lower one: 1780 TB51
See attachments. ;)
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Hi Tomc,
I' sorry but I think that you want to qualify a 'deplorable state of affairs' (got it from the Dictionary) and what the heck should that help as we already know what's it's cause.
It's like counting the red spots after somebody got the measels instead of giving the right medicine.
You qualify and count red spots if you want to optimize a thing not when you have a basic, well known and documented problem.
At 100MHz a short piece of wire acts already like a coil. So what does it help using probes to qualify the prob here. It might help to find out that there is a prob but thats it.
What you explaind is absolutely right - common mode / differential mode - but is again just a refined description of the problem.
You know a machine radiating HF is like a transmitter. you have antennas, traps, ample return pathes, stray capacitances/inductivities and whatever. It will act differently if you move it from a desk made out of dry plastic to a desk made out of wood that stood before outside in the rain.
Radiation return path takes place through the mains cord but also through the electrical/magnetical fields. All of this has absolutely chaotic nature here!
If you do not want a machine to act as a transmitter kill or shield the source of the signal that makes this machine act like a transmitter not qualify how good or bad it acts as a transmitter.
Concentrate on what has to be done to make the thing work fine.
Sorry if somehow I managed to push your buttons! :( It wasn't my intention, just trying to explain what I see the best way I can! :)
I'm just going to give you a sample of what I'm talking about using pictures and let you be the judge! The first two pictures were captured using the ground noise test setup previously described. The next two pictures were taken by scoping the output of an RF generator set to 30MHz 35mVpp. Beyond that frequency I don't recommend using the 6" ground lead provided by Owon because the tank circuit formed by its inductance and the probe's input capacitance starts to affect the amplitude of the signal. The last picture was taken by scoping the output of the RF generator set to 92MHz 280mVpp.
#1 - The noise exhibited by my SDS7102 as it was received from the factory, no modifications.
#2 - The noise as it appears today, with the original PSU with two modifications, a hand wound toroid and a belly strap. There is also a ferrite on the
ribbon cable, and the probe cables are also equipped with ferrites.
#3 & #4 - Illustrates the scope's performance when viewing low level signals, #3 with the 6" ground lead, and #4 with the spring ground clip. Note
that the amplitude on #3 is a little higher because at this frequency the tank circuit starts to affect it. I don't have equivalent pictures from
when the scope was unmodified, but I remember that it was impossible to even get a stable trigger due to the noise.
#5 - Illustrates the difference in signal amplitude at the tank's resonant frequency. CH1 is connected to the RF generator via the spring ground clip,
Ch2 via the 6" ground lead.
Personally, I'm satisfied with these results. Of course they are not perfect, there is still a little ground noise, but it no longer hinders my ability to use the scope to view low level signals when I choose to use the 6" ground lead.
I think it's commendable that you are trying to get rid of all the noise, I don't know if it's possible, but I sure would like to see how far you get. So good luck with it.
By the way, the LCD panel is large source of radiated noise, but it's only a problem if you get the probe cables close to it. In my case, with the probe cables equipped with ferrites this effect is mitigated quite a bit.
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Hi TomC!
Personally, I'm satisfied with these results. Of course they are not perfect, there is still a little ground noise, but it no longer hinders my ability to use the scope to view low level signals when I choose to use the 6" ground lead.
This result is more than acceptable.
In addition, how you get rid of all the noise sources that don't come from the oscilloscope?
By the way, the LCD panel is large source of radiated noise, but it's only a problem if you get the probe cables close to it.
Quite so!
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In addition, how you get rid of all the noise sources that don't come from the oscilloscope?
Hi Carrington,
Glad to see you active on this thread again! :-+
I didn't really completely get rid of outside noise sources, but quite a bit of it is mitigated by the ferrites on the scope probe's cables. I keep them there permanently and even in the vicinity of my computers or laptop the noise pickup is small compared to no ferrites. However, for the capture of Noise Today, the scope wasn't too close to other equipment. Otherwise the noise level may range a little higher but usually under 30mVpp.
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Hi everybody,
first, thanks a lot for the sheets. will check them later as I'm busy now.
But briefly,
TomC,
I respect you findings and results. I just have to confess that it makes me a bit crazy reading things like above from you and at the same time knowing what fine engineer you are by having read your paper.
But I know often in life you have no other choice than to look for good compromise out of various reasons. And you have family and I respect that even more!!!
To tell you the truth, I'm an idealistic maniac, my life is ruled by finding the truth and success through it. Got divorced - of course love women - but if I had do decide between a new challenge and a woman I go for the challenge (after a while). Didn't care for my son as I preferred to went on tour with my band as a musician, Worked for Tek and became a top troubleshooter, went away produced and still produce LPs/CDs, compose, develope and repair electronics, had a time when I was programming, even was a dope dealer for a while, and had the best stuff and excellent high class customers (25 years ago).
But also meditate since 40 years and practise Tai-Chi and study buddistic literature.
(don't know if I should post that at all)
Bought my first scope 45 years ago - a Hameg I still use for monitoring the outputs of my self designed millivoltmeters for audio tests. A scope is an extension of my brain and it has to be as perfect as possible.
So once more: YOU DO NOT DECIDE THE LENGTH OF THE GROUND LEAD YOU USE ON YOUR PROBE ACCORDING TO THE NEEDS OF YOUR SCOPE BUT IN ACCORDANCE TO WHAT MEASUREMENT YOU HAVE TO TAKE!
If you can live with it no problem for me, but in everydays work you will have to face the limitations sooner or later. And in a serious technical discussion it's just not very helpfull.
As to the argument that the display supplies already have been removed I can only repeat myself in a way and say, naive, because only removing/shielding this or that switcher is not enough. All of them have to be removed and shielded and filtered, no way around.
And finally for now, yes of course, just keep the probe away from the display then it's radiation frontwise should be no problem.
Thanks a lot for accepting.
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So once more: YOU DO NOT DECIDE THE LENGTH OF THE GROUND LEAD YOU USE ON YOUR PROBE ACCORDING TO THE NEEDS OF YOUR SCOPE BUT IN ACCORDANCE TO WHAT MEASUREMENT YOU HAVE TO TAKE!
If you can live with it no problem for me, but in everydays work you will have to face the limitations sooner or later. And in a serious technical discussion it's just not very helpfull.
I'm not sure what you mean by the capitalized statement, which usually indicates that the writer is shouting at the top of their lungs in frustration or anger!
If you think that I'm proposing that the ground lead should be shortened to accommodate the scope's shortcomings, then you have misinterpreted post #2409.
If you think that you should be able to use a long ground lead for HF or fast rise time measurements and still get accurate results, then you may benefit from re-reading the post and/or some of the attached excerpts from a variety of sources. Even after you rid your 9302 from the last vestige of noise, or any scope for that matter, that concept is just a physical impossibility.
The jest of post #2409 was in fact to demonstrate that the modifications at that particular level now allow my scope to work with a 6" ground lead the way it should have worked when I first received it. But still within the same limitations that apply to any other scope. These limitations are not dictated by the scope's performance, but are inherent to the characteristics of passive scope probes. Particularly X10 probes.
I provide this information because I believe it to be accurate, potentially helpful to other members, and consistent with the subject and the technical discussion prevalent on this thread. I'm sorry that you don't feel that way, I wonder if other members feel the same way!
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Hi BBAAHHOO,
thanks a lot for the links to your posts ++
now had the time to look at them a bit and got me your pics and schemes, Later will check them.
Question: Did you also reingeneer/retrace the display supply (not the backlight)?
Would help me if you already have the scheme.
And I guess all of you didn't check that there is another switcher on the main PCB doing the 1.9V.
(still havent read through all of this mass of information here - so I appologise if I missed it)
Greets to Russia, Sarasir
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Hi TomC,
sorry, sorry, sorry, I certainly do not want to shout at you, but thought just to highlight it as a basic rule. Please believe me I did not know that it means shouting.
Ok, I will go through you post once more and reply later in detail - maybe that I missunderstood it.
Respect
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Hi tomC,
just reading your post with the pics.
Please can you make a pic series using setup of pic #3 (a bit more amplitude would help) and sweeping the generator from say 50KHz up to say 150Mhz or max to see how much the cores on your probe and the ground lead 'tank circuit' affect the frequency response. A fast rise squarewave test at perhaps 100KHz to 10MHz would also do I think, but don't know if you have such a generator. And please care for correct termination on the output of your generator(s). (If the generators output is 50 Ohm put also a 50 Ohm termination before connecting the probe.
And please do the test twice with the probe in x1 and x 10 mode.
And it would be of good practise if you do the tests first of all as a reference with the generator(s) connected through a BNC cable directly to the scope with enough amplitude so that 'noise << signal'. Here the termination has to be on the scope side of the cable (Generator -> BNC cable -> termination -> scope).
Thanks
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Hello everyone. Once again - native sources. Just moved and added a filter. Food by the LCD screen native - on a separate board ... as the noisiest. A 1.9V power to the noise is not much compared with by the LCD screen does not touch him ... :)
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Hi BBAAHHOO,
how did you check that the contribution to the noise by the 1.9V switcher (converter) is not so much? Have you removed it from the main PCB?
And have you removed all other switchers (converters) from the adapter PCB?
If not:
Have you ever checked with another scope and a probe tip shortened with the ground lead that is placed directly to the top of a little switcher coil how much voltage/spikes will be induced into the ground lead? (preferably the +3.3V and 5.6V coils) (rethorical question as have checked that already!)
Are you aware that the runs (wires) (on the Adapter PCB) to the LCD screen are running along directly under the coils of the switchers.
Don't you think the same voltage/spikes induced into the ground lead will also be induced on the other side of the coils into the display lines?
And how do you think is the relationship between the native display noise and the one induced by the switchers - in case noise should be induced at all?
I could not test that yet because only today I removed the last switcher from the adapter PCB and now I can not power up the scope until I have brought it to work again and have it put in a tin box for shielding (also the backlight switcher I have only removed but not rebuild yet).
I think an indicator that it could be more or less like that is the ferritte core that OWON put over the printed ribbon connecting the display lines.
Hope you understand my english (I'm german).
good luck
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Hi tomC,
just reading your post with the pics.
Please can you make a pic series using setup of pic #3 (a bit more amplitude would help) and sweeping the generator from say 50KHz up to say 150Mhz or max to see how much the cores on your probe and the ground lead 'tank circuit' affect the frequency response. A fast rise squarewave test at perhaps 100KHz to 10MHz would also do I think, but don't know if you have such a generator. And please care for correct termination on the output of your generator(s). (If the generators output is 50 Ohm put also a 50 Ohm termination before connecting the probe.
And please do the test twice with the probe in x1 and x 10 mode.
And it would be of good practise if you do the tests first of all as a reference with the generator(s) connected through a BNC cable directly to the scope with enough amplitude so that 'noise << signal'. Here the termination has to be on the scope side of the cable (Generator -> BNC cable -> termination -> scope).
Thanks
Hi Sarasir,
I don't have access to a sweep generator to properly check the frequency response. I've been retired for 20 years and electronics is now just a hobby, so I can't justify expensive equipment although I very much want to have it. When I first started using the ferrites on the probes one other member suggested that they may affect the frequency response because of the added inductance. I remember manually tracking the response of two probes, one with ferrites and one without, first with my audio generator that goes to 100kHz, and next with my RF generator that tops out at 110MHz. The amplitude of the signal was identical at all generator frequency settings. I can't find the post now and I don't remember if I posted pics, I could re-create this again later on and capture some pics at specific frequencies if you want to see it.
I did find a post with more examples using the same setup as #3, but I don't think that it's exactly what you are looking for.
https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/msg275721/#msg275721 (https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/msg275721/#msg275721)
I also have an oscilloscope calibrator with a fast risetime (<4ns) output, but it's designed to connect directly to the BNC with a terminator built in within the male connector. So I'll have to connect the scope probe to that, first with the 6" ground lead and next with the spring ground clip to see the difference in the signal. I can also try with the probe set to X1, but I don't think there will be much difference between the two setups in that case because of the 6MHz bandwidth. Probably shouldn't have made that prediction, half the time my predictions turn out to be off or dead wrong!
OK, I have a few other things to do right now, but I'll probably try the oscilloscope calibrator in a little while and post the results.
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The attached images were captured while viewing the fast rise output (<4ns) of my scope calibrator. The calibrator's frequency was set to 1MHz and its output is around 250mV. The intent is to illustrate the effect of different probe configurations on the displayed signal.
#1 & #2 - These two images were obtained with the calibrator's output directly connected to the scope's BNC. These can be considered to be the most faithful representation of the output signal and can be used as a reference to gauge the amount of distortion introduced by the probe configuration in the remaining images. Note that the time base is set to 2ns/div and the rise and fall are within specs.
#3 through #6 - These were obtained with the probe set to X1, first using the 6" ground lead and next using the spring ground clip. Because the probe's bandwidth is only around 6MHz when set to X1, the higher frequency components of the signal are severely dampened before they reach the scope's BNC. As a result the displayed signal has a much slower rise and fall time. Under these conditions the effect of the 6" ground lead versus the spring ground clip has a negligible effect on the displayed signal. This may be construed as an indication that the 6" ground lead can be used when working with lower frequencies and/or slow rise times without risking signal distortion. Note that the time base is set to 20ns/div. Due to the slow rise/fall time the displayed signal would not fit in one screen at 2ns/div.
#7 through #10 - These were obtained with the probe set to X10, first using the spring ground clip and next using the 6" ground lead. In this case the probe's bandwidth is around 100MHz and the higher frequency components of the signal are not dampened before they reach the scope's BNC. As a result the displayed signal has a rise and fall time that closely resembles the direct BNC connection. Under these conditions the effect of the 6" ground lead versus the spring ground clip has a much more pronounced effect on the displayed signal. This may be construed as an indication that the 6" ground lead should not be used when working with higher frequencies and/or fast rise times if minimizing signal distortion is important. Note that the time base in this case is set again to 2ns/div.
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Hi TomC,
I agree with your interpretation. And there is practically no differenc between BNC directly and via probe recognisable. Just a little and that is rather the probe than the ferrite core I would say. The only thing that is maybe left to test is the influence of the ground lead with and without core but I don't think there will be much difference.
As I alredy said, I respect your remedy and for a user who does not need other setups it is certainly a simple and cost effective solution.
But for resellers and people like me who on one side are frequently working with different types of probes (I have several active- and differential-, one HV, and also some active and passive current probes), and on the other side also have to be able to feed low level signals directly into the BNC of the scope it's practically impossible to adopt that as a permanent solution.
But I understand absolutely. I would nobody just like that recommend to go the way I chose. To reconstruct in a way the whole power design of this machine with all the mechanical effords connected that is only for maniacs like me.
Soon I will post the pics of my reconstructed shielding of the input circuit and also the display power scheme. Took me more than two weeks - about 4 houres a day - to get done with it (had to cut 22 1.4mm threads - I tell you, after your nerves are also done)
And one more fact. On a 350MHz scope I think it's probably not so advisable to 'slow down' the probe with a ferrite core. You know the ringing caused by the spikes is generally above 100MHz so it doesn't bother you so much probably.
Yeterday I removed the display switcher and now the Adapter PCB is depopulated switcherwise. Once got the datasheet(s) from Carrington (thanks a lot once more) is was quite easy to get the scheme. OWON didn't use all options the application circuit offered so perhaps in a few days I can do my first test with all SMPS removed from the scope. I'm looking forward to see the result and especially how much noise was induced by the switchers into the display lines running underneath.
Will report here immediately then.
And, I asked you alredy once but you obviously forgot: Can you please explain in short the mechanism of the belly strap you added. I think it's used often on transformers if I'm right - a chopper band around the outside - but cant' remember having seen that on power transistors or FETs. Have to admitt have not yet read the additional literature concerning denoising perhaps it's in one of these.
And all that basic scope + probe papers - Thanks a lot but actually have many like that from Tek.
But you never know, every book has at least one ore more things explaind in a new way so you eventually understand again a bit more.
Thanks a lot so far and please cross you fingers for me not to send any of those chips to heaven.
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And, I asked you alredy once but you obviously forgot: Can you please explain in short the mechanism of the belly strap you added. I think it's used often on transformers if I'm right - a chopper band around the outside - but cant' remember having seen that on power transistors or FETs. Have to admitt have not yet read the additional literature concerning denoising perhaps it's in one of these.
Sorry about that!
I'll be 69 in a few days and have a wife 13 years younger that keeps me hopping!
Once in a while my brain skips a beat trying to keep up!
Here is a link to where I wrote about that:
https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/msg312258/#msg312258 (https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/msg312258/#msg312258)
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Hi to everyone, specially to TomC & Carrington.
I see that the member Sarasir had doing a lot of interesting work about eliminate the noise floor of this scope.
Personally, I have stopped the development about noise issue, after the last psu and adapter board changed.
For a long time ago, I will wait a fw development from Owon.... :=\
Now, I see that they give us the version 3.4 but for only newer s/n scopes !
Copy from their site:
SDS7102UP3.4
29 May 2014
The firmware applied to the products with following production batch / serial no. -
SDS71021312xxx, SDS71021319xxx, SDS71021327xxx, SDS71021344xxx, SDS71021352xxx, SDS71021407xxx, SDS71021414xxx, SDS71021418xxx,
Change log - :
1. XY mode - persistence function added ;
2. waveform refresh rate improved ;
3.waveform cutting/ recalling function added;
4. autoset - waveform recognition;
5. channel invert bug fixed;
6. probe attenuation compensation;
7. recorded waveform exported to USB drive
8. automatic measurement - 4 more options available
9. vertical position over-speed movement bug fixed
Have someone, any kind of information what is happening with the older s/n?
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Hi lemon!
Glad to see you back in the thread! :-+
I just downloaded the firmware for my unit: 1246xxx and in the upgrade instructions I see the following:
SDS7102? 1122xxx?1127xxx?1137xxx To V2.5.1.*
1143xxx?1149xxx?1152xxx?1153xxx?1203xxx?1209xxx To V2.8.1.6
1211xxx?1219xxx?1223xxx?1234xxx?1240xxx?1246xxx?1251xxx?1303xxx?
1312xxx?1319xxx?1327xxx?1334xxx?1344xxx?1352xxx?1407xxx?1414xxx?
1418xxx To V3.8
Haven't installed it yet, but apparently for anything higher than 1211xxx you get version 3.8.
Don't remember what version is your unit but I think you said it was purchased 2012.
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Nice to see you TomC again :-+
By the way, my wishes for your birthday (soon)...to be very well with your family.
I am looking about fw, with yours serial and the result was the same Ver. 3.3!
You have downloading and installed the fw to your scope or downloading only and saw some txt file?
You have fine memory, mine was 2012 series (1211xxx).
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....
Haven't installed it yet, but apparently for anything higher than 1211xxx you get version 3.8.
Don't remember what version is your unit but I think you said it was purchased 2012.
Sorry, now I see it!
What you are thinking about installing?
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Hi TomC
ahhh, 'TR1' is transformer 1 - OK thought 'TR' means Transistor as the designation for Transformers is usually just 'T'... Everything's clear now. Thanks a lot. (Yeah, keep up with the 'young' lady - Have had that a view times but already feel too old for at nearly 64!!! Need my slow and easy going. But respect)
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Sorry, now I see it!
What you are thinking about installing?
Installed it a little earlier and I got version 3.8 now. Haven't checked all of it yet but I see some new features, for example, persist now works in XY mode, which is something I complained about when I was trying to use it with my curve tracer.
Recently bought a Hantek 6022BE PC scope because I thought I could use it exclusively for the XY function (paid only US 70.00 for it), but although it's advertised as being a 20MHz scope it really can only handle about 5MHz well. So even in XY mode the definition is poor, the Owon, even without persist mode, is much better for that function.
So now I'm thinking that I'll use the Owon with my curve tracer and take the 15MHz Tek CRO I had dedicated for that function off my desk. I'll have to build a variable voltage divider so I can properly calibrate the Owon for use with the curve tracer, unfortunately the fine V/div adjustment that we have been complaining about for a long time is still missing in this new firmware.
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Nice to see you TomC again :-+
By the way, my wishes for your birthday (soon)...to be very well with your family.
I am looking about fw, with yours serial and the result was the same Ver. 3.3!
You have downloading and installed the fw to your scope or downloading only and saw some txt file?
You have fine memory, mine was 2012 series (1211xxx).
Sorry Lemon, I didn't catch what you were trying to tell me with the pic when I first read your post, yes, that's the firmware I downloaded, and even though it says V3.3, it's the same file that is used for the later models listed as V3.4. That V3.3 is what I installed on my scope, but it gave me version 3.8, with apparently all the new features that the change log lists for the older newer models. Don't know why Owon makes the listing so confusing, it appears that the same file is used for the whole SDS line.
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And one more fact. On a 350MHz scope I think it's probably not so advisable to 'slow down' the probe with a ferrite core. You know the ringing caused by the spikes is generally above 100MHz so it doesn't bother you so much probably.
As far as the conductive GND noise (common mode noise) generated within the Owon, the ferrites on the probe don't make a noticeable difference. If I keep the probe cable away from the LCD, turn off fluorescent lights, computers, and other test equipment, or at least keep the probe cable a good distance away from them, the GND noise test results are nearly identical with or without ferrites on the probe cables. However, the difference is apparent when these outside sources of radiated EMI are active and in the vicinity of the probe cables. So I don't see the ferrites as part of the solution for the conductive GND noise generated within the Owon, rather, they are a way of mitigating the effect of externally radiated EMI generated by other devices. The only exception I know off is the Owon's LCD screen, which has a strong near field of radiated EMI, and can cause the displayed GND noise to go off the screen if you get a probe cable without ferrites near it at the right angle. I've seen the same effect by getting the probe cable near a poorly designed laptop power brick.
In theory ferrites on the probe cable act as a common mode choke and shouldn't affect the differential signal at the probe's input, I've been able to prove this to my satisfaction to 110MHz (the max of my RF generator), but beyond that I can't be certain. I'd like to see someone with more sophisticated equipment test this further.
Although the SDS7102 is sold as a 100MHz DSO, according to tests done by member rf-loop, the front end is capable of nearly 200MHz before the 3db attenuation is apparent right off the box. So in reality, with it's up to 1GS/s sample rate, the scope is usable to well beyond it's 100MHz rating. However, the probes shipped with it are 100MHz, and that's all I have for now. I'm not sure how the GND noise symptoms would manifest themselves with higher bandwidth probes, and of course, I'm also very curious how the GND noise would look like on a 300+MHz scope like yours. I really wish you'd taken some pictures before making all the mods and shared them here. Too late now!
Thanks a lot so far and please cross you fingers for me not to send any of those chips to heaven.
I know what you mean, I had an accident while doing tests on my scope's PSU and smoked the PWM controller, the mosfet, the 4 sense resistors connected to its source, and the common mode choke (LF1). Had to ask Richtek to send me a sample of the PWM controller because I couldn't purchase a replacement locally. However, at the time, I had the new style Owon PSU in my scope and was conducting the tests on a test fixture with dummy loads. You are pretty gutsy to do these modifications without backup spares, so I'll keep my fingers crossed and wish you good luck!
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Hi to everyone, specially to TomC & Carrington.
I see that the member Sarasir had doing a lot of interesting work about eliminate the noise floor of this scope.
Personally, I have stopped the development about noise issue, after the last psu and adapter board changed.
For a long time ago, I will wait a fw development from Owon.... :=\
Now, I see that they give us the version 3.4 but for only newer s/n scopes !
Copy from their site:
SDS7102UP3.4
29 May 2014
The firmware applied to the products with following production batch / serial no. -
SDS71021312xxx, SDS71021319xxx, SDS71021327xxx, SDS71021344xxx, SDS71021352xxx, SDS71021407xxx, SDS71021414xxx, SDS71021418xxx,
Change log - :
1. XY mode - persistence function added ;
2. waveform refresh rate improved ;
3.waveform cutting/ recalling function added;
4. autoset - waveform recognition;
5. channel invert bug fixed;
6. probe attenuation compensation;
7. recorded waveform exported to USB drive
8. automatic measurement - 4 more options available
9. vertical position over-speed movement bug fixed
Have someone, any kind of information what is happening with the older s/n?
Arrghh! Some of those features would have been useful to me. Too bad Owon decided to replace my 1211 main board with a 1209 one when I sent it for repairs. After installing the update, I got firmware version 2.8.1.6 and check-sum o B0BB1638, same as before, so no new features for those with older units.
Anyway, it's nice to see some new activity in this thread! Thumbs up :-+ for very detailed and very educational content!
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Nice to see you TomC again :-+
By the way, my wishes for your birthday (soon)...to be very well with your family.
I am looking about fw, with yours serial and the result was the same Ver. 3.3!
You have downloading and installed the fw to your scope or downloading only and saw some txt file?
You have fine memory, mine was 2012 series (1211xxx).
Sorry Lemon, I didn't catch what you were trying to tell me with the pic when I first read your post, yes, that's the firmware I downloaded, and even though it says V3.3, it's the same file that is used for the later models listed as V3.4. That V3.3 is what I installed on my scope, but it gave me version 3.8, with apparently all the new features that the change log lists for the older newer models. Don't know why Owon makes the listing so confusing, it appears that the same file is used for the whole SDS line.
Exactly, the fw 3.3 for our series upgrade to 3.8 like fw 3.4 for the newers serial Numbers.
What a strange fw politic!
Sometimes, they improved the fw have the same number, but change the data of uploading file :palm:
Owon all the times are confuse us!
Just, I installed the new fw and here are my notes:
1. XY mode - persistence function added
- I don't look it
2. waveform refresh rate improved
- Seems to be some improvements cause changes at Autoset.
For that reason I repeat the test of Mark Madel (Owon SDS7102 review. youtube) with the trigger output capturing at Chanel II.
The Mark has found that this DSO varies the refresh rate depending time base & memory depth. He had recorded 22.96fps at 1MHz sinus signal (1K depth memory, 1us time base) that dropped to 16.43 when the memory depth was 10M.
With the same conditions, I repeat the test and the results seem to be very faster. With 1K depth memory the refresh rate was 119.07 and with 10M was 36.95. Nice to be good!
Please look at my attachment to verify.
3.waveform cutting/ recalling function added
- Now, at Save menu adding a type of "CutWave", the message that appearing now is "move cursors and press Save to save wave to Udisk. Recall wave btw two cursors by OWON generators".
In fact with this method saves data to .ota files that probably plays to Owon generators !!! :palm:
4. autoset - waveform recognition
- Here is the big differences.
Now when you pressed the Autoset button, the scope try to identify the waveform and if it is success then presents choices depends from what waveform is.
For sinus waveform there is continuous period sinewave or full one period and FFT.
For pulse or square waveform there is continuous pulses, one period, rise pulse, fall pulse
Triangle or something else doesn't recognized and no more choices are available.
Each time you set different waveform must to press the Autoset button to recognized it.
It is pitty that the FFT choice doesn't work with waveform together (split window)
Have in mind, that the Autoset works only if the Autoscale is OFF
5. channel invert bug fixed
- OK, it corrected.
6. probe attenuation compensation;
- Another automatic procedure for relaxing. Connect your probe to a stable 1KHz/5V and scopes makes a diagnosis if this probe has a good compensation or not.
7. recorded waveform exported to USB drive
- It seems to adding some sub-menus to record menu now.
8. automatic measurement - 4 more options available
- They added week rms, cursor rms, duty cycle and Phase?RP
Still is missing the all measurements to real time, just each time that you pressed the "Show All" button.
9. vertical position over-speed movement bug fixed
- It corrected.
Finally, there are some improvements with the more major to me the more stable function of Autoset.
Still missing basic functions like fine V/div adjustment, split window for zoom or fft and something else.
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2. waveform refresh rate improved
- Seems to be some improvements cause changes at Autoset.
For that reason I repeat the test of Mark Madel (Owon SDS7102 review. youtube) with the trigger output capturing at Chanel II.
The Mark has found that this DSO varies the refresh rate depending time base & memory depth. He had recorded 22.96fps at 1MHz sinus signal (1K depth memory, 1us time base) that dropped to 16.43 when the memory depth was 10M.
With the same conditions, I repeat the test and the results seem to be very faster. With 1K depth memory the refresh rate was 119.07 and with 10M was 36.95. Nice to be good!
Please look at my attachment to verify.
This old test give a little indication that the speed can increase, that there is room for improve wfms/s speed some amount but of course it is still conventional DSO, not DPO.
Nice that they have finded some solution for add speed by FW.
For rare peaks etc it is more fast than may think if look only continuous wfms/s speed.
It can rearm trigger faster and do one capture to buffer. But it can not of course repeat this cintinuously. But, for rare extra glitch this may find it more fast that may assume if look only continuous average wfms/s speed.
Here is this old test agen:
(http://img163.imageshack.us/img163/7417/owontst1k10mtrig.png)
(http://owon.forumup.com/viewtopic.php?t=183&mforum=owon (http://owon.forumup.com/viewtopic.php?t=183&mforum=owon))
I can see also nice new work and thinking about noise.
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Haven't read the whole thread :o (sorry) :P.. Any quick links to the firmware update?
Mine is SDS71021303xxx, I guess that means I should benefit from the latest firmware improvements.
Any high risk of bricking or anything I should be aware of?
(haven't done any updates yet as I've had bad experiences with firmware updates on other hardware, requiring days of poking around with JTAG to recover)
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Haven't read the whole thread :o (sorry) :P.. Any quick links to the firmware update?
Mine is SDS71021303xxx, I guess that means I should benefit from the latest firmware improvements.
Any high risk of bricking or anything I should be aware of?
(haven't done any updates yet as I've had bad experiences with firmware updates on other hardware, requiring days of poking around with JTAG to recover)
Link to Owon is below, click on Download Center:
http://www.owon.com.hk/main.asp (http://www.owon.com.hk/main.asp)
Done several upgrades on my unit without any problems.
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Hi lemon,
Thanks for the excellent analysis of the new firmware features! :-+
Doing something like that was next in my agenda, but you got it covered! :)
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I can see also nice new work and thinking about noise.
Hi rf-loop,
Nice to to see you active on this thread again! :-+
Any chance you can do some testing on the below when your schedule permits?
In theory ferrites on the probe cable act as a common mode choke and shouldn't affect the differential signal at the probe's input, I've been able to prove this to my satisfaction to 110MHz (the max of my RF generator), but beyond that I can't be certain. I'd like to see someone with more sophisticated equipment test this further.
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Arrghh! Some of those features would have been useful to me. Too bad Owon decided to replace my 1211 main board with a 1209 one when I sent it for repairs. After installing the update, I got firmware version 2.8.1.6 and check-sum o B0BB1638, same as before, so no new features for those with older units.
Hi AndrejaKo,
Nice to hear from you again! :-+
Have you tried writing to Owon about this?
I think their warranty states that they will replace defective parts with equal or equivalent parts. Using an older board that is no longer upgradeable doesn't seem to match that promise!
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Hi TomC,
just as a first reply to your long post above:
Yes I noticed that there where ouside sources of noise as well, e.g. my new LED bulbs (changed all my illumination to LED recently - it's great but would be worth it's own thred as there are different qualities on the market and some with and some without switching converters).
I minimized that by putting ferrite cores to the mains cables of the lamps as near to the bulbs as possible and not just one, 3 on each. (Fortunately I had a box full of that cutted cores types which are inside of a plastic enclosure that you can open and close again.)
I think it's best practise is to have an emission free working desk.
As to the terms Common mode and differential mode concerning Owons input I'd like to mention that it's not a perfect common mode input at all (at Owons BNCs). Only if you had a very strong generator with a floating output with zero impedance over the whole spectrum connected without any wire in between to the BNCs you cold assume a perfect -/+ signal fed to the input. And by using another scope with differential input you could get an idea what the Owon does to this signal common modewise by it' s emission and impedances. And if the characteristics of the generator's output (and a probe connected to the input is a generator as well if connected to a signal source) are changed various effects will be experienced. The most important to me is, that dependent on the generators output characteristics part of Owons emission will be changed in phase and level and in a way sent back to the input's center connector and then and only then of course will be displayed on it's screen.
And your cores no matter why you put them on are part of the game.
So far for now and until later...
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As to the terms Common mode and differential mode concerning Owons input I'd like to mention that it's not a perfect common differential mode input at all (at Owons BNCs). Only if you had a very strong generator with a floating output with zero impedance over the whole spectrum connected without any wire in between to the BNCs you cold assume a perfect -/+ signal fed to the input. And by using another scope with differential input you could get an idea what the Owon does to this signal common modewise by it' s emission and impedances. And if the characteristics of the generator's output (and a probe connected to the input is a generator as well if connected to a signal source) are changed various effects will be experienced. The most important to me is, that dependent on the generators output characteristics part of Owons emission will be changed in phase and level and in a way sent back to the input's center connector and then and only then of course will be displayed on it's screen.
And your cores no matter why you put them on are part of the game.
So far for now and until later...
Yes, I agree, everything is inter-related. Just like resistors are also inductors and capacitors in some ways, and transformers also act as capacitors, etc., etc. But in this imperfect world everything has a primary purpose!
Cheers! :)
PS. I thought you meant differential instead of common in your post, correct me if I'm wrong.
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Just got my curve tracer working with the SDS7102 in XY mode. I made a special interface cable with adjustable voltage dividers so I could perform the calibration procedure. This of course wasn't necessary with the Tek CRO because I could use the variable controls for that function. The first two attachments are captured images from the SDS7102, on the first one persist is turned off, which was the only option before the latest firmware release, on the second one persist is turned on. The third image is an older photograph of the Tek CRO I've been using with my curve tracer until now.
The persist option as implemented for XY mode is not perfect, the time settings don't seem to have any effect, and regardless which one you select, it seems to operate as if infinite had been selected. But a least I can obtain a usable image if I want to keep a record of curves for particular components. So I think I can now retire my Tek CRO from this job.
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Yes TomC,
I think indeed somehow I missed the point. I was in a hurry and did not think over what I wrote once more, and by the way, the grass is blue and the sky is green....
But seriously:
I discovered the noise problem by connecting a Tek SG505, a very low distortion sine generator for audio tests with a high level floating output to the Owon after having checked it's frequency response with a Tek SG503 (A sine generator up to 250MHz) and a SW503 (A sweep generator up to 500MHz).
With both the HF generators the noise was not disturbing, I can't even remember if I noticed it, but with the floating output generator it was terrible (filled almost the screen at 2mV/div input position.
I said to myself - sorry - fuck what's happening here and started to do tests and tried to build up a picture of what happens inside and around that Owon.
I don't know actually what I meant in my last post differential-, common mode or both. Now I see that it did not fit together at all and from your view your correction is of course right.
Let me put it another way and please tell me what you think:
1. We know that there is noise generated inside of the Owon that is also present at the ground contacts (BNC sleeve).
2. The noise must be also present at the inner contact of the BNC other wise we would see it on the screen, and we don't (nothing connected yet).
3. So, if I am right therefor this must be common mode noise provided you look at the sleeve as minus and at the center contact as plus, or?
4. The moment I connect a device that's not grounded by itself e.g. the floating output of the SG505 to the input the common mode noise seems to be or is actually converted into a differential one.
5. If I make a short directly at the input no change is to be seen.
So provided that you can agree so far, tell me please how would you explain and also test this effect?
(Only after you tried all roads you can tell which one is a dead end one.)
P.S.: yes, got me some samples from TI already but the controller of the display supply converter is from a smaller company I don't know if they are so generous as TI.
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2. waveform refresh rate improved
- Seems to be some improvements cause changes at Autoset.
For that reason I repeat the test of Mark Madel (Owon SDS7102 review. youtube) with the trigger output capturing at Chanel II.
The Mark has found that this DSO varies the refresh rate depending time base & memory depth. He had recorded 22.96fps at 1MHz sinus signal (1K depth memory, 1us time base) that dropped to 16.43 when the memory depth was 10M.
With the same conditions, I repeat the test and the results seem to be very faster. With 1K depth memory the refresh rate was 119.07 and with 10M was 36.95. Nice to be good!
Please look at my attachment to verify.
This old test give a little indication that the speed can increase, that there is room for improve wfms/s speed some amount but of course it is still conventional DSO, not DPO.
Nice that they have finded some solution for add speed by FW.
For rare peaks etc it is more fast than may think if look only continuous wfms/s speed.
It can rearm trigger faster and do one capture to buffer. But it can not of course repeat this cintinuously. But, for rare extra glitch this may find it more fast that may assume if look only continuous average wfms/s speed.
Here is this old test agen:
(http://img163.imageshack.us/img163/7417/owontst1k10mtrig.png)
(http://owon.forumup.com/viewtopic.php?t=183&mforum=owon (http://owon.forumup.com/viewtopic.php?t=183&mforum=owon))
I can see also nice new work and thinking about noise.
Hi rf-loop.
I was remembering your way to measure the refresh rate but I haven't two channel signal generator for this.
Unfortunately, my Hameg is one channel and the only way that thinking is the test of M.M
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Just got my curve tracer working with the SDS7102 in XY mode. I made a special interface cable with adjustable voltage dividers so I could perform the calibration procedure. This of course wasn't necessary with the Tek CRO because I could use the variable controls for that function. The first two attachments are captured images from the SDS7102, on the first one persist is turned off, which was the only option before the latest firmware release, on the second one persist is turned on. The third image is an older photograph of the Tek CRO I've been using with my curve tracer until now.
The persist option as implemented for XY mode is not perfect, the time settings don't seem to have any effect, and regardless which one you select, it seems to operate as if infinite had been selected. But a least I can obtain a usable image if I want to keep a record of curves for particular components. So I think I can now retire my Tek CRO from this job.
TomC, thanks for the testing.
It seems to be not to very fine but simple "well" this XY mode.
But, it seems like a dots type than vector, something like dots with a hi resolution (more dots). Of course the job is done!
I don;t know but 2 years and still we haven't Div/V adjustment.
Is it so difficult for this scope?
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Hi Sarasir,
The way I understand it, in theory, the common mode noise stays that way until it encounters an impedance imbalance in its path, the change in amplitude and/or phase at that point results in a difference of potential between the two terminals which is the definition for differential mode. In other words, the common mode noise now can be seen by the scope. For example, that is the effect of the 6" ground lead, in that it causes an impedance imbalance, and what before was in phase and at the same potential at the sleeve and inner conductor of the BNC, now exhibits a difference in phase and/or potential.
At this point I don't understand exactly what in the SG505 setup causes the imbalance. From your post I can tell that it was connected directly to the BNC, I presume with a coax wire and BNC connector. So it's not clear in my mind where the imbalance is taking place at. Maybe a schematic of the SG505 may help. I'll think about it some more, and in the mean time you let me know what else comes to mind.
The wife is impatient wants to go for a walk or bike ride, so I'll get back to you later on today, maybe with a better explanation.
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Link to Owon is below, click on Download Center:
http://www.owon.com.hk/main.asp (http://www.owon.com.hk/main.asp)
Done several upgrades on my unit without any problems.
Many thanks :-+
Update went without any issues.
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Hi TomC,
you made my day man, that's the term - impedance imbalance.
All consequences of that where whirling in my head for weeks, phase delays, frequency peaks and zeros but couldn't think of a common term. And once you have it it's looks so easy.
Thank you very much.
Had a look at the circuit of the SG505 and its basically just a sine generator, a phase inverter for the minus side, and two complementary push-pull power amps that drive the + and - outputs, with a switchable attenuator before each output. All power is supplied by a conventional power transformer through linear +/- regulators. The common of the whole circuit is connected to the front panel's CT connector as they call it and is not grounded but may be switched to ground (chassis/power cord ground) by a push button. Another Pusbutten (On/Off) disconnects the generator from the output amps, and by means of a switch, 50, 150 or 600 Ohm source resistance can be selected. None of the switches altered the noise displayed on the Owons screen. Only when I shorted the CT connector to the ground post on the front panel with a screw driver it went a bit down.
But don't want to bother you any more with that circuit - unless you are personally interested.
'Impedance imbalance' made everything clear to me, wow!!!!.
Yeah, loved also the bike rides along the river here with my last girl friend a few years ago. Over 4 years from heaven to hell and back untill I learned another expression that was not really new to me, but never cared about what it really means: manic depression. I just needed a break - was close to go down - and now I see it in every woman. Don't know when that will go away again....
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Hi Sarasir,
I found an SG505 manual on the web, the only thing I see that may had played a small role in the impedance imbalance is the capacitor with the arrow on attachment #10. But I don't think that can even come close to account for the near 40mVpp noise you described, specially at the 2mV/div setting since it has a 20MHz bandwidth limit. The only thing that comes to mind that may account for that kind of imbalance is an unterminated coax connection to the scope's BNC, because of reflections and standing waves. But I doubt that's what happened because you already mentioned how important proper termination is. So I don't know what else may have been involved, unless your 50 ohm terminator is open and you haven't noticed.
Anyway, I thought the subject of proper termination may be useful to other members, so I captured some images to illustrate my experience. For the attachments I used my audio generator set to around 100kHz, 10mVpp. This is not a sophisticated device like the SG505, but it can operate from a power brick or from 9V batteries. So for these tests I chose battery operation, so the output is floating, and at least we know some of the noise is not coming in via the power brick. Can't say the same thing for radiated emissions from other devices in my lab, couldn't turn off everything else for these tests, so at least some of the noise doesn't originate at the Owon.
Because the noise amplitude varies constantly it's difficult to illustrate with a static capture what is going on, so I decided to set the trigger to normal and set the trigger level as high as I could and still get an occasional sweep. That way it's possible to capture the highest noise examples. Because of this the trigger frequency may not show 100kHz even thought the generator is set to 100kHz.
Some of the captures were taken with a .01uF capacitor connected between the (-) post of the generator and earth ground. I just wanted to see if there was any difference with the capacitor in place and without it. The idea came to mind because the SG505 uses a similar capacitor when in floating mode and I wanted to simulate the effect that it may have.
#1 through #4 - Here I have the Owon connected to the audio generator via an unterminated coax. On the first two images the generator is off, on the next two it is on. Some captures show the noise with no capacitor connection to earth ground and some with a capacitor connection to earth ground. There seems to be a little more noise with the capacitor connected to earth ground. The bulk of the noise, however, is present regardless.
#5 through #6 - These are similar to the last two images but the coax cable is now terminated at the scope's end with a 50 ohm terminator. Don't know what happened to my in-line terminator, so I had to use a T and a cap terminator. Not the best arrangement but it shows quite a contrast with the no termination setup.
#7 through #8 - Here I ditch the coax setup and use a X1 probe instead, the lower bandwidth of the probe makes quite a difference as it rejects most of the remaining noise. Using the spring ground clip seems to give a small extra improvement.
#9 - Same setup as #8 but limiting the scope's bandwidth to 20MHz, seems like there is an additional small improvement in the noise.
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Yeah, loved also the bike rides along the river here with my last girl friend a few years ago. Over 4 years from heaven to hell and back untill I learned another expression that was not really new to me, but never cared about what it really means: manic depression. I just needed a break - was close to go down - and now I see it in every woman. Don't know when that will go away again....
Know exactly what you mean and had to learn every detail of what this disease, bipolar disorder, means over the years. My wife suffers from it since childhood, but the diagnosis didn't happen until a major manic episode over a decade ago. After endless therapy and medications, she is now free from psychotropic drugs and successfully controlling the ups and downs with fish & krill oil as well as yoga and exercise.
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TomC, thanks for the testing.
It seems to be not to very fine but simple "well" this XY mode.
But, it seems like a dots type than vector, something like dots with a hi resolution (more dots). Of course the job is done!
I don;t know but 2 years and still we haven't Div/V adjustment.
Is it so difficult for this scope?
Yes, even though you can select vector or dots, it's always dots, that didn't change with the new firmware. However, you can now select persistence and when enough dots accumulate on the screen to make a line you can stop the scope and capture the image. The thing is that you have to this manually because the time options don't do anything, dots keep on accumulating forever and eventually you have a very thick line. But it's better than before.
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Hi TomC,
your pics above show exactly what I had experienced. By the way, the SG505 I used has the high Level output (option 02) installed and in this version capacitor C1720 is not present. I guess the stray capacitance of the additional high level out PCB towards the grounded frame and shields replaced that in a way. I have to admitt that I didn't use any termination with the SG505 because it goes only up to 100KHz and here no reflection in the BNC cable needs to be considered. (Of couse I would use appropriate terms if had to check e.g. a 600 Ohm balanced audio line or 200 Ohm mic input of a mixing desk, but that would be only for correct leveling.) And, now as we know in a way what's going on here my recommendation would be to use a 50 Ohm temination rather on the Audio Generators side of the BNC cable because it's the Owon who is the generator of the HF spikes. Have you thought about that?
Even if I knew from working with the SG505 since decades that it is absolutely clean I simply connected it after experiencing the spikes over to my Tek 475A (250MHz analog scope) and the display was clean of course. Connecting both the Owon and the Tek in parallel to the SG505 also the Tek showed the spikes.
So I knew that there's something wrong with the Owon.
After a few more tests with different probes and cables I just started with checking through the Owon to find and kill the problem.
Also searched the web but found almost nothing - just one short remark in a review said that it's very noisy.
To the thread here I came by chance much later when searching for the datasheets of the last two switching controllers.
Your results by using the probes just verify the findings of your earlier tests with your HF generator and your probe.
Yesterday I got the Backlight switcher working in another small tin box and today I will start rebuilding the last one - the display supply.
You know as I alredy said I want to get rid of that noise entirely so to be able to connect in which way ever whatever I have to ckeck and do not have to deal everytime with these noise suppression considerations - but we know it's a long and hard way.
Yesterday when reading through the recomendations of the TPS61160A backlight switcher controller for denoising found an interesting remark about ceramic Cs. Didn't know that yet but also had no time yet to read through all denoising literature including the ones you posted.
I will come to that when I have the Owon working again and will focus on minimizing the noise and also component use. At the moment I'm more ore less using brute force to get every switcher clean.
-------------------------------------------------TPS61160A----------------------------------------------------
Datasheet, page 11:
Care must be taken when evaluating a ceramic capacitor’s derating under dc bias, aging and AC signal. For example, larger form factor capacitors (in 1206 size [3.2mm]) have a resonant frequencies in the range of the switching frequency. So the effective capacitance is significantly lower. The DC bias can also significantly reduce capacitance. Ceramic capacitors can loss as much as 50% of its capacitance at its rated voltage. Therefore, leave the margin on the voltage rating to ensure adequate capacitance at the required output voltage.
-------------------------------------------------TPS61160A----------------------------------------------------
And to the disorderly bahavior, my last girlfriend who has already been hospitalized once before I met her for the first time (what I only learned later through a neighbour who told me the whole story) would refuse any help... So what can you do?
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Hi Sarasir,
I debated in my mind with that concept, but since the Owon in this case is not just the source but is also used to view the signal, I looked at the coax as a kind of a probe, so I thought it would be prudent to have a terminator at the scope's end. It's basically what one would do if using a coax as a high frequency (low capacitance) X1 probe.
The highest bandwidth analog scope that I own is a Tek 453A (60MHz), I doubt I can see much of this noise with it, but I may dust it off and experiment with it a little later on.
I'm anxious and very curious to see how clean you can get the Owon with your mods, I hope you have the time to post some pics similar to the ones I posted when you get it as clean as possible.
Not much you can do if they refuse help, I'm glad my story turned out differently!
Edit:
On the other hand, if the objective is to see how much noise the Owon is producing, then of course you don't want to use a terminator at the scope's end. In this case this setup would be similar to the one we've been using in this thread with the probe tip and ground lead connected to the ground lug. Basically just to purposely create an impedance imbalance to make the common mode noise (GND noise) visible.
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Hi TomC,
Of course I will post them. Looking forward to it by my self.
-----Do not read this - only more preliminary thoughts.-------------------------------------------------------
the proposal I made to put the termination to the generators end was of course only meant for to see the difference concerning the noise displayed (I just forgot to add that), not at all as a general rule for every days work!
Actually I thought that if you put the terminator to the generators side - only in case of a non HF generator - the noise displayed should get less as the terminator would minimize the HF impedance imbalance of the generators output. But as I think about it again now there should be of course another terminator at the scope end as well (as the input otherwise would be 1 MOhm and so not correct for a BNC cable - I forgot that before) and the generators output switched to highest source imedance (like 600 Ohm at my SG505). But again only meant for testing noise behaviour. But wouldn't say much I think only the influence of the BNC cable in connection with the impedance imbalance of the generator would be cancelled out in a way.
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Was just another one of my unfinished ideas I always have on the way to true wisdom...
And I also forgot that the noise source is on the ground side of the BNC....
But now out of the above rubbish I think I have three statements that should be true (generator here is a non HF audio sine wave one):
1. The transfer of the noise signal from the scope to the generator happens initially through the shielding of the BNC cable (here the preliminary thought above was a dead end 'cause you cannot terminate the shielding - against what?).
2. And the BNC cable acts in its normal way then to bring back the result of the impedance imbalance in the generators output to the scope (only this part will be infuenced by correct termination) (...and not only the output but the entire generator circuitry might be involved more or less)
3. And as the shielding of the BNC cable is not at all a perfect medium for to transfer HF signals part of the noise will already be coupled to the inner conducter way before it reaches the generator including all the consequencies like impedance missmatch and reflection.
Can you agree with that?
And I'm glad for you too, cerntainly something if you stood that through with your wife.
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Hi Sarasir,
Trying to visualize exactly what's happening is not easy, I have some ideas, but that's all they are, no concrete proof and only scant evidence that they match reality! :palm:
So here is what I currently think, however at this point I'm not sure how to test or verify it!
The following is just a little background of things I think are pretty much of general knowledge:
As we know, most of this originates at the switchers. Due to stray capacitance, inductance, or due to radiation, some of the fast switching current strays from its main path and flows through an alternate unintended path to reach the return. These stray currents can be differential or common mode from the scope's input point of view. Owon has managed to clean up the differential signals with filtering to the point that there is a reasonably low amount of baseline noise, and a reasonably low amount of distortion on the signal path. However, some common mode currents are still present that are invisible from the scope's input point of view.
The following is what I think is happening inside the Owon in more detail but can't prove it:
So I believe that what remains are: a) Currents that are nearly identical in both phase and amplitude at both the sleeve and center conductor of the BNCs. b) In addition, as long as there is nothing connected to the BNCs, I believe there is an even larger number of current paths that are only present on the ground plane but are not referenced to the BNC's center conductor. Therefore these currents are also invisible from the scope's input perspective.
When you connect something to the BNC, for example, a probe cable or plain coax, I visualize a couple of long physically close parallel conductors analogous to long adjacent parallel traces on a circuit board. Since the shield is part of the ground plane, any currents on it that did not originally have a counterpart in the BNC's center conductor will be coupled to it. Assuming a perfect cable, the result will be common mode currents from the scope's input perspective, and as a result, these currents will still remain invisible.
The following tests out experimentally, but the reason why it happens is just my theory:
However, in reality, due to cable imperfections, I would expect a moderate but gradual increase in differential signals as the length of the cable increases. In other words, you would see a little more noise displayed on the scope as the cable length increases.
The following is just a little background of things I think are pretty much of general knowledge:
As the cable length increases propagation delays become more of a factor. This effect prevents distortion free transmission of differential signals, particularly HF signals, from one end to the other unless the cable is properly terminated to match its characteristic impedance. Improper termination will result in reflections that end up being added to the original signal. The resulting signal is a distorted version of the original signal.
The following seems to test out experimentally, but the reason why it happens is just my theory:
However, the signals of interest in this case are common mode, and the concern isn't signal distortion, instead, we'd like to know the mechanism that converts some of these common mode signals to differential mode signals. First consider a coax cable cut at the end with a sharp razor blade. To a signal this cable will exhibit an abrupt transition from 50 ohms characteristic impedance to nearly infinite impedance. However, because of the clean and nearly perfectly symmetrical cut, there will be little if any impedance imbalance in respect to the shield and inner conductor, so the reflections caused by the abrupt change will result in nearly identical currents, in both phase and amplitude, on both conductors. If the scope's input circuit is properly designed and laid out, an analogous effect will take place when the reflections encounter the 1 meg ohm input impedance. So any increase in visible noise given these circumstances should be small. In contrast, if for example, the coax ends in 1 or 2 inch pigtails, the increase in visible noise is quite a bit larger. There is still an abrupt change in characteristic impedance, but in addition, there is also an impedance imbalance because of the rather raw unequal imperfections at the end of the cable. I believe in this case reflections multiply the effect of the impedance imbalance at the end of the cable. Outside interference probably also plays a role in this scenario. Also, in my opinion, any equipment attached to the pigtails will also have an influence on the impedance imbalance and/or the characteristic impedance at the end of the cable.
I also believe that using proper termination, which we know produces the illusion that the cable has an infinite length and as a result minimizes reflections, will also minimize the multiplying effect that I believe an improperly terminated cable will have on impedance imbalances at its ends.
Anyway, that's the way I view the effect of proper termination as it relates to the increase in visible noise. But again, the main reason to use proper termination is to minimize distortion of the differential signals that traverse the cable on their way to another device.
How much of the above reflects the way that things actually work? I'm not sure, it sounds good to me at the moment. The only thing that I know for sure is that the visible noise is reduced when proper termination is used.
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Hi TomC,
things clear up more and more. Your analysis and explanation is very profound and I read it several times, just great.
A few thoughts and facts I found out I might add:
As to the noise transfer from the switchers inside I think that actually most of it takes place through the ground posts by which the respective PCBs (mostly the adapter PCB) are screwed to the main frame. The adapter PSU is held by 5 screws and one could say, to realy make sure that every switcher has it's direct connection to pass on it's noise.
(Only the little switcher on the main PCB has no direct connection to ground only through the grond plane of the PCB.)
I tested that with my Tek 475A by using a probe with very short ground lead. Connected the ground lead to the frame in different locations and moved around with the tip on the surface of the frame. Close to the ground lead there was no noise or very little, moving further away the noise increased remarkably, of course more or less depending on the location. Most increase per centimeter so to say I encountered in the area where the adapter PCB is connected to the Main PCB. The cut-through here for the connector if far to big resulting in a weak ground conduction.
It's no supprise at all that there is noise as well present on the BNCs. The whole frame is polluted and the return path takes place mostly through the electrical field(s) but also through the magnetical field(s) and the power cord I think. The whole thing acts like a radio transmitter with lots of little antennas all around.
A little detail by which you can see the struggle of Owons engineers is how the Main PCB is screwed to the frame (so in my model). The hexagonal spacer bolt between frame and input side of the main PCB is a plastic type. Only a few centimeters to the side where the trigger input is located they use a metal post. Consequenly there is a bit less noise on the input BNCs than on the trigger BNC.
But they had to connect the frame with the main PCB on the top side again with 2 metal spacer bolts.
You know out of my long time working with Tek and knowing their machines back then in and out, down to the last screw I know excactly how to deal with ground and shielding or in other words how things like this should be done. Noise on the ground is just inacceptable.
And to the use of termination e.g. with an audio generator which would not realy need one: You are of course aware of that a termination put to the output reduces the signal level by half (on a 50 Ohm output, on higher output impedances of course even more reduction) as it acts also as an attenuator in conjunction with the source impedance. So if a certain noise reduction is achieved and the 'good' signal is also reduced by the same amount or even more than there is no improvment finally. Only an increase in signal to noise ratio would give a benefit.
And by the way, I think you mentioned that you've got a second PSU. Was it from Owon directly or from where you purchased it and did you have to give the old one back?
And the last thing for now: Checked the web for other DSOs just to learn more about and learned, that Rohde & Schwarz untill August I think have an offer standing that they give 40% discount on any DSO provided you trade in your old one. So get one for e.g. 10.000$, give them your Owon and just pay 6.000$. It's just a 'bit' too much for me but would be actually not such a bad deal. And they have very fine machines.
Good luck
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A little detail by which you can see the struggle of Owons engineers is how the Main PCB is screwed to the frame (so in my model). The hexagonal spacer bolt between frame and input side of the main PCB is a plastic type.
This detail have totally different history from year 2011.
Also in this time we did not have at all this level of "noisy GND" sad case what happend after some peoples in Owon, who did not have enough experience and knowledge, start doing modifications to power supply, adapter board and other things where we can see local switch mode sub power supplies/regulators.
In this time they have forget all rules how to design SMPS and also how to isolate them for avoid common mode noise distribution to all around.
Also in year 2011 internal metal base, aka - Z-plate was polluted but not at all like after these sad modifications.
After this GND noise case totally blow up it was total catastroph and also I did hundreds of hours in lab for investigate this year 2012/2013 new show what Owon schoolboy "designer" arrange to us.
If thinking is that less experienced and educated people get work for design PSU's because of course simple PSU is easy, every schoolboy can "design" SMPS - or something like this thinking. I can tell that just this is perhaps one of most difficult part to desingn and even experienced engineers do lot of shit in this area. But if really know what to do it is "easy".
Afterward modification Owon to "clean" is impossible. It is totally impossible without kick out all exept main board. But still lot of can do. After then it just - what is accaptable and how much is wise to do. If really use lot of hours, investigations, lot of knowledge and experience - it can do quite clean but not perfect. But it can also say that when go to some amount less noise then we have lot of brands what also need "repair" today.
Owon is spread spectrum RF transmitter. (Owon is not alone but this radiating level is terrible if it is this worst version and even manufacture lot may affect due to change of components. Components quality may also vary. One manufacturer 10uf inductor may be totally different as other same looking with same main specs but perhaps very different more detailed specs and result in SMPS circuit may be totally different. Same with diodes, capacitors etc. This may also explain why same looking but different lot may have different noise situation.
But here something about this plastic pillar what was my main reason for answer.
CH1 come noisy after they change CH1/2 front end area lay out / circuit totally. After then this metal pillar connect this some amount polluted Z-Plate to very sensitive GND area inside CH1 circuit. Owon did these and end users get these. After short time problem was solved by Owon and they tell that solution is change one metal pillar to plastic pillar for stop this noise road from Z-plate to front end circuit.
Before this it was very different.
Back to today problem. There is so many noise sources that making it clean is least difficult.
After shut off 6-7 most bad SMPS noise, then under these can see other noises. These separate noises hide each others, so running scope and inspect noise and what part these are generated need trivial trick. Oscilloscope what use for analyze need two channels. Other channel is noise chaos pick up and other channel can synch to different sources. With this method can easy pick up and separate every different noise souce produced fraction. Even Owon itself can use for separate these noise fractions so that these can investigate on the Owon screen. But there need walk over some traps with working methods.
Warning! main PSU prmary SMPS control IC, as other also have told, leaks its fuel - smoke - out very easy. One wrong touch with probe (no need shortcirc) and buff.
After most bad noise fractions are reduced then come data/power share to front panel(s) dependent of version, there come TFT panel itself, there come this terible TFT databus from main borst and thru adapter board to TFT cable. These also are related to version. Some older versions have example display control circuit in totally different place if compare more new versions. (old version have also flat cable from controller to optional VGA output. This time databus to TFT was physically different and afaik less noisy. (now this databus is like mugpie and impedances vary around bus and whole bus radiate around but these frequencies are not very high.
After "noisy GND" catastroph happen I (and some others also) try do some analyzing and help work directly to Owon but... result was bad. They did not believe nearly any recommendations for fast change it better and also handle warranty things for unhappy end-users so that this case do not destroy Owon. I will not show these investigations and final decisions and recommendation for circuits due to some kind of NDA. After then I stop and I'm partially satisfied it is now better than in worst times. many peoples can use it without problems and it have some advantages and disadvantages. I can not work for solve some problems and then after I'm ready I can see peoples have shutted of they eyes and ears. So, they get what they order themselves. I have loosed tens-hundreds of intensive lab work for this without get anything, so just - hands up. It more nice to help and support peoles who listen. I can not do any miracles but I have still "silent knowledge" things after over 50year hobby and after over 30 year active work...
Here link to this some old (and obsolete) "help paper" for this CH1 noise case when some end users do this repair (change this pillar to nylon pillar) and because many users are entry level some need help.
http://www.box.com/s/pvg1dqtdonx192p4os0m (http://www.box.com/s/pvg1dqtdonx192p4os0m)
Btw, who can count all Owon SDS HW versions...and combinations even if talk about same model... how many? I have not any idea anymore. 2011 and some amount 2012 I know nearly sure but today, impossible to know.
Btw, whole all time what I have sold some Owons, end user warranty time problem/failures around 2%.
Some (name hided) brand was over 10% end user side and for me over 40% (difference is because I do 72hour burn in and test for every equipment what I sell exept for Siglent 48h due to building quality and factory better Q.C. in product line. But still these all Chinese factories Q.C. leaks.
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Hi Sarasir,
The new style PSU I got came directly from Owon. They wouldn't give it to me for free, so I purchased it for US 50. In addition, since they only accept bank transfer for payment, I also had to pay fees for the transaction. If I remember right the fees were around US 40. So my old PSU wasn't part of the transaction in any way. However, later on other members got new style PSUs from their dealers after complaining about the GND noise problem. In those instances I think they only had to pay for shipping and didn't have to return their old PSUs.
In any case, I'm currently using my original PSU because after my mods it performs a little better noise wise than the new style PSU that I bought from Owon. Of course, I didn't know it would turn out that way, I didn't do any mods on my original PSU until after I received the new style one. I was afraid I'd smoke it and be without a DSO and that maybe my 3 year warranty would also be void.
By the way, on the new style PSU, the PCB's ground plane, I call it GND-C on my schematic, is directly connected to the chassis (Z-plate) through the PSU's mounting posts. On the old PSU, like yours, GND-C first goes through the ribbon cable before being connected to the Z-plate via the adapter board's mounting posts.
I get what you mean about a 50 ohm termination reducing the signal level of you audio generator. What I don't understand, probably because I don't do much audio work, is why is it necessary to connect the scope to the audio generator via a coax. I'm just not familiar with the application(s) where that is needed or more convenient.
Good luck with the continuing de-noising saga. I think you'll eventually clean up all the switchers. Are you going to do something about the TFT as well?
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Hi TomC,
it's good to know that they sell spare parts directly because you never know what will happen during tinkering around and it's also good practice once you've invested such a long time to make that thing usable to have backup parts in the shelf.
A common audio - and not just audio - setup is e.g. when checking/designing a filter or tone control that you connect the generator in parallel to scope CH I and to the input of the DUT, and to connect the output of the DUT to scope CH II. Then by sweeping the generator through you can see easily the frequency- and phase characteristics of your DUT. And you wouldn't use a probe to monitor the output of the generator, just a direct connection is what you need. It does not even need to be a BNC cable, any shielded one will do - provided your scope is clean!.
You know I already have concepts, pictures and ideas in the back of my head for after I'm done with the switchers. I guess there will be more noise comming up as rf-loop says. The display, of course is already on the list. But step by step.
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Hi rf-loop,
thanks a lot, also for the paper! I will get to it soon.
It was very interesting, almost exciting to read your last post. Now we know a lot more about the history and current situation of the 'Owons'. It's a pity that they cannot open up to serious and advanced users and engineers who spend lots of time to make things good and also to help them. But beeing in this business for almost 50 years I know all kinds of 'blah-blah people' and especially in this business you meet quite a variety. (But I have to add that after I was working with companies like Rohde & Schwarz and Tektronix for many years, there you encounter many wonderfull and highly qualified people. Otherwise they could not keep up with their high standarts.)
And to the nylon spacer, even if I didn't know the history but the reason why it's put in is as I thought: To reduce transferred noise fom the Z-plane to the input BNCs.
And to the trick on how to hunt the other noise with a 2 channel scope, I already did that a bit because I have seen already the hidden noise behind that I could not trigger to by just 'sensing' the little switchers around with a short wire loop or pig tail.
It's always wonderfull to get verification from other people that you are on the right way.
And to your last Btw I want to say that a scope is a long term investment and you never know what challenge or project will come up next.
It could be that suddenly you need a certain feature - like high input sensitivity - you never needed before. Only then you know or usually will find out whether your equippment is good enough or not. As I'm quite experienced using scopes I did a basic over-all test before - but how many hobbyists are able to do that on their first scope - they are still studying. Or a small company needs a scope to do a certain test in production where non of the inherent problems appears.
In short, you can not say right after purchase if you will be entirely happy with a scope or a car or whatever highly sophisticated thing you bought. Most of the time and for most people it will take years to find out all pros and cons.
Btw, do you have a schematic of the input circuitry of the 9302 and could you pass it on to me? I guess I might need it after beeing through with the switchers. I know I could retrace the PCB but you know, it will take many days rather weeks to do that.
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Hi TomC,
...and I would like to ask you to think about this and tell me what comes up:
(scope on battery power)
Let's take it to an extreme and imagine that we would put the whole scope into a tight and close metal box. Then, do you think that there would be any noise on the metal box to be measured?
I would say no! (The cage of Faraday - nothing goes in and nothing goes out)
Then lets drill a hole into the box just as big as necessary for one input BNC and let's solder the BNC sleeve all around to the metal of the box. Do you think that there is noise on the BNC?
I would say no! (Because we cut the return path of the noise emission by means of the box.)
Then lets do a bigger cut-out for to be able to see the screen but cover it with a transparent and conducting mesh.
And in addition lets drill smalle holes for shafts and extensions either plastik or even better metal ones all grounded by springs so we can operate the buttons and knobs.
What would you think? Noise or no noise on the BNC?
Again I would say No noise!
And my conclusion would be that we just need to find a good compromise between the non shielded and the totaly shielded Owon scope. To minimize shielding to excatly the parts which needs it. As a start e.g. we do certainly not need to shield the handle of the Owon you know.
Looking forward what you say....
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Hi Sarasir,
Both Carrington and lemon tried painting the inside of the Owon's cabinet with a conductive coating to achieve a Faraday cage effect. However, they both later on decided to take it off. Primarily, because there was more visible GND noise with the coating than without it. Personally, I thought it was a good idea to shield the cabinet that way, primarily because it would make the scope a little more immune to outside interference. But as I see it, the problem inside the scope was different, I believe the radiated emissions from the switchers were bouncing off the coating and landing on places that were not being affected originally, and this resulted in more visible GND noise. I think if you try something like this the results will be different since you are shielding each switcher individually.
On the thing about the test setup with the scope and DUT in parallel. If I understand correctly this is designed to minimize phase delays introduced by a scope probe so you can accurately compare the phase at the DUT's input and output. But if that's right, wouldn't using the same type of probe at both the input and the output accomplish the same thing? Without thinking about it too much, it seems to me that although there would be phase delays, they would be basically equal, and you could still make valid comparisons. I'm probably missing something!
At one time I wanted to use transparent shielding on the screen, but as I searched around for a source, I couldn't find small pieces at a reasonable price. So I sort of gave up on that idea. Maybe you have better luck.
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Hi TomC,
coating does not work of course. I would never have tried this. You know it's not just the volume resistivity (reziprocal: specific conductance) but also the problem of how to connect it properly. The BNCs would be the correct point and it would need some matall foil and clamps on the BNCs and what else... You use coating e.g. to avoid or keep out statics or it would help in audio shielding but very little for HF. Why do you think HF shields in professional machines are anodized with silver. Remember the skin effect!
Of course you could also work with probes but to patch the generators output directly to the scope is the easiest way. And don't forget the trigger. Why do you think all professional generators have an extra trigger output? It's because then connecting the trigger out to the external trigger in of the scope you are free to change the output to whatever level you need without having to readjust the trigger. They stay always in perfect sync. Remember, if you change the level of a sine wave the trigger point will move in time if you had adjusted it off zero what often is necessary for several reasons. Or it would stop triggering if you turn down the output of the generator below the trigger level chosen. So the professional way is to trigger externally in our example setup. Of course you could also do the trigger connection with a probe, but, come on.... should I continue?
And, phase delays through cables are not a basic problem in audio equippment, only when the circuit starts oscillating erratically usual at high frequencies.
Probes have a resistive and a capacitive attenuator that compensates for phase delay - ideally. In practise there might be a little present at the upper bandwidth limit but if that's much you should calibrate your probe or it's junk.
My setup was only hypothetical for to get a better imagination of the circumstances and a clear picture in mind how these probs could be solved. And I do not think that I will need a mesh eventually.
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Hi Sarasir,
The idea for the coating, as I remember, came from the way some other manufacturer finishes the inside of the cabinet of their scopes, I think it may have been a Tek DSO. Not sure what the material was, but for the DIY I think Carrington used copper based and lemon nickel based. Didn't know about the use of anodized silver on shields, but as you said, it would certainly improve the conductivity at high frequencies right where is needed (the skin), learn something new every day...
Like I said in my post, I wasn't thinking too much when I wrote about phase delays. So of course I agree that this shouldn't matter much for audio work, propagation time wouldn't exceed more than a few ns at worst. I'm more used to using probes, hardly ever take them off the scope, so I was just curios why they were not the preferred connection method in this setup.
As for the hypothetical setup of your previous post (the faraday cage with holes connected to the BNC), I still think it's an extension of the chassis, so any common mode currents flowing through the chassis will also be present throughout the part of it that is used as a faraday cage. Of course, currents tend to follow the path of least resistance, so the same intensity is not felt in every corner, but I believe there will be electrons in motion everywhere on this surface.
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About something.
Faraday box is not easy for higher frequencies in this kind of situation. If build whole Owon including its mechanic new and so on... situation is very different.
Inside Owon appears frequencies over 200-300MHz (fast parts of rising edges in some SMPS)
It is good to imagine that 50mm long and 10mm diameter copper rod is "50 ohm" for around 350MHz sinewave. You can use it as 50ohm termination and your transmitter output do not short circuit at all but it just see around 50ohm normal load. With 3GHz or more it is much more fun.
If you make "faraday box". between every point of box is also reactance. Oh well, then think that there do not flow currents over this plate. It is true for DC if you have faraday box what is connected just using exacly one point. But more high freq we go and then inside box shielded machine have "lot of" capacitive connections to this faraday box different positions.
This very simple thinking may continue to deeper and deeper and it can easy think that doing some kind of conductive painting inside Owon box do not help in practice just nothing and there is lot of reasons. Or take just 1mm copper plate. say example 10cmx10cm.
What is inductance between its opposite corners. Try calculate its reactance for example 500MHz.
I can ask, is it easy to make faraday box in practice so that you still have GND connection to some point(s) and pot of capacitive (and also inductive) connections to this box infinite points. And between any point there is inductance and capacitance. (it is good to remember that with these situations in owon example this Z-plate is not "one GND". (You can measure different RF between every point of this plate. And also from separate PCB's separate points of GND's. Whole construction is "mugpie".
Yes fraday box for LF is more easy and faraday where is not connections from inside to outside.
And then, there is magnetic fields...
But small local SMPS noise can attenuate more easy to acceptable level (what is acceptable level?) if do these locally with hard work with many mechanical/electric modifications.
Do not produce noise. It is much better than make noise and then try isolate/attenuate noise from travel to wrong place.
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rf-loop,
my idea with the cage of faraday was only for to develop further imagination and feeling for what to do. You know, getting a clear picture of what are the extremes.
I can underline all what you say. Of course there is reactance in the cage everywhere but I think with very low Q and btw. what's about the eddy currents?
My way is of course according to your proposal to remove and shield all switchers in small tin boxes to kill the noise right there where its originated, and I'm almost done with that. Only the -7.4V switcher on the main psu is still waiting but for now I have this connected through long wires to the scope and of course additional filter components.
My experience so far is that the moment I close a tin box with a running switcher inside the measurable spikes outside go down to almost zero. But I also have used additional capacitors and coils to filter down the spikes on the in- and outputs.
(it is good to remember that with these situations in owon example this Z-plate is not "one GND". (You can measure different RF between every point of this plate. And also from separate PCB's separate points of GND's. Whole construction is "mugpie".
Yes, I discovered that as well - see earlier posts.
TomC,
coating is of course a practical way to further improve shielding as done in some low cost Tek machines. But not to be enough here where very strong emission is the problem. Here you would have to at least anodize the plastik. E.g. the inside of the plastic covers of the Tek P6046 differential probe is gold plated.
Please once more think about if you want and tell me your opinion of how does the return path of the noise that is present on the BNC input sleeves look like.
(That is what's going around in my head in anticipation of what to do against the remaining noise once the switcher noise has been eliminated and the cage of Faraday model was just one try or approach to get the whole picture.)
If there is current comming out somwhere there must be a path through which the loop closes, no doubt (I think that it must take place through the electrical field that's build up towards the evironment by all other parts of the Owon except the BNCs themselves once they are connected to another machine like a generator.)
...and I found the emty 5 literes tin can I have kept after having used up the Greek olive oil that was inside. Unfortunately the Owon is a little bit too high to fit in right away. But - I know myself - as soon as I have the Owon working again I will bend and torture this poor can to get the Owon inside.
Then we will see.....
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Sarasir,
There is no single return path in my mind, and I doubt that the BNC sleeves themselves are at the center of any particular current flow path. But there are currents flowing through the Z-plate and all the ground planes connected to it. These elements are in theory a common path, but to individual current loops they are just part of the roadway that comprises the loop. For DC and low frequency loops I view these elements as part of a wider highway with a fairly even traffic distribution that accommodates the needs of multiple loops. However, at higher frequencies, because of impedance variations due to interconnections and/or structural characteristics, the traffic distribution is no longer even. As a result the electron traffic will be more intense in the areas offering a lower impedance path, and of course less intense in those areas with a higher impedance. Nevertheless, every part of this highway will be affected by this traffic to one degree or another. The BNC sleeves are connected to it, so they are part of the highway, although as I said, I doubt that they are at the center of any particular path.
Of course, most of the traffic is comprised of differential currents used to power the various scope circuits. But some of this traffic, particularly HF traffic, are common mode currents that originated with the switchers due to stray capacitances, inductances, or radiation. Although unintended, these are also current loops, and are also what we call GND noise. Had these currents been confined within the boundaries of the switchers that originated them, by proper design, circuit layout, and/or shielding (like rf-loop says, don't cause noise), they wouldn't be an issue. As it stands, this didn't happen originally, and although it has been alleviated on current production, it hasn't been eliminated. There is probably little incentive to do so since competing products suffer from similar ailments of various degrees.
Now, however, I think that what you are doing can potentially confine the fast rising currents associated with each switcher to their respective boundaries. Basically, it seems to me that this is a major redesign. With the switchers isolated any common mode currents attempting to escape via the associated input or output wires can be effectively filtered with a common mode choke. Along with some additional differential mode filtering, I think these switchers can potentially be as clean as traditional linear circuits. With that accomplished the HF common mode currents on the Z-plate and ground planes should be virtually gone. At that point, in my view, the only impediment to a totally GND noise free scope will be the TFT. I'm not sure that a Faraday cage that doesn't include the screen can eradicate the effect of this noise source. However, from what I've experienced, this noise source is mostly near field, and usually can be easily avoided by keeping the probe cables away from it. So if it's not too bothersome, why mess wit it!
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Hi TomC,
a fine and profound overview of the situation, thanks a lot!
Just one step further I would like to push you if you don't mind:
(Not considering any local details like switchers or display. Just let's assume that the only thing we know is that there is lots of noise and a common DC ground plane everything connects to (would not be even necessary but it helps) with all that 'hasty and speedy social life of countless electrons and many of them quite ambitious in there urge to escape to other realms', like you described in a more scientific way.)
And this then would be my question:
May we not choose any point of this complex system and say, here we would like to have a point of zero potential towards the outside world and what would we have to do to make that a reality?
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Hi Sarasir,
I don't think you can make it absolutely zero potential under any circumstances, but you can come close by providing a better earth ground than the one it already has. If we are going to go to the edge of the deep end, I think we would be thinking of a massive, with plenty of conductive surface to cover high frequencies, rod driven deep into the ground. Something large enough will probably exhibit very little deviation from zero potential even if struck directly by lightning. I don't think this is the solution you are hoping for, but what else could you do without straying into science fiction?
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Hi TomC,
brute force you meen! Unfortunately a bit too much to realize and live with in this case I would say...
I thought it should be possible to establish a point of zero by closing the loop(s).
That meens to bring back all the electrons which want to escape exactly to the point that you want to be 'zero'. That means in practice to catch all 'run-away' electrons with a shield and connect that shielt to that point. This point then should be in a way satisfied and free of potential.
Through our correspondence every time the picture in my head gets a bit more in focus.
The whole thing acts like a balance I think. The more electrones are escaping (and also returning) on one side the more electrones will be pushed out and pulled in on the other side - the BNCs - because the whole system needs equilibrium.
I'm almost at a point where I can see the whole thing pretty clean without even removing the switchers but then the shield must be very good, and perhaps even more important the connection of the shield to the point of zero.
Have my 'externalized' power supply(s) tested and ready now. Tomorrow I will connect it with the main circuit through about 80cm long wires I prepared today.
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!Correction to my drawings!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
When checking through my papers today I found a failure in my drawings of the Power Scheme (Original and Modified) and of the +5.6V switcher:
The +5.6V switcher is not enabled by the +3.3V switcher's output! It's Enable input is connected to the +8.4V of the main PSU (which supplies also it's input)!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!Correction to my drawings!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
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Hi Sarasir,
I also agree with the concept of confining/closing the loops within a controllable environment. Which is I what I think you are doing with your external power source. There is one element that I don't see in your drawings that I believe would help considerably getting the noose even tighter, common mode chokes. To me these are like miracle devices, because the inductance is mostly apparent in the presence of common mode currents, but practically disappears from the point of view of differential mode currents. I would consider using these on the wires connecting the external power source to the Owon. You could even try ferrites on the wire bundle, which are roughly equivalent to hardwired common mode chokes, and if they make a difference then go the hardwired route.
Leaving the switchers in situs, in my opinion, would leave few and probably insufficient options to control the environment to the extent that you are striving for, because to a large extent you have to live with what Owon has already done. So the possibilities for changing the layout and adding components are severely limited.
Anyway, I wish you the best of luck in your upcoming experiment, and I'll be waiting to hear the details of how it turned out! :-+
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Hi TomC,
to exernalize all switchers is not directly part of closing the big loop(s) to the input BNCs I may remark. It just will make that easier by taking away the contribution of these switchers to the big loop, therefor keeping down the shielding efford. (of course if you put a switcher into a tin box it's also closing a loop, but just locally!).
And to the cores: If you look at my pics again you might see a big core near the main PSU through which the colered wires - the ones from the PSU to the scope - go. Bu that is preliminary still.
There are also draw backs using cores. (And btw. my drawings also are just preliminary and I have not drawn common mode cores yet because I'm not sure yet if, how and where to put them exactly)
You may easily use a core on a two wire connection (signal and return path like your probes) but if you have a bunch of wires with different currents and different noise occurencies all referred to a common ground wire you might have to consider that a core acts also as a transformer (not to speak about core material and saturation effects yet.). That meens that you might couple spikes from one voltage line to another and vice versa. All might be cancelled out again as long as the sum of all electrones goes back through the common ground wire that also goes through the core, but first tests I made showed that in practice it is not exactly like that.
So better concentrate on that later, but now as you mentioned it there is already a picture getting sharper and we will certainly find out more about.
Yes, of course and I repeat what you have said in other words, once having them out they will go back only after having them all caged in a propper tin box.
Well, and thanks for the good spirit. Soon we will know a bit more.
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Hi Sarasir,
Yes, I think you got it pretty well covered for now, and will know more once you test it. I attached a partial schematic of the SDS input that I think came from tinhead some time ago. Don't know if you had already seen it or if it also applies to the 9302. But I remember you asked rf-loop for something like that and I just ran into it while rummaging through my SDS7102 folders. Once again, good luck!
Edit:
The PDF has better image quality.
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I recently decided to purchase an inexpensive pair (under US 50) of 200MHz probes to take advantage of my SDS7102's surplus bandwidth. Browsing through eBay, Amazon, and others I found a number of choices in this price range. From a pair of Neewer EM#01 for US 15.60 (free shipping) to a pair Of Owon T5200 from a website in Austria for Euro 29 (+shipping & other fees). I finally decided to order a pair of Li Hua P6200 from a US eBay seller for US 33.90 (free shipping). These probes are advertised as high quality suitable for HP & Tektronix, and feature lower input capacitance than the other contenders in this price range.
Once the shipment arrived I proceeded to test their bandwidth by scoping different signal sources and comparing the results with some of the other probes I own. The attachments show some of the comparison results. In all of these captures CH2 (yellow trace) is connected to the Li Hua P6200, while CH1 (red trace) is connected to either a Hantek PP-80 (60MHz) or to an Owon T5100 (100MHZ). The last 3 images show the specs for these probes as they appear in their respective user manuals. All probes were carefully compensated prior to these tests.
#1a through #1b - Here I compare the response of the 60MHz Hantek prove (H) and the 200MHz Li Hua prove (L) at different RF generator settings. The amplitude of the signals is very similar, so additional testing is needed to find out whether the Hantek probe is quite a bit better than 60MHz or if the Li Hua is no better than 60MHz.
#2a through #2b - Here I compare the response of the 100MHz Owon probe (O) and the 200MHz Li Hua prove (L) at different RF generator settings. At 50MHz the amplitude of the signals is very similar, but after passing the 60MHz mark the amplitude of the signal displayed by the Li Hua probe is quite a bit less than the amplitude displayed by the Owon probe.
I repeated this test using a Tektronix P6105 (100MHz) and obtained almost identical results. I also tested the second Li Hua probe to rule out the possibility of a single defective probe. The results were identical, so at this point there is little doubt in my mind that my new 200MHz probes are really misrepresented 60MHz probes.
#3a through #3b - Here I compare the probes using a fast rise signal (< 4ns). The probes are connected to the scope calibrator's output via a T and two BNC to probe tip adapters. The Owon probe clearly outperforms the Li Hua with a 2ns advantage. The Hantek and Li Hua probes have almost identical rise time, with the Hantek winning by a fraction of a ns. It seems that the Li Hua probe barely qualifies as a 60MHz probe.
I explained to the eBay seller, AST Labs, that although these probes were misrepresented, I didn't want to return them because I planned to post my findings here and needed them as proof of my claims. The seller responded quickly and indicated that they were unaware of this problem and would investigate immediately. They also offered me a full refund without requiring the return of the probes.
There is a number of possible reasons why these probes don't perform as labeled and all I can do is speculate. The probes in my possession look and feel genuine, and the label looks identical to the one in the attached image. So I doubt that they are counterfeit or fake. It's possible that these are really P6060 probes that got inadvertently mislabeled at the factory. On the other hand, it's also possible that someone is trying to make a quick buck by relabeling less expensive P6060's and hoping no one will be able to tell the difference. However, I have no reason to believe or suspect that the seller, AST Labs, is involved in any type of fraudulent behavior. They have a stellar reputation with 100% positive feedback and handled this case quickly and without hesitation to my satisfaction.
I'm still interested in a pair of inexpensive 200MHz probes, but at least for now, decided to stay away from Li Hua for obvious reasons. So I ordered a pair of Hantek PP-200 probes from an Amazon seller for US 31.99 (free shipping). I'll be reporting my findings as soon as I get them.
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Hi TomC ++,
have the Owon working again but there is still some tweaking to do. There is ringing on the wires, and absolutely awkward, there is new noise in my appartement. Heavy noise I've never seen before. I guess that somebody around me must have purchased a new TV set or so (Soccer Worldcup just started). My whole place is polluted with around 2MHz noise comming through the mains supply but also through the air. Toutching the input of my Tek 475A the noise level is even higher then the 230V/50Hz mains voltage displayed. The Owon is of course not switched on and the new noise shows like packets of HF synchronous to the 50Hz so it's not a DC/DC converter but rather a AC/DC type whatever. Have no Idea. Looks a bit like a Thyristor or TRIAC dimmer but with continous oscillation over about have of the sine period starting allways around zero transition.
I called the German Bundesnetzagentur (Federal Network Agency) who is controlling and enforcing all respective regulations but have to call again on Monday for to speak to a technician.
What else to say for now. I don't know yet what I will do. Building myself a big cage of Faraday or to wallpaper my workshop with aluminum foil...
Perhaps the Bundesnetzagentur will come and do some measurements and tell my neighbours to bring back their new TV set or throw away their broken microwave oven. It's just crazy, but time will tell...
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Hi Sarasir,
Good to hear from you!
I was wondering what happened! I'm glad that the Owon is working again! :-+
Over here the FCC deals with situations like that, once in a while a HAM radio operator causes trouble for me, but it never lasts long enough for me to report it.
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....and before checked again and it has disappeared - discovered it two days ago and yesterday it was still present. Now it's again just 50Hz sine wave without any HF noise just the usual abberations. Strange.... hope it doesn't come again.
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hi
i live in Iran and i want buy scope but i can pay 360-400 Euro .(or little more price)
i want buy GDS-1072-AU or SDS7102E and i need your help .
when marmad say SDS7102 better i see the price a little much for me so i see marmad in this forum to tell us to buy Rigol DS2072 / DS2000 series DSO , so i am amazed to buy which of them.
i need 70 or 100MGH dig scope , if you have another choose please say me.
so GDS or Owon or Rigol ? can tell me more data please
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Hi mohandes,
I own an Owon SDS7102, for the price, even with a few shortcomings, I think it's a good value and you get 100MHz, is usable to about 200MHz, and has a large LCD. On the other hand, the Rigol DS2072, is a better scope, with a built in upgrade path when you need it, but it's only 70MHz, at least initially, and you have to pay almost twice as much. So it's a matter of what you can afford and what you foresee you'll need in the future. At least that's my opinion. Good luck! :)
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thanks
what is your idea about GDS1072AU ?
what is diff between Owon SDS7102 and Owon SDS7102E ??
and DS2072A ,DS2072A-S ??
i need good scope , but i dont know which is the best !!
1 GSa/s for sampling is good for me too and between 60 to 100MHZ, i need your data for best scope that you have.
excuse for my English
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Hi mohandes,
Here are a couple links with more information on the GDS1072AU and DS2072A-S. From what I see the A-S includes a built in signal generator:
https://www.eevblog.com/forum/testgear/new-instek-scope-gds-1072a-u/ (https://www.eevblog.com/forum/testgear/new-instek-scope-gds-1072a-u/)
https://www.eevblog.com/forum/testgear/any-rigol-ds2072a-s-user/ (https://www.eevblog.com/forum/testgear/any-rigol-ds2072a-s-user/)
The SDS7102s have an alpha designator that tells you some of the features limitations. Mine is an SDS7102V, which has a VGA interface for direct connection to a computer monitor. It also has a battery option and deep memory is standard. From what I can see the SDS7102E is a less expensive model that doesn't have the VGA or battery option, and the deep memory is an extra cost option.
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Hi mohandes,
Here are a couple links with more information on the GDS1072AU and DS2072A-S. From what I see the A-S includes a built in signal generator:
https://www.eevblog.com/forum/testgear/new-instek-scope-gds-1072a-u/ (https://www.eevblog.com/forum/testgear/new-instek-scope-gds-1072a-u/)
https://www.eevblog.com/forum/testgear/any-rigol-ds2072a-s-user/ (https://www.eevblog.com/forum/testgear/any-rigol-ds2072a-s-user/)
The SDS7102s have an alpha designator that tells you some of the features limitations. Mine is an SDS7102V, which has a VGA interface for direct connection to a computer monitor. It also has a battery option and deep memory is standard. From what I can see the SDS7102E is a less expensive model that doesn't have the VGA or battery option, and the deep memory is an extra cost option.
thanks
can you put here for me like of your scope ?
Mr marmad said DS2072 better than SDS7102 , do you agree whit him ?
your scope have good in all frequency and bandwidth ?
regards
se this topic please
https://www.eevblog.com/forum/testgear/which-model-of-scope/ (https://www.eevblog.com/forum/testgear/which-model-of-scope/)
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In many ways it is, but it all depends on what do you mean by better? For example: How much are you willing to spend? And what features are important to you? There is no black and white better or worst! :)
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In many ways it is, but it all depends on what do you mean by better? For example: How much are you willing to spend? And what features are important to you? There is no black and white better or worst! :)
for same pay ( i can pay 800$ to 850$) i want buy the best , i say need 70 to 100MHZ and 1 to 2Gs for sampling.
and i want know which is better for same cost ?
thanks again
i read datasheet of SDS2000(SDS2072 ) and DS2000A(DS2072 ) , and i think SDS better .
SDS7102 good too for me .
and i really Helpless .
regards
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Hi TomC,
it's not so easy as I thought. The long wires bring other problems I have not thought so much about yet. E.g. the + 1.9 supply must be very stiff. I think it is for the CPU/controller and has to supply around 0.8A. So far, with additional capacitors on the main PCB it works but after a while the Owon hangs up in a way and there is lots of spikes on the scope side of the supply wires I can see now coming from the main PCB not from the supply. Next I will stiffen the + 3.3 and try to get rid of the spikes from the main PSU or better to say first to find out where they are comming from exactly.
I should have known as on a PC main board the processor supply is always close to the processor. Of course a PC CPU draws more power but in a way the basic rules are the same I would say.
Another thought is that this hanging up problem might be a defective chip or soldering because it goes along with the main PCB heating up a bit. Somtimes it goes away by itself. and comes back after a while. Turning the power off and on the Owon works again, so it's not so much a heat problem. Have to check that again watching the average time it take until hang up if it's cold and if it's already warmed up.
And have trouble with my teeth. Got 4 implants recently and yesterdy 2 had to be taken out again. Running to the dentist about every third day since weeks takes time and I feel a bit stressed. But what can you do, shit happens....
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for same pay ( i can pay 800$ to 850$) i want buy the best , i say need 70 to 100MHZ and 1 to 2Gs for sampling.
and i want know which is better for same cost ?
thanks again
i read datasheet of SDS2000(SDS2072 ) and DS2000A(DS2072 ) , and i think SDS better .
SDS7102 good too for me .
and i really Helpless .
regards
In my opinion, the Rigol 2072 and the Siglent 2072 are pretty much in the same class. It boils down to the specific features that you value the most. The Siglent seems to have a richer feature set, but it's newer and has a better chance of having more unresolved bugs. The Rigol has been around a while longer, and from what I hear many bugs have been already resolved. Also, there are a number of users that have managed to hack it and unlock extra cost options for free, if you are interested in that, Btw, personally I'm not. The Owon SDS7102 can't touch some of the features available in the Rigol and Siglent, but is cheaper, and it has 100MHz+ bandwidth without hacking, so if you are happy with the feature limitations is a good buy. That's about the best I can do to help you decide, but ultimately is up to you. I think you'll probably be happy with any one of these scopes! :)
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Hi TomC,
it's not so easy as I thought. The long wires bring other problems I have not thought so much about yet. E.g. the + 1.9 supply must be very stiff. I think it is for the CPU/controller and has to supply around 0.8A. So far, with additional capacitors on the main PCB it works but after a while the Owon hangs up in a way and there is lots of spikes on the scope side of the supply wires I can see now coming from the main PCB not from the supply. Next I will stiffen the + 3.3 and try to get rid of the spikes from the main PSU or better to say first to find out where they are comming from exactly.
I should have known as on a PC main board the processor supply is always close to the processor. Of course a PC CPU draws more power but in a way the basic rules are the same I would say.
Another thought is that this hanging up problem might be a defective chip or soldering because it goes along with the main PCB heating up a bit. Somtimes it goes away by itself. and comes back after a while. Turning the power off and on the Owon works again, so it's not so much a heat problem. Have to check that again watching the average time it take until hang up if it's cold and if it's already warmed up.
And have trouble with my teeth. Got 4 implants recently and yesterdy 2 had to be taken out again. Running to the dentist about every third day since weeks takes time and I feel a bit stressed. But what can you do, shit happens....
Wow, seems like you have your hands full! But you have done many modifications at once, so some hiccups are to be expected! Hard to tell if the hang-ups are related, but noise in the processor supply would definitely be a suspect in my opinion.
As far as the main PSU, I found most of the noise was coming from the -7.6V switcher, particularly L2. There also was a little bit of noise coming from the 8.4V switcher, particularly from TR1 (transformer). I don't know how you plan to handle that, I replaced L2 with a toroid and put a belly strap on TR1. That got rid of most of the noise in my case.
Hope everything settles down and improves with your dental treatment! I'm lucky enough to be missing only two back teeth at my age. But I'm a dental hygiene fanatic that brushes, flosses, and water picks three times a day and never snacks between meals. Maybe that has something to do with it, or maybe is just good luck.
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thank Tom
my friend have 500$ , and i tell him SD7102 is best ? i say right to him :-// ???
regards
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If it was me, I'd still choose the SDS7102 if I only had $500 to spend! :)
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I have just succesfully flashed firmware v3.8 to my SDS7102V. I'm installing Owon's PC software now.
You can find Rigol DS2072 directly from China on taobao. Price is from 740 USD without shipping. SDS7102 is from ~ 290 USD without shipping.
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I have just succesfully flashed firmware v3.8 to my SDS7102V. I'm installing Owon's PC software now.
You can find Rigol DS2072 directly from China on taobao. Price is from 740 USD without shipping. SDS7102 is from ~ 290 USD without shipping.
thanks
but in this site write 940$ !!!!!!!!!!
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Hi TomC,
built an extension for to be able to work on the main PCB. Without it's also practically impossible to calibrate the input you certainly know as well. I thougt that the hangups might be erratic oscillation in the input circuitry, at least it feels like that because the whole screen fills with distorted high frequency and the machine does not really hang but gets very slow in reacting. And when it goes away it looks like if you are working on an amplifier which oscillates and by bending a wire the self oscillation collapses.
Enlarging the input shielding might be the initial reason. I thought that would give less input capacitance and there was enough space especially on the rear side.
Will see tomorrow, and meanwhile some pics below.
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Sorry Sarasir but I do not understand anything what you have done with analog front end and why.
I have inspected many versions of Owon analog front and I have not finded any reason for modify shieldings etc (exept first version where BNC's was not at all instelled to PCB). Front end is one of best front end in this class if look example its noise level and frequency band. Also Owon input capacitance is originally typically quite low. It was this layout version we measure it by VNA and it was "around" 8pF (under Owon specs). There is not any reason for try get it more low. Tektronix 2465 have 15pF and they really know what they do. Same in old HP, in this case 8pF in 500MHz scope and agen in one Tektronix 500MHz it is 10pF. (nominal +/- something)
In original condition input circuits do not picup any markable amount of internal or external noise around it. Close differential input (50ohm terminator is enough and zero z do not make big difference) and you know it after you measure noise figure and repeat it with open differential input (example using 50ohm terminator without center tab connected) and measure noise figure (not only level). In this case differential input other pole is exactly this part of BNC outer terminal what is just in position where is its inner terminal (connection point). This is reference point and nothing else if think oscilloscope input.
Compare this noise figure with Agilent, Tektronix, or even Rigol better models than 1052.
Now you tell that your input stage oscillate? (really? )
You have changed parasitic components?
Just return all exatly as it was after factory (I mean only front end - but overall nice experimental work :) specially for reduce SMPS generated RF noises) and you have reasonable good front end well comparable with Agilent and Tektronix much more expensive models. In worst case, modifying shielding there may lead even worse result even if it looks like "better" physically with eye. (it is due to fact that where these noise currents flow) (this is not for Owon but sometimes example changing RF field "GND" connection points may lead worse situation because it change noise current road. It is good to imagine that there is not common homogenous GND! Every single point in GND is different where ever it is. DC and low audio is different and 1MHz is quite easy but 1GHz is more difficult and 1THz is just magic.
In Owon - just analog front and also ADC is very good. Other good part is very good quality TFT.
added sidenote:
it looks that your front end version is version what can not fully adjust without separating front panel board and main board. Some version can adjust more easy.
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Sorry for side track a little. Could anyone share the tx file if your SN is one of the SNs below:
SDS71021122xxx, SDS71021127xxx, SDS71021137xxx, SDS71021143xxx, SDS71021149xxx, SDS71021152xxx, SDS71021153xxx, SDS71021203xxx.
I accidently overwritten the tx file on my machine when playing with "launch.exe usbpatch". Apparently, "launch.exe usbpatch" is a dangouse combination. It will download the file named "bundles" to the device with brutal force and without checking its contents. It so happened, one of the patch comes with a "bundles" file for some other HW platform and it had a tx file, and I played with it without knowing.
I have since re-downloaded the correct fw (OS_H6 for SDS7102) using the same "launch.exe usbpatch" option. The machine is working again. But I am unable to recover a same or similar tx file. I have tried recreate a tx file based on those in txs.zip. But, those are not for 7102 or not for the HW version 6 (as in OS-H6). I also tried on screen cal adjustments by activating the switch in the tx file. Many things can be caled, but not all of them. Especially the DC trig level mismatchs a lot.
I understand the cal data in the tx file is probably per machine. What I need is an example tx file (clear text or encrypted) for HW version 6 (SNs are listed above) of sds7102 to work from.
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Hi TomC,
built an extension for to be able to work on the main PCB. Without it's also practically impossible to calibrate the input you certainly know as well. I thougt that the hangups might be erratic oscillation in the input circuitry, at least it feels like that because the whole screen fills with distorted high frequency and the machine does not really hang but gets very slow in reacting. And when it goes away it looks like if you are working on an amplifier which oscillates and by bending a wire the self oscillation collapses.
Enlarging the input shielding might be the initial reason. I thought that would give less input capacitance and there was enough space especially on the rear side.
Will see tomorrow, and meanwhile some pics below.
Hi Sarasir,
It's obvious from the pics that you put a lot of effort on the front end shielding, and the craftsmanship looks excellent! :-+ However, I agree that this may have something to do with the hang-ups. If it was me, I would consider doing what rf-loop suggests and return the shielding configuration back to factory condition, at least as a troubleshooting step. If that successfully corrected the hang-up symptoms, I would concentrate on the other part of the project and get rid of the noise produced by the switchers first. Then, if necessary, I would tackle the front end shielding again.
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Hi rf-loop + TomC,
of course I noticed that the input noise of the Owon is very low and 10 pf input capacitance is also pretty low compared to my old Tek 475A with 20 pF.
I increased the distance to the PCB of the front and back shields by alltogether about 6mm. That should not decrease the input capacitance very much but might give me also the option to replace the ceramic AC coupling C with a decent one but don't know yet if a Tek made I have a few will fit in.
And there is also the thought to add a teflon variable C (also Tek made) by which you are able to calibrate the input capacitance. For this I would need a little headroom for to arrive finally at 10pF again.
But nothing decided yet, just providing options. You know there was space and why not use it.
And to the shield itself. After taking a first look at the input section I noticed that the shields where soldered only at three points to the PCB, an absolutely no go in my opinion.
If you had worked in the Tek lab for 10 years and knew all the machines you also know that circuits like this have to be in a closed shielding cage, no doubt. Nothing goes in and out except the signals that are supposed to.
Of course I could have soldered the original shield all around but with the consequence of not beeing able to open it up again without straining or even killing the PCB, should there be some work to do inside.
This input cage in itself is practically free of differential digital noise and consequently therefore is the reference point for the whole machine. Any noise that is radiated from other points of the machine to the environment will make that point radiating noise as well because the radiation loop has to close as it's true for any transmitter. To minimize or even kill that you 'just' have to catch all radiated noise and bring it back to this reference point internally. Then there will be no more noise potential on the BNCs to be seen anymore from the outside.
Of course as you already pointed out all noise sources (power switchers) should be minimized locally first, but then, what will you do with the noise radiated by the digital circuitry of the main PCB? The only way I can see is to first bring in the cleaned supply currents to the main PCB to a point as near as possible to the input cage for the make sure there is as little as possible voltage drop caused by the digital circuitry noticable to the input cage, and to bring back the radiated noise from the digital circuitry also to the input cage for closing the emission loop(s).
Then, in theory the Owon should be clean.
But I know in practice often you will come across problems you haven't seen before but you know 300 MHz is not too much to handle. Thanks God I havent bought a 1GHz or even higher scope from Owon. Saw a Tek 33GHz scope recently....
Hi TomC,
there is no way to go back to the original state with the shielding. Too much work, too much risk, and to increase the stray capacitances between the input circuit and shield again is easy once I'm able to work on it and to see any results right away. That's why the extension...
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This is the sequel to post #2472:
https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/msg460398/#msg460398 (https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/msg460398/#msg460398)
I recently received the 200MHz Hantek PP-200 probes I ordered from Amazon. To the limit of my RF generator (110MHz), the response of these probes is nearly identical to the 100MHz Owon T5100 probes that came with my SDS7102. This leads me to believe that the PP-200 probes at least qualify as 100MHz probes. I don't have access to the test equipment required to accurately further asses the response of these probes. However, I did conduct a few other experiments.
First I tried a homebrew diode frequency doubler attached to the output of my RF generator. This allowed me to check the response to nearly 200MHz, but with very low level signals (<50mVpp), due to the inherent losses associated with this type of doubling circuit. With one probe at a time connected to the output of the doubler, the T5100 probes produced a larger amplitude signal than the PP-200 probes. However, with a T5100 and a PP-200 probe connected simultaneously to the doubler the signal amplitude was nearly identical. Since the PP-200 probes have a larger input capacitance than the T5100 probes, I believe this effect was due to higher signal loading when the PP-200 probe was connected to the frequency doubler by itself.
Still, this test doesn't give me conclusive evidence of the response of either set of probes, just that their response is similar at up to 200MHz. It could be that the T5100s are really much better than 100MHz probes, or that the PP-200s are just 100MHz probes.
I plan to do some additional experiments, and I'll report any interesting findings that materialize. In the mean time, if anyone has tested the response of the Owon T5100 probes with appropriate equipment, I would very much appreciate it if they share their findings!
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Hi Sarasir,
I get where you are coming from! Keep us posted, I find what you are doing very interesting! :)
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Hi Sarasir,
I get where you are coming from! Keep us posted, I find what you are doing very interesting! :)
+1
Very interesting!
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Yes TomC and rf-loop,
thanks a lot but also have to add that it was you guys here who contributed their knowledge and experience as well on the way to develope a pretty clear picture of the circumstances and possible solutions so far I would say. With the Owon at first I had just lots of nebulous thoughts and started to remember what I had learned the time with Tek. You know in my personal interest I'm just an audio man and yes, also a devoted and experienced trouble shooter but after I've left Tek in fall of 1987 I didn't care so much about RF except that practically in every field nowadays you have to deal with digital components clocked by RF frequencies...
Just let me put it like this, only with the right partners you can reach the highest point!
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Hi guys,
after above doodle doodle - sorry, but you should know I'm really happy to be able to discuss with you here - reality came back. During bringing all supply lines directly to the main PCB the erratic display or hang ups didn't go away at all anymore. And after getting me the datasheet of the A/D converter (MXT2815 supplied by the the +1.9V switcher) and studying it a bit (all in chinese, let Google translate it!) I had to understand that this chip is a bit demanding regarding the power supply. It has a build in power down routine and as far as I understood doesn't like too big filter capacitors on it's supply lines - 100uF says the sheet I understood so far - and I put much more. Didn't get through yesterday but have a certain feeling...
Anyways I'm thinking about getting me a second SDS 9302 as a backup and test rig. That's always good practise.
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Hi Sarasir,
The Google translation is awful, but if I understood right, it says that a 150mV overvoltage or voltage spike in the supply line can damage the chip. If that's correct, this thing is super sensitive. But you would think that extra capacitors would decrease the chance of a spike, so maybe the problem is reversible. Let's hope that's the case anyway! :)
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This is also useful to read
http://www.ti.com/product/adc08d1520 (http://www.ti.com/product/adc08d1520)
Do not ask if it is same or not. ;)
But useful to read.
(note with pin numbers. It is typical that RuiFeng add 2+2 N.C. pins to every corner)
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It sure looks similar, same warning about the 150mV overvoltage!
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Hi TomC + rf-loop,
rearranged the common/ground wires yesterday and it was working again - thanks God! But have to give it a little more voltage later today as there is a voltage drop due to the long wires I have put in between all PSUs and the main PCB. Only 1.85V arrive at the MXT2815. It seems to consume a bit more than what the sheet says 'cause I have tested before with a resistive load and it was precisely 1.9V.
Thanks a lot for the TI link + information. Seems that it's quite similar to the RuiFeng - reading the description briefly at least....
Spikes on the supply lines are quite low now except for both display supplies which are still pretty dirty. Also the display signal lines I have not really looked at yet. Probably shielding and cores right where they leave the main PCB I can see so far.
I should be able to unplug the adapter PCB with the display ribbon alltogether without problem now as no vital function for the main PCB is located there anymore but haven't tried yet (then using the VGA to monitor)
The problem with the display circuitry supply is to keep up with the power up timing what should be no problem at all as it draws not much amps so it just has to be redesigned carefully.
Don't know yet exactly what to do with the backlight supply switcher as it's output capacitor is limited to 10uF max because of the current regulation loop. Replacing the original electrolytic with tantalum and/or ceramic turned out to be not enough and also did not add much inductivity for not to dephase the loop. Probably have to redesign this completely. Perhaps you have found a solution already rf-loop?
rf-loop, have you replaced the ADC once yet and can you buy from RuiFeng? I mean just in case for to have a back up. Also thought already to even get me a second Owon or a spare main PCB at least.
(Of most of my tools I have more than 1 device of the same type and lots of spare parts for not to get stuck during some work should anything break down. More than 30 Tek TM503 plug ins I have build by myself when I was with Tek, all from spare parts! They liked that inofficially because it's the best training programm at all. We knew the machines down to the last screw and wire. Quite some of the technicians back then had their private side projects manufactoring quietly for the home lab)
Later I will check further and already have made some pics of a working Owon in exploded view...
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Hi Sarasir,
Sounds like you are making fine progress! I don't have much to add this time so for now I just want to cheer you on! :-+
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Hi TomC,
no, again in the shit. It stopped again today. Think I have to go back to the power lines and check all through. There are still strong spikes. Just tested briefly on a good point yesterday and thought thats it. All too much improvised at the moment and I'm not sure yet if the ADC has gotten a scar or not. Tinkered on the switcher a bit to adjust it to exactly to 1.9 (searching a little container full of SMDs for the right resistor can take half a day sometimes)
Some times I'm a bit too easy and want a quick result. But also had no idea that these chips are so sensitive. Feels like in the old days - remember Reticon BBD lines?
So back to step by step....
And have to read through the ADC sheet. Now the problem is no trace at all on the display and allways 'Ready' mode but the knobs do move their respective indicators... And when touching Owons ground on certain points with the 475A's probe ground lead the brightness steps through. So sometimes it even shows some humor..
You lucky one, tomorrow to the dentist again. Another disaster perhaps.
But worked on a good and hot piece of music today just to say something positive.
And on every cloud there is a silver lining.....
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Hi TomC,
no, again in the shit. It stopped again today. Think I have to go back to the power lines and check all through. There are still strong spikes. Just tested briefly on a good point yesterday and thought thats it. All too much improvised at the moment and I'm not sure yet if the ADC has gotten a scar or not. Tinkered on the switcher a bit to adjust it to exactly to 1.9 (searching a little container full of SMDs for the right resistor can take half a day sometimes)
Some times I'm a bit too easy and want a quick result. But also had no idea that these chips are so sensitive. Feels like in the old days - remember Reticon BBD lines?
So back to step by step....
And have to read through the ADC sheet. Now the problem is no trace at all on the display and allways 'Ready' mode but the knobs do move their respective indicators... And when touching Owons ground on certain points with the 475A's probe ground lead the brightness steps through. So sometimes it even shows some humor..
You lucky one, tomorrow to the dentist again. Another disaster perhaps.
But worked on a good and hot piece of music today just to say something positive.
And on every cloud there is a silver lining.....
Sorry to hear that!
I think it's possible that the symptom, always in ready state, may indicate that the ADC is not providing output data and as a result there is no trigger. Just wondering, does the scope produce a trace if you force the trigger? Hope is just a problem with the supply and not a damaged ADC!
Never heard of Reticon BBD lines until now! In case someone else is curios, here is a link that seems to explain how they work.
http://mysite.du.edu/~etuttle/electron/elect39.htm (http://mysite.du.edu/~etuttle/electron/elect39.htm)
Good luck at the dentist!
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Has anybody else gotten the Owon PC side software to work under Win7 Home Premium?
I read the help file, did the dance as suggested as far as turning on "Test Mode", etc.
No dice...
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Hi Skimask,
If you are talking about the Oscilloscope analysis software, yes, It's been working on both my laptop and desktop running Win 7 Home Premium 64 bit. Not quite sure what you mean by "Test mode", but it's been a while since I installed the drivers and software.
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Ya, I'll be damned if I can get it to work and/or connect, Win7 H/P 64b
The "test mode" I speak of is mentioned in the OWON software "Help" section, where it has you put Windows into the "test mode" where it basically takes any set of drivers and runs with it without asking for digital signing or any of that stuff.
At any rate, asks for the drivers, loads the drivers, won't connect, plain and simple. Now...maybe I'm forgetting to turn on something on the 'scope itself, or move a setting. I dunno. Didn't see anything specific in the PDF manual.
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Is anyone else's 7102 microphonic? I noticed that tapping the case between the two channel BNC inputs caused channel 1 voltage to move a little, and if I flick the case with a finger nail I can get up to ~200mv damped sinusoidal (ish) waveform.
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Ya, I'll be damned if I can get it to work and/or connect, Win7 H/P 64b
The "test mode" I speak of is mentioned in the OWON software "Help" section, where it has you put Windows into the "test mode" where it basically takes any set of drivers and runs with it without asking for digital signing or any of that stuff.
At any rate, asks for the drivers, loads the drivers, won't connect, plain and simple. Now...maybe I'm forgetting to turn on something on the 'scope itself, or move a setting. I dunno. Didn't see anything specific in the PDF manual.
Did you download the Labview package from the Owon site?
One of the folders in this package contains the USB driver. I'm pretty sure that's what I used to install the driver back when I first got the scope.
The PC software packages that I have don't seem to include the USB driver although the instructions for installing it are included.
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Is anyone else's 7102 microphonic? I noticed that tapping the case between the two channel BNC inputs caused channel 1 voltage to move a little, and if I flick the case with a finger nail I can get up to ~200mv damped sinusoidal (ish) waveform.
Does this happen with nothing connected to the BNCs?
If you had the probes connected try with nothing connected. It could be a bad connection at the BNC.
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Is anyone else's 7102 microphonic? I noticed that tapping the case between the two channel BNC inputs caused channel 1 voltage to move a little, and if I flick the case with a finger nail I can get up to ~200mv damped sinusoidal (ish) waveform.
Yes it is some amount microphonic. Some analog front end versions more than others but I have never done deep tests and compared versions because normally this is not real problem. It means that some individual scope may have more and some less. And also Owon is not alone. This is common problem. But it depends highly what component are used, layout on the PCB, and whole mechanical construction.
Perhaps main reason (but not exactly whole only one reason) is this:
Microphonic Effects
Of much less concern, yet still important, especially
in audio applications, is the microphonic or piezoelectric
effect. Barium titanate which is the base ceramic
material for most dielectric systems will exhibit microphonic
effects. It is not very difficult to take a Y5V
capacitor and put a DC bias with a small signal 1kHz
sine wave and get the capacitor to “sing”. Tantalum
capacitors exhibit no microphonic effects. The experiment
done by AVX involved the opposite phenomena
whereby the part was shaken while under bias and the
resulting generated voltage was measured.
Quoted text is from:
COMPARISON OF MULTILAYER CERAMIC
AND TANTALUM CAPACITORS
by Jeffrey Cain, Ph.D.
AVX Corporation
I can tell for curiosity that example usual coaxial cable is "microphonic", you knock it and all changes, you bend it and all changes..etc... you sing and you can listen it using coaxial cable as microphone (but of course these findings need special equipments)
Try use sensitive and accurate VNA without special cables... with normal coaxial cables all are bullshit and today you measure something and next day you have moved cables and all have changed... PCB's are microphonic... L,C,R all change with mechanicalvibration. But these are of course low level changes and nothing meaningful in this particular case.
Owon front end (and also many other manufacturers) some components are highly microphonic and it can see in races if you knock / vibrate / shock amplifier/attanuator circuit.
In many "high end" and "state of art" test equipments some sensitive parts / blocks are well isolated from external mechanic noise and acoustic noise and also used many construction details for minimize these effects in eleronic circuits but also mechanic. But these kind of equipments are made and developed by well experienced real professionals and this kind of professionals are quite rare.
In oscilloscope front this level of microphonic is normally not real problem in normal use.
If someone find this more and some less, main reason is that there have been many changes in front end circuit. Some small changes in different versions but also there have been some major changes. (example from IC amplifier to dual pathway discrete fet amplifier.) Then, also some component may have changed in different manufacturing lots. (example same voltage, same capacitance but different manufacturer and/or type.
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Here one example with other brand of scope.
Shock made using "medical doctors" rubber hammer. (This is good electronic workshop tool)
Shock directed axially to input BNC outer GND part.
(shock was "hard" and not this "knock" what doctors normally use.)
This rubber hammer do low frequency shock (as can see)
Input BNC open and 5mV/div and 1Mohm impedance set.
It can also repeat with example tektronix analog scopes. But taking image without triggered scope camera is "impossible".
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Did you download the Labview package from the Owon site?
One of the folders in this package contains the USB driver. I'm pretty sure that's what I used to install the driver back when I first got the scope.
The PC software packages that I have don't seem to include the USB driver although the instructions for installing it are included.
I Google'd "labview Owon" and came up with something completely different from "Owon PC software".
Downloaded that. Works now.
Pretty slow updating on the PC though...almost unusable. But good enough for me.
Thanks for the tip ...< ->beer >...
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Is anyone else's 7102 microphonic? I noticed that tapping the case between the two channel BNC inputs caused channel 1 voltage to move a little, and if I flick the case with a finger nail I can get up to ~200mv damped sinusoidal (ish) waveform.
Does this happen with nothing connected to the BNCs?
If you had the probes connected try with nothing connected. It could be a bad connection at the BNC.
It happens with nothing connected, I assumed it would be down to ceramic caps in the front end.
I just powered it up and took the following pics with nothing connected to either input (sorry for phone pics, Owon software doesn't seem to like Windows 8 64 bit).
This is a fairly gentle tap:
(http://i905.photobucket.com/albums/ac257/mikerj/WP_20140625_004_zpsa531033a.jpg)
And this is a hard flick with a finger nail:
(http://i905.photobucket.com/albums/ac257/mikerj/WP_20140625_003_zps93204dd8.jpg)
Pk-pk voltages look worse than I originally thought.
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It happens with nothing connected, I assumed it would be down to ceramic caps in the front end.
I just powered it up and took the following pics with nothing connected to either input (sorry for phone pics, Owon software doesn't seem to like Windows 8 64 bit).
This is a fairly gentle tap:
And this is a hard flick with a finger nail:
Pk-pk voltages look worse than I originally thought.
What I see on my scope with a hard flick with a fingernail is about what you see with a gentle tap!
I'm not sure if what you are seeing is just normal micro phonics as rf-loop describes in his post, but to me, it seems a bit excessive, like a bad connection someplace in the front end. If your scope is under warranty I would contact Owon and attach the pictures to the e-mail. If you just give them a link to photobucket or some other web drive they may not be able to see them in China.
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I Google'd "labview Owon" and came up with something completely different from "Owon PC software".
Downloaded that. Works now.
Pretty slow updating on the PC though...almost unusable. But good enough for me.
Thanks for the tip ...< ->beer >...
So it seems that you have the USB driver working now (with Labview). As far as I know this is the same USB driver that the PC software uses, so I would think the PC software should also be working now! Have you tried it?
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Ya, that's what I meant. It all works now, but again, very slow updates from 'scope to PC. Better than nothing???
Although my little Xprotolab Portable updates many times per second vs. The Owon software at about 1 FPS.
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Hi TomC,
came to the decision to bring the 1.9V switcher back to the main PCB because obviously the ADC needs a very low impedance supply. At least now it's clear why they have put this switcher there. The moment the mode switching wants to go from low power to normal mode probably sees a not stiff enough supply and refuses to go over. Thats my problem at the moment that ADC stays in low power mode.
Will put it in a small tin box to fit it in between the keys PCB and the main PCB.
Will take some time especially as I sit here with a swollen cheek and have to see the dentist again after a 4 houres session on tuesday....
And to the microphonic behaviour discussion:
Has any of you thought about the rectangular shields who are soldered just on three points?
If one of them is a bit loose it could make up something like a condenser mic!
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The scope is probably not in warranty. I bought it new, boxed and unused but it was bought by a previous over a year ago and never used. I'm quite happy to take it apart and have a look so I'll let you know if I find anything.
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The scope is probably not in warranty. I bought it new, boxed and unused but it was bought by a previous over a year ago and never used. I'm quite happy to take it apart and have a look so I'll let you know if I find anything.
Owon factory warranty is 3 year.
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This microphonic is sum of many things. Normally it do not affect measurements at all. It may be problem in some heavyvibrating enviroment as example in wechile etc. And even if this is any kind of problem it is easy to solve using sevral methods. If it is problem on the table this effect is easy to minimize.
Why it is so microphonic.
Construction is so that BNC connector go directly axially to PCB and there very sensitive area.
This outer shield of BNC is directly soldered to PCB. Knoc it and all force and vibrations go to PCB and its direction is worst possible
If BNC is first fixed to some metal base and after then example side direction from PCB situation is perhaps more easy. (as example in Siglent, Rigol DS1000 and many others)
In very very early version BNC did not go at all directly to PCB. It was not microphonic.
If want that mechanic vibration do not affect this construction need be different. It can still construct to inside these scope dmensions but very different mechanic. Also front amplifiers layout on PCB can do different and isolate bending forces by cutting PCB around amplifier sensitive parts so that even if main PCB have some bending vibrations/waves they do not bend front end amplifier.
But all these need new design.
Also some componet need carefully select. (specially some capacitors in front end)
Now it can ask - is it forth of this price?
Do not knokc and hammer your scope when you do sensitive measurements and this modification of working practices do not cost anything. It is free.
If you want measure nail knocs pleasre also put BNC cover cap on it. (Real BNC metal cap)
It enclose BNC input so that external electric field can not affect to 1Mohm around 10pF very sensitive input) Put your finger near to open input and agen you have electrical phenomenon which may wonder.
~
But If I want listen my water pump roller bearings I can connect nylon rod from bearing box shield to my scope BNC and "listen" with FFT these bearings condition ... ( 8) )
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Hi TomC,
came to the decision to bring the 1.9V switcher back to the main PCB because obviously the ADC needs a very low impedance supply. At least now it's clear why they have put this switcher there. The moment the mode switching wants to go from low power to normal mode probably sees a not stiff enough supply and refuses to go over. Thats my problem at the moment that ADC stays in low power mode.
Will put it in a small tin box to fit it in between the keys PCB and the main PCB.
Will take some time especially as I sit here with a swollen cheek and have to see the dentist again after a 4 houres session on tuesday....
And to the microphonic behaviour discussion:
Has any of you thought about the rectangular shields who are soldered just on three points?
If one of them is a bit loose it could make up something like a condenser mic!
Yes, I agree, getting the 1.9 supply close to the ADC sounds like the best course of action! Let's hope that's enough to the get the ADC back into action.
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The scope is probably not in warranty. I bought it new, boxed and unused but it was bought by a previous over a year ago and never used. I'm quite happy to take it apart and have a look so I'll let you know if I find anything.
In case you haven't seen it yet, here is a link to a video that shows how to take the SDS7102 apart. Just be careful with the Power button and hold it down while taking the cover off, this is not shown clearly in the video.
SDS Teardown (https://www.youtube.com/watch?v=Zct3Ircz6nY#)
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Sorry side tracking again the present long stretching trend a little.
The purpose of this post is to let others who like me lost the factory calibration to know: DIY "factory" calibration of SDS7102 is doable. In fact, no inside pots need to be turned; it is all digital from the front/side panel.
For those who may not know, the tx file on your SDS7102 contains 194+ machine specific calibration constants.
I accidentally overwrote the factory tx file (the os and fp files too) on my osc and I did not have a backup (not equipped to do the backup). The problem with os and fp was easy to correct. But the problem with tx is not. Some days ago I asked around about a sample tx file for a certain SN range.
I did not get any answer back; Then, I proceeded to do my own DIY calibration: the unofficial "factory" style. To calibrate the 194 constants has been tedious, but I am about 80% done. The only thing left is the trig-level offset calibration. It involves 24 constants, but their calibration requires more trail-and-error process.
When I have more free time and if there is an interest, I will summarize the calibration steps in a new thread.
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Hi onlooker,
I have no idea how to look at, read, or extract the tx file from the SDS7102. Perhaps other members that may have a scope within the target serial number range are in the same boat, and therefore unable to help you. My scope's serial is 1246320 which I think is too new for your needs. However, I'm pretty sure some of the other regulars in this thread own scopes of the proper vintage. Try posting more information on how to access this tx file and perhaps one of them will be willing to help you! :)
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TomC,
Thanks for replaying. I guess I did not make myself clear.
I have already figured out how to do the calibration without a know good tx file. In fact, I have mostly done my calibration. The remaining part is just a matter of time.
But, I also like others in the same boat as me to know it is doable and when I have time I will share the steps in a new thread. To write up the whole thing in a concise manner takes time.
By the same token, if someone has something to share about factory calibration, I will be interested to read.
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hi TOM
some Guru say SDS7102 ( Owon ) not good and Riogol more better . are you agree ?
can you get video and put here of your Owon scope ?
i stay between Owon or Rigol to choose ? :phew: :-BROKE
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Hi mohandes,
It all depends on what's important to you, or if you only use your scope for your hobby like me, then it probably only depends on what you like! :)
For example, I attached a couple captures from the VCO of a modified TV tuner that I plan to use to build a HF RF generator. I like to be able to view these HF signals on the scope, I don't think I can get a Rigol in the SDS7102 price range that can do this.
Try to figure out what's important to you, or what you like. That will probably help you more than anything else to make your decision!
Edit:
The smooth appearance of the signals in the attached captures is due to sin x interpolation. In practice, at 1GS/s, this works without much aliasing to around 400MHz. In theory, with a perfect filter, it should work to around 500MHz.
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It looks that newest FW (have been available from Owon some weeks) give max 260 wfms/s
With settings: 1us/div, one channel, 1k mem, dots and not any menu open and trig auto.
With settings: 50ns/div, other sets same give 250wfms/s
With eyes and real signals this improvement looks visually even more
Sad that it do not have intensity grading in normal display mode. There is 8 step intensity grading only in persistence mode but persistence drops wfms/s rate to low.
Old "up to" limit was 35 wfms/s. (it was just like conventional series processing DSO )
Also with other settings there is more or less improvement if compare to old.
max 35 to max 260 is nice FW improvement without touching HW.
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Yes, I have seen the same behavior after the fw upgrading.
In some situations the improvement is huge, only by fw.
For me the only big missing is the Vertical Fine adjustment and the appear of all measurements in real time.
I don't think so that these changes are difficult from Owon.
Unfortunately, Owon's customer feedback politic wasn't appropriate.
Personally, three times I sent my suggestions for fw changes, but never had an answer about this.
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Hi TomC + +
I'm not so sure any more if it was my mods that caused the present problem I have: No Auto triggering - switching to Auto it will go back to Ready and stay there. I came to this conclusion because if I let it on running for an half an hour or so it slowly starts to auto trigger again and after about an hour it stays in Auto mode and time base is running but shows no input signal but HF oscillation like on both traces.
Obviously there is a thermal problem and it was comming slowly as I remember having seen that already long time ago but in the the beginning it came always back, but taking more and more time increasingly over the many days I'm tinkering with this thing now.
And I remember there was also a moment when I could do away with it by softly knocking on or even bending the main PCB a little as it seems.
Anyways, ordered another SDS 9202 yesterday to have a backup. I have checked the price for the TI ADC and it's about 1000$ plus german VAT and customs - and no samples of this available. That would be more or about the price for the whole scope here in Germany (1100.- €).
And I think my idea to get away with all switchers by connecting them with long wires to the scope was just unfinished thinking. This way I was creating an even bigger antenna for the opposite (to the BNCs) radiation side maybe not so much for the switcher noise but for the digital noise generated by the main PCB. I have overseen this completely. On the other hand by exploring the extremes often it helps to find the optimum some where in between.
Seems to become a very long story....
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Hi Sarasir,
Sorry to hear this thing is still giving you fits!
If I understand correctly it only gives you trouble when in autotrigger and the other trigger modes work correctly. To me that sounds like something external to the ADC, probably in the main board, but not a faulty ADC chip in my opinion. Based on the warmup and sensitivity to vibration or bending symptoms I would look for a cracked circuit trace under a microscope or magnifying glass.
As far as spares, have you checked with Owon for availability and price for the main board? Hard to believe that the price for just a chip would be that high, no wonder Owon doesn't source from TI.
That's all I can think of for now. Let me know of any progress or new findings! :)
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Hi TomC,
it doesn't trigger at all during warm up and as the ADC is the chip that gets hot pretty quick and as it also needs time for this heat to spread around to reach the foulty spot, I guess that this is also an indicator for that the problem is located somwhere else.
It's hard to scrutinize that board cause it's a multilayer and all blue and it could be everything in fact - cold soldering under a chip or bad contact inside a chip, whatever... with cracked traces to my eyperience you have to deal with rather in older machines (after many warm up/cool down cycles).
Also thought to get me a spare main PCB but first I prefer to get another new, complete and tested scope.
This will also give me the abibillity to do the 'oil-can-test' next - remember? - to get more, new and different experiences with the discussed phenomenons.
...and no stock of that chip over here in Europe only in USA one or two distributers have it...
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Hi Sarasir,
Just wondering, have you thought of using one of those Freon based sprays to try to localize the problem area once the scope starts working after warmup?
Don't know what the "oil can test" is as related to electronics, I know they refer to that when testing metal for its ability to bend and regain its initial shape without braking.
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....I mean to put the thing into an emty oil can (5 litres of greek olive oil was in before) and check if there is still radiation on the BNCs.... and what would the freon help? I used it for cleaning....and didn't know about that shape test - btw. sorry for my english...
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....I mean to put the thing into an emty oil can (5 litres of greek olive oil was in before) and check if there is still radiation on the BNCs.... and what would the freon help? I used it for cleaning....and didn't know about that shape test - btw. sorry for my english...
I remember now about your plan with the greek olive oil can! For some reason 'oil-can-test' just reminded me of the metal test.
The Freon based spray (may be called something like Freeze-It) is used to quickly cool a spot on the board or a component, this often causes an intermittent or heat sensitive problem to reappear or in some cases to temporarily disappear.
http://www.chemtronics.com/p-778-freeze-it.aspx (http://www.chemtronics.com/p-778-freeze-it.aspx)
By the way, I think your English is excellent!
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Hi TomC,
I now now what you mean. Of course I have such a spray but didn't really feel to use it, rather a hair dryer to heat it up more quickly. Of course cooling it down then partly with the spray could perhaps reveal the area where this temperatur problem is located but what to do then? And I still think that the ADC might have suffered some damage as well because when the time base is running it still doesn't show the general input noise or any signal applied but only HF oscillation. So quite likely there are two problems, and one of them - the ADC - I'm not able to rectify at the moment.
Rather feel to get me another main PCB and replace it and use the broken one to trace down the circuit as there is no way to do that without taking off many components e.g the ceramic Cs for to evaluate them and also to be able to follow the traces somehow.
At the moment I'm shaping the oil can and I'm looking forward to what that test will show.
A soon as I know more I will post it.
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It looks that newest FW (have been available from Owon some weeks) give max 260 wfms/s
...
max 35 to max 260 is nice FW improvement without touching HW.
I can confirm, it does indeed look and feel a lot faster updating with the latest firmware update :-+
But actually sometimes I miss the old slower updates, as it would give a nice stable trigger on noisy signals without having to adjust the hold off :D Guess you just can't make everyone happy. Nah, it's a nice improvement, a bit like a scope upgrade for free.
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What version is your firmware?
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What version is your firmware?
Independent of what version read in Owon display after upgrade, version is this.
After update it may show example 3.8. - this I have seen.
(but I do not know if some manufacturing patch show different version number after update)
Note: Do NOT even try for different serial numbers. If your serial is not in list then it is game over (can not).
(Before update be sure your USB connection with patch software works.
During update it need care that USB connection and PC continuous working do not fail/break.
(shut off all other works in windows what can any time do what ever.)
SDS7102UP3.4
14-05-29 17:15:52
The firmware applied to the products with following production batch / serial no. -
SDS71021312xxx, SDS71021319xxx, SDS71021327xxx, SDS71021344xxx, SDS71021352xxx, SDS71021407xxx, SDS71021414xxx, SDS71021418xxx,
Change log - :
1. XY mode - persistence function added ;
2. waveform refresh rate improved ;
3.waveform cutting/ recalling function added;
4. autoset - waveform recognition;
5. channel invert bug fixed;
6. probe attenuation compensation;
7. recorded waveform exported to USB drive
8. automatic measurement - 4 more options available
9. vertical position over-speed movement bug fixed
(Before update be sure your USB connection with patch software works.
During update it need care that USB connection and PC continuous working do not fail/break.
(shut off all other works in windows what can any time do what ever.)
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Hi all,
This thread goes on and on and on :), been browsing through most of the pages and have watched Marmad review and also Daves video look at the 300MHz version.
I am going to buy my first DSO soon and will be using for a multitude of projects, digital designs with SMPS using TI C2000 and other projects with the TIVA kit.
I have been looking at the Owon SDS7102V and also the Siglent SDS1102CML, both seem pretty capable and currently favouring the Siglent. Curious if anyone has experience of the 2 or similar and how they would rate them.
I also noticed on page 162 of this thread Owon has released a new firmware, which seems to sort the refresh issue out. Is Owon's customer service listening more and trying to resolve the issue that people have been talking about.
Cheers,
Ant
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What version is your firmware?
Mine shows 3.8, but be aware the update is not available for all hardware versions, although mine isn't exactly new, it was included and the update is a nice performance improvement.
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In the About menu, mine shows 2.8.1.6
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In the About menu, mine shows 2.8.1.6
If your scope is in the underlined serial number range that's what you are supposed to get. Apparently the hardware in that range doesn't support the new features available in firmware version 3.8. However, the same windows file (version 3.4) is used to upgrade scopes to different firmware versions.
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Ah, thanks for clearing this up for me. My SN is sds710211520, so I am current with my hardware.
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Hi TomC + rf-loop,
just briefly, It works! The oil can around the Owon connected only to the input BNC makes almost all radiation disappear (Also added cores to the power cables of all gear used: Owon SDS 9302, Tek SG505 audio generator and Tek 475A 250MHz scope to monitor Owons input).
I dare to say that a plain sheet of metal does not act as a coil and therefore there are no reactances present created with stray capacitances as rf-loop predicted (as far as I remember).
Will take some photos of the set up and post them as soon as possible.
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Sounds good! :-+
If this is your new 9302, keep in mind that the new style PSU may be partially responsible for the experiment results. Will be waiting to see the photos! :)
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....yes I noticed that the new one is remarkably better. Whereas my first one filled almost the whole screen with noise this one just fills less than half but that is still a bit too much.
Never the less, what I did is a simple before and after test, and I just noted the noise displayed on the 475A with the Owon not caged versus to having it caged...
The amount of reduction my experiment shows is what to focus on not the absolute readings I would say.....
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Hi TomC ++,
so here my pics:
#1 : That's how it started, just the SDS9302 at 2mV/Div and the Tek SG505 with output on.
#2 : Same but just screen shot.
#3 : As #1 but SG505 output switched off.
#4 : As above but just screen shot.
#5 : Just Tek SG505 and 475A (at max sensitivity - 5mV/Div) together.
#6 : As above, 475A screen shot only.
#7 : Tek SG505 and 475A with SDS9302 not shielded.
#8 : As above 475A screen shot.
#9 : As above SDS9302 screen shot.
#10 : Modified oil can.
#11 : Owon put into oil can - 475A screen shot.
#12 : As above - display detail version 1.
#13 : As above - display detail version 2.
#14 : As above but SG505 output Switched off.
Screen shots of the caged SDS9302 I will do after I cut a window in my oil can. And I think about some kind of metal grid to cover the window which then I can put on and off.
Perhaps I have one of this very fine meshes Tek offered as an option back then but have to search my stock - don't know yet...
The detail pics (#12+13) show very little residual noise on the peak of the sine waves after the Owon had to go into the can and the last pic also shows what's left of the spikes you can clearly see on both displays as long the Owon is 'free' (#7+8+9).
Last thing to add: The Tek 475A connected to the Owon 'swallows' a certain amount of Owons emissioned noise due to its solid mass some how (another effect for you to think about - I have no absolute clear picture yet because where does it go then? Perhaps is it just spread out more widely?). So for the moment its just the reduction achieved by caging the Owon that I can show (pics #7...9 versus #11...14).
So hope all pics are OK so far (turned 475A's intensity up to make anything in the backgroud visible but that also blurres the trace a bit).
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Hi Sarasir,
Very detailed post with good photos! :-+
My preliminary thinking is as follows:
I think it's possible that some of the noise is coming from an external source. Since the 475 is better shielded the noise is less apparent on its display versus a 9302 outside the oil can. The oil can provides shielding from external sources so when the 9302 is in the oil can the 475 reports very little noise.
I think it's also possible that the noise reduction when the 475 is connected in parallel to the 9302 may be due to the input capacitances of the two scopes also being in parallel. As a result more of the high frequency noise is dissipated reactively.
Let me know what you think of that hypothesis, like I said, this is just some preliminary thinking! :)
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Hi TomC,
what you mean by external source? The time I made the pics no other noise was present with the Owon disconnected from mains (the terrible noise I had the other day never came back again after it disapeared the third day. Indeed must have been some HAM radio guy or whatever.).
All noise you see in the pics is generated inside the Owon, absolutely no doubt.
Theoretically the added 475 input capacitance of 20pF might reduce the displayed noise a little but I don't think that is significant. And the set up is the same with and without the oil can so why dealing with it?
The question why noise goes down when connecting the 475 to the setup was just btw. The same thing might happen as well if connecting a cubic of solid iron of 1m x 1m x 1m to the setup common ground. Must have something to do with the energy needed to drive a big mass - or antenna as well if you want - with HF.
Only the difference between the pics taken with the Owon in and out of the can counts in my opinion.
The displayed noise of the 475 shows just one snap shot of the noise due to it's more precise triggering whereas the Owon's display is rather unstable, has a tendency to trigger on different spikes each sweep.
But I haven't closely checked it's trigger abilities yet.
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Hi Sarasir,
Based on the pictures and your description it's difficult for me to find a plausible explanation for the noise difference and exclude the influence of unknown, but real, external noise sources.
If all the noise was generated inside the Owon the oil can would block most of it from escaping from its confines. However, I don't see how it could prevent common mode currents inside the Owon from being converted to differential mode currents when faced with an impedance imbalance on the coax. So in my mind, a plausible explanation is the influence of the oil can over external noise sources, in other words, its ability to block most of the external radiations and prevent them from reaching the Owon. With an unshielded Owon the influence of external noise sources would account for an increase of common mode currents within the Owon and as a result more visible noise. The reverse would be true when the Owon is inside the oil can. On the other hand, the 475, which by itself registers very little noise, is built inside a metallic cabinet with probably better shielding characteristics than the oil can. This seems to be consistent in my mind with the theory that some of the noise comes from external sources.
There are a couple of other things that in my mind may play a part in the big picture. Inside the oil can the Owon's screen, a known emitter of near field radiation, is prevented from spilling it onto the environment. However, looking at the pictures, I don't see any of the coax cables close enough for this to be a mayor player on the experiment results. The other thing that comes to mind is the role that the points where you chose to ground the shield may have on existing common mode currents inside the Owon. By redirecting some through a potential shorter path there may be fewer available at the coax when faced with an impedance imbalance. However, without a way of visualizing these currents choosing the best grounding points may be a daunting task.
Anyway, let me know what you think! :)
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Hi TomC,
I'm sorry my friend but I think you still have not got the big picture yet!?
Will give you another picture:
When you heat up a pot with water and it starts boiling then steam is created. That steam will go into the environment, cool down, becomes water again that settles down wherever around.
With the above process going on the water inside the pot will become lesser.
If you had another pot filled with water placed on the same elevation level as the boiling one and connected both with a pipe at their bottoms then water would flow from the cold pot over to the boiling one (communicating pipes - physics!) - OK?
Now, if you would catch all steam with a cold shield the steam would condense and by conducting the condensed steam - now water again - back to the boiling pot you could take away the pot with the cold water because the water level in the boiling pot now would stay the same all the time - loop is closed!.
Now look at Owons emission! As long as they spread out 'new spikes have to be supplied' at our point of interest - the input BNCs (and it's exactly this point only because we choose it out of the fact that we want to connect something else to it that should not see what's going on inside!) - because the flow of emission must be counterbalanced due to the nature of this universe.
The moment all emissioned spikes are conducted back to this point all spikes are just running in circles but are not drawn ore pushed anymore from or into the outside world (An AC system here compared to the steam model which is a DC system - therefore I speak of drawn and pushed.).
What the oil can does is exactly that - catching all emissions of the Owon and conducting them back to the point we choose as the zero point.
Once more: It's closing the loop inside a system so nothing unwanted from the inside of that system can be seen anymore from the outside world!!! (In a way also a philosophical principle)
Have you got me now?
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Hi TomC,
I'm sorry my friend but I think you still have not got the big picture yet!?
Will give you another picture:
When you heat up a pot with water and it starts boiling then steam is created. That steam will go into the environment, cool down, becomes water again that settles down wherever around.
With the above process going on the water inside the pot will become lesser.
If you had another pot filled with water placed on the same elevation level as the boiling one and connected both with a pipe at their bottoms then water would flow from the cold pot over to the boiling one (communicating pipes - physics!) - OK?
Now, if you would catch all steam with a cold shield the steam would condense and by conducting the condensed steam - now water again - back to the boiling pot you could take away the pot with the cold water because the water level in the boiling pot now would stay the same all the time - loop is closed!.
Now look at Owons emission! As long as they spread out 'new spikes have to be supplied' at our point of interest - the input BNCs (and it's exactly this point only because we choose it out of the fact that we want to connect something else to it that should not see what's going on inside!) - because the flow of emission must be counterbalanced due to the nature of this universe.
The moment all emissioned spikes are conducted back to this point all spikes are just running in circles but are not drawn ore pushed anymore from or into the outside world (An AC system here compared to the steam model which is a DC system - therefore I speak of drawn and pushed.).
What the oil can does is exactly that - catching all emissions of the Owon and conducting them back to the point we choose as the zero point.
Once more: It's closing the loop inside a system so nothing unwanted from the inside of that system can be seen anymore from the outside world!!! (In a way also a philosophical principle)
Have you got me now?
Paradoxically, I agree with a lot of what you are saying, but at the same time, I also still agree with what I said on my post! :)
As you, I see the oil can (shield) as a means of confining the Owon's radiated emissions. As they encounter this barrier most of these emissions induce shield currents and as a result loose most of their energy while a few bounce back toward the Owon. So in that sense I agree that these unwanted radiated emissions from the inside can no longer directly influence the "outside world".
However, I don't think that the shield can provide a mythical or philosophical barrier that somehow corrals within its confines all the conductive common mode noise generated by the Owon. I can accept that It may short circuit some of it depending on the ground points chosen, but not to the extent that the inside and outside test results would require. So I still think that part of the noise visible during the outside test originates elsewhere.
In any case, regardless of the theoretical explanation, I think the experiment clearly demonstrates that shielding the Owon results in significantly better noise immunity. Whether all the noise originates within the Owon or whether it partially originates external to the Owon doesn't change these facts! :-+
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Hi TomC,
As to the aggreements just one example first: The 475 does exactly what it should do and that is to register whatever signal is applied to the center contact of it's input connectors referred to the sleeves (confined to it's specs of course).
... it's neither a mythical nor a philosophical barrier, it's a physical barrier. Just read again about the cage of Faraday... and if you want tell me about it's bandwidth limits. Haven't checked that yet I must confess.
...and now I do shout intensionally:
'THERE IS NOOO SIGNIFICANT OR RELEVANT NOISE PRESENT IN THIS ROOM HERE! SEEERIIIOOOUUUSLY!!!'.
Please, will you believe that eventually.
Do you really think I wouldn't notice that? (What you think Tek and before R&S and before Uher paid me for? For to be a bum or what? I have solved every technical problem that could be solved, sooner or later - some just needed a bit more thinking)
(I hope you still have kept your humor)
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Hi Sarasir,
I took the time to read several articles on shielding theory, Faraday cages etc. I was expressly looking for something that would substantiate your theory that nothing, including conductive common mode currents can scape the shield. That only seems to be possible on a perfect shield (Faraday cage) with no openings which is hardly the case here. Everything I see reinforces the theory that shields are effective for radiated emissions, but can't stop the conductive components already present on the interface cables going in/out of the enclosure.
So I don't know what else to tell you!
Just a suggestion, can you try finding another source that substantiates your theory and post it! Of course I understand that this may not be possible if you think that this is an original discovery that no one ever thought of before.
As far as my theory is concerned, that's all it is, a theory, and believe me, it doesn't bother me at all if I'm wrong, that usually helps me retain the right answer/theory better!
And I don't doubt your technical ability and qualifications! I just can't come up with a different explanation for the experiment results, so at the risk of being embarrassingly wrong by persisting, I still have to say that based on this latest research my opinion still hasn't changed! :)
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Hi TomC,
what you mean by external source? The time I made the pics no other noise was present with the Owon disconnected from mains (the terrible noise I had the other day never came back again after it disapeared the third day. Indeed must have been some HAM radio guy or whatever.).
All noise you see in the pics is generated inside the Owon, absolutely no doubt.
Theoretically the added 475 input capacitance of 20pF might reduce the displayed noise a little but I don't think that is significant. And the set up is the same with and without the oil can so why dealing with it?
The question why noise goes down when connecting the 475 to the setup was just btw. The same thing might happen as well if connecting a cubic of solid iron of 1m x 1m x 1m to the setup common ground. Must have something to do with the energy needed to drive a big mass - or antenna as well if you want - with HF.
Only the difference between the pics taken with the Owon in and out of the can counts in my opinion.
The displayed noise of the 475 shows just one snap shot of the noise due to it's more precise triggering whereas the Owon's display is rather unstable, has a tendency to trigger on different spikes each sweep.
But I haven't closely checked it's trigger abilities yet.
I do not know exactly how you have connected Owon+Tek parallel to signal generator but I believe this connection add much more than just pure 20pF Tek input capacitance. So, this connection may reduce much more bandwidth than may expect if think only Tek input 20pF. You can try. Connect fast edge instead of this sinewave and yoy can see high reduction in risetime, and this Network may also peaking with several frequencies die to its possible impedance mismatching.
Just for clariy. If connect 50ohm cable to 1MOhm input and look 50ohm cable free end. There is this cable cpacitance and inductance "Network".
Also I note that you use 2mV/dif in Owon. There is 20MHz BW limit. This noise frequency components have lot of over 20MHz frequency components what are now highly attenuaated and peaks are much lower than they really are.
If you want see around same with Tek oscilloscope and Owon ypu need do impedance matched real splitting Network from Signal gen output parallel to both scopes. Other ways can not see any real data. But of course also this kind of simply test is useful.
Other thing is very big difference if we think how analog oscilloscope show noise what is "random" with scope eyes. This is real thing what have discussed and studied in many places. Owon itself can show much more noise than this Tektronix. It can proof if you look some signal sou´rce what produce some known signal added with some random noise peaks.
Fact, I believe, is of course that this noise in this case is coming from Owon.
Btw, for trigger stability there is adjustment in Owon trigger settings. (HF reject)
---------
About noise displaying with digital scope or analog scope.
(this is partially for these peoples who do not know and randomly read this topic and look these pictures where Tek analog scope do not show nearly any noise (or only small amount) and Owon screen is full of noise.
Try with 5ns width pulses with 10ms period. What you can see on Tek275 display and what can see on the Owon display?
On the Tek display nearly nothing or nothing and Owon show just clean full pulse without any problem. Same for noise, depending noise characters and what signal is trigged.
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Hi Sarasir,
I took the time to read several articles on shielding theory, Faraday cages etc. I was expressly looking for something that would substantiate your theory that nothing, including conductive common mode currents can scape the shield. That only seems to be possible on a perfect shield (Faraday cage) with no openings which is hardly the case here. Everything I see reinforces the theory that shields are effective for radiated emissions, but can't stop the conductive components already present on the interface cables going in/out of the enclosure.
So I don't know what else to tell you!
Just a suggestion, can you try finding another source that substantiates your theory and post it! Of course I understand that this may not be possible if you think that this is an original discovery that no one ever thought of before.
As far as my theory is concerned, that's all it is, a theory, and believe me, it doesn't bother me at all if I'm wrong, that usually helps me retain the right answer/theory better!
And I don't doubt your technical ability and qualifications! I just can't come up with a different explanation for the experiment results, so at the risk of being embarrassingly wrong by persisting, I still have to say that based on this latest research my opinion still hasn't changed! :)
Hi TomC,
the shield is connected only at one point to the Owon and that is at the input BNC(s).
So all that is conducted by the shield is radiated emissions from the Owon (of course the shield will also sense all radiation from outside e.g. from mobile phone transmissions to TV broadcasts but those levels are far down compared to the noise we are dealing with - at least here where I'm working, and e.g. my Mobile is always off when I'm at home)
Why do you say hardly? The only open hole in the oil can shield is for the power cord and on this cord I have put 4 cores, with the cord wound around one time on two of them so to pass it through twice.
The other hole is closed by the BNC coupling that also connects the shield to the BNC connector.
Even though the shield is not perfect - just thin iron tin and not silver anodized - it brings down the noise to a level where it almost can not be seen anymore on the 475 whereas before the spikes where quite high.
And I never said that nothing can scape the shield! It's always a question of power what can go through what and what not.
And it's certainly not my invention. As I already mentioned inside of professional machines this principle is utilized time and again.
And I do not need any source to proof anything if I see that my theory works. Yes, sometimes it is good to read that you're on the right way or you might get some additional ideas.
Sorry, but I have to question the picture you have of my qualification because again you came up with this external noise crap implicating that I'm not able to verify whether the room here is clean or not. One time you may ask or say that but second time it's almost an insult for me.
And in general, of course it's not a problem at all what you beliefe or not, that's absolutely up to you and I'm not angry or whatever. It's just fun to fight for the truth and through our discussion my picture of the discussed mechanisms just clears up more and more.
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I do not know exactly how you have connected Owon+Tek parallel to signal generator but I believe this connection add much more than just pure 20pF Tek input capacitance. So, this connection may reduce much more bandwidth than may expect if think only Tek input 20pF. You can try. Connect fast edge instead of this sinewave and yoy can see high reduction in risetime, and this Network may also peaking with several frequencies die to its possible impedance mismatching.
Just for clariy. If connect 50ohm cable to 1MOhm input and look 50ohm cable free end. There is this cable cpacitance and inductance "Network".
Also I note that you use 2mV/dif in Owon. There is 20MHz BW limit. This noise frequency components have lot of over 20MHz frequency components what are now highly attenuaated and peaks are much lower than they really are.
If you want see around same with Tek oscilloscope and Owon ypu need do impedance matched real splitting Network from Signal gen output parallel to both scopes. Other ways can not see any real data. But of course also this kind of simply test is useful.
Other thing is very big difference if we think how analog oscilloscope show noise what is "random" with scope eyes. This is real thing what have discussed and studied in many places. Owon itself can show much more noise than this Tektronix. It can proof if you look some signal sou´rce what produce some known signal added with some random noise peaks.
Fact, I believe, is of course that this noise in this case is coming from Owon.
Btw, for trigger stability there is adjustment in Owon trigger settings. (HF reject)
---------
About noise displaying with digital scope or analog scope.
(this is partially for these peoples who do not know and randomly read this topic and look these pictures where Tek analog scope do not show nearly any noise (or only small amount) and Owon screen is full of noise.
Try with 5ns width pulses with 10ms period. What you can see on Tek275 display and what can see on the Owon display?
On the Tek display nearly nothing or nothing and Owon show just clean full pulse without any problem. Same for noise, depending noise characters and what signal is trigged.
rf-loop I aggree with what you say. Btw the short BNC cables I used have exactly 53pF.
With my set up I do not want to make an exact measurement of noise levels and spectrum but just proove that it is perhaps the best way to get rid of the noise entirely. As I already said in an earlier post I'm not interested in qualifying something I do not want.
Once more, it's the amount of reduction that can be clearly seen in the pics that I consider a success. And as the connections are not altered between the Owon in and out of the oil can this reduction must be real.
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I do not know exactly how you have connected Owon+Tek parallel to signal generator but I believe this connection add much more than just pure 20pF Tek input capacitance. So, this connection may reduce much more bandwidth than may expect if think only Tek input 20pF. You can try. Connect fast edge instead of this sinewave and yoy can see high reduction in risetime, and this Network may also peaking with several frequencies die to its possible impedance mismatching.
Just for clariy. If connect 50ohm cable to 1MOhm input and look 50ohm cable free end. There is this cable cpacitance and inductance "Network".
Also I note that you use 2mV/dif in Owon. There is 20MHz BW limit. This noise frequency components have lot of over 20MHz frequency components what are now highly attenuaated and peaks are much lower than they really are.
If you want see around same with Tek oscilloscope and Owon ypu need do impedance matched real splitting Network from Signal gen output parallel to both scopes. Other ways can not see any real data. But of course also this kind of simply test is useful.
Other thing is very big difference if we think how analog oscilloscope show noise what is "random" with scope eyes. This is real thing what have discussed and studied in many places. Owon itself can show much more noise than this Tektronix. It can proof if you look some signal sou´rce what produce some known signal added with some random noise peaks.
Fact, I believe, is of course that this noise in this case is coming from Owon.
Btw, for trigger stability there is adjustment in Owon trigger settings. (HF reject)
---------
About noise displaying with digital scope or analog scope.
(this is partially for these peoples who do not know and randomly read this topic and look these pictures where Tek analog scope do not show nearly any noise (or only small amount) and Owon screen is full of noise.
Try with 5ns width pulses with 10ms period. What you can see on Tek275 display and what can see on the Owon display?
On the Tek display nearly nothing or nothing and Owon show just clean full pulse without any problem. Same for noise, depending noise characters and what signal is trigged.
rf-loop I aggree with what you say. Btw the short BNC cables I used have exactly 53pF.
With my set up I do not want to make an exact measurement of noise levels and spectrum but just proove that it is perhaps the best way to get rid of the noise entirely. As I already said in an earlier post I'm not interested in qualifying something I do not want.
Once more, it's the amount of reduction that can be clearly seen in the pics that I consider a success. And as the connections are not altered between the Owon in and out of the oil can this reduction must be real.
Yes and my opinion was and is
1: Of course "oil can" reduct this noise, there is no any doubt. Faraday box (well made) have worked in history and it works also today, as long as it is made ok.
Sidenote: Totally different case is example some "RF-shield" boxes installed example on the PCB what really are not faraday boxes due to fact they are in many cases more or less part of circuit (example multi point connection to GND where is RF currents and so, also every single point in GND area is different) And here comes also fact that Owon many SMPS circuits are designed without enough experience and knowledge about these things. This whole GND "Network" is just as "the magpie's nest". If they design just new and good layout for PCB's they can reduct lot of noise but it need really know what is doing. Of course it also need that every single SMPS circuit out RF is blocked. But also, what they have forget is that SMPS circuit input side is just as important as output side. To common wide area GND from single SMPS circuit internal GND is accepted only and alone DC current flow. It can stay on the PCB and it do not transfer its its internal noise to traawel all around. If designer do not know how to isolate these just By 2-5 components and right component selections and quite simple rules in PCB layout design it is better to pay final salary and kick out to play Mahjong on the street.
2: Previously and now: " I believe, this noise in this case is coming from Owon. "
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Yes, all correct!
This 'GND' network was also the reason to do the cage-of-Faraday-oil-can-test to see if there is a way to leave every thing just as it is (but they also must have achieved defenitely some improvements in their SMPS design as the new SDS9302 is notably less noisy) and just cage it so that nothing or very little of this noise is to be seen anymore from the outside world.
You know it as well when looking at the adapter PCB, all output currents of those little switchers - or at least significant part of it - are forced to go through the Z-plane....
When I had my first SDS working in 'exploded view' with my self build extender and power GND connections done with wires directly to the main PCB there was much lesser noise on the Z-plane and almost no differences anymore (you also mentioned that in one of your past posts as well, that when moving around with the probe tip every two points (GND lead / probe tip) showed different noise level.)
Yesterday I cut a window into my oil can for to see the reduction through the shielding directly on Owons screen and not have to use the Tek 475 anymore to see that.
And the pulse bursts also present in Owons noise 'melange' where back - I think you know what I mean.
So now I know that the display is not only a near field radiator as TomC calls it but also contributes significantly to the noise that's forced out of the BNCs on the other end.
Checked right away what's there of todays technology and found transparant and conducting film from various manufacterors that is also offered for EMI shielding, especially for displays of course (but also used to make solar cells).
Last to say is that I started to cover the window again but with a wire grid but could not finish it yesterday. So today will see further....
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Hi TomC + rf-loop,
I'm preparing the pics of the oil can test part 2 (without the 475) but not through yet - perhaps later...
In between found somthing that might be interesting to read:
http://www.lowemfoffice.com/low_emf_computer_display.htm (http://www.lowemfoffice.com/low_emf_computer_display.htm)
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Hi TomC and rf-loop,
so here is my first set of pics of the new Owon (Adapter PCB v3.3) without the oil can.
Opposite to my first impression there is still a lot of noise, but it's different from what I remember from my first Owon. The constant noise is much less now but there is noise 'flying by' that I haven't seen before and I think it is generated by the display and/or it's drivers. They changed the display power design slightly. Now there are no wire leads for the backlight anymore. It is supplied now through the ribbon as well. And they omitted one ground post of the adapter PCB close to the ribbon connector. I haven't checked further yet for other changes. The main PCB is the same version but with a National Semiconductor ADC (ADC 08D1500) which is probably the same as the TI one.
It took several hundreds of shots to catch all kinds of noise present bcause some of it is 'flying by' just occasionally - the bursts and the cloud like one. The spikes are more frequent.
I did shots in 2mV and 5mV sensitivity each with the SG505 output on and off.
Next I will post pics taken with the same settings but with the Owon inside the oil can in which I cut a window covered then with a wire grid.
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...and here the pics of the test with the oil can shield:
Btw, I did all pics at 2mV and 5mV because rf-loop said that the BW limit at 2mV causes lesser noise to be seen. There is a difference as the pics show but far not as much as one would expect. That is I think because of the gain/bandwidth product of the gain stage(s) in the preamp.
The last two pics show the difference with the cores on the power cord removed. That gives an idea of the quality of the line filter in the Owon SMPS....
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Yeah guys (TomC, hope some time you will say something again but anyways, I will post my results for everybody who's interested in.),
...and here are two pics I did after replacing the original input shield of my second SDS 9302 with the one I have made for my first SDS 9302. The Test set up is as in my post above using the oil can shield (Was very hard work removing the input shield from the old main PCB without killing it entirely).
What you see here is the only noise left. There are no bursts and no cloud like noise clusters anymore, so I post only this two pics with the SG505 output off and on and SDS 9302's input at 2mV.
Thanks God the noise that has disapeared now and of which I thought that it might come from the display is very likely generated by the digital circuitry of the main PCB - most of it I think from the ADC - and so can be and obviously is shielded off pretty well now.
(For to see my design of a new input shield check my post on 167:
https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/2490/ (https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/2490/))
Next I will remove all power supply return current from the Z-plane. That means to isolate the main SMPS and the adapter PCB groundwise (the mounting posts!) and then connect them by strong wires to each other and further to the main PCB. Also the upper two posts connecting the main PCB to the Z-plane will be replaced by plasic types. The Z-plane then will become part of an internal cage of Faraday and will be connected to the whole circuit only through the two posts close to the input BNCs.
Will post the results then.
Btw, got a new main PCB for my first SDS9302 from Owon through my dealer for 440 Euros, also equipped with the NS/TI ADC. Perhaps Owon now preferes the ADC08D1500 and stopped using the MXT2815 because of performance/reliability reasons. I do not think that NS/TI's price is lower then the Chinese made one, but maybe its also because of availability reasons.
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Hi Sarasir,
The latest noise results look great! :-+
Sorry if you felt ignored but I didn't have much to add to the last two sets of pics, just more noise on one set and less noise on the other. I'm glad you were able to reduce it with better input stage shielding.
It seems you have a clear picture of what you want to do next, so I'll wait for the next installment of results. :)
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Hi sarasir.
Nice result after your extremely hard work.
But I will (agen) nopte that you use 2mV/div ehere analog front end is 20MHz limited. Lot of SMPS circuits noise is around 50MHz to 200MHz. For this kind of noise 2mV setting risetime is not enough for show full peak levels) Only where is full BW is front end final stage and ADC input of course.
Perhaps Owon now preferes the ADC08D1500 and stopped using the MXT2815 because of performance/reliability reasons. I do not think that NS/TI's price is lower then the Chinese made one, but maybe its also because of availability reasons.
What is probkem with RuiFeng reliability? Perfomance is open question.. there NS/TI win more or less.
Chines (not specified) Company may destroy what ever IC reliability just simply By using wrong assembly methods and wrong PCB topology design (and wrong circuit design - some times they forget to read (and underrstand) data sheets and addendum informations) One example is how they forget data sheets recommendations is how they arrange GND's. (example separate AGND and DGND) Some may think that GND is same after 2mm trace. Yes it is for DC and only for DC.
I do not know MXT2815 situation today but some time ago Owon stop using some RuiFeng ADC versions in some models and surprise it happend after Rigol start massive use of RuiFeng ADC's. This may explain some things. Who knows... ;)
You have made interenting experimental work.
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Hi TomC and rf-loop,
Im very glad that there's no bad feelings left. Thank's a lot for understanding. Just want to add that when struggling for solutions and truth mostly there is also friction, inside of oneself and also in between partners and collegues. I consider this even as a natural and also healthy part of the whole process. Bringing in the whole of you including all your knowledge, doubts and emotions is in my view best prerequisite to achieve the max...
And I agree what rf-loop says but also already mentioned that the difference in between 2mV/5mV test results is not as big as one would think (partly gain/bandwith product I guess, but didn't give it hard thinking yet). As you can see above (oil can test 1+2) all types of noise was present in both 2 and 5mV, with some differencies of course but just little . Also what to consider is that BW Limit @ 20MHz does not mean that the frequency response stops there immediately.
And further thinking about brings up the question at what point is certain kind of the noise - now shielded off by the input shield - introduced into the chain. Before the BF filter or after?
...and to be honest, I was just to lazy - and also very hungry - yesterday to take the SDS out of the oil can again, switch to 5mV and put it back in what also includes everytime removing the cores, the BNC coupling, and the lid and putting all back on... and still wanted to post the result right away.
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Hi TomC and rf-loop,
as I disasembled my first test approach which was to externalize all switchers (now it looks quite rediculous to me that I thought it might really work) few days ago to get my first SDS 9202 together and working again I started thinking about how to denoise this switchers the best way. You know my first try was adding lots of tantalums and coils what actually spoiled the power up and down rules and also created overshoots and ringing which Im pretty sure now killed the ADC. I read the data sheet from NS/TI and found another restriction (in addition to the over/undervoltage restriction) which is that the supply voltage of the circuit feeding the input must go down first and then ADC's supply. Doing it vice versa also could kill the beast.
And by reading papers about denoising and about ESR of different types of capacitors, I had to realize that tantalums - even chip types - are absolutely out today in this aspect (how easy was it in the old days when just a few tantalum beads did the job....)
I feel ashamed because of my ignorance, and lazyness by using this old components but this little ceramic chips are always a challenge to me to solder especially with my old eyes.
Only on the backlight switcher I had already used a chain of ceramic C chips because there is this restriction of 10uF max at the output.
So, anyways for three days now I've been sorting out my stock of ceramic SMDs - thanks god I have this little Wavetek LRC meter which is a very handy thing - but still it's something else especially if you had put mountains of all kinds of PCBs on the oven last year and heated them up and just drew off all SMDs - boxes full of SMDs I have, I tell you but, thanks God have done some preliminary sorting already in the past.
And immediately I did some preliminary testing:
My simple idea is why not replacing a 10uF ceramic chip - as it is used by Owon as a standart on most switchers in paralell with a smaller 1uF chip and another even smaller one - e.g. with 10 x 1uF chips to push down the ESR? And, as I expected of course it works pretty well so far.
I used the Tek SG503 (up to 260MHz constant amplitude sine wave generator) and alternately the Tek PG506 (50 Mhz suare wave generator) and of course my 475A 250Mhz analog scope.
Used a little piece of tin sheet and BNC cable + 50 Ohm ternination + BNC connector soldered to the sheet on one side and another BNC connector and probe adapter and 10 x probe on the other side to the scope. In between I soldered different chips to the groung plane (tin sheet) and a wire across connecting all together.
The task now is to find out the best chip combination inside of the limit that is given by the original capacitance amount with the maximum attenuation of the HF.
And my question to you is, do you have any experience made in this already?
Remarkably is that I haven't seen this, as it looks to me, simple trick in any paper I have browsed through yet dealing with denoising. Of course Owons approach is to be found - e.g. three different sized chips in paralell - but not more. Maybe it's because of economical reasons but if you look at the low price of this capacitor chips in mass production I can not really see this.
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Hi Sarasir,
Personally I didn't use this approach on my SDS7102, however, many of our members used smaller capacitors to more successfully shunt the higher frequencies. I don't remember seeing more than 3 capacitors in parallel and don't know if using more may significantly improve the situation, maybe your experiment will answer this. At the time, I think the main thrust was to identify places on the circuit where these capacitors may be of benefit as well as existing locations on the board where they could be installed without or with the least amount of modifications to the existing circuit board traces.
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Hi TomC,
with the SG 503 generator at max output level and frequency (3.5V P-P / 270 MHz displayed by the 475A at the 50 Ohm termination and no connection to the capacitors) and the 475A with 10x probe and at max sensitivity (5mV with 10x probe = 50mV):
Testing the Owon standart 10uF + 1uF + 100nF (decending chip size 3.2mm/2mm/1.5mm) will give a residual level of 150mV.
Using 10 x 1uF of 2mm size instead the level goes down to 70 mV.
So it is not so much compared to the efford and I think that it is some kind of a zero sequence (Math) which means that it will go towards zero more and more by adding more and more capacitors but never will reach zero actually.
But by adding just a little ferrite bead (two holes) in front and another 100nF/1.5mm to the Owon standart the level went down from 150mv to 15mV.
The level using 10 x 1uF and the ferrite bead went down to 10mV.
Adding another 1uF to the Owon standart + 100nf + bead the level went down to < 10mv, so that's it in a way - so far!.
The guys where right (what you said above)! Just wonder why Owon does not use ferrite beads.
Added later:
It just came to my mind that I tested without DC running through the bead, so with up to 1A it will certainly look different!
The thing with the mechanical arrangement is very critical in deed. The connection must be absolutely straight forward what means the connecting wire must go precisely from one C to the next C and no short cuts at all allowed just all arranged in a straight line. Connecting the out wire just little - e.g. 3mm - before the end of the chain will raise the level right away remarkably - almost double or so.
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Hi Sarasir,
Interesting experiment!
As I see it, the interaction of the mechanical arrangement is consistent with the theory behind the use of smaller capacitors for high frequency filtering since longer leads increase the inductance which is precisely what smaller capacitors reduce.
I also think the ferrite bead will still be effective with a DC bias, specially since the two hole configuration you are using seems to be common mode which should result in a null field for the DC bias current with little chance of saturation.
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Hi to all.
I read the thread occasionally and I haven't understand which is the area of the scope at the Sarasir mod. Is there any photo?
By the way, Owon upload a new fw with 1st August of date for SDS71021312xxx, SDS71021319xxx, SDS71021327xxx, SDS71021334xxx, SDS71021344xxx, SDS71021352xxx
and
SDS71021407xxx, SDS71021414xxx, SDS71021418xxx series.
Same changing log with previous update (May), but for some reason split these series at the firmware.
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Hi lemon,
Nice to hear from you again!
I'll try to summarize what Sarasir has been doing until he has a chance to answer your post himself:
In general there has been a number of experiments trying to come up with new ways of eliminating the ground noise on his SDS9302s. The early experiments involved removing the DC-DC switchers from the Owon boards, adding filtering & shielding, and reconnecting them via long cables. This approach has now been abandoned because of complications caused by the long cables.
During this time he also modified the shield for the scope's input section
https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/2490/ (https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/2490/))
These mods successfully improved the noise situation and were later added to his second SDS9302.
The next experiment involved the use of a Faraday cage implemented with an oil can to see its effect on the ground noise. Later a window to view the scope's screen was added to the Faraday cage. Both experiments showed noise reduction, I'm not sure if a permanent mod is planned based on these experiments.
The latest experiments involve testing different combinations of small capacitors and ferrite beads for their ability to filter the output of a high frequency signal generator. The intent is to use the best performing combinations as filters for the DC-DC switchers.
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Hi lemon,
Nice to hear from you again!
I'll try to summarize what Sarasir has been doing until he has a chance to answer your post himself:
Thanks TomC, it is very kind from you. I appreciate it a much.
In general there has been a number of experiments trying to come up with new ways of eliminating the ground noise on his SDS9302s. The early experiments involved removing the DC-DC switchers from the Owon boards, adding filtering & shielding, and reconnecting them via long cables. This approach has now been abandoned because of complications caused by the long cables.
Something like that doing a Russian member (BAHHAOO or like this) before (do you remember, he has very well improvement). Very effective approach but difficult cause the demand of redesign all the power boards.
During this time he also modified the shield for the scope's input section
https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/2490/ (https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/2490/))
These mods successfully improved the noise situation and were later added to his second SDS9302.
I saw it and likes me...
The next experiment involved the use of a Faraday cage implemented with an oil can to see its effect on the ground noise. Later a window to view the scope's screen was added to the Faraday cage. Both experiments showed noise reduction, I'm not sure if a permanent mod is planned based on these experiments.
The Faraday cage was for PSU Board, something like I was make before or the Faraday cage was for the probes?
The latest experiments involve testing different combinations of small capacitors and ferrite beads for their ability to filter the output of a high frequency signal generator. The intent is to use the best performing combinations as filters for the DC-DC switchers.
I supposed that this mod is for adapter board, isn't it? I read the last two pages but I can't find for what dc-dc switchers, he was refereed?
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Hi lemmon,
thanks a lot TomC for summarizing my attemts - great!
another reason for to abandon the removal of all switchers from the scope, cleaning their DC outputs and connecting them back to the scope using long cables was that this experiment showed that there is also a lot of noise generated by the digital circiutry on the Main PCB itself.
And by using long cables with additional filtering the power up and down sequencies where disturbed along with ringing caused by e.g. the ADC switching from low power mode to normal operation (haven't mentioned that yet actually I think). That load change caused spikes on the DC power lines that together with a wrong DC voltages power on/off timing killed the ADC on my first SDS 9302.
Next idea was the Oil Can test as a consequence of pictures and inside views gained through profound and extended discussions with TomC and also rf-loop who threw in his knowledge time and again:
The Faraday cage experiment was to put the whole SDS into an old oil can and connecting the can only to the input BNCs so to catch up all emissions radiated by the SDS and feed them back to the input ground side - in a way nulling them out - thus eliminating their impact on anything that is connected to the input.
That worked to a certain extend quite well but also showed that there must be another leak through which noise is coupled to the input. And that was the poor input shielding.
(I already noted that before and had redesigned it concurrently with the switcher removal - thanks God - but it was on the broken PCB so had to work it over to the new one!!! - read below!)
And, to continue, it's not the original shield actually but it is the way it is connected to the main PCB. By soldering it to the PCB on only three or four points as is was on my 1st and 2nd SDS (upper shield I think three and lower shield four soldering points, on 1st SDS just three points on both I think!) the shields could not work properly for RF only for LF it was perfect.
(Remember just a few millimeters make a big difference in the e.g. 100 to 300 MHz range - not to talk about the area above!).
Everybody who wants to fix this might just solder the existing shields all around seemlessly to the PCB (watch the white areas where the PCB tracks pass under the shield and do not attemt to solder there!) and - also very importand - add some circular spring - look at my photos - to connect the BNC connectors directly to the shield - not as originally only to the PCB (that I think is also very important for a maximum input shielding improvment)
The negative aspect of this is that whenever some repair is needed inside the shields access is quite difficult. I would mean to remove the shields and whoever has already done somethig like that knows what I'm talking about. Only this is why I redesigned the shields, build a frame and screwed the original shields to it on top - just to sustain accsess to the inside.
And the filtering test with beads added is for all switchers. Mainly on the adapter PCB but also on PSU PCB and perhaps also the 1.9V switcher on the main PCB (needs checking if really necessary for not to kill another ADC).
All very complex because of it's caotic nature and it takes a lot of thinking to gain a clear view of all interactions and to find the right keys....
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... and after thinking a while about all and reading again I want to add, yes of course I will try to come up with an over all modification to free the SDSs from noise as much as possible with reasonable efford.
There is one thing left and the oil can test result has lead me to that and that is the role the z-plane acts in this drama.
Thinking after the oil can/Faraday cage test results where present about how to realize an internal cage I focused on the z-plane as it is the biggest metal inside and therefore certainly must be somehow included in that or actually should even be the base of an internal Faraday cage.
And suddenly I became aware of what role this z-plane has been given by this Owon engineers in their naive thinking:
They use it to transport the return currents of all switchers. Wow!!!! I thought, that might be the Gordian Knot we have looked at all the time but could not cut it because we didn't recognize it.
(I' talking only about the time since I've joined here - posts before I read a lot but still not all yet)
In other words, we where speaking of radiation, emission, antennas, noise and spikes but we never focused on what the biggest part of this noise radiating antenna actually is.
It is the z-plane, and it is because the Owon engineers have forced it into that role by making it conducting/transporting all that strong, noisy and chaotic return currents.
The thing MUST radiate like hell - no other choice.
So, the next and hopfully final test is to free this z-plane from all return currents and by this making it a true shield that is only connected to the most sensitive point that we want to be clean, the input BNCs. And I'm looking forward to the result with great tension, because I have a certain feeling that this might be the hidden key we where searching for such a long time....
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Sarasir, thanks for the clarification and explaination for what you have done until now!
Now, I have clearly all of them in my mind...
The Z-plate and how this related with the noise, had a lot of conversation before (older messages).
rf-loop many times has referred about this.
I don't think so that the Owon uses the z-plate for better returned currents of switchers.
I think that in their mind, was the better shielding.
Your thought to remove all the returned currents from z-plane, will be the better solution for the "noise-free" of this scope.
I had made a lot of modification on adapter board (like rf-loop did) and some more to the backlight circuit.
When I attached the new psu & adapter board that Owon warranty cover to me, I have stopped any modification to this board.
With the new noise level I am been satisfied, but I can to experiment with the olders boards...
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Hi lemon,
The Z-plate and how this related with the noise, had a lot of conversation before (older messages).
rf-loop many times has referred about this.
I don't think so that the Owon uses the z-plate for better returned currents of switchers.
I think that in their mind, was the better shielding.
yes, I know, rf-loop said as well that there is differential noise everywhere on the z-plane.
But nobody so far has seen it as a result of return current RF voltage drops yet (to my knowledge), rather as coupled through the electrical and magnetical fields to the z-plane from adapter PCB. That in my opinion is a very important difference.
If the return currents go through the Z-plane there will be RF voltage drops due to inductivities of the z-plane resulting in different noise potentials all around the z-plane especially in the area around the big aperture where main PCB and adapter PCB are connected. That is almost like if you want to use it as antenna of a transmitter. I can not understand how they could think of the z-plane as a shield when the same time it functions almost as a dipole antenna or - I'm not too familiar with antenna technology - or as the feeding element of a multi-element-antenna.
Replacing z-plane as a conductor by wires should reduce radiation tremendously as the area that is radiating is reduced significantly. And if that is not enough these wires could also be shielded.
In former discussions with TomC you can see how we arrived at the picture, seeing the whole problem as a RF-frequencies-radiation-balancing-thing - just if you didn't get that yet entirely.
I'm working on my first SDS to get it running again - got a new main PCB - and will do the modification then on it. Will take a while...
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Hi!
I am considering purchasing this scope and have read all of the available manuals etc. but I had a couple of questions that were not answered by reading the manual.
1) Does this scope have a waveform averaging function? If so, what is the range of samples that it can take?
2) For the FFT function, what is the range of points that can be selected?
3) Can this scope perform an FFT on a portion of the displayed waveform?
Thanks for all of your help!
OldTimer
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Hi!
I am considering purchasing this scope and have read all of the available manuals etc. but I had a couple of questions that were not answered by reading the manual.
1) Does this scope have a waveform averaging function? If so, what is the range of samples that it can take?
2) For the FFT function, what is the range of points that can be selected?
3) Can this scope perform an FFT on a portion of the displayed waveform?
Thanks for all of your help!
OldTimer
1. Yes it have.
In User manual:
ACQU MODE Menu
Average: 4, 16, 64, 128
2.
In User manual:
FFT function in this oscilloscope transforms 2048 data points of the time-domain (YT) signal into its frequency components mathematically and the final frequency contains 1024 points ranging from 0Hz to Nyquist frequency.
3. If you mean that is it possible to user select portion (example with cursors or other way) of YT trace for FFT: Not possible. (Of course it is possible externally if take sampled waveform to computer and use what ever FFT analyzing software.)
Scope use always 2048 data points for produce FFT. (user can not select this) And in FFT operation YT display is not available. (not windowed YT / FFT display)
Also here something about Owon FFT
http://owon.freeforums.org/some-tests-with-fft-t8.html (http://owon.freeforums.org/some-tests-with-fft-t8.html)
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Hi!
I am considering purchasing this scope and have read all of the available manuals etc. but I had a couple of questions that were not answered by reading the manual.
1) Does this scope have a waveform averaging function? If so, what is the range of samples that it can take?
2) For the FFT function, what is the range of points that can be selected?
3) Can this scope perform an FFT on a portion of the displayed waveform?
Thanks for all of your help!
OldTimer
1. Yes it have.
In User manual:
ACQU MODE Menu
Average: 4, 16, 64, 128
2.
In User manual:
FFT function in this oscilloscope transforms 2048 data points of the time-domain (YT) signal into its frequency components mathematically and the final frequency contains 1024 points ranging from 0Hz to Nyquist frequency.
3. If you mean that is it possible to user select portion (example with cursors or other way) of YT trace for FFT: Not possible. (Of course it is possible externally if take sampled waveform to computer and use what ever FFT analyzing software.)
Scope use always 2048 data points for produce FFT. (user can not select this) And in FFT operation YT display is not available. (not windowed YT / FFT display)
Also here something about Owon FFT
http://owon.freeforums.org/some-tests-with-fft-t8.html (http://owon.freeforums.org/some-tests-with-fft-t8.html)
Thanks!
1) Thanks for translating that item from their "marketing phrase" in the manual. I missed that.
2) Yes, I had seen that in the manual but I was wondering if any alternate size was available for the FFT. Obviously not. :(
3) This is what I currently need to do with my current DSO and it is a real pain, so I was HOPING that might available on the scope.
On another note, how easy is it to transfer data from the scope to a computer (so as to make #3 tolerable)?
Thanks again for all of your help!
OldTimer
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Hello everyone. I have trouble ... Tribrach ceased to function (does not lock signal). Help me. Give details of their devices. With chips:
BU2506FV (pin 19,18,11,10,1) and LMH6574 (pin 13,12,1,3,5,7,6,14). If not difficult to measure without a stylus all the settings to zero. And the settings on the test tone (1 kHz 5v). Thanks in advance.
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Hello everyone. I have trouble ... Tribrach ceased to function (does not lock signal). Help me. Give details of their devices. With chips:
BU2506FV (pin 19,18,11,10,1) and LMH6574 (pin 13,12,1,3,5,7,6,14). If not difficult to measure without a stylus all the settings to zero. And the settings on the test tone (1 kHz 5v). Thanks in advance.
Hi BBAAHHOO,
I imagine this is some kind of photographic equipment that attaches to the tripod. Don't have any idea myself of how it works or how to repair it, sorry!
You may want to also try posting a new thread on the repair section:
https://www.eevblog.com/forum/repair/ (https://www.eevblog.com/forum/repair/)
It's possible that some members that frequent that section may have some experience with this! :)
Try posting as many details as you can!
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Hello everybody
i got a new SDS 7102V
The SDS show me the FW Nr is 3.5
On the homepage of Owon in China I can see that there is an update available.
My Serialn ist SDS 7102V1414xxx
Can you help me to make a decision if it is good to update my new unit?
What is the latest update Version Nr?
And are they many difference between my FW 3.5 Version and the latest available FW Version?
many thanks in advance
greetings from austria
hansi
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hi hansi,
Your scope is very new and according to Owon doesn't need an upgrade. You can check this out here by entering your model and serial:
http://www.owon.com.hk/main.asp (http://www.owon.com.hk/main.asp)
If you don't enter your serial there is an upgrade listed that applies to your scope, however, if you install it you'll probably won't see any difference in performance because according to Owon you already have it. The number of the latest firmware release is not the same for all SDS7102s, it depends on the serial number.
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As to OWON products, I have something to mention, if you are in USA, better by from local distributor such as www.saelig.com (http://www.saelig.com), because, if you buy from ebay or Amazon, they don't take care of your after sales service, if the scope failed, the seller on ebay or amazon will ask you send back to China for repair, that is really upset.
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It is a pity that you can not help me ... :( :-BROKE
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dear tomc
many thanks for your fast answer.
I am very happy with the scope
greetings
hansi
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It is a pity that you can not help me ... :( :-BROKE
I don't understand what is your question! What is the "Tribrach" and how this related with the Owon SDS7102?
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Trigger - Capture signal amplitude level .... I hope somebody metering signals on a chip, and lay them to find my fault.
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I had bricked my scope in a failed firmware update. My scope was purchased from an Ebay seller. Saelig provided me with files to recover from the failure, and I now have a working scope with the latest firmware for my serial number.
As to OWON products, I have something to mention, if you are in USA, better by from local distributor such as www.saelig.com (http://www.saelig.com), because, if you buy from ebay or Amazon, they don't take care of your after sales service, if the scope failed, the seller on ebay or amazon will ask you send back to China for repair, that is really upset.
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@BBAAHHOO = Now, I see what you said...unfortunately, I haven't this time the unit open.
@radhaz = Can you provide us these files via an up-loader internet area?
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Hi TomC, rf-loop, lemon and whoever's interested,
last weeks I dug into denoising these switchers and finally I'm able to come up with a new 'installment' to use TomC's expression.
I would call this,
(and please get me clear in that I use upper case further down only to indicate a headline - not shouting even though I would like to shout a bit at all this professional designers of and writers about how to denoise SMPSs! But you never know. Certainly not all of them because I read somwhere on a page of a supplier of sealed and small converters that his ones are free of noise and well suited to supply sensitive circuitry. So I knew in front of my experiments that such thing must be able to be designed somehow. And not to mention all those books on amazon and ebay - and believe me I didn't search for them but these advertisement algorithms became quite advanced nowadays, almost mystical - about SMPSs at prices I thought, wow! there must be lots of fine information - quite above 100$/€ many of them - bu didn't buy one of them.)
so here it is:
HOW TO DENOISE A SWITCHING DC-DC CONVERTER PROPERLY
-------------------------------------------------------------------------------
Once you know how to do it it's quite easy but it took me a while and a few redesigns of my prototype to find out.
Please understand that I didn't document all stages I went through including the performance of the original circuit on OWON's adapter PCB. I think that everybody who's got aware of these problems should be able to understand everything from what I post and write. It' just a lot of work to take and prepare the pics and it took me many days.
Setting out from my capacitors test tounament - TomC you certainly remember - I thought that that should give the basic idea how to denoise these converters.
So I designed a little PCB also with much better layout than OWON's design for to generate as little as possible spikes in the circuit itself according to some ideas given in the papers I found on the web and also got from you here (TomC, thanks again).
And when testing found again these unpleasing spikes on my Tek 475A.
So went into further thinking. What I had done was, as my capacitor tournament showed, to arrange several ceramics beginning with 10/20uF 3.2mm going down to 100nF 1.5mm on input and output all connected in a straight chain - no shortcuts - and in between a ferrite bead.
The failure in my design was that I used a too wide ground area in between the circuit and the outside (in-/output). That there should be only one ground connection between the switcher and the outside was clear to me before (and no vias at all inside the circuit) but not that there must not be any space in between the opposite filter Cs also on the ground side.
So I redesigned my PCB and finally arrived at the trick:
That is that the ground run must be also as thin as possible almost like the positive in/out lines!
I would call this 'Straight Line Back To Back' Design!
What it means is to arrange the in/out filter capacitors not only in a straight line but also back to back one after the other and pretty symetrical.
With a broad ground connection and the filter Cs on both sides HF currents would build up inside the ground area making it only possible to denoise either the input or the output but never both of them at the same time.
And as you can see on the pics below it worked.
So again in one sentence:
There should be only one quite narrow ground connection to and from a switcher (in one line!) with it's filter Cs arranged straight down/up this line symetrically just as the hot lines should connect the other sides of the Cs one after the other also by thin tracks.
And It didn't need any beads anymore they are actually useless in this configuration and don't work much anyways. The two toroids I used on the in- and output are for to filter out remainders of the switching frequency itself and even more also the remainding regulator loop's feedback oscillation, not the spikes and the HF ringing.
I used two 100nF ceramics as a final HF killer after the toroids and soldered them directly to the back of the BNC connector and again there where little spikes to be seen. Only after i moved them close together on one side of the BNC ground sleeve also these spikes where gone.
So the whole design has conducted me to the understanding that expresses itself best through the fact that even a BNC connector will not be free of internal HF voltage drops as long as you do not connect it the right way!
And we almost could have known before only, that even on the ground plane just a few millimeters count so much was not really clear to me - thanks a lot rf-loop for pointing in that direction time and again.
(And be aware that there is a big difference in between conducting metal and shielding metal. Conducting metal causes HF radiation due to the voltage drops of the conducted HF in accordance with the in the metal inherent complex resistances, whereas the only shielding metal reduces radiation. Still to think about further why exactly...)
And btw I used a tantalum chip also at the output after the toroid as it performed marginally better concerning inherent noise what means - an I haven't examined that closer yet - that I guess that these very dense ceramic Cs - e.g. 10uF 3.2mm - create also some kind of broadband noise inside - not very high up rather below HF. You can see that kind of noise on the output screen shots as it is the same with both capacitor types only the tantalum seems a bit lower.
The tantalum at the input is just a replacement fot the 220uF reservoir C on the original adapter PCB.
And I have used double sided epoxy for my little PCB and the lower side is connected to ground only at the BNC connector.
(Some basic ideas to this where also influenced somehow by my oil-can test you probably remember?)
So to make a long story short here are the pics and hopefuly I haven't forgotten anything important but I'm sure and also thankful in advance that you would tell me if so.
Just take the file names please for description so far.
And not to forget also to write it down, there is neither HF noise nor spikes anymore on the in- and output of the redesigned +3.3V buck converter.
(And finally I do call out to far China: PLEASE, OWON ENGINEERS , CHECK THIS!!!!!)
PS.:
...and I forgot to mention that these two schottky diodes across the output toroid are there for keeping the over-/undershoot caused by the toroid during power up under +- 100mv...
...and of course I connected the switcher directly to the scope using a BNC mail coupling for to have maximum sensitivity and bandwidth and not to have to use any probe for the noise measurement itself...
....and the probe hook you can see on the setup pics close to the PCB is for to pick up spikes radiated by the converter capacitivly - distance about 2-3cm for coupling capacitance far below one picofarad - and to use these via CHII as the trigger signal...
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Hi sarasir,
Excellent results! :-+
After reading your post I think I have a pretty good idea of how you configured the components and how you conducted the tests. It's clear to me that the differential mode noise at the output of the switcher is nearly non-existent. There is one more test I would do if you haven't already done it. Instead of connecting to the scope directly at the BNC, I would use a probe with a long ground lead to connect to the switcher's output. This is a cheap but helpful way of purposely creating an impedance imbalance that would make common mode noise at the output of the switcher visible on the scope.
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Hi TomC,
thank you for checking. Yes, thats a good idea, only I would have to use a 10x probe then. A 1x probe here is disatrous (in contrast to the bandwith limit's impact of the OWON to the noise displayed which is not as heavy as one would expect - had that topic with rf-loop 2 times - probably you remember).
Even with a good Tek probe, at 1x the bandwidth goes down like a brick and consequently the displayed noise as well. It was this problem that actually made me hooking up the little switcher directly to the 475 scope's input.
But hold on I will use an active probe then. Normally try to avoid additional active components as much as possible in cases like this here because you never know what you get because there is another line, and that's the power supply of the active probe and sturation probs and whatever. But actually I think it should work.
I will do the test with both a 10X and an active 1x probe.
We'll see tomorrow. For today (actually tonight!) I'm done.
P.S.: And after thinking about your proposal for a while I can tell you right away what we will get tomorrow: To me it is absolutely clear that as long as even this little PCB radiates certain emissions - and you can see that through the probe hook I used to pick up the trigger signal capacitively - we will have common mode noise on the in-/outputs and therefore as well on the BNC connector (remember, the BNC is only for monitoring either the input or output with the scope). Not so much because I already used the lower plane of the little PCB as a shield, but it will be there. It's the same thing on a minor scale as it is with the whole Owon scope on a major scale.
Just as the whole scope had to be put into the oil can to eliminate common mode noise also this little switcher has to be put into a small faraday box connected only to the BNC ground side for to eliminate comon mode noise effectivly and totaly.
But as it is just a little PCB a piece of chopper foil wrapped around might do the job tomorrow.
Im really looking forward to it....
And now I'm defenitely ready for my bed!
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Hi TomC,
so here the Common Mode Test results. It should be mentioned for everybody else who's reading this that this is only empirical and no absolute numbers can be given with this setup. That is also what also many papers say how it has to be done more or less if switching DC-DC converters have to be denoised especialy since their working frequencies got quite high.
I tested both probe types, passive and active. To my surprise the Tek P 6062 is also only a x10 probe, but gave slightly higher levels probably due to its very low input capacitance (2pF) so I used it for the test.
Used the longest ground lead (16cm) I had for the P6062, and I hope that's long enough to give a 'proper' impedance imbalance.
On the pics you can see the results. They are as I expected. The screwdriver is held by a little vice and I used it for to give the emissions of the unshielded converter more drain which of course provoked higher common mode level in turn (The screwdriver has about 1cm distance to the components).
With the shielded converter I could not use the passive probe's hook I used with the differential mode test before to pick up the trigger signal capacitively. The moment I put it a little into a small hole in the shield I left open the spikes would come back. Of course I would say...
Without the shield I could use the internal trigger path of the 475 as the spikes level was just high enough. With the shield the time base run free and there was no way to get the 475 to trigger. By varying the time base variable slowly I would have seen had there been any spike hidden, but there was nothing to reveal.
Now after carring the picture of this HF (im-)balance mechanism - radiation on one side causes common mode noise on the other side and also vice versa!! (think about that, that connecting something conducting and massy to OWON's SDS input will make it even more radiating on the other side!) - quite a while in my head it became very familiar to me and your test proposal gave it a good push - I feel it now. Was actually first time now that I knew exctly the result before the actual test. I have learned so much from this problem.
In the past when I had to denoise something I used line filters, capacitors and coils but never really knew what I did and what will be the result. It worked often but had always too much magic for my longing for a logical approach I need to work effective and quick.
And last not least to mention that I used several cores on the power in wires to set the circuit as free as possible HF wise and also disconnected the voltmeter monitoring the output from the load resistor before I shot the pics.
-
...
P.S.: And after thinking about your proposal for a while I can tell you right away what we will get tomorrow: To me it is absolutely clear that as long as even this little PCB radiates certain emissions - and you can see that through the probe hook I used to pick up the trigger signal capacitively - we will have common mode noise on the in-/outputs and therefore as well on the BNC connector (remember, the BNC is only for monitoring either the input or output with the scope). Not so much because I already used the lower plane of the little PCB as a shield, but it will be there. It's the same thing on a minor scale as it is with the whole Owon scope on a major scale.
Just as the whole scope had to be put into the oil can to eliminate common mode noise also this little switcher has to be put into a small faraday box connected only to the BNC ground side for to eliminate comon mode noise effectivly and totaly.
...
Very nice job, Sarasir...very nice!
I am looking your results with very interesting!
Maybe, a small metal box with this circuit joined to the external trigger bnc will be fine!
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Yes, lemon,
thanks a lot! That's what I will do, of course, putting these switchers ino a metal box above the adapter PCB. That's how I started actually but just intuitively. Now I know better what to do in detail. Before I used fat coils and lots of capacitance with just medium results and soldered the components of the switchers to the inside of the tin boxes I used. Now I know better. They will go on a common PCB in a common tin box but with the switchers isolated from each other and each one just connected at it's ground point - see above first 'installment' about denoising - to the box. And the box will be connected to several ground points of the main PCB through wires. And the adapter PCB will be isolated from the z-plane...
And there are more things to think about: The main power supply with it's connection to the outside world, the mains outlet, and very important the display with its large area also facing the outside... and then there are the digital connectors...
But please lemon, tell me why do you suggest to connect the box to the external trigger input? Don't get it.
And TomC,
one more thought went through my head, just to mention it. Your long ground lead's function is the same as my cores on the power in line, just to decouple the HF. And of course it's an impedance imbalance but you could call it also a low pass filter...
Just something else to think about if there isn't anything better to do...
Possibly this post will go on forever...
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Hi Sarasir,
Thanks for performing this test, very interesting and the results are pretty clear in my mind! :-+
From what I see I would say that most of the noise you see on the unshielded and screwdriver test is due to near field and radiated RF picked up through the air as common mode noise by the impedance imbalance probe arrangement. This is why the shield is so effective in eliminating the noise and of course any intrusion like the antenna effect of the probe hook being introduced into the mix upsets it and allows radiation through the air again. There is no indication of conductive common mode noise getting past the filtering which is a good thing and qualifies the effectiveness of the multiple in line capacitor arrangement filter that you are using.
Again, very nice and interesting, keep it up! :)
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Hi TomC,
as you might have expected I have problems with your picture of the noise path. Can't see how it could work that way...
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Hi TomC,
as you might have expected I have problems with your picture of the noise path. Can't see how it could work that way...
Hi Sarasir,
Sorry that you don't agree with my picture of the noise path, frankly I just explained it as I see it, didn't really know or foresee what your reaction would be!
This is your experiment, and I'm just commenting as an onlooker, so please go ahead and tell us how you see it, maybe I'll learn something new, or maybe, like you, I won't be able to see how it could work that way. Either way other members will be exposed to different theories and some may even wish to contribute!
In any case, whether we agree or disagree on the mechanics of how or why things happen the way they do, I'm glad that you did these tests and clearly documented the results with words and pictures. So I want to sincerely thank you for the considerable time and effort that you graciously spent to make this information available to all of us!
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Hi TomC,
of course, I aggree with everything you say. I was just running out of time and also wanted to sleep it over yesterday for to get a clearer view of what you said.
And of course I gave it quite some thinking and will do another test and that is simply removing the improvised shield again from the little PCB - what I would have to do anyways - and instead of will wrap another and bigger and also grounded foil around the probe arrangement to exclude any direct radiation into it.
You see, - some thoughts right away in advance - the radiation field around the small PCB should look like a circular dome, more or less, because it's beeing attracted and deformed by any conducting existence around. (And to be precise, even non conducting matter through the individual dielectric properties should have a very slight influence.)
The probe arrangement I had hooked up goes straight away on the BNC side, also the ground lead straight away especially for not to pick up or to pick up as little as possible direct radiation. So if you imagine that picture you will see that just a little portion of the radiation dome - like a piece of a round cake you cut out - will be relevant at all to induce current which in turn together with the impedances of the arrangement will cause voltage drops then in the arrangement. Compared to the return path of the entire radiation dome which runs of course also through the probe arrangement, the by it received radiation should be very little and in addition even opposite in phase so rather would even reduce the measured level instead of increasing it (But that, due to the complex nature of the set up with numerous stray Cs + Ls and therefore pretty chaotic phase shifts everywhere changing ever millimeter is just theory).
So theoretically there might be even a slight increase in measured voltage after shielding the probe arrangement but only due to the then inhibited negative feedback maybe induced by this little portion received out of the radiated circular field dome.
More later as I have to work now....
But please in between tell me if you can see what I mean.
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...
But please lemon, tell me why do you suggest to connect the box to the external trigger input? Don't get it.
...
Sometimes, it is difficult to me to understand so big messages. My English aren't so good!
It was a simple suggestion of gnd position, as external device, that anyone can to remove easy!
From what I see, you think to make internal to various gnd points on main pcb.
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But please in between tell me if you can see what I mean.
Hi Sarasir,
I think your alternative explanation of the signal path during the unshielded test is plausible. However, in my mind, it somewhat conflicts with the results of the shielded test. Hopefully the additional test you proposed will shed more light into this. My feeling at the moment is that you'll see less noise with the probe arrangement shielded. But as we all know, things don't always turn out the way we imagine them, so will see!
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Hi lemon + TomC,
of course the denoised converters have to go back into the scope. The supply connection (plus and minus) to the main PCB should then be done with wires to free the z-plane from any conducting current. That is because clean DC at the output of the converters doesn't mean automatically that it will also be clean at the other end of any conducting media - either wires or z-plane. As the current draft of the main PCB is very noisy there will be noise as well one a conductor due to it's impedance and therefore unwanted HF radiation will take place again.
The wires if necessary can be even shielded but not the z-plane which in turn should actuall serve as part of an internal Cage of Faraday and therefore will be connected only to the input BNC's of course including the external trigger input.
TomC, I said that there might be even a bit more level if the probe arrangement will be shielded due to the blocked direct radiation to it. But I doubt that that will be noticeable as it is a very very small portion of the whole radiation that arrives there I guess.
But as you said, any prediction is difficult here.
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Hi TomC,
so here the resulte with the probe arrangement shielded.
The common mode noise is still there but a little less. I guess thats because the shield - a aluminum container for calcium tablets my hungarian girlfriend left years ago which I soldered (got me some aluminum solder flux recently - it's super!) to the Bottom of the little PCB - draws part of the radiation and closes the loop for this part before the probe arrangement. I forgot that in my prediction, that a nearby metal of course will 'catch' a certain amount of the emissions and as - once more - this metal is soldered to the common joint this part of the emissions does not exist for the 'outside world' anymore.
The screwdriver, again placed as in the test before, increases the noise level again as it also draws emissions but they are not fed back to the converter's ground directly but rather go 'into the air' (Finally they will of course also return but rather through me, through everything around that's conducting, the power cords, whatever, finally reaching the scope and the probe to close in the circle) So this draw increases the return current through the probe's ground lead which because of it's impedance that can only provide a poor HF connection between the probe's sleeve and the ground connection at the switcher's BNC, and consequently the level at the tip of the probe increases as well.
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Hi Sarasir,
Thanks for performing this test and posting the results!
I have to admit that the result of the shielded test was not quite as I imagined, I thought there would be a more significant decrease in noise than what it actually turned out to be. The slight increase in noise with the screwdriver test however is about what I expected.
Again, thanks for the very interesting series of tests!
PS: Thanks for mentioning the aluminum flux, quite a few times I've wanted to solder aluminum but didn't know there was a product designed for this.
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Hi TomC,
Yes, of course your welcome and once more to say, there is always someting new I learn from your ideas...
Sorry for not responding for long time but I was very busy with other projects and just today read your last post.
(I also just forgot to go to the next page and also asked myself what might have happend to you guys...)
As to the flux: clean the aluminum with a glass brush/eraser before applying the flux. This removes the strong oxide and the flux then removes the immediately generated new one but still much thinner surface oxide. Aluminum then can be soldered like chopper or tin sheet. There where various offers on the web and I decided for the simple flux only. Other methods try to sell you more things but with the glass brush or a fine sand paper it's just perfect.
And to the Owon, I redisigned the 5.6V converter, crashed the chip because of a layout fault (even on the tiniest layout sometimes I arrive to oversee something important) and had to order me new controller chips (Digi-Key of Minnesota is really perfectly fast). Also started with the -7.4 converter as I think it should also go into the common little converter tin box as I can see no reson for it to stay on the main PSU board.
Will post the result as soon as possible.
Till then keep up the good spirit...
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Sounds good! :-+
Looking forward to the test results!
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Hi TomC,
finally another step! Should anybody still checking, here the results of denoising the + 5.5V converter (became quiet her, what happened? I also have lots of other things to do but every third day or so I'm able to spend a few houres continuing the SDS-Free-Of-Noise-Project)
So, a few things to say about this switcher:
It behaves a bit different than the +3.3V (the 5.5 controller is not from Texas Instruments). Killed two chips untill I found out that it is very critical concerning the input. Therefor one 33uF Tantal is placed directly on the chip's input. The reason is that the 15uH torroid I used for the filter out the main switching frequency towards the 8.4V input - don't know if it is actually necessary but want to have the thing as clean as possible - 'softens' or correctly said, increases the supply impedance for the controller too much causing it to work more or less erratic. The TI controller of the +3.3V switcher didn't show any problem with a 15uH coil at it's input but I think I will give it also some more uFs for to be on the sure side,
Another difference between these chips is that the Alpha & Omega chip exhibits much more low frequency noise,
and there where ocasional sharp transients on the output of about +/- up to 2 mV. I'm still not sure but got rid of them after some houres of testing different layouts and also replacing the chip several times.
It's very time consuming to trace things like that down and perhaps another chip might be used eventually but do not think that's really necessary as the +5.5V in turn mostly supplies other converters and regulators - we'll see.
You can see the low F noise on the pics showing the output voltage.
I do not have pics of the performance of the original circuit/PCB layout as my 1st SDS's adapter PCB is depopulated and my 2nd SDS I would have to take the adapter PCB out as otherwise there is also the noise generated by the supplied circuitry and therefor no definite measurement could be made. But as far as I remember the noise of the original is far more - in the 50 to 100mV region if not more.
On the pics you can also see some switching noise remainder on the input but that I'm sure will be gone after the circuit has been shielded entirely. I just did not have the time to do that here especially as I know it's effect quite well from denoising the +3.3V converter.
So, hope somebody will read and that it will not take too long to have the next result ready.
Best wishes
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Hi Sarasir,
Congratulations on your design and layout! :-+
The noise is very low, I would say as good as a linear PS!
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Have you seen Owon mixed signal scopes? Please note that they cannot display digital and analog channels at the same time.
Owon MSO 7102TD Short demonstration. (https://www.youtube.com/watch?v=yVGyDvxX22A#ws)
OWON MSO8202T DSO - Logic Analyzer mode (https://www.youtube.com/watch?v=dsUrLJOYqfM#ws)
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Hi guys,
I just started a new thread on the Owon AG1012F Arbitrary Waveform Generator. I bought one of these AWGs from Saelig during cyberweek on impulse. The price for the AG1012F was $239, which is about the maximum I was willing to spend for my hobby. I didn't really take the time to properly research other AWGs in the same price range, mainly, because I already own an Owon SDS7102 DSO and I wanted the ability of playing back waveforms captured on it on the AWG. Since I didn't have much time before the sale ended and it didn't seem to me that this would be possible without going through major conversion gymnastics if I bought a different make, I went ahead and bought the Owon. Now, for good or for bad, my AWG for the foreseable future is going to be the Owon AG1012F!
I've been playing with my new unit for about a week, and since there is no other EEVblog thread on this unit, I gave it a new thread to document my experiences and give others a chance to contribute or comment.
https://www.eevblog.com/forum/testgear/owon-ag1012f-arbitray-waveform-generator/msg572316/#msg572316 (https://www.eevblog.com/forum/testgear/owon-ag1012f-arbitray-waveform-generator/msg572316/#msg572316)
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The test: It is 46 mV Vpp.
update: Exactly after 21:00 its
12 -14 mV Vpp --- acquire peakdetect
8 mV Vpp ---acquire Average 4
Owon: DS7102V
serieno: SDS71021407522
version: 3.5
Very good results!
I see a new firmware 3.5!
At Owon's site the fw is 3.3 still!
I happily received my new SDS7201V (for 'VGA capable) but I can't find where it displays it's existing firmware: it boots to a useless non-informative 'OWON' screen, then immediately to the scope .. not exactly an 'auspicious' beginning! Tried holding down the top 'start' button during boot .. nothing. Went to owon.com 's site for firmware , entered Ser.No. , which was answered thusly: " You already have the latest firmware" .. pretty UNhelpful!!
There must be a way!
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Hi tkjtkj,
Use the utility function as described on pages 63 - 64 of the manual. The attachments are the images straight from the manual. The firmware version is displayed when you press "ABOUT".
Good luck with your new scope! :-+
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Hi guys,
My OWON HDS2062M died (for the second time) and I don't plan to invest more time and money in it... :-BROKE :palm: I got it for quite some time and it was ok for me, even though it had obvious flows (UI and noise).
It is important for me to have handheld capability, hence I am naturally looking at the SDS7102 with its battery option.
I search this thread, but couldn't find anything specific about this mode: is there anything outstanding (good or bad) when operated from battery ?
Last question: Are there "better" handheld scope alternatives (or scope with battery option), up to 1000/1500EUR ?!
Thanks for this gold-mine thread and overall site ! :clap:
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Hi KTy,
I own an SDS7102, although I don't have a battery option I can give you some general information.
Keep in mind that the SDS7102 is not really a handheld unit, although it's quite compact and light for a 100MHz DSO. The battery option is usually about $50 to $60 extra. When fully charged, it can last up to 4 hours depending on what you are doing with the DSO. Some members have reported a slight increase in noise when using the battery.
Hope that helps!
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It is important for me to have handheld capability, hence I am naturally looking at the SDS7102 with its battery option.
I search this thread, but couldn't find anything specific about this mode: is there anything outstanding (good or bad) when operated from battery ?
Although the SDS7102 can run off of a battery, it is not the same as a true, double-insulated, handheld scope - so you shouldn't do floating measurements with it above about 30V. This is stated in the owners manual, where it says:
"When powered by battery, the product must have ground connection. To avoid electric shock, there must be a ground wire connect between ground and the ground port (on the back of product panel)."
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Ok guys, I hear you.
I really need autonomous capability, I measure stuff in engines environment.
So, going slightly off-topic, is there a proper handheld scope in my budget beside OWON ? (I need to look into those "-N" version if they are any good/better)
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It is important for me to have handheld capability, hence I am naturally looking at the SDS7102 with its battery option.
I search this thread, but couldn't find anything specific about this mode: is there anything outstanding (good or bad) when operated from battery ?
Although the SDS7102 can run off of a battery, it is not the same as a true, double-insulated, handheld scope - so you shouldn't do floating measurements with it above about 30V. This is stated in the owners manual, where it says:
"When powered by battery, the product must have ground connection. To avoid electric shock, there must be a ground wire connect between ground and the ground port (on the back of product panel)."
Yes if we talk about "usual" use in "usual" environment.
But, it also depends...
It can of course use for floating mesurements with high voltages if we also follow tight rules for this work.
But, it is professionals work who also fully understand what he is doing and can himself design and do what he is doing and following all working safety rules. No one without enough experience, knowledge and education (and in some cases also certificate for it) must not do it or even try. I know it exatly, I have been there previously and not only once. In my profession history I have been in industry where we really need do work in case where process can not allways shut off and we need do lot of work in running live systems. many times we repair and made changes just in fly without shut of machines. It is very fun to keep small 300kW motor running and change its main contactors and all works so that there was electric on and system running. There really need know what to do or... you breath in copper vapor and die if not die with electric shock or burn due to arc. Also many times there need do some measurements in 5kV power system. With normal tools but with very extremely deep care you self stay floating and well isolated. Yes I also know what read in deep inspection when one work friend die, due to just one small mistake.
DO NOT high voltage (or high current with low voltages) floating measuremeents if you really do not know. You need know, and not only believe you know, before these kind of works. I do not worry your life but I worry your mother, faather, sister, couple, childrens and insurance company.
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Thanks for your feedback.
One thing I should have mentioned is that the "engine" I am referring to are "petrol engines" ^-^
I measure small signals up to 500V, AC.
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Thanks for your feedback.
One thing I should have mentioned is that the "engine" I am referring to are "petrol engines" ^-^
I measure small signals up to 500V, AC.
Have you looked at the Siglent SHS series?
1000 series have isolated inputs and CAT II 1000V rating.
http://www.siglent.com/ENs/pd.aspx?tid=2&T=1 (http://www.siglent.com/ENs/pd.aspx?tid=2&T=1)
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Thanks for your feedback.
One thing I should have mentioned is that the "engine" I am referring to are "petrol engines" ^-^
I measure small signals up to 500V, AC.
You might want to read through this recent thread on handheld scopes (https://www.eevblog.com/forum/testgear/hand-held-scope-opinions-again-please/) - a lot of good information in it from users of various models.
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Thanks for your feedback.
One thing I should have mentioned is that the "engine" I am referring to are "petrol engines" ^-^
I measure small signals up to 500V, AC.
Have you looked at the Siglent SHS series?
1000 series have isolated inputs and CAT II 1000V rating.
http://www.siglent.com/ENs/pd.aspx?tid=2&T=1 (http://www.siglent.com/ENs/pd.aspx?tid=2&T=1)
Thanks, I will check.
I tried a Hantek DSO8060 and had to returned it due to the unreasonable noise level (200mV or so... :wtf:).
Can anyone compare a SDS7102 with a HDS3102M-N in terms of accuracy/noise level ?
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Thanks for your feedback.
One thing I should have mentioned is that the "engine" I am referring to are "petrol engines" ^-^
I measure small signals up to 500V, AC.
Have you looked at the Siglent SHS series?
1000 series have isolated inputs and CAT II 1000V rating.
http://www.siglent.com/ENs/pd.aspx?tid=2&T=1 (http://www.siglent.com/ENs/pd.aspx?tid=2&T=1)
Thanks, I will check.
I tried a Hantek DSO8060 and had to returned it due to the unreasonable noise level (200mV or so... :wtf:).
Can anyone compare a SDS7102 with a HDS3102M-N in terms of accuracy/noise level ?
PM me or post for any checks/tests you'd like me to do with my SHS810.
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Thanks for your feedback.
One thing I should have mentioned is that the "engine" I am referring to are "petrol engines" ^-^
I measure small signals up to 500V, AC.
You need know what you are doing and all safety things for protecct yourself. Human safety is number one!
But then also 500VAc from 0 cross to peak is +710V or -710V
You need look oscilloscope input specifications for maximum level but of course also probe specifications!
No way with 1x/10x probe. (first there come V limit but also if accidentally you turn probe for 1x then good bye to scope input. Broken, permamnently. And in worst case more - it may leak (short circuit) to scope ground.
Minimum is that you buy good trusted HV probe what also have safety classified for HV use. After then you need also know how to work safe. I suspect this some amount because you need ask. (sorry this suspect but I have seen so much in tens of years what all can happend. I have also loosed some my work friend in electric accident in industry (and he was educated and experienced professional)
Do not even try with these probes what come with oscillosscope. They are for low voltage use. Small signals, if you mean small current signals but these high voltages. It do not need much of current to kill people. And kill oscilloscope input do not need even this current what may kill people.
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Hi everybody!!! I´ve been reading your posts regarding OWON SDS series DSO´s and I´m quite surprised by the very few complaints about display colors.
I´ve just purchased an SDS7102V DSO and so far I´m very satisfied with its performance; however, one of the first things I wanted to change was display colors, and it was frustrating to find out that OWON´s designers don´t offer users the freedom to customize display colors... - not even a choice of "skins".
I find the red trace ugly and with poor contrast + CH1 data is displayed in red characters on a black background which are almost unreadable. (I might be a little red-color-blind :P)
I believe RED should be used only for warnings when something goes really wrong.
I´m not an experienced programmer, but there is no doubt that display colors won´t affect the instrument´s performance and changing them should be very easy. Most probably CH1´s color could be changed by simply changing the value of a two-byte integer in a single line of code.
Has anybody examined OWON´s fw? ... - I believe "tinhead" has made huge advances.
I am not interested in hacking any other features, I only want to get a clear view of the waveform´s shape and data.
After all, THAT is the very purpose DSO´s are built for.
Any help will be greatly appreciated.
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I find the red trace ugly and with poor contrast + CH1 data is displayed in red characters on a black background which are almost unreadable. (I might be a little red-color-blind :P)
I've lost a fair amount of my eyesight to glaucoma so I sympathize with you, but you must be color blind to some degree because I find the contrast and readability of the scope to be fine. I would love to be able to change the colors though as I find the red/yellow combination to be less than optimal, or to put a finer point on it, not to be my first choice in colors.
Someone mentioned the colors from the Chinese flag played a role in the selection...
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Someone mentioned the colors from the Chinese flag played a role in the selection...
It was my joke.... but who knows...chhinese like red and yellow.
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I find the contrast and readability of the scope to be fine.
Dear cncjerry: Thank you for your sympathy! :o
This is an unretouched picture I just picked from an earlier post on this thread (at 90% of its original size):
I can see the yellow waveform very clearly and the red one only as a faint thin line. It is VERY sharp indeed (unlike the yellow one) but i´m afraid I might miss some tiny details that would be very obvious if the trace was a little brighter.
I can also read ALL the data displayed on screen but I have to make a little extra effort to read the red characters on black background.
This has led me to use CH2 as "main" and turn CH1 on only when I use both channels. hehehe! :'(
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Do you have persistence turned on? I keep it turned on the lowest setting which is one second. My display doesn't look as finely detailed as yours and I don't know if that is good or bad.
I love the scope and don't regret the purchase one bit even in light of some of the newer Rigol models released since.
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One other note: I went back and displayed the same signal on both channels and I noticed the trace as well as the text in yellow seems to be more anti-aliased. So the yellow text presents as more fuzzy if you follow me.
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I like the scope very much and I don´t regret having bought it. I think it´s a fine piece of equipment and its builders certainly deserve to be very proud of what they have accomplished.
If I only could change CH1´s color I would totally fall in love with it. :)
I usually keep persistence OFF and BTW, the picture is not of my scope but just a random picture I picked from earlier posts to illustrate my point.
I agree with you that the yellow seems a little fuzzy and probably that´s why yellow characters are easier to read.
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IMHO this is due to the fact that yellow is produced by a combination of red and green pixels while red consists of red pixels only.
This makes the red trace extremely sharp and the yellow trace a little "fuzzy".
On the other hand, when it comes to displaying characters, yellow is less prone to contain "blind spots" and characters appear more "rounded" while red characters are likely to have rugged edges, as if there were missing pieces, and this makes them a little harder to read.
Exactly the opposite happens with black characters on red background as you can see in the same picture (The "1" inside a red circle) and compare it to red characters on black background.
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Someone mentioned the colors from the Chinese flag played a role in the selection...
It was my joke.... but who knows...chinese like red and yellow.
.... and yet they don´t use those colors in the splash screen at boot-up. :-//
Dear Mr. rf-loop:
I have been reading this thread for the last few days (I´m not done yet) and:
1. I want to congratulate You for your deep insight and extremely valuable contributions to this thread.
2. Since You are a senior member of this forum, I wonder if You can contact "tinhead" and ask him to give us a hand. I believe he is the most qualified expert on OWON´s firmware.
Yours faithfully, (Ystävällisin terveisin,)
Vytautas Gabriunas
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Someone mentioned the colors from the Chinese flag played a role in the selection...
It was my joke.... but who knows...chinese like red and yellow.
.... and yet they don´t use those colors in the splash screen at boot-up. :-//
Dear Mr. rf-loop:
I have been reading this thread for the last few days (I´m not done yet) and:
1. I want to congratulate You for your deep insight and extremely valuable contributions to this thread.
2. Since You are a senior member of this forum, I wonder if You can contact "tinhead" and ask him to give us a hand. I believe he is the most qualified expert on OWON´s firmware.
Yours faithfully, (Ystävällisin terveisin,)
Vytautas Gabriunas
You can do that yourself with a PM.
Point him to a post with full details of your problem and be patient for his reply.
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You can do that yourself with a PM.
Point him to a post with full details of your problem and be patient for his reply.
Who said that?
I´ve already sent him a PM last week but haven´t got any response. I guess he deleted it unread.
I was just hoping that some old members might know each other :P
HOW can I "point him to a post" Forgive me please.... - never been in a forum before :P
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HOW can I "point him to a post" Forgive me please.... - never been in a forum before :P
"Link" may have been a better word.
Right click post title and "copy address"
Paste in message.
For you replies to posts, use Quote post and then add your message after the "[/quote]"
Or use the "insert quote" below font size box.
There are many features to use and it takes a while to learn them, use the "quote" and you will see how others have built their post.
"Preview" is useful too, to check your post is in the format you want.
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Oh! :-DD Thanks tautech !!! I thought it was a moderator´s message that appeared below my post. DUH!
Thank you again!
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A couple of quick notes on the SDS7102(V) and current software/firmware for it.
For the software, I went to the PC Software tab on the OWON update site (http://www.owon.com.hk/service_s.asp (http://www.owon.com.hk/service_s.asp)) and as of this writing it says that 2.0.8.24 is the latest PC software release... but the link to that software is dead! Thinking maybe the uploads were more up-to-date than the text of the page I tried a few other iterations, and found that there *is* a OWON_Oscilloscope_2.0.8.26_Setup.rar there. I downloaded it, ran it through a few AV scanners to be extra cautious, and installed it. It seems to work and the "About" box says it's "Version 2.0.8.26 (build 20141228)". YMMV of course.
For the firmware, I went to the Firmware tab, entered my serial (be sure to omit the last three digits or you'll be told incorrectly that "The firmware onto your OWON device is in latest version, no need to upgrade, thanks") and downloaded "sds_upgrade_3.2_3.3_3.4.rar". I installed it and now I'm up to version 3.8 on the scope. As usual it started with Chinese menus so I did the "Utility -> H2 -> English" maneuver to change it to English, and that worked fine... until I rebooted the scope and saw that it was right back to Chinese! Tried changing it again, power cycled and back to Chinese! Hmm.
For grins I power cycled, changed the language to English and then set the clock to something other than the default. *That* apparently helped make the setting stick, and it's been on English ever since.
tl;dr - After updating to this firmware, update the language *and* set the clock... it doesn't seem to stick otherwise.
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A couple of quick notes on the SDS7102(V) and current software/firmware for it.
For the software, I went to the PC Software tab on the OWON update site (http://www.owon.com.hk/service_s.asp (http://www.owon.com.hk/service_s.asp)) and as of this writing it says that 2.0.8.24 is the latest PC software release... but the link to that software is dead! Thinking maybe the uploads were more up-to-date than the text of the page I tried a few other iterations, and found that there *is* a OWON_Oscilloscope_2.0.8.26_Setup.rar there. I downloaded it, ran it through a few AV scanners to be extra cautious, and installed it. It seems to work and the "About" box says it's "Version 2.0.8.26 (build 20141228)". YMMV of course.
For the firmware, I went to the Firmware tab, entered my serial (be sure to omit the last three digits or you'll be told incorrectly that "The firmware onto your OWON device is in latest version, no need to upgrade, thanks") and downloaded "sds_upgrade_3.2_3.3_3.4.rar". I installed it and now I'm up to version 3.8 on the scope. As usual it started with Chinese menus so I did the "Utility -> H2 -> English" maneuver to change it to English, and that worked fine... until I rebooted the scope and saw that it was right back to Chinese! Tried changing it again, power cycled and back to Chinese! Hmm.
For grins I power cycled, changed the language to English and then set the clock to something other than the default. *That* apparently helped make the setting stick, and it's been on English ever since.
tl;dr - After updating to this firmware, update the language *and* set the clock... it doesn't seem to stick otherwise.
Thanks for the info! :-+
I just downloaded OWON_Oscilloscope_2.0.8.26_Setup.rar using your tip! As you implied, all I had to do is change the 24 to 26 on the address bar of the screen with the Oops! message.
A couple days ago I also downloaded the firmware because it had a later date than my current version, but after installing it I still had version 3.8 on my scope. However, I didn't run into the problem of it reverting back to Chinese.
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Thanks for the info! :-+
I just downloaded OWON_Oscilloscope_2.0.8.26_Setup.rar using your tip! As you implied, all I had to do is change the 24 to 26 on the address bar of the screen with the Oops! message.
A couple days ago I also downloaded the firmware because it had a later date than my current version, but after installing it I still had version 3.8 on my scope. However, I didn't run into the problem of it reverting back to Chinese.
Glad it was useful! You probably didn't run into the Chinese default problem because it didn't actually change your firmware (I'm guessing there's a checksum that if changed (e.g., after the firmware changes) leads to it setting the NVRAM to default across the board - what was weird was that changing the language wouldn't "stick" until I also set the clock).
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Has anyone come across this fault.
The oscilloscope powers with up green light and fan runs but no display.
I checked the voltages at the pins there are voltages at the J3 connector pin (5 and 6) 8.4V pin 4 seems slightly high 7.84V instead of 7.6V A.C trigger 1.435V. GLED 11.75V RLED 0.5mV. There is a bulging capacitor on the board C4 not sure how much difference or how this will effect the board it has 8.4V across it. But is showing some ripple.
is anyone able to compare the voltages or help with this.
Thanks
R_G_B
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Has anyone come across this fault.
The oscilloscope powers with up green light and fan runs but no display.
I checked the voltages at the pins there are voltages at the J3 connector pin (5 and 6) 8.4V pin 4 seems slightly high 7.84V instead of 7.6V A.C trigger 1.435V. GLED 11.75V RLED 0.5mV. There is a bulging capacitor on the board C4 not sure how much difference or how this will effect the board it has 8.4V across it. But is showing some ripple.
is anyone able to compare the voltages or help with this.
Thanks
R_G_B
Hi R_G_B_,
Sorry you are having trouble with your scope. Some time ago, many posts on this thread, I did some work on the main PSU and reverse engineered the attached schematic. In my opinion you should replace the bulging capacitor, there should be almost no ripple on the 8.4V. This voltage is used by several other DC/DC converters on the adapter board, and ripple can cause problems, possibly what you are seeing.
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has this been a common problem with this oscilloscope?
What else should I watch out for?
Thanks TomC
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Fixed I replaced the capacitor 1000uf 16V on the power supply board for a 15V 1000uf i salvaged from an old free view set top switch mode power supply board. The oscilloscope switches on. Thanks again TomC.
R_G_B_
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Fixed I replaced the capacitor 1000uf 16V on the power supply board for a 15V 1000uf i salvaged from an old free view set top switch mode power supply board. The oscilloscope switches on. Thanks again TomC.
R_G_B_
Glad to hear that! :-+
Most of the problems I had were self inflicted while experimenting trying to alleviate the noise issue. But I guess some of these scopes are reaching the age where capacitors, etc., start to fail. Anyway, that's great news that you got it back working!
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Having read the reviews of this oscilloscope I have many questions.
Seems to be problem with noise. I have had to use ferrite beads on the internal cables and probes. I manged to get the noise down to around 20mv but this is still bad compared to my old TDS1002 I its around 3mv and this is a very old scope. I had seen Daves review of the 300MHz version of this scope it did not go down to well. Have the software issues been sorted?
the version of software I have is version 2.7. The V version of the scope. Any help appreciated.
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I don't have a noise problem in mine for a scope in that price range. Was your's an early model?
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On the main board it says 2012 SDS71021234.
Tektronix were way ahead of the game back in their day.
The TDS1002 seems very slow but solid in terms of functionality does what it suppose to do for its time and its still going after all this time.
R_G_B_
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just updated the firmware to 3.3 and the screen has gone corrupt? can anyone help?
thanks
R_G_B_
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My verdict Unfinished product ....terrible software. I'm keeping the tds1002. And Getting rid of this piece of junk. I'm sure people will hate me for saying this. But I just updated the scope firmware and it corrupted the text on the display and now I can not know what's happening as I can not read the display.
R_G_B
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Maybe you have it in Chinese language? Ha!
I have a tek 3054b, TDS794C, and a couple others. I pull the Owon SDS7102V out all the time because it has a large screen, is light, and I can see everything on that scope that I can see on the others if I set persistence correctly. Yes, the triggering and some of the other features on the better scopes make it look like a toy, but still, for everyday use I love mine.
I would reflash the firmware back. There are two versions of that scope, I believe, and two sets of firmware.
Jerry
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The only thing I've noticed after updating firmware is that the language defaults to Chinese. If that's the case press Utility, H2, and select the language with the knob.
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My scope has the serial number SDS71021234 I updated it to firmware 3.8.
Its corrupted the text on the display its not chineese text its a scrambled looking graphic instead of letters and numbers. It was on firmware 2.7.1 before I up dated the firmware how do I get it back to this firmware its not on owon website?
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R_G_B,
If it was me I would download the firmware again and try to do the update a second time. Based on your serial it seems that you should download the upgrade illustrated on the attachment. As far as other versions of the firmware, I've never tried to go back to an earlier version, so I'm not sure if that would help. I do have some earlier files in my PC as I'm a bit of a hoarder, but not 2.7.1. The earliest I've got is 3.1, if nothing else works and you want to take a chance I could upload it to onedrive.
PS. By the way, Chinese will look like graphics, not letters and numbers.
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Thanks TomC I sorted it.
Its the firmware not displaying the chinese text properly it was corrupted. Anyway I did the utility H5 as you described changed to English.
The Volts/Div goes down to just 20mV I take it this is because of the noise issues?
Thanks
R_G_B
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Thanks TomC I sorted it.
Its the firmware not displaying the chinese text properly it was corrupted. Anyway I did the utility H5 as you described changed to English.
The Volts/Div goes down to just 20mV I take it this is because of the noise issues?
Thanks
R_G_B
With the probe setting in the Ch1 or Ch2 menu set to x10 you can only go down to 20mV/div. If you change the setting to x1 then you can go down to 2mV/Div. This scope doesn't sense the setting of the probe switch automatically.
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Yes I was to focused on problems with this and had forgot that I had set the scope probe to x10.
Thanks TOMC.
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Have anybody checked that the waveform update rate problem has solved or not? I think it was maximum 35 per second.
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I recently posted an experiment where I explore the possibility of using the SynthUSBII Signal generator and the CPDETLS-4000 power detector to get a better idea of the frequency response of a DSO beyond the manufacturer's specified bandwidth. Hopefully, this knowledge can help the user determine the amplitude of signals that exceed the DSO's specified bandwidth and thus extend the usefulness of inexpensive lower bandwidth DSOs.
The example DSO I used for this experiment is my Owon SDS7102 DSO, so this information may be useful for other SDS7102 owners. If you are interested click on the following link:
https://www.eevblog.com/forum/testgear/synthusbii-usb-rf-signal-generator-cpdetls-4000-rf-power-detector/msg870496/#msg870496 (https://www.eevblog.com/forum/testgear/synthusbii-usb-rf-signal-generator-cpdetls-4000-rf-power-detector/msg870496/#msg870496)
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Have anybody checked that the waveform update rate problem has solved or not? I think it was maximum 35 per second.
That was a specification, not a problem. This scope was introduced in 2010, I think.
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I recently posted an experiment where I explore the possibility of using the SynthUSBII Signal generator and the CPDETLS-4000 power detector to get a better idea of the frequency response of a DSO beyond the manufacturer's specified bandwidth. Hopefully, this knowledge can help the user determine the amplitude of signals that exceed the DSO's specified bandwidth and thus extend the usefulness of inexpensive lower bandwidth DSOs.
The example DSO I used for this experiment is my Owon SDS7102 DSO, so this information may be useful for other SDS7102 owners. If you are interested click on the following link:
https://www.eevblog.com/forum/testgear/synthusbii-usb-rf-signal-generator-cpdetls-4000-rf-power-detector/msg870496/#msg870496 (https://www.eevblog.com/forum/testgear/synthusbii-usb-rf-signal-generator-cpdetls-4000-rf-power-detector/msg870496/#msg870496)
I recently updated the Graphs and Spreadsheets associated to this post. If you are interested click on the following link:
https://www.eevblog.com/forum/testgear/synthusbii-usb-rf-signal-generator-cpdetls-4000-rf-power-detector/msg875416/#msg875416 (https://www.eevblog.com/forum/testgear/synthusbii-usb-rf-signal-generator-cpdetls-4000-rf-power-detector/msg875416/#msg875416)
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Guys, any idea on the encryption for the files that come in the firmware archive?
I am trying to decrypt them but have no clue on the algorithm used. The keys are in the txt file.
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Nevermind, I read some more and I understood that there's a tool in the firmware update package.
The problem is that I'd like to experiment a bit with calibrating the scope (sds6062). It's a bit out and seems like fun.
I managed to start the encryption/decryption tool but it's a mess.
For source I can only select a folder, and for destination only a file. And the decrypt button doesn't do anything actually.
Any pointers from someone who did this?
I only need to download the tx.txt file from the scope and adjust some parameters - reupload - repeat.
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Hi!
Please excuse my bad English. This is Google Translate.
I have heard that last oscilloscope models have a passive cooling system. That is not the cooler in them. Do you have someone photograph of a radiator? Which chip closes the radiator? I want to do, and at its SDS8202 passive cooling system.
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Sharing information on its completions SDS8202
1. Tired of cheap fan noise. I had to change. The original 60h60h10mm, 12V, 0.2A, powered by 8.4V. It was fixed at the bottom of the metal radiator. In order to reach and change, I had to disassemble 90% of the oscilloscope including a trail of the film, which is very much did not want to disconnect.
As a replacement was selected http://www.citilink.ru/catalog/computers_and_notebooks/parts/coolers/944770/ (http://www.citilink.ru/catalog/computers_and_notebooks/parts/coolers/944770/)
Which had good reviews on work and noise, but had 60h60h12mm sizes.
Despite the fact that there were doubts whether it will get thicker fan and even on top of the metal-housing land (so that you can replace it without total analysis of the oscilloscope), all successfully. Fans 12mm thickness fit overhead. I had just rewire the power connector from the fan, replacing it with the old one.
However, I think this is still a temporary solution, because I do not see anything too much energy-intensive, that is hitting the fan. Only 2 cases, which suggests to put in place an ordinary radiator fan, although the question remains open of the fastening of a radiator.
I would be very grateful to those who have shown the interior of the oscilloscope with a passive cooling system in the new revisions of the oscilloscope.
2. Current 15mA from the battery in the power supply in the off position, I also did not suit, with the result that I have been able to reduce it to 3mkA using SMD diode Schottky B320B, designed for permanent and 3A to 100A per pulse (which has been removed from the motherboard or graphics card).
It looks like this: (1 photo)
Rosin flux, which the power supply board was just filled, it was necessary to wash long and hard alcohol.
The voltage + VDD to the power supply unit connector terminals 5,6 and plug the battery, of course, it dropped to 8.23V. I began to look divider that controls the setting of + VDD. And here I was waiting for the first TH. The scheme, which I was not consistent with my power supply. (Figure 2)
My power supply is labeled PCB-T115-J Rev6 it lacks the LM393, LM358 is used instead of a quad LM124, a resistor, performing the same function are labeled differently, J2 switch is not paired contacts, but in general a lot of differences. However, I managed to find a resistor that is responsible for voltage control - it was R17, which was parallel to the empty space to install R18. the selection method has been found that setting in the ready-made holes resistor denominated 33kOm, managed to do exactly equal to + VDD 8.4V. (Photo 3 of this resistor location showed a red arrow).
However, the scheme is written that is also required to recalculate R34, R38 (the threshold of extinction of the red LED - charge indicator) for a complete revision. But on its power supply analogues of these resistors I found it was not possible. So the question is: Is someone these dividers on its power supply if they have the same PCB-T115-J Rev6 like me.
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Hi Friend! who can send Nand Dump for owon sds7102 ?
after the firmware my eds102 i have yellow screen
(http://s015.radikal.ru/i330/1604/75/c4aedd20edfb.jpg)
how do I fix it?
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Hi Friend! who can send Nand Dump for owon sds7102 ?
after the firmware my eds102 i have yellow screen
how do I fix it?
Welcome to the forum.
PM member OWON, their details are in this thread:
https://www.eevblog.com/forum/testgear/owon-xds3102a-oscilloscope-unpack-review/ (https://www.eevblog.com/forum/testgear/owon-xds3102a-oscilloscope-unpack-review/)
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PM member OWON, their details are in this thread:
https://www.eevblog.com/forum/testgear/owon-xds3102a-oscilloscope-unpack-review/ (https://www.eevblog.com/forum/testgear/owon-xds3102a-oscilloscope-unpack-review/)
Thanks, but your link for OWON XDS3102A, but i have eds102cv it sds7102 for China
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PM member OWON, their details are in this thread:
https://www.eevblog.com/forum/testgear/owon-xds3102a-oscilloscope-unpack-review/ (https://www.eevblog.com/forum/testgear/owon-xds3102a-oscilloscope-unpack-review/)
Thanks, but your link for OWON XDS3102A, but i have eds102cv it sds7102 for China
OK, you are new to the forum so I'll make it clearer.
Robin from OWON when registering with EEVblog made his contact details available for us all, including you!
You can personal Message him through the forum or use the email link he's provided.
Contact details are in each of our profiles, Robins profile:
https://www.eevblog.com/forum/profile/?u=119064 (https://www.eevblog.com/forum/profile/?u=119064)
Please let us know about the support he offers for your problem.
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Thanks!
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Problem solved, I used to dump on the other oscilloscope, and added in his own settings
(http://s017.radikal.ru/i411/1604/6e/87742a9df07d.jpg)
If you have any questions, please contact me by e-mail: Vasiliy455@yandex.ru
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Just a little teaser... I have this dumb idea of porting Linux to my SDS7102 scope and have managed to get a Linux kernel running on Samsung S3C2416 CPU with a working serial port and frame buffer.
That was the easy part. Adding support for all the other hardware is going to be a bit more tricky. USB and ethernet ought to be fairly easy, they are either standard components inside the CPU or chips with exposed pins. Figuring out how to program the FPGA and how the FPGA is connected to the ADC and the other DDR memory is going to be a lot harder since all those chips are BGA packages and I can't probe the pins.
This thread is really long and I haven't read every post yet and might have missed some so I'm wondering if anyone else has managed to find out interesting things about the hardware. Has anyone done a dissassembly of the firmware and figured out how to program the FPGA or just happens to have access to an XRAY machine and can take a picture of the traces embedded in the PCB and under the BGA packages?
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I'd try and disassemble the original firmware to figure out how to access the acquisition hardware. It won't be easy though but if the hardware is decent others may chime in if you create a wiki-ish website about the project somewhere.
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The stuff in the firmware isn't that much of a problem. I can probably write most of that from scratch, it's mostly a couple of GPIO pins and a few SPI or I2C busses. To program the FPGA they are most probably using slave parallel mode or JTAG and I'll probably have to a bit of disassembly to figure out how that works.
But all the interesting stuff, how the FPGA is connected to the ADC and to the DRAM is hidden in the FPGA bitstream. And I have no idea at all how to disassemble that one.
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Since I don't have a life I've written a few blog posts about reverse engineering the SDS7102 and getting Linux to boot on it:
http://blog.weinigel.se/2016/05/01/sds7102-hacking.html (http://blog.weinigel.se/2016/05/01/sds7102-hacking.html)
http://blog.weinigel.se/2016/05/06/sds7102-hacking-2.html (http://blog.weinigel.se/2016/05/06/sds7102-hacking-2.html)
http://blog.weinigel.se/2016/05/07/linux-on-sds7102.html (http://blog.weinigel.se/2016/05/07/linux-on-sds7102.html)
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Since I don't have a life I've written a few blog posts about reverse engineering the SDS7102 and getting Linux to boot on it:
http://blog.weinigel.se/2016/05/01/sds7102-hacking.html (http://blog.weinigel.se/2016/05/01/sds7102-hacking.html)
http://blog.weinigel.se/2016/05/06/sds7102-hacking-2.html (http://blog.weinigel.se/2016/05/06/sds7102-hacking-2.html)
http://blog.weinigel.se/2016/05/07/linux-on-sds7102.html (http://blog.weinigel.se/2016/05/07/linux-on-sds7102.html)
It is really amazing, nice!
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A lot of more words about the SDS7102 scope :-)
http://blog.weinigel.se/2016/05/14/disassembling-the-sds7102-bootloader.html (http://blog.weinigel.se/2016/05/14/disassembling-the-sds7102-bootloader.html)
http://blog.weinigel.se/2016/05/15/sds7102-file-system.html (http://blog.weinigel.se/2016/05/15/sds7102-file-system.html)
http://blog.weinigel.se/2016/05/16/sds7102-os-disassembly.html (http://blog.weinigel.se/2016/05/16/sds7102-os-disassembly.html)
I'm a bit stuck now though. As far as I can tell they use the Xilinx MIG for talking to the DDR2 memory on bank 3 of the FPGA, but there seems to be no free pin for the RZQ signal which is in direct violation of the Xilinx MIG design rules. But I'm getting ahead of myself. I think I have enough material for another four blog posts or so and will get to that later.
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I've been a bit busy with work but finally found time to write a bit more about the SDS7102.
http://blog.weinigel.se/2016/05/27/another-look-at-sds7102-hardware.html (http://blog.weinigel.se/2016/05/27/another-look-at-sds7102-hardware.html)
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And a bit more.
http://blog.weinigel.se/2016/05/28/sds7102-gio-pins.html (http://blog.weinigel.se/2016/05/28/sds7102-gio-pins.html)
http://blog.weinigel.se/2016/05/29/sds7102-fpga-pins.html (http://blog.weinigel.se/2016/05/29/sds7102-fpga-pins.html)
Just a few more posts and I will have caught up to where I actually am.
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Holly $ht man !! you are really killing it. :-+ :clap:
I do firmware stuff for a living too and I really enjoyed the read. Keep up the good work .. I have one of the scopes and if time (read that 2 kids) lets me I may join in the play
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Hi,
Really nice "work" !! Can't wait for the next episode ;)
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I've been a bit busy with work again, but finally found time to write a bit more about the scope.
http://blog.weinigel.se/2016/06/19/sds7102-more-fpga-pins.html (http://blog.weinigel.se/2016/06/19/sds7102-more-fpga-pins.html)
This is about as good as it gets I think. I've figured out how most of the parts of the scope fit together and unfortunately I'm not sure if I'll ever be able to get the two DDR interfaces to work (one DDR interface to the Soc/CPU where the FPGA emulates a DDR memory, another DDR interface to a DDR memory chip). Without these two parts the scope will never be able to update the screen quickly or store deep traces, but I'm probably still going to try to get the ADC to work and see if I can at least prove that everything works the way I think it does.
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I lied. I had a bit more material left in my notes. Here's a short look at the front panel.
http://blog.weinigel.se/2016/06/21/sds7102-front-panel.html (http://blog.weinigel.se/2016/06/21/sds7102-front-panel.html)
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Hello,
I have an oscilloscope OWON SN: SD71021407245. When I was updating the firmware, there was a problem with the power and now the screen flashes yellow.
Now when I connect the oscilloscope via USB to PC, nothing happens.
How I can fix it? Someone has a complete binary of memory?
Best regards.
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I've managed to capture samples from the ADC:
http://blog.weinigel.se/2016/07/08/sds7102-capture.html (http://blog.weinigel.se/2016/07/08/sds7102-capture.html)
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Just to let you know I read your reports! :-+
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This is way cool!
Sent from my iPad using Tapatalk
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Hello,
I have an oscilloscope OWON SN: SD71021407245. When I was updating the firmware, there was a problem with the power and now the screen flashes yellow.
Now when I connect the oscilloscope via USB to PC, nothing happens.
How I can fix it? Someone has a complete binary of memory?
Best regards.
Read the last few pages of this thread. Pretty sure at least one other person reported having the same issue as well as what they did to fix it.
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Hello,
I have an oscilloscope OWON SN: SD71021407245. When I was updating the firmware, there was a problem with the power and now the screen flashes yellow.
Now when I connect the oscilloscope via USB to PC, nothing happens.
How I can fix it? Someone has a complete binary of memory?
Best regards.
Read the last few pages of this thread. Pretty sure at least one other person reported having the same issue as well as what they did to fix it.
Hi, I've done a dump of another SD7102 and I use that binary to program my oscilloscope.
The result is that the screen is yellow. I have written to vas455 but I have not yet received a reply.
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And a bit more:
http://blog.weinigel.se/2016/07/10/sds7102-soc-bus.html (http://blog.weinigel.se/2016/07/10/sds7102-soc-bus.html)
Next up, controlling the analog frontend and the ADC. I've mostly finished this but haven't written anything about it yet.
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This can be very helpful. A volunteer, to translate?
"tpwire" problem was solved using this info:
http://radiokot.ru/forum/viewtopic.php?p=2807326&sid=1f74f269e41f1a86c91f95d3faa7881e#p2807326 (http://radiokot.ru/forum/viewtopic.php?p=2807326&sid=1f74f269e41f1a86c91f95d3faa7881e#p2807326)
@ wingel (Christer)
What you're doing is amazing, thanks for sharing. :-+
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Really nice project that you are doing there!
I actually consider to buy this scope, just to follow your project and play along at home :) It makes learning FPGA stuff just more cool!
After your project is finished, you should consider publishing a book, with all the findings, and you could sell it together with the scope in an educational bundle package =)
I've managed to capture samples from the ADC:
http://blog.weinigel.se/2016/07/08/sds7102-capture.html (http://blog.weinigel.se/2016/07/08/sds7102-capture.html)
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One final post. Or not. Anyway, with this I have basically documented how everything in the scope fits together.
http://blog.weinigel.se/2016/07/15/sds7102-afe.html (http://blog.weinigel.se/2016/07/15/sds7102-afe.html)
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In case I would buy this scope, to follow your project and play along at home, would it be possible for me, to open up the scope just once, mount the JTAG cable and other debugging cables into the scope, and after close it again?
This would keep my bench tidy, while at the same time I would have full access to the scope, to control and monitor it from the JTAG interface and the other debugging cables.
Owon SDS7102-D: D for debugging option =)
Maybe a small batch of these scopes can be produced, for an FPGA and DSP class room :)
Another option that I can see: Use everything from the scope, including the analog front-end, the controls and knobs, the display, the power supply, but bypass the main processor and insert a Xilinx Zynq-7000 instead. This could in fact be the Zybo board from Digilent. Would it be easy to redirect the output of the analog front-end? Or would it be possible to tri-state the main FPGA and take over control through a Xilinx Zynq-7000? Would there be space inside to add an extra Zybo board without replacing an existing board?
Using this modification, you could retro-fit the Owon scope and convert it into a powerful scope with super powers that beats the GW-Instek GDS-2000E :)
Owon SDS7102-Z: Z for Zynq-7000 option =)
Also here, maybe a small batch of these scopes can be produced, for an FPGA and DSP class room :)
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If you aren't bored with me yet.
I've put the source code for my Linux port and FPGA image on github.
http://blog.weinigel.se/2016/07/16/sds7102-source.html (http://blog.weinigel.se/2016/07/16/sds7102-source.html)
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In case I would buy this scope, to follow your project and play along at home, would it be possible for me, to open up the scope just once, mount the JTAG cable and other debugging cables into the scope, and after close it again?
Yes, this is how my scope looked for the first few weeks, three wires for the 3.3V serial port (GND, Tx, RX) and a handful more of wires for JTAG (GND, VREF, TMS, TCK, TDI, TDO, RST). I had to remove a bit of plastic to be able to bring the JTAG cables out of the unit.
(http://blog.weinigel.se/images/2016-05-06-sds7102-hacking-2/debug-connectors.jpg)
Actually the boot loader protocol in the scope doesn't seem to be that complex so it should be possible to load Linux into flash on the scope using just a USB cable. But that would be a one way street, it would overwrite the original OWON firmware in flash with no way of making a backup and I don't know if it's possible to restore the original firmware after doing that.
Another option that I can see: Use everything from the scope, including the analog front-end, the controls and knobs, the display, the power supply, but bypass the main processor and insert a Xilinx Zynq-7000 instead. This could in fact be the Zybo board from Digilent. Would it be easy to redirect the output of the analog front-end? Or would it be possible to tri-state the main FPGA and take over control through a Xilinx Zynq-7000? Would there be space inside to add an extra Zybo board without replacing an existing board?
I guess it would be doable in theory, the FPGA ought to three-state all pins if it's not configured, so it should be possible to solder wires onto the SPI busses and chip selects and ADC wires. In practice, no, the signal integrity of the ADC signals would be awful. And there isn't space in there for an extra PCB anyway.
What would be doable would be to create a new main PCB with a Zynq, ADC, analog fronten and all the connectors on it and just reuse the front panel and LCD board. But that would cost a lot and probably not be worth the time and money. It would be a fun project though.
Actually my dream 1Gsps/100MHz scope would be something like that. I like the form factor of the OWON scope, I like the screen and the physical layout, I like having a built in battery. But it would be very nice with a Xilinx Zync or Altera Atlas with a lot more CPU power. a couple of hundred megabytes of sampling memory and gigabit ethernet.
Anybody up for a kickstarter? :-)
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I already suggested this in my separate thread about DSO manufacturers using the Xilinx Zynq-7000 series.
See my separate thread about this: Retrofit kit and open source bench oscilloscope
https://www.eevblog.com/forum/testgear/other-dso-manufacturers-besides-gw-instek-that-use-xilinx-zynq-7000-series/msg983966/#msg983966 (https://www.eevblog.com/forum/testgear/other-dso-manufacturers-besides-gw-instek-that-use-xilinx-zynq-7000-series/msg983966/#msg983966)
You can compare it with some of the mountain bikes from the German company Bulls back in the days.
For 1000 EUR, you could get a mountain bike fully spec:ed with Deore XT parts, both in the front and the back. Some people just bought the mountain bike for parts. They would discard or sell the frame, and mount the parts on a new frame. This was much cheaper than buying the Deore XT parts yourself, even if you paid for a frame that you are not using, because Bulls had such a high turnover, they could buy these Deore XT parts in big quantities. Today, you can still buy such a mountain bike from Bulls with Deore XT parts at a similar price. But now people don't discard the frame anymore, because now the frame is premium as well :)
In the case of the oscilloscope, we would actually do the other way around. We only keep the build mechanics, the plastics, and the overall physical design. Chinese oscilloscope manufacturers, are extremely good at the build mechanics, the molding of the plastics, and the overall physical design. There is no way, to beat that as a small player. But on the electronics side however, it would be very feasible to spin your own PCB board, that adds super powers to your existing bench oscilloscope! :)
It would definitely be a nice Kickstarter project!
Where are you based in Sweden? I used to live in Linköping.
We could call the Kickstarter project as follows:
"The Scandinavian Retrofit Kit for a bench oscilloscope: Add Zynq-7000 super powers to your existing bench oscilloscope!" =)
But what base model should we select for the bench oscilloscope upgrade? We could go for a Rigol DS1054Z, as those are out there in the most quantities! Or do you suggest another base model?
BTW: One of my former colleagues works at a company in Linköping that is specialized in ADC technology.
One of the projects he worked on, was the design of a PCB board, for an entry level LeCroy oscilloscope,
that used the ADC technology from his company. Maybe we could use their technology for the PCB board :)
I can check with my former colleague, if he would be interested in helping out for, or being part of, such a Kickstarter project.
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Forget about connecting an ADC to a different board. The signals carry such high frequencies that it will not work over any kind of wiring. Besides that connecting the wires will be a nightmare as well. IMHO the best thing to do is create an entirely new board (analog frontend + digital parts) which fits in an existing scope case OR buy an existing scope which already has the hardware you like and reverse engineer that so it can run your own firmware. In that respect reverse engineering the Owon is a bit of a waste of time because creating a scope with decent performance in a reasonable timeframe will be very hard (if it is possible due to limited FPGA, bandwidth and processing resources).
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The SDS7102 (or rather one of the cheaper models) would be a fairly nice scope for such a retrofit in that case since it is modular, you'd be able to keep the front panel and LCD boards and only have to replace the main PCB. The Rigol 1054Z seems to be one big PCB so you'd have to replace everything.
I live in Stockholm, used to study in Linköping . Google my name, there's only one Weinigel in the whole of Sweden. :-)
I might know your colleague too, there were a couple of guys from Admittansen that did rather groundbreaking work on time multiplexing/interleaving of ADCs in Linköping.
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It seems that input attenuator of my scope went out of calibration.
An input attenuator in SDS7102 has 3 ranges: 1:1 (active when V/div is 100 mV/div or less), 10:1 (200 mV/div - 1 V/div), and 100:1 (2 V/div or above). Range is selected by relays, so when you change V/div you can hear if the range is changed.
Divider compensation is adjusted by C9 at 10:1 and by C10 at 100:1. - C9 and C10 would not cause such a sharp overshoot, so probably they are correctly adjusted.
On da_1.png the same signal is measured on 100 mV/div (1:1) and on 200 mV/div (10:1). You can see that at 1:1 (100 mV/div) square wave is really square, so the amplifier works correctly, but at 10:1 (200 mV/div) the attenuator is overcompensated. Switching between 10:1 and 100:1 shows that at 100:1 compensation is even worse comparing to 10:1.
The same problem is on both channels.
Has anybody a similar problem?
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What if we keep the existing PCB board, and use the existing FPGA as a gateway towards the new PCB board? This way we would not affect the original ADC circuitry, while at the same time still have access to it!
Forget about connecting an ADC to a different board. The signals carry such high frequencies that it will not work over any kind of wiring. Besides that connecting the wires will be a nightmare as well. IMHO the best thing to do is create an entirely new board (analog frontend + digital parts) which fits in an existing scope case OR buy an existing scope which already has the hardware you like and reverse engineer that so it can run your own firmware. In that respect reverse engineering the Owon is a bit of a waste of time because creating a scope with decent performance in a reasonable timeframe will be very hard (if it is possible due to limited FPGA, bandwidth and processing resources).
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What if we keep the existing PCB board, and use the existing FPGA as a gateway towards the new PCB board? This way we would not affect the original ADC circuitry, while at the same time still have access to it!
Then you'd have to go through the existing SoC. You might as well just talk to the scope over ethernet and you won't have fast access to the data in the FPGA. I think you either make do with what the existing hardware can do or you have to bulid a new main PCB.
I'm planning for the first, see what I can do with the existing hardware. If that works out fine and I somehow get a lot of money it would be fun to try to replace the main board, but I don't think that'll happen.
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I agree that the first step is to use the existing hardware, and see how far you can get with that approach.
Keep us posted about the progress of your project! :)
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By the way. I'm quite convinced that I saw a open source scope project where they used a FPGA and had a fairly nice looking plastic housing for it. I think it was a german project and I think they had some major issues with it. But I can't find that project any more. Do any of you remember it?
And since I basically know how everything about how the scope fits together now I need to start writing some software for it. Is there any open source software out there that I can reuse? Should I just use fbdev for the graphics? SDL, X, Wayland? GTK, QT? Any existing controls that can be reused? Or any existing verilog/VHDL code I can look at?
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There used to be a scope on the market from a German firm which went belly up. I think they released the firmware but it was such a huge mess people started from scratch. But as I already wrote: when it comes to oscilloscope firmware you probably end up writing at least 3 versions from scratch before you understand the difficulties OR you have to start with a very detailed plan. A good starting point is to assume each trace consists of sample & timestamp pairs which then need to be plotted onto a screen from time X to time Y.
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Welec 2000A, that's the German scope. I just needed something to jog my memory. I was wondering if there was any source code for that scope that could be useful.
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Yes, the Welec Wittig scope! My memory was rusty as well. It seems they are still working on it (much to my own surprise!) because the last commit on the project was 6 days ago:
https://sourceforge.net/projects/welecw2000a/
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Never heard about Welec or Wittig before. Must have missed that part!
But then again, at that time, I did not have much focus on test and measurement equipment.
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It would be interesting to see how easy/difficult it is to port the opensource Welec firmware to the Owon scope.
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Or maybe it is better to start from scratch, and use High-Level Synthesis and an "All-in-C" based design.
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It's too warm to sleep here in Stockholm so here's another blog post:
http://blog.weinigel.se/2016/07/25/sds7102-fast-buses.html (http://blog.weinigel.se/2016/07/25/sds7102-fast-buses.html)
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Yes, the Welec Wittig scope! My memory was rusty as well. It seems they are still working on it (much to my own surprise!) because the last commit on the project was 6 days ago:
https://sourceforge.net/projects/welecw2000a/ (https://sourceforge.net/projects/welecw2000a/)
Already known: https://www.eevblog.com/forum/testgear/welec-w2000a-another-weird-oscilloscope/msg361147/#msg361147 (https://www.eevblog.com/forum/testgear/welec-w2000a-another-weird-oscilloscope/msg361147/#msg361147)
Welec was probably shit.
This happened in 2007 when Rigol and Siglent were quite unknown in Europe.
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Little update on my 7102, that has always suffered of heavy backgroud noise (as much that i've had 200mvpp noise with the 20mv/div setting on 10x). Simply washing deeply the boards (first water+soap, then some degreasers, at the end demineralized water and isopropyl alchool) have solved all my problems, now almost no backgroud noise. Had also to remove the shield aroud the analog section for ash deeply under it.
A little thing to notice is that the ground of the "compensating output" have some nasty noise but don't bother me as not affect the measurements...
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Little update on my 7102, that has always suffered of heavy backgroud noise (as much that i've had 200mvpp noise with the 20mv/div setting on 10x). Simply washing deeply the boards (first water+soap, then some degreasers, at the end demineralized water and isopropyl alchool) have solved all my problems, now almost no backgroud noise. Had also to remove the shield aroud the analog section for ash deeply under it.
A little thing to notice is that the ground of the "compensating output" have some nasty noise but don't bother me as not affect the measurements...
Interesting. I've also noticed some ashy residues on the main PCB in my scope too. I didn't think that would affect the measurements though. But now when you mention it, if that ash is conductive it could carry noise into the weak signals at the AFE.
I'll have to make sure to clean my scope the time I pull it apart.
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I'm on vacation and the weather isn't too nice so I've spent waay to much time hacking on my FPGA image. I've now managed to make the emulated DDR2 memory on the SoC bus read/write and can capture data from the ADC directly into the DDR2 memory attached to the scope.
http://blog.weinigel.se/2016/08/15/sds7102-ddr-capture.html (http://blog.weinigel.se/2016/08/15/sds7102-ddr-capture.html)
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I used the search on this thread and the forum, but couldn't see any results for my problem.
I got a SDS7102V and have no luck recording screenshots/waveforms onto USB sticks/flash drives.
Firmware version is 5.4
What happens:
I use the menu to save an image, insert the USB stick, hit [Save] the keyboard comes up on screen.. either scroll and go back to [Enter] or change the filename and go then to [Enter] or stay on [Enter].. once I press the multipurpose knob for starting the transfer action nothing happens.
If there was a light on the USB device it now goes dark, the screen keyboard stays on the display and nothing further happens (10+ minutes pass by). If I pull the USB stick out and check it for images, there is an empty (or several, depending how often I do this) bmp file in it with the name I set/chose via the on-screen-keyboard, but size is 0 kB).
Oh, and after I pull the USB stick the scope works again (after showing for some moment a little bar instead of the on-screen-keyboard).
Anyone seen such behavior on those units?
Any fix?
I checked their website with the scopes particulars and it tells me I got the latest fw for it..
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I used the search on this thread and the forum, but couldn't see any results for my problem.
I got a SDS7102V and have no luck recording screenshots/waveforms onto USB sticks/flash drives.
Firmware version is 5.4
What happens:
I use the menu to save an image, insert the USB stick, hit [Save] the keyboard comes up on screen.. either scroll and go back to [Enter] or change the filename and go then to [Enter] or stay on [Enter].. once I press the multipurpose knob for starting the transfer action nothing happens.
If there was a light on the USB device it now goes dark, the screen keyboard stays on the display and nothing further happens (10+ minutes pass by). If I pull the USB stick out and check it for images, there is an empty (or several, depending how often I do this) bmp file in it with the name I set/chose via the on-screen-keyboard, but size is 0 kB).
Oh, and after I pull the USB stick the scope works again (after showing for some moment a little bar instead of the on-screen-keyboard).
Anyone seen such behavior on those units?
Any fix?
I checked their website with the scopes particulars and it tells me I got the latest fw for it..
Have you tried an other USB stick ?
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I tried 2 different USB sticks and 1 SD card reader with 2 different cards.
I get empty bmp files written on them, but I essentially have to yank them out of the unit as there is no progress bar nor does it seem to finish (expected 35 seconds according to experience of others with this unit).
Just checked the manual from their site and see that they explicitly mention FAT32 with 4kB clusters.. well, seems I missed that in another online manual I checked earlier that wasn't directly from them were that wasn't mentioned at all.. |O
It's working and feels like 5 seconds only to me from hitting [save] via the multiknob till it's done writing with the progress bar.
The [copy] button under the multiknob still doesn't seem to do anything (as I have read on the interwebs), so no fault there I guess.
Thanks for your help. Much appreciated.
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I used the search on this thread and the forum, but couldn't see any results for my problem.
I got a SDS7102V and have no luck recording screenshots/waveforms onto USB sticks/flash drives.
ed their website with the scopes particulars and it tells me I got the latest fw for it..
Strange, my comment disappered, I might have had too many links in there.
Anyway, I think this is a known problem. The cluster size of the FAT file system on the USB drive must be 4 kBytes or smaller, large USB memories can have a cluster size of up to 32 kBytes. Google for "owon sds fat32 cluster size".
Try formatting the USB memory with "FORMAT X: /FS:FAT32 /A:4K" or "mkfs.vfat /dev/sdx1 -s 8 -F 32" on Linux.
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A question for other users of this scope:
I'm slowly getting back into electronics after a 3-year break. My scope was stored (in "normal" room conditions) unused for a while and now it developed a series of issues which are probably inter-related :-BROKE.
First thing I've noticed is that the MC34063A is getting quite hot.
The stock Chinese part had issues back when the scope was new. Basically, it would start switching, then stop at around 50% of transition, take a short break, drink a bit of coffee and then complete the switch. Changing the chip to an Onsemi part fixed the issue. For some reason I don't remember now, I also replaced the R33 current-limiting resistor with a short. Back when I was using the scope, things seemed to be working fine for at least 1 year if not more.
Now, on the other hand, the chip is getting really hot and is untouchable when the scope is connected to the PSU. After a while, it will stop working and the voltages on screen drift up to infinity. If the scope is disconnected from the PSU, the chip remains cool. A while later, the Onsemi regulator died completely, so I replaced it with another one. At the same time, I removed the short and put pins for a multimeter in its place. One thing I did notice is that when I have multimeter in series, it stabilizes the MC and the rest of the scope is using a varying amount of current that seems to drift between 3,5 mA and 5 mA. Of course, with such current, the regulator stays cool. If I replace the multimeter with a regular short, regulator gets hot again. The power supply is PCB-T115-J rev4. Unfortunately, I don't have another handy source of negative voltage, so I can't measure how much current the scope would like to take if there's no limiting from the MC.
The other issue I have is auto-calibration. Basically, the scope won't properly auto-calibrate and on some voltage ranges, the zero volts line has offset. I'm not really sure how to go around troubleshooting this thing. Also the rechargeable battery on the ADC board is at around 0.8 V. This is with the multimeter connected to the MC34063A's current limit pins. The ADC board is SDS1209 version.
The third issue is that vertical position adjustment is a bit jumpy. Basically, I'd adjust it in one direction and the line would go up and down and sometimes multiple steps for one step of encoder rotation. My gut feeling is that it's most certainly a bad encoder, but I thought I'd just mention it here for completeness's sake.
So does anyone have any ideas what could be causing any of the issues?
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The third issue is that vertical position adjustment is a bit jumpy. Basically, I'd adjust it in one direction and the line would go up and down and sometimes multiple steps for one step of encoder rotation. My gut feeling is that it's most certainly a bad encoder, but I thought I'd just mention it here for completeness's sake.
No idea about the other questions, but the jumpiness is just crappy firmware in the scope. All mechanical switches such as the ones in the rotary encoders are noisy and need some kind of debouncing. The firmware in the scope does a really bad job with debouncing and the position will jump. I have that problem with all rotary encory encoders on my scope even if some of them are worse than others.
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The firmware in the scope does a really bad job with debouncing and the position will jump. I have that problem with all rotary encory encoders on my scope even if some of them are worse than others.
Really?? Then I must have been lucky. I myself didn't have any jumpiness issues previously.
By the way, thanks a lot for the great work on firmware hacking!!
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By the way, thanks a lot for the great work on firmware hacking!!
Thanks. But I need to get back to it. A lot of things have happened (playing Satellite Reign and my job getting bought by Nokia) and I haven't had time to do any hacking on the scope for months.
I know how all about how the hardware works now, now I "just" need to build a usable firmware from it.
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Wingel, we have subscribed on your project with interesting, many of us!
Your job with 7102 is marvelous and you had many congrats for that!
We will wait for the fw update from you...
@AndrejaKo = The "jumping" on vertical position adjustment is as fw issue as rotary encoder fault, specially if the device had no working for long time (it is know issue).
2-3 weeks on daily operation in normal temperature room, will recover it enough but no 100%.
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Hello owon owners! I have a question to everyone who looked inside the scopes. I was replacing encoders, and decided to take a look to input stage of adc.
My unit use MXT2001, and channel 1 is a little bit different from channel 2.
Look at the marked part, ther is a some part marked 30A and a capacitor. and second channel do not have a cap.
First of all, why are they even there? And what ar they doing, cap maybe to limit higher frequency, but if 30A is a resistor, what the point to attenuate signal?
Not every 7102 based scope have them, if u look at diferent posts sometime ther ar resistor and cap at the adc input, sometimes not.
In my case i measure 70Ohms at both adc inputs instead of 100. So is that 30A a resistor?
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Yes, the smd 30A is the R230 resistor. It is marking with 30A, ie 200ohm.
I don't know why the above capacitor C83 is missing in your Owon.
Is that something to the final measurement (I doubt), but as I see at my Owon these are identical and there is no missing any capacitor !
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Good to see the amount of reverse engineering going on with this scope. For those who don't know the official OWON scope software has the ability to send commands via usb to control a large proportion of the scopes options. Unfortunately this is windows only and tbh the installer for the software seems a little questionable.....
Either way after a few hours with wireshark I have extracted most of the commands and have written a very basic proof of concept program to allow Linux (or any os that supports libusb1.0) to send and control the oscilloscope using a (very) basic command prompt interface.
I hope to one day create a QT interface to mimic the official owon app ( but better :) ) but progress may be slow based on work priorities etc...
For anyone interested in incorporating usb functionality into their apps, take a look at my usb_interface.c file to see the commands and important byte adjustments.
https://github.com/7oxicshadow/owoncontrol
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Either way after a few hours with wireshark I have extracted most of the commands and have written a very basic proof of concept program to allow Linux (or any os that supports libusb1.0) to send and control the oscilloscope using a (very) basic command prompt interface.
There's a specification for PC communication protocol: http://owon.fj0596.com/software/Application/SDS_Series_Oscilloscopes_SCPI_Protocol.pdf (http://owon.fj0596.com/software/Application/SDS_Series_Oscilloscopes_SCPI_Protocol.pdf)
http://www.owon.com.hk/service_down.asp?seek=SDS (http://www.owon.com.hk/service_down.asp?seek=SDS)
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I hope someone can help. I cannot get an image to a USB stick. it creates the file, but the file is blank and has no saved image. Is there something I am missing?
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I hope someone can help. I cannot get an image to a USB stick. it creates the file, but the file is blank and has no saved image. Is there something I am missing?
It could be that the USB drive is not formatted to FAT32 with allocation size of 4K or less.
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Does anyone know where to find the latest firmware for the E-series model of this scope, "SDS7102E"? All the firmware I find on various OWON websites specifically say that they're for the non-E models. My Google-fu is failing me.
I also wonder if it's possible to hack the firmware to enable the deep memory option. My version officially has up to 100K memory, but the memory chip attached to the FPGA is exactly the same chip as the regular version.
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No public firmware has been released for the -E version. You're stock with the factory installed version. I had one of those 7102-E models and it just crapped itself after a month of use. No support, no firmware update (or even the same firmware which was installed on the scope). Had to sell it to the same shop i bought the scope from at the 1/3 of the price. Yeah....
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Hi! Someone know what smps in the scope run at 60khz? I've got some spikes in the mv region and i want to try to find the source. Thanks!
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Hi! Someone know what smps in the scope run at 60khz? I've got some spikes in the mv region and i want to try to find the source. Thanks!
Are you sure these spikes are from the internal source? Please put a picture
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Quite sure, i have shut down every smps/flurescent/led lamp around here. Attach the photo of the usual test of the probe to the gnd test point.
Time ago wasn't present this ~50mvpp spike, only the ~20mv background noise.
Suspect some electrolytic capacitor that's going.
I've found on this thread that the -7.9v smps works at nearly 60khz, i think that can be the source.
I have already to dismantle the unit for the nasty rotary knobs... time to do some work...
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I had the same issue ages ago. In the end I just ripped out the S/Mode, made up my own, and even added a Li pack. Got rid of the 240V IP and made it universal DC
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Wow a lot of work :phew:
Did you have some photos or schematics?
You have done it linear?
Thanks!
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Na, it's a pretty simple circuit board to replace and as I needed it for mainly heavy vehicle electronics - 12-48VDC, it was a perfect solution.
I'd have to dig up old PCB circuits I made (could be a few days), but I used very low noise DC-DC converter, complete modules, so I knew the noise figures were the best I could get (Vicor I think, but I can check).
I had that same noise you posted, and for the very high sensitivity signal tracing (underground sensors), it was a disaster. All quite forward.
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:clap: thanks for the suggestion! I'll check those vicor modules.
The modules worked from 230v to the voltages needed for the scope, or you lowered them with a conventional transformer+diodes?
This scope had been always a bit noisy (i received it with 200mv pp spikes, after a first dismantling and a good clean lowered them to 20mvpp), and as if i need to dismatle it, it'w worth to made it a bit better.
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I checked vicor modules and... wow how much they costs :wtf:
For the same ammount i can buy a new scope :-DD
In any case i try to follow you suggestion and find suitable low emi modules (a bit cheaper :phew:)
Mean well encapsulated units seem interesting
I need to open the scope and check how much space there is inside..
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Where did you connect the probe? it seems to me this noise gets absorbed by the probe's ground lead, but if you see this noise without a connected probe, that's different
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Noise measured on the gnd of the probe calibration point (as common on this device. Internally the scope generates a lot of emi.
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I checked vicor modules and... wow how much they costs :wtf:
For the same ammount i can buy a new scope :-DD
In any case i try to follow you suggestion and find suitable low emi modules (a bit cheaper :phew:)
Mean well encapsulated units seem interesting
I need to open the scope and check how much space there is inside..
LOL. You don't need to use that specific brand / type. It was just one I use, of of many. New converters these days are pretty damn quiet (noise wise), and getting extremely efficient (if needed). My current favourite is T31SN24005, but there are so many others, for whatever price range you want.
If you need them even quieter, then just add LC filters / common mode filters / magnetics etc and you can even go linear. It worked perfectly for me, as I was in the same situation.
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Seem that i can't find that module over here in italy, i'll search something similar. You have replaced only the main psu or also some smps modules on the adapter board?
Thanks!
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Seem that i can't find that module over here in italy, i'll search something similar. You have replaced only the main psu or also some smps modules on the adapter board?
Thanks!
What is your oscilloscope full model?
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Mine is a 13xx s/n. It's already the "low noise version". But the 60khz noise developed recently. Before was only around 20mv, now 50/60.
Need to to choose from full linear (i not think to have enough space for diassipator), linear then smps (if i can fit a good toroid inside), or full smps (with low noise modules)
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Mine is a 13xx s/n. It's already the "low noise version". But the 60khz noise developed recently. Before was only around 20mv, now 50/60.
Need to to choose from full linear (i not think to have enough space for diassipator), linear then smps (if i can fit a good toroid inside), or full smps (with low noise modules)
Please put some images from the power supply unit. it might be some bulgy electrolytic caps there. if it was not noisy from the beginning, then it might be damaged. be sure to remove the on/off switch cap first and press it down before opening the case. once I broke the switch handle while I was opening the case, then I had to replace it.
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Seem that i can't find that module over here in italy, i'll search something similar. You have replaced only the main psu or also some smps modules on the adapter board?
Thanks!
It is also second sourced as I3A4W005A-150V, but it is just a suggestion. What I was trying to say though is -
As the DSO is a portable, I did NOT want any 120-240V IEC / mains in it AT ALL, so ripped all that out. I made a replacement plate with DC sockets and pluggable sockets, and now can power it / charge up the batteries from ANY 12V - 19V common power pack (ie from any PC), and in my case from ANY vehicle 12-48VDC (and now also PoE supplies). It is completely isolated from all mains.
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Thanks digsys, perfectly understood. Based on how much space i have inside i take my decisions.
hesam.moshiri, for sure it's an electrolytic cap that it's going, maybe replacing it i can remove the 50mv spike, but as i already take it apart, i'll try to made it a bit better.
Thanks!
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Someone can explain me how is possible that my device today had not ANY noise and was able to trigger well also a 20mv signal, while few weeks ago the background noise was more than 100mv?
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Someone can explain me how is possible that my device today had not ANY noise and was able to trigger well also a 20mv signal, while few weeks ago the background noise was more than 100mv?
Nearby SMPS ON ?
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Well, here's where you'll have to do some CSI detective work :-)
Was it plugged in and ON / charging / OFF ?
Was the battery full / mid / low ?
Was the device under test generating noise and being picked up from the test leads ?
What other S/S devices were on in the near vicinity ? Phase ? Have you gone from heating / cooling ? - usually a high draw.
There's NO reason to suspect, at this point, that the 2 instances of noise are related. Up to you to prove either way.
Good luck Columbo :-)
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In the past for trying to understand why all that noise i've moved this diabolic thing also outside the house, with no improvement. AFAIK nothing has changed, have the same things aroud (only added some instruments, nothing removed).
No battery attached.
The only thing is that now i leave the main switch on, and i use the top on/off button to turn it on. This result to have the green light powered on all the time.
Today i check if from really cold state has the noise, but in past i've already tried to leave it on without appreciable result.
If it remain in this way, i have no need to replace the smps for something less noisy, but i hate things that fix itselves, as have the tendency to broke itselves with same rapidity. I'll teardown it into little pieces >:D
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In the past for trying to understand why all that noise i've moved this diabolic thing also outside the house, with no improvement. AFAIK nothing has changed, have the same things aroud (only added some instruments, nothing removed).
No battery attached.
The only thing is that now i leave the main switch on, and i use the top on/off button to turn it on. This result to have the green light powered on all the time.
Today i check if from really cold state has the noise, but in past i've already tried to leave it on without appreciable result.
If it remain in this way, i have no need to replace the smps for something less noisy, but i hate things that fix itselves, as have the tendency to broke itselves with same rapidity. I'll teardown it into little pieces >:D
You might be very surprised where noise can come from.
My customer had a similar problem with his new SDS1104X-E and after some emails and phone calls the source was found to be a cellphone charger some meters away and behind a curtain and the mystery deepened when he did not know who it belonged to or when it got there !
Turned OFF and of course the problem was gone. :)
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All the chargers remained the same around the scope (and in the room). I have the scope at least from 6/7 years and was always noisy. Today i do some tests.
Maybe one of my neighbours had something transmitting at high power? Strange because the noise was at a switching frequency.
Need some test..
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... well, add to the fact that many users have reported a very similar issue in that scope, as have I, your job is made more difficult. Carry on Columbo :-)
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Hello,
I have a dedicated lab for my work 15km from the house.
When I received my previous oscilloscope, I was surprised by the noise.
I double checked my measurements, my probes, moved my oscilloscope.....nothing change. But at home everything was normal.
My lab is near a military zone....I don't know what they are doing there but we probably add to this a lack of shielding and we have the beginning of an explanation ;D
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While trying to reduce a bit the noise made by the smps, i've ordered some nichicon pw series capacitors (not the lowest possible esr, but i tought that maybe were better than original) to put in psu and adapter board. To my surprise, the chmec oem capacitors used aren't that bad. The 1000uF 16v (all tests done at 1khz with deere de 5000) are 0.039mohm while the pw are 0.061, while the 470uF 16v are 0.062 vs 0.117 of the pw. Now, worth replacing them? The original are 7y old, but very light use.
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The third issue is that vertical position adjustment is a bit jumpy. Basically, I'd adjust it in one direction and the line would go up and down and sometimes multiple steps for one step of encoder rotation. My gut feeling is that it's most certainly a bad encoder, but I thought I'd just mention it here for completeness's sake.
No idea about the other questions, but the jumpiness is just crappy firmware in the scope. All mechanical switches such as the ones in the rotary encoders are noisy and need some kind of debouncing. The firmware in the scope does a really bad job with debouncing and the position will jump. I have that problem with all rotary encory encoders on my scope even if some of them are worse than others.
For anyone with such problems, I was able to fix this with a couple of capacitors on the encoders:
https://www.eevblog.com/forum/testgear/owon-sds7102v-problem-with-encoders/msg3479200/#msg3479200 (https://www.eevblog.com/forum/testgear/owon-sds7102v-problem-with-encoders/msg3479200/#msg3479200)
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Has anyone found a way to flash a Chinese eds102 with sds7102 fw? Thanks
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Has anyone found a way to flash a Chinese eds102 with sds7102 fw? Thanks
I got EDS102CV stuck at logo boot loop, did you try to flash sds7102 firmware over eds102?
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Is there anyone who has a NAND flash dump for Micron 29F1G08ABAEA? Or, is it the same as Samsung K9F1G08?
Also, has anyone flashed NAND-flash using J-Link v8 for example? Or using LPT wiggler is a must? Thanks!