Why did you make your SDS7102 reviews on youtube private?
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.
That reminds me of the school kid who takes his ball home when things dont go his way.
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/), 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):
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:
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...
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
bad probe:
for my probe defect, they said they will ship me a replacement ...
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 commentsMaybe 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
Actually, I know how to manually adjust oscilloscope without Autoset button , but I just want to test my SDS7102 for first time.
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).
If this change occurred by design , I think it is very mistake.
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
I think I'd want to see if I could get an exchange myself.
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
A new software bug?
It is happened when I use Autoset button and CH 2 floated, CH 1 connected to circuit.
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
...But it IS stable
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.