REVIEW - Owon SDS7102 - A look at the SDS series from Owon

[aghp]

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.

[kaz911]

Mine 8202 seems like the new version: Serial SDS82021143xxx
Got LAN and different VGA cabling compared to other tear-downs of 8102.

[muvideo]

Another curiosity:
what can be done trought LAN port?
Is it only useful with owon's software?

[rf-loop]

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).

[muvideo]

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.

[rf-loop]

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.

[Muxa52]

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:

[rf-loop]

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.

[cex]

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).

[rf-loop]

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!

[cex]

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.

[rf-loop]

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)

[rf-loop]

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.

[cex]

I'll check... thank you.

[kaz911]

I think these images shows the problem

[rf-loop]

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.)

[kaz911]

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.

[cex]

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?

[rf-loop]

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".

[nkcelectronics]

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

Will be adding more models the first week of January 2012 (SDS8102, SDS8202, HDS, PDS).

NKC Electronics

[cex]

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.

[rf-loop]

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...

[cex]

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.

[rf-loop]

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

[ForceFed]

Looks like my unit will be going back to be serviced/updated.
Also, noise on my unit only appears on channel one.