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

[lemon]

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.

[inlet]

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.

[TomC]

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!

[Carrington]

I don't know if my SDS8102V has the same fault. I don't even use it and now is completely disassembled.

[inlet]

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.

[Evi]

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.

[TomC]

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.

[Carrington]

I really have the desire to do a ritual, and throw it into the fire. 
I put it for sale, and nobody wants it, and no wonder.   

[Evi]

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.

[Carrington]

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€.

[av3ng3r]

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.

[inlet]

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.

[TomC]

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

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!

[Filip Jukic]

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

[TomC]

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.

[lemon]

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

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?

[inlet]

Have any respond from the Owon's support, about this?

Owon's support promised for 4 weeks to produce the new firmware.

[lemon]

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.

[TomC]

If nothing else, I would love to see this issue with the invert fixed. Anything else would be icing on the cake!

[Filip Jukic]

I have probelm with FFT, everything is described on this forum http://owon.forumup.com/viewtopic.php?t=216&mforum=owon
What you think about this? Should i report this to owon?

[TomC]

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

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.

[lemon]

New Oscilloscope PC Software version 2.8.20 from the Owon's main site.
No any reference for improvements about, no any changed log.

[TomC]

I noticed the Splash Screen is different, Owon instead of DS-Wave. Other than that, I haven't detected any changes so far.

[lemon]

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

[TomC]

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.