Improvements in Owon SDS7102 HW/FW and some tests

[arekm]

AFAIK serial number (on sticker and in "about" menu) is like this - SDS71021209xxx:

SDS7102 - model
12 - year
09 - week
xxx - number in batch

so buy fresh unit.

[aghp]

SDS7102V
This time version is 2.8.2 and some note, related perhaps to HW.
I can not do real compare face to face with exactly all same with earlier version but it "looks like" signal capture quality have littlebit better or this is just normal random variations between single units.


Becouse someone have asked including also Owon name:

How slow is the image save speed of the DS2000-series compared to other scopes (Owon, Hantek..)?
I was surprised how slow these are compared to other (like Tektronix). If I recall correctly, on those more expensive models it won't take many seconds...

Some data about Owon.
Test: PC (IBM T42 and winXP SP3) USB  <----> Owon SDS7102V  (version 2.8.2)
PC running Owon Oscilloscope version 2.0.8.11
Test: Transfer  .BMP images to PC continuously, time 60sec. Result 48 images stored.
One bmp image (800x600x24) every 1.25s   
(of course waveform data is faster)

BMP image to USB memory stick. (Verbatim old and cheap 4G) Around ~5-6s

This is slow but need also remember that there need push first save button and then use defaul file name or edit it and then enter and  then start transfer and this time is looked here.
Maybe this time is not so meaningfull becouse there come also "human time".

If save "Wave" to usb stick it is more fast than my finger if use 1k memory and with 10M memory it takes  around 30s.
With 10M memory from scope sto PC using Owon PC software and USB connection it takes around 4 second.

[Hydrawerk]

Well, the Owon SDS scopes are OK, but do not forget the big disadvantage... It has low waveform update rate - only up to 33 waveforms per second. Please check Marmad's video at 26:46 http://youtu.be/eqcEi6ru4ZM?t=26m46s Probably they used a slow memory IC, or so...
Then, there are no tools to manage the huge 10MB memory, like mark or search.

[kape]

Becouse someone have asked including also Owon name:

How slow is the image save speed of the DS2000-series compared to other scopes (Owon, Hantek..)?
I was surprised how slow these are compared to other (like Tektronix). If I recall correctly, on those more expensive models it won't take many seconds...

Well, Kari/rf-loop/aghp - I hope that 'kape' from Finland - whose total of 3 posts in the Rigol DS2000 Review thread all mention or reference the Owon - is not another of your 'alter-egos' here on EEVBlog (or a close friend or relative), but it certainly wouldn't surprise me. In any case,  I'll leave that to the Admins here to sort out.

marmad, I can confirm that I have no closer relation to aghp. Please let's not try to start any war here:)
My old analog scope got broken and I was looking for affordable alternatives within this lower cost category of DSOs (including the two most interesting alternatives, SDS7102V from Owon and DS2072 from Rigol). As the user manual of either of these products won't tell you all the details, I was asking for details through this forum from users that actually own the device.
I found out that both scopes have their advantages. It just depends quite a lot of the application they are used for.

And thanks aghp for the BMP image save speed to USB stick. I think that I previously read somewhere that the Owon would take tens of seconds to save a single BMP-file to USB-stick. That was the main reason for asking further details about both oscilloscopes.

Still haven't decided which scope (SDS7102V or DS2072) is better for my needs....

PS. When discussing with aghp about the good and bad features of SDS7102V, I told him that my intended application also covers hunting fast digital signal glitches. He honestly told me that the Rigol DS2072 would maybe suit my application better than the Owon (instead of keep selling me the scope he has). That's what I value the most in salesmen!

BR,
Petri

[marmad]

marmad, I can confirm that I have no closer relation to aghp. Please let's not try to start any war here:)

Sorry, Petri - no offense intended. In any case, the war (more like a squabble) between aghp and myself had been going on awhile.

Still haven't decided which scope (SDS7102V or DS2072) is better for my needs....

If you don't plan to ever earn any money using the DSO - or you are on a really tight budget now and plan to upgrade in the future - or if you MUST have battery portability OR VGA output now - get the Owon.  If you want a better long-term investment, get the Rigol. As I've mentioned before - and I'm sure most people who've had both scopes in their hands would agree - there is no comparison in terms of design, features, and build quality. The Rigol costs 2 - 2.5x more than the Owon - but you get many times more than that in terms of value. I owned the Owon for about 5 weeks - and I knew everything about it in the first 7 days or so. I've owned the Rigol  about 10 weeks - and I'm still discovering new features or enhancements that I hadn't realized were there,

PS. When discussing with aghp about the good and bad features of SDS7102V, I told him that my intended application also covers hunting fast digital signal glitches. He honestly told me that the Rigol DS2072 would maybe suit my application better than the Owon (instead of keep selling me the scope he has). That's what I value the most in salesmen!

The only ongoing problem I had with aghp was that almost anytime anything negative about the Owon was mentioned (especially in the Owon Review thread I started), he would feel compelled to jump in and counter or mitigate the criticism. There are other dealers on this blog - who sell Rigols, Hanteks, etc - that don't do this - because they realize that even though they might actually be 'right' about something, the fact that they have a financial motive to be 'right' sometimes colors the issue.     

[tvicol]

Some small power supply modification I have implemented in my OWON.

I had same power supply noise problem as many have reported here, so I had a look and try to improve somehow this.
Inside flyback smps is very noisy and generate large amount of noise inside and outside of the oscilloscope.
Getting this in a shielding cage will be next step, but for now I had a look on capacitors.
Original ones are very poor quality with high ESR.
PS before modifications.

[tvicol]

and after.

[tvicol]

Original capacitors have been replaced with organic semiconductor, tantalum and low ESR Samwha.
Here is the ESR of original C18 - 100uF/16V.

[tvicol]

This was replaced with organic semiconductor one.
His ESR is 22 times lower.

[tvicol]

Original 470uF capacitors have been replaced with Samwha.
Here is original ESR.

[tvicol]

Samwha ESR and comparison between original and replacement.

[tvicol]

In final following capacitors have been replaced:
C9
C10
C11
C16 - replaced with tantalum
C20
C21
C22 - replaced with 330uF/400V (mounted in battery compartment)

[tvicol]

Measurement of V8.4P before and after.
50mV/div

[tvicol]

V-7.6 before and after.

[AndrejaKo]

Interesting procedure! Do you have exact part numbers of components you used? I can't read them on the photos.

I'm not sure how to interpret results of V8.4P. If both images are 50 mV/div, to me it seems as if there's no improvement. On the first image, we have noise of almost 3 divs and on the second we have also the noise of almost 3 divs, but it's shifted up a little bit. Could you please explain that in greater detail? I feel as if I'm missing something obvious here.

The -7.6 V rails looks great on the other hand.

[tvicol]

LED R before and after.

[tvicol]

Interesting procedure! Do you have exact part numbers of components you used? I can't read them on the photos.

I'm not sure how to interpret results of V8.4P. If both images are 50 mV/div, to me it seems as if there's no improvement. On the first image, we have noise of almost 3 divs and on the second we have also the noise of almost 3 divs, but it's shifted up a little bit. Could you please explain that in greater detail? I feel as if I'm missing something obvious here.

The -7.6 V rails looks great on the other hand.

I used what I had in my workshop.
Almost any brand name, low ESR/ESL cap will do a good job.
Rubycon ZL and Rubycon ZA are even better than Samwha.

Well, the improvement for V8.4P is quite low. All measurements are at 50mV/div (see down left button) with my 25years old oscilloscope. Still serving me well. 

Next step is to add few ferrite´s and try to isolate SMPS with some Al/Cu foil.

I have also upgraded the firmware and for the time been I have no more ground issues. :-)

That´s all for time been.
Hope this information will be useful to others as well.

[AndrejaKo]

Well do post results when you do all that. Good luck!

[StubbornGreek]

Great job. I'm curious how much the ferrites and shield will help. Thanks for posting your results.

[Giorg]

how can I check wich HW revision I have?

The scope has been updated to 2.8.2 from the vendor for sure.

serial is :SDS71021251013

thanks!

[rf-loop]

how can I check wich HW revision I have?

The scope has been updated to 2.8.2 from the vendor for sure.

serial is :SDS71021251013

thanks!

AFAIK this serial come out from factory with version 2.8.2

I have seen several (original factory) SDS71021246xxx and SDS71021251xxx  and in all these what I have seen version 2.8.2. installed in Zhangzhou factory.

[VanitarNordic]

I upgraded my SDS7102 to the 2.8.3 version. Upgrades for each model are available here:

http://www.owon.com.hk/down-en.asp?bigclassname=software_upgrading

[kozi]

I upgraded my SDS7102 to the 2.8.3 version. Upgrades for each model are available here:

http://www.owon.com.hk/down-en.asp?bigclassname=software_upgrading

Above site seems to be down. 
Is there any new URL for FW DL ? O0

[AndrejaKo]

You can try to download from from the Chinese site at http://www.owon.com.cn/service_s.asp?SortID_1=3&SortID_2=0 but currently, they want you to fill out a form before they give you access to the file.