REVIEW - Owon SDS7102 - A look at the SDS series from Owon - Page 1
Forum section: electronics / testgear

author: marmad
author_rank: Super Contributor
timestamp: August 08, 2011, 01:05:42 pm
content: 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 outmy impressions of the Rigol DS2000 series.Meanwhile, here is my Owon review - please watch the entire thing for both pros and cons:

author: patb
author_rank: Regular Contributor
timestamp: August 08, 2011, 02:00:24 pm
content: 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

author: Bren
author_rank: Contributor
timestamp: August 08, 2011, 04:59:15 pm
content: 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

author: tinhead
author_rank: Super Contributor
timestamp: August 08, 2011, 05:45:23 pm
content: 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 goti 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 bugsor sometimes really useless - on the other side, hmm, for Tekway it was first multilanguage-enabled scope, beforethat they did only chinese menu (so maybe an excuse, but only maybe). Later they finally managed to madenice working firmware (at that time i decided to post anything about them). Few months later Hantek shareholderbought 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 decisionabout 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 thereis 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 scopesand 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 updatesonly via email, Tonghui too, Tekway actually the same (Hantek is publishing the fw on website)Anyway, let's start the review

author: marmad
author_rank: Super Contributor
timestamp: August 08, 2011, 07:20:13 pm
content: QuoteYes, 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?

author: saturation
author_rank: Super Contributor
timestamp: August 08, 2011, 07:54:02 pm
content: Looking forward to the review too. Thanks for making this available. Hope you can post as many photos as you can.

author: bertchai
author_rank: Contributor
timestamp: August 09, 2011, 07:06:19 am
content: 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.

author: marmad
author_rank: Super Contributor
timestamp: August 09, 2011, 08:21:55 pm
content: Here's the first part - a look at the packaging, general design, and overall build quality of the unit:Edit: See First post.

author: tinhead
author_rank: Super Contributor
timestamp: August 09, 2011, 08:56:47 pm
content: 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 plusButtons - big minus, construction and type of buttons, just ugly. I would probably replace them by softer buttons ...

author: bertchai
author_rank: Contributor
timestamp: August 10, 2011, 01:54:27 am
content: 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

author: Mechatrommer
author_rank: Super Contributor
timestamp: August 10, 2011, 03:22:10 am
content: nice review Mark.

author: Bren
author_rank: Contributor
timestamp: August 10, 2011, 03:29:09 am
content: 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.

author: Nermash
author_rank: Frequent Contributor
timestamp: August 10, 2011, 06:39:43 am
content: Great review, looking forward to seeing part 2.Any thoughts on waveform update rate and frontend/adc noise level?

author: saturation
author_rank: Super Contributor
timestamp: August 10, 2011, 01:07:20 pm
content: 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.Quote from: Nermash on August 10, 2011, 06:39:43 am

author: marmad
author_rank: Super Contributor
timestamp: August 10, 2011, 02:23:30 pm
content: 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 yetThe 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 -poorless-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.

author: patb
author_rank: Regular Contributor
timestamp: August 10, 2011, 02:27:06 pm
content: 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?

author: tinhead
author_rank: Super Contributor
timestamp: August 10, 2011, 03:56:10 pm
content: Quote from: marmad on August 10, 2011, 02:23:30 pmright, but this makes only sense when the input stage/bw filter is really allowing to have a benefit. For example a cheap60MHz Tonghui DSO (with -3db on 75MHz) when sampling with 400MSs can show perfectly 300MHz signals in equivalentmode (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 reallyworking as expected. So well, is it importnat? Depends, i can work with avg sampling too.Quote from: marmad on August 10, 2011, 02:23:30 pmi 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.Quote from: marmad on August 10, 2011, 02:23:30 pmthe 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.

author: Unknown
author_rank: Unknown
timestamp: August 10, 2011, 04:17:16 pm
content: Quote from: marmad on August 10, 2011, 02:23:30 pmTry 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.Quote from: marmad on August 10, 2011, 02:23:30 pmSeems 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.Quote from: marmad on August 10, 2011, 02:23:30 pmApart 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.

author: marmad
author_rank: Super Contributor
timestamp: August 10, 2011, 07:01:47 pm
content: QuoteQuoteWell, 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.QuoteStrange, 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.

author: tinhead
author_rank: Super Contributor
timestamp: August 10, 2011, 08:52:23 pm
content: Quote from: marmad on August 10, 2011, 07:01:47 pmyeah "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 implementedas user selectable option, that's 10 lines in code.Quote from: marmad on August 10, 2011, 07:01:47 pmso you did single shot, zoomed out and the visible record length is 10ms when in single chan modeand 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 resultingin exact the same record length.

author: saturation
author_rank: Super Contributor
timestamp: August 10, 2011, 09:04:22 pm
content: 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: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:Quote from: marmad on August 10, 2011, 02:23:30 pm

author: Mechatrommer
author_rank: Super Contributor
timestamp: August 10, 2011, 09:27:54 pm
content: Quote from: saturation on August 10, 2011, 09:04:22 pmhow do you produce that clean 75MHz signal out of 3x25? what factory software?

author: marmad
author_rank: Super Contributor
timestamp: August 10, 2011, 11:12:55 pm
content: Quote@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.QuoteSure, for most things, but if you need to log data over time, it can be a godsend.Quote@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.

author: saturation
author_rank: Super Contributor
timestamp: August 10, 2011, 11:32:40 pm
content: 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 InvertCH1 On 50.0mV/ 16.0mV DC Off OffAnalog Ch Impedance ProbeCH1 1M Ohm 1XTime Time Ref Main Scale DelayMain Center 5.000ns/ 0.000000sTrigger Source Slope Mode Coupling Level HoldoffEdge CH1 Rising Auto DC -16.0mV 500nsAcquisition Sampling Averages Memory Depth Sample RateAverage Realtime 256 Normal 500.0MSaMath Source Window Display Screen ScaleFFT CH1 Rectangle Full 10.0mVrms/The last two images are your software with averaging, and without averaging but at 100 MHz.Quote from: Mechatrommer on August 10, 2011, 09:27:54 pm

author: bertchai
author_rank: Contributor
timestamp: August 11, 2011, 01:37:10 am
content: 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.....