Author Topic: Owon 14-bit USB scopes  (Read 5686 times)

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Offline agusugid

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Re: Owon 14-bit USB scopes
« Reply #25 on: February 07, 2023, 09:09:57 am »
Image attached
in 14 bit mode and 8 bit Mode

That is not 2 mV, it is around 200uV RMS which is more normal.....


This is amount of noise that, for instance, has Rigol DS1054Z (unlocked to 100MHz) that is an 8bit scope.
It is still not low noise but OK. Low noise would be quite less than 100uV RMS. There are quite a few inexpensive 8 bit scopes (Micisg and Siglent comes to mind) that have much lower noise than that.

So Owon is 14 bit but noise levels are at just OK-ish entry level 8 bit scope level.. And it is not even that inexpensive.

For general purpose work, DS1054Z (or Micsig or Siglent) would be better choice overall..

I never said that the noise is 2mV  ;D ;D
And for the noise, I compared it with other USB scope in this price range .... not the bench scope like siglent or rigol which I believe has lower noise.

Regards
Agus
 

Online 2N3055

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Re: Owon 14-bit USB scopes
« Reply #26 on: February 07, 2023, 09:37:09 am »
Image attached
in 14 bit mode and 8 bit Mode

That is not 2 mV, it is around 200uV RMS which is more normal.....


This is amount of noise that, for instance, has Rigol DS1054Z (unlocked to 100MHz) that is an 8bit scope.
It is still not low noise but OK. Low noise would be quite less than 100uV RMS. There are quite a few inexpensive 8 bit scopes (Micisg and Siglent comes to mind) that have much lower noise than that.

So Owon is 14 bit but noise levels are at just OK-ish entry level 8 bit scope level.. And it is not even that inexpensive.

For general purpose work, DS1054Z (or Micsig or Siglent) would be better choice overall..

I never said that the noise is 2mV  ;D ;D
And for the noise, I compared it with other USB scope in this price range .... not the bench scope like siglent or rigol which I believe has lower noise.

Regards
Agus

Well you did say it.. but never mind. We could have misunderstanding here.

In Eleshop Owon VDS6102A  is €322.31 +VAT..

My point is that is not really THAT low cost..

Rigol DS1102Z-E and Siglent SDS1202X-E are same price range and better in every respect. And Siglent SDS1202X-E will have 3x less noise... Both will be fully featured "real" scopes that are proven to be working really well. Siglent SDS1202X-E will also have good FFT with 1MPts..

Unless you got your Owon for half the price, it wasn't a good deal at all, in my opinion..


 
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Offline agusugid

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Re: Owon 14-bit USB scopes
« Reply #27 on: February 07, 2023, 10:23:04 am »
Image attached
in 14 bit mode and 8 bit Mode

That is not 2 mV, it is around 200uV RMS which is more normal.....


This is amount of noise that, for instance, has Rigol DS1054Z (unlocked to 100MHz) that is an 8bit scope.
It is still not low noise but OK. Low noise would be quite less than 100uV RMS. There are quite a few inexpensive 8 bit scopes (Micisg and Siglent comes to mind) that have much lower noise than that.

So Owon is 14 bit but noise levels are at just OK-ish entry level 8 bit scope level.. And it is not even that inexpensive.

For general purpose work, DS1054Z (or Micsig or Siglent) would be better choice overall..

I never said that the noise is 2mV  ;D ;D
And for the noise, I compared it with other USB scope in this price range .... not the bench scope like siglent or rigol which I believe has lower noise.

Regards
Agus

Well you did say it.. but never mind. We could have misunderstanding here.

In Eleshop Owon VDS6102A  is €322.31 +VAT..

My point is that is not really THAT low cost..

Rigol DS1102Z-E and Siglent SDS1202X-E are same price range and better in every respect. And Siglent SDS1202X-E will have 3x less noise... Both will be fully featured "real" scopes that are proven to be working really well. Siglent SDS1202X-E will also have good FFT with 1MPts..

Unless you got your Owon for half the price, it wasn't a good deal at all, in my opinion..

What kind misunderstanding did you mean? ;D ;D my post is still there to read. But yes, I agree, never mind.
I got mine about USD 280 incl. shipping. Curiosity does have its price  |O |O. Rigol 1054Z about USD 470 in local shop here.
I have bench scopes too, but don't think the bench better in every aspects compared to this USB scope. At least in portability and larger display the USB scope has its advantage.
For speed and simple measurement, this Owon scope is not lacking compared to entry level bench.
But in general if you have more budget and can afford bench scope like Siglent or Rigol, that's still a better choice in my opinion.

Best regards
Agus
 
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Offline jasonRF

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Re: Owon 14-bit USB scopes
« Reply #28 on: February 07, 2023, 12:37:21 pm »

Math function is available. You can do - + * / with both channels
FFT also availale, but I think Owon should not give the function as it so useless
That is an improvement.  The subtraction function is of course key for a lot of measurements, and also a place where the extra bits can really help.

I just looked through the manual on the owon site, and they haven't updated it yet to include the math.  Does it let you pick the size of the FFT?  Or does it work like on the vds3102, where you only get a 2k FFT so just 1k frequency points?  I usually find that I want a pretty long FFT to really get the information I am looking for, but even a 2k FFT can be useful.   

jason

 

Offline agusugid

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Re: Owon 14-bit USB scopes
« Reply #29 on: February 08, 2023, 05:43:27 am »

Math function is available. You can do - + * / with both channels
FFT also availale, but I think Owon should not give the function as it so useless
That is an improvement.  The subtraction function is of course key for a lot of measurements, and also a place where the extra bits can really help.

I just looked through the manual on the owon site, and they haven't updated it yet to include the math.  Does it let you pick the size of the FFT?  Or does it work like on the vds3102, where you only get a 2k FFT so just 1k frequency points?  I usually find that I want a pretty long FFT to really get the information I am looking for, but even a 2k FFT can be useful.   

jason

Attached the panel control for FFT. So Useless. Can not even show 1 khz from the channel 1 wave.
 
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Online 2N3055

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Re: Owon 14-bit USB scopes
« Reply #30 on: February 08, 2023, 07:37:17 am »

Math function is available. You can do - + * / with both channels
FFT also availale, but I think Owon should not give the function as it so useless
That is an improvement.  The subtraction function is of course key for a lot of measurements, and also a place where the extra bits can really help.

I just looked through the manual on the owon site, and they haven't updated it yet to include the math.  Does it let you pick the size of the FFT?  Or does it work like on the vds3102, where you only get a 2k FFT so just 1k frequency points?  I usually find that I want a pretty long FFT to really get the information I am looking for, but even a 2k FFT can be useful.   

jason

Attached the panel control for FFT. So Useless. Can not even show 1 khz from the channel 1 wave.

You have to make it sample at lover sample rate if you want it to show anything at all. This is common mistake. You have only 10 periods on the screen. Set timebase to something like 10ms/div, not 500us/div and see if something starts to show up. In general FFT won't show good results (even on good implementation) if you can see details of signal in time domain..
Play with timebase a bit.
But yeah FFT is not very good.
 
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Offline agusugid

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Re: Owon 14-bit USB scopes
« Reply #31 on: February 08, 2023, 12:19:53 pm »
Just realize that the software can not auto detect the peak freq and put it in the center of the window  |O. No autoscale at all in vertical or horizontal axis. |O
Have to manually slide the fft to find the peak freq.

As you said, the more samples, the better  :-+

8bits vs 14bits shows different fft result

Best Regards
Agus
 
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Offline jasonRF

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Re: Owon 14-bit USB scopes
« Reply #32 on: February 08, 2023, 02:07:51 pm »
FFT looks usable - and seems like it must be larger than 2k.     :-+

I see you are in peak detect mode.  I have only used FFTs in normal sampling mode on my scopes.  Given how oversampled you still are it might not matter too much, but does the FFT look much different in normal vs peak detect?  I would especially be curious whether it changed the levels if the 2nd and 3rd harmonics. 

Jason
 
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Offline agusugid

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Re: Owon 14-bit USB scopes
« Reply #33 on: February 09, 2023, 02:07:09 am »
FFT looks usable - and seems like it must be larger than 2k.     :-+

I see you are in peak detect mode.  I have only used FFTs in normal sampling mode on my scopes.  Given how oversampled you still are it might not matter too much, but does the FFT look much different in normal vs peak detect?  I would especially be curious whether it changed the levels if the 2nd and 3rd harmonics. 

Jason

Image attached. I think the difference is minimal.

Agus
 
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Offline agusugid

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Re: Owon 14-bit USB scopes
« Reply #34 on: February 10, 2023, 02:28:39 am »
Thermal imaging for VDS6102A after 30 minutes
Room temperature about 30C
ADC and FPGA are the hottest spot
« Last Edit: February 10, 2023, 02:30:24 am by agusugid »
 

Offline agusugid

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Re: Owon 14-bit USB scopes
« Reply #35 on: June 23, 2023, 02:37:31 pm »
Difference between 14bit vs 12bit vs 8 bit
 
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