Author Topic: UNI-T UTG932/UTG962 200MSa/s Function Arbitrary Waveform Generator  (Read 156913 times)

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Offline electr_peter

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Re: UNI-T UTG932/UTG962 200MSa/s Function Arbitrary Waveform Generator
« Reply #450 on: October 10, 2024, 03:40:30 pm »
I bought the UTG932E few days ago and while i was testing it out i noticed that when i turn on the output, first for about 200µs  waveform looks like a mess and after that it settles and looks okay.
Did i get a bad unit, or is this normal behavior for these cheap units?
I didn't see it happening in reviews.
Tested on UTG962E - there is ~200us of relay bouncing after any signal type turn-on. This is perfectly fine, similar to many other AWG's. Your scope picture is not quite correct (due to under-sampling of the signal) - actual signal should like a horizontal line (relay OFF) or square wave (line at top or bottom) (relay ON) - there should not be any significant "noise" or "diagonal" lines.

On UTG962E there are 2 additional rise/fall time settings in pulse screen. So UTG962E has something more over UTG932E than just max frequency. EDIT: settings are related to SQUARE/PULSE signal screen setup differences.
« Last Edit: October 22, 2024, 08:29:45 pm by electr_peter »
 
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Offline salomonander

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Re: UNI-T UTG932/UTG962 200MSa/s Function Arbitrary Waveform Generator
« Reply #451 on: October 12, 2024, 10:20:20 am »
Is there an option to show the level in dBm instead of volts?
 

Offline Slartibartfast

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Re: UNI-T UTG932/UTG962 200MSa/s Function Arbitrary Waveform Generator
« Reply #452 on: October 16, 2024, 02:55:57 pm »
Hi,

got a UTG962E delivered today. Did some first measurements with it generating a square wave signal. It looks to be broken, as it appears specs are violated.

In this forum, some people had done rise time measurements reporting in-spec values of 15ns. The specs say 16ns. I measure approximately 22ns! See first screenshot below, taken with a Siglent SDS2504X+ and 50cm RG58 connecting the devices.

The signals at 10MHz and 20MHz look correspondingly awful. At 20MHz the third harmonic is not visible anymore at all, just looking at the oscillogram it is not distinguishable from a pure sine signal. In a proper square wave, the amplitude of the third harmonic is down by a faktor of three (as compared to the carrier), which is almost 10dB. With the third harmonic at the specified bandwidth frequency (60MHz), there is another 3dB attenuation, so I expect -13dBc. What I measure, is -34dBc!

At 10MHz, the signal actually looks as if the third harmonic is only just a little bit beyond the bandwidth limit, that would be 30MHz. The third harmonic is down by -18dBc. This is roughly what I'd expect at 20MHz, so I thought at first, I got a UTG932E with wrong labeling. However, the rise time violates the specs even in that case. In addition to that, the 10MHz square has a massive second harmonic, which should not be there at all.

Am I mistaken about anything, or should I really diagnose the device as "broken"?
« Last Edit: October 16, 2024, 03:00:05 pm by Slartibartfast »
 

Offline wasedadoc

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Re: UNI-T UTG932/UTG962 200MSa/s Function Arbitrary Waveform Generator
« Reply #453 on: October 16, 2024, 04:14:18 pm »
Is there an option to show the level in dBm instead of volts?
Yes.
Correct answer is no.  See below.
« Last Edit: October 17, 2024, 12:46:39 pm by wasedadoc »
 

Offline wasedadoc

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Re: UNI-T UTG932/UTG962 200MSa/s Function Arbitrary Waveform Generator
« Reply #454 on: October 16, 2024, 04:25:11 pm »
Hi,

got a UTG962E delivered today. Did some first measurements with it generating a square wave signal. It looks to be broken, as it appears specs are violated.

In this forum, some people had done rise time measurements reporting in-spec values of 15ns. The specs say 16ns. I measure approximately 22ns! See first screenshot below, taken with a Siglent SDS2504X+ and 50cm RG58 connecting the devices.

The signals at 10MHz and 20MHz look correspondingly awful. At 20MHz the third harmonic is not visible anymore at all, just looking at the oscillogram it is not distinguishable from a pure sine signal. In a proper square wave, the amplitude of the third harmonic is down by a faktor of three (as compared to the carrier), which is almost 10dB. With the third harmonic at the specified bandwidth frequency (60MHz), there is another 3dB attenuation, so I expect -13dBc. What I measure, is -34dBc!

At 10MHz, the signal actually looks as if the third harmonic is only just a little bit beyond the bandwidth limit, that would be 30MHz. The third harmonic is down by -18dBc. This is roughly what I'd expect at 20MHz, so I thought at first, I got a UTG932E with wrong labeling. However, the rise time violates the specs even in that case. In addition to that, the 10MHz square has a massive second harmonic, which should not be there at all.

Am I mistaken about anything, or should I really diagnose the device as "broken"?
Your first photo has "20M" in the bottom left corner. Is the scope's 20M BW limit  turned on?
 
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Offline Slartibartfast

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Re: UNI-T UTG932/UTG962 200MSa/s Function Arbitrary Waveform Generator
« Reply #455 on: October 16, 2024, 06:50:24 pm »
Hi,

got a UTG962E delivered today. Did some first measurements with it generating a square wave signal. It looks to be broken, as it appears specs are violated.

In this forum, some people had done rise time measurements reporting in-spec values of 15ns. The specs say 16ns. I measure approximately 22ns! See first screenshot below, taken with a Siglent SDS2504X+ and 50cm RG58 connecting the devices.

The signals at 10MHz and 20MHz look correspondingly awful. At 20MHz the third harmonic is not visible anymore at all, just looking at the oscillogram it is not distinguishable from a pure sine signal. In a proper square wave, the amplitude of the third harmonic is down by a faktor of three (as compared to the carrier), which is almost 10dB. With the third harmonic at the specified bandwidth frequency (60MHz), there is another 3dB attenuation, so I expect -13dBc. What I measure, is -34dBc!

At 10MHz, the signal actually looks as if the third harmonic is only just a little bit beyond the bandwidth limit, that would be 30MHz. The third harmonic is down by -18dBc. This is roughly what I'd expect at 20MHz, so I thought at first, I got a UTG932E with wrong labeling. However, the rise time violates the specs even in that case. In addition to that, the 10MHz square has a massive second harmonic, which should not be there at all.

Am I mistaken about anything, or should I really diagnose the device as "broken"?
Your first photo has "20M" in the bottom left corner. Is the scope's 20M BW limit  turned on?

Oh, s**t.  |O
I guess you're right. I had a hunch there was something wrong, that's why I asked here.
Thanks a lot!
Tomorrow I'll redo the test. Properly, this time.

Cheers  Peter
 

Offline Slartibartfast

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Re: UNI-T UTG932/UTG962 200MSa/s Function Arbitrary Waveform Generator
« Reply #456 on: October 17, 2024, 09:51:16 am »
Hi,

got a UTG962E delivered today. Did some first measurements with it generating a square wave signal. It looks to be broken, as it appears specs are violated.

In this forum, some people had done rise time measurements reporting in-spec values of 15ns. The specs say 16ns. I measure approximately 22ns! See first screenshot below, taken with a Siglent SDS2504X+ and 50cm RG58 connecting the devices.

The signals at 10MHz and 20MHz look correspondingly awful. At 20MHz the third harmonic is not visible anymore at all, just looking at the oscillogram it is not distinguishable from a pure sine signal. In a proper square wave, the amplitude of the third harmonic is down by a faktor of three (as compared to the carrier), which is almost 10dB. With the third harmonic at the specified bandwidth frequency (60MHz), there is another 3dB attenuation, so I expect -13dBc. What I measure, is -34dBc!

At 10MHz, the signal actually looks as if the third harmonic is only just a little bit beyond the bandwidth limit, that would be 30MHz. The third harmonic is down by -18dBc. This is roughly what I'd expect at 20MHz, so I thought at first, I got a UTG932E with wrong labeling. However, the rise time violates the specs even in that case. In addition to that, the 10MHz square has a massive second harmonic, which should not be there at all.

Am I mistaken about anything, or should I really diagnose the device as "broken"?
Your first photo has "20M" in the bottom left corner. Is the scope's 20M BW limit  turned on?

Oh, s**t.  |O
I guess you're right. I had a hunch there was something wrong, that's why I asked here.
Thanks a lot!
Tomorrow I'll redo the test. Properly, this time.

Cheers  Peter

Ok, so here we go. With the scope bandwidth limit removed, the rise time looks good now. I measure slightly less than 15 ns now, which is clearly in spec and consistent with other people's measurements.

The bandwidth measurements using square wave signals did not improve that much, though. They indeed are more consistent with a 30 MHz device. In the 20 MHz output, the third harmonic is visible now, but still much weaker than it should be with 60 MHz bandwidth. The FFT quantifies it at -27 dBc, where theoretically -13 dB should be observed.

The 10 MHz measurement suggests the output of the UTG962E to be bandwidth limited to approximately 27 MHz, where it should be 60 MHz!
The harmonics go as
                          Expected                                 Excess
Harmonic    Frequency     (Theory)     Measured     Measured  Attenuation
                [MHz]        [dBc]        [dBV]        [dBc]         [dB]
      1           10          0,0        -33,6          0,0          0,0
      3           30         -9,5        -47,3        -13,7         -4,2
      5           50        -14,0        -60,6        -27,0        -13,0
      7           70        -16,9        -76,6        -43,0        -26,1
      9           90        -19,1        -97,0        -63,4        -44,3
which shows a nice, smooth roll-off with the problem of the -3 dB point being somewhere around 27 MHz. I would call that quite acceptable for a 30 MHz device, like the UTG932E, but, as I wrote, this one is labeled and sold as a UTG962E.

Can somebody else with a UTG962E reproduce these results?

Cheers  Peter
« Last Edit: October 17, 2024, 09:53:39 am by Slartibartfast »
 

Offline salomonander

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Re: UNI-T UTG932/UTG962 200MSa/s Function Arbitrary Waveform Generator
« Reply #457 on: October 17, 2024, 10:42:45 am »
Can you elaborate on where to find this dBm option? I expected it in the sine menu but i cant find it. Im also not able to update my firmware due to some MD5 file that is supposedly missing  :palm: anyone know what that means? Cheers
« Last Edit: October 17, 2024, 10:47:52 am by salomonander »
 

Offline wasedadoc

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Re: UNI-T UTG932/UTG962 200MSa/s Function Arbitrary Waveform Generator
« Reply #458 on: October 17, 2024, 12:27:53 pm »
The 30 and 60 MHz numbers (for 932 and 962) are the highest sine wave output frequencies. Not BWs of the instruments.  Harmonic content of the other output waveforms will be limited by the 16ns rise time.
« Last Edit: October 17, 2024, 12:30:05 pm by wasedadoc »
 

Offline wasedadoc

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Re: UNI-T UTG932/UTG962 200MSa/s Function Arbitrary Waveform Generator
« Reply #459 on: October 17, 2024, 12:45:11 pm »
Can you elaborate on where to find this dBm option? I expected it in the sine menu but i cant find it. Im also not able to update my firmware due to some MD5 file that is supposedly missing  :palm: anyone know what that means? Cheers
Apologies.  My previous answer was incorrect.  Instead of relying on my memory I've dug mine out and turned it on.  No dBm options.  See below for hopefully final answer of "yes, does have dBm setting".
« Last Edit: October 18, 2024, 09:18:08 pm by wasedadoc »
 
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Offline Slartibartfast

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Re: UNI-T UTG932/UTG962 200MSa/s Function Arbitrary Waveform Generator
« Reply #460 on: October 17, 2024, 02:24:11 pm »
The 30 and 60 MHz numbers (for 932 and 962) are the highest sine wave output frequencies. Not BWs of the instruments.  Harmonic content of the other output waveforms will be limited by the 16ns rise time.

So it seems to be.

I consider their way of specifying the instrument misleading. The value of 60MHz is not only mentioned in the sine wave specification, but in the general, or global, specification as well. For any other machine, that would mean the bandwidth of the instrument. In addition to that, set to 60 MHz sine, it achieves a rise time of 6 ns!

You're right, that with the spec of 16 ns rise time for square wave, with a little math it follows that the waveform cannot deviate from sine much anymore at 20 MHz. But, when I read a data sheet, do I have to perform all kinds of calculations to find out if what I read is actually consistent? If a rise time of 16 ns is consistent with what I read as a globally specified bandwidth of 60 MHz? Because only if I find out it is not, I would question if I interpreted everything correctly.

I may send the unit back, as it probably does not satisfy my (current) needs, while a 60 MHz device would have. Not sure if I'll buy UNI-T devices so easily again.

Cheers  Peter
 

Offline wasedadoc

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Re: UNI-T UTG932/UTG962 200MSa/s Function Arbitrary Waveform Generator
« Reply #461 on: October 17, 2024, 04:06:09 pm »
No promises but if you wait 24 hours I may be able to post some photo(s) of pulses from my 962. May help you decide if yours is actually faulty or within dubious spec.
 

Offline wasedadoc

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Re: UNI-T UTG932/UTG962 200MSa/s Function Arbitrary Waveform Generator
« Reply #462 on: October 18, 2024, 09:06:26 pm »
10 MHz square wave from UTG-962E into 50 Ohm load.
 

Offline wasedadoc

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Re: UNI-T UTG932/UTG962 200MSa/s Function Arbitrary Waveform Generator
« Reply #463 on: October 18, 2024, 09:12:44 pm »
10 MHZ square wave from UTG-962E into TinySA.  Span 0 to 60 MHz.

10 MHz fundamental. 30 MHz and 50 MHz harmonics.
 

Offline wasedadoc

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Re: UNI-T UTG932/UTG962 200MSa/s Function Arbitrary Waveform Generator
« Reply #464 on: October 18, 2024, 09:15:36 pm »
Can you elaborate on where to find this dBm option? I expected it in the sine menu but i cant find it. Im also not able to update my firmware due to some MD5 file that is supposedly missing  :palm: anyone know what that means? Cheers
Apologies.  My previous answer was incorrect.  Instead of relying on my memory I've dug mine out and turned it on.  No dBm options.
My original answer from memory was correct.  It does offer dBm setting.
« Last Edit: October 18, 2024, 09:20:05 pm by wasedadoc »
 

Offline 807

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Re: UNI-T UTG932/UTG962 200MSa/s Function Arbitrary Waveform Generator
« Reply #465 on: October 20, 2024, 11:26:26 pm »
...Can somebody else with a UTG962E reproduce these results?...

I get very similar results. The square wave rise time at 10MHz is around 14 - 15ns.

The sine wave output is very flat right up to 60MHz. No significant troughs or peaks.

The square wave harmonics are as shown in the attachments.

« Last Edit: October 20, 2024, 11:31:43 pm by 807 »
 

Offline salomonander

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Re: UNI-T UTG932/UTG962 200MSa/s Function Arbitrary Waveform Generator
« Reply #466 on: October 22, 2024, 10:46:53 am »
Thanks,
this is awesome news regarding dBm! Looking at my menu - do i have to update the firmware?
« Last Edit: October 22, 2024, 11:04:11 am by salomonander »
 

Offline wasedadoc

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Re: UNI-T UTG932/UTG962 200MSa/s Function Arbitrary Waveform Generator
« Reply #467 on: October 22, 2024, 11:20:47 am »
Thanks,
this is awesome news regarding dBm! Looking at my menu - do i have to update the firmware?
When you have the generator in the situation in your photo, start entering a level using a number button.  Does that not make the dBm soft button appear?
 

Offline salomonander

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Re: UNI-T UTG932/UTG962 200MSa/s Function Arbitrary Waveform Generator
« Reply #468 on: October 22, 2024, 11:44:55 am »
It does give me more options when entering a value. But not dBm. I guess i have to update Firmware.
 

Offline wasedadoc

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Re: UNI-T UTG932/UTG962 200MSa/s Function Arbitrary Waveform Generator
« Reply #469 on: October 22, 2024, 11:54:03 am »
It does give me more options when entering a value. But not dBm. I guess i have to update Firmware.
Post a photo of what yours displays when you try to get exactly the same state as my DSCN0178.jpg shows.
 

Offline wasedadoc

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Re: UNI-T UTG932/UTG962 200MSa/s Function Arbitrary Waveform Generator
« Reply #470 on: October 22, 2024, 02:47:19 pm »
It does give me more options when entering a value. But not dBm. I guess i have to update Firmware.
No, I don't think you need to update the firmware.  The generator knows that you cannot transfer power into a HiZ load, so does not offer dBm (which is power, not voltage) option in HiZ setting.  Change that setting and try again.

Also for future information remember that setting does NOT change the output impedance of the generator.  It is always 50 Ohm.  That setting changes the calculation to display the voltage or dBm across a load of the value you input.
 

Offline salomonander

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Re: UNI-T UTG932/UTG962 200MSa/s Function Arbitrary Waveform Generator
« Reply #471 on: October 22, 2024, 07:58:40 pm »
It does work now. Awesome. Thanks mate!
 

Offline vislavy

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Re: UNI-T UTG932/UTG962 200MSa/s Function Arbitrary Waveform Generator
« Reply #472 on: October 30, 2024, 06:43:52 am »
Hello!

Please help me find a firmware dump for the microcontroller (GD32F207xxx), which is in UTG932/UTG962.
 

Offline hp3310a

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Re: UNI-T UTG932/UTG962 200MSa/s Function Arbitrary Waveform Generator
« Reply #473 on: December 09, 2024, 04:26:26 pm »
I really like (to get myself) the OTG962E but I need +-8V sine output at 30MHz (16Vpp). From what I heard (in a thorough review by Kerry Wong

it should be possible to do when setting the output to HighZ mode.

In the datasheet it says under "Amplitude range"

" <=10MHz: 1mVpp to 10Vpp (50Ohm)"
" <=60MHz: 1mVpp to 5Vpp (50Ohm)"

which I find confusing because Vpp should be 20V and 10V, no?

Could an OTG962E user please confirm that one can output +-10V at >10MHz when in HighZ mode? Thanks!
« Last Edit: December 09, 2024, 04:32:56 pm by hp3310a »
 

Offline electr_peter

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Re: UNI-T UTG932/UTG962 200MSa/s Function Arbitrary Waveform Generator
« Reply #474 on: December 09, 2024, 06:03:42 pm »
You are misreading Vpp definition. Vpp means voltage swing from negative peak to positive peak, i.e. 10Vpp = -5V - +5V

I can confirm UTG962E outputs 10Vpp in HighZ load (up to ~15MHz, in higher frequencies reflections may reduce amplitude) mode and 5Vpp in 50Ohm load (to over 50MHz). 16Vpp at 30MHz is not available.

EDIT: emphasis on 50Ohm/HighZ at the load side
« Last Edit: December 09, 2024, 09:07:43 pm by electr_peter »
 
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