UNI-T UTG932/UTG962 200MSa/s Function Arbitrary Waveform Generator

[Yuriy V.]

Hi, all! I have a question about the sync output when using the UT932E (UT900E/UT900 family) in sweep mode.
What is the maximum duration (minimal frequency) of the sweep period at which the generator is still producing a sync signal?

[wasedadoc]

Is it possible to save the waveforms designed in the device itself for later use?

No.

[kavehm]

Is it possible to have the same waveform from the two outputs of ch1 and ch2?
Ch1 and Ch2 have the same output waveform at the same time?

[wasedadoc]

Is it possible to have the same waveform from the two outputs of ch1 and ch2?
Ch1 and Ch2 have the same output waveform at the same time?

Yes.

[Yuriy V.]

Cooler for UTG900/UTG900E: 3x2510 5V with 3.5V pover (used two 4007).

upd: STL (zip) attached

[MTamer]

Hello all,

I have a problem setting up Virtual Control Panel of the UTG900 Series on my Windows 10. After the setup completes, and running the program I cant see the screen of the wave and the parameter.
Can you please help me with this?

[Fungus]

Is there any way to hack the 932 to a 962?

[tatel]

Link on the first post of this thread

[Fungus]

Has anybody accurately measured the rise time of the sync pulse from one of these?

[electr_peter]

Has anybody accurately measured the rise time of the sync pulse from one of these?

Sync pulse rise time is 1.09ns into 50Ohm. Square wave on CH1/CH2 is slower at 54.7ns.
However, sync pulse max freq is only 2MHz. With higher CH1 output frequency sync drops in frequency and skips some pulses.

[Fungus]

Sync pulse rise time is 1.09ns into 50Ohm. Square wave on CH1/CH2 is slower at 54.7ns.
However, sync pulse max freq is only 2MHz. With higher CH1 output frequency sync drops in frequency and skips some pulses.

Thanks!

I've been using my UTG to test oscilloscope bandwidth and I was wondering how high it goes. I'm not worried about max frequency.

1.09ns is good for about 400Mhz. 

[Mechatrommer]

1.09ns is good for about 400Mhz. 

963ps... 467MHz (0.45 / Tr) https://www.eevblog.com/forum/testgear/rigol-dho804-test-and-compare-thread/msg5124906/#msg5124906

[Fungus]

1.09ns is good for about 400Mhz. 

963ps... 467MHz (0.45 / Tr)

0.45 / 1.09ns = 412Mhz

[Dimitrius76]

Hello All. Сan anyone post the firmware for the GD32F207 microcontroller here? I had an unpleasant situation when the microcontroller was broken by static discharge when I opened device.

[kds]

Hi All,
I couldn't figure out what are the possibilities to drive this AWG from Raspberry.
I saw some great python projects but I am not sure this is working with Raspi.
For my own usage this would somehow overcome the impossibility to store permanently custom signals.

[rifkum]

Problem found?

Hey group,
I have noticed that on my UTG962 the output level drops by about 6 dB when AM Modulation is turned On
this seems to happen even if the depth of modulation is 0%

test conditions
generate 14 MHz output at say -33 dBm sine wave
Set modulation to AM, 1 KHz, Sine wave, 0% Depth

Then when you turn the "Mod" off and on the level out drops by ~6 dB
This does not seem to happen with other modulation choices.
I see the drop even when the modulation "depth" is 0% (effectively off)


I uesd a Rigol DSA815 spectrum analyzer and also an HF Receiver (when pushing into the HF receiver I inserted a 40 dB attenuator to simulate an S9 signal of -73 dBm)

This appears to be a problem in the firmware
Can anyone confirm?

Thanks
Dwight

[Fungus]

I had a similar problem and I solved it by changing the internal impedance setting.

[rifkum]

@Fungus,
I changed from 50 ohm to 75 then 16 then HiZ and still a big drop when I enabled AM Modulation... even if the modulation % was set to 0%

Do you know what you did to fix it?  Or did you confirm that it did fix it??

dm

[807]

I get the same 6dB drop on mine as well. Can't say I've ever noticed it before you mentioned it. Tried different LOAD settings, but it makes no difference.

[rifkum]

Thank you @807 for confirming!
I have submitted email support request to Uni-T and will report if I hear anything.
Also finally found a USA phone number and will call it tomorrow.

Note for others...
You only see a dB output level option if you have 50/75 ohm output enabled, for HiZ output you only see voltage options on Amplitude but you do still see the voltage drop by half from it's original level before turning on AM Modulation.

Thanks
dm

[seronday]

With a 100% amplitude modulation,  the level on modulation peaks is 6dB above the unmodulated carrier level.

When the generator output level is set to maximum, the output amplifier stage may potentially be over driven on modulation peaks.
Reducing the carrier level by 6dB can avoid this problem.

Regards.

[807]

With a 100% amplitude modulation,  the level on modulation peaks is 6dB above the unmodulated carrier level.

When the generator output level is set to maximum, the output amplifier stage may potentially be over driven on modulation peaks.
Reducing the carrier level by 6dB can avoid this problem.

Regards.

At 100% modulation the level on modulation peaks are 6dB below the carrier.

This generator is capable of +17dBm when set to 50 Ohm load. So is well below it's maximum output when checked at -33dBm. I even tried it at it's lowest output setting of -56dBm, and again the output dropped by 6dB when AM modulation at 0% was turned on. However, the reading on the generator doesn't change, despite the 6dB drop on the spectrum analyzer.

The power in each AM sideband is 6dB down on the carrier, so for both sidebands added together there's 50% extra power in the signal. Perhaps the 6dB drop is a "blanket" approach to ensuring that the generator doesn't get overdriven if the carrier is set to maximum output with 100% modulation. The amplitude reading on the generator should decrease to indicate this though, which it doesn't.

[seronday]

With 100% amplitude modulation, the output voltage level on modulation peaks is twice the unmodulated level.
The UTG900 generators are specified to provide up to 10Vp-p into a 50 ohm load.
So to achieve this , the unmodulated carrier level needs to be reduced to 5Vp-p. (6dB drop).

This is mentioned in the UTG900 series User Manual near the top of page 16 on the copy that I have.

Regards.

[807]

With 100% amplitude modulation, the output voltage level on modulation peaks is twice the unmodulated level.
The UTG900 generators are specified to provide up to 10Vp-p into a 50 ohm load.
So to achieve this , the unmodulated carrier level needs to be reduced to 5Vp-p. (6dB drop).

This is mentioned in the UTG900 series User Manual near the top of page 16 on the copy that I have.

Regards.

Yeah. Sorry. I got hold of the wrong end of the stick 
I was refering to the sidebands as seen on a spectrum analyzer, but of course, if you look on the voltage envelope on a scope, then the 100% AM p-p waveform will be twice that of the unmodulated carrier.

With a dedicated RF generator, like my Marconi 2024 which has a maximum RF output of +13dBm, the output will drop to +7dBm if AM modulation is turned on. But this only applies to signals over +7dBm. At signal levels below this, the display on the generator & the output on the analzer remain the same.

The problem with the UTG962E is that the output is reduced for all output levels, whether they are near to maximum or not. OK, I can live with that, but the amplitude reading on the front panel should reflect this reduced level. You shouldn't have to remember to take 6dB off the reading when switching on AM.

[rifkum]

Thank you @Seronday!
So if my feeble mind comprehends your post...

I should have RTFM!
This is normal and expected behavior.

Would it not have been best if firmware showed that the level was now 6dB lower (or half voltage) so the user could make adjustments back to the desired level?
Or at least flash a warning  that the level has been reduce by 6dB when AM Mod is enabled?
Even better would be to boost the output by 6dB so user gets the expected level out... And then IF the user tried to boost the level past the unit capability it would warn that the max output is reduced when AM Mod is enabled

I'm curious if others with different brands of RF sig gens see this same behavior.
I have an old IFR radio service monitor and it does not exhibit this 6 dB drop when AM modulation is enabled.

Thanks for your reply!
dm