AWG performing very poorly on new 2204A unit

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Ben_Cemlyn
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AWG performing very poorly on new 2204A unit

Post by Ben_Cemlyn »

Hi All

Just got my 2204A and been using it a few days. Very impressed with overall quality of hardware at the price, but the signal generator is performing poorly and unreliably. The pp voltage is way out (lower) than the set value and has continued to decrease in use (verified on other equipment). it is also noisy. Attached is image

There seems to be a fundamental hardware problem with this. Unless any suggestions I think I should exchange this unit (bought from cpc farnell, UK).

Comments please! :)
Attachments
pico sig gen problems.jpg

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Maks
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Re: AWG performing very poorly on new 2204A unit

Post by Maks »

Did you use the switch on the probe x1 - x10, and in the program picoscope 6 is in the settings for each channel?

Ben_Cemlyn
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Re: AWG performing very poorly on new 2204A unit

Post by Ben_Cemlyn »

Hi Maks

Yes, the probe is set to 1X.

When you say "and in the program picoscope 6 is in the settings for each channel?" can you tell me exactly where these channel settings are please? The scope seems to be working fine so it is not a problem with the scope or probes, its the output of the signal generator.

Thanks, Ben

Martyn
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Re: AWG performing very poorly on new 2204A unit

Post by Martyn »

Can you post a psdata file for this capture, and a picture of your setup, then we can take a look at what may be going wrong.
Martyn
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Maks
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Re: AWG performing very poorly on new 2204A unit

Post by Maks »


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Maks
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Re: AWG performing very poorly on new 2204A unit

Post by Maks »

If the reason is different, you can try to reprogram the oscilloscope - if you can't fix the cause, then the problem is in the hardware.

bennog
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Re: AWG performing very poorly on new 2204A unit

Post by bennog »

Can you also post a photo of your setup, to show you don't have a load on the generator.

ex a 50 ohm or 75 ohm attenuator.

Benno

Ben_Cemlyn
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Re: AWG performing very poorly on new 2204A unit

Post by Ben_Cemlyn »

Hi Martyn and all

Here is an example psdata file (for 2V sin from the AWG). The AWG is running directly into the scope without any other load, so a very high load impedance - a photo of this will not show any other information, but I can generate a photo if you really want ! :) . I have used the AWG with audio amplifiers, with a minimum imput impedance of several 10s of Kohm, never into a low load.

Regards, Ben
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sin example pico awg to scope in.psdata
(12.08 KiB) Downloaded 24 times

Martyn
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Re: AWG performing very poorly on new 2204A unit

Post by Martyn »

I have tried your settings and they work as expected, if I enable Resolution Enhancement at 12bits I get similar results but your file does not show this as enabled. So a photo of the setup, and one showing the back of the scope with the serial number label, would be good.

However it does look like there may be a fault that will require you to return it to CPC for exchange.
Martyn
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Ben_Cemlyn
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Re: AWG performing very poorly on new 2204A unit

Post by Ben_Cemlyn »

HI Martyn

Attached is a pic of the set up for the AWG test (as I said, nothing to show really! :) ), a pic of the rear of the unit and some screenshots for more tests I've just done (into scope only, no other load).

For the tests I've just done the unit is performing rather better at 1KHz then it did previously (now about 2.2V p-p), and increases with frequency but the p-p voltage decreases at lower frequency. Selecting DC coupling for the scope does not (and should not) affect the lower frequency response.

As per previous remarks, the performance at 1KHz was not right straight out the box (AWG into scope, no other load), and it has veen variable since (tested into scope only, or into source of many 10s of KOhm input impedance). I've never tried it with a lower load than this but can't see a reason why this should help...?

I think we've both spent some time on this now and its time for a decision soon so I can get myself a solid unit.

Thanks Martyn - regards, Ben
Attachments
screenshots 10Hz to KHz.jpg
IMG_20220610_130624.jpg
IMG_20220610_130513.jpg

bennog
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Re: AWG performing very poorly on new 2204A unit

Post by bennog »

Try a cable directly from the AWG output to the scope input.

Now I see a grey AWG output probe to a crock clip disappearing and then a BNC connector coming back.

Benno

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