Simpson 420 function generator (also wavetek 420)

[Filippo52]

I found an old signal generator and since it turns on I tried to get it working again regularly.
Everything works but the waveforms have a very strange shape, especially the sine wave.
I wanted to ask if anyone has a service procedure for calibrating the various trimmers in the generator.

I found a schematich diagram which I am attaching together with a photo of the apparatus

[wasedadoc]

If all the waveshapes are wonky first suspect would be the output stages, Q7 onwards.  Check the signals going into there by scoping the slider of that pot at Q7 base.

And check all the supply rails.

[wn1fju]

Didn't you ask about calibrating the Simpson 420 back in a thread you started on April 10, 2023?   Someone replied to you back then with a description of what the pots do and how you should adjust things.

[floobydust]

If there are defective components, you can't calibrate a "fix" it's a waste of time.  Troubleshoot first, calibrate last.

[Filippo52]

There are no shaky waveforms, they are all stable. It is the shape that is wrong, the sinusoid does not look like a sinusoid, the square wave is not symmetrical.
However I have found the address of the manufacturer who has responded satisfactorily.
Thanks anyway

[Filippo52]

I don't think there are any faulty components; I just think it's out of tune.
Thanks for the advice anyway

[Filippo52]

Yes, you're right, I missed that thread.
However, in the meantime the manufacturer, indeed the technical office managed to get me a precious document with the calibration procedures, which I now share immediately to make up for the double article
I hope they will be useful to someone

I inform you that I have the highest quality uncompressed copy and also a cropped and improved copy of the user manual.
However, both are too bulky for the site, if you are interested, ask me and I will put them on google drive

[alm]

You could upload all documents to one or more of these manual sharing sites:
KO4BB
xDevs.com
BAMA

[Filippo52]

done; i put the document in Bama,
However if someone are interested, ask me and I will put them on google drive