B&k 3010 function generator

[Bigdrums]

The sine, square, & triangle waves produced by my unit are not a steady frequency. Viewed on the o-scope they have a slight compression/expansion effect and prevents me from making the adjustments shown in the manual.
Anybody care to offer a possible solution?

3010_manual.pdf

[Enzo]

Can you hear this? Any chance it is a triggering issue on the scope?

Are all the power supplies CLEAN, and up to voltage?

The manual is nice, but there is no schematic in it that I see.

[Bigdrums]

Yes I can hear it pulsing, and only at a certain freq position does it clean up at all.
I measured the voltage supply's to the LM324 chips.
1 measures +24v, and - 5v, the other is -20v and +5v
I suppose therein lies the problem, as they should be similar and more less equal I think.
I'll try tracing the circuit back to see if I can find what's wrong.
Be great to have a schematic but I've had no luck finding one.

[Enzo]

See if that -20v line has excess ripple on it. You might have a beat frequency happening between signal and ripple.

Did you google B&K 3010? I just did, and first hit at the top was the Boat Anchor Archive, which included your schematic.

http://bama.edebris.com/download/b&k...schematics.pdf

[Bigdrums]

Thank you! Indeed that was the problem and after changing the cap, was able to make the calibration. All good
Thanks again!

[Enzo]

Almost like I had super powers...

[g1]

Doesn't seem too far-fetched. Clearly you can already fly, with much grace and elan.

[Enzo]

Have you seen Grace lately?