Heathkit Sine-Square Audio Generator Problem

[xtjacob]

Hello all,
I've acquired an old Heathkit Sine-Square Audio Generator (Model IG-18) with a bunch of old test equipment. I hooked it up to test it and I noticed it has a problem with the voltage staying constant. It seems that the frequency is pretty correct, but the voltage is fluctuating all over the place. Anyone ever worked on one of these and might have an idea what the problem could be?

Apologies for the awful oscilloscope picture. I couldn't figure out how to setup the trigger so it would show the fluctuating voltage.

[xtjacob]

Ok, I probably should have googled first. Turns out the Feedback potentiometer inside needed to be adjusted. Now that's its stable it appears to be ~40hz off on all the settings.