On Nov 18, 10:21*am, Grumpy The Mule wrote:
Howdy,

If the supply voltage to the oscillator changes, even though the
tuning voltage is stable, it may chirp or pull.

If the change is slow look for thermally induced changes like
You may not be able to feel this change with a finger. Applying
a bit more heat to suspected parts might indicate the culprit. *

Also look for changes in the voltage on large capacitors. It
wouldn't be unusual for bias voltages to change when the oscillator
starts up. *An extreme case of this is squegging.

73,
Grumpy

Thanks Grumpy. I'll check supply voltage next. It's not a thermal
problem. The output is nice and stable until key down when it pulls.
It's also frequency stable during keydown, just on a different
frequency. The oscillator isn't keyed, so I don't think it's an
oscillator startup issue.

73,
Kenn