Hello all,

Can someone explain to me the mechanism of how a VFO "pulls" during
transmit? I have a transmitter circuit I've breadboarded, ugly
construction style, and the VFO will pull up ~2kHz with the key down.
The transmitter circuit is borrowed almost verbatim from the K1SWL
SW40+ transceiver.

I've checked the following:

1. dropped off the driver and final amp circuit with no change in
behavior
2. the tuning voltage to the varactor in the tank circuit does not
change during keydown.

I know there could be several answers here. What should I be looking
for?

Thanks to all,
Kenn
KA5KXW