On Jul 19, 7:17*pm, Kenneth Scharf wrote:

Because at low power the effective load resistance of the finals is much
higher than it is at low does not match the
load to 50 ohms. *The Q of the network at resonance is off, I'm not sure
if it is higher or lower .... depends on where the loading capacitor
ends up. *Also on 80 meters the range of the capacitors is limited to
begin with....

Yup. I'm sure the difference in load resistance was at play.

Since my last post, I permanently replaced the aforementioned 68K Ohm
resistor (R402) with a 200K Ohm in parallel with a 100K Ohm. The
original carbon composition resistor had a resistance of 380K Ohms--
over five times its original value. That's the largest amount of
drift I've ever encountered.

Also, I now get grid current during key-down in CW and TUNE.

Thanks for all the help, guys.

-Dave, K3WQ