[R-390] Gain drift

[dog]

It's not over yet. I just turned on the rx after being off overnight and 
fed 150uV into the IF section, and after a few minutes got -1.5V on the 
diode load, measured the RF on grid and plate of V504 and it seemed 
pretty low. I touched the plate with the mV meter, there's a snap and 
the gain jumps up about 10dB and the DL goes to -7V, where I'd set it 
last night. Then right away it starts drifting back down to where it was 
while I had the mVmeter on the plate, I watched it go down. Still 
something not right in that circuit. I did take off the cans to the 
other two IF interstage transformers and they look normal with the 
proper resistors and caps.

How does one know if a rx is supposed to be stagger tuned or not in the 
IF strip. Apparently there are 2 kinds. I tried stagger tuning T501 and 
T502, but it seems like 467 and 448KC is barely available at the DL 
where 455 is. I need to get the 2KC filter in my other IF module fixed 
and put that one back together. I may work on that today.

Dave N3DT