[R-390] R-390A IF deck caps in T501 or T502

[Dog T]

I was working on this issue last spring/summer. It took me quite a while and it was all described in my thread 'Gain Drift'. I used a Boonton (really a Moto) millivolt meter to start measuring gains along the IF tubes and found that between T502 the input was good, but the output changed. Could find no problems with tubes or voltages, although I did not check all the voltages, but I did narrow it down to T502. I just got sorta burned out at that point and let it go for a while. Then I see Larry's post. So I happen to have some 500V dipped SM 200pf Caps (4 of them) and I'll put them in T502 and report back when I get motivated. 
It was a bear to troubleshoot because it only happens when leaving the RX off for quite a while and then the gain changes within a few minutes of turn on. It's very noticeable though. 
Larry, did you change the caps in situ? It would be a real pain to take out T502, and maybe that's why you changed both of them. How would one know which one was bad? 
Some of my messages to the list are still not going through, I can't figure it out. 
Dave N3DT