[R-390] Z-503

[dog]

Re: Z503, don't know if youse guys remember not long ago I had a problem 
with shifting gain with warmup. Turned out is was either or both C559/60 
in T501. It's the same type can as Z503. I replaced the ones I had with 
new dipped mica (I think they were 200pf) and got rid of the problem. 
Somewhere I read that the age of these postage stamp micas are now 
deteriorating because of their age and it just may be time to go into 
all those transformers and replace those micas. Shotgun. None of them I 
think are that hard to get to by just removing the can and replacing the 
caps, although there may be an issue with getting a soldering iron in 
some places.

Dave N3DT