[ARC5] Questions about silver-mica capacitors

[Kenneth G. Gordon]

>     I have found several silver mica caps that either caused warbling or 
> just jumped at some temperature.

I have had a VFO which jumped 10s of Hz at random times. After much 
searching, I found it was caused by a 3 - 30 pFd ceramic trimmer which had 
silver "plates".

Replacement with an NOS cured the problem...at least for now.

At this point in my "radio" experience, there isn't a single component in any 
piece of vintage gear that cannot be suspect at times.

Ken W7EKB