[Amps] Mica cap substitute \ alternative

[Peter Chadwick]

Ian said:
> the derating above 5MHz may not be due to the 
mica at all. It could well be due to heating in the very thin 
metallization, which would  increase with frequency due to the skin 
effect.<
Wouldn't one get the same effect with ceramic caps, where the electrodes are similarly formed?
The old WW2 micas that Rich talks about were. I believe, mainly the 'stacked foil and mica' type, where the electrodes were relatively thick and so had  relatively high thermal capacity and heatsinking ability. So we can accept that they did get derated at frequency, but we don't have an answer as to why.
73
Peter G3RZP