[Lowfer] Question on building homebrew variable caps...

[Bill Ashlock]

Ralph,

> > consider a set of fixed cap plates separated by glass plates
> > now sliding the glass in and out between the plates will make
> > the cap vary. Advantage would be a cap with good mechanical
>
>Glass is a very lossy dielectric at RF.  Ask the guys who build Tesla
>Coils.  I have popped more glass plate caps than I want to think about.
>Much better is PVC plastic.

Are you sure that glass is lossy at 185KHz? Or is it just the way that these 
glass plate capacitors are constructed - allowing uneven heat generated from 
the metal plates to crack the glass. PVC isn't that great either. Ask the 
guys that build the really high-Q loading coils.

Bill A

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