Hello Ian,
I agree with the comments on the relative performance of an unknown
ceramic
mix at micro wave, but, up to 30 Mhz, I would have thought, would be ok,
however, one has to give the man full marks for his initiative .....this could
lead to enthusiastic people making their own ceramic switches, on the lines of
the TU unit type, or, producing the appropriate ceramic supports for the fixed
vanes in home brewed wide spaced variable capacitors.....as opposed to using
glass marbles!!!
I will certainly look into the possibilities, and may even have a go
myself.
I am sure that there must be a pottery trade "bible" of ceramic mixes, for use
at different frequencies, the clays must have a minimal metalic oxide content,
of course .......but the mechanical stability, under hot wire conditions is
one very good reason for using ceramic.......sincerely, John. G3JVC.
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