Re: Carbon fiber mast - Radio transparent?

szekeres@xxxxxxxx (GregS) wrote in news:e28114$acg$3
@usenet01.srv.cis.pitt.edu:

I once painted black the coil of a CB antenna. Didn't work.
I found out not all blacks are the same. Some conduct electricity.

If you look on the radar antenna of any Navy ship, you'll see a sign
warning the painters DO NOT PAINT. Paint is metal based, used to be lead
until very recently. Not good trying to pour millions of watts of pulsed
radar power through it, but is VERY fun to watch for the first few minutes,
as the fiberglass cover over the radar's feedhorn bursts into flames...(c;

Color matters not. Haze Grey conducts, too.


I think PVC is also a lossy material.


PVC is actually a great insulator. I make loading coils out of it for
kilowatt ham radio antennas. The Metz Manta marine VHF antenna uses PVC
pipe and end caps for its loading transformer for the end-fed 1/2 wave
whip. The transformer matches the near open end of the 1/2 wave whip to 50
ohms. Hams have been using PVC plumbing, the white PVC, for years.
Electrical PVC, the grey stuff, conduit and fittings is conductive, I
think, so wouldn't make good insulators. Plumbing PVC will withstand
tremendous RF voltages without breaking down...(c;

.

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