RadioBanter - View Single Post

July 30th 03, 04:10 PM

(WShoots1) wrote:

Note that with solid state receivers, any neon bulb protection won't help. Neon
takes I beleve about 65 volts to fire. That's too much for a solid state front
end.

That's true, but the rise time is in nanoseconds and the neon lamp
(or, more appropriately, a gas tube suppressor paired with a high
voltage capaciter, a'la Polyphaser or ICE) will prevent damage from
occurring.

A neon lamp will work for near misses. A gas tube will work better
and more reliably, because the size and shape of the contacts and the
gas mix used will be tailor made for them to fire quickly. Note that
they present a dead short when firing.

Diodes have been used but, unless configured correctly with suitable diodes,
radio noise will be created.

True. You can do it with diodes, but even with recommended ones I've
had problems, so I avoid that approach.

As was recommended -- disconnect the antenna. Only commercial stations need to
keep on a-chugging, and even then they disconnect the antenna, at a stopping
point, and then switch it to a good ground. The protection is for things that
have to remain connected, like emergency frequency receivers.

I still recommend the Polyphaser over disconnecting. The reason? The
polyphaser provides a very low resistance path to ground for the near
miss and/or direct hit you get.

If you just disconnect and leave the coax laying there, you are
opening yourself up to side-flashes. You really don't want to do
that. To REALLY disconnect and be safe, disconnect, put a shorted
connector on your radio, and fasten the coax to copper strap to
ground.

I speak from experience. Since using PolyPhaser I've never had the
slightest problem with lightning. I live in the colorado front range,
and we get lightning here you can't imagine. I also took a direct
strike, once, and other than destroying the coax leading to the
polyphaser, everything was fine.

BTW, I don't know any commercial stations that go off the air for
thunderstorms. Most have hot backups available, though.

Bill, K5BY

--
Eric F. Richards,
"This book reads like a headache on paper."
http://www.cnn.com/2001/CAREER/readi...one/index.html