On Fri, 19 Dec 2003 23:09:28 GMT, Dave Shrader
wrote:
I would like to advise that an AM Broadcast station and an Amateur
station have at least one significant difference.
The AM Station is most likely running a vacuum tube amplifier at high
voltages with high voltage capacitors in the output stage. Also, they do
not have a solid state receiver connected to the same transmission line.
Therefore, they have a high tolerance to peak voltages.
My tower gets hit on average about 3 times a year. In the last 19
years I've only lost the front end out of one receiver and had a piece
of heliax blown out about 30 feet from the top of the tower.
I rarely if ever, disconnect any equipment except the computers and
with those I worry about the phone lines more than the radio station.
In the same period I've lost three computers.
Most Amateur stations, excluding members of the Kilowatt Alley Society,
have solid state finals and very sensitive solid state receiver circuits
that do not have KV level tolerance to transient voltages.
I have two KW amps hooked up to two different systems with 4 solid
state transceivers connected to the antennas. The HF rigs are
connected to the antennas through the relays in the KW amps. So the
receivers are always on the antennas except when transmitting.
Other than the amps everything here is solid state.
One of the antenna systems is near the bottom of
http://www.rogerhalstead.com/ham_files/tower.htm
here's a bit about the ground system:
http://www.rogerhalstead.com/ham_files/ground.htm
Conclusion, your argument is not totally valid!
Works for me, or has so far.
Roger Halstead (K8RI & ARRL life member)
(N833R, S# CD-2 Worlds oldest Debonair?)
www.rogerhalstead.com
Return address modified due to dumb virus checkers
Deacon Dave, W1MCE
Uncle Peter wrote:
"Andy Cowley" wrote in message
...
strike. A spark gap that can conduct a lightening strike would
be the size of a small truck.
The only way to make sure you have a working station after a
lightening strike on your aerials is to take out good insurance.
vy 73
Andy, M1EBV
Nonsense. Every insulated AM broadcast station antenna has an arc
gap at the base. How many stations get struck by lightning each year
and keep on operating?
Pete