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Old May 19th 06, 04:53 PM posted to rec.radio.amateur.antenna
Richard Harrison
 
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Default Running wire close to HF transmit antenna

Ben Jackson wrote:
"Let`s say I have a free-standing vertical HF antenna about 10 wa, and
I`d like to run wires to something at the tip."

No problem.

All the stations I`ve worked in, medium wave and shortwave, had lighted
towers. Some also used the towers to support other antennas and devices.
Medium wave towers have sampling loops bolted to them for remote current
and phase indications.

It`s dead simple. Conduit and coax are used to protect wires to devices
and other antennas. Conduit and coax are firmly connected, top and
bottom, at least, to the tower to shift most of the lightning to the
lower-inductance tower.

At the bottom across the base insulator, coax is coiled to create a
reactance at least 10x the feedpoint impedance of the tower. Similarly,
each of the other wires running up the tower for illumination or other
purposes is broken at the base for a tower-lighting choke (or Austin
transformer) to isolate the RF and lightning. It works like a charm.

Best regards, Richard Harrison, KB5WZI