[Antennas] Tower As An Antenna

[Joe]

The wires or coax running up the tower do become part of the tower
antenna.  You can't prevent that.  You need to isolate it at the base
where the tower is isolated from ground.  If it is grounded (shunt
fed), I don't know.  I guess you don't need the same HV RF isolation,
but probably want to block RF currents from running off on the
cable(s) to/from the tower.

Exactly,

Joe WB9SBD


The Original Rolling Ball Clock
Idle Tyme
Idle-Tyme.com
http://www.idle-tyme.com

On 2/10/2012 4:07 PM, Andy wrote:
>> Like coaxes feeding tribanders,  rotor wires, etc. How to keep them from
>> being a part of the tower antenna?
> For coax, I think you want a choke coil, with enough inductance at the
> frequency at which you are using the tower as an antenna.
>
> For rotor wires, probably the same thing.
>
> AM broadcast stations use something called an Austin (or Austin Ring)
> transformer to isolate their tower lighting.  The transformer passes
> 60 Hz but blocks RF and isolates very high voltages.
>
> The wires or coax running up the tower do become part of the tower
> antenna.  You can't prevent that.  You need to isolate it at the base
> where the tower is isolated from ground.  If it is grounded (shunt
> fed), I don't know.  I guess you don't need the same HV RF isolation,
> but probably want to block RF currents from running off on the
> cable(s) to/from the tower.
>
> Andy
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