[Amps] crossmodulation in PA ? Thanks for all good??advice

[Gary Schafer]

The myth has not been dispelled.  :>)
The purpose of a bonding wire around the rotator is to reduce the voltage
that the rotator sees when lightning hits the mast and conducts current thru
the rotator. How many rotator pots have you heard of being fried? I have
several here.
The thrust bearing or sleeve where the mast goes into the tower can have
very high resistance so the rotator can see full current from lightning. The
rotator bearings are less than perfect grounds also and a voltage difference
can occur between the rotator bell and bottom zapping the innards and also
letting the voltage onto the control lines.
Joints that are going to conduct lightning currents successfully require
very low resistance connections.

73
Gary  K4FMX

> -----Original Message-----
> From: amps-bounces at contesting.com [mailto:amps-bounces at contesting.com] On
> Behalf Of Robert Chudek
> Sent: Friday, September 07, 2007 10:47 AM
> To: amps at contesting.com
> Subject: Re: [Amps] crossmodulation in PA ? Thanks for all good??advice
> 
> This misplaced bonding effort applies to bonding around a rotator as well.
> We already dispelled the myth (on the TowerTalk reflector) of rotator
> bearnings being welded by a lightning strike. Common sense tells us the
> rotator is protected by a Faraday shield anyway (the tower).
> 
> 73 de Bob - KØRC in MN