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Re: [TowerTalk] Another Sort of Anomalous ground condition

To: "ROBERT CARROLL" <w2wg@comcast.net>, <towertalk@contesting.com>
Subject: Re: [TowerTalk] Another Sort of Anomalous ground condition
From: "Tom Rauch" <w8ji@contesting.com>
Reply-to: Tom Rauch <w8ji@contesting.com>
Date: Mon, 7 Nov 2005 19:19:15 -0500
List-post: <mailto:towertalk@contesting.com>
> The story is too long to tell, but involves worries about
coupling into RX
> antenna ports when using a Beverage or other antenna.  No
sign of problem
> there, but by chance I touched the tip connector of a
cable connected to the
> antenna jack of a backup second transceiver/amp
combination and was
> surprised to hear some nice sweepstakes signals.  They
were about 5 s-units
> down from the reading on the main setup.  In investigating
I find that I can
> short the transceiver coax and the signals go away, but if
I touch the coax
> tip to even the ground post on the transceiver I can hear
signals.  And if I
> touch it to the single point ground I am using--which is
about four feet
> from the power ground--I get even better signals. Just to
make sure this was
> not a ground conductor inductance issue,  I did the
experiment while
> listening to a broadcast station.  The ground makes a nice
broadcast band
> antenna, and the signals are quite a bit stronger than
those I get by
> touching the tip of the coax myself.

Bob,

I don't think you have any sort of problem at all. Nothing
your are doing tells me your ground system is flawed in a
way that will affect receiving antennas.

I can have (and had in the past) stations without any RF
ground near the house. My station now really doesn't have
what I would consider a great RF ground. Why do I need one?

The only time we need a really good RF ground in the station
is when we are feeding an antenna that brings the feedpoint
into the house. Long wires, end-fed Hertz, random wires,
poorly designed Zepps, verticals with crummy ground systems,
and similar antennas often require the band-aid of having a
good RF ground. For properly designed two conductor feedline
antennas it makes no difference at all if the shack has an
RF ground or not.

73 Tom


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