[TowerTalk] Another Sort of Anomalous ground condition

Tom Rauch w8ji at contesting.com
Mon Nov 7 19:19:15 EST 2005

> 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.


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

More information about the TowerTalk mailing list