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[antennaware] question on ground system for good ground

To: <antennaware@contesting.com>
Subject: [antennaware] question on ground system for good ground
From: Gary Breed" <gabnjb@earthlink.net (Gary Breed)
Date: Wed, 18 Jul 2001 23:45:16 -0400
Here in the U.S., the simplest way to get an estimate of regional
ground conductivity is from the records of a nearby directional
(multi-tower) AM (medium wave) radio station.  Their operating
parameters are based on field strength measurements that are
correlated with established ground conductivity curves.  I don't know
if there are equivalent field strength measurements routinely made by
European MW stations.

An alternate experimental approximation would be to make a
dipole and measure its impedance at a low height (3 to 5M), then
raise it to 15-20M and measure it again.  I was able to determine
that the ground under my antennas is lower conductivity than 
expected from broadcast data simply by measuring the change in
resonant frequency (R +j0) at two heights.  Select various values
for conductivity in your modeling program until the model matches
the measured data.  I use EZNEC with the NEC-2 engine.

73, Gary
K9AY

  
> 
> From: "Henk Remijn" <hremijn@zeelandnet.nl>
> To: "Antennaware" <antennaware@contesting.com>
> Subject: question on ground system for good ground
To: <antennaware@contesting.com>
> Date: Wed, 18 Jul 2001 22:20:52 +0200
> 
> Hi,
> 
> I want to model some antennes but I am stuck with what ground type to
> choose.
> The place the antennes are is on a place which was before 1850 salt
> water.
> since then there is land.
> 
> What I like to know, how can I measure or calculate the ground
> resistance of
> a location.
> 
> Is there somebody around who can help me on this or who can give me some
> good links to info.
> 
> 73, Henk PA5KT
> 
> 
> 
> 
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