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Re: [TowerTalk] Radials

To: "Thomas Giella KN4LF" <>,"a TowerTalk COL" <>
Subject: Re: [TowerTalk] Radials
From: "mryan001" <>
Date: Fri, 30 Mar 2007 16:07:55 -0500
List-post: <>
Tom, Your comments have been relayed on several website that discuss the
radials under inverted the " L " for 160.  Also on the Butternut site they
say that the radials should AT LEAST be as long as the antenna is high as a
rule of thumb.  Salt (sea) water being the best or near most perfect ground
although fresh water was not considered to be that great of an improvement
to soil conductivity and therefore, the radial system but better than most
dry soils.  I will say that I wished I had read what your test results have
proven when I put down the radials I did for my inverted L down here in
Palmetto. I put down about 2000ft of wire. Worse than that, the line noise
is so bad down here that I think I could talk to you easier up there in
Lakeland with two tomato soup cans and some string than on 160. One day I
would like to get some more info from you about the static arrestor you use
on your vertical. I need one of those here.  -Mike, K4CVL

-----Original Message-----
[]On Behalf Of Thomas Giella
Sent: Friday, March 30, 2007 12:49 PM
To: a TowerTalk COL
Subject: Re: [TowerTalk] Radials

I've done extensive experimentation with radials on vertical antennas on
160 meters during the past 18 years.

Back in 2001 a MF broadcast engineer friend of mine using professional
broadcast measuring equipment, took near field measurements of the electric
field in V/m RMS. The antenna was a 1/4 wave inverted L with a 64 foot
vertical section and (1/8 wave) 64 foot long radials laying on the ground

I found the following.

There was little measurable difference between 0 and 4 radials, a small
measurable difference between 4 and 8 radials, a medium measurable
difference between 8-16 radials, a large measurable difference between 16
and 32 radials, a small measurable difference between 32 and 64 and no
discernable measurable difference between 64 and 120 radials.

We then conducted another experiment using conventional (1/4 wave) 128 foot
radials and
found the data to be exactly the same as the 1/8 wave radials. To me this
the theory that the radials need not be any longer than the vertical section
is tall.

I have never had the opportunity to do the experiment with a full 1/4 wave

This statement will be controversial. Using a voltage fed electrical 1/2
wave tee antenna with a 64 foot vertical section and three 200 foot long
top hat wires, in the near field we measured only a very small difference
1 radial and 64 1/8 wave radials. We measured no difference between 1 radial
and 64 1/4 wave radials.

The ground conductivity was pretty good at the location of the experiment.
It was
a typical Florida hammock swamp that had been filled in but always had black
soil and a high water table. The conductivity was approximately .03 S/M with
a dielectric
constant of approximately 20.

I've always presumed that the results might be different over ground with
poor conductivity.

- -... ...- -,
Thomas F. Giella, KN4LF
Lakeland, FL, USA

KN4LF SWL & Amateur Radio Autobiography:
New Scientific Evidence for the Existence of God:


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