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Old September 29th 07, 01:05 PM posted to rec.radio.amateur.antenna
John Ferrell John Ferrell is offline
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First recorded activity by RadioBanter: Jul 2006
Posts: 199
Default "Quarter wave ground mounted radials are a waste of wire."

On Fri, 28 Sep 2007 20:21:23 -0700, K7ITM wrote:

On Sep 27, 7:45 am, John Ferrell wrote:
On Sun, 23 Sep 2007 12:46:30 -0400, "Rick (W-A-one-R-K-T)"

wrote:

I just read the following on one of the mailing lists I subscribe to:


"Quarter wave ground mounted radials are a waste of wire and a hold over
from the olden days. Check the antenna handbook, the new philosophy is
more and shorter. The thing is that the bulk of the energy from the
vertical antenna is near the base of the antenna and this is what you are
trying to capture. A quarter wave radial sounds logical but the planet
will detune it so a quarter wave means nothing to the current."


That seems a very practical ap note. But since you issued the
challenge, I'll say I disagree with the wording of an early sentence,
where it says that ground return currents are "greatly attenuated" if
they come through lossy earth. Clearly, the current is not
attenuated; the current is what it is. However, the current through
lossy ground causes power dissipation (and loss of radiated power) in
the ground.

I think the meaning is clear, but the wording would not pass muster
with a good technical editor.

Cheers,
Tom

Good catch. It could have been more precisely stated.
In defense of the the point, Dictionary.com offers this definition of
"attenuated"- to weaken or reduce in force, intensity, effect,
quantity, or value.

OTH, lossy earth is a limiting factor to the current component of the
equation.

I think it unlikely to be misinterpretd so I would be inclined to
leave it alone. Of course, I am not a Technical Editor.

John Ferrell W8CCW
"Life is easier if you learn to
plow around the stumps"