[Elecraft] Small QRP antenna
Don Wilhelm
donwilh at embarqmail.com
Thu Dec 29 12:05:36 EST 2016
Dick,
With buried radials, they do not have to be 1/4 wave long, and a single
one will probably not make much difference over your ground rod.
What you want to accomplish is a "ground screen", which means many short
(about 1/8 wavelength) close to the base of the radiator and a few
extending out further (to 1/4 or 1/2 wavelength).
Ground conductivity plays a great part in buried radials, and what you
are trying to accomplish is to increase the ground conductivity in the
area at the base of the antenna.
If you were instead using elevated radials, they would have to be
resonant - think of the various "ground plane" antennas that have been
published - 1/4 wave radiator plus 2 or 4 1/4 wave radials.
Buried radials do not have to be resonant, elevated radials must be
resonant. The ground effects will alter the resonance of buried radials
while radials in the air are a part of the total antenna resonance.
73,
Don W3FPR
On 12/29/2016 11:49 AM, Richard Fjeld wrote:
> With reference to below, I have a question please. I put up a quarter
> wave inverted-L for 160 meters. My only counterpoise is the ground rods
> at the base of the tower. I wasn't expecting much, but it does so well
> I'd like to add a decent counterpoise.
>
> If I bury a quarter wave wire, would it be best to put it under the
> Ariel wire, or opposite from it?
> Thanks in advance,
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