Hello-
I am very interested in this topic. I have a "third wavelength" inverted
'L',(total length of 175 feet with 65 feet in the vertical section) whose
feedpoint is 7 feet above ground with 4 symetrical elevated radials 1/4
wavelength long. Directly underneath this feedpoint, I have a ground pipe
(copper water tubing) and a separate radial system, lying just below the
surface. This "ground reflector" consists of 20 1/4 wavelength radials and 2
1/2 wavelength radials. The longer radials run approximately under the
horizontal radiator of the 'L'. The ground condition here is rocky gravel
and quite dry. I plan on adding 4 more elevated radials. All of the
elevated radials are #18AWG insulated wire. The ground radials are attached
to the ground rod using copper "pipe hangers" that are clamped to the ground
pipe and holes in the strap are used to attach the radials. (they are silver
soldered to the strap)
My experience in putting up this antenna with just the 4 elevated radials
indicates that the whole system improves significantly with the addition of
the ground radials. Signals are typically 2 to 3 S units better with the
"ground mirror".
I am sure with more ground radials, the results would be even better.
Scott
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