>From: Nick Hall-Patch <nhp@ieee.org>
> >Consider the case where several wires are run along the
> >ground under the beverage to "normalize" irregularities in
> >the ground - the primary effect is a decrease in the
> >difference in velocity factors resulting in less signal per
> >foot.. that's why it takes typically 4 wavelengths in that
> >situation to be have like a "regular" 2 wavelength beverage,
> >specifically to have the same pattern..
> >
>
>I've used medium wave Beverages (partially) over Pacific Ocean salt water,
>and heard plenty of DX. There was no scientific comparison made by putting
>up a nearby Beverage over poor ground, as this was a very temporary wire (a
>few hours).
>
>But, do not arriving skywaves have a horizontal component anyway, which is
>what is needed to make Beverage antennas work? Weren't Beverage's
>original experiments done with rather long vertically polarized waves which
>only acquired a horizontal component if the ground underneath the wire was
>of poor conductivity. At higher frequencies, is the poor ground nearly so
>important?
>
>Could experts on the list please clarify?
There has been a lot of discussion and little agreement on this specific
topic by numerous "experts". W1WCR advocates a ground wire under the HF
Beverage, based exactly on what you said. Others say the whole idea is
totally wrong. We need some actual test results comparing a real antenna
with and without "good" ground underneath. The problem is, with typical
varying propagation and noise situations, it is about impossible to install
and remove a ground wire under a Beverage several hundred feet long quickly
enough to get any meaningful test results.
I would suggest someone with enough real estate and time on his/her hands to
put up two similar Beverages several hundred feet apart, and maybe a
vertical reference antenna, well removed from the Beverages. Make
comparisons among all 3 antennas with no ground wire. Carefully document
the results. Now add ground wire under one of the beverages, and once
again compare all antennas. The "control" antenna would be the one that
never had a ground, plus the vertical. Now take measurements with the test
antenna, comparing it with the other antennas, under a variety of condx.
Repeat, after ground wire is added under the test antenna. Maybe some kind
of definitive conclusion could be drawn.
Just about all the discussion I have heard on t his subject has been
speculative, including W1WCR's proposition in his Beverage book. What
experimental results I have seen have been highly unscientific and
subjective, with no control test data.
Has anyone ever tried a similar experiment and published the data?
Don K4KYV
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