Consider me to also not be an expert either in Beverage antenna theory, or in
wave propagation. I wonder however whether some of the idea that the Beverage
works best over poor ground dates back to the original development of the
antenna, when it was used for low frequencies that were propagated by ground
wave that had no horizontal component to the wavefront. This would not produce
much signal on a Beverage antenna that is dependent upon that horizontal
component, unless the wavefront was passing over a poor ground that would cause
it to tilt, introducing a horizontal component.
Most of us use Beverage antennas for DXing on medium frequencies, and the
signals we receive are skywave. Even if the original wavefront had no
horizontal component, by the time the ionosphere has finished with it, and
delivered it to our receiver, there may be quite a reasonable horizontal
component to it. One would expect that a Beverage antenna should therefore be
able to generate a signal, even with quite a good ground underneath.
Standing by for corrections to my perception...
73,
Nick
VE7DXR
Quoting rfoxwor1@tampabay.rr.com:
>
> ---- Greg - ZL3IX <zl3ix@inet.net.nz> wrote:
> > Hi Eric,
> >
> > I am interested in a statement in your paper, "Beverages don't work over
> > high(ly) conductive earth"
> >
>
> This may be very simplified. I am far from a Beverage expert, but it was
> explained to me once that the Bev works well over poorly conducting
> soil because the wavefront is no longer just vertically oriented, as it
> travels down the length of the antenna wire; but rather is retarded,
> causing a forward tilt in the wavefront. This forward tilt then will
> induce a RF current down the length of the wire, which sums up at the
> end (where the RX is). IOW instead of just a vertical field, there is
> both a vertical and a smaller horizontal field, and the poorer the soil,
> the greater horizontal field induces the antenna current you need.
> -Bob k2euh
>
--
Nick Hall-Patch
Victoria, BC
Canada
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UR RST IS ... ... ..9 QSB QSB - hw? BK
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