> I am getting ready to put up beverages for cqww. I have enough room top
> put them up at least 540 ft(approximately 4 wavelengths on 40 mtrs). I
> have enough room to make one of them around 850-900 ft. I have heard that
> it is best to make them exact multiples of the highest frequency for which
> they are to be used. Nr 14 guage wire will be used, and they will be
> around 10 feet high. I will be using them on 160, 80 and 40. This is the
> first time I have constructed a beverage, and am really a rookie with
> these antennas. Any thoughts that the oldtimers could give me about the
> lengths etc would be a big help. Bill K4XS
I have reservations about using multiple-wavelength-long
Beverages.
First, the loss in the antenna limits the directivity increase as it is
made longer. That won't hurt much, but what it does mean is you
often won't get the sharp pattern you expect. The extra wire may
not be worth it.
Second, I've found that with distances as small as two wavelengths
or more...the signal is almost never in a stable phase relationship
at both places at the same time. This means the signal will have
random phase and amplitude differences and not "add" properly in
the wire.
I used to think the first reason was why I was always disappointed
when comparing long Beverages (over 2wl) to shorter Beverages,
but after playing with antennas spread over a large area I find that a
signal often has different fading times on an identical antenna just
1000 feet away on 160 meters! Now I believe that effect is a big
player in why I never saw a significant improvement with long
Beverages compared to 1 wl antennas.
As to operation on 40 meters, they should work OK but the height
is a problem! They'll work better closer to the ground on 80 and 40,
ten feet is a bit too high.
73, Tom W8JI
w8ji@contesting.com
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