Bill,
I think you are referring to the terminated Vee beam that they show as a
sloper.
It can give good performance on the higher bands as a DX antenna. You get
gain out of a horizontal vee, (or a sloping vee) when the leg length exceeds
a couple of wavelengths. Otherwise it will act as any non resonant doublet
with legs folded upon itself. There should be some directivity in the
direction of the axis between the legs.
With a single support, you could theoretically steer your directivity by
rotating the legs and staking them out in a differing direction, to favor
certain DX for example.
Our club has run horizontal versions of this antenna for Field Day for about
3 years, and at low heights. We found if you put the apex up too high, (40
feet) it was ONLY a DX antenna, and did not work the areas in between the
coasts well. Eventually we switched to horizontal loops for more omni
coverage. Vee beams are fun, bi-directional along the axis, (if not
terminated) and have a lot of gain if you can put up so much wire. We had
10 waves at 10m, which is 320 feet of wire. The quarter wave section at the
end of a vee beam leg can be disconnected to unterminate the vee. TT uses
a dissipative resistor load as I recall, and you could unterminate that as
well, but your back wave would mostly fire up into space, unless you had a
nice ionized cloud to reflect it back.
-Stuart
K5KVH
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