Thanks for the comments Mark. I do appreciate your taking time to give me
some advice. I only have a limited space around my home so can't put up a
one wave per side. I am currently using a sloping dipole and doing fairly
well but need to improve the reception to cover Texas, Arkansas, Oklahoma
and Louisiana for Navy MARS region nets. I saw an article somewhere that
indicated a V Beam 3/4 wave on a side would provide 3 dB gain over a dipole
in one direction. I will have to research it some more but it is really
difficult to find information on V Beams on the net. If you do discover any
more info I sure would appreciate you sharing it with me. Thanks again,
73, Bob
"Mark Keith" wrote in message ...
Bob Wood wrote:
V Beam antenna question
I want to put up a 40M V Beam antenna to enhance communication in one
direction only. From the limited design information that I have found,
I am
thinking of 3/4 wavelength on each side with a horizontal separation
angle
of either 72 degrees or 120 degrees. I have seen both separation angles
listed as optimum for maximum gain. I was wondering if anyone knew for
sure
which angle would produce the best result. Also, and actually most
important, I need to have some idea of what the feed point impedance
might
be. I can feed it with ladder line or good coax and a balun but I am
not
sure what balun to use or would it be better to use ladder line? I sure
would appreciate any guidance on this antenna project.
Bob
W5QCP
A true V beam is a minimum of one wave per side. And that minimum is not
much of a V beam...I'd have to double check, but with 3/4 wave per leg,
IE: about the same as an extended double zepp, I think you would have
the most gain with it straight like a normal EDZ. appx 5.1 dbi
bidirectional. I bet your gain will drop off if you try to set it up
like a V beam. As far as the feed impedance, it will vary per band. Not
really a major issue. Just treat it like any other balanced antenna fed
with ladder line. If if tunes, fine. If not, you might need to vary tyhe
feedline length a bit. You could feed with coax for a 3/4 wave per leg
antenna, "also 1/4 wave per leg on whatever band.." , but it would be
better to use a ladder line for all band use. MK
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