On Sun, 12 Sep 2010 20:08:54 -0500, ve4xt@mts.net wrote:
>Anyone have any information on how vertical dipoles perform when elevated?
I built one for 40M and hung the top of it at about 100 ft in a redwood. I
also modeled it in NEC. The model and on-the-air performance were in general
agreement -- because of the way it interacts with the earth in the far field,
it's a lousy antenna, and something one would use only if it was the only
option. The same support that holds a vertical dipole would be far better
utilized supporting the feedpoint of an inverted Vee. That is, you'll be
about 10dB louder in almost any direction and at almost any vertical angle on
the inverted Vee. :)
To see photos, construction details, and graphs from the NEC model, look at
the very the end of my Power Point on coax chokes (pages 69-73).
http://audiosystemsgroup.com/CoaxChokesPPT.pdf
73, Jim K9YC
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