> Subject: TopBand: Rohn SSV as 160M antenna?
To: <topband@contesting.com>
> Date: Wed, 20 Aug 97 11:58:34 +0000
> I am putting up a rhon SSV 100' freestanding tower with #8 bottom
>section and #4 straight top section. There will be a 6 meter beam on
>a 34' boom and a 17' mast out the top. Has anyone else loaded s> 73
>GEO (K0FF)
Hi George,
When a structure tapers to a narrower point at the outer end, it
looks electrically shorter and the bandwidth gets narrower. Think of
it as a backwards fed discone, with opposite results.
That's because the distributed capacitance decreases right where you
need it most, at the most concentrated area of E-field. You wind up
with a long area of antenna with reduced current, and hence reduced
radiation.
I have no idea how that will affect your tower, the beam on top
will tend to offset the effect somewhat. It would be worth
looking at on a modeling program, because you might find (or might
not find) a uniform cross section wire cage will help.
73 Tom
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