Antenna wire
On Sat, 26 Aug 2006 09:39:46 GMT, Paul Hinman
wrote:
As long as gravity exists will it ever be possible to get a perfectly
horizontal dipole?
Hi Paul,
If you read my further responses to Owen, you find the discussion of
catenaries. In that regard, the answer to your question is
unquestionably YES!
You merely need to provide a catenary supporting the perfectly
horizontal dipole. Regard any suspension bridge to discover the
mechanics of construction. And, yes, the road bed is not horizontal,
but an arc built to anticipate load; the ingenious antenna builder can
reconcile this (trolley systems across the world with overhead
suspended wires solve this easily).
The question for this relative neophyte is,
what effect does the sag have on antenna performance?
Barring the suspension method, and the wire sags, it becomes a
question of how much, and more importantly, in what relation to
ground? If you have a 160M dipole with the ends up 10 meters, and a
sag of only 0.1°, then you still have a dog. If it is a 10M dipole
with a 10° sag, then you have a performer. This is a 100 fold
variation that would seem to invert expectations - if were not for the
wavelength and relation to ground.
73's
Richard Clark, KB7QHC
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