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[aprssig] Helix Groundplane?

Robert Bruninga bruninga at usna.edu
Tue Dec 11 23:49:37 UTC 2007


> Helix antennas being circulary polorized have 
> rejection to the opposite rotation generaly 
> caused by reflections provided that both...

Wow, interesting.  I just realized then, that the "reflector
screen" at the back of a Helix is not adding any gain then.
Because it is true, that any reflected energy will be the
opposite circularity! Thus it cannot add in phase to the direct
wave.

I guess all the ground plane is doing is providing a
counterpoise for the feed system.  Oh, and possibly a degree of
attenuation to ground noise...  Both well worth the metal, I
guess.  Comments?

Bob, WB4APR





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