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Old November 29th 08, 07:07 PM posted to rec.radio.amateur.antenna
Jerry[_5_] Jerry[_5_] is offline
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First recorded activity by RadioBanter: Jun 2008
Posts: 133
Default Quad and circular polarization


"Roy Lewallen" wrote in message
treetonline...
-.-. --.- wrote:
. . .
By the way, due to wavelenght we are playing in the HF, i doubt that can
be realized a true circular polarization antenna for HF spectrum. Maybe
something can be realized on VHF and up. . .


I agree. My experience is that:

1. It's difficult to generate circular polarization in more than two
opposite directions at HF. With something like crossed dipoles fed in
quadrature (sometimes called a turnstile), the polarization is circular
only at right angles to the plane of the dipoles. It's linear to the sides
and elliptical elsewhere.
2. Even after you generate a circularly polarized signal, ground
reflection tends to make it linear. It's difficult or impossible to avoid
ground reflection over an HF path.

Roy Lewallen, W7EL


Hi Roy

Just for conversation, I submit that an antenna with good hemispheric CP
coverage could be made with 4 dipoles.

Jerry KD6JDJ