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Re: Helix antennas & EME

On Tue, 9 Nov 1999, Claudio Martins wrote:

> Hi!
>    Although it may be a little off topic I would like to know if someone
> has tried to use Helix antennas for Moonbounce work.
>    They are good simple antennas for satellite, and I have been trying
> with several designs and aparently one can obtain high gains with them.
> Could a stack of helix antennas be used for EME (perhaps at 432MHz and
> up), in order to help solve the polariation rotation problem? Of course, 
> the array gain would have to be higher in order to compensate for
> receiving a linear polarized signal with a circular polarized antenna, 
> right?

The only problem is that the moon reflection will have the wrong
polarization sense for the helix (unless you use separate arrays for
transmitting and receiving).  In other words, a RHCP signal will be
reflected as a LHCP signal, and vice versa.

73, de John, KD2BD

-=-=-=-=-=-=-=-=-=-=-=-=- John A. Magliacane, KD2BD -=-=-=-=-=-=-=-=-=-=-=-=-
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