Re: [amsat-bb] Helix antennas & EME

[John Magliacane <magliaco@xxxxxxxxxxxxxx>]

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 -=-=-=-=-=-=-=-=-=-=-=-=-
Internet  : kd2bd@amsat.org          |  Voice : +1.732.224.2948
Satellite : AO-16, KO-25             |  Morse : -.-  -..  ..---  -...  -..
Packet    : KD2BD @ N2SMV.NJ.USA.NA  |  WWW   : http://www.njin.net/~magliaco/
Video     : 426.250 MHz/439.250 MHz  |  FAX   : +1.732.224.2060
-=-=-=-=-=-=-=-=-=-=-=- Linux Doesn't Cost.  It Pays. -=-=-=-=-=-=-=-=-=-=-=-

----
Via the amsat-bb mailing list at AMSAT.ORG courtesy of AMSAT-NA.
To unsubscribe, send "unsubscribe amsat-bb" to Majordomo@amsat.org