If you go with a larger beam, anything more than 3 or 4 elements, you will likely need an elevation rotor as well, but this is a configuration more suited to HEOs than LEOs.
To amplify on that, for LEO's you don't need an elevation rotator for beams of several elements probablly up to 8 or more elements because 67% of all the times the satellite is in view, it is below 20 degrees anyway. It is only above 45 degrees less than 5% of the time. It is only above 60 deg 2% of all possible time, so just mount the beam up at about 10 degrees and you will get maximum gain down on the horizon up to about 40 degrees where you need it most when the satellite is far away (95% of the time). When it is above 45 degrees it is 10 dB closer to you anyway, and you can afford to be offpointed a bit.
Bob
73, Jerry, M0GOE
----- Original Message ----- From: "Norman W Osborne VE3CJE" nwosborne@shaw.ca To: amsat-bb@amsat.org Sent: Friday, November 17, 2006 5:09 PM Subject: [amsat-bb] Comparison Quadrifiar verses TMP ll
Just wondering, how the comparison of Texas Potato Mashers
ll verses the
Quadrifilar Helix for Leo's. Both with the ability to switch RHCP and LHCP
Norman.
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