----- Original Message ----- From: "Dave Guimont" dguimon1@san.rr.com To: "Bill Dzurilla" billdz.geo@yahoo.com Cc: amsat-bb@amsat.org Sent: Tuesday, February 19, 2008 12:48 PM Subject: [amsat-bb] Re: Sat antenna fixed elevation -- how many degrees is the best?
... I use home brew quadrifilars, rotate with a little TV rotor, 2M and 70 cm on the same mast. By experiment, I determined the beamwidth ~65°, so I fixed EL at 30°.
And if the satellite downlink is strong enough to be heard at all I get the entire pass....
My observations mirror yours exactly, except that I find directly overhead to be fairly hard to hear(no pre-amp) so I avoid direct-overhead passes, or wait untill it's gone past to start talking. Since I am controlling the radio and rad-shack rotor manually, doppler and azimuth are too fast going overhead for me to track anyways. I also happen to use a little less elevation, which doesn't help the overhead part one bit! I think it's a nice compromise untill I can afford a new rotor system.
73's Auke VE6PWN