Dave, Phil and Bob, For additional information read
http://www.w2du.com/r2ch22.pdf and look at Fig 22-7 page 10 of 20 Radiation Pattern of the 1 1/2 turn 1,25 wavelenght Quadrifilar Antennas. With the antenna straight up pointed to Zenith the gain is 4 dBi all around the azimuth at 30° elevation and -3 dBi overhead at 90° elevation. 73" de i8CVS Domenico ----- Original Message ----- From: "Dave Guimont" <[email protected]> To: "Phil Karn" <[email protected]>; "Bob Bruninga" <[email protected]> Cc: <[email protected]> Sent: Friday, August 19, 2011 7:31 AM Subject: [amsat-bb] Re: Turn off AGC when receiving BPSK-1000 > > > > >You don't have to use a narrow beam antenna with maximum gain on axis. > >You can always design it with a bowl-shaped pattern that increases gain > >toward the edges and lowers it in the middle. > > That's why the quadrifilars work so well. I measured the pattern some > time back, and the "beam width" is about 140 degrees.... > > Point them straight up and be satisfied with that part of a pass, or > mount them at 40 degrees, and rotate AZ with a TV rotor for the > entire pass. For 50 degree max passes point them at the center of the pass... > > > > > 73, Dave, WB6LLO > [email protected] > > Disagree: I learn.... > > Pulling for P3E... > _______________________________________________ > Sent via [email protected]. Opinions expressed are those of the author. > Not an AMSAT-NA member? Join now to support the amateur satellite program! > Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb _______________________________________________ Sent via [email protected]. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
