[amsat-bb] Re: Turn off AGC when receiving BPSK-1000
domenico.i8cvs at tin.it
Fri Aug 19 06:34:48 PDT 2011
Dave, Phil and Bob,
For additional information read
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°
----- Original Message -----
From: "Dave Guimont" <dguimon1 at san.rr.com>
To: "Phil Karn" <karn at philkarn.net>; "Bob Bruninga" <bruninga at usna.edu>
Cc: <amsat-bb at amsat.org>
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
> 73, Dave, WB6LLO
> dguimon1 at san.rr.com
> Disagree: I learn....
> Pulling for P3E...
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