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Re: UO-22 azimuth-only system




>
>Steering antennas during LEO passes can be very exciting.
>
>People have done research on this - trying to match the
>gain of an antenna with the position and range of the
>satellite. Get it right and you don't need to steer the
>antenna at all, because the main lobe of the antenna's
>pattern coincides with the most likely location of
>the satellite.

Where were you, Laura, when we were looking for volunteers for the antenna
switching project?

A friend in Australia wrote a program that attaches to IT, and will switch 
a relay
to select an antenna that is designed for various elevations.

I use it here in conjuction with a quadrifilar mounted vertically (good 
sigs above
30° El), and a j-pole (good sigs to 30° EL).  It works very well, simple, 
and no
rotors required.  Very inexpensive low loss receive relays are available 
for the low
orbits...Higher freqs on AO40 will probably cost tho...

Pick ANY antenna patterns, and combine them in any way to get the desired 
gain (direction)
and one can throw the rotors away.

AO40 came along, and we all lost interest.  The goal was to take advantage 
of the 10db
gain we were told about for AO40.  If and when AO40 is stabilized, and when 
"Joe Ham"
gets to use "prime time" I intend to resume those experiments on 40...a 
cadre of those
interested at one time hopefully will also contribute....

Some of the prep work is at:

http://home.san.rr.com/doguimont/uploads





            73, Dave wb6llo@amsat.org
                    Disagree: I learn....

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