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RE: rotator



I agree, for LEOs.  But my setup was also used for AO-40, and a couple of 
contacts on AO-10 & 13.  Even with the limited precision (10 degrees 
elevation, and 6 on azimuth), I had little difficulty finding and tracking 
the birds.

Also for anyone else thinking of using a rotor on its side, remember that 
the bearings aren't designed to run that way.  Be gentle with the weight, 
and put something over the top to keep the rain out, because they aren't 
water tight when gravity appears to be going sideways.

Greg  KO6TH


----Original Message Follows----
From: "Robert Bruninga" <bruninga@usna.edu>
To: <ko6th_greg@hotmail.com>
CC: <amsat-bb@amsat.org>, <71611.76@compuserve.com>
Subject: RE: [amsat-bb] rotator
Date: Thu, 09 Dec 2004 21:08:06 -0500

> but I am using an Alliance on its side for elevation.

At the risk of repeating myself, (for any newcomers),
remember that you do not need an elevation rotator
for any LEO satellite, and there are currently no AMSATs
that are not LEO.

All LEO's are below 20 deg 67% of the time
All LEO's are below 40 deg 90% of the time but 4 dB closer when above
All LEO's are below 60 deg 98% of the time but 8 dB closer when above

Thus a small 10dBi gain antenna pointed up about 10 deg will give
you almost a CONSTANT gain from THe horizon to OVERHEAD.
And all existing LEO's can be heard easily with that 10 dB.  THus
no need for elevation at all.  It only adds complexity, frustration
and more to go wrong.

de WB4APR, Bob
----
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