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Re: AO-10 observations

This behavior you described started this past weekend.  During the entire month of December and into the new year the bird has been excellent, with great openings and strong signals from N.A. west to JA, ZL, VK, and V73, and following with perigee openings to Europe, Azores, and Russia (Africa not heard at this location in a while).  My setup is quite modest compared to yours, with antennas only 800 mm long and 20 W on UHF (FT-100 in split mode), but contacts were still plentiful.

Then last weekend I noticed the QSB was so bad I could not detect the beacon at times, even at near-perigee (under 15,000 km).  You would get about 1 minute of QSO time, then a quick shift in frequency (down about 1.5 kHz), then absolute silence for about 3 minutes.  This cycle seemed consistant Saturday through Monday.  K6YK suggested to me it was "tumbling" at a bad angle for the solar panels, which sounds reasonable since the frequency shift is exactly what you hear a few seconds before it goes into eclipse.  Let's hope it starts tumbling back the way it was last month.
Jerry, K5OE

In a message dated Thu, 18 Jan 2001  2:08:00 PM Eastern Standard Time, "Miles Mann" <Miles.Mann@ind.alcatel.com> writes:

<< It seems that Ao-10 was having battery problems yesterday Jan 17, at
10:00 utc.

Ao-10 was on is low swing from south of the equator to the mid
Altitude descending from 40,000 km down to 20,000 km during my
attempts to make contacts.
I was hoping that since A0-10 was on its close approach that signals
would be strong,
however, signals were much lower than expected.
The beacon would peak at S3 near 145.809,(12dbd antenna and 18 db
preamp on) and 
then turn into a very faint gurgle at noise level.

For my first couple of attempts there was no one on the bird.  I would
scan the
whole down link, no signals no birdies detected.

When the beacon was gone, i could not hear my down link.
When the beacon hit S1 or higher, i could align my down link easily
and hear my signal clearly.
After I made a few CQ calls, my down link would shift frequency a few
requiring me to re-tune.  (i think this is called the FM-ing problem
when batteries are dead).
After a few more CQ's, the beacon would go away and i would of course
loose my down link.

Eventually i did make a contact in the mid west (sorry i left the log
at home)
and we both saw the same problem.  It seemed the bird was only good
for about
1 minute of QSO before the batteries died.  It then took 1-3 minutes
to recharge
for another 1 minute QSO.
In keeping with good power management, i tired to keep my tx power low
25-50 watts
and well below the beacons peak of S3.

I was wondering if anyone else has see this problem.
I hope that it is only a temporary problem caused by poor illumination
angles to the solar panels (ao-10 was in full sun light at the time
and had
been for several hours).

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