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Re: Making contact with AO27



<< I have been trying in vain to talk to AO27. >>

I have had a similar experience.  It is difficult to work AO27 with a hand
held and whip, but it can be done.  I'm not sure why it works when it does but
I'm thinking it has something to do with the orbit and Doppler.  Sounds
strange, but I'd like to know if anyone agrees.  

I have more success when I hear western stations from my QTH in Georgia than
when I hear eastern stations.  It seems that a good orbit can produce less
competition.  Weekdays are the only possibility.  Forget weekends.

As for Doppler, I'm thinking that the uplink works better at certain points in
the pass.  I know the satellite's band pass is fairly broad but I'm guessing
the Doppler effect puts the signal into a better part of the pass band along
the way.  I use 145.85 all the way through the pass.  I understand there is no
reason to adjust for Doppler on the uplink.  

I have a sense that the satellite locks on to my signal at a certain point for
a period of time even though someone else may appear stronger.  I would be
interested in knowing if that is possible.

Another problem with the hand held is that you almost lose the satellite
between tuning increments.  I get a good signal on 436.805 and 436.800 and
436.795, but it almost disappears between those points.  That costs valuable
time during a relatively short pass.

I would be interested in techniques others have found that prove successful.

Jimmy Walker
WA4ILO



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