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Re: UO-22 azimuth-only system



Hi Bob

>  Two important points.  Below 10 deg where 30% of all passes are, the
>  satellties are also 10 dB further away.  You dont want to give up
> ANY gain on the horizon.  So point your beam at 10 degrees which
> gives full gain from 0 to about 20 or more where you need it most.

Except that in the case of my QTH at the time, in most directions my 
horizon was about 10 degrees anyway so that was never an issue.

>  As the satellite gets higher, it is closer and so any drop in gain
> above 40 deg is more than made up for by the satellite being 6 dB
> closer and only being there 8% of all in-view times.

Thats what I noticed. Even with overhead passes the signals didn't 
really disappear, however the problem was that I would have to then put 
the rotator through 180 degrees and that would lose me more signal 
during its traverse.

>  And I am not "pushing APRStk" here.  I wish OTHER amateur satellite
>  tracking programs would provide the simple two-bit LPT1 port (right,
> left) control for such simple ($20) rotator systems.  See the web
> page above...
>
>  We dont need full AZ/EL OSCAR class arrays and $800 rotator
> controller systems for *ANY* LEO satellite.  And all of our satelltes
> are LEO's except for OSCAR 10 and 40.  I wish more authors and AMSAT
> programmers would recognize this and support the simple LEFT-RIGHT
> cheap-TV rotator interface...  I think it would bring in more people
> to working the LEO birds.

As a software author myself (Mtrack, one of the Linux satellite 
tracking programs) I can't say I have noticed that specification at 
all. My current project is FSK441 and JT44 for Linux, maybe I'll come 
back to Mtrack after that.

>  de WB4APR

Jonathan  HB9DRD/G4KLX
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