[amsat-bb] RUDAK DSP weak signal test

[Jim White <jim@xxxxxxxxxxxxxxxxxxxxx>]

At the end of the RUDAK window today we left one of the DSP modulators on 
generating a signal 33 dB below the 9k6 FSK signal at 11.1 MHz in the IF 
passband.  At the WD0E station I can detect that carrier consistently at 
the beginning of the RUDAK window or a range of about 52k km. Of course as 
the range drops it's much easier to hear.  See 
http://www.coloradosatellite.com/Papers/RUDAKOps/SDish.htm
for the receive equipment here.
This is a pretty weak signal and if you can detect it you are hearing 
pretty well.  Of course it's in the digital passband only during the RUDAK 
window.

We will try to leave it on while we continue testing the other DSP 
functions and software, all of which are aimed to creating links to RUDAK 
that can be used with modest equipment.  Unfortunately we can't grantee it 
will be there all the time but will at least try to announce when it wasn't 
on after the fact.

Other work today involved the convolutional coding and scrambler settings 
on the 153k6 modulator on RUDAK-A.  All tests performed indicated 
everything is working ok but we ran out of time to finish everything scheduled.

Jim
wd0e@amsat.org
jim@coloradosatellite.com

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