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PJ8 Sint Maarten



Hi Lee

>>My emailer shows all of this text with lines through it.  I've noticed that 
with many of Frank's postings.  Not sure what's going on there.<<

I've had this complaint before, but have not been able to track down the 
problem.  I assume the old ASCII-text-based e-mail program (TapCis for 
CompuServe) causes it, but I don't know for sure.  I like to use TapCis 
whenever I can because it produces nice clear DOS text that is easy on the 
eyes.

>>As for the Arrow being cross polarized, it does not mean that an optimal 
downlink signal will automatically produce a minimum uplink signal.  This is 
because of the differences in Faraday rotation of the signals.  In the case 
of AO27, even though the antennas on the satellite have the same polarization 
at the bird, the amount of Faraday rotation for each band is different so 
they are unlikely to be aligned on the ground.  Also, the alignment will 
change as the distance between the ground station and the satellite changes.  
With a dual band yagi antenna, it is sometimes necessary to rotate the 
antenna while transmitting and compromise the downlink signal strength to be 
able to capture the bird more reliably while transmitting.    I have heard 
reports that nulls in transmitting were even more common when both sets of 
elements were of the same polarization.<<

So, Lee, how do you deal with the cross-polarization problem with your 
tripod-mounted Arrow.  Do you have the antenna mounted at a 45-degree angle?

Thanks and 73,
Frank
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