" ... and the polarization of the Yagi makes no difference in quality of TX/RX signal."
I know I haven't been working the satellites nearly as long as Clint and many others - and with all due respect, my friend - I have to disagree with the above statement. I routinely work passes during which I swing my Arrow through, and sometimes beyond, 90 degrees to maintain signal quality. There also have been times when a quick twist of the wrist has made the difference between making a contact and getting a new grid square ... and not.
I don't-at-all disagree with the concept that working AO-27, AO-51 and SO-50 isn't terribly difficult with a handheld station. Frankly, that has really (and pleasantly) surprised me. However, I do believe that adjusting polarity when hand-holding the Arrow provides improved performance during many passes.
73 to all,
Tim
-------------- Original message from Clint Bradford clintbrad4d@earthlink.net: --------------
...20-dB, assuming the signal is pure circular
polarization...linear, then -3 dB...difference between RHCP and LHCP is 20 dB...difference between Horizontal and Vertical Linear is 20 dB...difference between (RHCP or LHCP) and (Horizontal or Vertical) is 3 dB...the VHF/UHF Manual handbook says 20 -30dB...in the real world, expect around 20~25dB loss from being completely cross- polarized...Between linear and circular, expect about 3dB loss...
Ahh, thank goodness for the engineers...
Just know that to get started working the FM satellites, you do not need to spend much to make successful contacts...Working AO-51 from Southern California (which some claim is not a "real world") at a Watt or so with an HT and Arrow Antenna is a breeze, and the polarization of the Yagi makes no difference in quality of TX/RX signal.
And as you refine your satellite comms requirements, you can spend more money!
Clint Bradford, K6LCS 909-241-7666 _______________________________________________ Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb