At 03:56 AM 9/20/2008, Anthony Monteiro wrote:
At 07:29 PM 9/19/2008, Clint Bradford wrote:
...I have to disagree with Clint...
I just must be the luckiest S.O.B.(*) working AO-51, then...During demonstrations in front of folks, someone in the assemblage almost always asks about polarization. I twist the Arrow, and we all "hear" no difference in its strong, clean signal.
Clint, K6LCS 909-241-7666
Dear Clint and friends,
There is no luck involved. The UHF downlinks on AO-51 are circularly polarized. You can twist your Arrow all you want and you will not hear any difference, nor could you measure any because there isn't any difference!
The cross-polarization loss from a circular TX antenna to a linear RX antenna is a constant 3 dB regardless of the actual linear polarization angle.
If you want to demonstrate polarization mismatch loss, use AO-27 (which is linear) with an Arrow.
73, Tony AA2TX
Well, theoretically the signal from AO-51 might be somewhat elliptical if there is a significant squint angle. Apparently this does not happen with enough change to be detectable. The human ear cannot detect audio level differences under 3-dB. Other effects probably mask any measurable variance.
73 Ed - KL7UW