re: unilateral E/W propagation

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f6irf
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re: unilateral E/W propagation

I have seen a few comments on the chat regarding the a/m topic...
Very interesting topic indeed !

For info, I have pointed out this phenomena on my blog for quite some time:
http://f6irf.blogspot.com/2008/05/is-propagation-always-bilateral.html
And more recently with a 160m path analysis
http://f6irf.blogspot.com/2008/11/160m-good-example-of-unsymetrical-path...

For the lower bands, I think the answer, is provided by the noise-map of the "propagated man-made noise level". (at NVIS angles)
For the higher bands, where "propagated man made noise" is less a dominant

factor (unless "purely local"), it might just be a question of "antenna efficiency" (a poor TX-antenna can make a very good RX antenna; for example a resistively loaded dipole, a beverage, a magn-loop, a K9AY, are excellent receiving antennas)

At this stage I am not sure that real unilateral propagation modes may exist...
but I would not put more than 1$ on this hypothesis - Faraday rotation on EME links, is a reality, and it can make the paths moreless unilateral (unless you are using circular polarization). So, who knows ?

Maybe some reports and studies are sleeping somewhere in the ITU archives (kilometers of files !)...

Pat