A similar set of examples of apparent one way HF communication:
Michigan to Bangladesh in the rainy season. [much more QRN at one end than
the other]
Michigan to Antarctica in the (N.A.) Summer [heavy QRN on one end, none on
the other end]

.... and then there are the paths that have to go through the magnetic pole
....

These examples assume reasonable equipment in a rural setting.

73 Mac N8TT

--
J. Mc Laughlin; Michigan U.S.A.
Home:
"Roy Lewallen" wrote in message
...


The idea that if you can hear a station he can hear you is totally
wrong, especially at HF. At HF, you can have a terribly inefficient
antenna and hear people just fine. This is because the dominant noise is
coming from outside the receiver and therefore both signal and noise are
attenuated by the same amount by the loss. I can easily hear 20 meter DX
on my little Sony SW radio with a 2 foot rod antenna. But there's no
hope they'd hear me if I were transmitting with that antenna, even if
I'm running an equal or much greater amount of power than they are.

At VHF and above, where receiver noise dominates, a station you hear can
hear you if you're running about the same amount of power and if your
receivers have about the same noise figure. But this isn't at all true
at HF and below.

Roy Lewallen, W7EL