Ralph Mowery wrote:
. . .
The thing of hearing a station and he can hear you is also bogus in some
cases. I was trying to work a mobile on 80 meters that was parked running
100 watts. I could hear him just fine. About 1/4 scale on my S-meter. He
could not hear me for some local (to him) qrm and qrn. By turning on my amp
we could work each other.
. . .

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