Topband: Noise and reception

[Mike]

> Most DX signals, if not nearly all signals at a modest or greater
> distances, are vertically polarized when near earth. That is why our
> "noise" is substantially vertically polarized, and signals are no
> different. This is why Flags, Pennants, Beverages, and arrays of
> small verticals work so well, and have evolved into the antennas of
> choice.
>
Tom,

Are you suggesting that signals arriving from the ionosphere at
moderate to low elevation angles are predominatly vertically
polarized? I was always led to believe that they were basically
randomly polarized and that the polarization was time varying
to some degree. I can understand how the earth modifies the
pattern of an antenna (the reflected versus direct waves add or
subtract depending on their relative phase), but please explain
to me how the earth modifies the polarization of an incident
wave independent of the antenna? This kind of goes against
the grain of my understanding of plane wave reflection
mechanics.

Thanks,

Mike, W4EF......................