Phil wrote:

Some of the best reasons are empirical. Numerous studies have shown
that the clutter return from the sea surface is considerably higher in
horizontal polarization. I am on vacation, so I don't have my Skolnik
handy to say exactly how much. Anyway, this favors a vertical
polarization.

Similarly, practical considerations make vertical polarization the best
for mobile applications. The 1/4 whip is the simplest antenna structure
on a mobile platform. While base stations could as easily use
horizontal or vertical, any mobile horizontal antenna will require extra
structure to implement.

In both of these applications there is nothing be gained by going to any
other polarization than vertical for these uses. In cases where
horizontal polarization has an advantage, there is no reason to go
partly vertical. So that is why the world end up either being vertical
or horizontal for the most part. Where it doesn't, polarization usually
doesn't matter or is less of a concern than other reasons (see inverted
vees and sloping dipoles).

Erich
KA6AMD


Interesting that you think that vertical is the best polarization for
mobile operation. I have done a lot of testing on 2 meters with equal
gain end to end that would indicate that you are quite mistaken.
Horizontal polarization from a fixed station to a mobile, or a mobile
station to a mobile is much more effective if horizontally polarized.
The reasons for this are well documented, so I won't go into that. The
most obvious notable difference is that "picket fence" fading is much
worse when vertically polarized.

The major reason vertical polarization is used (for FM) is that it is
easy. SSB/CW on VHF/UHF is still horizontal when mobile.

tom
K0TAR