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Old May 5th 04, 11:38 PM
Gene Fuller
 
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Richard,

Are you sure you meant the statements quoted below?

Horizontal polarization bounces just fine from "horizontally conducting
surfaces". Indeed, when a mixed polarization wave hits a conducting
surface the horizontal polarization in the reflected wave is enhanced,
not "short-circuited". This is the same phenomenon that is the related
to Brewster's angle.

Perhaps you really meant to say that a special guided wave mode, namely
the ground wave, does not support horizontal polarization.

73,
Gene
W4SZ



Richard Clark wrote:

[Lots of more or less correct stuff snipped]


Well, this is where you are in over your head (water metaphors are
abundant in this topic). This, again, requires presumptions insofar
as the original observation was driven by the AM example. However, at
this point we will depart from the low frequency mandate to examine
another mandate: polarization and your presumption of conductivity.

A horizontally polarized antenna seeing a horizontally conducting
surface is a scenario that describes a self-short-circuit.
Horizontally polarized waves meeting the earth (a conductive one)
immediately snuff themselves (how long would your car battery last
with a screwdriver held across its poles?).

On the other hand, vertical antennas do not suffer this fate - and for
the same reason: it is a current wave (or at least the magnetic
component inducing such a current, in a conductive earth) that spans
earth making a perfectly reasonable relationship to continued
propagation.


[More snip]