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Old August 29th 04, 09:55 PM
Roy Lewallen
 
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Although a reflected horizontally polarized wave is out of phase with
the incident wave, and this explains the zero far field strength you get
with horizontally polarized waves, I'm not sure this is the relevant
explanation for the lack of ground wave propagation. The reason I doubt
it is that if you do the same analysis for vertically polarized waves,
you find that the net field strength is also zero at zero elevation
angle, except for the special case where ground is perfectly conducting.
So using the same analysis, you'd have to conclude that vertically
polarized waves can't propagate by ground wave, either.

Roy Lewallen, W7EL

Walter Maxwell wrote:
On Sun, 29 Aug 2004 09:31:13 +0000 (UTC), "Reg Edwards"
wrote:


"Richard Harrison" wrote -


There is no propagation of horizontally polarized groundwaves at
all. The low-angle reflected wave is out of phase with the incident
wave.


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With a groundwaves there is no reflected wave and incident wave to get out
of phase with each other. By definition, it is all in the ground down to
one skin depth.



Reg, you are correct, of course, but Richard H. said above, "There is no
propagation of horizontally polarized groundwaves at all. The low-angle
reflected wave is out of phase with the incident wave."

What Richard mean't concerning the 'reflected' wave is that the energy radiated
downward from a horizontal antenna is reflected by the ground, and that
reflected wave is out of phase with the incident wave.

Walt, W2DU