"Roy Lewallen" wrote in message
...
christofire wrote:
. . .
* HP is less effective than VP for VHF communication with mobiles because
the ever-present ground reflection has reversed polarity (i.e. it's in
antiphase with the signal propagating over a direct path).
. . .

Reflection of a CP wave results in a reversed CP wave only when the
reflection is directly normal to the reflecting surface. That's not at all
the case for typical ground reflections. What you actually get from ground
reflections is an elliptically polarized wave, likely having the same
sense as the impinging wave. In experiments I ran about 35 years ago, I
found nearly linearly polarized waves resulting from reflection of a CP
wave from a vehicle top.


No doubt, but what I wrote above was about horizontal and vertical _linear_
polarisations, HP and VP. I did wonder after I sent it if 'polarity' would
be misread as polarisation.

Chris