Richard, why don't you just say that the angle of elevation of the
radio path has nothing whatsoever to do with the type of transmitting
and receiving antennas, or the directions in which they may be
pointing or elevated, or even the operating frequency.
When communication has been established between A and B, the angle of
elevation depends only on the locations of A and B on the Earth's
surface, on the number of hops, on the height of the ionospheric
layers, and on the slope of the layers.
The elevation angle is determined purely by trigonometry.
It tends to be the same at both A and B. There may be simultaneously
more than one path and therefore more than one angle. In which case
multi-path distortion and fading occurs.
Received signal strength depends on the two antenna gains in the
direction of the path. The take-off angle predicted by Eznec-type
programs is an altogether different thing. It depends on reflections
from the ground in the vicinity of the two antennas. It does however
have an effect on received signal strength but is of use only when the
locations of A and B and all other geographic and ionospheric
variables are known. They seldom are! As are ground conditions.
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Reg, G4FGQ.
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