AB7E said:
"...nothing we do can change the effect that the ground has on takeoff
angle."
Nothing we yet know about. I don't believe I'm the only one who has
spent some effort trying to find a way to achieve low-angle radiation
for a low horizontal antenna or for a vertical antenna over poor ground.
I even wrote a QST article (or was it the Antenna Compendium?) on the
failure of one promising trick for horizontal antennas. I believe Les
Moxon addressed the issue by suggesting aiming into a lossy forest with
a particular geometry.
I never worry about takeoff angle, which I take to mean the angle of the
maximum lobe in the elevation plane. Communication takes place at angles
determined by path distance, ionospheric height, ionospheric tilt, and
probably more. It does not necessarily occur where any particular lobe
is located. I generally pick what I think is a representative low angle,
usually 5 degrees, and compare gain for all antennas I'm considering there.
I just posted an update for my ground probe calculator. I probably
should write something up here about it since recent developments bear
directly on the problem of determining losses for ground radials, either
buried or elevated.
I'd attach a nifty plot but this list won't accommodate it. You can see
a few here:
https://k6sti.neocities.org/gnd
Brian
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