Not sure that I should add to this lengthy theme, but
my empirical experiences on 160m:
(1) An inverted L, 50' wire vertical section in a
tree, about 10 pretty short radials - take that as
reference;
(2) A top loaded 95' vertical with about 200 radials
each at least 150' over a full circle - about 6dB
better;
(3) A 300' vertical with 120 x 1000' radials - to all
intents and purposes identical to (2) :-) !
Antenna (1) was about 50' from a freshwater lake, and
(2) about 400' from (1), both over reasonable (for
northern Ontario) soil. Antenna (3) is about 14km
distant and over mostly rocky soil. Comparative
testing was halted after a relatively short period due
to a wretch stealing most of the remote equipment. It
should resume in the next few weeks with (3) replaced
by a directional array.
I don't think I have 'proved' anything, but I am
convinced that it is (a) very easy to get 25%
efficiency and (b) very hard to get anything
approaching 100%.
73 Roger
VE3ZI
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