Or length, really...
Say you have a vertical that can be any arbitrary length, and you have a
(presumed perfect lossless) tuner at the base of the vertical. What
length should one choose, if you want to operate all HF ham bands?
Obviously, there's lots of folks selling 43 foot verticals these days,
but I suspect that's a length chosen to make sure the impedance isn't
"bad" in the ham bands, when fed with a simple matching network (4:1
transfomer, often with some leakage C) and coax to a tuner in the shack.
Is there a point of diminishing returns in height (e.g. the difference
in performance on, say, 160m, is going to be tiny between 20 ft and
25ft.. it's a "very short" radiator on both).
What about higher band performance (a very long radiator is going to be
much longer than a 1/4 wavelength, so the pattern will start to have
many vertical lobes, which may or may not have a big practical effect).
(The assumption of lossless tuner isn't all that unreasonable, at least
for comparing the radiation performance..)
Jim
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