Mike wrote,


What I have become stuck on is the claim of constant current along the
length of the antenna - or 80 percent as claimed. How does this work? I
don't profess to know much about these matters, but if the current stays
the same, then the voltage must too?

And i still can't figure out how such an efficient antenna "melts". 8^)

- Mike KB3EIA -


Anyone can make a "constant current" dipole, just by making it small
enough in relation to the wavelength of the frequency it's to be used for.
Of course, as has been pointed out here many times, feeding such an antenna
would be difficult to impossible, and bandwidth would be small, but you can't
have
everything.
Some theorists in the late 1940's did some work on the fundamental limits of

small antennas. There are one or two papers available on the web if you search

for "small antennas" with google. People who think they can make a small (in
terms of
a wavelength) single radiator antenna, with good efficiency, and a large
bandwidth,
that doesn't have to resort to feedline radiation to achieve its aims,
would do well to read these papers before making themselves look silly by
claiming
the impossible.
73,
Tom Donaly, KA6RUH