Art wrote,
With regard to efficiency per unit length. It is well known that the ends of
a 1/2 wave dipole can be lopped off without any noticable difference which
can be seen by the area lost under the normal current flow diagrams, so
efficiency can immediatly improved. When shortening the dipole even more we
get a transition to a straight line current flowline inplace of the sino
soidal curve which again shows a further inefficient portion at the ends
that can be lopped of.


Hi, Art,
The above is untrue. Efficiency only has to do with the ratio of radiation
resistance
to total resistance. Also, the idea that the only part of an antenna that
contributes
to radiation is the center part because it carries most of the current is also
untrue.
The claim probably originates from the fact that most antenna parameters can be

calculated given a knowledge of current distribution. It's a false leap of
logic
to conclude that there are portions of a half wave dipole that don't radiate,
though. Since
those areas have high changing charge densities which are associated with
changing electrical fields which..., and so on, they radiate quite well.
I don't think most amateurs want to diddle around with infinitesimal
dipoles, anyway,
Art, which is what they'd end up with if they implemented your ideas. An array
of
infinitesimal dipoles such as you're suggesting would be fun to make, but I
doubt
the wisdom of expecting increased efficiency from it.
73,
Tom Donaly, KA6RUH

(P.S. Art, I hope you don't equate disagreement with ridicule. I reserve all my

ridicule for Cecil since he can take it.)