"Tdonaly" wrote in message
...
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.
Don't make up a false augument, nowhere do I say that parts of a dipole
does not radiate, soon you will have half the neibourhood up in arms
regarding something I didn't say. As for your parlying the term 'false' so
liberaly it is clear that you were sleeping during class, but then even
those who know little of radiation can have an oponion.
So what is your vision of the future with respect to antenna and are you
doing anything to make that vision come true i.e. walking the walk.or are
your jollies gained by shooting at those such as Cecil that does have the
required knoweledge? On top of all that read carefully regarding'
efficiency' since I have qualified it as ' per unit length'
Best regards
Art Unwin




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.
Lots of words but all meaningless, I never said that I was persueing the
ultimate point radiation suggestion. I
experiment to the point that all antennas regardles of frequency can be made
such that they are rotatable in the horisontal mode which means for 160
meters inovation has to be involved to reduced such a monster such that it
can be rotated around its center point. I HVE REACHED THAT POINT AT THE
PRESENT TIME and am now looking at ways to reduce it further, but maybe the
next generation will achieve that jump.! I fully expect that somebody will
say I have violated a law of old but until then I will continue to use it on
the bands




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.)

I don't see why he should take it! We have lost so many talented people from
this group Tom,Gary Roy and so on
but we are still not at the point where Richard and his followers ( not
Richard Harrison ) pseudo Doktors and what ever have the forum completely to
themselves.
Regards
Art Unwin KB9MZ.....XG