[Antennas] Re: Shortened antennas

[Roy Koeppe]

About...

"Need help from some of the experts on the list.  I know if I wind 1/2
wave of
wire as a helical element I should realize about a 12-15 ohm impedance
and
the element
would appear as if it was electrically 1/4 wave.  If I take two of these
elements
and feed between them I would have a dipole.  Now here is where I need
help.  If I wind
each of the elements as "electrical" 5/8 waves and feed the two elements
at
the center
it seems to me this would "act" like two 5/8 waves as a two element
colinear.  This
could be rotatable as a double extended Zepp.  The question is
this....what
would the
center impedance look like?

For 40 meters this would be about 160 feet of wire on each half and
should
work as
a rotatable DEZ and work 80-10 meters just as my full size DEZ on 40
presently works.

All help would be appreciated."

I believe your premise is incorrect. Pattern and gain from elements such
a 5/8 wave are derived from actual physical length of such elements, and
not electrical resonance. The antenna you describe would exhibit similar
pattern and gain to that of a normal half-wave dipole.

Others??

73,    Roy      K6XK/0