On Sep 2, 7:34*pm, Cecil Moore wrote:
Dale Parfitt wrote:
I have repeatedly asked you to supply us with your original quote from
W8JI's page concerning a straight radiator is the best.

Quoting W8JI's web page:
"How do we make a small antenna as efficient as possible?"
"... we make the antenna as large and straight as possible in a line.
We don't fold, bend, zigzag, or curve the antenna especially in the
high current areas."

I don't know what the fuss is all about. Transmission line
currents don't radiate (much) because they are out of phase.

Random folding of an antenna more often than not introduces
transmission line currents into the antenna itself - not
good for radiation purposes.

Transmission line currents cause destructive interference -
that's good for transferring power from one place to another
but not good for radiating RF.

There are certain special-case antennas where folding occurs
without introducing destructive interference, e.g. a 1/2WL
folded dipole or a full-wave quad where the wires are a
large enough percentage of a wavelength apart so they don't
cause near-field destructive interference.

Cecil
It is not related to volume. It is because they are both closed
circuits thus all radiation
can be accounted for i.e. all the circuit wire contribute to
radiation. Any length less than 1WL does not !
If one introduces lumped loads then you have to cancel them, no
problem. Maxwell clearly stated that we are dealing with distributed
loads only, ie root L.C. The inclusion of volume is only because some
people cling to the magnetic field theory as opposed to the particle
theory. Equilibrium allows for multiple shapes and sizes for
achievement
Regards
Art


Hint: RF radiation cannot be understood without understanding
constructive and destructive interference in the near, medium,
and far fields.
--
73, Cecil, IEEE, OOTC, *http://www.w5dxp.com