K7ITM wrote in
:

On Mar 17, 12:41*pm, Owen Duffy wrote:
"Tom Donaly" wrote
innews:QoQvl.13889$8_3.3071@f
lpi147.ffdc.sbc.com:

....
On the other hand, you may well discover some insights looking at it
in a different way, so I hope my comments won't discourage you from
doing that!

My real objective is to model b) in NEC.

Trying to understand a) and to deconstruct it is part of an approach to
finding a solution to b).

The 'stub' in a) cannot simply be replaced by a s/c TL element, so that
suggests that a s/c TL element is not a solution for b) either.

The last configuration with the triangular / diamond configuration of the
phasing line seems to work in an NEC model, and the deconstruction
suggests that having a half wave of conductor is fundamental, and that it
need not be in the form of a two wire TL.

I have also tried removing the 'stub' from a) and using a half wave TL to
drive segments each side of the gap from each other. If the segments are
close to, but not the last, this does produce a current distribution that
is not 180° out of phase, but it does not produce the almost perfect in-
phase outcome of modelling the wire structure. Nevertheless, playing with
the length of that TL, being very close to half wave in length is
essential to overriding the natural tendency to out of phase currents.

This hasn't solved the problem of modelling a coaxial configuration,
expecially where the coaxial section was coax cable, apart from excluding
some approaches as invalid.

Owen