"dansawyeror" wrote in message
...
"a 1/2 wave segment is resonant no matter where you feed it." That allows
for a large single coil to 'tune' one arm of an antenna and for the other
to be adjustable.

Simulation predicts the impedance will change when it is not feed at the
center, it appears to go up as the feed point is moved.

I will play with the segmentation and see what happens.

Thanks - Dan

Dan,

As for NEC segmentation. "0.05 wavelengths per segment is preferred, but
can be as long as 0.1 wavelengths. Segments shorter than 0.001 wavelengths
should be avoided". From L. B. Cebik's "Basic Antenna Modeling: .....". In
most cases all segments within a structure should have equal length
segmentation. Where antenna models become very large, with 1000 segments or
more, there are work-arounds which allow for uneven segmentation without
introducing errors. The problem with large numbers of segments is that
processor time increases dramatically.

I see nothing wrong with using one loading coil in a dipole. The effect is
simply the same as an off-center-fed dipole.

73,

Frank