dansawyeror wrote:

"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.

Absolutely true! But, what does feedpoint impedance have to do with
resonance? ... NUTTIN!