Cecil Moore wrote in message ...
Tom Bruhns wrote:
Cecil Moore wrote:

alhearn wrote:
My question is what determines where that peak occurs?

Mathematically, it will be where the SWR circle is tangent
to the reactance arc.

That is not in general true; do you have reason to believe it's true
for the impedance of a dipole?

When the dipole is at maximum feedpoint reactance, can the SWR be
calculated? Of course. Will that point, when plotted on a Smith Chart
lie on the SWR circle? Of course. Will it also lie on a reactance arc?
of course. Will the SWR circle be tangent to that reactance arc?
Of course.

I'm sorry, Cecil, but you lost me there. For any given SWR circle,
there are only two (complex conjugate) points at which reactance arcs
are tangent. Why would we think that the point of max reactance on
the antenna impedance curve will necessarily be at the point of
tangency? The antenna impedance arc of the simple dipole I modelled
indeed does not lie tangent to the max reactance arc at the same point
as the SWR circle that's tangent that reactance arc.

In any event, I don't see that this tells us anything about _why_ the
dipole shows max reactance at that particular frequency.