Tom Bruhns wrote,

(Snip)

And still, all this does NOTHING to tell us WHY the antenna's
reactance reaches maximum at that particular frequency. Again, maybe
I missed it, but I didn't see anything in your swr circles and
reactance arcs explanation that even mentioned frequency.


In Constantine Balanis book _Antenna Theory Analysis and Design_
second edition Section 8.5 page 411, there are a couple of charts of
resistance and reactance that illustrate the original question. On
the facing page (page 410) equations are given for R and X at
current maximum points on a dipole. If these equations are
correct it's not hard to believe that their respective maxima don't
coincide since the equations are different. If anyone wants to
understand where the equations come from he can read chapter
eight in all its gory entirety. It's not simple and requires more than
just a familiarity with a Smith chart. Cecil should read before he
thinks.
73,
Tom Donaly, KA6RUH