Roy Lewallen wrote:
Resonance has everything to do with impedance. Resonance is defined as
any frequency at which the impedance is purely resistive; ...

In the distant past, when I had a dinosaur for a pet, resonance
was defined as the frequency at which the impedance is a purely
low impedance. The frequency at which the impedance was a
purely high resistance was known at the anti-resonant point,
the exact opposite of resonance, and indeed, it was the exact
other side of the SWR circle on a Smith Chart.
--
73, Cecil http://www.qsl.net/w5dxp