Zero reactance in a wire antenna feedpoint is a necessary but not sufficient
condition for it to be truly resonant. Citing the Antenna Fundamentals, chap
2, page 2-1 of my 16th addition of The ARRL Antenna Book, a resonant wire is
defined as 'The shortest length of wire that resonates at a given frequency
is one just long enough to permit an electrical charge to travel from one
end to the other and back in the time of one RF cycle.'
Clearly, a short wire with a finite pure resistive radiation impedance is
too short physically for the required condition to exist as stated in the
On the other hand, elsewhere in the book, a zero reactance 'resonant'
condition does not mention the required physical length of the wire. If this
is all that is required, ANY wire can be called resonant and there is
nothing to distinguish such wires from a halfwave wire. Somehow this doesn't
sit right with me. What do you think? Do you think that this discrepency
begs for a minor clarifying rewrite?
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