Roy Lewallen wrote in message ...
It's not clear to me what's meant by the voltage (presumably relative to
ground) at the tip of a dipole. Suppose it's a quarter wavelength above
ground. How would you measure it? Or, how would you measure the voltage
at the top of a quarter wavelength vertical?

Roy Lewallen, W7EL

Indeed... Or putting it another way, the potential between two points
does not have a unique value in the presence of a time-varying
magnetic field, which certainly is the case for a radiating dipole.
If you measure the voltage drop along the wire, it's essentially zero,
so along the wire the voltage between the end points of the dipole is
essentially the same as the voltage across the feedpoint. The only
difference between the ends and the feedpoint is due to I*R drop in
the wire. The voltage at the top of Roy's vertical, made out of
fairly large diameter aluminum tubing, is essentially the same as the
voltage at the bottom of that tube, if you measure along the tube.

It would be better to talk about electric field strengths in the
vicinity of the dipole. You could find the potential along a path
from the field if you wished.

(I'm recalling that Roy turned on a lightbulb in my head quite a few
years ago about this. And I'm sad that Kevin, W9CF, doesn't jump in
on things like this very often these days, though I can understand
why.)

Cheers,
Tom