Dr. Slick wrote:
"But, my point is that you can take a DC measurement anywhere on the
ideal lossless antenna and you will never see 50 Ohms anywhere, only
shorts."

True. D-C resistance of a lossless wire is zero. But, apply 50 watts r-f
power to an antenna adjusted to present 50-ohms resistance at a
particular frequency.

What happens? Our loading, adjusted for 50 watts output, produces 50
volts at an in-phase current of 50 amps.

The 50 watts is being radiated. As far as the transmitter is concerned,
the power might just as well be feeding a dummy load.

There are several reasons a d-c ohmmeter doesn`t read radiation
resistance. Once the ohmmeter`s d-c has charged the antenna, current
flow stops. D-C doesn`t radiate. A d-c ohmmeter doesn`t even measure the
right loss resistance value. Some of the loss resistance in a true
antenna with actual losses, comes from skin effect at radio frequencies,
where the conduction is forced to the outside of the conductors,
decreasing their effective cross-section and increasing their loss. R-F
also has the ability to induce eddy currents in surrounding conductors
and to agitate molecular movement in surrounding insulators. R-F thus
increases loss over that measured by passing d-c through the antenna.

Radiation resistance can be readily measured by using an r-f bridge
instrument. The bridge and antenna are excited by a generator operating
at the same frequency the transmitter will use. The bridge will indicate
reactance in the antenna, if it is not resonant. The null detector for
the bridge is typically a good radio receiver.

Radiation resistance is real though it does not heat the antenna. Loss
resistance is real though it does heat the antenna and its surroundings.

A resistance is a volt to amp ratio in which amps are in-phase with the
volts.

A resistor is a special type of resistance in which the electrical
energy applied to the resistance is converted into heat.

Best regards, Richard Harrison, KB5WZI