Radiation Resistance.

Roy, what an excellent, well needed exposition, in plain English, addressed
mainly to professionals who should know better, and are guilty (dare I say
it) of obtaining money under false pretences.

You omitted only "DISTRIBUTED radiation resistance", a term essential to but
absent from this newsgroup. It's probably also absent from Terman and Kraus,
the latter I have never read. It's an aid to clear logical thought.

It should be used whenever radiation resistance is compared with conductor
resistance, inductance, capacitance, etc., of elongated wires and loading
coils.

As an example, it so happens that the distributed, end-to-end, radiation
resistance, Rd, of a half-wave diopole is exactly twice (easily proved) the
feedpoint resistance of around 72 ohms.

The radiating efficiency of a half-wave dipole is then, very simply and
accurately -

Efficiency = 144 / ( 144 + overall HF conductor resistance )

although some old-wives may wish to argue about it on the grounds that it's
far too simple.
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Reg, G4FGQ