Reg:

[snip]
For calculating convenience, we assume the radiation resistance, Rrad, is
uniformly distributed along the length of the wire and is 140 ohms which
has
been calculated from its dimensions. It only has two - Length and
Diameter. But for a half-wave dipole it is always about 140 ohms. Wire
diameter has a relatively small effect on Rrad.
[snip]

Reg, in your model, is your *assumption* "for calculating convenience" that
radiation
resistance is uniformly distributed along the antenna structure, i.e. the
transmission line
that represents the antenna in your model, supported by any theory or is it
just a
mathematical *fit* to the data?

For example, one could *assume* literally any analytic distribution of
radiation resistance
along an antenna's length, for instance sinusoidal, catenary, exponential,
triangular, etc...
and come up with a value/function for that particular distribution that has
the equivalent
effect of a lumped value placed at the antenna feedpoint. What is so unique
about uniform?

Why do you think *uniform* is any better than any other distribution of
Rrad?

I have no axe to grind here, just curiosity...

Best Regards for the New Year.

--
Peter K1PO
Indialantic By-the-Sea, FL.