Cecil Moore wrote:
Given a 102 ft. Dipole at 40 ft. fed with 450 ohm ladder-line
and used on 3.8 MHz, for a ladder-line length between about
25 ft. and 100 ft., the resistance looking into the ladder-line
^^^^^^^
is about equal to the length of the ladder-line. Thus for 25 ft.
of ladder-line, the impedance looking into the ladder-line is
about 25+jXL1. For a ladder-line length of 50 ft., the impedance
looking into the ladder-line is about 50+jXL2.

I misspoke above. "100 ft." should have been "50 ft."

For a ladder-line
length of 100 ft., the impedance looking into the ladder-line
is about 100+jXL3.

It is true that the resistance for 100 ft. of ladder-line is about
100 ohms, but it is 100-jXC, not 100+jXL. Sorry for the faulty memory.
--
73, Cecil, W5DXP