On Aug 28, 9:23*pm, Art Unwin wrote:
A long time ago there was a arguement both on this group and on
E ham with respect to the function of a coil with respect to replacing
missing degrees of a wavelength.

The purpose and function of a loading coil used with an electrically
short antenna is to offset the capacitive reactance of the short
radiating section. Otherwise it will not accept much power from a
transmitter or deliver much power to a receiver, due to a very high
mismatch to common types of transmission line connected to its
terminals.

Check this using a simple NEC model. The model will have ~ the same
radiation resistance, radiation pattern, and gain in dBi whether or
not a loading coil at the feedpoint makes the antenna system resonant,
other things equal.

J. Kraus states in the link below that the radiation resistance of a
loaded vertical (for instance) is nearly the same as that of an
unloaded vertical of the same height.

That a loading coil contributes "missing degrees" to resonate a short
antenna is rather a specious concept.

http://i62.photobucket.com/albums/h8...ndVertical.gif

RF