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Old April 3rd 06, 07:37 PM posted to rec.radio.amateur.antenna
K7ITM
 
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Default Current through coils

Thanks, Tom.

In fact, let's get back to something very basic about antennas.

Acceleration of CHARGE results in electromagnetic RADIATION.

RADIATION impinging on a receiving antenna (and on anything else that
freely transports charge) causes acceleration of CHARGE within that
antenna.

So when we are talking about antennas, it is very appropriate to be
talking about charge, and exactly what happens to it to move it around
and to accelerate it as a function of time, everywhere in the
structure.

A voltage applied to the feedpoint terminals of an antenna causes
CHARGE to be put into motion. Accumulation of CHARGE along the
conductors--the distribution of charge as a function of time and
space--in turn results in electric fields in the vicinity of the
antenna. Motion of charge results in magnetic fields in the vicinity
of the antenna. Capacitance and inductance are manifestations of the
electric and magnetic fields, respectively. Taken as a whole, the
motion of charge and the resulting electric and magnetic fields give
rise to waves: the waves, too, are manifestations of the electric and
magnetic fields. ALL of these are consistent with each other, and to a
very good approximation agree with the descriptions worked out by
Faraday, Gauss, Maxwell and all many years ago. (We don't need quantum
theory to be talking about performance of an 80 meter mobile antenna!)

Please, let's keep it straight that the motion of charge is FUNDAMENTAL
to all this analysis, and everything else will fall out very nicely
from an accurate accounting of the motion of charge within the system.
It is NOT irrelevant at all; it is at the very heart of the operation
of ALL antenna systems.

Cheers,
Tom