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Old April 11th 06, 01:13 AM posted to rec.radio.amateur.antenna
Richard Clark
 
Posts: n/a
Default Current across the antenna loading coil - from scratch

On Mon, 10 Apr 2006 20:52:06 GMT, "Tom Donaly"
wrote:

Not everyone is happy with the term "displacement current." Albert
Shadowitz, in his book _The Electromagnetic Field_, has a chapter
entitled "The So-called Displacement Current." The term isn't in
the index to Feynman's _Lectures on Physics_. (At least I couldn't
find it.) All that is academic to the fact that AC current seems to
be able to make its way through a capacitor with no more opposition
than the capacitive reactance. Fortunately, no one on this
newsgroup has any objection to the way the term is commonly used.


Hi Tom, and others,

The "labeled" currents span a much too small arena. There are also
the induced currents (no, not necessarily from flux linkage) and
convection currents (which IS the primary correlative to the induced
current).

The convection currents are possibly the only current that attain the
speed of light velocity. The others are so astronomically slow, that
it is arguable to say that any current (electron/hole transport) in a
wire is any more significant than that that is supposed to never cross
through the dielectric of a capacitor.

In other words, the displacement current is labeled fictitious because
no electron ever moves from one plate to the other. Now, if we simply
substitute solid gold for that dielectric (still maintaining the same
plates); then no electron ever makes it from one plate to the other -
and yet current flows in the entire AC circuit by proportion to the
impedance presented to it by either the dielectric capacitor, or the
gold capacitor.

This, of course, illustrates the corruption of usage in the term
"current."

73's
Richard Clark, KB7QHC