No, that's not what I asked. Let me try again.

I have an antenna whose feedpoint impedance I measure as R + jX. I put a
lumped (physically very small and short) coil in series with it and
drive it with a generator. You and Yuri say that the current going into
the coil is different from the current going out.

Now, I replace the antenna with a series resistor and capacitor or
inductor which also has a terminal impedance of R + jX ohms. My question
is, does the inductor now have equal currents at its two terminals, and
why or why not?

Roy Lewallen, W7EL

Cecil Moore wrote:
Roy Lewallen wrote:

If you answered "yes", please explain how and why, and how we'd
calculate the current through and voltage across the inductor. If we
moved it an inch up the transmission line from the antenna base, can
it still tell?


Forget about an inductor becoming conscious. The impedance looking
into a six foot whip is the same whether the coil is there or not.
The impedance looking into the bottom of the coil is certainly not
the same as looking into the six foot whip. I suspect this can be
proven by modeling a mobile antenna and then moving the source point
from just under the coil to just above the coil.

If you answered "no", please write us the equations showing just how
much the current should be expected to be different from one end of
the inductor to the other.


The current will be approximately the same as at the two points
of wire it replaces in the antenna without the inductor. I earlier
asked you a question that you seem to have missed. Do you agree
or disagree with Fig 9-22 of ON4UN`s "Low-Band DXing", included
on Yuri`s web pages.?

And where those coulombs are going, that go into one end and don't
come out the other.


You can answer your own question. Where do the coulombs go that enter
one end of a 1/4WL stub and don't exit the other end? Please stop
using lumped circuit analysis on distributed network problems. You
know and I know that it doesn't work.

Roy Lewallen wrote:

No, that's not what I asked. Let me try again.

I have an antenna whose feedpoint impedance I measure as R + jX. I put a
lumped (physically very small and short) coil in series with it and
drive it with a generator. You and Yuri say that the current going into
the coil is different from the current going out.

Yes, just as the current going into a 1/4WL stub is different from the
current going out. If you use an inductive stub, is the current the
same going in as going out? If so, you have invented faster than
light transfer of current.

Now, I replace the antenna with a series resistor and capacitor or
inductor which also has a terminal impedance of R + jX ohms. My question
is, does the inductor now have equal currents at its two terminals, and
why or why not?

You have replaced a distributed network with a lumped circuit. If the
lumped circuit model worked on distributed networks, you would be right
and there would be no need for a distributed network model (but there is).
--
73, Cecil http://www.qsl.net/w5dxp



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