View Single Post
  #104   Report Post  
Old November 3rd 03, 08:44 AM
Roy Lewallen
 
Posts: n/a
Default

Tell us, Cecil, at steady state at one frequency, can a lumped inductor
(presumably like the experimenter's toroid) tell whether it's at the
base of an antenna or simply in series between a generator and load
impedance?

Yes_____

No______

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?

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. And where those coulombs are going, that go into
one end and don't come out the other. Going to the fourth dimension as
virtual photons, perhaps?

Roy Lewallen, W7EL

Cecil Moore wrote:
Yuri Blanarovich wrote:

in other words, the highest current point on the structure is at the
inductor.

That's what W8JI calculated in EZnec, does it make sense? Like 2+2 is
4.5? Why
would inductor "suck" the current up? We should then use "those"
inductors to
suck the current all the way to the top of the whip - perfect antenna?
Cecil, can you 'splain that?



Again, the current can either stay the same, increase, or decrease through
an inductor depending upon where it is located. Has that statement sunk
in on anyone? If you install a coil 1/8WL up on a 1/2WL vertical, the
current through the coil will *INCREASE*. If you install it in the center,
the current magnitude will be the same in and out of the coil and opposite
in phase. If you install it 1/8WL from the top, the current will decrease
through the coil like it does on a 1/4WL mobile antenna.