Cecil Moore wrote:
A 75m bugcatcher coil used on 4 MHz is NOT significantly below
the self-resonant frequency of 9-10 MHz.

Yes it is, but no so far as to have perfectly equal currents at each
end an zero phase shift in current. It is in the neither land between a
Tesla coil (which is still nothing like my mobile antenna, but at least
getting closer) and a idealized lumped component.

THE LUMPED-CIRCUIT MODEL FAILS IN A STANDING
WAVE ENVIRONMENT! In the face of that simple technical fact,
all other discussion is moot. Anyone wishing to validly model a
75m bugcatcher coil used on a mobile antenna is forced to choose
a model that does not presuppose faster than light wave travel
through a 75m bugcatcher coil. It's as simple as that.

Nonsense. You are ignoring the coupling mechanisim inside the inductor.


Tom, with a straight face, I want you to assert that the RF waves
on a 75m bugcatcher mobile antenna are traveling faster than
the speed of light. If it takes 125 nanoseconds for the forward
current wave to make it from the end of the antenna and back
to the feedpoint, then the lumped-circuit model yields invalid
results. TDR anyone?

They are not travelling faster than light.

What you (and the one or two others who seem to agree with you)
repeatedly ignore or forget is magnetic flux couples one turn to
another. A real inductor is always someplace between the two extremes
of something like a radial mode helice (helically loaded whip) and an
ideal lumped component.

Since you have taken the path of totally forgetting or ignoring flux
coupling, you are reaching incorrect conclusions. Using the Tesla coil
model is a good example.

Everyone is freely admitting there is *some* transmission line effect
going on. There is some distrbuted component (a series of inductors
shunted by capacitors) going on.

Everyone (except you) is being careful to qualify remarks by specifying
the inductor is operating well below self-resonance.

If you weren't so pig-headed you could look at the measured data at:

http://www.w8ji.com/mobile_antenna_c...ts_at_w8ji.htm

....and see that as inductors move towards self-resonance they do begin
to display characteristics of transmission lines.

It's too bad in three years you have claimed others made a measurement
error, when in fact the error is in thinking all of the current in a
loading coil slowly winds its way around turn by turn and the magnetic
field linking turns does not cause charges in other turns to move long
before current traveleing at light speed would wind through the copper
path.

Until you stop, put the beer away, and think about this a while you'll
continue to butt your head up against people who KNOW how inductors
behave.

73 Tom