Cecil Moore wrote:
wrote:

What Cecil needs to do is bias the coil with a DC bias current that
safely exceeds the peak RF current.

Then he would have RF current flowing in only one direction.


I should have said: have the RF current wave flowing only
in the forward direction.Wes knew what I meant.

I think a lot of the contention on this subject is based on little
more than such multiple meanings for common term, "current".

When you talk about current flowing, you seem to be thinking of
current waves traveling along a conductor. Others seem to be saying
"current" and thinking of charge movement. I think that only the
second is technically correct (current is the movement of charge, not
the traveling wave or standing wave pattern in that movement), but I
think I understand what you are picturing. We switch to the short
hand concept of calling a pattern of current changes a current every
time we make an AC current measurement and refer to it as a non zero
value, as we do with amperes (RMS).

Standing waves involve no net wave travel in either direction, though
anywhere except at the current nodes, charge is certainly moving back
and forth along the conductor, during a cycle. Thus, there certainly
are instantaneous currents in both directions (depending on location
and instant) along any conductor sustaining a standing wave,
everywhere, except at the current nodes. And everywhere, except at
voltage nodes, half way between current nodes, charge is piling up (as
electrons move toward every other current node) and spreading out as
electrons moves away from the remaining current nodes) creating
voltage changes.

Traveling waves have a very similar charge movement as that which
takes place half way between the nodes and peaks of the standing wave
pattern. But there are no nodes or peaks, so the current swings
between the same 2 values, everywhere along the conductor. Charge
arrives from one direction, instead of from both directions and leaves
in the other direction, each half cycle. Every other half cycle, the
directions of arrival and departure reverse, even though the wave
always moves in one direction. I am talking about conduction in wire,
not EM waves in space, here.

This current (movement of charge in either a standing wave or a
traveling wave) creates H field and the changes in that H field can be
monitored with a current transformer. But at any single point,
current measured with a current transformer has no way of knowing if
the current changes seen are the result of a standing wave or a
traveling wave. In both cases, charge is seen to be moving in
alternating directions. But if you slide the current transformer
along the conductor, the current magnitude will vary if standing waves
are responsible for the current, and remain, essentially constant, if
traveling waves are its source.

I apologize for stating the painfully obvious, but when basic
terminology is the cause of misunderstanding, it sometimes helps to
back up a step in the direction of a more basic view to uncover the
origin of the misunderstanding.