"John Popelish" wrote:
Cecil Moore wrote:
There is no useful phase information in standing wave
current. Therefore, standing wave current cannot be used
to determine the percentage of a wavelength that is
occupied by the coil.

I think I disagree with this. A standing wave has one of two phases
with respect to time, but the two waves traveling through both the
antenna elements and any loading coils do have phase shifts, both with
respect to time and with respect to position. But when the two waves
are superposed, all that is left of this phase information is phase
with respect to position. The phase shift of both the single
direction waves can be inferred by the shift in position of where they
combine to form a node (if you make the (reasonable?) assumption that
the delay in both directions is equal.

I don't disagree with you so I need to rephrase my apparently
poorly worded statement above to make it more understandable.

There is information about this in the amplitude versus position of
the standing wave. But the only very definite points in this
variation are the nodes, so is the length is less than a half
wavelength, you have only the node at the end to work with, so you
have to use the sinusoidal amplitude curve to work with.

Or the velocity factor of the traveling waves can be measured by the
interference pattern they produce as a standing wave. One cycle of
the standing amplitude wave has to occupy the length that carries one
cycle of the traveling wave.

I agree, one can use knowledge and indirect methods. That's
exactly what I do and have been recommending. You and I seem
to be in agreement.
--
73, Cecil, W5DXP