Current through coils
Cecil Moore wrote:
And there's no such thing as current imbalance based on standing
wave currents being different at each end of a loading coil.
"Current imbalance" is a concept that doesn't apply to standing
waves. "Phase rotation with position" is a concept that doesn't
apply to standing waves. Standing wave current is NOT ordinary
current. It is the superposition of two ordinary currents.
You two are so close to agreement. Standing waves have a current that
varies with position. The fact that the EZNEC simulation of a loading
coil shows differing current in a situation that is a fairly pure
standing wave situation (more energy bouncing up and down the antenna
than is radiating from it) means that the RMS current will vary along
the standing wave. And, since the simulation shows a different
current magnitude at the two ends of the coil, a significant part of a
standing wave cycle must reside inside the coil (more than the
physical length between the two ends of the coil would account for).
In one case (the highest frequency one) the phase of the current even
reverses from one end of the coil to the other, as well as an
amplitude variation, indicating that a standing wave node occurs some
where inside the coil, and the two ends are on opposite ends of that
node. If the two currents had been equal, but 180 degrees out of
phase, the node would have been in the center of the coil.
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