RadioBanter - View Single Post - Current across the antenna loading coil

April 7th 06, 01:59 PM posted to rec.radio.amateur.antenna

wrote:
A pure inductance would have no current difference at each end.

Hard to prove by measurements since a pure inductance doesn't
exist in reality. It's like saying there's no loss in a lossless
transmission line which is true by definition.

One way to prove the coil does not replace missing length is to simply
move the coil to a new location in a fixed height antenna. If the coil
looked like 40 degrees, it would resonate the antenna no matter where
it was installed.

The coil occupies a different number of degrees depending upon
its location in the standing wave environment. That's why the
resonant frequency of a bugcatcher system increases as the
coil is moved up from the base. In a one wavelength standing
wave system, if the coil is installed at a node, the currents
at each end of the coil will be ~180 out of phase, i.e. the
two currenets *appear* to be flowing in opposite directions at
the same time.
--
73, Cecil http://www.qsl.net/w5dxp