Jim Kelley wrote:
The advantage to using pulses is that they are 'broadband' - they don't
have "A" frequency. The inductance and capacitance of the system are
unaffected by the small signals one impresses upon it.

But we are not interested in the phase delay for all
those other frequencies. We are only interested in the
phase delay at one particular frequency. And since we are
talking about distributed networks and not lumped circuits,
the inductance and capacitance of the coil does change with
frequency. Whatever measurements we make need to be made
at the frequency of operation.

The antenna behaves physically in exactly the same way whether or not it
happens to be 'occupied' by waves, standing, sitting, or whatever during
measurement. If you want to know how long it take an electromagnetic
wave to traverse a conductor in any shape or configuration, you pulse it
and measure how long it takes, either to get from one end to the other,
or to be reflected back from the other end.

If the pulse is not at the frequency of operation, the results
are hardly useful at all since the response of the loading coil
is frequency dependent.

So we are back to the original question. How can the delay through
a mobile loading coil be measured at the frequency of operation
in a standing-wave antenna?
--
73, Cecil, w5dxp.com