I apologize. I read and was referring to the same quote, and interpreted
it to mean that the first measurement was made with the coil at the base
of the antenna. So where was it -- 78" from the bottom?

Roy Lewallen, W7EL



Yes,
mast 78" - coil - 38" top whip
we keep saying, looking at typical mobile antenna with loading coil about 2/3
up the quarter wave radiator. The lower the frequency, more loading, more
pronounced effect.

Caution, using toroid current transformers with scope leads would detune the
antenna setup and introduce errors. You can get away with this at the base, but
any stray capacitance up the radiator will detune it and skew the results.
Need to use thermal RF current ammeters or current probe with detector and
small meter together, no wires.

Yuri, K3BU