Richard Clark wrote:

Cecil Moore wrote:
Use an antenna analyzer, like an MFJ-259B to locate the
self-resonant frequency.

Vector VOLTmeter?
VECtor Voltmeter?!!!

I don' need no stinkin' VECtor VOLTmeter!

Actually, unlike Tom (who rushes in where angels fear to
tread) I cannot figure out how to use the VVM to make
a valid measurement of what we are trying to measure. If
I cannot figure that out, then the VVM won't do me any
good as Tom's setup didn't do him any good and just
confused him all over again by tricking him into making
his measurement in an SWR = 16000:1 environment. I'm
truly surprised his standing-wave current delay
measurement wasn't zero.

Guess everyone sees the danger in trying to guess what
the results of someone else's measurement will be. Tom
should have measured something around 15.6 degrees. The
fact he didn't sends up a very large red flag.

Another problem is that the delay through the coil
changes drastically between bench isolation and being
installed directly above a GMC pickup's ground plane
because of the enormous increase in coil capacitance
to that ground plane. So the delay through the coil
needs to be measured in the physical environment in
which it is operated. It is virtually impossible to
eliminate reflections from a 75m mobile bugcatcher
system so the VVM can't measure what we are trying
to measure.

The question is: For a well-designed coil, is the self-
resonance method valid for determining the delay through
a coil at HF frequencies below the self-resonant frequency?
Since that's been an accepted way of doing it for more
than a century, I don't see how anyone could object.
--
73, Cecil http://www.qsl.net/w5dxp