Keith Dysart wrote:
On Dec 9, 1:24 am, Cecil Moore wrote:
Keith Dysart wrote:
How is it that this exhibits transmission line behaviour?
The equation for a single-wire transmission line over
ground is well known to be Z0 = 138*log(4D/d)

Ahh. So the coil and the ground plane make the transmission
line, and the two terminals are between the coil and the
ground plane.

Yes, it is an unbalanced transmission line.

Keith, I want to commend you on having an open-mind and
an ability to listen to what I am saying. That is the
best way to get down to the technical facts. Others on
this newsgroup are closed-minded with an inability to
listen presumably because they already know all there
is to know.

But I did not see D or d in the spreadsheet which computed
Z0.

Those must be secondary effects or else Dr. Corum would
have included them. Of course, Corum's coils are operated
against a very large ground plane. Corums's equation (50)
and (51) for Z0 are only concerned with the diameter of
the coil and the wavelength. However, the diameter of the
coil is roughly equivalent to the diameter of the wire
in a straight-wire configuration.

I'd expect that repeatability will require the same
orientation of the coil with respect to the ground
plane. And the same height.

Absolute repeatability is not necessary for conceptual
technical truths to emerge.

Of course this horizontal coil has a completely
different relationship to the ground than it would
when installed vertically in an antenna? Will the
results of the measurement be at all applicable?

If the range of results is 15ns to 35 ns, that will
be a clue that 3 ns is impossible. The absolute results
are not important. The spread of measurement values
will be enough to prove that 3 ns is outside of any
3 sigma limit.
--
73, Cecil http://www.w5dxp.com