Cecil,

I don't remember why you chose a frequency of 5.89 MHz for all of your
analysis, but in any case I believe that frequency is slightly out of
the 75 meter band. The FCC will be calling. 8-)

I tried to adjust the frequency downward, but the segment length limit
is reached for the coil model. I redrew the coil with only six segments
per turn, rather than eight. Now the frequency can be lowered to about
3.94 MHz without EZNEC guideline check warnings.

In order to get the 90 degree phase curve I extended the horizontal wire
to about 55 feet. (not sure why this matters if the antenna is purely a
terminated traveling wave antenna, but, hey, no loose ends.)

The result from EZNEC is that the phase shift in the coil is about 9
degrees.

You might observe that this shift is a bit smaller than the "tens of
degrees" noted below, and it is also smaller than the guru-inspired
transition point of 15 degrees.

I would like to model a coil more typical of common use than the strange
beast you designed, but the segment length limits in the NEC engine seem
to preclude such models. (I have never seen a mobile coil that is 12
inches high, 6 inches in diameter, with 2 turns per inch.)

If I was the cynical sort I might think that your choice of coil
dimensions and frequency were picked to get a phase shift of 16 degrees,
which is just over the guru limit. But since I am a straightforward kind
of guy I won't think such thoughts.

73,
Gene
W4SZ

Cecil Moore wrote:

Technical facts *are* a deeply personal issue with me. So I ask
you the same question he When are you going to correct the
technical errors on your web page? The delay through a 75m
mobile bugcatcher coil is tens of degrees, not faster than the
speed of light.