If you had made this model with EZNEC, you would have seen a warning
that the segment length is shorter than recommended. And you could have
entered the dimensions directly in inches (or immediately converted
between meters and inches). The free demo program is adequate for this
model, providing you don't want more than 20 segments.

Roy Lewallen, W7EL

Frank wrote:

I should have read the manual before modeling, but I was so concerned that
the feed-point be near the bottom. Changing the segmentation to 17,
removing the LD card, and reducing the radius to 0.125 ", calculates the
feed-point impedance as: 0.123 - j3286. I considered Jim's calculation of
0.37 - j8170 to be far too reactive. The fact is these points are so close,
when observed on the Smith chart, as to be virtually identical.

Analyzing a shunt L/series C matching network, with inductor Q at 300,
indicates a loss of 21.5dB with 30 kV RMS at the base of the antenna (1.5 kW
into the matching network). (In the case of 0.37 - j8170 the loss is 21.8
dB, with 42 kV at the base). These voltages are so large, I am beginning to
wonder if I goofed again! The losses, at least, are the same order of
magnitude as Roy's calculation.

73,

Frank