Roy Lewallen wrote:

As a side note, Brown, Lewis, and Epstein's sparse radial results can be
matched reasonably well with NEC-4, but it does require a fair amount of
ground constant adjustment for various numbers and lengths of radials.

Mobile mounted whip antennas fare even worse relative to simple textbook
models. I don't have any experience with comparison of computer models
with actual measurement. Those results should depend on the care with
which the model is constructed and the amount of influence the ground
has on the impedance.

I would figure that getting an accurate ground influence in an antenna
design program would have to be a daunting project, indeed.

While installing my bugcatcher, I did a lot of it in stages, noting the
positive influence on the results. My thinking at this point is that the
make and model, and the size of the vehicle would be critical for the
model, and small changes go a long way.

What's more, the more efficient and narrow the antenna, the more effect
the changes have. Given that a good setup always involves a lot of
custom work like bonding and turning potential radiators like the
exhaust system into more bonded area, it is a really tough exercise.

- 73 de Mike N3LI -