On Nov 27, 10:46*pm, Richard Clark wrote:

When I observe the operational characteristics of EZNEC (you report
you use it above) AND I observe that it does not offer a Near Field
analysis for Mininec r-f ground (as you report you use above) THEN I
have to wonder how you arrive at a figure of 72 mV/m (as you report
you obtained above). Other than version differences or updates in the
program that supercede mine, I rely on the advice found in the Help
manual provided:

Near field analysis is disabled when MININEC-type ground is selected.
...Use some other ground type for near field analysis.

Obviously, near-field analysis was not disabled by/in EZNEC for my
model definition. The surface-wave value of 72 mV/m at 1 km for 1 kW
of radiated power is shown in the screen clip I linked to in my first
post about this.

Also consistent is the complete absence of radials in your model - the
hallmark (cogent) research of BL&E's "Ground Systems as a Factor in
Antenna Efficiency."

The r-f loss of the radial system is accounted for in my model by the
two ohms of resistance inserted between the base of the monopole and
ground, as shown in my screen clip. This two ohms is approximately
the r-f loss of a set of 120 buried radials, each 1/4-wave in physical
length.

The peak gain of the elevation pattern in my model (see my screen
clip) is consistent with such a ground loss and the selected ground
conductivity, so this approach appears to be valid.

Hopefully Roy Lewallen will weigh in, as he has time, to comment on
the methods and results of our two analyses -- although probably Roy
will need more details about your model construction than you have so
far been willing to provide.

I will be content to let the chips fall where they may.

RF