>
> To model radials, we must use Real High Accuracy Ground, with NO connection
> to Ground. Read the EZNEC manual
Yes! That is what I need to change. Thank you!
Solution:
I was connecting the radials to ground using EZNEC. I need to create the
radials just above ground.
Page 90 of the User Manual.
"Buried radials can be directly modeled only with EZNEC Pro/4 using an NEC-4
calculating engine (see Buried Wires). With EZNEC, EZNEC+, and EZNEC Pro/2 they
have to be simulated.”
Buried radials with EZNEC have to be simulated. “...model buried radials by
substituting radials just above the ground surface. This does a moderately good
job of predicting the ground system efficiency as well as whatever pattern
modification results from the radial system. With this approach, the High
Accuracy Real ground type must be used. See Connecting to High Accuracy Ground
for more information.”
Page 127 of the User Manual
"With program types other than EZNEC Pro/4 the best way to approximate a buried
radial system is by creating horizontal radials just above the ground, and make
the "ground" connection to the radials. A height of between about 1/100 and
1/1000 of a wavelength is suitable, but in any case no less than several wire
diameters. If a low impedance connection is required, make the radials about a
quarter wavelength or odd multiples long, and avoid lengths approaching a half
wavelength or multiples. These aren't free space wavelengths, however, but
wavelengths for a wire at the radial height. A half wavelength for a wire very
close to the ground will be less than in free space, though. You can determine
the wavelength by modeling a dipole at the height of the radials and adjusting
its length until it's resonant. Be sure you're seeing the lowest (series)
resonance, which for very low wires will occur with a dipole length somewhat
less than a free space half wavelength. The best radial length will be about
half the resonant dipole length.
Radials can easily be constructed using EZNEC's automated radial creation
feature. Above ground radials will show resonant effects more sharply than
buried radials, but will provide a reasonable approximation of a buried radial
system."
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