>It isn't clear to me whether my EZNEC+ v4.0 can use the High Accuracy
Yes, it can. EZNEC+ allows more segments, and I think, circular
polarization... but both EZNEC 4.0 and EZNEC+ 4.0 allow the Real, High
Accuracy (also called, I think, Sommerfield-Norton) ground type.
That said, I know you're trying to solve a modeling problem, but once
you get the modeling problem solved, don't implicitly trust the
model... the comments in the other thread are really pretty relevant.
No ground model you can use in EZNEC+ will correspond very closely
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