On Sun, 1 Oct 2006 17:24:17 -0500, "Richard Fry"
wrote:

This subsequent restriction to GRAPHICS (and not to issues of NEC per se)
...

But the GRAPHICS are only plotting what NEC calculated, are they not?

The point of the matter (re-iterated by Roy) is that the graphical
representation is one for wide application (99.9999%) and the
remaining (0.0001%) still have access to the DATA. There is nothing
lost but convenience. True, one may come to some erroneous conclusion
on abstracting the near-in characteristics to the far field
representations. I would challenge them more for their
mis-application than their literal mis-understanding, however. There
is not much demand for 160M operation to the horizon that goes wanting
elaborate modeling. Simple experience eclipses that easily.

To cut to the nut of the matter:
But to bring us back to the major complaint which seems to be that the
Nec engine doesn't model the last few degrees over ground very well
is simply wrong in the first degree (also re-iterated by Roy).

I've been modeling for results at the horizon for as long as I've held
a copy of EL/EZNEC. This and the Brown, Lewis, Epstein data confirm
to within 1dB as I've reported on more than one occasion. This is a
validation in the absolute, not relative sense; and to a probable
higher degree of accuracy than the average Ham pursues or could
obtain.

73's
Richard Clark, KB7QHC

"Richard Clark" wrote:
I've been modeling for results at the horizon for as long as I've held
a copy of EL/EZNEC. This and the Brown, Lewis, Epstein data
confirm to within 1dB as I've reported on more than one occasion.
_____________

Even the demo version of EZNEC, used judiciously, can do that.

The link below leads to a screen clip of EZNEC output windows. EZNEC
parameters were set for the 1937 BL&E study for a 90 degree monopole, and
the r-f ground produced by ~113 radials each about 0.41 lambda long

EZNEC shows an h-plane field of 189.76 mV/m at 1 mile for 1 kw of applied
power. The BL&E paper shows about 191 mVm for those conditions (Figure 30).

The EZNEC calculation for these conditions differs from the BL&E paper by
less than 0.06 dB.

http://i62.photobucket.com/albums/h8...EC-2Emulat.gif

RF

PS: And many thanks to Roy Lewallen for making a demo version of EZNEC
available.