"Roy Lewallen" wrote in message
...
Frank wrote:

Repeating what was previously posted. The following model treats a 1
meter (perfect conductor) monopole, of 0.814 mm diameter, connected to a
perfectly conducting ground. I have applied a vertically polarized
incident E-field of 1 V/m (peak). The base of the antenna is loaded with
the antennas complex conjugate of 1.747 + j823.796. NEC2 computes the
current through the load as 0.2863 Amps (peak), which is 0.5001 V peak.
This appears to agree with Reg's program.
. . .

Possibly someone can point out if there are any errors in the following
code:

CM 1 Meter Vertical
CE
GW 1 50 0 0 1 0 0 0 0.000814
GS 0 0 1
GE 1
GN 1
EX 1 1 1 0 90 0 0 1 1 1
LD 4 1 50 50 1.747 823.796
FR 0 3 0 0 19.9 0.1
RP 0 181 1 1000 -90 90 1.00000 1.00000
EN

You've specified a plane wave of 1 V/m peak arriving in a horizontal
direction over a ground plane. This results in a field strength of 2 V/m
peak at the antenna. For more information about this, look at my postings
over the last couple of weeks on the thread "Antenna reception theory".

Roy Lewallen, W7EL

Not sure I really understand what is going on, but have been aware of your
previous postings, also on the NEC-list. What I should have said is that
the above program agrees with Reg's previous assumption -- but not with his
new program "grndwav4.exe". In any case, just to satisfy my curiosity, I
ran the following code, which is, in essence, almost identical to your
NEC-list post with 5.555.... kW input producing 1V/m peak at 1000m. The
following agrees exactly with Reg's new program.

CM Short Monopoles
CE
GW 1 50 0 0 1 0 0 0 0.000814
GW 2 50 1000 0 1 1000 0 0 0.000814
GS 0 0 1
GE 1
GN 1
EX 0 1 50 00 65698.12106 0.00000
LD 4 2 50 50 1.747 823.796
FR 0 3 0 0 19.9 0.1
RP 1 1 360 0000 0 0 1.00000 1.00000 1000
RP 0 181 1 1000 -90 45 1 1
EN

Noting the comments by others, obviously familiar with ATR measurement
techniques, this exercise with NEC is purely academic. There is no way you
could experimentally prove these results. Since I have never made
measurements on an "Open-air" test site it will be interesting to verify
Mac's assumptions, which I am sure are correct.

The confusions I have are now related to the fact that NEC results depend on
how the incident E-field is generated. I will check all previous posting by
Roy to see if I can figure out this anomaly. For some reason I have not
received any update concerning the NEC list postings.

Frank