NEC2 versus NEC4WIN models

Time for my dumb question of the day. I've included two models of the
same design -- one for NEC4WIN95 which has the pattern I want, and
what should be the same in NEC2. Unfortunately the NEC2 one comes out
completely different -- it appears to be symmetrical.

And I can't work out why. I'm using 'xnecview' to visualise the
patterns, and using the example RP card from the xnecview manual. The
RP card seems quite thorough and changing the values doesn't help.

The NEC4WIN95 model says 10 segments per wire and the NEC2 model says
11; I had to change it to 11 to get the feed point in the middle of
one of the wires. NEC4WIN95 seems to divide the wires slightly
differently.

So here's the NEC2 model:

CM
CM NEC4WIN95 File
CM VK3SB 6m quad -- auto generated
CE
GW 1 11 0.000 -30.600 30.600 0.000 30.600 30.600 0.1000
GW 2 11 0.000 -30.600 -30.600 0.000 30.600 -30.600 0.1000
GW 3 11 0.000 -30.600 -30.600 0.000 -30.600 30.600 0.1000
GW 4 11 0.000 30.600 -30.600 0.000 30.600 30.600 0.1000
GW 5 11 -54.348 -31.785 31.785 -54.348 31.785 31.785 0.1000
GW 6 11 -54.348 -31.785 -31.785 -54.348 31.785 -31.785 0.1000
GW 7 11 -54.348 -31.785 -31.785 -54.348 -31.785 31.785 0.1000
GW 8 11 -54.348 31.785 -31.785 -54.348 31.785 31.785 0.1000
GW 9 11 17.616 -28.763 28.763 17.616 28.763 28.763 0.1000
GW 10 11 17.616 -28.763 -28.763 17.616 28.763 -28.763 0.1000
GW 11 11 17.616 -28.763 -28.763 17.616 -28.763 28.763 0.1000
GW 12 11 17.616 28.763 -28.763 17.616 28.763 28.763 0.1000
GS 0 0 0.254
GE 0
EX 0 2 6 0 100.0 0.0
FR 0 0 0 0 50.13
RP 0 37 72 1000 0 0 5 5
EN

and the NEC4WIN95 model:

CM
CM NEC4WIN95 File
CM VK3SB 6m quad -- auto generated
CE
GND Reference
UNITS Inches
Height 236.220
Over Perfect Ground
Boundary Circular
F 50.130
GW 1 10 0.000 -30.600 30.600 0.000 30.600 30.600 0.1000
GW 2 10 0.000 -30.600 -30.600 0.000 30.600 -30.600 0.1000
GW 3 10 0.000 -30.600 -30.600 0.000 -30.600 30.600 0.1000
GW 4 10 0.000 30.600 -30.600 0.000 30.600 30.600 0.1000
GW 5 10 -54.348 -31.785 31.785 -54.348 31.785 31.785 0.1000
GW 6 10 -54.348 -31.785 -31.785 -54.348 31.785 -31.785 0.1000
GW 7 10 -54.348 -31.785 -31.785 -54.348 -31.785 31.785 0.1000
GW 8 10 -54.348 31.785 -31.785 -54.348 31.785 31.785 0.1000
GW 9 10 17.616 -28.763 28.763 17.616 28.763 28.763 0.1000
GW 10 10 17.616 -28.763 -28.763 17.616 28.763 -28.763 0.1000
GW 11 10 17.616 -28.763 -28.763 17.616 -28.763 28.763 0.1000
GW 12 10 17.616 28.763 -28.763 17.616 28.763 28.763 0.1000
S 1 14 100 0
Coax 50

I tried putting the NEC4WIN95 model at a large height to emulate free
space and it still didn't come out anything like the NEC2 one. So can
anyone see the flaw before I pull all of my hair out?

thanks,

Hamish (frustrated!)
Received on Mon Feb 28 2000 - 15:02:20 EST