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Old May 9th 06, 04:31 AM posted to rec.radio.amateur.antenna
Frank
 
Posts: n/a
Default question: NEC2 w/ ground parms.


"rjtucke" wrote in message
ups.com...
Per emailed request, here is my deck:
CM 40/15M folded dipole model by NS7F
CE
GW 1 11 -10.2761 0.0508 10.0000 10.2761 0.0508 10.0000
0.0016

..
..
..
GN 2 0 0 0 12.0000 -0.007
RP 0 35 71 1001 0.0000 0.0000 5.0000 5.0000
EN


My first observation is that your soil conductivity is zero.
Should always be zero (GN card should be: GN 2 0 0 0 12.0000
0.007).
I am certain that this would give you the kind of error messages
you are seeing. The program actually runs under these conditions, using
Nittany's NEC-Win Pro,
but produces erroneous results -- input impedance, radiation patterns etc.

Correcting the conductivity gives much more realistic results: resonant at
6.8 MHz,
Zin 700 ohms, classic dipole pattern.

Your segmentation is probably a bit low for such close proximity conductors,
also
the segment sequence could be improved, but not important unless you want to
graph the conductor currents. I would suggest making the conductor segments
equal to the triangle side lengths. This may change the results a little,
but the
correct sign for conductivity will make a big difference.

Regards,

Frank