NEC-LIST: Inverted-V and NEC

Hi,

I am trying to simulate an inverted-Vee in a NEC variant called NecWin+.

I generate 2 wires (legs) that almost touch each other (for instance
separation of 0.1). Each leg has X segments and a length equal to lambda/4.
A third wire is generated that connects both legs and holds the default
voltage source.

In order to run the simulation, I have to make sure that X > 11 (number of
segments of antenna legs) otherwise the compiler generates the error "No
segment has an ITAG of 1". Based on the rule of thumb, 11 is on the high
side, moreover, the wizard would generete something around 4 segments for
each leg but again this wouldn't compile. Also, when I look at the current
distribution, it is not symmetric over the two legs. One leg is almost dead
compared to the other. The results are not even close to what is expected
and changes dramatically with increasing X (the number of segments).

I would appreciate it if somebody could help me out with the simulation of
an inverted-Vee. I know that it is not a state of the art antenna but
because of the problems I had while simulating, it became quit interesting
to me. I would like to understand why it does not work with #segments
smaller then X=11 and why there is no symmetry in the current distribution.
For those that would like to have more detail, I attached the NEC Code of an
Inverted V @ 14.2 MHz, 60 feet above the ground and an angle of 90deg
between the legs. The separation is 0.1.

Thanks,
Filip Weytjens

CM
CE
GW 1 11 -12.27 0 47.78 -0.05 0 60 0.0053545
GW 2 1 -0.05 0 60 0.05 0 60 0.0053545
GW 3 11 0.05 0 60 12.27 0 47.78 0.0053545
GS 0 0 .30479
GE 1
GN 1
EX 0 2 1 0 1 0
LD 5 1 1 11 5.8001E7
LD 5 2 1 1 5.8001E7
LD 5 3 1 11 5.8001E7
NT 1 11 2 1 0 0 0 0 0 0
FR 0 11 0 0 14 0.1
RP 0 1 360 1000 90 1 1 1
FR 0 11 0 0 14 0.1
RP 0 1 360 1000 89 1 1 1
EN

-- 
The NEC-List mailing list <nec-list_at_gweep.ca>
http://www.gweep.ca/mailman/listinfo.cgi/nec-list