hello;

until now I have used 4nec2 to model cubical quad type antennas. Now,
I have been asked to design an end-fire helical antenna with a
groundplane. I've figured out how to model a ground plane using 'fast
ground' and radials and stuff, but I'm having trouble with the
excitation. I guess I don't really know the particulars of it. When
I was designing cubical quads, I'd just slap it on the loop and be
done with it; I assumed that nec was sort of making an open circuit in
the loop and connecting a transmission line to it--that type of
thing. How do I tell nec that I want one end of the conductors
connected to the ground plane, and the other to the helix? Does it
know somehow?

Any more tips on modeling helical antennas with ground planes in
4nec2?

Thanks alot for your help;
Sean.