For gary and oall.

NVIS is near vertical incidence and I forget the "s".

Anyway, the simplest antenna for this work is a very low dipole or loop.
There have been several articles in the past few years of qst on the 
subject.

For my first experiment, I would just string a 75 or 40 meter dipole, 
whichever band you desire  at less than 1/8 wavelength high and play.

I'll do some more looking tomorrow when I'm more awayke; but that will get 
you started.