Rick wrote in newsan.2007.04.09.16.49.43.321645
@reply.in.gp:


My experience seems to be that the performance of NVIS dipoles (at or
under around 30 feet high for 80 meters) doesn't noticeably change with
orientation. In other words ... and despite what modeling programs say
... BVIS dipoles are pretty much omnidirectional.

NVIS propagation is pretty high angle stuff. If you look at the three
dimensional patterns for NVIS antennas you will see that they have a large
lobe at high angles and an almost circular omnidirectional pattern at those
angles. We're looking at 80 degrees and up mostly here, maybe 70 at the
low end....so that antennas are mainly designed to illuminate the patch of
ionosphere directly above the antenna.

--
Dave Oldridge+
ICQ 1800667