Rick wrote:
On Mon, 09 Apr 2007 23:36:56 +0000, Dave Oldridge wrote:

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.

Right. That's my point. So, what I'm claiming ... and trying to get
someone who knows more about this stuff than I do (which is just about all
of you) to confirm or deny ... is that with an NVIS dipole, someone 100
miles away from me would not be able to perceive the difference if my
antenna was broadside to him or oriented in line with him. True, or false?

Most likely TRUE. Other conditions may affect the signal but for the
most part the signal goes almost straight up in all directions and
almost straight down in all directions. Your coverage can be up to 300
to 500 miles depending on conditions. The MUF for NVIS is dependent on
the position of the sun and drops drastically at and after sun set.

Dave WD9BDZ