[TowerTalk] more on NVIS

[Bill Tippett]

W8JI:
 >As the antenna is lowered, efficiency takes a big hit and
signal levels at all angles decrease.

         Tom, when I decided to put up a high-angle
antenna to complement my 160 vertical, I modeled
a droopy dipole (or large included-angle inverted-V)
over average ground.  The optimum height for gain
at 90 degrees TOA was ~100' on 160, or a bit less than
1/4 wavelength.  As you lowered the antenna from that
height, gain dropped due to ground losses.  As you
raised the antenna above 1/4 wl, the high-angle lobe
began to squash as a new low angle lobe increased.

         Like a lot of stuff I see these days, someone
dreams up a fancy name (NVIS) for something that has
been around for eons (i.e. a cloud-warmer antenna).
I bet the Army paid some consulting firm megabucks
for dreaming up the name NVIS.  My favorite example is
ADD/ADHD for simple misbehavior.  Of course it takes
a PhD in Education to dream up those new terms!  ;-)
Little wonder our schools are dumbing down while we
spend their resources for such nonsense.

                                 73,  Bill  W4ZV