On 21 Sep 2006 19:09:38 -0700, "art" wrote:

Notwithstanding that the
upper half of the major lobe serves no usefull purpose to what the
antenna is required for there is a mass of radiation in many directions
and levels that have no connection to the required purpose of the
antenna, thus we have a lot of wasted radiation that if we harness it
so that it is used for the antennas primary use the efficiency of the
antenna would increase immensly.

Hi Art,

The classic solution is to stack yagis vertically. This draws down
the higher radiation lobes and puts their gain in the forward
direction.

However, unless you can positively insure that higher radiation does
not actually find its way to the target (you need a propagation
modeler to prove that, by the way), then you could be muffling
yourself at one elevation to yell at another elevation that is only
heard in points remote from the target.

In other words, if you suppress the lobe at 20 degrees to optimize the
lobe at 10 degrees, you may miss your target altogether. Given that
skip works on so many variables, an "efficient" antenna may be wholly
useless.

73's
Richard Clark, KB7QHC