> This is all quite fascinating. If you are designing an
> antenna installation for hams (or, if as I am doing, you are
> looking at optimizing phased arrays for hams), the ionospheric
> effects might actually be less important than such things as the
> antenna configuration on the other end of the (speculative) link
> and the relative times of day, and, in the contesting scenario,
> what all the other hams are doing.
As I recall, the N6BV path data is a compilation of all angles
over the entire solar cycle and were generated with isotropic
radiation (with gain) on both ends. Those angles with higher
probability occur more often or last longer.
The idea then, is to create an antenna system with either a
big fat vertical lobe that covers ALL the desired angles or
one with a more narrow, slewable, take off angle that can be
adjusted to cover the entire range (e.g., a stack of yagis with
selectable phasing and height).
The problem of an antenna with too low a take-off angle is not
as rare as one might think. It shows itself every time a
station with a big yagi on a very tall tower gets beat by
the guy down the street with a low tribander in the pile-up for
a Dxpedition running a yagi at 20 or 30 feet
... Joe, K4IK
See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless Weather
Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any questions
and ask for Sherman, W2FLA.
TowerTalk mailing list