my stacks are all monobanders.
on 40m its 4-ele's at 180' & 100'
on 20m i have 4-ele's at 150/120/90/60'
on 15m and 10m its 4-ele's at 120/90/60/30'
on 20m, 15m, and 10m there is another 4 ele fixed south.
also on 20m, 15m, and 10m, the middle 2 are fixed at europe and selected
together, and the bottom ones are on ring rotors and separately rotatable
from the top one.

so on 20m, 15m, and 10m, i can select the top along, the middle two at
europe together, the bottom one alone, or the south one alone. And then i
can also select the top, middle, and bottom all together, and the top,
south, and bottom all together to spread the signal out when the bands are
open in more than one direction.


"art" wrote in message
oups.com...
David, are you saying that your three-some stack is made out of tri
banders of the same design such that a lobe null can be filled? I
believe that is exactly the coverage the poster is looking for, he
wants to be around to hear when the tree falls
Art

Dave wrote:
"Cecil Moore" wrote in message
t...
CW wrote:
I've been wondering for some time now why amateur operators don't
build
their Yagi antenna's
so they can be raised and lowered about 10ft in addition to being
rotated.

Many do, using motor driven towers. In addition to lowering
their arrays when a storm hits, some raise and lower their
towers during marginal conditions to maximize signal strength.
--

its really only practical on crank up type towers, for those with guyed
towers its usually not possible.

10' change on 20m would likely not be very useful though. my hf stacks
for
10/15/20 are all spaced 30' apart, 40m is spaced about 80'. even with
those
height changes (which i can select instantly so i can make direct
comparisons without worrying about fading) there is often little
difference
between antennas... though sometims there is a lot of difference. This
highlights the fact that often the signals arrive with a wide range of
angles, though at some times they must be in a relatively narrow range.
so
having multiple antennas at different heights that can be selected in
various combinations is a handy thing to do.