Gary
Regarding tower height
No big deal between 70ish and 80ish feet...
I found that the difference between 20m at 95' vs 35' and or 15m at 95' vs
45' were that higher was sometimes better and then the lower was sometimes
better. If it really matters (eg your are trying to win a contest) - you need
both and then another 30 or 40 or 50 feet on top of that. Otherwise, take the
easy route.
Guying...
OK - I was on a hilltop with a 700' face that always had hefty venturi
wind... It ate every rotator or antenna I put up, so I am probably biased to
conservatism. To me, 2 sets of guys for a 70 or 80 foot tower with that much
antenna sound like trouble. Mine was 90 feet with 3 1/4" EHS guys - based out
at 80
feet. Top load was various. Generally it wa the 20 or 40 meter ants
mentioned below or a 4el 15M Cushcraft in place of the 40. No problems - even
when a
60' oak tree let loose and landed on the guys.
Regarding seperation:
I ran a 3 element 40M Mosley (a beast) about 5 feet below a 3 el 20 meter
Telrex.
If setting USA single band records in ARRL (40) and CQWW (20) CW are any
indication, 5 feet definately worked for me.
As far as how much mast above the tower...
That Optibeam also sounds like a beast... To me, trying to run 18 feet of the
mast above the tower does not sounds like a good idea. I AM assuming that
antenna goes on AFTER mast and rotator and top antenna are in place. Keep in
mind - if you eat your rotator (I have killed EVERY top end rotator made aside
from Telrex and prop pitch) you will have a hump of a job to deal with.
de Bill - K2EK
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