At the risk of sounding glib or like a F12 fanatic (which I am, but not for
any financial or commercial reason), this is a no-brainer to me:
C-51XR @ 120'
Some 80 meter antenna @ 101' - probably a Magnum 280C, or if money or
loading is an issue, an EF-180B
C-31XR @ 90'
C-51XR @ 60'
C-31XR @ 30'
Rotate the mast with some largish rotator (is a Tailtwister big enough?),
and put the lower three antennas all on ring rotors.
Feeding and radio connection is left as an exercise for the reader, but be
sure that you can stack the two '51's on 40 meters while using the 90' '31
on a second radio for 20 meters.
Pricey - but deadly effective.
Just one man's opinion - and to be honest I have absolutely no real world
experience with systems anything like this.
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