The 20 foot sections that are smaller/placed at the top have solid
rod legs/solid rod cross braces and are annotated 5N to 1N
(smallest). Sections 6N and larger have "angle iron" cross braces
with galvanized tube (hollow core) legs. For a typical amateur radio
application (20 sq foot wind load??), a 100 foot tower would have no
section smaller than a 3N at the top (3N to 7N). Using a rotator
will require custom fabrication of at least two platforms (one for
the rotator and one for the thrust bearing). I have a second thrust
bearing in my set-up using just angle iron and muffler clamps since
it is only for use when I have to remove the rotator for repair (if
needed). In a correct SSV self supporting tower set-up, the beam(s)
will go long before the tower 'breaks a sweat'. I have a 3-element
40 meter beam that Hurricane Ike did in rather quickly without any
impact on the tower at all. Same thing happened to my 40M - 10M log
periodic back in the 80's. Of course this is for reasonable antenna
wind loads. Ken K5RG
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