[TowerTalk] Rohn SSV Towers

[Kenneth R. Goodwin, Jr.]

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