On 3/25/2020 14:37, Randy via TowerTalk wrote:
I’m in the process of putting up a Rohn 25G tower.The top section is a
25AG4 which is a flat top section and of course a thrust bearing on
top.In Michigan I had a US Tower TX-455 and a Heights tower which I
sold before moving back to Florida last year.One had the HAM IV and
the other had the T2X Tailtwister.Plenty of room in either tower for
either of these two rotors.But it’s a different story with a Rohn
25G.The only spot where a Ham IV or T2X will fit in a Rohn 25G is an
area about 2 feet below the top flat plate where there is no diagonal
brace.That would leave only about 12” of mast above the rotor before
the thrust bearing.In the past I’ve always tried to put the rotor
further down into the tower.
I have read online that some folks will cut the brace out in order to
get a Ham IV or a T2X in the middle of a section.Not sure if I like
that approach.Maybe a different rotor besides a Ham IV or a T2X.
Any suggestions would be appreciated.
I've had a T2X in that location of a 25AG4 for over 30 years, and never
had a problem. I have a big tribander 2 feet above the thrust bearing
(Formerly TH7, now JK Mid-Tri), and a D40 rotatable dipole 8-10 feet
above the bearing. After 29.5 years, the bearing races in the original
rotator were pretty beat up, but it still worked. This is in WI, where
we get some pretty bad storms sometimes.
73,
Scott K9MA
--
Scott K9MA
k9ma@sdellington.us
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