In my experience, there are two things that can cause rough
operation of a TB3
other than roughness in the races. When you get the TB3 in
your hand, notice
the set screw inside the TB3 that allows you to remove the
bearings. On early
TB3's, those over about 4 years old, there was no means to
keep that set screw
in the optimum position in its hole. It was not tight
against anything and
free to creep in or out to a limited degree. It could not
come all the way out
because it would hit the mast, but it CAN come out far
enough to create a hole
where the bearings are such that a bearing can get caught in
the hole. I have
actually seen TB3's jam tight when this happens. Or,
conversely, that set
screw can creep in toward the bearings to a point that it
pinches one of them
in the race and that also causes the bearing to hang up.
My solution to this problem was to drill and tap a small
hole up from the
underside of the bearing right below the bearing set screw.
Then I would
install a smaller set screw in that hole to hold the first
set screw firmly in
place at the correct depth so neither of the above problems
could occur. I
suggested this to Rohn as a TB3 modification but, as usual,
I never got any
acknowlegement about it from them. Rather, they implented
their own version of
the solution by simply peening the side of the bearing set
screw hole to try to
prevent it from moving. Not a very elegant solution in my
opinion, but
certainly a cheap and easy one . . . The TB3's I have been
receiving from Rohn
for the past 4 years or so have peened set screw holes and I
guess that solves
that problem . . .
Stan
w7ni@easystreet.com
Sylvan Katz wrote:
> TT's
>
> I just took the TB3 thrust bearing off the top of my 25G foldover.
> Throughout the winter it seemed as if the bearing was binding and sure
> enough when I took it off the tower I can see that it is not rotating
> freely. Perhaps there is some dirt in the race. Does anyone have any
> pointers about cleaning a TB3?
>
> tnx
> .. sylvan
>
> ----------------
> Sylvan Katz
> VE5ZX & G0TZX
> Saskatoon, SK
>
> List Sponsor: Champion Radio Products - We'll be at the Dayton Hamvention
> with all of our safety equipment and other products. Stop by booth #559 and
> say hi.
> <A HREF="http://www.championradio.com";>www.ChampionRadio.com</A>
>
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List Sponsor: Champion Radio Products - We'll be at the Dayton Hamvention
with all of our safety equipment and other products. Stop by booth #559 and
say hi.
<A HREF="http://www.championradio.com";>www.ChampionRadio.com</A>
-----
FAQ on WWW: http://www.contesting.com/FAQ/towertalk
Submissions: towertalk@contesting.com
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Problems: owner-towertalk@contesting.com
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