Date: Sat, 18 Feb 2017 17:57:09 +0000 (UTC)
From: DAVE WRIGHT <kanives@yahoo.com>
To: "TowerTalk@contesting.com" <TowerTalk@contesting.com>
Subject: [TowerTalk] T2X Multiple failures, fix?
?Greetings all,
I've been having a continuous problemw/my tower setup since installed in 1993'.
I just can't figure it out. I've mentioned this online in the past, & received
much helpf/hams/clubs & groups (K6EAG/TT/& NCCC) both local & abroad,thank you!
However the system is still having the same problem; itseems incurable. :(
The system is: Tri-Ex LM-354 tower (54'HD crank-up, w/tilt-over base), that
keeps eating rotors. The Yagi isa Mosley ?Pro-57b,? mounted on various mast
lengths/strengths(both short & long), 2? OD/1/4" ID f/aluminum. Have also tried
differingmaterials (both steel & thick-wall aluminum), w/a thrust bearing(used
3 in 23 years/both stainless-steel sealed bearings, &?open? bearings using
marine grease (local salt-air/SF, CAbay-side.) I've been using T2X rotors
mounted IN tower f/the start; & they eitherdon't last long, or quit immediately
(last 2), ?right after? arebuild.
Originally purchased the 1strotor new, & have had the last 2 rebuilt/exchanged
several timesvia the two popular repair/rebuild shops here in the US. The
onlypossible problem I can see from the ground is the Yagi ?swings? abit back &
forth after done turning/brake initialization. (looks like the swing is too
much?)
Other than that, nothing seen exceptwhen it starts to fail, it will not turn up
on tower; even though itturns fine on the ground. That is, until it becomes
?stuck? forgood/then I send it off f/a rebuild. The repairs typically
mention?brake failure.? I have since purchased the ?brake-delay?PCB, & the next
rotor will have it installed in box.
At this point I'm -almost- positiveit's an ?alignment? issue(?), but I'm not
clear how proceed. Ihad assumed perhaps wrongly that once everything was bolted
together,it's functional/should work. I have now been advised that
assumptionmight be incorrect. If someone could point me to a link/site
w/theironclad alignment procedure in writing/illustration/or video, thatwould
be perfect.
When functional, the system worksgreat! =304 worked/277 confirmed. Most w/this
system, & a fewwires/dipoles/ smaller Yagi's prior to this large Yagi. Problem
is,it's been down more than 60% since installation. Never had theseproblems w/a
small tri-bander; this just sucks! :( I'veabout given up; & haven't been on
much at all. (99% HF.)
This record of failure is justintolerable, & now that my age is getting up
there w/healthissues, I won't be able to work on it much. Need help as itis.
Any suggestions/troubleshooting discussion? I would be reallyhappy to get on
air & try f/the last few ?rare ones,? &do a few more of the popular contests
before kicking da bucket. :)
Thank you all,
Dave K6JOX 73
## A pro-57, by itself is not a huge antenna. The T2X should not be an
issue. How many thrust bearings are you using ? How far into the tower is the
rotor ? After reading the above, and with multiple failures, it may well be an
alignment issue. The top bearing might be a tiny bit out compared to the main
axis of the T2X, causing it to partially bind at some point in its rotation.
IF a 2nd thrust bearing is used, the chances of getting the rotor , + 2 x
bearings all in precise alignment is difficult at best. IF a 2nd bearing is
used, like just above the rotor, its set screws should not be tightened down.
Any 2nd bearing is just there to stop the mast from deflecting inside the
tower in high winds. Is the very top plate and rotor plate parallel to each
other ? Is there a locking collar on the very top plate ? UST uses a locking
style collar, welded between the very top plate, and a 2nd welded plate, just
a few inches below. Its used to lock the mast in place,
IF the rotor is removed.
## When your rotor is removed for repair, how are you supporting the bottom
end of the mast ? If its just flopping about, it could put a slight wow, or
bend in the mast itself, causing more binding when the replacement rotor gets
installed.
Jim VE7RF
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