I am not saying the TB3 is a high quality product. But I have been using one
for 30 years on the same tower. The only change I made was to replace the
bolts with stainless steel. The mast is 2" and 32' long with 8' in the
tower. On the 24' sticking out of the tower I have had combinations of
antennas from initially a 105, 155, 205, 402 (the antennas sure flopped
around in high wind). Then a C31, MAG240N, Warc7, EF-606 combination. Now I
have a MonstIR.
And the 80' of Rohn 45 tilts over at the base. That puts a nice side load on
the TB3 with the antennas ganging down. Sure it makes noise if I turn it by
hand at a higher rate than 1RPM. Never had it apart. Seems to keep on doing
what it was designed for - keeping the mast centered and taking the load off
the rotator.
Maybe there are better thrust bearings. But will stay with my dry TB3 for a
while yet.
73,
N2TK, Tony
-----Original Message-----
From: towertalk-bounces@contesting.com
[mailto:towertalk-bounces@contesting.com] On Behalf Of Jim Thomson
Sent: Wednesday, May 19, 2010 10:00 AM
To: towertalk@contesting.com
Subject: [TowerTalk] thrust bearing lubrication
Date: Tue, 18 May 2010 11:56:14 EDT
From: K7LXC@aol.com
Subject: Re: [TowerTalk] thrust bearing lubrication
In a message dated 5/18/2010 8:39:28 A.M. Pacific Daylight Time,
Brahmangou@aol.com writes:
> Unlubricated bearings? Maybe the reason you are wearing out the races.
I use Moly grease on all of mine, no problems yet. Every bearing needs
lubrication, even old windmills from 100 years ago have oilers, and
windmills
only turn at about 75 rpm. Where I live dust and dirt above 50 feet is not
a
problem, maybe in West Texas or Arizona the big dust storms could deposit
enough to make a difference.
The Rohn thrust bearing isn't a conventional bearing in the sense
you're talking about above. It turns at 1 RPM. The manufacturer says does
not
say to grease it.
The LXC Prime Directive says to "DO what the manufacturer
says."
### it's a good thing I don't follow that rule. All my F-12 ants
would have fallen apart by now.. amps blown up, xcvr's that
are below par.. and require loads of mods etc, etc.
In this case, do not grease the Rohn TB.
## Ok.. so what does rohn suggest you do then.... replace the poorly
engineered TB3/4 every 6 x months ??
IMO... it's a way over priced piece of junk. Now, if you take it all apart,
remove the balls... smooth out the race.. lube both the raceS and the
balls.. and perhaps put a rain cover over the top of it....it will last a
lot longer.
If that set screw was replaced with a grease nipple fitting, we would not be
having
this conversation.
## use no grease in the wheel bearings on your car.. and poof, they won't
last
2 x days. It baffles me why manufacturer's keep making the same junk
year
in and out.... like TB-3/4's... W2AU baluns, BN-86 baluns, toy rotor's,
lousy
coax connectors you can't solder to, xcvr's with 15 % thd 1.5 watt audio
amps,
lousy headsets, yagi's that fall apart, yagis that have gross torque
imbalance,
rotor mast clamps that slip, and/or loosen.... muffler clamps with useless
sheet metal saddles, muffler clamps that rust. The list is a mile long.
## 'do what the manufacturer says' .... sometimes.... but only if they have
engineered the product correctly. A buddy just bought 190' of Rohn 55g.
None of the sections fit..and all of em..so far have had to be re-drilled.
Quality control has gone out the window.
Later..., Jim VE7RF
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