[TowerTalk] TB3 Thrust Bearing

Bruce Ferratt uglyatc at msn.com
Wed Mar 15 15:58:02 EST 2006

I purchased the TB-3 because the Yaesu GM-050 bearing didn't mount on to the 
Rohn AS25G plate. It wasn't even close! Believe it or not I think I might be 
overkilling the entire project.  This is a 60ft tower, bracketed to my house 
at 20'.  I will be guying it.  I used 52 bags of 60lbs concrete at 4ft deep 
X  28" X 28".
The bracket is installed through the siding with carriage bolts and secured 
inside a room with a pressurized 2 X 6 board.  The bracket is bolted into a 
footing and the other three carriage bolts for the bracket go between 3 
studs inside the room.  I don't think it is going anywhere once it is guyed.
The tower has the 9ft top section with the peak.  Will be using an aluminum 
mast 1 1/4" OD with Yaesu G-450A rotor.  Beam is a Mosely TA-33M and stacked 
2m/440 vertical.

Any recommendations would be great but the concrete is already poured and 
bracket is installed.  Am waiting for better weather to start stacking tower 


>From: Jon Zaimes AA1K <jz73 at verizon.net>
>To: uglyatc at msn.com
>Subject: re:  [TowerTalk] TB3 Thrust Bearing
>Date: Wed, 15 Mar 2006 11:15:40 -0500
>If the original bolts are not long enough to tighten down on a 1 1/4 inch 
>mast, you could replace them with longer bolts that would do so.
>But the TB-3 is a bit of overkill for that small a mast. A 2 x 4 block of 
>treated wood drilled slightly larger than the mast would be sufficient. In 
>fact Rohn used to sell such a block of wood (I think it was oak or cedar 
>rather than treated) with a hole for a 2-inch mast.
>73/Jon AA1K

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