[TowerTalk] Trust Bearings

[WD0M]

I used one in Alaska, with temperatures of - 40 F, 125 mph wind gusts, and 
all the typical worst case weather you can imagine (well, OK, it only got 
up to 72 degrees F in the summer), and the thrust bearing that worked great 
for me was by Glenn Martin Engineering.  In fact, when I moved from Alaska 
to Colorado recently, I removed it from the Hazer, and it now resplendently 
resides atop my USTowers TX-455.  It had to be custom mounted on the tower 
here, but it has 6 stabilizing bolts that screw into the mast, giving great 
support.  The mast is only about 4 feet inside the tower, and almost 10 
feet above it, with the 4 element SteppIR antenna residing about 5 feet 
above the top of the thrust bearing.  The added mast above the antenna is 
there to provide support for the Phillystran cables that help keep the 
SteppIR nice and level.

http://www.glenmartin.com/Hazer/pg4.htm

73,
Joe
WD0M
(ex-WL7M)

At 05:01 PM 12/29/2003, Noel wrote:
>I'm trying to decide what type of thrust bearing to use at the top of a
>60' tower to support a small quad.  The antenna only weighs 35 Lbs but I
>want the boom as high above the tower as possible to keep the elements
>above the guy wires and get about half the antenna above the tower
>rather than around it.  So I'm thinking of using a 12ft mast with about
>6 ft of mast inside the tower and a thrust bearing at the top for
>stability and keep some pressure off the rotator.
>
>I'm Looking for suggestions on what type/make trust bearing works well
>and will hold up in icy winter conditions as well as the heat of summer.
>
>Appreciate any recommendations.
>
>Noel,