[TowerTalk] 2"OD tubing inside a Rohn 25AG2

[K7LXC at aol.com]

In a message dated 5/2/2010 7:30:14 A.M. Pacific Daylight Time,  
towertalk-request at contesting.com writes:

>  I have 3 sections of 25G, the top being a 25AG2.  I  would like to use a
12' piece of 2" OD .25" wall 6061-T6 aluminum tubing to  get a total
height of around 40'.  The antenna will be a 2E  Steppir.  My question
concerns running the aluminum tubing through the  top of the 25AG2.  Is
this a reasonable application?   

Howdy --
 
    Sure. The OD of the top tube is 2.25" which  should take a 2" mast with 
no problem. 
 
    Island County is at least an 80 MPH windspeed  zone so the extended 
mast should be fine. 
 
>  Can I expect a lot of wear on the tubing when not using  a thrust 
bearing?  
 
    IMO thrust bearings are overrated. You  won't notice any wear worth 
worrying about. Sometimes the top tubes are welded  slightly off so the worst 
case is that there might be a little wear somewhere  on the mast but you'll 
never notice it. 
 
>  Will there be sufficient support for the tubing in the  rotator (a HAM 
IV)?




Sure. It'll take the  full weight with no problem. I'm assuming you're 
going to guy it - right?  GL!
 
Cheers,
Steve     K7LXC
TOWER TECH -
Professional tower services for hams