[TowerTalk] Water pipe

[Lee Buller]

At 08:46 AM 11/11/97 +200, you wrote:
>K5GO wrote:
>> If I am stacking antennas such as my little Cushcraft 2 Element 40 which
>> is about 10-12 Ft above a 4 Element 20, I'll telescope a Schedule 40
>> 1.00" galvanized water pipe inside the 1.5" one and drill and pin them
>> near the top with  1/2 inch bolt.  
>
>That's EXACTLY what I did with my 402BA (2 el Shorty Forty) above a 
>205BA (5 el 20 short boom) for several years, without a problem.  I 
>moved the same tower to the new station, this time with a C3 
>tribander below the 40.  Within six months, a storm had bent the mast 
>about 30 degrees, just where it leaves the thrust bearing.  It was a 
>bitch to fix!
>
>Bottom line:  On my new tower I went for the real stuff.
>
>Chris R. Burger
>ZS6EZ

The issue I have with this senario is drilling the mast.  I have done this
in the past, but if I had my druthers, I would never...never...never pin a
mast if I could help it.  I don't care how tight you drill the hole, or how
hard the bolts are...the wind moving the beam around will wallow out the
holes and the whole thing will get loosy goosy.  Once you get a degree of
arc (slop) in the mast, you will take out your very expensive rotor.  Just a
warning...cause it has happened to me.

Lee
k0wa@southwind.net


--
FAQ on WWW:               http://www.contesting.com/towertalkfaq.html
Submissions:              towertalk@contesting.com
Administrative requests:  towertalk-REQUEST@contesting.com
Problems:                 owner-towertalk@contesting.com
Search:                   http://www.contesting.com/km9p/search