[TowerTalk] Removing a Rotator

[K7LXC at aol.com]

In a message dated 6/18/2008 10:36:36 A.M. Pacific Daylight Time,  
wc1m at msn.com writes:

>> You need to jack up the mast just far enough to remove   the rotator and
>> you'll be good to go.

>  OK, that  brings up something about which I've been curious: exactly how do
you jack  up the mast? Someday I'll have to do that to get my Orion rotor out
for  service, and I can't quite picture the process.

>  I'm assuming  you attach a come-along cable to the mast and hook the
come-along on a  tower rung. But where and how do you attach them?


    Well, one end goes as near the top of the tower  (rung or nylon sling) 
and the other end attaches to the mast with a nylon  sling. I use nylon sling 
chokers to grab masts and other odd shaped items.  

>  I have two thrust bearings, one in the top plate and one in  a plate 
between
the top plate and rotor shelf. There's about 5 feet of mast  in the tower,
with about 3.5 feet of it above the middle thrust bearing  plate. The
come-along cable would have to be attached between the top and  middle thrust
bearing plates. That doesn't leave a lot of room to attach  the come-along to
the tower above the point of attachment.
 
    You're right. It'll still work okay - you're not  trying to lift the mast 
very far. An inch or two is all  you need to do a  rotor swap. 

>  Seems to me a better idea is to run the cable  up from the mast to a pulley
attached to a rung, and from there down to the  come-along. The higher the
cable can run before encountering the pulley the  better. Otherwise, the
cable will be pulling sideways more than up.
 
    I'm not sure how your scheme relieves the slight  sideways pull but it 
sounds okay. It's a good idea if you don't have much room  at the top of the 
tower plus it gives you some additional mechanical  advantage. 

>  It's not a problem in my installation, but if  you had a heavy mast with a
lot of antennas, wouldn't attaching the  come-along and pulley to a rung risk
bending a rung? Would it be better to  u-bolt a piece of angle steel between
the legs and hang the come-along from  that?
 

I use nylon slings and carabiners for just  about everything so I wouldn't 
use a fabricated piece of steel. It's more  weight to deal with plus you have to 
fabricate it. 

 
Cheers,
Steve     K7LXC
TOWER TECH -
Professional tower services for hams

 



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