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Re: [TowerTalk] Tailtwister in Universal Top Section

To: Dennis W0JX <>
Subject: Re: [TowerTalk] Tailtwister in Universal Top Section
Date: Mon, 20 Feb 2012 15:50:59 -0500
List-post: <">>
Wait just a minute.

The top section simply puts SIDE support around the mast.  There is NO  
twisting of the top section by anything above it.  The ONLY twisting  
within that section occurs AT the rotor when the antenna stops  
turning.  Of course, if the rotor is HIGH in the section, that  
twisting will be transmitted into the top section.  However, it is  
recommended that the rotor be placed near the BOTTOM of the top  
section when it is installed.

I have never had a top section damaged in ANY way by the twisting  
action you describe, despite only one bolt per leg holding the section  
to that below it.
What is important is if the NEXT SECTION DOWN is ALSO 14" ... if so, I  
wouldn't put a rotor in the top section either!

To reiterate:  the rotor may be a tight fit within the 14" section,  
but will serve well as previously posted.


Quoting Dennis W0JX <>:

> Gary, it will be an extremely tight fit and I would advise against   
> it. I have had a Universal tower since 1977, first with a 60 footer,  
>  then 70 footer, and since 1998, an 80 footer. In all instances, I   
> used a long shaft to reach down to the 18 inch section where the   
> rotor is placed. The 14" top section is held in place with only one   
> bolt per leg and if you put the rotor there, you might have too much  
>  twisting action (depending on the size of the beam) and the top   
> section will break. The longer mast absorbs some of the twisting   
> action.
> Currently, I am turning my TH-11 (12+ sq feet of windload) with a  
> 1977 Tailtwister which has never been opened up. It is a very  
> capable rotor. I have a thrust bearing in the middle of the top 14"  
> section but the rotor is halfway down the second 18 inch tower  
> section.  
> 73, Dennis W0JX/8
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