[TowerTalk] Mast slipping

Byron Lichtenwalner w3wkr at verizon.net
Fri Apr 20 21:27:01 EDT 2007


I am in the process of replacing my current rotor with a 2800.  I have a
Steppir MonstIR on a 2" mast.  
In the attached note Steve suggests pinning the 2800 mast clamps for
everything EXCEPT the antenna I have.
 
What would you suggest for the MonstIR ?
 
Byron, W3WKR
 
In a message dated 4/17/2007 7:24:54 P.M. Pacific Daylight Time,  
cmsande at gmail.com writes:
 
>  I saw some old posts by you (circa 2002) stating that you have  started 
pinning the Orion rotators due to slippage.  I have a Orion  RC2800PX
turning a 
4L SteppIR and each time we have some wind, by antenna gets  swung out of 
position.  This happened again today. 
 
Hiya, Craig --
 
    It's an Orion design flaw, the mast clamp has 2  problems. First, the 
surface where the nuts and bolts seat are dimpled - not  flat. Over time,
the 
wind motion causes the washers to pound the dimples flat,  thus loosening up

the 
nuts; then the mast is loose and starts moving. The  problem can be
eliminated 
by milling or grinding those surfaces flat. 
 
    Secondly only 2-3 teeth of the clamp actually  contact the mast, 
resulting in very little clamping. Then you get the teeth  being worn down
as 
the mast 
moves back and forth and it loosens some more.  
 
You can re-tighten everything and it'll probably  be good for a couple of 
years. For a 4L SteppIR, you can also pin the mast.  Pinning works for 
everything 
except a MonstIR. 
 
 
>  I have heard good things about the Green Heron Engineering  univeral 
rotator controller, which can be re-calibrated in case the mast slips  in
the 
rotator, however eventually the coaxial cable loop would start wrapping
around 
the 
mast if I did nothing more to secure the rotator-to-mast  connection. 
 
    The GH controller is very nice but won't do  anything about the basic 
problem. 
 
 
    What I do for my customers is provide a new  replacement mast clamp that

uses 6 U-bolts to hold the mast and does NOT slip.  It's $120.00 but if you 
re-tighten everything and pin the mast, you'll be good  to go. 
 
Cheers,
Steve      K7LXC
Champion Radio Products
Cell: 206-890-4188
 
 

 



More information about the TowerTalk mailing list