[TowerTalk] [SteppIR] boom balance

[Al Williams]

How important is it to balance the load on a rotator and which rotator is best able to withstand a completely one sided load?

I have a bracket/platform under construction that will bolt to the second section of a 70' crankup tower (which puts the platform at about 35'.
The rotator will be mounted on the platform at about 15 inches from the face of the tower.  The mast-to-boom plate will hold the boom at the end of the boom (making the completely one sided load).  The boom will be a modified 2 el Steppir boom that places the reflector about 12 inches
from the rotator center making the boom into a swing-away arm?  This will allow the Steppir to rotate over 180 degrees before the reflector bumps into the tower legs.  The capability of the Steppir to reverse direction will be used to obtain the other 180 degrees.  The purpose of this design is to avoid interference between the 2 el Steppir elements and the leads coming down from the upper antenna as the leads will be on the opposite side of the tower from the 2 el Steppir.

This design will result in an unbalanced load on the rotator of about 15 ft-lb from the reflector and about 75 ft-lb from the director and boom.

I will appreciate opinions on what the damage to the rotator may be and which rotator(s) would be able to withstand the unbalanced load. 

k7puc

---- Original Message ----- 
  From: Mark Klocksin 



  I just installed a Ham IV rotor to turn my 3-element SteppIR.

  Somewhere in the rotor information I read that the load should be  
  balanced.73,

  Mark WA9IVH