[TowerTalk] C31XR and Prosistel ring rotator

[Tom_N2SR via TowerTalk]

Not sure if I am the first one to have this combination, but I figured I would ask the group for help. 


I have a Force 12 C31XR mounted on a Prosistel ring rotator at 80 feet.  Before we got the antenna up, 

we decided to remove the elements (1st director on 10, and 1st director on 15) where the antenna would
normally be attached to a mast.  

The Prosistel ring has a1/4" plate that attaches to the ring itself.  There is no cradle like the tic-general rings.

The Force 12 elements are insulated and are mounted below the boom.  I have not done the actual measuring, 

but it appears that the outer diameter of the ring is larger than the space between the two elements.  By how 

much, I do not know, but it might only be an inch or so.  Best case is that I am incorrect about the 

measurements.  Not a good case is that the elements will go on, but they one might be touching the ring. 

I could probably add insulators to one side of the element and keep the element from touching the ring.  

Worst case is that the elements will not fit.  


If that is the case, I have three options.  


I could make blocks and raise the antenna boom off the plate enough to have the elements clear the ring. 
Tough to do by myself.  


I could move one or both of the elements slightly. That would be moving the 1st director on 10 a bit closer 

to the 10M DE and moving the 1st director on 15 slightly away from the 15M DE.  


I could move one or both of the elements to the top of the boom.  If I did that, would that cause any problems 

with respect to gain, F/B, matching, etc?  

The second and third option would involve drilling out the rivets, which while not the best thing to try at 80 feet, 

isn't impossible.  


IF I have to do one of the three, which would you do?  

I bought the C31XR's because I knew they had enough space to rotate around Rohn 45.  I never thought to 

think about the actual outside diameter of the ring and how close the elements might be.  


Thanks for the input. 


Tom, N2SR