[TowerTalk] Lift Mast to Replace Rotator

[Keith Hanson]

I have had a fair amount of experience swapping rotators.  At one point Hygain/MFJ had a pot problem; mine were wearing out in roughly a year.  What I did was procure a 2nd "hot swap" rotator so that I could do a replacement in a single tower climb.

I place my masts about 1/4" above the rotator bell so that when it is time to swap all I need to do is remove the bottom and clamp bolts and tip the HamIV out.  The new one is tipped into place, bolts connected and I am ready to go in  about an hour.

The key is to clamp the mast at the thrust bearing ( I used a muffler clamp) so that the weight of the mast and antennas is held off the rotator.  Once the new rotator is in place and clamped to the mast (with the 1/4" clearance) I loosen a set screw in the thrust bearing so that full weight of the mast/antenna is borne by the rotator.  I immediately retighten the thrust bearing .

When I first started this I used a home made two leg clamp to stabilize the mast in the tower, but I ultimately abandoned it because I could swap the rotators so quickly that I never had a problem with the mast tipping out of position.

This was all with a 3el/40 SteppIR on a 10' Rohn mast.  I finally got sick of HamIV and put in a Yaesu 2800; I haven't had a problem in over 10 years now.  I still installed the mast on my 2800 with a 1/4" of clearance though.

Keith - AC9S