Replacing the HAM-M with HAM-4 on Tri-Ex LM-354 HELP

[W7FSI]

My HAM M has pretty much died as in No Brake whatsoever. I have a nice nearly new HAM 4 that I want to install when tower is Cranked down to 20 plus feet. Problem is I would like to leave the Tribander and 6 meter beam and 2 meter beam on the 16 foot mast in place on the Tower supported by the Thrust Bearing and Huh??....while I take out the old HAM-M and slip in the new HAM-4.

I am looking for helpful hints and tips on how to support and or brace the the Mast and Antennas while changing out the Rotor.....I am certain it can be done I just have not been able to find any help on line. I sure hope I can do this without removing three fairly large Beams and a double thickness mast.

Helpful suggestions, tips and any other help greatly appreciated.

Gary
W7FSI
Stanley, IDAHO

 

[prcguy]

You mention a thrust bearing so I would assume the rotor is mounted down inside the tower. If so the lower the rotor is from the top of the tower the better for what I'll try to explain.

You should be able to bolt two short lengths of Unistrut spanning the tower legs on the outside of the tower right at the top of the rotor. Then place another length of Unistrut connected to the two pieces attached to the tower legs and position this third piece so it rests against the mast right above the rotor with a pair of its oval cut outs centered about the mast. Then put a U clamp around the mast and into the third Unistrut to immobilize the mast at the rotor.

Then you would have to gently loosen the new U clamp around the mast while unbolting the mast from the rotor and pull the mast with antennas up just enough to clear the rotor but not high enough to drop out of the new U clamp and Unistrut. Then clamp the new U bolt tight, remove and swap rotor then loosen the new U bolt so the mast and antennas can sink down into the new rotor.

Does that make sense?

If the mast and antennas are not very heavy you might get away with grabbing them with a Gin Pole affixed high on the tower and deal with some minor alignment problems putting the mast back into the new rotor, but if the load is light enough that should work ok. If the antennas and mast are too heavy to fight with a GIn Pole then I would recommend something like the first explanation.

My HAM M has pretty much died as in No Brake whatsoever. I have a nice nearly new HAM 4 that I want to install when tower is Cranked down to 20 plus feet. Problem is I would like to leave the Tribander and 6 meter beam and 2 meter beam on the 16 foot mast in place on the Tower supported by the Thrust Bearing and Huh??....while I take out the old HAM-M and slip in the new HAM-4.

I am looking for helpful hints and tips on how to support and or brace the the Mast and Antennas while changing out the Rotor.....I am certain it can be done I just have not been able to find any help on line. I sure hope I can do this without removing three fairly large Beams and a double thickness mast.

Helpful suggestions, tips and any other help greatly appreciated.

Gary
W7FSI
Stanley, IDAHO