Keeping in mind that none of my arrays are over 300 lb. The last few times
I changed out a rotor, it went pretty easy.
1 loosen the set screws on the thrust bearing
2 loosen the mast clamp on the rotor
3 this depends on the rotor being removed, but usually I use an 18" snap on
pry bar to raise the mast about 1/2"
4 Slip the hook from a ratchet strap into the bottom of the mast. If it is
particularly heavy, slip in two
5 ease off of pry bay and let mast rest on hooks.
6 attach other end of ratchet straps to top plate and ratchet it up as
necessary
7 tighten set screws in thrust bearing, then remove old rotor
Most times you only need to raise the mast a few inches to gain clearance
for removal and replacement. If it is more, many of the other suggestions
sound like they would work fine. Dragging a come along or chain fall up a
tower is awkward at best and I'd like to avoid it if possible. My ratchet
straps are rated for 1000lbs each.
73,
AB5GU Marty
In a message dated 5/25/2010 2:12:47 P.M. Central Daylight Time,
krgoodwin@comcast.net writes:
I used an old TB3 and some angle iron (actually unused tower braces
cut to the necessary length) to tie a TB3 to the tower legs with
u-bolt clamps. I drilled the holes in the 'angle iron' for the
u-bolts in place after affixing the TB3 to the mast and the other
ends of the 'angle iron'. I placed the TB3 onto the mast as the
crane was lowering the mast into the upper thrust bearing on the top
platform and down into the rotator on the lower platform. With the
lower thrust bearing in place, it should take some of the load normal
the axis of the mast off of the rotator. Of course, I have yet to
utilize the configuration but I assumed all I needed was some means
of keeping the mast secure when raised above the rotator with the
upper thrust bearing on the top platform taking the dead weight of
the mast/antenna and with the lower thrust bearing keeping the mast
vertical when removing the rotator. I am not even sure if I need to
raise the mast at all since the rotator clamp assembly on the T2X can
be disassembled allowing to pull the rotator out to side with the
mast in place. (The mast is not resting on the rotator but borne by
the upper thrust bearing.) I have pictures of what I call the K4TD
Memorial Thrust Bearing since Rick told me I needed more than just
one thrust bearing for keeping forces normal to the mast axis off of
the rotator. This arrangement also keep me from having to build a
third platform. Everything but the 3-element 40 meter beam came thru
Hurricane Ike with no problems. Ken K5RG
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