In a message dated 99-02-22 09:20:32 EST, slay@hevanet.com writes:
> I had not been able to swing them the full 360 degrees for some time ... but
> still had about 270 degrees for awhile. The other day, I cranked the
tower
> down, climbed on the roof and tried to re-calibrate the antennas.
>
> I set the rotor control box to due north.
> Loosened the U-bolts on the rotor to mast clamp.
> Turned the mast with a slip-wrench til the antennas were pointed due north.
> Retightened the U-bolts.
>
> Then, I tried to swing the antenna and discovered that the antennas will
> only turn a total of 90 degrees. Then stops between West and North.
> Arrgghhhhhh.
>
> My guess is that I've probably stripped or otherwise chewed up some gears.
> Of course, I don't know what exactly is happening since I wasn't looking at
> the rotor while using the control box to turn it. Maybe something simple
is
> slipping .... but I doubt I would be so lucky. ;-)
Well, you haven't found the problem yet. Go back up on the roof and
loosen up the U-bolts again. Have an accomplice in the shack run the rotator
back and forth to see if the rotator still stops in this 'no load' condition.
If it does, then you have a rotator problem. If it runs fine, then you've
probably got some bind in the mast/thrust bearing area.
If you have a rotor problem, maybe Craig will give you some slack on his
warranty. I would have expected the rotor to last longer but they are the weak
link in the chain.
>
> ........
> Question #2
>
> Seeing as my tower, an old Tristao motorized crank-up (54ft) cannot
> physically fit a Tailtwister ... hence the use of the Ham IV, are there any
> suggestions as to what model rotator I might consider as a replacement to
> the Ham IV?
>
The Effective Moment of your installation is 2549 ft-lbs; the capacity
of the Ham IV is 2800 ft-lbs so it's not overloaded but right at capacity.
Since it was a re-built rotator, maybe it had a pre-exisiting problem that
toasted it after 3 years. Maybe you should consider a new rotator - that
should give you at least double the service life of the current one.
Cheers, Steve K7LXC
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