Re: [TowerTalk] Three Questions for HDX-555 Tower Project

[KJ0M <kj0m@mchsi.com>]

>  > 2.  Comments from hams with experience as to whether or not the 
> raising fixture will lift the tower from horizontal to verticle with 
> a 21 ft chromolly mast (2 in., 140 lbs), a TH7, and a XM240 
> installed without the tower crashing back to mother earth?


I just finished a project using the TX-472 MDP and the HD-80 heavy 
duty raising fixture. I installed a 22' mast (about 120#),a Force-12 
240/230 (about 50#) 14 feet above the top of the tower and a Force-12 
5BA (about 80#) right above the thrust bearing. I first installed the 
mast and both booms with the tower horizontal. I left the lower boom 
a bit loose so that I could keep it parallel to the ground while 
working on the top boom. I then raised the tower enough to turn the 
top boom so that it was pointing at the ground and added the 2 
elements to that half of the antenna. I then raised the tower 
vertical, rotated 180 degrees and lowered the tower back down so that 
I could add the other 2 elements to the other half of the top 
antenna. I then turned the still somewhat loose boom for the bottom 
antenna so that it was pointing in the correct direction and I 
repeated the procedure, adding elements to each half of that boom in 
turn. Basically I installed both these antennas, one with a 24 foot 
boom and the other with a 33 foot boom using nothing more than a 
short ladder for attaching elements to the booms without needing any 
more help than it took to lift and install the 120# mast while the 
tower was horizontal. It just takes lots of time, mostly slowly 
tilting the tower up/down, etc.

I do have a jig that I rest the tower in once it's off the ground. 
This is a safety measure in case something would give. This cradle 
will hold the tower as I crank up the tower. I periodically move the 
cradle so that the tower would drop only an inch or so if something 
broke.

Please note that the tower was not fully loaded with antennas while 
it was horizontal (antennas too large physically). The only thing 
going up from a complete horizontal position was the mast and 2 
booms, but this is the majority of the weight. The elements were 
added once the tower was up to about 45 degrees from horizontal. At 
45 degrees, the load is a bit less than when the tower is completely 
horizontal.

YMMV.
--

73,

de KJ0M
Jim
._._.
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