[TowerTalk] Help Needed Replacing Crank-Up Cable on US Tower
K7LXC at aol.com
K7LXC at aol.com
Tue Jun 6 09:16:57 EDT 2006
In a message dated 6/5/2006 9:02:43 A.M. Pacific Daylight Time,
towertalk-request at contesting.com writes:
> I just purchased and have brought home US Tower, model HDX-572MDPL, 72'
Duty tower from the estate of a SK.
> It has a motor drive whose design includes a postive pulldown feature.
> The tower contains 4 sections, was installed in 1999 and has had little
> Where I need help:
> US Tower recommends replacing the cable every 2-3 years, which may be an
overkill but is definitely erring on the side of safety. Since my tower is 7
years old I'd like to start out with fresh cabling.
The UST recommendation is known as a "weasel clause"; that is, if
something happens to your tower and you hadn't changed the cables, they can weasel
out of any liability. Tower manufacturers are insurance-driven enterprises so
it's no surprise they are reluctant to provide any helpful information.
The other gotcha is that there isn't anyone around who can do the cable
change anyway. I spent a couple of days at the factory to learn how to do it
and what I found out is that it's an involved and semi-complicated endeavor.
It's not something I would try myself.
I'll bet you a nickel that you don't have to do anything other than lube
the cables and you'll be good to go. The actual circumstances that would
require cable replacement are: 1) Excessive broken strands. Industry standards
allow you to have six broken strands before replacement is necessary. 2)
Excessive rust - not surface rust but real cancerous into the strands rust. 3)
Damaged cable. This would be kinks or flat spots in the cable. I doubt that your
cables meet any of the above criteria.
OTOH you should lubricate the cables annually at a minimum. Champion Radio
Products sells PreLube 6 which is recommended by the wire rope manufacturers.
You should exercise the tower a couple of times a month by running it up
and down. You should also park it at different heights rather than just at
the limit switches all the time. The cables can take a permanent set by
sitting on the pulleys at the same spot for years. By doing these 3 things, you
will prolong the service life of your cables.
BTW I have never personally seen a ham tower that the cables were so bad
that they had to be replaced. Some were pretty grungy but didn't meet the
Lube it and enjoy it and don't worry about replacing the cables.
TOWER TECH -
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