In a message dated 10/6/2006 8:32:31 P.M. Pacific Daylight Time,
towertalk-request@contesting.com writes:
> I just lost my stack of F12 antennas when a cable snapped on my 5 year
old U.S. Tower HDX-572MDPL while at full height. I may try to repair the tower
or replace it. Here are my questions.
1. If I repair the tower and install stainless steel cables how much should
I de-rate its lifting weight?
I don't think the SS cables are going to buy you much. They probably
have the same breaking strength as the stock 7x19 strand galvanized cable so
it's mostly six of one, half dozen of another.
You can't put in a larger cable because the pulleys won't take the bigger
stuff.
Sorry to hear about your catastrophe but that's what happens
occasionally. I've seen a couple myself where the main hoisting cable broke
but one was
a snagged cable on the way up and the other was probably overloaded causing
the cable to part.
Do you know what the failure mode was? Were you standing next to the
tower watching it when the cable broke? Typically the cables are fine for
years
under normal operation.
> 2. I also thought about extending the tower (with a crane) to full height
and attaching clamps to the sections and make it a non-retracting tower.
Have not found a suitable self supporting tower that I could adapt to the
present base. Any ideas pro or con?
A crank-up will not take the stresses of a more normally fixed
self-supporting configured tower; e.g. self-supporting Trylon, Rohn, AN, etc.
They're
good up to about 80 MPH (albeit down-rated significantly) and that's about
it. So pulling your crank-up up and fixing it extended is not recommended -
particularly since you've broken it once with the current load.
If you want to partially extend it and then block and lock the sections
from moving, it'd work but I wouldn't trust it too far.
> 3. I ordered the newest/largest MonstIR 40M<>6M antenna to replace my
stack. http://tinyurl.com/a2v25 (Looks like no more SO2R) I have been
searching
the WEB for owners of this newest release by SteppIR but haven't found any.
Lots of the 20M<>6M antennas out there. There are 11 of us on the waiting
list. Any info from current owners?
Like what? It's a pretty awesome antenna and puts a severe load on your
tower and rotator. Your crank-up sure won't handle it unless you retract it a
bunch to increase the load capacity. Dauphin County has a 70 MPH windspeed
but you're within 100 miles of the coast and the hurricane oceanline so I'd
err on the conservative side of things.
> 4. Are there any other U.S.Tower owners out there that have had this
problem with cables breaking in such a short lifespan?
The only ones I've seen were overloaded due to antenna load or the
cables snagged. As you've seen it doesn't take much to break a cable.
BTW the factory wants you to replace the cables every 3 years. It's
a weasel clause; that is, if something happens to your tower and you didn't
replace the cables every 3 years, they can weasel out of any liability.
They make a good product and have good customer support so I don't
think it was a factory problem.
Cheers,
Steve K7LXC
TOWER TECH -
Professional tower services for hams
US Tower authorized installer
Installer of more SteppIR antennas than anyone else in the world including 3
MonstIRs
Cell: 206-890-4188
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