In a message dated 2/4/04 12:06:56 PM Pacific Standard Time, wk6f@pacbell.net
writes:
> I've seen a few postings arguing the good/bad points of torque arms.
> For a 25G, would the torque arms be an advantage, or would the regular
> guy brackets with six guys be better for torque control. I'm just
> getting back into this stuff after 30 years or so, and quite a bit has
> changed. Comments, please.
Yes, changed indeed. The traditional torque arms - those foot-long pieces
of steel bars at the tower end of the guy wires - have been used by hams for
years. Intuitively they should add some torsion resistance but when Rohn
updated their designs and calculations to conform to a new TIA-222 Tower
Standard
revision back in the late 80's or so, they found that the torque arms weren't
really doing anything except when the tower was being climbed. That's when they
introduced the guy assemblies with the oval rings and discontinued the bar
versions. Well, hams had apolplexy - "I've used them for 30 years and I've got
to have them!" - so Rohn began manufacturing them again.
Are they worth using? Probably couldn't hurt. Your call. With properly
tensioned guys, there isn't much actual twisting tower movement when the tower
is climbed regardless of the guy hardware so it's pretty marginal. OTOH most
hams don't know what their guy tension is - almost certainly too loose - so it
stands to reason that the torque arms might help in that kind of scenario.
Since the current specs call for the guy assembly with oval rings, follow
the LXC Prime Directive and use what the manufacturer specifies.
The six-way guy brackets - the Torque Arm Stabilizer Assembly (TA25) or
star bracket - are quite excellent for locking down the tower since they don't
allow any twisting movement of the tower - it all comes down the guys. I don't
know why you'd need a star bracket for 25G; if your antenna is that big, 25G
probably isn't big enough anyway.
Cheers,
Steve K7LXC
TOWER TECH -
Professional tower services for commercial and amateur
888-833-3104
_______________________________________________
See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless Weather
Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any questions
and ask for Sherman, W2FLA.
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
|