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Re: [TowerTalk] Guy Tensioning

To: towertalk <towertalk@contesting.com>
Subject: Re: [TowerTalk] Guy Tensioning
From: Steve Maki <lists@oakcom.org>
Date: Sun, 23 Oct 2016 20:32:44 -0400
List-post: <towertalk@contesting.com">mailto:towertalk@contesting.com>
I've never owned a Loos, but have owned a couple Penn-Tech commercial tensionmeters.

I just looked at the chart for the TM-800 to see what could be gleaned related to the 7 strand vs 19 strand scenario that could be applied to the general case, and I have to admit I'm a little confused.

In the case of 9/16", the table converges at 3500 lbs which is exactly 10% of breaking strength (IOW, gauge deflection for 7 strand is the same as for 19 strand).

But for 5/8" wire, the curves never converge (7 strand always creates higher gauge deflection than 19 strand for a given tension).

The TM-800 is designed for 3/16" to 3/4" wire, but 9/16" and 5?8" are the only two sizes on the chart for which both 7 strand and 19 strand defection values are given.

Maybe this is a mistake, I'll look into it a bit more.

-Steve K8LX

On 10/23/2016 19:04 PM, StellarCAT wrote:

I was surprised at this thread! I hadn't been aware of any previous
threads related to the use of Loos gauges nor did I know they were not
meant for EHS cable!

Someone had said "when you get up to 10% tension they read roughly
right" (paraphrasing but I believe the essence is correct) ... well that
isn't so!

I JUST finished running the cables today for my new installation... 148'
rotating tower with 6 large monobanders on it ... Looks REALLY sweet ...
anyway the guy doing the tower work, Benny out of Tenn. (great guy -
great work - great prices) brought a Penn-Tech gauge with. It IS
designed for EHS ... I used it to set the top guy which is 5/16" (EHS
and 1/2 philly) ... so I took his gauge and compared it to my Loos model
B (and to his Loos PT2) ... the Loos B read ~630# on the 1/4" EHS guys
(middle and bottom sets) ... the PT2 read 680# ... the PT ... it read
400! 4 0 0 !!!

In my humble opinion that is scary far from where I THOUGHT it was -
like more than 50% of the actual rating shy of the desired tension spot
(660# with ~ 68degrees).

WOW. I was blown away. All the 7 years I had my loaded tower up in AZ I
had the same tension - so it too was under tensioned.

So I'm going to adjust the bottom set of guys using the PT and then once
it is set correctly at 660# I will then compare it to the LOOS and I'll
then have a comparison point I can pass along to anyone using the Loos
(model B)

Gary
K9RX

[I've been working on this project for 18 months - poured concrete in
December of last year ... FINALLY have it all up. I'm still not done as
the crane got canceled for our scheduled time and I was concerned it
would get pushed out too far so I asked if they'd do Saturday - w/o OT
since they canceled it - they said YES and we had 9 hours of listening
to that diesel engine yesterday ... so because of the rush I still have
to install the terminal boxes at the base of the 2 towers and wire
everything up (5 miles of control wire) but I was able today to just put
a power supply at the base of the antenna and use my SARK to check and
all 6 antennas - SWEET! Including a modified Optibeam OB4-40 that is
near perfect]



-----Original Message----- From: K7LXC@aol.com
Sent: Saturday, October 22, 2016 8:27 PM
To: towertalk@contesting.com
Subject: Re: [TowerTalk] Guy Tensioning

 The calibration chart that comes with the instrument is correct only
for the 19-strand wire rope it was designed for, which is what they use for
sailboat rigging.  The stiffness of the cable  determines the reading  as
much as does the tension.  The chart that comes with the gauge is WAY
off and
totally useless for EHS guy cable.  I'm sure it would be just as  far off,
if not more so, with phillystran.

 With the two pieces  tied together, they both have the same tension, so
the tension reading on the  wire rope has to  be the same as the tension on
the EHS, thus allowing me  to make up an accurate chart for 3/16 EHS.  That
same procedure would work  equally well with phillystran; I would make up a
separate chart for  each.

Howdy --

   Here's my 2 cents worth again. I conducted the same  test only I also
had a segment of HPTG4000 inline and you proved my point, which  is that
they
all read the same. As a wire rope has tension increased on it, it  becomes
more rod-like regardless of type of material. So what do your charts  say?
Are they similar or what? Are you dealing with a couple of percent or
something else? Inquiring minds want to know.

   BTW the Loos PT-2 will only measure HPTG4000 due to  the size of the
jacket but it does fine on it.

Cheers,
Steve    K7LXC

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