In a message dated 96-04-26 17:26:12 EDT, you write:
>So what do the power companies, telephone companies, and CATV companies do
>to measure the tension in their guys and support cables? I don't know the
>answer to this question and maybe someone out there who does know could tell
us?
>
Stan --
Sounds like an interesting project. I can rent a real Enerpac 0-10K
pound load cell tension dynamometer locally for $40.00 per day. Sometime
soon would be a good time to do it since people are already using the Loos
device. Want to come up and help? Since I don't have any 3/16" EHS on my
tower, I'll have to find a station volunteer.
As far as measuring wire tension, the TIA-222-E gives several
methods. First of all, the initial guy tension is normally 10% of the
published breaking strength (3/16" EHS, 3990 pounds breaking strength - guy
tension should be 400 pounds) with upper and lower limits of 15 and 8 percent
respectively. The conditions should be windless and a measurement of the
ambient temperature should be taken since the tension varies with
temperature.
1. The Direct Method is with the aforementioned dynamometer. The exact
method was discussed here a couple of weeks ago and I won't repeat it now.
Another instrument called a strand tensionometer can be used but is
relatively expensive (the Enerpac is 'only' $850.00).
2. The Pulse Method is an indirect technique where the vibration of the guy
is measured. One sharp jerk (is he on this reflector?) is applied to the guy
cable close to the bottom termination causing a pulse or wave to travel up
and down the cable. The pulse is timed and the result is cranked into a
formula.
3. The Tangent Intercept is another indirect method where a line of sight
is established which is tangential to the guy cable near the anchor end and
which intersects the tower leg a distance (tangent intercept) below the guy
attachment on the tower. This actually measures the sag of the guy wire.
Again, you crank the info into a formula to arrive at the answer.
I think that utility companies also use the above methods for their
requirements. If there are other ways of doing this, I am not familiar with
them.
Hope this is a usefull contribution to the contest reflector and is low on
the CRAP scale (and I'm not sure how THAT'S measured!).
73, Steve K7LXC
Tower Tech -- professional tower supplies and services for amateurs
(Can I say that?)
>From Dravland, Todd" <ToddD@dci.state.sd.us Sat Apr 27 01:47:00 1996
From: Dravland, Todd" <ToddD@dci.state.sd.us (Dravland, Todd)
Subject: Loos Tension Guage
Message-ID: <31816F8B@sdmailgw.state.sd.us>
>So what do the power companies, telephone companies, and CATV companies do
>to measure the tension in their guys and support cables? I don't know the
>answer to this question and maybe someone out there who does know could
tell
>us?
>
>Stan w7ni@teleport.com
>Aloha, OR
Stan,
I have a crew of technicians that do tower maintenance for towers used in
Public Safety communciations. The towers they maintain and inspect range in
size from 100 ft to 450 ft and EHS guy sizes from 1/2 to 9/16 inch. They use
a tension gauge manufactured by Penn-Tech Intl. Inc. out of West Chester,
PA. tel (215) 692-4436. I bought the two we have back in 1993 and from
what I remember the cost then was approx $1,200 each. They are NOT cheap,
and I have used one on the guys at the W0SD station towers and they are very
easy and fast to use. Just place the guy wire between the two hooks and
move the handle down which in turn moves a center piece that pushes against
the guy to measure the tension, read the gauge, and obtain the resultant
tension in pounds from the calibration charts for the particular guy size in
question. Perform this 3 times on each guy wire and take an average. Very
similar to the Loos gauge in operation, it appears. However, it is
designed ONLY for EHS. I have not personally compared the results of this
with the dynamometer setup we also have, but from what I have seen on the
results from my field technicians the two methods compare very closely. This
is certainly an item that is out of my price range, but sure seems well
worth the money as far as quality and ease of use. . Can't tell you what
the other organizations use that you mention above. Hope this helps.
73, Todd
WD0T
toddd@dci.state.sd.us
>From Dale L. Martin" <kg5u@hal-pc.org Sat Apr 27 01:21:04 1996
From: Dale L. Martin" <kg5u@hal-pc.org (Dale L. Martin)
Subject: Rain Static
Message-ID: <199604262320.SAA23574@hal-pc.org>
You sent:
> Seattle has a lot of rain, but it doesn't seem to have the static quantity
> that I remember from the Midwest. Maybe our milder rainstorms don't
> impart the same amount of charge to the raindrops. (kinder, gentler
> rain...thousand points of light...wouldn't be prudent...) So, any of you
> Texas or Midwestern gentlemen with big backyards want to try this?
>
Ward,
When I was in the Navy and stationed at the Naval Comm Station at
Keflavik, I had a station set up in my barracks room. The antenna
was an end fed wire. I can remember snows that we had there (it
really never got over a foot deep up there) really created havoc on
my receiver (a bigtime SX-110--hey! this was 1964, afterall). The
first time I heard it, I didn't know where it was coming from, but
there was this zzzzzzzsszszszsPOP sound over and over about
every five or six seconds. I quickly determined it was coming from
inside the receiver. I disconnected the antenna and got a jolt! I
found that if I held the wire (without any part of me touching the
radio) I could draw an arc of about a half-inch or so. Pretty
potent stuff, that snow!
I don't recall any similar phenomena or problems with the rain, though.
73,
>
>
Dale Martin, KG5U
Houston, Texas
http://www.hal-pc.org/~kg5u
>From Douglas Zwiebel <KR2Q@worldnet.att.net> Sat Apr 27 00:52:11 1996
From: Douglas Zwiebel <KR2Q@worldnet.att.net> (Douglas Zwiebel)
Subject: precip static: hints
Message-ID: <199604262352.XAA12976@mailhost.worldnet.att.net>
Come on guys (gals)....I know the answer is out there! THINK about this:
1) SNOW static is just as bad a rain static...not much LIGHTNING in snow!
2) Is the "static" due to charges imposed ONTO the element FROM the rain???
Keep thinking ;-)
>From Mr. Brett Graham" <bagraham@HK.Super.NET Sat Apr 27 01:36:21 1996
From: Mr. Brett Graham" <bagraham@HK.Super.NET (Mr. Brett Graham)
Subject: 1st Annual Dayton Internet DX Contest
Message-ID: <199604270036.IAA11100@is1.hk.super.net>
N3ADL said:
The 1st Annual Dayton Internet DX Contest is a go for this year.... Rules
follow....
You MUST buy said DX a beer in one of the hospitality suites.
Why didn't someone think of this last year, when I was there? Damn!
I believe VS6WV/XU6WV is going this year, so keep an eye out for him as
he'll be a quadruple mult...
73, VS6BrettGraham bagraham@hk.super.net & vr2bg@harts.org.hk
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