On 10/14/2010 8:35 PM, Richard Beckett wrote:
> Can I use a non EHS cable to guy my Rohn tower.
> I purchased 3/16" steel
> galvanized cable; Cooper Campbell #7000627 from a Lowe's hardware
> store. It may be similar to aircraft cable, not sure. Can I use this
> cable to guy my Rohn 25G tower to 70 feet.
BUT look up the strength of that cable and then look up 3/16 EHS. It's
been my experience that most of this kind of cable only has a fraction
of the strength of EHS. OTOH I've climbed commercial towers over 20
years old guyed with "wire rope" using fine strands. OTOH they were 1"
in diameter and the towers were a lot taller. I don't know what the
tension was, but they'd ring like a tuning fork when struck with a
wrench. The one tower must be at least 30 - 35 years old as I was
climbing it 27 years ago
Would I climb one using that as guy wire? Again the answer is; sure if I
were still climbing towers.
But then comes the question, would I want to use that as guy wire, or
EHS for that matter. When hanging wire antennas from a tower that is
guyed with metal guy lines they are going to have an effect on the
antennas. Break them up with insulators and they will have less of an
effect, but that can add quite a bit of work and may cost as much or
more than the guy lines. I've climbed many a 90' ham tower guyed with
3/16 wire rope over the years and think it's fine for towers with small
to medium tribanders or just wire antennas. HOWEVER you have to inspect
it more often than EHS and it is definitely more fragile and susceptible
to rusting than EHS which uses fewer, but larger strands of a stronger
and more rigid alloy.
I have a 100' of 45 G guyed with Phillystran at 3 levels. The lower two
tier are guyed with 4000# test while the top tier is 6000# test and I
have a relatively large and heavy array of antennas on top. I also have
half wave sloping dipoles on 40 and 75, with a half sloper on 160.Due to
a driveway and other clearance issues I had to go with elevated guy
anchors which are monsters. The bottom 10' of each guy is 1/4" EHS.
I do not like heavy guy lines. They have a deep catenary which "acts
like" stretch. I know there are those who will argue this point but
I've used EHS in the past and find the light weight Phillystran to give
me a tower that is more steady than the EHS. The Phillystran, has a
catenary so shallow it's difficult to see even when sighting down the
guy line has more stretch than EHS, but that deep catenary "seems" to
provide more give than the stretch in the Phillystran.
I can coil up all 9 Phillystran guy lines and put them over one shoulder
with out straining. It's all I can do to lift one of the top guy lines
made of EHS in a coil. All of that weight is added to the vertical
vector of the guy line tension and provides a substantial force on the
bottom of the tower.
> Note: I do not plan to use
> anything but wire antennas at this time.
To me that would be a good reason for using Phillystran. OTOH
Phillystran is not cheap. Where the 3/16 wire rope is 20 or 30 cents per
foot (it was cheaper at Ace Hardware than at Lowe's) Phillystran is
currently $.99 to $1.39 a foot for HPTG 40001 (4000#) and HPTG 67001
The 3/16 wire rope is probably on the order of 600-800# test. 3/16" EHS
OTOH is 3,990# strength and costs 24 cents per foot in 500 foot
coils.and weighs about 42#. As size goes up it gets heavy in a hurry.
Also the strength of "wire rope" as found in hardware and discount
stores varies widely, particularly the imported *stuff*. It's likely the
hardware store can order the wire rope in different strengths. (with
different prices) Wire rope is also available on-line with strengths
close to that of EHS.
73 and good luck,
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