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Guy Wire questions

To: <towertalk@contesting.com>
Subject: Guy Wire questions
From: gdo@aloft.att.com (Glenn D. O'Donnell)
Date: Tue, 18 Jun 96 13:15:19 EDT
> guy wire Rohn recommends for it's guys.  Putting up 70' of 45G.  Have access
> to 1/4" galvanized guy wire, and want to make sure it's the "right stuff".
 
The 1/4" stuff should be plenty strong enough.  I used 1/4" on my 70' 45G
according to Rohn's specs.  They specify thinner (3/16 ?) on the lower set
of guys, but I bought the wire in a 500' roll so why go thinner?
 
> Along these lines, any comments on the use of dead ends vs. clamps?  I had
 
Go with the dead ends.  They're easy to install (lotsa work for the fingers,
wear gloves or get blisters) and have a proven track record for reliability.
The whole job looks a lot nicer, too.  Looking at them, one wonders why they
work at all, but they work like those Chinese finger trap gizmos.  The harder
you pull, the tighter they grip.  They also are lined with a gritty adhesive
to add friction.

> I will be using 2 sets of guys, and each guy anchor will be 56' away from the
> base.  One set at 35', the other at 70'.  They are as follows:
> 
>   top:                -------O-------------O------------------------
>                5.65'       27'                 57'
> 
>   bottom:     ---------O------------------------
>                 9.04'             57'

I had 5' to each insulator from the tower, then 39' (as I recall) for the
next length.  The 39' was taken from a chart in the ARRL antenna book that
shows length resonant on each of the bands.  The 39' doesn't look good for
17m, but I don't plan any 17m antennas for my tower.  It is, however, OK for
160/80/40/20/15/10 which WILL be on/near the tower.  After the 39' length, I
just took whatever was left to the anchors.

> Another question:  Any ideas on which end should be at the tower, and which
> should be at the anchor?  Oh yeah, will be using the Rohn torque arms at each
> level.  And, should I use another insulator at the tower end of the guys?

The torque arms will be nice for the top guys, but overkill for the lower set.
I wish I had the torque arms at the top and I may actually put them on.  When
the wind blows and you're at the top with big antennas, the twisting moment
feels pretty eerie.  I understand the tower is still mechanically sturdy, but
that extra confidence factor wouldn't hurt.

> I was thinking that the short 5.65' and 9.04' lengths could attach to the 
> tower
> directly without insulators.

Yup!

Good luck.  Like everyone else here, I'll add the standard disclaimer to check
with a professional engineer if you need guarantees for durability.  Let's
face it, I'm just another guy with some tower experience.  A local pro can 
factor in your local wind loads, soil characteristics, etc. not to mention
your local (ugh!) building codes and such!
 
It'll be a LOT of work, but the results will scream "Thank You!"   :-)
 
73 de Glenn, N3BDA

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