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Re: [TowerTalk] Phillystran and Pulleys

To: <>
Subject: Re: [TowerTalk] Phillystran and Pulleys
From: "W5CPT" <>
Date: Mon, 22 Jun 2009 13:50:52 -0500
List-post: <">>
With all due respect for Chas' experience, I have three antennas hung with 
Parachute cord.  One has been up about 8 years, one about 5 years and the last 
one has hung from my tower only 2 years.  I also have a halyard hung about 60' 
up in a tree that I pull antennas up and test them that has been up 8 years 
like the first dipole I hung when I moved back home.  I bought a 1000' spool in 
1991 at the HossTraders Hamfest in NH and still have about half.  I also use 
some of the good Black Stuff to guy verticals.

The only failure I have ever had was when I ran over with the lawn mower the 
end of one of dipole ends which had fallen into the grass. (oooops) .  It 
wrapped itself around the blade bearing and I had to cut it out.  All it did 
was shorten the end so I will have to tie a piece on when I want to lower that 
end of the dipole (or I could just let it fall) .

I think the key is to buy quality cord.  I have seen some really poor stuff in 
the $ stores but if you go to a good Outdoor store that serves climbers I think 
you can find some that is worth buying.  

Clint - W5CPT

  ----- Original Message ----- 
  From: chas 
  To: Jim Brown 
  Sent: Monday, June 22, 2009 1:12 PM
  Subject: Re: [TowerTalk] Phillystran and Pulleys

  Jim Brown wrote:
  > Crew,
  > I've got some of the smaller 1,200 lb test Phillystran that I bought 
  > years ago for a wire antenna project that didn't happen. It's too 
  > small for the 120 ft Rohn 25 that I'm preparing to install, but I'm 
  > wondering if it would work on my high dipoles that are up 110 ft in 
  > redwoods? 
  > The existing antennas, 80/40 fans fed with 150 ft of RG11, are held 
  > up by ropes (the "good" stuff that DX Eng and some other ham vendors 
  > sell) through good pulleys, but the black UV sheath of these ropes 
  > gradually abraid from friction as the trees sway, and eventually they 
  > fail. A 5/16-inch rope holding up my 160M Tee vertical failed after 
  > two years -- the sheath wore through completely, exposing the inner 
  > white material. Luckily I discovered it before it rotted in the sun 
  > and dropped, and was able splice in a new rope and pull it through. 
  > I'm not worried about the pulling strength, which is certainly 
  > adequate, but I am concerned as to whether the Phillystran would 
  > stand up to continuous flexing at the pulleys as the trees sway in a 
  > storm. Each antenna is counterweighted (about 100#) at one end, 
  > pulleys at both ends. 
  > Thoughts? Experience?  
  > 73,
  > Jim K9YC

  yeah!!  NEVER use parachute cord!!!  that stuff rots thru in a year 
  here in Houston.  I only use the double braided polyester 3/16" or a 
  size larger maybe.  the 700# test stuff.

  I have kept a mast up for 5 yrs now with this stuff and it still is 
  perfectly strong.

  geee, I thought everyone knew to not buy chute or riser cord for 
  anything but boot laces or some such.

  k5dam, houston, TX

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