I am hoping that I will never have to worry about the "loose end" of my
rope ever getting loose and coming off the top pulley requiring me to
tilt over my tower to re-thread the rope thru the pulley.
Gedas, W8BYA
Gallery at http://w8bya.com
Light travels faster than sound....
This is why some people appear bright until you hear them speak.
On 11/28/2019 1:21 AM, Robert Harmon wrote:
Gedas,
I have been following this discussion with interest. I have a similar
arrangement on my tower. I have a 3 foot pipe extending out from the top
section with a pulley on the end.
A rope goes through the pulley and is attached to the center of an 80 meter
inverted V. Like you I can raise and lower the antenna with the rope. The
difference is
I dont have another pulley at the bottom and use a loop arrangement to raise
and lower the antenna. I have two cleats vertically mounted on a tower leg a
little over 3
feet apart and after hoisting the antenna up I wind the rope around the two
cleats. It takes approximately 10 wraps. What is the advantage of using a
loop arrangement
between two pulleys ?
Bob
K6UJ
On Nov 27, 2019, at 8:21 PM, Gedas <w8bya@mchsi.com> wrote:
I was wondering if anyone was going to ask that :-)
In the past what I have been doing is making a temporary loop (you know the kind
that if you pull on the ends with nothing inside the loop, the loop will
disappear).....well anyway once the double Bowline knot is hoisted up to the top of
the tower and wire antenna attached I create a temporary loop at the bottom and slip
it over a smooth curved 3/8" steel hook I have fastened to one of the tower
legs. It's not super easy to make because the line is fairly tight but not so tight
that I cannot make one. When it's time to lower the antenna I simply pull the loop
off that steel hook, pull the knot apart and lower the antenna like a flag.
Gedas, W8BYA
Gallery at http://w8bya.com
Light travels faster than sound....
This is why some people appear bright until you hear them speak.
On 11/27/2019 10:23 PM, Howard wrote:
Hi,
I'm sorry I don't have any additional knot information than what has already
been provided, however, I have a question. After you pull the loop for your
dipole to the top pulley, how do you intend to hold the rope in that position?
Howard, WA9YBW
On 11/27/2019 3:50 PM, Gedas wrote:
Hi Wes and TU. I am not sure I am positive what you mean by only a load on the
upper side of the knot.
I am going to have two pulleys, one at the top of the tower and one at the
bottom. I am going to have a single long rope threaded around both pulleys and
I am going to use a fisherman's knot or similar to tie the two together nice
and tight. Not going to be much tension in the rope at this point, maybe 10
pounds just to keep both sides of the line nice and tight with no slop.
Now, I was hoping for a single knot that not only joined the two ends of the
rope together but that also left me with an open loop so I could easily slip in
something like a temporary chain link etc and then attach one end of a dipole
etc to that link.
This way from the ground I would be able to hoist up or down that end of the
dipole as I pleased. Now, when the end of the dipole gets attached to the other
end of that temporary chain link etc and the dipole is up in the air stretched
tight there may be 30-40 pounds of tension pulling on that line. Since the two
pulleys are fixed that tension from the dipole will get translated to my ropes
going up and down the tower between the pulleys.
I have been doing this type of arrangement for 20 years but only with a pulley
at the top of the tower. Up until now I just had the long single rope looped
around a round aluminum cross member of my free standing tower.
There was some friction with the rope looping around the 3/8" dia round &
smooth diagonal but I never had a failure. This season I installed a meaty pipe across
the tower at about the 5' level and attached a pulley at each end (I am going to have
several ropes going up and down so I can support and mess with more then 1 antenna).
I hope that paints a more clear picture. So far I have had a lot of great ideas
and the only issue is me understanding their words and making my fingers tie
the knots the way I'm supposed to hi-hi.
Gedas, W8BYA
Gallery at http://w8bya.com
Light travels faster than sound....
This is why some people appear bright until you hear them speak.
On 11/27/2019 4:25 PM, Wes wrote:
I'm with the other Wes on this one. If I understand correctly you only have a
load on the upper side of the knot. I would join the ends with any old knot and
tie a alpine butterfly loop on the upper side of the knot:
https://www.animatedknots.com/alpine-butterfly-loop-knot or one I find easier
to tie, a bowline on a bight:
https://www.animatedknots.com/bowline-on-a-bight-knot
Wes N7WS
On 11/27/2019 2:06 PM, Wes Attaway (N5WA) wrote:
Gedas:
You have received a lot of good suggestions. Here is one more, and it is
pretty simple. You are apparently not going to be risking anyone's life.
You are going to hold up one end of a dipole and there may be 30-40-pounds
of tension..
I would just join the two ends of the Dacron rope with a simple square knot
and with 6-inches or so of each rope sticking out from the knot. Then tie
the two ends into a square knot. Tape the ends to the rope if you want to.
With constant tension this arrangement will never come loose. I have done
this many times over many years with ropes into trees and on towers, etc.
Constant tension on the rope will keep the knots nice and tight.
-------------------
Wes Attaway (N5WA)
(318) 393-3289 - Shreveport, LA
Computer/Cellphone Forensics
AttawayForensics.com
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