Hi Gedas,
Originally you used the flag on a flagpole as an analogy. Absent the flag, I see
little need for a lot of tension in the loop. Then if the flag is hoisted by
that portion of the loop located above the joining knot then the knot still sees
very little stress; it's just along for the ride. Remove the flag and attach the
antenna. Nothing changes.
Wes N7WS
On 11/27/2019 2:50 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
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