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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