You might want to look at knots fishermen use.
Some, like the Palomar Knot (IIRC), equal the
line strength.
73, Dick, W1KSZ
On Fri, Oct 23, 2015 at 8:30 PM, Patrick Greenlee <patrick_g@windstream.net>
wrote:
> Don, most all knots are weaker than the line in which they are tied, i.e.
> the line will break at the knot before the undisturbed line will break. .
> That said, I like your suggestion as boom trusses are not long enough
> for economics to be an overriding concern that would prevent oversizing
> the Philly to allow for derating due to the knots.
>
> I would be very curious to know the reduction in breaking strength of a
> termination consisting of a piece of Philly run through a hole just a bit
> larger than the nominal diameter of the Philly in a metallic substrate with
> a figure of eight knot (AKA stopper knot) tied in the Philly. Perhaps
> someone with more knowledge of marlinspike seamanship could suggest a
> suitable knot which has a lesser strength reduction. Perhaps someone more
> familiar with Philly construction could comment on the differences between
> the stress/force distribution in Philly as opposed to popular rope
> construction such as double braid, twisted three strand, etc.
>
> Patrick NJ5G
>
>
>
> On 10/23/2015 12:51 PM, Big Don wrote:
>
>> For completeness in the Phillystran discussion, the "Lok-Cube" should
>> perhaps be mentioned.
>>
>> These were provided with 1990-vintage KT34XA antennas to terminate the
>> 1/8"
>> Philly boom truss..
>> This item is basically a one-inch-or-so on-a-side plastic cube with five
>> thru-holes in the axial direction,
>> one in the center and one in each corner, hole diameter slightly larger
>> than the Philly.
>> A diagram in the instructions showed how to weave the Philly thru the
>> holes.
>>
>> The Lok-Cube uses no positive clamping, all that keeps it from slipping
>> apart is friction of the Philly against itself, and the Lok-Cube, when the
>> termination is pulled tight. It is little more than a knot. Our XA has
>> been up, untouched for 25 years, including a couple of near-terminal
>> ice-storms, and the boom appears to be fine.....
>>
>> Just a thought here - our gut feel is you could attach Philly just by
>> tying
>> a knot similar to attaching a fishhook to a nylon leader. Maybe Grant
>> could
>> try some in his 20,000# tension tester and see if it slips or pops at any
>> significantly reduced strength...?? Might start with the good-old Clinch
>> Knot
>>
>> http://www.wideopenspaces.com/five-fishing-knots-you-will-ever-need-to-know/
>>
>> Don N7EF
>>
>> On Fri, Oct 23, 2015 at 9:31 AM, GMuller885--- via TowerTalk <
>> towertalk@contesting.com> wrote:
>>
>> Folks:
>>> I wish to thank all who have responded. I have gone to
>>> Phillkystran
>>> web site and talked with their engineers and have come to the conclusion
>>> that , YES I did use over kill on the size. However their conclusion was
>>> that
>>> there was no harm and no foul and the three clamps used at each terminus
>>> would work very well. They did recommend that the saddle clamps should
>>> be
>>> alternated starting with the saddle starting on the long side. As
>>> mentioned,
>>> " do not saddle a dead horse".
>>> Again thank all of you that responded.
>>>
>>> Gerald Muller K9GEM
>>> GMuller885@aol.com
>>> _______________________________________________
>>>
>>>
>>>
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>>> TowerTalk@contesting.com
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>>>
>>> _______________________________________________
>>
>>
>>
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