[TowerTalk] Weight on ends of a OCF diploe

[Roger (K8RI) on TT]

I'll just be using a single pulley on each end of the 2 band fans and 
one at the 95' level on the 45G, but it'd be easy enough to add more 
pulleys so a single rope would tension all bands.  OTOH I'm a bit short 
on height to match those Redwoods.  Still, I don't have to worry have to 
worry about that much movement.  If it gets that bad the house will be 
gone too. I do have to worry about those severe spring ice storms though.

OTOH  A tornado only missed us by a few feet less than a decade ago. 
Unfortunately it left a big willow tree in our neighbor's yard to the 
S.  That thing makes a carpet out of half of our back yard. It's huge 
for trees around here at maybe 5' - 6'  across the base. The wind had it 
bent by nearly 45 degrees. The cracking sounded more like a moan turning 
into a scream and just as it was starting to break, the wind stopped 
abruptly, the tree snapped upright and threw a limb that was over a foot 
in diameter over 50 feet up wind into their neighbor's yard to the West.

73

Roger (K8RI)


On 8/12/2016 Friday 2:37 AM, Jim Brown wrote:
> On Thu,8/11/2016 10:02 PM, Roger (K8RI) on TT wrote:
>> 5/16ths is over 1700# strength, but a bit more expensive. 
>
> FWIW, I use the 5/16-in rope because it's easier to grab hold of to 
> pull tension on my very high dipoles. 3/16-in (and even 1/8-in) is 
> plenty strong enough for most antennas that aren't very high.
>
> Wes, N7WS, described a system similar to one I rigged here soon after 
> I moved here, with help from Ira, K2RD, and others. I replaced it with 
> the system of pulleys that I now use because it allowed me to get the 
> antennas higher, and it also allowed me to rig a 20/15/10 fan in line 
> with the 80/40 fan that had loading coils for 160.
>
> The system that Ira showed me how to rig had a continuous loop of 
> 5/16-in that he launched over a limb with his pneumatic tennis ball 
> launcher (he cleared the tallest redwood on my property  -- about 175 
> ft -- by at least 10 ft on the first shot). To that loop he attached a 
> pulley, then pulled the support wire through the pulley, then pulled 
> the pulley it all the way to the top.
>
> That system survived at least one winter without a weight, because 
> there was enough "give" in the way the pulley was rigged to allow for 
> sway, but I'm not confident that the loop rope would have survived 
> over that limb for 10 years. :)  Wes's experience suggests otherwise.
>
> 73, Jim K9YC
>
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-- 

73

Roger (K8RI)


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