|To:||<email@example.com>, "TowerTalk" <firstname.lastname@example.org>|
|Subject:||Re: [TowerTalk] Tramming|
|From:||"Tower (K8RI)" <email@example.com>|
|Date:||Tue, 17 Aug 2004 19:56:35 -0400|
Yes, it would be nice to use Phillystran or other Kevlar products. But there are two real big negatives that will keep most from doing it:
Except for a tram, unless hauling something really heavy 4400 is plenty strong with a 4,000# plus rating and it was around 60 to 70 cents a foot.
I use a friction clamp, the same thing I use to pretension the guys. It's just a pair of grips that pivot on a metal plate. They only grip about 2 inches worth, but work like a charm.
Yes, you can use clamps for a temporary hook up, but I prefer something that grips at least an inch wide. These are also available commercially, but they are also expensive. It's also easy to make good safe clamps out of aluminum sheet/stock IF you have the tools. The dimensions aren't critical, but 1/2 inch stock is convenient. Cut out blocks 1 1/2 X 4 inches. Mark a line down the center lengthwise. Drill for at least two and preferably 3 screws. Drill the first holes all the way through of the proper size for threading, or just drill out to use bolts.
Then drill one block with holes that are a slip fit to the screws/bolts to be used.
Clamp the blocks together when drilling so there is no misalignment.
With the block bolted together drill two holes lengthwise mid way between the centerline and edge. Finish drilling this hole around 1/16" smaller than the OD of the Kevlar cable.
Use two blocks with the cable looped through the second as a safety just-in-case to prevent any slippage.
I'd use plain old wire rope before resorting to EHS for a tram line. It's much more flexible and 3/16" to 1/4 inch is *relatively* easy to handle.
Yes, it can be cut, but my last experience with *trying* to cut 6700 was to finally give up and get a cable cutter. It is easily damaged, but if the jacket takes a nick while being used as a tram line it really isn't going to hurt anything. OTOH if a guy takes a nick it becomes open to the elements and eventual weakening.
My 500 foot roll of 1/4 EHS came delivered in a steel banded coil of about
Yah, but I can pick up a 500 foot roll of 6700 with one hand. Matter of fact I have a coil of 1/4" EHS that has never been unrolled since I purchased it. (The dealer had a coil laying in the corner) I'm not sure just how much is there. What's it weigh per 100 feet? I'd gladly part with it for a good price as I'll never use the stuff. Offer enough and I'll throw in a Henry 2K4 with a brand new set of tubes and a spare pair of Eimac 3-500s. New Peter Dahl plate transformer. Works well, but relays are noisy like all the early Henrys. I was using it out in the shop with my Icom 751A, but sold the 751A.
Roger Halstead (K8RI, EN73 & ARRL Life Member) N833R, World's Oldest Debonair (S# CD-2) www.rogerhalstead.com
See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless Weather Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any questions and ask for Sherman, W2FLA.
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