You have a rowboat that'll carry you and any one of the three and you've got to get grain, chicken and fox all across a body of water without ever leaving a fox/chicken or chicken/grain pair alone on either side. I think it was XKCD (Randall Munroe) who pointed out the real solution: Leave the fox. Foxes aren't domestic animals.*
Of course, he is brilliant.
Me, what I have is perspiration. I also had to get four 250 foot runs of not-very-flexible LMR-400 coax from the roof of an oversized two-story building through a conduit run that included not less than nine 90-degree bends, four of them in very close pairs, including one into a vertical. open-fronted wire duct above a suspended ceiling. The conduit wasn't big enough to run them one at a time, so there was a fat bundle to fight. --Oh, and two of the 90s are above the ceiling, between a wall and a lighting fixture, requiring vertical-limbo skills to reach.
The usual way to do this, assuming you are insane or desperate enough to make the attempt, it to station a person at each end and every 90 or close pair of 90s, and everyone helps the thick, awkward mess along. It works well.
That would call for at least six and preferably seven people. I had four, two of whom had better things to do -- oh, and about 25 feet of the run wasn't in conduit, but through a very "busy" raised floor under an in-use control center.
We did it, mostly by me bouncing between three of the worst corners (yes, including the two above the ceiling) and the application of plenty of brute force and utter guile on everyone's part, but it wasn't quick and it certainly wasn't easy.
I won't know if we "killed" any of the cable runs until later today An overlooked kink will destroy the stuff worse than a network cable. Wish me luck -- I'll be connectorizing the bottom ends and applying a Time-Domain Reflectometer. What's a TDR? Think of it as "radar on a rope:" it bounces signals off the far end and looks to see how well they make the round trip, with a presentation similar to a radar A-scope. I hope not to see any bogies.
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* Leave the fox and grain, take the chicken across. Leave the chicken, go back and get the grain. Goodbye, fox! Good luck!
May all of your traces look like this:
ReplyDeletehttps://en.wikipedia.org/wiki/File:TDR_trace_of_cable_terminationed_with_its_characteristic_impedance.jpg
I never had to pull coax through buildings, just airplanes.
May your cable be un-kinked, and all else in working order. Why let the fox go, that's another meal! Tie a little e around his neck, and make him swim behind the boat with the grain and the chicken. I never could get it the spirit of those things, they made no sense. Oh, and please tell Tam that pea-nut butter and Mayonnaise DO go together, on a fried balogna sammich... blame the Cub Scout manual I got it from MANY moons ago....
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ReplyDeleteThe other day when you were musing over how long a cable run was, I was puzzled why you didn't just break out your TDR tool. Your shop has Ghz bandwidth spectrum analyzers, you gots to have those type of whiz-bang gadgets floating around, unless your sticky-fingered ex-co-worker wandered of with it, as well...
Don't envy you that cable run... Hope it specs out okay!
ReplyDeleteAnon, I wanted to know how long the path was before I cut the cable. I pulled in a flat woven wire-pulling tape (like pull string, but tougher) and read the distance from it, plus additional distance red vial a "traveler" device.
ReplyDelete...We were checking some RG-6, basic CATV coax, for length. This is the good stuff that has the length to that point automatically printed on it every three feet, very handy -- except this spool, the beginning, end and every point in between have the same number, some 2800 feet: the counter/printer was stuck! Sheesh.
"...except this spool, the beginning, end and every point in between have the same number, some 2800 feet: the counter/printer was stuck!"
ReplyDeleteHey! That was the roll I was supposed to get!
Figures.
ReplyDeleteI wish you luck on the cables. Never heard a TDR described as "radar on a rope" but is a quite apt description
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ReplyDeleteI have seen maintenance people pull electrical wires through conduit that was tight and had a lot of 90 degree turns with a literal fork lift. They first ran a rope through the conduit, hooked the wires to that, and then kept greasing the wires up and drove the lift truck away, pulling the electrical wires through the conduit. They said, " We hope that we don't skin any of the insulation off the wires inside the conduit." Yeah, I was about as dumbfounded as you.
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