Can You Build a Fiber Test Kit On a Budget? 53
An anonymous reader writes "Have any Slashdot readers hacked together cheap test kits for fiber optic cable? More and more IT infrastructure is using multimode and single mode fiber optic cabling. Commercial test equipment is extremely expensive, running the gamut from a few hundred dollars for a basic light source, to tens of thousands for an OTDR. What equipment do you consider essential to your fiber kit? Is there a way to save costs when it comes to fiber test equipment? It is worth it to do so?"
Re:Just get.... (Score:5, Interesting)
I friggin love this site. And here's about as cheap as you're gonna get. Though it won't exactly test your landlines.
http://www.electronickits.com/kit/complete/fibe/ck1500.htm [electronickits.com]
Had to answer this question once... (Score:4, Interesting)
Had to answer this question once ourselves. Never got to the implementation phase, but the plan was to have one or two high-end test sets, and build the others out of the prototypes for the equipment we were building, and Lucent OptiStar NICs on Linux systems. IE, each protype would test the next, and we would have racks full of 1U Linux Boxen with Lucen OC-12 NICs. Can't find out of Lucent or Alcatel-Lucent is still making those things, but you can find used/refurbed OptiStar (?) SONET IP Nics for Linux (PCI) fairely cheaply. No idea if they work, but as low as $60 bucks. New, they were $10k to $6k. Searching for Optistar on Ebay or Google returns a lot of info. Or, searching for SONET PCI NIC. Or, just FIBER PCI NIC. You can probably set up a laptop with Gig-E, if you just want connection tests, regardless of which protocol you're going to use. Honestly, eBay/Amazon are your friends here. At times, you can find million-dollar test sets for $100 bucks (Adtech, Omniber, Cerjac...) Most are left-overs from when startups fail. Also depends on what you're testing.
I would use ... (Score:1, Interesting)
I used to build fibre optic cables and every cable that didnt have glowing bits when you pushed a laser down them seemed to test perfectly. So I would use a 5mW green laser and if any bits on the cable glow you know that cable is broken.
Re:Even though it doesn't (Score:1, Interesting)
languages evolve
"Begs the question" was a terrible translation of petitio principii in the first place, and the language never meant what people asserts it means. A proper translation from Latin would be "seeking the principles", which actually DOES describe the fallacy wherein assuming X (your principle) you make a long winded argument that eventually proves X (seeking it), which has nothing at all to do with "begging" or a "question" in the first place.
I hope people continue to use "begs the question" in its proper English meaning as you have, and that we can hold back the tide of linguistic Humpty Dumptys [wikipedia.org] who continue to insist on "evolving" the language to mean whatever they wish it to be.
The basic kit bag is cheap and easy to get (Score:4, Interesting)
You can get these used on eBay all day long for a few hundred dollars for the entire set (search terms: "fiber test*" "fiber patch*" "fiber splice*"). You may have to watch a few days for a bargain, but I'm constantly amazed at how often high-quality fiber test gear goes for a song on eBay. Purchase only name-brand gear, such as Fluke, Noyes, Microtest, TestUM, etc. (You can learn the name brands by looking at new-equipment listings at places like CDW).
There are many tutorials on the web showing how to use these tools, most from equipment vendors themselves, and some are even high quality video presentations. A useful starting point is http://fiberu.com/ [fiberu.com] (although it's become less useful since Fluke took it over).
The mini-maglite will instantly identify any fiber -- the light will be clearly visible at the far end of even a thousand-foot run. If high-power IR lasers are in use on the network, be careful to be wearing fiber goggles whenever looking at fiber ends, even at your own white light. You can't tell when a fiber is energized with high-power IR, since it's invisible.
The power meter lets you measure the light loss through a fiber path, which when correctly interpreted will give you performance information. Get one that reads tenths of a microwatt, and that also directly displays dB loss from a reference signal. If you know the installed fiber specifications (you can read these off the fiber jacket), you can compute the available bandwidth based on fiber length.
The fiberscope reveals otherwise-invisible defects in a connector so that you don't spend hours trying to make an unworkable connection work. Again, be sure you're wearing laser goggles if you don't have both ends of a fiber in your hands. Magnifying harmful IR radiation is very dangerous.
For routine work you don't need an OTDR. Besides measuring the length of a fiber, an OTDR will locate defects along a fiber span so you can locate and repair them. If you're not repairing cable, or splicing it, an OTDR is overkill. Fiber installers have such gear, and they'll be happy to use theirs on your network for a fee when you need that capability.