glen@aecom.YU.EDU (Glen M. Marianko) (06/01/88)
We're installing a fiber optic ethernet backbone here and I'm looking for some good fiber optic test equipment for my toolkit at low (1-2k) cost. That certainly rules out OTDRs leaving attenuation testers. Anyone have any recommendations on testers. I would like to do testing at both 850nm and 1300nm. Most companies sell either separate units or units with plug-in modules for both frequencies. Some (notably Phillips) sell a dual nm receiver, but still need separate light sources. Finally, is attenuation testing alone a good enough test for a fiber optic cable? For example, ethernet link A to B is down - pop off the fiber and attenuation test it. Or, I just connectorized a jumper cable, was it done properly using an attenuation test? ** Important aside: anyone have information on do-it-yourself, cheap fiber connectorization? I have no experience with this: can you just buy duplex fiber, SMA 906 or ST connectors, chop the fiber ends, polish it as best as possible with fine sand paper/wheel and connectorize it for short patch-cord use? What kind of extra losses can I expect due to such non-scientific connectorization? Any company sell a do-it-yourself kit. (Someone is probably going to want to flame me for this Q, but I need to know if it is possible/feasible.) -- Glen Marianko glen@aecom.yu.edu
ian@lassen.SGI.COM (Ian Clements) (06/02/88)
Test equipment and connectors can be purchased from: Siecor Corp. 489 Siecor Park Hickory, NC 28603-0489 704/327-5000
hans@umd5.UUCP (06/04/88)
In article <1820@aecom.YU.EDU> glen@aecom.YU.EDU (Glen M. Marianko) writes: > >Anyone have any recommendations on testers. I would like to do >testing at both 850nm and 1300nm. Most companies sell either >separate units or units with plug-in modules for both >frequencies. Some (notably Phillips) sell a dual nm receiver, >but still need separate light sources. > Photodyne sells an optical power meter (17XTF) which is calibrated at 820, 850, 1300, and 1550 nm. I think the price is about $1200. Note that this is simply a broadband detector, with appropriate internal compensation for the sensor's sensitivity at the various wavelengths. Unfortunately precision light sources are considerably more expensive. Fortunately our fiber modems emit light continuously, and we use them for light sources.
dsmith@uoregon.uoregon.edu (Dale Smith) (06/08/88)
In article <1820@aecom.YU.EDU> glen@aecom.YU.EDU (Glen M. Marianko) writes: > >Anyone have any recommendations on testers. I would like to do >testing at both 850nm and 1300nm. I looked at a bunch of them including Fotec, Photodyne, and others. I decided that I liked a unit from Ditel the best. They have a dual- wavelength light source (850, 1300) and they re-sell the Laser Precision AM 3500 power meter. You should be able to purchase the set for about $2,000. Both the light source and power meter have AC and nicad batteries and come with carrying cases. The Ditel part numbers are ULS-30xx (xx= connector type) for the light source and 3500 for the power meter. Contact is: Jane Brightwell (704) 328-5640 Ditel PO Box 3386 Hickory, NC 28603
wsmith@umn-cs.cs.umn.edu (Warren Smith [Randy]) (06/11/88)
In article <1820@aecom.YU.EDU> glen@aecom.YU.EDU (Glen M. Marianko) writes: > >Finally, is attenuation testing alone a good enough test for a >fiber optic cable? For example, ethernet link A to B is down - >pop off the fiber and attenuation test it. Or, I just >connectorized a jumper cable, was it done properly using an >attenuation test? > >** Important aside: anyone have information on do-it-yourself, >cheap fiber connectorization? I have no experience with this: >can you just buy duplex fiber, SMA 906 or ST connectors, chop the >fiber ends, polish it as best as possible with fine sand >paper/wheel and connectorize it for short patch-cord use? What >kind of extra losses can I expect due to such non-scientific >connectorization? Any company sell a do-it-yourself kit. >(Someone is probably going to want to flame me for this Q, but I >need to know if it is possible/feasible.) > > >-- Glen Marianko glen@aecom.yu.edu Attenuation testing alone is quite sufficient for straight fiber runs. If you start crossing jumpers and splices things get messy quickly. Its also better if you can rely on your fiber having a low loss and being reliable. If your fiber does break in the middle of a run (never happened here) you are basically out of luck if you can't find it by visual inspection of the cable. About do-it-yourself connectorization, it definitely is possible, since we've done it here. However there a few pitfalls to watch for. First and most important: buy a good microscope!! Looking at fiber with the scopes standard with many kits is not very informative. You need a scope with 100x magnification and good lighting. Avoid the ones that look light pen-flashlights. Being able to rotate the angle at which you look at the fiber face is very helpful for seeing fractures below the fiber surface. With experience I was able to get SMA connectors with very low loss that looked much better than the "professional" connectors done here by US West (theirs were biconic). However, it takes time to do the connections and the connectors and kit will cost you a fair amount of money. You might see if one of these companies like FOCS would be cost effective for your terminations. I should add that I don't know much about the recent developments in connectorization. I've seen some of the new stuff, but I have no idea how much it costs. Randy Smith ...ihnp4!umn-cs!wsmith wsmith@umn-cs.cs.umn.edu -- Randy Smith
garrett@udel.EDU (Joel Garrett) (06/14/88)
In article <5815@umn-cs.cs.umn.edu> wsmith@umn-cs.UUCP (Warren Smith [Randy]) writes: >If your fiber does break in the middle >of a run (never happened here) you are basically out of luck if >you can't find it by visual inspection of the cable. We had a break in one of our fiber cables last year and had a branch of the local phone company come out and take a look at it. They hooked up something called an Optical Time Delay Reflectometer and it gave us a very good idea of where in the breach the cable was. Our search was kind of confounded by having a lot of excess cable still on the spool on one side of the link, but by hooking up the OTDR on both sides of the cable and doing a little estimation based on building drawings we found the break a lot sooner than we thought. Before they came, we were ready to pull the cable out and replace it. >Randy Smith >...ihnp4!umn-cs!wsmith >wsmith@umn-cs.cs.umn.edu Joel Garrett inet: garrett@udel.edu
wsmith@umn-cs.cs.umn.edu (Warren Smith [Randy]) (06/21/88)
In article <2993@louie.udel.EDU> garrett@udel.EDU (Joel Garrett) writes: >In article <5815@umn-cs.cs.umn.edu> wsmith@umn-cs.UUCP (Warren Smith [Randy]) writes: > >>If your fiber does break in the middle >>of a run (never happened here) you are basically out of luck if >>you can't find it by visual inspection of the cable. > >We had a break in one of our fiber cables last year and had a branch of the >local phone company come out and take a look at it. They hooked up something >called an Optical Time Delay Reflectometer and it gave us a very good idea of >where in the breach the cable was. .... Good point. I neglected to mention the OTDR because the original question was about a low budget approach to installing fiber (and OTDR's are not cheap!). Like you, we were able to "rent" and OTDR from a local company (in our case a local power company that had a bunch of extra ones lying around). So I guess this might be a viable option for people in a similar bind. Randy wsmith@umn-cs.cs.umn.edu ...!rutgers!umn-cs!wsmith -- Randy Smith