brad@terra.ucsc.edu (Brad Smith) (05/08/91)
We're on the market for a cable scanner. This will be used primarily to test twisted-pair cable runs. I have been evaluating the Pair Scanner from MicroTest. I'm impressed by all the functions this scanner can accomplish, but it seems a little too "idiot proof." It only reports the greatest reflection along a cable run. Something that would report all reflections would be more useful. Can anyone recommend any other scanners/TDR's that would be worth checking out? Thanks in advance, Brad Smith Computer Facilities Manager brad@cis.ucsc.edu
andrew@jhereg.osa.com (Andrew C. Esh) (05/10/91)
In article <15490@darkstar.ucsc.edu> brad@terra.ucsc.edu (Brad Smith) writes: >We're on the market for a cable scanner. This will be used primarily to test >twisted-pair cable runs. I have been evaluating the Pair Scanner from >MicroTest. I'm impressed by all the functions this scanner can accomplish, >but it seems a little too "idiot proof." It only reports the greatest >reflection along a cable run. Something that would report all reflections >would be more useful. Can anyone recommend any other scanners/TDR's that >would be worth checking out? > >Thanks in advance, > >Brad Smith >Computer Facilities Manager >brad@cis.ucsc.edu Microtest Pair Scanner? I'm not very familiar with that, and I don't feel like digging through all my product literature to find it. I saw the brochure and was not impressed enough to read it through. ANYWAY: We use a Microtest Cable Scanner for Twisted Pair, and for coax. It only finds the first major reflection, but it is useful. It gives voltage and noise information also. If you are looking for a scanner that gives multiple reflection readings, you need a Time Domain Reflectometer. That will show the cable reflections on a graph, with peaks and valleys where the reflections are along the line. If you have the velocity of propagation set right, the readout is in meters of cable, so you can find the break very quickly. The problem with the TDR is that it costs about ten times as much as as Cable Scanner. -- Andrew C. Esh andrew@osa.com Open Systems Architects, Inc. Mpls, MN 55416-1528 Punch down, turn around, do a little crimpin' (612) 525-0000 Punch down, turn around, plug it in and go ...
jpd@pc.usl.edu (Dugal James P.) (05/10/91)
In article <1991May10.140628.17601@jhereg.osa.com> andrew@jhereg.osa.com (Andrew C. Esh) writes: >ANYWAY: We use a Microtest Cable Scanner for Twisted Pair, and for coax. It >only finds the first major reflection, but it is useful. It gives voltage >and noise information also. > >If you are looking for a scanner that gives multiple reflection readings, >you need a Time Domain Reflectometer. That will show the cable reflections >on a graph, with peaks and valleys where the reflections are along the I am awaiting my Microtest cable scanner. This paragraph in the brochure convinced me to buy it: "Connected to an oscilloscope, Scanner's precision, high-speed, pulse- generating circuitry offers installers and other technicians a detailed view of the entire LAN, including transceiver, terminator, and multiple faults. In other words, you get the capabilities of sophisticated time domain reflec- tometers. But not the expensive price tag." Anyone tried this? Does it work as advertised? -- -- James Dugal, N5KNX Internet: jpd@usl.edu Associate Director Ham packet: n5knx@k5arh Computing Center US Mail: PO Box 42770 Lafayette, LA 70504 University of Southwestern LA. Tel. 318-231-6417 U.S.A.
butzer@rugby.cis.ohio-state.edu (Dan Butzer) (05/11/91)
Take a look at the Tektronix 1503C. I have the previous rev of the unit - the 1503B and an _Extremely_ pleased with the unit. I use it primarily to shoot my thin-net networks. Only downside is cost which is ~$5K. (IMHO worth every penny for an operation of our size.) --Dan
mtarrani@crash.cts.com (Mike Tarrani) (05/11/91)
In article <30794@rouge.usl.edu> jpd@pc.usl.edu (Dugal James P.) writes: >I am awaiting my Microtest cable scanner. This paragraph in the brochure >convinced me to buy it: > >"Connected to an oscilloscope, Scanner's precision, high-speed, pulse- >generating circuitry offers installers and other technicians a detailed >view of the entire LAN, including transceiver, terminator, and multiple faults. >In other words, you get the capabilities of sophisticated time domain reflec- >tometers. But not the expensive price tag." > >Anyone tried this? Does it work as advertised? > >-- >-- James Dugal, N5KNX Internet: jpd@usl.edu >Associate Director Ham packet: n5knx@k5arh >Computing Center US Mail: PO Box 42770 Lafayette, LA 70504 >University of Southwestern LA. Tel. 318-231-6417 U.S.A. I checked the brouchure that Microtest sent me and it turns out that a *200* MHz scope is required! Ever price one of those puppies? You can get a real TDR + Microtest Cable Scanner for the price of a 200 MHz scope, with money left over! Mike Tarrani crash!mtarrani@nosc.mil Senior Systems Analyst Beta Corporation San Diego, CA (619) 565-4504 x230 -- Mike Tarrani crash!mtarrani@nosc.mil Senior Systems Analyst Beta Corporation San Diego, CA
amc@cup.portal.com (Alan Michael Crawley) (05/11/91)
We do this sort of thing for a living. Hewlett Packard version of Microtest Cable Scanner is better. Biggest problem with all solutions (Scanner's, TDR) is no way to check near end crosstalk of installed twisted pair. Anybody have a way of doing that?
djdove@hprnd.rose.hp.com (Dan Dove) (05/14/91)
Brad, HP has a selection of cable scanning/qualification tools which may interest you. One of them looks very similar to the tool you mention... The other is called the 28687A Wiretest Instrument which was designed specifically to provide 10-BASE-T certification of your wiring. It measures (very accurately/reliably) the following: - Continuity (details failures ie: short 1-3, open 3-6) - Burst Noise ( Per the 10-BASE-T specs ) - Attenuation ( < .5dB resolution, 16dB dynamic range ) - Near End Crosstalk ( < 1dB resolution, 35dB dynamic range) It has a monitor, print, and continuous measurement capability, allows you to test from RJ-45 or 50 D-sub connectors, and will test up to 12 ports at a time. This product is highly recommended for site certification and maintenance. Contact your local HP Sales. Dan Dove HP Roseville Networks Division
djdove@hprnd.rose.hp.com (Dan Dove) (05/16/91)
In comp.dcom.lans, djdove@hprnd.rose.hp.com (Dan Dove) writes: > - Attenuation ( < .5dB resolution, 16dB dynamic range ) > - Near End Crosstalk ( < 1dB resolution, 35dB dynamic range) Oops! I meant to say ACCURACY. The resolution on both measurements is .1dB. > - Attenuation ( < .5dB ACCURACY, 16dB dynamic range ) > - Near End Crosstalk ( < 1dB ACCURACY, 35dB dynamic range) Dan Dove HP Roseville Networks Division
osyjm@warp.mhd.montana.edu (Jaye Mathisen) (05/17/91)
In article <119459@tut.cis.ohio-state.edu> butzer@rugby.cis.ohio-state.edu (Dan Butzer) writes: >Take a look at the Tektronix 1503C. I have the previous rev of the unit - >the 1503B and an _Extremely_ pleased with the unit. I use it primarily to >shoot my thin-net networks. Same here. Our 1503C has functioned flawlessly, and the ability to test active networks has been a real boon. I would certainly buy another one if needed. -- Jaye Mathisen,sysmgr 410 Roberts Hall,Dept. of Computer Science Montana State University,Bozeman MT 59717 PHONE: (406) 994-{4780,3931}
lanmaint@nssdcb.gsfc.nasa.gov (Dave Yoest) (05/21/91)
In article <3973@dali>, osyjm@warp.mhd.montana.edu (Jaye Mathisen) writes... >In article <119459@tut.cis.ohio-state.edu> butzer@rugby.cis.ohio-state.edu (Dan Butzer) writes: >>Take a look at the Tektronix 1503C. I have the previous rev of the unit - >>the 1503B and an _Extremely_ pleased with the unit. I use it primarily to >>shoot my thin-net networks. > > >Same here. Our 1503C has functioned flawlessly, and the ability to test >active networks has been a real boon. > >I would certainly buy another one if needed. >-- > Jaye Mathisen,sysmgr 410 Roberts Hall,Dept. of Computer Science > Montana State University,Bozeman MT 59717 PHONE: (406) 994-{4780,3931} We also use a 1503B and I personally feel that it is one of the best wire diagnostic tools we have. Not only do we use it for ethernet coaxial based systems, but we also use it for other coax systems such as video, and I would imagine it could also be used on non-coax based (twisted pair) systems as well, although I have yet to try it. Prior to the 1503B we used a 1503 (old,analog display,1970's technology) that did the job. Other than replacing the Ni-Cad batteries it also worked flawlessly (and still does) but did not have many of the features the 1503B has to TDR active ethernets. While it does require some amount of operator/tech expertise to use, it really isn't complicated. If you can find it, an excellent article was published in the November 1988 issue of LAN magazine titled TDRing Ethernet, by Bob Agnes. It specifically talks about using the 1503B and also has copies of the display showing most of the faults commonly found on ethernet. Dave Yoest LAN M&O Section Supervisor NASA/Goddard Space Flight Center Greenbelt, Md. USA 20646 DYOEST@128.183.43.16 DYOEST@zaphod.gsfc.nasa.gov