peter@ficc.ferranti.com (Peter da Silva) (05/30/90)
We just had new phone service hooked up, two lines: one for data, the other for voice. Instead of designating one jack for data and hooking up the rest for voice, my wife let them install a new kind of wallplate with two lines at each point: +-------------+ | | | +--+ +--+ | | | | | | | | +--+ +--+ | | | +-------------+ I presume they have hooked red-green up on one line, and yellow-black on the other. I haven't had time to check it or even pop a plate (moving is *such* fun), but if they did this I should expect some crosstalk. Has anyone else seen this setup? If there is a crosstalk problem, what should I do? `-_-' Peter da Silva. +1 713 274 5180. <peter@ficc.ferranti.com> 'U` Have you hugged your wolf today? <peter@sugar.hackercorp.com> @FIN Dirty words: Zhghnyyl erphefvir vayvar shapgvbaf.
julian@bongo.uucp (Julian Macassey) (05/31/90)
In article <8435@accuvax.nwu.edu>, peter@ficc.ferranti.com (Peter da Silva) writes: > We just had new phone service hooked up, two lines: one for data, the > other for voice. Instead of designating one jack for data and hooking > up the rest for voice, my wife let them install a new kind of > wallplate with two lines at each point ... There is a certain amount of dejavu here: Quad wire in phone installations causes crosstalk. The jacks that were installed will not be the cause of the crosstalk. So you can't blame the Mrs. for this one. Crummy wire could be a cause of crosstalk. You say that you have Red, Green and Black, Yellow wire. This stuff is called quad wire. It is not twisted pair wire. If you use quad wire you will get crosstalk between the two pairs. The right wire to use is "Twisted pair". This stuff has the following color code: White/Blue, Blue/White. White/Orange, Orange/White. White/Green, Green/White. As a general rule, the minimum number of pairs in twisted pair cable is three. Yes there is two pair around, it is rare but I saw some yesterday at Pacific Palisades - Surf was lousy though. The jacks are not the source of the crosstalk. I do this sort of thing all the time. In about an hour I am going to an establishment that has telephone and Appletalk sharing the same cable and coming out to duplex jacks. It works because it is twisted pair. So, if you have twisted pair, no worries. If you have quad - yuck. But the quad may work. Julian Macassey, n6are julian@bongo.info.com ucla-an!denwa!bongo!julian N6ARE@K6IYK (Packet Radio) n6are.ampr.org [44.16.0.81] voice (213) 653-4495
dave%westmark@uunet.uu.net (Dave Levenson) (05/31/90)
In article <8435@accuvax.nwu.edu>, peter@ficc.ferranti.com (Peter da Silva) writes: > We just had new phone service hooked up, two lines: one for data, the > other for voice... > I presume they have hooked red-green up on one line, and yellow-black > on the other ... if they did this I should expect some crosstalk. > Has anyone else seen this setup? If there is a crosstalk problem, > what should I do? If they really used the two pairs available in standard quad, as you suggest, then you will probably experience crosstalk, if there's any significant cable run. It isn't caused by sharing a duplex jack, but by the cable. For two-line service, they should use a cable with two (or more) twisted pairs. If they did, they would probably have connected one line to the blue-white pair and the other to the orange-white pair. If they did that, you shouldn't experience crosstalk, regardless of the connectors used. Dave Levenson Voice: 201 647 0900 Fax: 201 647 6857 Westmark, Inc. UUCP: {uunet | rutgers | att}!westmark!dave Warren, NJ, USA AT&T Mail: !westmark!dave [The Man in the Mooney]
peter@ficc.ferranti.com (Peter da Silva) (06/05/90)
In article <8500@accuvax.nwu.edu> julian@bongo.uucp (Julian Macassey) writes: > There is a certain amount of dejavu here: Quad wire in phone > installations causes crosstalk. The jacks that were installed will not > be the cause of the crosstalk. So you can't blame the Mrs. for this > one. [ lots of detailed explanation of stuff I already know ] Yes, yes, yes. I know all that. I didn't explain all my reasoning because I assumed that folks here would know it all already. This is an existing apartment, wired with (I presume, since all other apartments I've been in have been wired this way) quad wire from the network demark to each wall plate. Normally I'd have one line... quad to the wall plate ... for the data line and the other wires... again, quad to the wall plate ... for the voice lines. Each cable is now one wire on quad. Crosstalk should be minimal, unless they run the quads next to each other in the same conduit for any significant length. With this setup, all the quads have both lines next to each other and some crosstalk is to be expected. It's a small apartment, so it might not be so bad. Sigh. Next time I ask a question I'll be sure to include full background on everything, my life history, and the whole shmeer... `-_-' Peter da Silva. +1 713 274 5180. <peter@ficc.ferranti.com> 'U` Have you hugged your wolf today? <peter@sugar.hackercorp.com> @FIN Dirty words: Zhghnyyl erphefvir vayvar shapgvbaf.