bradc@cognos.uucp (Brad Cameron) (09/15/88)
Could someone fill me in on the pin-out of the 4-wire modular telephone connector used in North America? I am particularly interested in finding the TIP and RING signals. Thanks in advance ! 8-) -- Brad Cameron uucp: decvax!utzoo!dciem!nrcaer!cognos!bradc Cognos Incorporated mail: P.O. Box 9707, 3755 Riverside Drive, (613) 738-1440 Ottawa Ontario, Canada. K1G 3Z4
henry@utzoo.uucp (Henry Spencer) (09/17/88)
In article <4063@enterprise.UUCP> bradc@cognos.UUCP () writes: >Could someone fill me in on the pin-out of the 4-wire modular >telephone connector used in North America? I am particularly >interested in finding the TIP and RING signals. The middle two are tip and ring. It is not particularly useful to ask "which is which?", because the usual modular wiring components reverse them quite casually. Modern phones are designed to be insensitive to the polarity. The outer two wires are not normally connected in residential wiring. They get used for various purposes in commercial phone systems and other specialized applications. -- NASA is into artificial | Henry Spencer at U of Toronto Zoology stupidity. - Jerry Pournelle | uunet!attcan!utzoo!henry henry@zoo.toronto.edu
jim@trsvax.UUCP (09/17/88)
They are the two middle connections (the outer two and yellow and black) are used for everything from a secondary phone line to signalling buzzers to LANs to transformers for the glow-in-the-dark effect. James T. Wyatt (UUCP:decvax!mirosoft!trsvax!jim) KA5VJL
doug@ninja.UUCP (Doug Davis) (09/18/88)
>The middle two are tip and ring. It is not particularly useful to ask >"which is which?", because the usual modular wiring components reverse >them quite casually. Modern phones are designed to be insensitive to >the polarity. > >The outer two wires are not normally connected in residential wiring. >They get used for various purposes in commercial phone systems and >other specialized applications. Actually some stuff (older phones and phone stuff) will be sensitive to polarity. If i remember correctly, (some one will undoubtably correct me if I am wrong) in a "properly installed system, the green wire is tip, the red wire is ring. On residental phone installations, if you have two lines, you can have RJ14C jacks installed. This gives you both lines on the same modular connectors. In this case the black wire is supposably tip, likewise the yellow wire is ring. Be careful though, some really ancient residental systems have +5 to +7 vac flowing though the yellow/black pair. This was to supply lights for the dials on older telephones. "Never worked for the fone company, just used to hack on fone stuff a bunch a few years back. Now, where did i put that 600ohm/600ohm transformer?" --- doug davis \ | / Lawnet -------------------------------- * - / | \ { killer, convex, motown, tness7, sys1}!ninja!doug 1030 Pleasent Valley Lane Arlington Tx, 76015 (817) 467 - 3740
jans@tekgvs.GVS.TEK.COM (Jan Steinman) (09/19/88)
<The outer two wires are not normally connected in residential wiring. They get used for various purposes in commercial phone systems and other specialized applications.> The outer two are often used for a second line. Many two-line phones and accessories are wired this way, including the DAK two-line answering machine and the RatShack two-line switches. It is also very convenient for installing a second line -- if you add wiring, be sure to run all four if you are remotely considering a second line! :::::: Software Productivity Technologies -- Experiment Manager Project :::::: :::::: Jan Steinman N7JDB Box 500, MS 50-383 (w)503/627-5881 :::::: :::::: jans@tekcrl.TEK.COM Beaverton, OR 97077 (h)503/657-7703 ::::::
jbn@glacier.STANFORD.EDU (John B. Nagle) (09/20/88)
Tip/ring polarity doesn't matter for nonelectronic dial phones, but most Touch-Tone (tm) dials need the right polarity for their power. This is certainly true of the traditional Western Electric product. John Nagle
henry@utzoo.uucp (Henry Spencer) (09/22/88)
In article <3958@tekgvs.GVS.TEK.COM> jans@tekgvs.GVS.TEK.COM (Jan Steinman) writes: >The outer two are often used for a second line... I should have thought of that, but my second line doesn't use that method (it's on a separate jack altogether) so I didn't. It may make a difference whether you order the second line when the wiring is being run or later (mine was later -- moving into an already-wired apartment -- and the Bell man may have been reluctant to trust the previous installer's wiring). -- NASA is into artificial | Henry Spencer at U of Toronto Zoology stupidity. - Jerry Pournelle | uunet!attcan!utzoo!henry henry@zoo.toronto.edu
henry@utzoo.uucp (Henry Spencer) (09/22/88)
In article <17723@glacier.STANFORD.EDU> jbn@glacier.UUCP (John B. Nagle) writes: > Tip/ring polarity doesn't matter for nonelectronic dial phones, but >most Touch-Tone (tm) dials need the right polarity for their power. >This is certainly true of the traditional Western Electric product. No, only of the *old* Western Electric product. The very early Touch- Tone dials needed specific polarity. All the modern ones, even from WE, have a diode bridge that eliminates the problem. I'd be surprised to find any modular-jack phone that cared, since reversals are normal in modular wiring, but one might find an occasional oldie converted to modular jacks unofficially. For that matter, I seem to recall seeing mention that some old dial phones worked better with one polarity than with the other -- with annoyances like slight bell noises during dialing if you got the polarity wrong -- but I've never confirmed this personally. -- NASA is into artificial | Henry Spencer at U of Toronto Zoology stupidity. - Jerry Pournelle | uunet!attcan!utzoo!henry henry@zoo.toronto.edu
larry@kitty.UUCP (Larry Lippman) (09/23/88)
In article <1988Sep22.060244.3959@utzoo.uucp>, henry@utzoo.uucp (Henry Spencer) writes: > For that matter, I seem to recall seeing mention that some old dial > phones worked better with one polarity than with the other -- with > annoyances like slight bell noises during dialing if you got the > polarity wrong -- but I've never confirmed this personally. It is indeed true that some ringer designs are prone to "bell tapping" during dialing. While ringers are designed for operation on 20 to 30 Hz, some models are sensitive to the large DC transients which occur during rotary dialing. These ringers are "biased" using a permanent magnet and a bias spring, therefore rendering them somewhat polarity sensitive to a DC pulse. The most expedient way to eliminate bell tapping within a telephone set is to make certain that one ringer lead is connected to a break contact on the switchhook which disconnects the bell when the set is off-hook. For permanently bridged extension ringers, the bias spring tension can also be increased to correct the problem. <> Larry Lippman @ Recognition Research Corp., Clarence, New York <> UUCP: {allegra|ames|boulder|decvax|rutgers|watmath}!sunybcs!kitty!larry <> VOICE: 716/688-1231 {att|hplabs|mtune|utzoo|uunet}!/ <> FAX: 716/741-9635 {G1,G2,G3 modes} "Have you hugged your cat today?"