Newsgroups: sci.electronics Path: utzoo!henry From: henry@utzoo.uucp (Henry Spencer) Subject: Re: Modular Telephone Connector Message-ID: <1988Sep22.060244.3959@utzoo.uucp> Organization: U of Toronto Zoology References: <4063@enterprise.UUCP> <1988Sep16.171228.16442@utzoo.uucp> <14054@ninja.UUCP> <17723@glacier.STANFORD.EDU> Date: Thu, 22 Sep 88 06:02:44 GMT 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