Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!uwm.edu!linac!att!pacbell.com!lll-winken!telecom-request From: wb8foz@mthvax.cs.miami.edu (David Lesher) Newsgroups: comp.dcom.telecom Subject: Even More on Selective Ringing Message-ID: Date: 26 Mar 91 23:08:54 GMT Sender: Telecom@eecs.nwu.edu Reply-To: David Lesher Organization: NRK Clinic for habitual NetNews abusers Lines: 49 Approved: Telecom@eecs.nwu.edu X-Submissions-To: telecom@eecs.nwu.edu X-Administrivia-To: telecom-request@eecs.nwu.edu X-Telecom-Digest: Volume 11, Issue 245, Message 4 of 8 {likely more than you even wanted to know;-} Well, I dug out a ten + year old North Supply book, and here's what I found. There were lots choices in ringers, all basically with this scheme: Untuned: Straight Line 5900 ohms Straight Line 1000/2650 ohms Tuned: Harmonic: 16.66 hz 25.00 33.33 50.00 66.66 Decimonic: 20.00 30.00 40.00 50.00 60.00 Synchromonic: 30.00 42.00 54.00 66.00 {whew..} A few thoughts/questions: Who used what scheme? I sure would not want to be the poor guy with the 60 hz assignment - I'd expect a problem with falsing. There's no mention of 'tuning' these with different caps. There was a different listing that did enumerate capacitors of different values, but it was not clear that one could retune a ringer; rather it appeared that ringer X needed cap x, Y needed y etc. But I'm likely reading between the lines too much. So there were {at least} the following selective ringing methods: Bell 2 party {ring to ground, tip to ground} Bell 4 party {above, plus superimposed DC block/pass} Harmonic Decimonic Synchromonic 3 longs and a short [Hey, that's us!] wb8foz@mthvax.cs.miami.edu (305) 255-RTFM