userDBUG@ualtamts.BITNET (Dan Berry) (08/13/89)
I was interested in finding out the tone plans for the typical phone system's call progress signals, but I can't seem to be able to find them in any of my books! You know, the frequencies for a dial tone, busy signal, ringing and the rest of them. From someone else that I've talked to, they made mention that only some four frequencies were used to get some 20+ signals. dB's and timing too, S.V.P. Would anyone out there happen to be able to help me, please? It's for a practical joke I want to play on a friend. If you could just Email me the listings, then I could compile them and summarize if anyone else would like... +-----------------------------------+ DAN BERRY ! "Violence is the last ! University of Alberta ! refuge of an incompetent." ! Computing Systems +-----------------------------------+ (Network and DataCom)
john@apple.com (John Higdon) (08/15/89)
In article <telecom-v09i0294m02@vector.dallas.tx.us>, userDBUG@ualtamts.BITNET (Dan Berry) writes: > I was interested in finding out the tone plans for the typical phone > system's call progress signals, but I can't seem to be able to find > them in any of my books! You know, the frequencies for a dial tone, > busy signal, ringing and the rest of them. From someone else that > I've talked to, they made mention that only some four frequencies > were used to get some 20+ signals. dB's and timing too, S.V.P. All of the information you seek in the Radio Engineer's Handbook. I don't have my copy at hand, but it's widely available and in it's umpteenth edition. Everything you ever wanted to know about telephony hardware is in that book. -- John Higdon | P. O. Box 7648 | +1 408 723 1395 john@zygot.uucp | San Jose, CA 95150 | M o o !