Path: utzoo!utgpu!watmath!att!dptg!rutgers!cs.utexas.edu!sun-barr!newstop!texsun!texbell!vector!telecom-gateway From: jjjs@cbnewsc.ATT.COM (james.j.sowa) Newsgroups: comp.dcom.telecom Subject: Re: DTMF frequencies Message-ID:Date: 8 Aug 89 12:39:40 GMT Sender: news@vector.Dallas.TX.US Reply-To: jjjs@cbnewsc.ATT.COM (james.j.sowa) Organization: AT&T Bell Laboratories Lines: 22 Approved: telecom-request@vector.dallas.tx.us X-Submissions-To: telecom@eecs.nwu.edu X-Administrivia-To: telecom-request@vector.dallas.tx.us X-TELECOM-Digest: volume 9, issue 281, message 8 of 10 >X-TELECOM-Digest: volume 9, issue 275, message 6 of 12 >What are the frequencies of the various tones used for DTMF? >Thanks, Here is the DTMF chart taken from "Notes on Distance Dialing" January 1975 HIGH-Group Frequencies (Hz) 1209 1336 1477 1633 687 1 2 3 A LOW GROUP FREQUENCIES 770 4 5 6 B (HZ) 852 7 8 9 C 941 * 0 # D ================================================================== Jim Sowa