rick@cs.utexas.edu (Rick Watson) (08/04/89)
What are the frequencies of the various tones used for DTMF? Thanks, Rick Watson University of Texas Computation Center arpa: watson@utadnx.cc.utexas.edu (128.83.1.26) uucp: ...cs.utexas.edu!ut-emx!rick bitnet: watson@utadnx span: utspan::watson (UTSPAN is 25.128) phone: 512/471-8220 512/471-3241
morris@jade.jpl.nasa.gov (Mike Morris) (08/07/89)
(Rick Watson) writes: > >What are the frequencies of the various tones used for DTMF? > 1209 1336 1477 1633 697 1 2 3 A FO 770 4 5 6 B F 852 7 8 9 C I 941 * 0 # A D P I have an old 5-line 4-wire Autovon phone here that I modified (added a network) for 25-pair 2-wire use. It has a "A" on the key that would normally be a "#". The 4th column keys are labeled with FO-F-I-P. On another Tiwanese throw-away phone I've seen the same keys labeled A-B-C-D, this phone was sold at the local K-Mart and the extra buttons were explained as "4 additional keypad keys for future banking and special services". A long time ago I figured out the mathematical sequence that the frequencies follow - Without overlapping the groups I figured that you could get a 9 by 9 matrix, with overlap a 12 by 9 (my memory is hazy, this would have been in 1969 or 1970). Note that these are not "MultiFreq" tones. Mike Morris UUCP: Morris@Jade.JPL.NASA.gov #Include quote.cute.standard | The opinions above probably do not even come cat flames.all > /dev/null | close to those of my employer(s), if any.
jjjs@cbnewsc.ATT.COM (james.j.sowa) (08/08/89)
>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
deej@bellcore.bellcore.com (David Lewis) (08/10/89)
In article <telecom-v09i0275m06@vector.dallas.tx.us>, ut-emx!rick@cs.utexas.edu (Rick Watson) writes: > What are the frequencies of the various tones used for DTMF? High Group (Hz) 1209 1336 1477 1633 Low 697 1 2 3 A Group 770 4 5 6 B (Hz) 852 7 8 9 C 941 * 0 # D A,B,C,D are not currently implemented anywhere, so far as I'm aware. (Courtesy of, of coures, Notes on the BOC Intra-LATA Networks, 1986...) -- David G Lewis ...!bellcore!nvuxr!deej "If this is paradise, I wish I had a lawnmower."