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Path: utzoo!watmath!clyde!burl!ulysses!mhuxj!ihnp4!zehntel!dual!paul
From: paul@dual.UUCP (Baker)
Newsgroups: net.ham-radio
Subject: Re: real meaning of DTMF
Message-ID: <856@dual.UUCP>
Date: Fri, 26-Oct-84 17:01:06 EST
Article-I.D.: dual.856
Posted: Fri Oct 26 17:01:06 1984
Date-Received: Sun, 28-Oct-84 05:51:04 EST
References: <973@hplabs.UUCP> <5415@brl-tgr.ARPA>
Organization: Dual Systems, Berkeley, CA
Lines: 20


>       I thought DTMF meant 'Dual Tone Multi-Frequency'. Contrary to
>   popular usage, TOUCH-TONE and DTMF are not the same.  TOUCH-TONE is
>   what the keypad on your telephone produces. DTMF is used for sending 
>   call information from one central office to another.
  
>       By the way, the tones used for DTMF are not the same as the tones
>   generated by your telephone pad.

I'm afraid the above just isn't true.  DTMF is the same as Touch-Tone (tm).
Look, for example at the EIA specification RS-470 describing Telephones.
It specifically states DTMF and gives frequencies.

The signalling method subject to being fooled by "Blue-boxes" is known
as MF.  The publication which gave out the MF frequencies was apparently
hastily removed as soon as the implications were realized.  These
frequencies are not produced by the DTMF or Touch-Tone (tm) pad in ones
telephone and certainly not by a dial phone !

Paul Wilcox-Baker.