The objective of the project is to decode dual tone codes into digits which are later interpreted by microcontroller. This device is very useful for decoding Dual Tone Multi Frequency (DTMF) generated ...

Winston-Salem, NC&#8212CML Microcircuits' CMX867A, a V.22 multi-standard modem IC for telephone-based information systems, includes an enhanced DTMF decoder, thus affording a more compact design and ...

Though many of us will never have experimented with it, most readers should be familiar with DTMF as the tones used by the telephone system for dialling. If your youth was not misspent mashing 4-4-2-6 ...

For a hobby that’s ostensibly all about reaching out to touch someone, ham radio can often be a lonely activity. Lots of hams build and experiment with radio gear much more than they’re actually on ...