TOUCH_TONE_IC

Published:2009/7/14 21:14:00 Author:May | From:SeekIC

MOSTEK MK5085/6 IC and keyboard together form inexpensive Touch-Tone generator producing tones within 0.75% of required values. Uses 3.579545-MHz TV color-burst crystal. Pin 15 is grounded to provide dual tones only .Pin 10 provides output when keyboard entry has been made ,for keying push-to-talk (PTT) Loudspeaker can be eliminated if output if fed directly into microphone input of transmitter. Choice of IC depends on type of keyboard used.-T. Ahrens, Integrated-Circuit Tone Generator, Ham Radio, Feb. 1977, p70.



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