TWO_TIMER_KEYER

Published:2009/7/11 4:00:00 Author:May | From:SeekIC

Characters are self-completing and fully adjustable as to speed and length of character. When dot key is closed, NE555 timer U1 becomes astable MVBR with speed determined by F1B and dot duration by RA Identical timer U2 provides longercharacter lengths for dashes. All diodes are 1N4004 or equivalent 400 V PIV at 1 A. Q1 and Q2 are 2N2222, Q3 is 2N5964, and RL1 is 12-V reed relay. Capacitor values are in microfarads. All pots are linear. Power is not regulated.-A.Ring, Build the World's Simplest Keyer, 73 Magazine, May 1977, p 46-47.



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