Morse Code Practice Oscillator
Morse Code Practice Oscillator
Additional Notes
The speaker (LS) can be any 8-ohm type up to 2-watts. C1 and C2 are ceramic capacitors. IC1 is a CMOS-TIMER, MC1455 or equivalent. And obviously, S1 is your Morse-keyer. To get a more precise duty-cycle replace the components within the dotted line from Fig. 1 with the ones in Fig. 2. The diode can be 1N4148 or equivalent. The zenerdiode is between 5.2 and 5.8 volt. Ra and Rb are experimental to suit your personal taste.
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