IAMBIC MORSE KEYER


LINK TO IAMBIC KEYER CIRCUIT

This is the American "Accu-Keyer" design which appeared pg 362 of 1975 ARRL Radio Amateurs Handbook.
The only change I made from the original was to use an LM556 (dual timer);
one half being the oscillator (original used a cross-coupled multivibrator with discrete transistors) and the other half as a 1 KHz 'sidetone' oscillator driving a very small loudspeaker.