This CW circuit was found in a Radio Amateur Today from the 890s. The CMOS circuit must be powered by an isolated source and has different dash and dot timings.
This circuit works with small 5 V incandescent lamps but can be modified to operate with LEDs. The...
Found in Linear Technology documentation from the 90s, this circuit uses an operational amplifier...
The tone produced by this circuit depends on the capacitor and the adjustment of the...