This electronic Morse key was found in a Popular Electronics from the 90's. The components are common, but there is a mechanical part that requires assembly skills.
This ultra-low distortion driver was found in 80's Analog Devices documentation. The circuit has a...
The output of this circuit can be coupled to a radio control transmitter to perform a...
This circuit trips when the voltage set in the pot is exceeded. The tone depends on C3 and...