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 circuit is from a 1968 publication. It uses germanium transistors from the time, having...
This circuit can be used as shield or to drive powerful loads from low current switches such as...
This is a 6-transistor transistor receiver manufactured in the 60s. The circuit is a...