Found in a 1966 Electronics World, this circuit applies to the protection of any analog instrument. The diodes can be of any general-purpose type.
This sensitive AM radio doesn’t need external antenna, picking easily local stations. The output...
This small FM transmitter circuit, using only common transistors, includes a mixer that allows it to be...
This circuit is from an old RCA MOSFET manual from the 70s. The circuit can be implemented with...