We found this circuit in a 1969 General Electric documentation. The circuit uses transistors of the time and the diodes in the dotted board must be mounted on the output transistor heatsinks.
This audio generator that produces both rectangular and sinusoidal signals was found in a...
This simple circuit for a high impedance magnetic phone (500 ohms or more) has been found in a...
Found in an American publication from 1968, this circuit can be made based on a TIP42 that must be...