This configuration is from the 70s, having been found in an American documentation. The transistors can be BC549 for Q1 and BC548 for Q2.
This circuit triggers an alarm when the mains power is cut off. The circuit was found in the July...
This acutely tuned circuit was found in American documentation from the 1960s. The transistors are germanium...
This small AM transmitter was found in American documentation from the 1980s. Transistor support...