This 6-transistor radio was sold in Japan in the 1960s. The super-heterodyne circuit for the OM band was powered by ordinary batteries.
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...