This simple circuit was found in a Japanese magazine in 1967. The circuit is listening on a headset and the coil is 50 + 50 turns of wire 28 or thinner on a ferrite rod.
This circuit is from an old documentation of Radio Shack from the 70s. The transistor should...
This 1980s circuit was found in Motorola documentation. The circuit uses period components that admit of...
The power supply shown in the figure provides output voltages in the range of 1.2 to 25 V with...