This simple circuit is a continuity test that, in addition to testing resistors, can also test other components. Power is provided by batteries and the LED can be of any color.
This test consists of a simple Hartley oscillator using a transformer of the type found on older...
This circuit, from a 1985 documentation, produces several types of sound effects selected by the...
This 6-transistor receiver was manufactured in Japan in the 60s. The circuit is superheterodyne and has a 6V...