Featured in the February 1949 Radio Electronics magazine, this benchtop instrument generates multi-range audio signals. The circuit has 6 tubes including the rectifier.
This two-transistor emitter-coupled oscillator circuit with capacitive feedback was found in the...
This simple circuit produces sound effects given by the 4093 oscillators and switches LEDs...
This circuit uses two sensors that are placed at the intersection of a miniature railroad, causing the LED...