This circuit is from Radio Electronics from March 1977. The integrated circuit is from that time and the circuit is intended for an infrared audio link. The modulation is in pulse frequency.
In the figure we have a circuit in which two moving bar/dot indicators are connected together to...
This simple unregulated half-wave font was found in old American documentation. The diode is...
This simple radio for listening to a headphone with two CK722 transistors was found in Radio...