This oscillator was found in a 70s RCA linear circuit manual. The oscillator makes use of an integrated device from the time, difficult to find today.
This circuit can be used to recognize a tone by its frequency. When this tone is present in a...
Found in a 1980s documentation, this amplifier uses an operational aplifier of the time with two...
This circuit, from a publication of the 1970s, can compare the intensity of two light sources,...