Found in the 1975 RCA tube manual, this circuit appears elsewhere in this section. The circuit uses contemporary components and is powered by the power grid.
This is an old test circuit for integrated TTL counters, feeding a Nixie tube, common at the time....
This traditional crystal radio circuit, but which has a modern version with diode, was found in an...
This headphone amplifier using a pickup coil can be used as an extension for devices such as TVs,...