An article in Radio Electronics magazine from November 1958 showed the construction of this tube audio oscillator. Note the use of lamps as a stabilizer to obtain better sinusoidal signals.
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,...