Found in 90s Radio Electronics, this circuit is intended for amplifying analog video signals. Integrated circuits are uncommon today and the bandwidth is 100 MHz.
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,...