Switched analog buffer (CB9315E)

This circuit was obtained from an application note from Analog Devices from the 90s. The components are from that time.

Decade Counter with Nixie Tube (CB20141E)
This is an old test circuit for integrated TTL counters, feeding a Nixie tube, common at the time....
Crystal Radio (CB14015E)
This traditional crystal radio circuit, but which has a modern version with diode, was found in an...
Headphone amplifier (CB23888E)
This headphone amplifier using a pickup coil can be used as an extension for devices such as TVs,...