High impedance stage (CB20564E)

This high input impedance amplifier stage was found in a 1963 documentation. The transistor germanium of the time.

Optical isolator (CB8272E)
This sensor circuit from a 1967 Ferranti documentation uses components from the era. The circuit...
555 2-Range Relay Up to 10 Minutes (CB25535E)
This circuit was found in the November 1992 issue of Radio Electronics magazine. The circuit has...
10kHz Low Pass Filter (CB25713E)
This circuit eliminates hiss and other noise from audio sources by cutting frequencies above 10...