This circuit was found in a documentation from 1948. There are 5 valves with push-pull output. The source uses a transformer, and the indicated application is with turntables.
This circuit using only transistors was obtained from Ferranti's 1969 documentation. It can be...
This sensitive circuit can be designed with FETs such as BF245 and MPF102. The sensor is a silicon...
Found in Popular Electronics from the 90s, this circuit generates two tones that are selected by a...