This servo circuit was found in 1969 Motorola documentation. Integrated circuits and transistors are types of the time, hard to find today.
The JFETs of this old circuit admit modern equivalents and their characteristics determine the maximum...
This low power audio amplifier was found at 1992s Popular Electronics. Transistors are general...
This circuit transmits in the FM band. It is a good range FM transmitter found in a 90's Silicon...