This detector with ultra-low deviation was found in an American documentation from the 90s. Operational amplifiers are from that time. The power supply must be symmetrical.
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...