This circuit for receivers was found in an American documentation from the 90's. The circuit operates at up to 500 MHz. The integrated circuit used is uncommon nowadays.
This circuit is from a Radio Electronics magazine from July 1984. The transistor determines the...
This circuit was found at Electronics Now. It can be used as a shield detector for dial signals in an...
This circuit was obtained from an English circuit manual. Components are common and LEDs can be 3...