This old circuit from a documentation from the 70s disconnects a TV from a signal obtained on the TV itself, detecting when the tuned channel goes out of the air.
This audio-driven relay was published in the July 1977 issue of Radio Electronics magazine. The...
This circuit can be used for signaling a panel with a common incandescent lamp. The lamp will...
This crystal oscillator is indicated for the calibration of IF steps of common radio receivers. The...