This circuit for analog VHF televisions was found in the 1989 Radio Electronics Experimenter magazine. It also works for FM receivers.
This small commercial radio for the MW band with germanium transistors was found in Japanese...
This alarm has a trip system with an LED on a keyring. The sensor is hidden by the glass or...
This circuit turns off when switch S1 is opened. The circuit is from the 1989 Radio Electronics...