Standing wave alarm (CB8986E)

This circuit triggers a warning LED when the standing waves reach a high value. The circuit was found in a 1980s documentation for radio amateurs.

Active Antenna (CB4750E)
This good gain antenna up to 30 MHz was found in an American 1990s documentation. The circuit can be...
Switch lighting (CB7965E)
This circuit keeps an LED on briefly when S1 is pressed. The time depends on C1. The circuit is...
Automatic Headlight Control 555 (CB25502E)
This circuit was found in the September 1992 issue of Radio Electronics magazine. The circuit does...