This pocket-sized VHF receiver was found in Radio Electronics magazine from January 1961. It uses a transistor and tunes to the 11-meter band, considered VHF at the time.
This circuit was found in an American documentation from the 90s. It can be implemented with...
This 2-terminal regulator was obtained from a 1990s National Semiconductor manual. The components admit...
This circuit uses a photocell as sensor and a sensitive relay according the power supply voltage....