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 is a four-quadrant multiplier using an LM3900. The circuit was found in the July 1988...
We found this circuit in the June 1992 issue of Radio Electronics magazine. The sensor is a common...
This simple circuit is powered by the logic circuit itself. Components are still common, although...