This circuit, with printed circuit board, is from an article in Radio Electronics magazine from May 1971. The circuit uses the C106 which was already a common component at the time.
This circuit from a June 1957 Radio Electgronics is for oscilloscopes of the time with a maximum...
This simple receiver for listening on a crystal phone tunes the range of medium waves. The circuit...
This circuit in a receiver that allows the capture of distant stations with short waves. The...