This circuit was found in a 1977 documentation. With it we have the direct indication, through LEDs of an ASCII signal. The circuit must be powered by a voltage of 5 V.
This circuit is from 1987 documentation. The original project was carried out with the tape...
This traditional crystal radio circuit, but which has a modern version with diode, was found in an...
This VCA was found in the July 1988 issue of Radio Electronics magazine. It uses an OTA op amp and...