This circuit is from a 2004 documentation serving for signals from 1 MHz to 160 MHz. The antenna is of the telescopic type and the analog instrument is of the type found in old sound equipment.
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...