Found in an American documentation from the 90s, this circuit has a configuration that has been extensively explored in other articles on this site. The FET can be the MPF102 or equivalent.
This circuit was published in an Italian magazine Radio Elettronica in February 1976. The...
Found in a Popular Electronics from the 90's, this circuit converts a 40 V symmetrical source to a 5...
This high selectivity circuit for single tone decoding was found in 1970s documentation. The coil...