Found elsewhere in this section, but from other sources, this circuit is from a 1964 Electronic Design. The transistor is from the era and the power voltage depends on this component.
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...