This is a diagram of a 1970s reel or tape recorder. It is an Italian Geloso recorder, quite popular at the time. The circuit is a reference for equipment recovery.
Any JFET can be used in this circuit suggested by Electronics Now magazine, April 1993. The...
This circuit allows you to view two low frequency signals on a single channel oscilloscope. It was...
Found in an old Popular Electronics this circuit is still current. The SCR can be of the 106...