The configuration shown allows to obtain a high voltage gain for FETs. FETs can be BF245 or MPF102. The circuit is from the 1977 National Semiconductor FET Databook.
This simple circuit for a high impedance magnetic phone (500 ohms or more) has been found in a...
This 3 V rail to rail buffer was found in a National Semiconductor documentation. The gain is unit....
We found this circuit in the September 1971 issue of Radio Electronics magazine. The sensor is an...