This circuit was found in a 1968 General Electric documentation. It has an input impedance of 2 M ohms and excites a load of 16 ohms. The integrated circuit of the time is the PA237.
This circuit is a variation of the common grid dip meter, having been found in a 1975 publication on FETs....
The FET of this circuit of a 1971 publication may be the BF245. The circuit serves as a voltage...
This configuration was found in old documentation and is valid for most general purpose NPN...