This circuit with junction field effect transistors was found in documentation from the 1980s. The transistors can be MPF102 or BF245 and details of the coils are not given in the original.
We found this circuit in a 1976 documentation. The FET can be BF245 or MPF102 and the power supply...
This circuit was obtained in a transistors manufacturer's manual from the 90s. The circuit uses an...
The instrument of this field strength meter, from a 1970s publication, can be a 200 uA...