The FET for this circuit from a 1977 documentation can be BF245 or MPF102. The circuit measures impedances indicated by an instrument. The frequencies normally used in the test are between 400 and 500 Hz.
The FET for this circuit from a 1977 documentation can be BF245 or MPF102. The circuit measures impedances indicated by an instrument. The frequencies normally used in the test are between 400 and 500 Hz.