We found this circuit in a 1969 General Electric documentation. The circuit uses transistors of the time and the diodes in the dotted board must be mounted on the output transistor heatsinks.
This is the circuit of a sensitive voltmeter using a difficult-to-obtain 5 uA full-scale...
The circuit is from the United States Hands-On Electronics magazine, February 1987 edition. The...
The circuit shown was suggested by Analog Devices (www.analog.com) in its Application Note AN-411...