We found this circuit in a 1968 Electronics World. The transistors are from the era and information about the transformer was included. Transistors support current equivalents.
This circuit uses a JFET at the input to increase the impedance, and is temperature compensated...
Using L144 operational, this circuit applies to other equivalent operational. The circuit is from...
Suggested by General Electric in 1967 documentation this circuit uses an isolation transformer to...