Found in Motorola's 1967 documentation this circuit can use any general-purpose transistor. The signal should be applied to a good amplifier. The noise diode can be replaced with a common one.
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...