Found in a 1967 General Electric documentation this circuit uses unijunction transistors that may be equivalent to those indicated. The number of stages can be modified.
This configuration found in GE documentation from the 90s, can also be seen elsewhere in this...
This low input impedance amplifier stage was found in a 1963 documentation. The circuit employs a...
We found this voltmeter in a 1977 Radio Shack documentation. The integrated circuit can be the...