This constant current source for high voltage loads was obtained from a 1967 General Electric documentation. The components are of the time, but allow equivalents.
Found in a Maxim documentation from the 90s, this circuit produces a voltage of 5 V from an input...
This 1-transistor reflex receiver was found in a 1963 publication. The coil is for the mid wave...
We found this audio preamplifier circuit with a 741 operational in a 1976 publication. However,...