Modulator Amplifier (V1574E)

This circuit is from a 1938 tube manual. Transformers are the critical components. Component values are given.

Noise Generator with the 741 (CB12176E)
This traditional configuration of a white noise generator that uses the junction of a transistor with a...
Code Switch (CB6536E)
We found this circuit in a Popular Electronics of the 80s. Used integrated circuits are uncommon...
High impedance stage (CB20564E)
This high input impedance amplifier stage was found in a 1963 documentation. The transistor...