Tunnel diode simple noise generator (CB23705E)

This circuit was found in Radio Electronics magazine from November 1960. The circuit is powered by a photocell of the time.

Variable Gain Differential Amplifier (CB14119E)
This instrumentation circuit was obtained in the National Semiconductor's Linear Applications...
LM380 2.5 W amplifier (CB10900E)
The traditional circuit was taken from a French magazine Radio Plans that no longer exists but can...
Field Strength Meter for TV (CB22312E)
We found this circuit in an American transistor book from the 1960s. The transistor is made of...