Hysteresis compensator (CB7980E)

Suggested by a 90's Linear Databook, this circuit compensates for capacitor hysteresis. The main component is from the era.

Audio controlled switch (CB8435E)
Found in a 90s Popular Electronics, this circuit triggers a load from the audio signal applied to...
Logarithmic photometer (CB20722E)
The indicator for this circuit is a 0 to 1 mA milliammeter. The operational is from the 70s, when...
Optical isolator (CB8272E)
This sensor circuit from a 1967 Ferranti documentation uses components from the era. The circuit...