Found in a 90s Popular Electronics, this circuit is interspersed between the filter and the oscilloscope input for analysis.
This circuit was found in old documentation. It can be made based on modern components. The time...
This small two-transistor AM radio was sold in the 1960s in Japan. The circuit was powered by two...
I found this circuit in an old English magazine from 1979, but it can be easily assembled with...