This circuit is from 1967 General Electric documentation. It uses SUS which are not very common components today. The maximum frequency should not exceed a few kilohertz.
In the figure we have a simple signal tracer circuit to be coupled to the volume control of an AM...
This circuit was found in documentation from the 90s, using components from that time. The...
This circuit, obtained from old documentation, allows the recovery of sulfated batteries. The...