This circuit works as both an injector and a signal follower. We found it in the May 1994 issue of Electronics Now. The Z1 headphone must be high impedance.
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...