We found this circuit in the October 1994 issue of Electronics Now magazine. The circuit uses a now-uncommon 4046 PLL and the gates of a CMOS 4001.
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...