Found in a 1967 Electronic Design, this circuit changes the phase of a signal in 8 different ways, given by the formulas next to the diagram. Equivalent general-purpose transistors can be used.
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...