Using a common crystal diode and a 741, this circuit can be used to detect microwaves. The circuit is from old documentation and the switch selects the gains.
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...