This shortwave preselector was found in the July 1994 issue of Radio Electronics magazine. The circuit is suitable for telescopic antennas, matching the impedance with the receiver 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...