This untuned (aperiodic) amplifier circuit was found in the August 1974 Radio Electronics magazine. The transistors are period, and the board layout is critical.
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...