This receiver was found in a Popular Electronics from the 90's. Its different configuration shows a tuning circuit after the tube that works as an aperiodic amplifier. Observe supply voltages.
This circuit was found in an old documentation and can be powered by a solar panel. The touch...
This simple circuit can be used on both 110V and 220V mains. We find it in an 80's Electronic...
This circuit was found in a 1980s instrumentation publication and can be applied to virtually any...