Seventy-five years ago, this month’s issue of Popular Mechanics,
April 1941, carried the plans for this simple one-tube receiver, which covered the broadcast band, as well as the 160 and 80 meter bands.
Using a 1S4 Tube, the set required a B battery of only 6 volts, meaning that it could be run with four flashlight batteries in series. Another two flashlight batteries in parallel powered the filaments, and the total cost of batteries was only 30 cents.
Also presented was an audio amplifier on a separate chassis, also using a 1S4, which would drive a three inch speaker. Or, as the user in this drawing is shown, the set could be run by itself with headphones. Volume and regeneration were controlled by an adjustable tickler coil, keep the parts count of the set low.