Eighty years ago, the January 1938 issue of Shortwave and Television magazine carried the plans for this two-tube regenerative shortwave receiver.  With plug-in coils, the set would cover 550 through 9 meters. The set used two 1.5 volt tubes: The RK42 triode served as regenerative detector, and a dual RK43 provided two stages of audio amplification.

The set was capable of pulling in stations from around the world, and “there is practically no limit to which this receiver will cover. So long as general receiving conditions are favorable, this little set will work wonders.”

The use of two variable capacitors allowed for bandspread tuning, and a variable resistor was used for regeneration.