The October 1943 issue of Radio Craft carried this schematic for a one-tube AC-DC shortwave receiver. The circuit had been sent in by Leo Silber of Springfield, Mass., who reported that in 25 nights, he had pulled in over 200 stations from as far away as Little America, Antarctica.

The set used a 6C8G, with half the tube serving as rectifier and the other half as regenerative detector. Plug-in coils were used along with a variable capacitor for tuning. Silber reported that the set could drive either headphones or a small speaker.

For those wishing to duplicate the circuit, it appears that a 6SC7 can be substituted.  Those tubes are still rolling off the Russian assembly lines of Sovtek, and are available on Amazon.  For information on winding the plug-in coils, see our plug-in coils page, and for sourcing other parts, you can get ideas at our crystal set parts page.

If the circuit looks familiar, it’s because the magazine’s March 1943 issue had carried a slight variation on the same circuit, also sent in by Mr. Silber.  Silber, then a high school senior, was apparently not licensed before the War, but the 1949 call book shows him as holding W1NRP.  He went on to receive his Ph.D. in Physics from Purdue University, and later served as Professor of Electrophysics at the Polytechnic Institute of New York, Brooklyn.  A 1981 biography is available at this link.