1938 Two-Tube Shortwave Regen

1938FebPS11938FebPS2The February 1938 issue of Popular Science carried the plans for this two-tube regenerative shortwave receiver.  While absent from the schematic diagram, the globe on the top was critical, since it allowed the shortwave fan to quickly spot the location of every new station logged, and easily spot the location where the message originated.

The circuit inside the box employed two type 30 tubes, one serving as regenerative detector, with the other serving as AF amplifier. Since regeneration operated more smoothly at a reduced voltage, the set employed two B batteries. A 22.5 volt battery powered the detector, with a 45 volt battery allowing for extra volume from the amplifier stage.

The cover of the set was hinged, to allow for changing the plug-in coils.


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