When it comes to one tube radios, they don’t get much simpler than this one, which appeared 80 years ago in the January 1945 issue of Radio Craft. It had been sent in to the magazine by one Philip Dennison of Salina, Kansas, who noted that it worked as well as much larger radios.  It’s essentially a crystal set, with the crystal replaced by a tube with the grid and plate tied together to act as a diode.  The only power is the filament voltage, and the author reports that it works even better with the battery slightly run down.

It’s likely that the author was this Philip Dennison, who was born in 1926 and died in 1964,  Since his grave indicates that he was a World War II veteran, I’m guessing that he was drafted shortly before his circuit was published at the age of 18.