Pocket Radio, circa 1925

This "Pocket Radio" contains one vacuum tube, is battery-operated -- and portable. It was advertised as a "travelers delight," weighing four pounds and measuring 12 inches long. The set received local broadcast stations and could be connected to an antenna to increase its power. Laughably large by today's standards of portability, in the mid-1920s, most consumer radios were table-top sized or larger.