BUY PRINT    Washington, D.C., circa 1924. "Brent Daniel, formerly of the Radio Laboratory of the Bureau of Standards at Washington, with the first portable Super-Heterodyne, his own design. The seven vacuum tubes, batteries, loop antenna, loudspeaker and other necessary units are completely self-contained in the carrying case. He has been able to hear Pacific Coast stations from this outfit." | Click image for Comments. | Home