The story of the Zenith Radio Corporation
Shortwave radio
A Zenith Model 5-S-220 "cube" radio circa 1937.
Among Zenith's early famous products were the 'Royal' series of
transistor radios and the 'Trans-Oceanic' series of shortwave portable
radios, which were produced from 1942 to 1981.
http://www.myantiqueradio.com/zenith/Zenith_Story.pdf