1956 Zenith Royal 500, 7XT40Z1 chassis
Coat pocket radio, nylon cabinet
5 3/4 x 3 1/2 x 1 1/2 inches / 146 x 89 x 38 mm
Seven transistors (Zenith ovals, 121-15, 121-16, 2x 121-17, 121-18, 2x 121-19)
Superheterodyne circuit, hand-wired aluminum chassis
Four 1.5-volt AA cells
Manufactured by Zenith Radio Corp.; Chicago, Illinois
Zenith's first transistor radio — the unit shown here is the third chassis version (7XT40Z1) of the first Royal 500 model series, preceded by the 7XT40Z chassis, and before that the original 7XT40 chassis of the very first Zenith 500 version produced in 1955. All three versions had hand-wired chassis, unlike their successors which used pc-board chassis. And unlike their many successors, beginning with the 1957 7ZT40 chassis series, the first three Royal 500 versions lacked vernier tuning.
Along with the Regency TR-1, the Zenith Royal 500 is a US transistor radio that no one is about to forget anytime soon.