What Happened to National? Its Atomic Clock Cost $50,000

National Company built the HRO on Sherman Street in Malden, Massachusetts. It went on sale in October 1934 at $233 without tubes, speaker or power supply, and within ten years, by most accounts, it was copying German traffic for Bletchley Park. You remember the PW dial: fifty divisions a turn, ten turns across the range, no backlash, and a station logged at three-twelve still sitting there the next night. You pulled the coil drawer to change bands and checked the chart for frequency. National was never behind; the HRO-500 went fully solid-state and synthesized in 1964. The clock was the bet. In October 1956 National showed the Atomichron, the first commercial atomic clock, at $50,000. About fifty sold, ninety percent to the military, after nearly a million in development, and the military contracts around it disappointed. In January 1971, 73 Magazine reported National in receivership. 73. #hamradio #amateurradio #boatanchor #shortwave #vintageradio #electronicshistory