Amrad Corporation

Amrad was short for American Radio and Research Corporation, founded in the Medford Hillside area of Massachusetts in 1915 by Harold J. Power with financial backing from J. P. Morgan Jr. A Tufts University alumnus, Power organized a laboratory, radio tower and later equipment production on the hillside near campus. The company arose before the mass market for receivers: it tested radio links, built professional and military equipment and operated an experimental station. In March 1916 Power transmitted a radiotelephone concert from Medford to J. P. Morgan Jr. aboard the steamship Philadelphia, demonstrating voice and music by radio well before ordinary commercial programming. The station, known as 1XE and from 1922 as WGI, broadcast regular programs while US broadcasting was still taking shape. In Amrad's story, factory and antenna belonged to the same research setting.

After the First World War the company sought civilian demand for the capacity built up through military orders. It offered components, crystal receivers and valve sets, including modular designs for enthusiasts. Competition and patents shaped its technical choices: Amrad entered the Neutrodyne licensing system and tried to broaden its receiver range, but rapid changes in circuits and public taste made a competitive catalog hard to sustain. Meanwhile its Medford Hillside plant, also listed at 205 College Avenue, became a recognizable center of production.

The most unusual tube associated with Amrad was not intended to receive radio signals. Engineer Charles Grover Smith developed the gas-filled 'S' rectifier tube, without a heated filament: its task was to convert alternating current into high-voltage direct current for the anode supply of small transmitters. The S3000 was commercially offered in 1922; two tubes could provide the anode current needed by several low-power transmitting valves. The family also included types such as S4000 and S5000, with differently shaped envelopes and Edison screw bases. The absence of a filament was promoted as an advantage because it eliminated the heater supply, but it did not make the tube an alternative to ordinary receiver amplifier valves: it was a power-supply component for transmitting installations. Smith's work and the related patents subsequently influenced Raytheon's emerging rectifier business.

The company's history should be distinguished from the commercial life of its brand. American Radio and Research Corporation entered receivership in 1925; in December of that year Crosley purchased Amrad's assets and plant, along with technical rights useful to its own range. The Amrad name continued to appear on receivers during the Crosley period, but it did not always denote the same independent company founded by Power. This Massachusetts company should also not be confused with similarly named European businesses: its site, the 1XE/WGI station and the 'S' rectifier belong to the American history of Medford Hillside.