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Raytheon Radio Tube Type 6J7G, by Raytheon, USA, Mid 20th Century

Inventory Number: 39208

Number of documents: 2

Document Type: Miscellaneous Note

Document Heading: Technical Details


Type 6J7G was contemporary of the 'Magic Three' and almost as ubiquitous. The 'Magic Three' were valves 6K7, 6K8 and 6Q7: a set of valves that defined the international 'standard' low-cost superhet from the late 1930s until the end of valve domestic radio. Although originally designed as a detector its linear characteristic and good internal shielding made it natural choice for audio. For two decades, it was international standard valve for audio amplifier input stages and audio systems generally. The Mullard-Philips type EF37A, for many years the standard British low-noise audio pentode, was really 6J7G under another name.

Document Type: Miscellaneous Note

Document Heading: Manufacturer Details


Raytheon was founded in Cambridge, Massachusetts in 1922 by Laurence K. Marshall, Vannevar Bush and Charles G. Smith, with the original intention of selling artificial coolants for home refrigerators. This failed and they instead decided to develop a new kind of gaseous tube that would allow radios for the first time to be plugged into a wall socket and operate on electricity rather than batteries. By 1925, they had succeeded and marketed this 'gaseous rectifier' under the name of Raytheon ('Ray' coming from 'rai', Old French for 'a beam of light', and 'theon' being Greek for 'from the gods'. By 1926, the company had made $1 million and was well on the road to success. The company still exists today as defence technology company still based in Massachusetts but now with over 80,000 employees worldwide and an annual revenue of over $80 billion.

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