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| Regency TR-1. |
A transistor radio is a small portable radio receiver that uses transistor-based circuitry. Following their development in 1954, made possible by the invention of the transistor in 1947, they became the most popular electronic communication device in history, with billions manufactured during the 1960s and 1970s. Their pocket size sparked a change in popular music listening habits, allowing people to listen to music anywhere they went.
Before the transistor was invented, radios used vacuum tubes. Although portable vacuum tube radios were produced, they were typically bulky and heavy. In the early 50s,though, models with tubes using one volt for the filament circuit and 67 volts for the plate circuit were produced. These were much smaller. Bell Laboratories demonstrated the first transistor on December 23, 1947. The scientific team at Bell Laboratories responsible for the solid-state amplifier included William Shockley, Walter Houser Brattain, and John Bardeen.
There are many claimants to the title of the first company to produce practical transistor radios, Texas Instruments had demonstrated all-transistor AM (amplitude modulation) radios as early as May 25, 1954, but their performance was well below that of equivalent vacuum tube models. A workable all-transistor radio was demonstrated in August 1953 at the Düsseldorf Radio Fair by the German firm Intermetall. It was built with four of Intermetall's hand-made transistors, based upon the 1948 invention of the "Transistron"-germanium point-contact transistor by Herbert Mataré and Heinrich Welker. However, as with the early Texas Instruments units (and others) only prototypes were ever built; it was never put into commercial production. RCA had demonstrated a prototype transistor radio as early as 1952, and it is likely that they and the other radio makers were planning transistor radios of their own, but Texas Instruments and Regency Division of I.D.E.A., were the first to offer a production model starting in October 1954.
The use of transistors instead of vacuum tubes as the amplifier elements meant that the device was much smaller, required far less power to operate than a tube radio, and was more shock-resistant. Two companies working together, Texas Instruments of Dallas, Texas and Industrial Development Engineering Associates (I.D.E.A.) of Indianapolis, Indiana, were behind the unveiling of the Regency TR-1, the world's first commercially produced transistor radio. Previously, Texas Instruments was producing instrumentation for the oil industry and locating devices for the U.S. Navy and I.D.E.A. built home television antenna boosters. The two companies worked together on the TR-1, looking to grow revenues for their respective companies by breaking into this new product area. In May 1954, Texas Instruments had designed and built a prototype and was looking for an established radio manufacturer to develop and market a radio using their transistors. (The Chief Project Engineer for the radio design at Texas Instruments' headquarters in Dallas, Texas was Paul D. Davis, Jr., who had a degree in Electrical Engineering from Southern Methodist University. He was assigned the project due to his experience with radio engineering in World War II.) None of the major radio makers including RCA, Philco, and Emerson were interested. The President of I.D.E.A. at the time, Ed Tudor, jumped at the opportunity to manufacture the TR-1, predicting sales of the transistor radios at "20 million radios in three years". The Regency TR-1 was announced on October 18, 1954 by the Regency Division of I.D.E.A., was put on sale in November 1954, and was the first practical transistor radio made in any significant numbers. Billboard reported in 1954 that "the radio has only four transistors. One acts as a combination mixer-oscillator, one as an audio amplifier, and two as intermediate-frequency amplifiers." One year after the release of the TR-1 sales approached the 100,000 mark. The look and size of the TR-1 was well received, but the reviews of the TR-1's performance were typically adverse. The Regency TR-1 is patented by Richard C. Koch, former Project Engineer of I.D.E.A.
Source :-
https://en.wikipedia.org/wiki/Transistor_radio and
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