transistor radio

This article is about an electronic device. For the fourth studio album by M. Ward, see Transistor Radio.

Regency TR-1.

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A transistor radio is a small transistor-based radio receiver.

History

Bell Laboratories demonstrated the first transistor on December 23, 1947. After obtaining patent protection, the company held a news conference on June 30, 1948, at which a prototype transistor radio was demonstrated. There are many claimants to the title of the first company to produce practical transistor radios, often incorrectly attributed to Sony (originally Tokyo Tsushin Kogyo). Texas Instruments had demonstrated all-transistor AM (amplitude modulation) radios as early as 1952, 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 Herbert Mataré and Heinrich Welker. However, as with the early Texas units (and others) only prototypes were ever built; it was never put into commercial production.

Texas Instruments was behind the Regency transistor radio. In May 1954, they had designed and built a prototype and were looking for an established radio manufacturer to develop and market a radio using their transistors. None of the major radio makers were interested.

The Regency TR-1, announced on October 18, 1954 by the Regency Division of I.D.E.A (Industrial Development Engineering Associates of Indianapolis, Indiana) and put on sale in November 1954 was the first practical transistor radio made in any significant numbers. Patented by Richard C. Koch, US patent 2892931, an employee of the company. It cost $49.95 (roughly $364 in 2006 USD) and sold about 150,000 units. Raytheon and Zenith Electronics transistor radios soon followed and were priced even higher. Even the first Japanese imports (in 1957) were priced at $30 and above. Transistor radios did not achieve mass popularity until the early 1960s when prices of some models fell below $20 ($140 in 2009 USD), then below $10 as markets became flooded with radios from Hong Kong by the mid to late 1960s.

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 were the first to offer a production model. Sony, at the time still a small company named Tokyo Tsushin Kogyo, Ltd., (aka "Totsuko"), followed soon after introducing their own five-transistor radio, the TR-55, in August 1955, under the new brand name Sony^[1]. With its release, Sony also became the first company to manufacture a radio from the transistors on up, and to utilize all miniature components.

Sony's first official import to the U.S.A. was the "pocketable"^[2] TR-63 released in March 1957^[3], a model which proved highly successful in that market. (The term "pocketable" was a matter of some interpretation, as Sony allegedly had special shirts made with oversized pockets for their salesmen^[4]). In January 1958, the company changed its name to Sony^[5], adopting the name that had previously been the reserve of its radio brand. The Sony TR-610 was released some months later, marking another resounding success and taking its place as the first transistor radio to sell more than a half-million units.

Sanyo 8S-P3.

The use of transistors instead of vacuum tubes as the amplifier elements meant that the device was much smaller and required far less power to operate than a tube radio. It also allowed 'instant on', since there were no filaments to heat up. The typical portable tube radio of the fifties was about the size and weight of a lunchbox, and contained several heavy (and non-rechargeable) batteries: one or more so-called "A" batteries to heat the tube filaments and a large 45- to 90-volt "B" battery to power the signal circuits. By comparison, the "transistor" could fit in a pocket and weighed half a pound or less and was powered by standard flashlight batteries or a single compact 9-volt battery. (The now-familiar 9-volt battery was introduced for powering transistor radios.)

Listeners sometimes held an entire transistor radio directly against the side of the head, with the speaker against the ear, to minimize the "tinny" sound caused by the high resonant frequency of its small speaker enclosure. Most radios included earphone jacks and came with single earphones that provided only mediocre-quality sound reproduction due to the bandwidth limitation of AM (up to 4500Hz). To consumers familiar with the earphone-listening experience of the transistor radio, the first Sony Walkman cassette player, with a pair of high-fidelity stereo earphones, would provide a greatly contrasting display of audio fidelity.

A modern transistor radio (Sony Walkman SRF-S84 transistor radio, released 2001, without included earphones)

The transistor radio remains the single most popular communications device in existence. Some estimates suggest that there are at least seven billion of them in existence, almost all tunable to the common AM band, and an increasingly high percentage of those also tunable to the FM band. Some receive shortwave broadcasts as well. Most operate on battery power. They have become small and cheap due to improved electronics which has the ability to pack millions of transistors on one integrated circuit or chip. The prefix "transistor" means a pocket radio; it can be used to refer to any small radio, but the term itself is now obsolete, since virtually all commercial broadcast receivers, pocket-sized or not, are now transistor-based.

Rise of digital audio player

Use of air signal only radios (AM/FM) have declined in popularity with the rise of portable digital audio players, which allow people to carry and listen to the music of their choosing and may also include a digital radio tuner. This is a popular choice with listeners who are dissatisfied with terrestrial music radio because of a limited selection of music or other criticisms. However, transistor radios are still popular for news, weather, live sporting events and emergency alert applications.

See also

Radio portal

• Broadcasting

References

Further reading

• Michael F. Wolff: "The secret six-month project. Why Texas Instruments decided to put the first transistor radio on the market by Christmas 1954 and how it was accomplished." IEEE Spectrum, December 1985, pages 64-69
• Transistor Radios: 1954-1968 (Schiffer Book for Collectors) by Norman R. Smith
• Made in Japan: Transistor Radios of the 1950s and 1960s by Handy, Erbe, Blackham, Antonier (1993) (ISBN 0-8118-0271-X)
• Unique books on Transistor Radios by Eric Wrobbel
• The Portable Radio in American Life by University of Arizona Professor Michael Brian Schiffer, Ph.D. (The University of Arizona Press, 1991).
• Restoring Pocket Radios (DVD) by Ron Mansfield and Eric Wrobbel. (ChildhoodRadios.com, 2002).
• The Regency TR-1 story, based on an interview with Regency co-founder, John Pies (partner with Joe Weaver) www.regencytr1.com/Regency_Early_Years.html

External links

• http://www.jamesbutters.com/ Focusing on the history and design elements of early pocket transistor radios.
• http://www.pbs.org/transistor/materials/how-europe-missed-transistor.pdfPDF
• TI Information Bulletin First Commercial Transistor Radio October 18, 1954
• Website about the first transistor radio by Dr. Steven Reyer, a Professor in the Electrical Engineering and Computer Science Department at the Milwaukee School of Engineering.
• M31 Galaxy of Transistor Radios Transistor radio site with photos and info on classic transistor radios from the US, Japan, and Europe.
• Radio Wallah Historical data accompanied by hundreds of images covering early transistor radios.
• Sarah's Transistor Radios Extensive website displaying over 1500 transistor radios and other information.
• Regency TR-1 Transistor Radio History: website with many historical references on the web and in published literature
• 1954 to 2004, the TR-1's Golden Anniversary. In depth coverage of the Regency radio.