Instruct: Given a question, retrieve relevant documents that can help answer the question.
Query: When was the transistor radio invented?
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[1] 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. Beginning in the 1980s, however, cheap AM transistor radios were superseded by devices with higher audio quality such as portable CD players, personal audio players, boomboxes, and (eventually) smartphones,[2] some of which contain radios themselves.[3]
Vacuum tubes remained the preferred amplifying device for 40 years, until researchers working for William Shockley at Bell Labs invented the transistor in 1947. In the following years, transistors made small portable radios, or transistor radios, possible as well as allowing more powerful mainframe computers to be built. Transistors were smaller and required lower voltages than vacuum tubes to work.
For its first fifty years the phonograph turntable did not use electronics; the needle and soundhorn were purely mechanical technologies. However, in the 1920s radio broadcasting became the basis of mass production of radio receivers. The vacuum tubes that had made radios practical were used with record players as well, to amplify the sound so that it could be played through a loudspeaker. Television was soon invented, but remained insignificant in the consumer market until the 1950s. The transistor, invented in 1947 by Bell Laboratories, led to significant research in the field of solid-state semiconductors in the early 1950s. The transistor's advantages revolutionized that industry along with other electronics. By 1959 Fairchild Semiconductor had introduced the first planar transistor from which come the origins of Moore's law. Integrated circuits followed when manufacturers built circuits (usually for military purposes) on a single substrate using electrical connections between circuits within the chip itself. Bell's invention of the transistor and the development of semiconductors led to far better and cheaper consumer electronics, such as transistor radios, televisions, and by the 1980s, affordable video game consoles and personal computers that regular middle-class families could buy.
Prior to the Regency TR-1, transistors were difficult to produce. Only one in five transistors that were produced worked as expected (only a 20% yield) and as a result the price remained extremely high.[12] When it was released in 1954, the Regency TR-1 cost $49.95 (equivalent to $466 today) and sold about 150,000 units. Raytheon and Zenith Electronics transistor radios soon followed and were priced even higher. In 1955, Raytheon's 8-TR-1 was priced at $80 (equivalent to $748 today).[12] By November 1956 a transistor radio small enough to wear on the wrist and a claimed battery life of 100 hours cost $29.95.[20] Sony's TR-63, released in December 1957 cost $39.95 (equivalent to $357 today).[12] Following the success of the TR-63 Sony continued to make their transistor radios smaller. Because of the extremely low labor costs in Japan, Japanese transistor radios began selling for as low as $25. In 1962 American manufacturers dropped prices of transistor radios to as low as $15 (equivalent to $124 today).[12]
The invention of the transistor made it possible to produce very small portable radios that did not need a warm-up time, and ran on much smaller batteries. They were convenient, though the prices were initially high and the sound quality of early models was not nearly as good as tube radios. Later models equalled or surpassed tube models in audio quality. Transistors also made it possible to manufacture portable FM radios, which was impractical using tubes. 
Turner was involved with creating the 1N34A germanium diode at Sylvania in the 1940s. He began experimenting with germanium transistors soon after their invention in 1947. In 1949, before transistors were commercially available, he published the popular article "Build a Transistor", considered a "benchmark publication" in amateur radio. In January 1950, after commercial units were released, he published "A Crystal Receiver with Transistor Amplifier" in "Radio and Television News", along with plans for a three-transistor radio circuit. These plans – printed four years before the Regency TR-1 (the first commercial transistor radio) – were the first time most amateur radio operators were introduced to transistors as viable radio components. He continued development of his pocket-size radios as superior transistors became available, culminating in the 'widely read' "Transistor Portable with a "Punch"", an 'ambitious' four-transistor non-superheterodyne AM radio published in "Popular Electronics" in 1956.
He began as an engineer at Raytheon when he was hired in 1933 during his junior year at MIT for 50 cents an hour. His first success was in the development of subminiature tubes, in the Special Tubes group. While working in the special tube division, before the outbreak of WW2, he wanted to use subminiature tubes in consumer products (hearing aids and radios). After Raytheon's success in subminiature tubes for wartime applications such as the proximity fuze, Raytheon became the leader in the design and production of subminiature tubes. Raytheon promoted Krim to be head of the Special Tube Division. The proximity fuze was a small radar-like device attached to on a bomb or artillery shell that would detonate the bomb or shell before impact, causing a greater destruction. Just as importantly, the fuze initiated detonation *without* needing to impact the target directly, or to rely on an altitude setting in the fuze that would detonate the shell at an estimated target height, and close enough that the shrapnel cloud would impact the target. Given the extremes of aircraft target range and speed, and of shell accuracy of the day, the proximity fuze dramatically increased the effectiveness of anti-aircraft fire. After World War Two ended, Norman Krim got the go ahead from Laurence Marshall head of Raytheon, to build the first pocket portable tube radio using and adapting subminiature tubes for commercial products. The radio was called the Belmont Boulevard designed by Niles Gowell (Raytheon had acquired Belmont Radio Corp for this purpose).
Although the Belmont Boulevard did not sell well, he later was given another challenge by Laurence Marshall the head of Raytheon to start making semiconductor products. Under his direction Raytheon became a leader in making hearing aid transistors. A Time Magazine article in 1953 stated, "“This little device, a single speck of germanium, is smaller than a paper clip and works perfectly at one-tenth the power needed by the smallest vacuum tube. Today, much of Raytheon’s transistor output goes to America’s hearing aid industry.”" The hearing aid was first mass-produced consumer electronics to be miniaturized. By 1948 Raytheon had 98% of the hearing aid tube market. Because of the invention transistor by Bell Labs in 1948, Raytheon, under Krim's direction started making transistors for hearing aids. Their first transistor product was the CK703 point contact transistor. His successes in Raytheon's Semiconductor Products allowed him to become Vice President of Receiving, Cathode Ray Tubes and Semiconductor Division.
He is particularly known for developing the first mass-production alloy junction transistor and used the fallouts or transistors that did not meet specifications as transistors to be sold at a much lower cost, the CK721 and CK722. Raytheon quickly moved into alloy junction transistor because of the lower noise, more rugged and lend it self to mass production, compared to point contact transistor. Establishing a tradition that would become a distinctive feature of early transistors, these (CK722) were production drop-outs from another transistor line, the CK721, that did not pass test criteria for the CK718 hearing aid transistor (the main product). However they could be sold at a much lower cost as a lower specification product. This concept help start a new market for transistors, the experimenter and hobby line. Seeing this window of opportunity Krim linked up with Radio Shack to market the hobby grade transistors. Other manufacturers followed soon after.
Prominent assassinations, targeted killings, and assassination attempts include:The recently invented transistor, though initially quite feeble, had clear potential and was rapidly improved and developed at the beginning of the 1950s by companies such as GE, RCA, and Philco. The first commercial transistor production started at the Western Electric plant in Allentown, Pennsylvania, in October, 1951 with the point contact germanium transistor. It wasn't until around 1954 that transistor products began to achieve real commercial success with small portable radios.
Early transistorized radios and other equipment needed a suitable voltage miniature battery. Early transistor radios required a  volt battery. Although the transistors would theoretically operate from lower voltages, in 1954, the point contact transistors had to be operated very close to their V limit in order to get the required frequency response. However, a suitable miniature battery was already marketed for (vacuum tube) hearing aids. As transistors rapidly improved, particularly when alloy transistors were introduced, radios were able operate from lower voltages and the battery manufacturers introduced suitable batteries as the demand arose. 
Shockley, angered by not being included on the patent applications, secretly continued his own work to build a different sort of transistor based on junctions instead of point contacts; he expected this kind of design would be more likely to be commercially viable. The point contact transistor, he believed, would prove to be fragile and difficult to manufacture. Shockley was also dissatisfied with certain parts of the explanation for how the point contact transistor worked and conceived of the possibility of minority carrier injection. On February 13, 1948 another team member, John N. Shive, built a point contact transistor with bronze contacts on the front and back of thin wedge of germanium, proving that holes could diffuse through bulk germanium and not just along the surface as previously thought. Shive's invention sparked Shockley's invention of the junction transistor. A few months later he invented an entirely new, considerably more robust, type of transistor with a layer or 'sandwich' structure. This structure went on to be used for the vast majority of all transistors into the 1960s, and evolved into the bipolar junction transistor. Shockley later admitted that the workings of the team were "mixture of cooperation and competition." He also admitted that he kept some of his own work secret until his "hand was forced" by Shive's 1948 advance. Shockley worked out a rather complete description of what he called the "sandwich" transistor, and a first proof of principle was obtained on April 7, 1949.
There are numerous claimants to the title of the first company to produce practical transistor radios. Texas Instruments had demonstrated all-transistor AM radios as early as 1952, but their performance was well below that of equivalent battery 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.
Listening habits changed in the 1960s due to the introduction of the revolutionary transistor radio, which made possible by the invention of the transistor in 1946. Their compact size — small enough to fit in a shirt pocket — and lower power requirements, compared to vacuum tubes, meant that for the first time radio receivers were readily portable. The transistor radio became the most widely used communication device in history, with billions manufactured by the 1970s. Radio became a ubiquitous "companion medium" which people could take with them anywhere they went.
Transistor radios were available in many sizes from console to table-top to matchbox. Transistors are still used in today's radios, though the integrated circuit containing a large number of transistors has surpassed the use of singly packed transistors for the majority of radio circuitry.
In the early 1950s, Ibuka traveled in Asia and heard about Bell Labs' invention of the transistor. He convinced Bell to license the transistor technology to his Japanese company. While most Japanese companies were researching the transistor for its military applications, Ibuka and Morita looked to apply it to communications. Although the American companies Regency Electronics and Texas Instruments built the first transistor radio as joint venture, it was Ibuka's company that made them commercially successful for the first time.
With the introduction of transistors, the earlier ones suitable for audio frequencies only, car radios were valve sets with a transistor output stage; makers promoted them as transistor sets. Some historic car radios badged as transistorised are in reality of this type. All-transistor sets eventually replaced sets with vacuum tube after transistor technology improved and prices fell significantly.
Chrysler and Philco announced an all-transistor car radio in the April 28, 1955 edition of the Wall Street Journal. This Philco car radio model was the first tubeless auto set in history to be developed and produced. It was a $150 option for 1956 Chrysler and Imperial cars and hit the showroom floor on October 21, 1955.
In February 1955 the second transistor radio, the 8-TP-1, was introduced by Raytheon. It was a larger portable transistor radio, including an expansive four-inch speaker and four additional transistors (the TR-1 used only four). As a result, the sound quality was much better than the TR-1. An additional benefit of the 8-TP-1 was its efficient battery consumption. In July 1955, the first positive review of a transistor radio appeared in the Consumer Reports that said, "The transistors in this set have not been used in an effort to build the smallest radio on the market, and good performance has not been sacrificed." Following the success of the 8-TP-1, Zenith, RCA, DeWald, and Crosley began flooding the market with additional transistor radio models.[12]
There are many claimants to the title of the first company to produce practical transistor radios, often incorrectly attributed to Sony (originally Tokyo Telecommunications Engineering Corporation). Texas Instruments had demonstrated all-transistor AM (amplitude modulation) radios as early as May 25, 1954,[7][8] 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.[9] 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.[10]
Before the transistor was invented, radios used vacuum tubes. Although portable vacuum tube radios were produced, they were typically bulky and heavy. The need for a low voltage high current source to power the filaments of the tubes and high voltage for the anode potential typically required two batteries. Vacuum tubes were also inefficient and fragile compared to transistors, and had a limited lifetime.
Colby's first invention was the Colby TR-2 transistor radio, which he designed at the precocious age of 12 and sold to family, friends and customers on his paper-route, and is possibly the first pocket transistor radio. At 15, he built for his high school science project the world's first home earth satellite station capable of receiving signals from the Russian satellite Sputnik. As a college student, his passion for radio and inventing brought him attention in the LA Times when he and a friend built their own TV stations to broadcast video to each other over the airwaves. Shortly afterwards, he built a video security system for use by NASA.
In electronics, a transistor is a semiconductor device commonly used to amplify or switch electronic signals. Because the controlled output power can be much larger than the controlling input power, the transistor provides amplification of a signal. The transistor is the fundamental building block of all modern electronic devices, and is used in radio, telephone, computer, and other electronic systems. From November 17, 1947 to December 23, 1947, John Bardeen and Walter Brattain at AT&T Bell Labs, underwent experimentations and finally observed that when two gold point contacts were applied to a crystal of germanium, a signal was produced whereby the output power was larger than the input. The manager of the Bell Labs semiconductor research group, William Shockley, saw the potential in this and worked over the next few months greatly expanding the knowledge of semiconductors in order to construct the first point-contact transistor. Shockley is considered by many to be the "father" of the transistor. Hence, in recognition of his work, the transistor is widely, yet not universally acknowledged as the most important invention of the entire 20th century since it forms today's building blocks of processors found and used in almost every modern computing and electronics device. In recognition of their invention of the transistor, Shockley, Bardeen and Brattain were jointly awarded the 1956 Nobel Prize in Physics.
The transistor is the fundamental building block of modern electronic devices, and is ubiquitous in modern electronic systems. Julius Edgar Lilienfeld patented a field-effect transistor in 1926[1] but it was not possible to actually construct a working device at that time. The first practically implemented device was a point-contact transistor invented in 1947 by American physicists John Bardeen, Walter Brattain, and William Shockley. The transistor revolutionized the field of electronics, and paved the way for smaller and cheaper radios, calculators, and computers, among other things. The transistor is on the list of IEEE milestones in electronics,[2] and Bardeen, Brattain, and Shockley shared the 1956 Nobel Prize in Physics for their achievement.[3]
Guarin convinced the government to give every peasant the - at that time - newly invented transistor radio, which enabled the education of over four million peasants.
Media related to Transistor radios at Wikimedia Commons Focusing on the history and design elements of early pocket transistor radios. by Dr. Steven Reyer, a Professor in the Electrical Engineering and Computer Science Department at the Milwaukee School of Engineering.Category:Transistor —hundreds of photos and detailed information on early transistor radios from the U.S., Japan, Western Europe, the former East Bloc and USSR. Historical data accompanied by hundreds of images covering early transistor radios. Web site with many historical references on the web and in published literature . In depth coverage of the Regency radio. . ". .
The invention of the transistor in 1947 revolutionized radio technology, making truly portable receivers possible, beginning with transistor radios in the late 1950s. Although portable vacuum tube radios were made, tubes were bulky and inefficient, consuming large amounts of power and requiring several large batteries to produce the filament and plate voltage. Transistors did not require a heated filament, reducing power consumption, and were smaller and much less fragile than vacuum tubes.
The reflex receiver, invented in 1914 by Wilhelm Schloemilch and Otto von Bronk, and rediscovered and extended to multiple tubes in 1917 by Marius Latour and William H. Priess, was a design used in some inexpensive radios of the 1920s which enjoyed a resurgence in small portable tube radios of the 1930s and again in a few of the first transistor radios in the 1950s. It is another example of an ingenious circuit invented to get the most out of a limited number of active devices. In the reflex receiver the RF signal from the tuned circuit is passed through one or more amplifying tubes or transistors, demodulated in a detector, then the resulting audio signal is passed "again" though the same amplifier stages for audio amplification. The separate radio and audio signals present simultaneously in the amplifier do not interfere with each other since they are at different frequencies, allowing the amplifying tubes to do "double duty". In addition to single tube reflex receivers, some TRF and superheterodyne receivers had several stages "reflexed". Reflex radios were prone to a defect called "play-through" which meant that the volume of audio did not go to zero when the volume control was turned down.