Sony Tr-55
The Sony TR-55 was the first Japanese transistor radio, a small five-transistor receiver released in 1955 by Tokyo Tsushin Kogyo, the company that would be renamed Sony in 1958. It was an early product of the firm that built its identity on miniaturised consumer electronics, and it is the beginning of the story in which Japanese manufacturers turned an American invention into a worldwide consumer category, following the Regency TR-1 of 1954 in time but taking a different path in the market.
The TR-55 followed from a licensing decision and years of hard component engineering. Masaru Ibuka, the company's engineering-minded co-founder, learned of the transistor on a visit to the United States in the early 1950s, and the company acquired a license from Western Electric around 1953 to 1954 at the price set for the industry, 25,000 dollars. The harder task was making transistors that could amplify at the radio frequencies a receiver needs, since many early devices were suited only to audio, and Tokyo Tsushin Kogyo's engineers worked at improving yields and frequency response themselves rather than buying components. The TR-55 carried the company's own transistors, and the work on materials and devices from this period gave the firm the technical depth that later products depended on.
The TR-55 and its successors were sold under a brand built for a world market. The Sony name was coined in the mid-1950s, derived from the Latin sonus (sound) and the word sonny, and it began appearing on products between 1955 and 1958, before the company formally took the name in January 1958. Akio Morita, the co-founder who handled sales and marketing, pressed for a short brand name that could be read and pronounced anywhere, and pursued export markets, notably the United States, at a time when "made in Japan" suggested cheap goods. The first TR-55 was sold mostly at home in limited numbers, but its direction was clear: small, cleanly designed receivers aimed at buyers abroad.
The TR-63 of 1957 is the model that made the pocket radio a mass export product. A smaller, six-transistor set designed to fit in a pocket, it went on sale in Japan and was exported, and it became the symbol of the compact transistor radio abroad. By the end of the 1950s, Japanese makers including Sony, along with others, were exporting transistor radios in volume, undercutting American prices, and the segment became one of Japan's early successful electronics exports. This is the reason the TR-55 and TR-63 are paired in histories: the first marks the technical beginning at home, and the second the product that carried the category outward.
The connection to Leo Esaki shows that the company was doing basic semiconductor research, not just assembling radios. Esaki, a Japanese physicist then working at Tokyo Tsushin Kogyo, observed the negative-resistance tunnelling effect in heavily doped germanium junctions in 1957, leading to the tunnel diode, and he later shared the 1973 Nobel Prize in Physics for the work. The finding came from the effort to understand and improve the junction devices the company needed for its radios, and it is a good example of how production problems can feed back into science. Tunnel diodes were used in fast switching and microwave circuits for a time but were largely displaced by other devices.
A common misconception is that the TR-55 was Sony's first product, or that it was the first Japanese radio using a transistor in any form. The company had earlier products such as tape recorders and had experimented with transistor circuits before; the TR-55 was simply the first complete commercial transistor radio from Japan. Another confusion is the branding: the earliest sets carried the company's older name, and the Sony brand grew on products over the next few years. The modern relevance is the business pattern, in which a firm licenses a foreign technology, improves its manufacturing, and sells a smaller, more convenient version to the world.
Read Sony TR-55 as the first step of a Japanese company from licensee to global brand: a five-transistor radio of 1955 whose real legacy was the engineering base, the export strategy and, soon after, the research culture that produced the TR-63 and Esaki's tunnel diode.