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What Is a Transistor Radio?

Rebecca Mecomber
Rebecca Mecomber

The transistor radio is a compact, portable radio that uses a transistor radio receiver to receive and amplify radio sound waves. The development of the transistor radio in the late 1940s and 1950s revolutionized radio electronics. Previously, all types of radios consisted of fragile glass vacuum tubes housed in large, heavy and cumbersome cases. This radio consists of a small, solid state semiconductor chip that receives and amplifies sound waves from radio stations and other broadcasting devices. The small size of the transistor radio coupled with its durability and long battery life made the device the first portable radio that influenced modern culture and the development of smaller, faster electronic devices.

After World War II, scientists and electronic developers sought ways to improve radio and radar communications for the United States military. Scientists at Bell Labs developed a unique build of semiconductors consisting of a sandwich of germanium crystals and metal diodes. These linked semiconductors, called a transistor, received and transmitted radio waves in greater capacity and with greater clarity than the vacuum tube devices. This new technology spawned the development of modern telephony and computers but was not yet marketable to consumers on a grand scale for several more years.

The 2n2222a transistor is a commonly used in devices such as radios.
The 2n2222a transistor is a commonly used in devices such as radios.

In 1954, Regency Electronics and Texas Instruments incorporated the transistor into the first portable transistor radio. The Regency TR-1 radio was a slim, five-inch high, plastic box with a large round radio dial and a smaller volume dial. Regency sold the transistor radios in a variety of colors, and consumers snapped up the radios within a few months. American radio companies were slow to adopt these radios into mass production, however. A Japanese company by the name of Tokyo Tsushin Kogyo filled the transistor radio production vacuum. Changing their name to the more pronounceable Sony, the company dedicated its entire production to creating transistor radios for the American consumer.

The transistor radio made news, information and music instantly mobile. The tiny radio fit perfectly into the pocket and the 22.5 volt (22.5 watt/ampere) battery extended for nearly 24 hours. American society was primed for the transistor radio: prosperity and disposable income grew to exponentially high levels after World War II, and the population explosion and interest in faster and more efficient appliances and devices grew with it. Most importantly, young Americans with greater consumer clout discovered that this radio gave them more liberal music choices separate from the traditional family vacuum tube radio, forging the era of modern rock music.

While transistor radios have phased out due to later developments such as the boom boxes of the 1980s, the compact disk players of the 1990s, and the mp3 players of the 2000s, scientists and electronic developers point to the transistor radio as a spearhead of the modern electronic age. Microsoft founder Bill Gates pointed to the transistor as the precursor of the personal computer. Fortune magazine argued that the transistor was "the most important invention of the 20th century." This radio, as tiny as it was, also epitomized the massive post-war power of the American consumer.

Discussion Comments


Gates was right. Computers used to use vacuum tubes, too, and were huge and somewhat unreliable in those days. Transistors replaced valves, paving the way for smaller, more reliable computers. Computers were much more affordable, too, thanks to transistors and that low cost made it possible for consumers to afford the things after home computers hit the market.


Let's not forget that one of the reasons the transistor radio replaced ones powered by tubes was sheer convenience. Transistor radios could be portable, you didn't have expensive tubes to replace and the things didn't have to "warm up" to be useful.

That last point is a very important one. I had a 1955 Chevrolet Bel-Air in high school and the thing had it's original, tube radio. It worked but was mostly for show because it took a bit for the tubes to warm up before you could listen to anything. We installed a transistor radio so we could turn it on and just have it work.

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    • The 2n2222a transistor is a commonly used in devices such as radios.
      By: yurazaga
      The 2n2222a transistor is a commonly used in devices such as radios.