Wednesday, April 25, 2007

The Transistor Radio (part 2)

The transistor radio was the first hand-held audio device. As a concept, it preceeds the walkman, the discman and the I-pod. Before the transistor radio music was stationary. Radios were furniture and often marketed and sold as such. The transistor radio could go anywhere, and they did. It sees strange to see them reduced to a kitchy almost ironic promotional tchotchke. I still want one though.

Prior to the transistor, Vacuum tubes were the only way to amplify signals or function as switching devices. The problem with tubes is that they were expensive, energy inefficient, hot, and burned out. In the 1940’s Bell Labs set a a team of scientists to work to replace the vacuum tube. They worked out of an office in Murray Hill, NJ.

By 1947 they had it. Their original patent name for the transistor was: “Semiconductor amplifier; Three-electrode circuit element utilizing semiconductive materials.” But they decided that transistor was more catchy.

The scientists that were responsible for the 1947 invention of the transistor were: John Bardeen, Walter Brattain, and William Shockley. Bardeen, with a Ph.D. in mathematics and physics from Princeton University, was a specialist in the electron conducting properties of semiconductors. Brattain, Ph.D., was an expert in the nature of the atomic structure of solids at their surface level and solid-state physics. Shockley, Ph.D., was the director of transistor research for Bell Labs. As a group they invented the point-junction transistor.
Shockley thought his name should be on the patent. The Bell Labs attorneys didn't agree. But they were notorious assholes. They refused to put his name on the patent -at all! Shockley gave them the finger and decided to take the rest of his ideas elsewhere. So while his old co-workers were improving on the point-junction transistor he was in the garage playing mad scientist.
In early 1948, Shockley was alone on New years eve in a Chicago Hotel room. History does not say if he was invited to the party in the hotel lobby, but it's clear that his idea of fun was writing 30 pages of notes on this idea he had. He'd read about Bardeen and Brattain's semiconductor ideas. His idea was to pile three layers of semiconductors together, thinking it may work like a vacuum tube-with the middle layer turning current on and off.
The physics behind this transistor was different from the one developed with Bardeen. This one had current flowing directly through the semiconductors, not along the surface. He wasn't even sure if it was possible. But it was a new idea. And it was one that nobody else could lay legal claim to. This puppy was going to have his name on thepatent. So he tested it before he discussed it with anyone. His co-workers Joseph Becker and John Shivewere pretty impressed, but also peeved to have been left out of the loop. More here.
Interesting side note, Bardeen was the first person to win two Nobel prizes in the same field. He shared the physics prize for the first time in 1956 for the transistor. Then he won it again (shared again) in 1972 for the development of the BCS theory of superconductivity.

Within ten years, Motorola debuted a germanium transistor that widened the possibilities of what transistors could do. It was the world's first commercial high-power transistor. It was also Motorola's first mass-produced semiconductor. Things got cheaper, faster, smaller and easier. Ain't life grand.