File:Bell telephone magazine (1922) (14756190305).jpg

Identifier: belltelephonevol3132mag00amerrich (find matches)
Title: Bell telephone magazine
Year: 1922 (1920s)
Authors: American Telephone and Telegraph Company American Telephone and Telegraph Company. Information Dept
Subjects: Telephone
Publisher: (New York, American Telephone and Telegraph Co., etc.)
Contributing Library: Prelinger Library
Digitizing Sponsor: Internet Archive

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at we must purify the ger-manium to an even higher degreeof purity—then introduce the knownand carefully controlled impuritywhere we want it. The germaniumso prepared may very well be thepurest material in existence. Sof?ie Telephone Uses In the Laboratories many possibil-ities are now being explored. Will next. The problem was to get thegermanium into one big perfect crys-tal. Our chemists and metallurgistsdid this. In fact, theyhave found several waysto make single crys-tals. This source ofdifficulty is now wellpast—all transistors arenow made of singlecrystal germanium inwhich the successive lay-ers of atoms are care-fully ordered, one uponthe other. The question of pur-ity has also been vital.Transistor action de-pends on the presencein the germanium crys-tal of a very few for-eign atoms—perhapsone foreign atom foreach 100,000,000 ger-manium atoms—andtheir arrangement in likely, and very promising. Promis-ing in terms of what can be done,speed of operation, power and space
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The ease with which electrons move in a semiconductorcrystal is an impor-tant fundamental measurement herebeing performed by Gerald L. Pearson (standing) and J. R. Havnes 78 Bell Telephone Magazine SUMMER needed, as well as probable cost andreliability in service. In our auto-matic telephone exchanges today thereare substantially no operators. Buteven with mechanization, electronicshas had only a small part to play inthe evolution of complex switchingsystems such as No. 4 and No. 5 cross- in communities or improving long dis-tance communication? It will have arole to play in both. It may well bethat broadband circuits for long dis-tance uses will take new form throughlower circuit mile costs that the tran-sistor will make possible. New oppor-tunities for extensive distribution of bar. Transistors, as well as other television in urban areas are possible, solid-state devices, with their capabil- The transistor may allow the use of ity of high speed operation, their our carrier methods o

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