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Historical
Background
Although best known for
introducing the first commercial silicon transistors (in 1954) and the
first commercial integrated circuits (in 1959), Texas Instruments initially
entered the semiconductor market with germanium transistors, especially
those designed for use in commercial AM radios. Throughout the 1950s, TI
was a major supplier of these devices to many of the transistor radio
manufacturers, such as Admiral, Bulova, Emerson, Heathkit, Magnavox, Motorola,
Regency, Westinghouse, and Zenith. TI initially entered this market in
1954, when the first all transistor radio, the Regency TR1, was jointly
developed by TI and introduced in Dec 1954.
TI supplied a complete range of these transistors, suitable for all
elements of radio circuitry. For example, the 2N172 was intended for use
in the converter circuitry of AM radios. By the early 1960s, the type
2N172 was discontinued and replaced by the type 2N252; a 1961 TI price list
shows the 2N252 available from distributors at $2.45 each. Other TI germanium
radio transistors included the 2N145, 2N146, 2N147, 2N148, 2N149, 2N150, 2N185,
2N238, 2N252, 2N253, 2N254, 2N291, 2N308, 2N309 and 2N310. TI
manufactured germanium transistors well into the 1960s.
You can use these classic
germanium devices to repair your favorite old-time transistor radio, or to
build a circuit from that timeframe with a truly historic transistor. See
the chart at right to determine the type of transistor best suited for your
application.
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