TRANSISTOR MUSEUM Historic Transistor Photo Gallery
Transistor Size (5/16”L X 1/8”W X 5/16”H) Date Code 533 (1955, Week 33) Packaging-None Outline of Texas Stamped on Back of Case	TEXAS INSTRUMENTS 900 – 905 SERIES TYPE Silicon NPN Grown Junction Low Frequency Amplifier USAGE Military DATE INTRODUCED 1954 CASE STYLES Silver Metal AVAILABILITY Rare (Limited Production)
HISTORIC NOTES Texas Instruments was the first company to offer silicon transistors commercially, announcing the 900 – 905 series of grown junction units in mid-year 1954. This was several years before other companies were able to produce commercial silicon units, and this early introduction allowed Texas Instruments to gain a large share of the highly profitable military transistor market – silicon units performed reliably at much higher temperatures than germanium units and were in great demand by the US military. The earliest TI silicon units (as shown in the photo above) are easily identified by the stamped id number (905, for example) on a crude unpainted metal case. All TI units of this type (early and late) had a stamped outline of the state of Texas on the back of the case. The first units sold for over $100 each and the cost remained high for many years. As late as 1965, the Allied Electronics catalogue listed the TI 2N117 type for $8.15, when most comparable germanium units were available in the $1.00 range. The 2N117 was one of the “follow on” commercial types based on the original 900 series.
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