TRANSISTOR MUSEUM Historic Transistor Photo Gallery
Transistor Size (5/16”L X 3/16”W X 5/16”H) Date Code 3-57 (Month 3, 1957) Packaging - None	WESTERN ELECTRIC TYPES 4B and 4C TYPE Germanium NPN Grown Junction USAGE Voice and Carrier Frequency Telephone Equipment DATE INTRODUCED 1957 CASE STYLES Grey Painted Metal AVAILABILITY Rare (Limited Production)
HISTORIC NOTES Because transistors offered potential advantages over vacuum tubes in higher reliability, lower power requirements and smaller size, Western Electric was eager to utilize this new technology in the 1950s. An obvious choice was in the voice and carrier telephone systems manufactured and employed in large quantities by Western Electric to accommodate the rapidly growing number of phone calls in the U.S. The types 4B and 4C devices were production quality transistors developed and manufactured by Western Electric in Allentown, Pa. in the mid 1950s. These transistors had been developed from earlier prototypes, including type 1858 developmental transistor. By 1957, the types 4B (for voice systems) and 4C (for carrier systems) performed well enough to be used in production for the telephone systems equipment. These transistors were of the grown junction type, which was the first junction transistor technology, developed at Bell Labs in the early 1950s. Grown junction technology was largely obsolete by the early 1960s.
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