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TRANSISTOR
MUSEUM™ Historic Transistor Photo
Gallery Photo Essay – Bell Labs
Bead Type Point Contact |
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Assembly View of Cartridge and Bead Type Transistors |
Unique Hybrid Sample Point Contact Transistor |
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Photo
Essay Commentary The
two transistor types illustrated in the drawing above (left) represent the
mature versions of the cartridge type and the bead type point contact
transistors at Bell Labs/Western Electric through the mid 1950s [4]. The cartridge type had evolved from the
earlier Type A transistor [1]
and the bead type had evolved from the small circular plastic bead
experimental type shown earlier in this photo essay. The photo (above right) represents an
experimental, hybrid case point contact transistor – it is likely that this approach
was used to take advantage of the socket mount capabilities of the cartridge
type. The
model numbers used to identify developmental and the corresponding RTMA/Jetec
numbers for all documented bead type BTL/Western Electric point contact
transistors are shown in the table below [5].
Go
To PhotoGallery Bead Type Pct Page 5 |
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Copyright © 2004 by Jack Ward. All Rights Reserved. http://www.transistormuseum.com/ PAGE 4 |
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