TRANSISTOR MUSEUM™

Historic Transistor Photo Gallery   

 

 

Transistor Size (5/16”L X 3/16”W X 5/16”H) 

Example of Date Code 8-54 (1954 Week 8)

 

Text on Cardboard Package

Overall Cardboard Package Size

Approx (2 1/2” by 3 1/2“)

 

WESTERN ELECTRIC

2N27

 

TYPE

Germanium NPN Grown Junction

Transistor

 

USAGE

Small Signal Transmission

Audio Amplifier

 

DATE INTRODUCED

Mid 1950s

 

CASE STYLES

Metal Hermetically Sealed

 

AVAILABILITY

Rare (Limited Production)

HISTORIC NOTES

The 2N27 is an interesting device from the first days of transistor manufacturing at Western Electric.  Developed in the mid 1950s, the 2N27 illustrates the early efforts to develop a metal case which was capable of protecting the internal transistor junction from temperature and humidity.  As can be seen in the photo shown above, the cases were crudely constructed, with what appears to be hand-soldered areas at the case bottom.  The leads of the 2N27 are embedded in a glass header, which undoubtedly contributes to the hermetic seal of the device.  Also of interest is the method used to identify the transistor model – some of the early units were marked with color-coded paint dots to indicate model 2N27.  The standard electronic color code uses “Red” for “2” and Violet” for “7”.  The 2N27 saw very limited use in phone equipment and was likely out of production by the late 1950s.  An additional important historical fact relating to the 2N27 is that this was the first “2N” type assigned to a junction transistor.  The earlier “2N” numbers, 2N21 through 2N26, were all associated with point contact transistor types.

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