TRANSISTOR MUSEUM™  Historic Transistor Photo Gallery
Transistor Size (Approx .375 “ H) Date Codes 1950s – 1970s 1950s Western Electric 2N110 Packaging	WESTERN ELECTRIC 2N110 TYPE Germanium PNP Point Contact Transistor USAGE Military/Phone Company Switch Circuits (Severe Mechanical Environments)  DATE INTRODUCED Mid 1950s CASE STYLES Grey Metal (1950s) Black Metal (1960s) AVAILABILITY Rare (Limited Production)
HISTORIC NOTES The transistor was invented at Bell Labs in late 1947.  This first transistor technology was known as “point contact”, a term which referred to the construction process of two pointed wires or contacts that were physically pressed down onto a germanium block.   These first transistors were sensitive to any mechanical shock that caused internal movement.  (See Bead Type Point Contact Transistor). Point contact technology was quickly superceded by more stable and manufacturable transistor types, such as grown junction and alloy junction; however, Bell Labs/Western Electric continued limited work on the original point contact technology, and had developed a physically stable version of this device type by the mid 1950s.  The 2N110 point contact transistor is an example of this “ruggedized” point contact transistor.  As with all Western Electric transistors, the 2N110 was not sold commercially, but was used for phone company and military applications.  Western Electric continued to manufacture the 2N110 into the 1960s (long after the mid 1950s obsolescence of point contact transistors). This was most likely required by the military for replacement units.  At least one other company, Kierfott, manufactured the 2N110.  Shown above is a 1970, gold-plated Kierfott 2N110.
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