Point Contact Transistors


The first transistors developed by Bell Labs were Point Contact versions, created using an extension of diode manufacturing, which was a further refinement of diodes in 'cat's whisker' radios. 

This 2N110 is a Western Electric Point Contact transistor from the 1950s. Point Contact transistors were difficult to manufacture and were superseded by grown junction, then alloy junction versions.  Western Electric continued to manufacture them longer than any other company since they were designed into telephone Central Office systems on a large scale.

In the background is a page from Walter Brattain's logbook describing the first point contact transistor.

A little bit more information in this previous post : https://spingalhistory.blogspot.com/2017/02/bell-labs-point-contact-transistor.html

 

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