Historic Transistor Photo Gallery

Photo Essay – Bell Labs M1752



M1752 Transistor Courtesy Terry Hosking



M1752 Transistor Courtesy Terry Hosking



Photo Essay Commentary

These close-up photos provide a detailed view of a very well preserved M1752.  The red paint on the side was used to identify collector electrode.  The case material is a black epoxy plastic.  This material does not provide adequate environmental protection and allows moisture to penetrate and destroy the transistor junctions.   According to Art Uhlir Jr,  the plastic epoxy was chosen initially with an idea to mass produce inexpensive transistors.  Due to the poor results, metal cases were used by most manufacturers until the 1960s, when manufacturing processes for transistors were greatly improved.               

Go To PhotoGallery M1752 Page3




Copyright © 2004 by Jack Ward. All Rights Reserved.