An Interview with Carl David Todd

 Recollections from the First Days of Transistor Technology


Oral History – Carl David Todd (Continued)


I can imagine you had quite a few   interesting experiences involving early transistor technology during your years at GE.   Would you please recount some highlights?


Point Contact Transistors:

First of all, the point contact transistor was an absolute beast to apply and unstable as all heck.  Second of all, the yield was absolutely terrible and automation was much more difficult to imagine for the G11 series.  It was also difficult to get them to the customer in working order (remember my comments about the three dead point contact transistors I bought from Western Electric).  Imagine the customer who tried to use a mechanically unstable device like the point contact transistor in an application where there was to be normal shocks and vibration.  I laughed my head off when I was nosing around at SKEL labs at Fort Monmouth.  There was one proposed design using a point contact transistor in an RF telemetry system in a mortar shell!   


What tickled me was that when I went for my Professional Engineer exam in 1964, you are allowed to pick certain questions that are a part of your expertise.  The only question that had anything to do with semiconductors was “Design an oscillator using a point contact transistor, and show exact waveforms at all points”.    That was funny!  Whoever wrote this thing never did design with a point contact transistor – you don’t design with paper, you do a lot of trial and error.




Oral History – Carl David Todd (Continued)




These are point contact transistors from the early 1950s, which Carl worked with at Auburn and GE.  The top unit is a classic cartridge type, developed initially at Bell Labs and Western Electric.  The unit in the center is a GE G11/G11A, and the lower unit is a prototype of the G11, developed when GE was experimenting with different point contact packaging styles.  According to Carl, “The G11/11A point contacts were made in Syracuse.  When I got to GE, I tried to use these, but then told marketing that they just would not fly!  They were losing money on every one of them”.



Go To Todd Oral History, Page 6


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