H. C. Lin

Oral History – H. C. Lin


Oral History – H. C. Lin



Do you remember the ISL Symposium held at the RCA Labs in Princeton NJ, starting on Nov 18, 1952?

Yes, and by then I had left the RCA patent group and was working in the ISL group.  We had been told to develop applications for the new transistor. “Let’s try to see what you can use transistors for”.  Most of this group worked on transistor radios, but I was working on something else, an audio amplifier and a roving microphone.  I also developed a wireless, musical keyboard.  There were reporters at the Symposium, and they seemed to be impressed with these gadgets, which were unusual, and not so much with the radios. I did file a patent on the tone modulated oscillator for the Roving Microphone.


What transistors did you use in these devices?

I remember the TA153; these were built by Charlie Mueller and Jack Pankove.  Another name associated with early RCA transistors was Herb Kroemer (recent Nobel winner) for the drift transistor.  Now, every transistor is a drift transistor, but he was the first to use it.  He built drift transistors using two different concentrations (graded) in the base.  But, actually, you can never have an abrupt change, but are always graded.  So, today’s double-diffused transistor is the same as a drift transistor.  All these early transistors were quite different in performance (beta) and one of our jobs was to develop stabilized circuits that would work even with these variations.  Even today, there is a wide variation in beta for transistors, and you have to use them in such a way as to accommodate this. 






As Dr. Lin details in the Oral History, while working at the RCA ISL labs in the early 1950s, he was assigned the task of developing new and interesting applications for the just-emerging  transistor technology.  Above is a photo from a 1953 RCA publication entitled “Transistors - today and tomorrow” which shows Dr. Lin with one of his early transistor applications.  This device, a two transistor Roving Microphone, was the basis for a patent and was also used successfully at a 1952 RCA Transistor Symposium to demonstrate the great potential for this new technology.  In the photo, the Roving Microphone is the long, thin hand-held device in Dr. Lin’s left hand.  More information regarding the Roving Microphone is provided on later pages of this Oral History.






Go To Lin Oral History, Page 3



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