Bernard N. Slade

Oral History – Bob Slade


Oral History – Bob Slade



The first transistors were point contact devices.  Please provide some details about how you established the processes for building the early RCA developmental point contact transistors.


I had absolutely no work experience. I also  shared with most people in the electronics industry, except for Bell Telephone Lab., virtually total ignorance of what the transistor was, how it worked, and how to make one. The disadvantage of this situation was that I had no idea of where to begin. The advantage was that it created an enormous opportunity. The first task was to read every bit of published information on the subject. This didn’t take very long because at that time there was very little available. However, Bell generously shared much of what it had learned, and this information was very valuable. I formed a small laboratory with one technician and fairly rudimentary equipment for assembling and measuring the devices I planned to fabricate. The equipment consisted of tweezers, a welder to attach the tiny wires, a hot plate and soldering iron,  a microscope, and some pots and pans for etching and washing the germanium crystals.


The  laboratory was located in an late 19th century building without air conditioning, in the heart of a dirty industrial area, in the summer very hot and humid, the worst possible environment for a semiconductor laboratory. Yet despite these handicaps, we were able to learn a great deal about the technology and its behavior under different conditions.



Go To Slade Oral History, Page 4




This is a photo of one of the point contact transistors designed by Bob and built by the RCA Semiconductor Advanced Development group.  These early units, beginning around 1950, were hand-built and adjusted, tested, serialized, and labeled.  The TA165 was the most common type (likely a few thousand were built). As shown above, red ink was used to identify the type (TA165) and the serial number (29).  No date codes were used. The case was constructed using a plastic epoxy resin, known as Araldite.  The oval shape of the case was the result of using medicine capsules as the case mold.  Other models of this style of point contact transistor were developed, using differing physical parameters such as spacing of the points and doping of the germanium die (N or P type).  [5]  These devices were categorized within RCA as “developmental”, meaning that they were intended to be used by circuit engineers to develop potential applications for this new technology (radios, televisions, amplifiers, etc).  The “TA” was the internal RCA designation, meaning Transistor Amplifier, which indicated developmental status.  Bob’s team developed a small number of different TAXXX point contact transistor types. 



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