Dr. John Saby

Oral History – John Saby

What unique problems were addressed with the early production units and what types of applications were developed?  

The major practical problem was the degradation of the junctions, due to atmospheric moisture.  This was solved by a distinctive hermetic case design developed by Conrad Zierdt, an engineer in the product department.   This “tophat” design was widely made and used by GE.  Using transistors made by my group, there were demonstration devices made in the E-Labs Transistor Circuits Section under R.F. Shea.  There was a “loudhailer” megaphone and a “personal hearing aid” for Shea – these devices used the early transistors potted in epoxy.  There was also an audio amplifier, which used “liquid-vapor” cooled power transistors, mounted in existing steel vacuum tube shells.  This was demonstrated at the IRE national Convention in 1953/54.



This is an example of an early “tophat” style germanium alloy transistor. This case style, developed by GE engineer Conrad Zierdt, provided a very effective (evacuated) hermetic seal and was widely used by GE over the 1950s and 1960s for the manufacture of millions of transistors. The research work done by John Saby at the GE E-Labs in 1951 and 1952 on the first alloy-diffusion junction transistors led directly to the successful commercialization of junction transistors by GE in 1953, with the “tophat” style 2N43/44/45 announced in November of that year.

Early Transistor Publications and Patents by Dr. John Saby


Recent Developments in Transistors and Related Devices, Reprinted from Tele-Tech, December 1951, by Dr. John S. Saby, Electronics Laboratory, General Electric Co, Syracuse, NY.


U.S. Patent #2,999,195, Original filed June 14, 1952. “BROAD AREA TRANSISTORS”, granted Sept 5, 1961.


Germanium Transistors, by Dr. John S. Saby, General Electric Review, September 1952.


Impurity Diffusion and Space Charge Layers in “Fused-Impurity” p-n Junctions, by John S. Saby and W. C. Dulap Jr, The Phsical Review, Vol 90, No. 4, 630-632, May 15, 1953.




Here is a photo of Dr. Saby, shown in the September 1952 General Electric Review, holding a small experimental radio transmitter that was built to demonstrate the possibilities of his “alloy-diffusion” transistors.


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