Have extra ge. G11a. First GE landmark transistor for counter and computer cicurits

ED SHARPE couryhouse at aol.com
Fri Feb 14 20:28:47 CST 2020

Ok offer me offlist for our extra transistor unused  in box sealed in original cellophan6...
Have extra ge. G11a. First GE landmark transistor for counter and computer cicurits

Germanium Whisker Transistors


Robert Hall returned to General Electric Research Laboratories Schenectady just as Bell announced its point-contact transistor.  Hall had just graduated PhD from Caltech and had previously worked at the laboratories on a range of projects including the Harper North Wartime radar diode project. Dr Albert Hull was Assistant Director of the Laboratory. He was known for his collegial management style with a relaxed approach to the research agenda of his staff members. Hall recalls that Hull came in with the reprint of the Physical Review letters that announced the transistor [Bardeen 1948] and said “Robert here’s an interesting development from Bell Laboratories. It looks like something pretty new and exciting. Would you like to look into it and see if there’s anything interesting there.” [Choi 2004]

General Electric had all the knowhow it needed to duplicate the Bell design quickly. North’s diode programme had diodes that could handle 100 volts back voltage which was state of the art at that time. (Purdue University produced the high back voltage germanium for the Bell point contact transistor.) North’s diode programme and related research ensured it had a manufacturing understanding of the key technologies:

High back voltage poly-crystalline germanium;


Point contact design;

Welding or forming; and

Assembly and encapsulation.

Its first designs were crude with two pins for the collector and emitter with the base connection through the case in the manner of the Bell Type A. No socket was available and users were recommended to use a 5 pin subminiature tube socket using positions 2 and 3 for the collector and emitter and to create a base connection by inserting phosphor-bronze strips in positions 1 and 4 and bending them so they contacted the transistor case.

The transistors were known as germanium triodes or germanium whisker transistors. Two types were produced evolving from prototype coding through the familiar “G” designation in use for its point-contact diodes and finally adopting RMA registration:




G Series











Up to 1951

1950 on

1952 on


The prototype numbers appear in early data sheets and in a General Electric price list dated June 1st 1951 in which the new SX-4A and Z2 transistors were priced at a massive $29 each.

The two transistors had the same mechanical and electrical characteristics but the switching transistor was tested for “trigger action” or negative resistance. [General Electric 1950 courtesy Jack Ward]

>From 1952 the transistors had 3 pins with the base connection being soldered to the outside of the transistor’s case.

See data sheet ECG-3B.

Early General Electric G11 and G11A point-contact transistors.[Courtesy Jack Ward]

Production General Electric G11 point-contact transistor [Courtesy Jan de Groot]

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