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;

Doping;

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:

 

 

Prototype

G Series

RMA

Amplifier/oscillator

SX-4A

G11

2N30

Switching

Z2

G11A

2N31

Date

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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