The Discovery of the Transistor

It began in 1939. Russell Ohl was studying crystals at Bell labs in the USA, and discovered the PN junction. Walter Brattain who was a research physicist at Bell labs, saw Ohl’s work and realised that it could lead to a solid state alternative to the thermionic valve. In December 1947 he produced the first working point contact transistor with John Bardeen. Early in 1948 William Shockley began work on a different concept which led to the development of the junction transistor. In July 1951 the world’s first junction transistor was announced in a press conference. In 1956 Walter Brattain, John Bardeen and William Shockley shared the Nobel prize for physics for their invention of the transistor.

How the Transistor Works

Transistor Radios

Transistors were first produced commercially by the American company Raytheon, in 1952. The first radio to be produced commercially was the Regency TR-1, which was also manufactured in America and went on sale in November 1954. It only used four Texas Instruments transistors, as transistors were then very expensive. It operated from a 22.5 volt battery and sold for $49.95. Sadly sales were none too good, mainly because of the high price. Within a very few years prices had fallen and transistor radios became very popular.

 

The Regency TR-1.

In the U.K. Mullard led the way, and by the mid 1950's was producing its highly successful 'OC' transistor range, including the OC44, OC45, OC71 and OC72. 

The first British transistor radio was manufactured by Pye in June 1956. It was the Pam model 710, that used 8 transistors made by Newmarket Transistors Ltd, which was a subsidiary of Pye. In the following January Pye launched a transistor radio under its own name. It was the Pye model 123 which was a vast improvement on the Pam model.  In August 1957 the Perdio PR1 appeared, but sadly it was notoriously unreliable, and in May 1958 the successful Super 7 was launched. Before the end of the decade most of the UK manufacturers were producing high quality transistorised receivers.


The Pam 710.
British manufacturers produced some of the highest quality transistor radios ever made, such as this Hacker Super Sovereign from 1975.
The super Sovereign control panel. Like the front panel it was an aluminium extrusion rather than the usual plastic.
A fine example of a locally made transistor radio is the Ever Ready Sky Master. It is a Medium and Long Wave Receiver with a rexine covered plywood case. It is quite sensitive and performs extremely well,

 


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