Transistor Museum Lecture Hall

“The Early History of Transistors in Germany”

Rudi Herzog (Continued)

1957

In January VALVO has the first real RF transistor OC44 for application in RF mixers. TELEFUNKEN has similar type OC613.

Now the transistor-line for production of an industrial transistor radio was complete. It was again at the Industrial Fair in April when the first two transistor pocket-sized radios appeared:

TELEFUNKEN showed the “Partner“, a 5-transistor-set.

Only 3 weeks earlier AKKORD came with its ”Peggie“, a 5-transistor-set as well.

VALVO produces sub-min transistors OC65, OC66 for hearing aid applications.

TELEFUNKEN has the power-transistor OD605 ( 15 watts ).

By the end of 1957 the following German transistor companies were involved in manufacturing:

TELEFUNKEN

VALVO

SIEMENS & HALSKE

TEKADE

INTERMETALL

.... and of lesser importance, as these two companies gave up on transistor manufacturing very soon in the late 1950‘s :

DR. ROST

S.A.F.

HOWALDTSWERKE

Rudi Herzog (Continued)

Something about the German classification of transistors

German Transistors had two letters and two or three numbers for type identification.

The first letter was the “O“ , showing that this device needed no heating compared to electronic tubes.

The second letter was the letter “C“ , showing this was a triode . This C was used for tubes as well ,

i.e. EC92 , which was triode .

If the second letter was a “D“, this transistor was a “power“-type , which at that time could be some hundred milliwatts or even some watts.

VALVO used two-digit numbers for classification, as well as TEKADE and SIEMENS & HALSKE.

TEKADE hadt a classification of its own. Their transistors started with GFT (for germanium junction transistor ), whereas TELEFUNKEN used three-digit numbers, as did INTERMETALL.

2001

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