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1996 - 2016
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RF Cafe began life in 1996 as "RF Tools" in an AOL screen name web space totaling 2 MB. Its primary purpose was to provide me with ready access to commonly needed formulas and reference material while performing my work as an RF system and circuit design engineer. The Internet was still largely an unknown entity at the time and not much was available in the form of WYSIWYG ...
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June 1958 Radio-Electronics[Table of Contents]
These articles are scanned and OCRed from old editions of the Radio & Television News magazine. Here is a list of the Radio-Electronics articles I have already posted. All copyrights are hereby acknowledged.
Just before Christmas in 1947, Bell Labs' John Bardeen, Walter Brattain, and William Shockley announced their invention of the first semiconductor device capable of producing positive signal amplification. They dubbed it the 'transistor' because it was a transconductance amplifier. In very short order, the laboratory experiment consisting of a metallic point contact (a piece of gold foil) interfaced with a slab of purified and doped germanium became commercially available at a price that easily competed with a vacuum tube amplifier when the cost of the socket and high voltage biasing transformers were factored in. Transistors would not be able to entirely replace tubes for many decades, especially for high power and high frequency applications, but as you can see today, the only vacuum tube the average person will find anywhere is in an old computer or TV CRT display or in an antique radio set sitting on someone's shelf.
Schematic of first transistor
1948-Early "point contact" transistor (left).
In 1948, Bell Telephone Laboratories announced the invention of the transistor. In 1958, the transistor provided the radio voice for the first United States satellite.
To advance the transistor to its high level of usefulness, Bell Labs had solved problems which, in themselves, approached the invention of the transistor itself in scientific achievement.
First, there had to be germanium of flawless structure and unprecedented purity. This was obtained by growing large single crystals - and creating the "zone refining" technique to purify them to one harmful part in ten billion.
'The "junction" transistor, another radical advance, spurred transistor use. Easier to design, lower in noise, higher in gain and efficiency, it became the heart of the new electronics.
An ingenious technique for diffusing a microscopically thin layer on semiconductors was created. The resulting "diffused base" transistor, a versatile broadband amplifier, made possible the wide use of transistorized circuits in telephony, FM, TV, computers and missiles.
In telephony the transistor began its career in the Direct Distance Dialing system which sends called telephone numbers from one exchange to another.
For Bell System communications, the transistor has made possible advances which would have been impossible or impractical a brief decade ago.
1958-Satellite transistor, incorporating 10 years
of Bell Labs research and development.
WORLD CENTER OF COMMUNICATIONS RESEARCH AND DEVELOPMENT
Posted June 7, 2014