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CK722
The CK722 was the first low-cost junction transistor available to the general public. It was a PNP germanium small-signal unit. Developed by Norman Krim, it was introduced by Raytheon in early 1953 for $7.60 each; the price was reduced to $3.50 in late 1954 and to $0.99 in 1956. Norm Krim selected Radio Shack RadioShack, formerly RadioShack Corporation, is an American retailer founded in 1921. At its peak in 1999, RadioShack operated over 8,000 worldwide stores named RadioShack or Tandy Electronics in the United States, Mexico, United Kingdom, Austra ... to sell the CK721 and CK722 through their catalog. Krim had a long-standing personal and business relationship with Radio Shack. The CK722s were selected "fall out" from the Raytheon's premium-priced CK721 (which are fallouts from CK718 hearing-aid transistors). Raytheon actively encouraged hobbyists with design contests and advertisements. Raytheon sponsored a design contest for applications that used the CK722 transistor. Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CK722
The CK722 was the first low-cost junction transistor available to the general public. It was a PNP germanium small-signal unit. Developed by Norman Krim, it was introduced by Raytheon in early 1953 for $7.60 each; the price was reduced to $3.50 in late 1954 and to $0.99 in 1956. Norm Krim selected Radio Shack RadioShack, formerly RadioShack Corporation, is an American retailer founded in 1921. At its peak in 1999, RadioShack operated over 8,000 worldwide stores named RadioShack or Tandy Electronics in the United States, Mexico, United Kingdom, Austra ... to sell the CK721 and CK722 through their catalog. Krim had a long-standing personal and business relationship with Radio Shack. The CK722s were selected "fall out" from the Raytheon's premium-priced CK721 (which are fallouts from CK718 hearing-aid transistors). Raytheon actively encouraged hobbyists with design contests and advertisements. Raytheon sponsored a design contest for applications that used the CK722 transistor. Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Norman Krim
Norman B. Krim (1913–2011) was an American electronics engineer and engineering executive. His drive to create a transistor product for the electronics experimenter-hobbyist market contributed to paving the path for a generation of American electronics engineers and technicians during the Space Race between the United States and the Soviet Union. "The result was that a whole generation of aspiring engineers — kids, really, working in their garages and basements — got to make all kinds of electronic projects. A lot of them went on to become engineers." — Harry Goldstein, editor for IEEE ''Spectrum'' magazine. Early years Norm Krim was born June 3, 1913 Manhattan, New York, one of four children of parents Abraham and Ida Krim. He graduated from George Washington High School at age 16 then attended Massachusetts Institute of Technology (MIT) where he graduated 1934 in electrical engineering. He worked for most of his career for Raytheon, (over 75 years). He began as an e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
2N107
The 2N107 is an early germanium alloy junction PNP transistor developed by General Electric (GE) in 1955, to become GE's entry into the electronic hobbyist market successfully started with the CK722 transistor. Like the CK722, it enjoyed a long-standing popularity. General Electric decided to designate it with a JEDEC 2N- series identification. This is unusual for a hobby device. Soon after, other manufacturers got involved in the hobby business like Sylvania Electric Products, Sylvania, Tung-Sol and RCA. History A detailed story of the 2N107 conception can be heard with Jack Ward interviewing Carl Todd at the Semiconductor Museum website which much of this History section is based on. The 2N107 was conceived in 1955 by Carl David Todd, who had just joined GE as an engineer. Todd's interest in a hobby/experimental transistor probably originated when he participated in one of the CK722 transistor design contests, while he was an engineering student at Auburn University and fin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transistor
upright=1.4, gate (G), body (B), source (S) and drain (D) terminals. The gate is separated from the body by an insulating layer (pink). A transistor is a semiconductor device used to Electronic amplifier, amplify or electronic switch, switch electrical signals and electrical power, power. The transistor is one of the basic building blocks of modern electronics. It is composed of semiconductor material, usually with at least three terminals for connection to an electronic circuit. A voltage or current applied to one pair of the transistor's terminals controls the current through another pair of terminals. Because the controlled (output) power can be higher than the controlling (input) power, a transistor can amplify a signal. Some transistors are packaged individually, but many more are found embedded in integrated circuits. Austro-Hungarian physicist Julius Edgar Lilienfeld proposed the concept of a field-effect transistor in 1926, but it was not possible to actually cons ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Raytheon
Raytheon Technologies Corporation is an American multinational aerospace and defense conglomerate headquartered in Arlington, Virginia. It is one of the largest aerospace and defense manufacturers in the world by revenue and market capitalization. In addition, it is one of the largest providers of intelligence services. Raytheon Technologies manufactures aircraft engines, avionics, aerostructures, cybersecurity, guided missiles, air defense systems, satellites, and drones. The company is also a large military contractor, getting a significant portion of its revenue from the U.S. government. The company is the result of the merger of equals between the aerospace subsidiaries of United Technologies Corporation (UTC) and the Raytheon Company, which was completed on April 3, 2020. Before the merger, UTC spun off its non-aerospace subsidiaries Otis Elevator Company and Carrier Corporation. UTC is the nominal survivor of the merger but it changed its name to Raytheon Technologie ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alfred Powell Morgan
Alfred Powell 'Skipper' Morgan (1889–1972) was an electrical engineer, inventor of radio and mechanical devices, and author of technical and children's books from the U.S. state of New Jersey. Life and career Originally from Upper Montclair, New Jersey, Morgan attended the Massachusetts Institute of Technology and was a radio manufacturer for many years. He was a partner of Adams Morgan, an electronics company founded in around 1910 that distributed radio construction kits. Paul Forman Godley, developer of the Paragon Receivers, joined in 1915 as the third partner. The company employed 50-100 staff in 1922/23. Due to economic problems, production was halted at the end of 1927. Writing Morgan wrote many books on radio and electronics. He wrote a series of books on the subject for young people, including the Boys First, Second, Third & Fourth Book Of Radio And Electronics. Morgan had four sons, which is why his books were originally written for boys, but editions from the 19 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bipolar Junction Transistor
A bipolar junction transistor (BJT) is a type of transistor that uses both electrons and electron holes as charge carriers. In contrast, a unipolar transistor, such as a field-effect transistor, uses only one kind of charge carrier. A bipolar transistor allows a small current injected at one of its terminals to control a much larger current flowing between the terminals, making the device capable of amplification or switching. BJTs use two p–n junctions between two semiconductor types, n-type and p-type, which are regions in a single crystal of material. The junctions can be made in several different ways, such as changing the doping of the semiconductor material as it is grown, by depositing metal pellets to form alloy junctions, or by such methods as diffusion of n-type and p-type doping substances into the crystal. The superior predictability and performance of junction transistors quickly displaced the original point-contact transistor. Diffused transistors, alo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Germanium
Germanium is a chemical element with the symbol Ge and atomic number 32. It is lustrous, hard-brittle, grayish-white and similar in appearance to silicon. It is a metalloid in the carbon group that is chemically similar to its group neighbors silicon and tin. Like silicon, germanium naturally reacts and forms complexes with oxygen in nature. Because it seldom appears in high concentration, germanium was discovered comparatively late in the discovery of the elements. Germanium ranks near fiftieth in relative abundance of the elements in the Earth's crust. In 1869, Dmitri Mendeleev predicted its existence and some of its properties from its position on his periodic table, and called the element ekasilicon. In 1886, Clemens Winkler at Freiberg University found the new element, along with silver and sulfur, in the mineral argyrodite. Winkler named the element after his country, Germany. Germanium is mined primarily from sphalerite (the primary ore of zinc), though germani ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radio Shack
RadioShack, formerly RadioShack Corporation, is an American retailer founded in 1921. At its peak in 1999, RadioShack operated over 8,000 worldwide stores named RadioShack or Tandy Electronics in the United States, Mexico, United Kingdom, Australia, and Canada. Outside of those territories, the company licensed other companies to use the RadioShack brand name in parts of Asia, North Africa, Latin America, and the Caribbean. In February 2015, RadioShack Corporation filed for Chapter 11 protection under United States bankruptcy law after 11 consecutive quarterly losses. By then, it was operating only in the United States and Latin America. In May 2015, General Wireless Inc., an affiliate of Standard General, bought the company's assets, including the RadioShack brand name and related intellectual property, for US$26.2 million. General Wireless Operations Inc. was formed to operate the RadioShack stores, and General Wireless IP Holdings LLC was formed to hold the intellectual p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1950's Raytheon Transistor Applications For Experimenters And Hobbyist
Year 195 ( CXCV) was a common year starting on Wednesday (link will display the full calendar) of the Julian calendar. At the time, it was known as the Year of the Consulship of Scrapula and Clemens (or, less frequently, year 948 ''Ab urbe condita''). The denomination 195 for this year has been used since the early medieval period, when the Anno Domini calendar era became the prevalent method in Europe for naming years. Events By place Roman Empire * Emperor Septimius Severus has the Roman Senate deify the previous emperor Commodus, in an attempt to gain favor with the family of Marcus Aurelius. * King Vologases V and other eastern princes support the claims of Pescennius Niger. The Roman province of Mesopotamia rises in revolt with Parthian support. Severus marches to Mesopotamia to battle the Parthians. * The Roman province of Syria is divided and the role of Antioch is diminished. The Romans annexed the Syrian cities of Edessa and Nisibis. Severus re-establish his head ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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