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Two-way Radio
A two-way radio is a radio transceiver (a radio that can both transmit and receive radio waves), which is used for bidirectional person-to-person voice communication with other users with similar radios, in contrast to a broadcast receiver, which only receives transmissions. Two-way radios usually use a half-duplex communication channel, which permits two-way communication, albeit with the limitation that only one user can transmit at a time. (This is in contrast to simplex communication, in which transmission can only be sent in one direction, and full-duplex, which allows transmission in both directions simultaneously.) This requires users in a group to take turns talking. The radio is normally in receive mode so the user can hear all other transmissions on the channel. When the user wants to talk, they press a " push-to-talk" button, which turns off the receiver and turns on the transmitter; when the button is released, the receiver is activated again. Multiple channels are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Motorola
Motorola, Inc. () was an American multinational telecommunications company based in Schaumburg, Illinois. It was founded by brothers Paul and Joseph Galvin in 1928 and had been named Motorola since 1947. Many of Motorola's products had been radio-related communication equipment such as two-way radios, consumer walkie-talkies, cellular infrastructure, mobile phones, satellite communicators, pagers, as well as cable modems and semiconductors. After having lost $4.3 billion from 2007 to 2009, Motorola was split into two independent public companies: Motorola Solutions (its legal successor) and Motorola Mobility (spun off), on January 4, 2011. Motorola designed and sold wireless network equipment such as cellular transmission base stations and signal amplifiers. Its business and government customers consisted mainly of wireless voice and broadband systems (used to build private networks), and public safety communications systems like Astro and Dimetra. Motorola's h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cominco
The Consolidated Mining and Smelting Company of Canada Limited, and from 1966 onwards Cominco Ltd., was a Canadian mining company that existed from 1906 to 2001. Cominco was created by the Canadian Pacific Railway through the consolidation of a number of mining, smelting, and power assets in the British Columbia Interior. At its inception, the company's main asset was the Trail smelter, which serviced a variety of mines in the region. Sulphur dioxide pollution from the smelter, which crossed into the United States, became a major problem and led to an international tribunal in 1927 to remedy the situation. Cominco grew through the 1910s and 1920s, and by 1930s had become a major industrial concern. Besides its metals production, the company diversified into chemicals and fertilizers. In both world wars, Cominco was a major supplier of raw materials to the Canadian and British governments. Cominco grew to became an international mining company and one of the world's largest zinc pro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Order Of Canada
The Order of Canada () is a Canadian state order, national order and the second-highest Award, honour for merit in the system of orders, decorations, and medals of Canada, after the Order of Merit. To coincide with the Canadian Centennial, centennial of Canadian Confederation, the three-tiered order was established in 1967 as a fellowship recognizing the outstanding merit or distinguished service of Canadians who make a major difference to Canada through lifelong contributions in every field of endeavour, as well as efforts by non-Canadians who have made the world better by their actions. Membership is accorded to those who exemplify the order's Latin motto, , meaning "they desire a better country", a phrase taken from Hebrews 11:16. The three tiers of the order are Companion, Officer and Member. Specific people may be given extraordinary membership and deserving non-Canadians may receive honorary appointment into each grade. , the reigning Canadian monarch, is the order's sov ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
The Vancouver Sun
The ''Vancouver Sun'', also known as the ''Sun'', is a daily broadsheet newspaper based in Vancouver, British Columbia, Canada. The newspaper is currently published by the Pacific Newspaper Group, a division of Postmedia Network, and is the largest newspaper in western Canada by circulation. Since 2022, it is published five days a week from Tuesday to Saturday. The newspaper was first published on 12 February 1912. It quickly expanded by acquiring other papers, such as the ''Daily News-Advertiser'' and ''Vancouver World, The Evening World''. In 1963, the Cromie family sold the majority of its holdings in the ''Sun'' to FP Publications, who later sold the newspaper to Southam Inc. in 1980. The newspaper was taken over by Hollinger Inc. in 1992, and was later sold again to CanWest in 2000. In 2010, the newspaper became part of the Postmedia Network as a result of the collapse of CanWest. History The ''Vancouver Sun'' published its first edition on 12 February 1912. The newspape ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Joan-Eleanor System
The Joan-Eleanor system (or J-E for short) was a clandestine very high frequency (VHF) radio system developed by the United States OSS during World War II for use by espionage agents working behind enemy lines to relay information and replaced the earlier S-Phone system developed by the SOE. Design and development The Joan-Eleanor system was developed from late 1942 onwards for the US Office of Strategic Services (OSS) by DeWitt R. Goddard and Lt. Cmdr. Stephen H. Simpson, with some contributions from mobile radio pioneer Alfred J. Gross. It is said to have been named for Goddard's wife Eleanor, and a WAC Major of Simpson's acquaintance named Joan Marshall. The initial design work was performed at RCA's laboratories in Riverhead, New York, and the production units produced by Citizens Radio of Cleveland, Freed Radio Corporation of New York City, Dictagraph Corporation of New York, and the Signal-U Manufacturing Company. Most of the testing was carried out in the United St ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Donald Hings
Donald Lewes Hings, (November 6, 1907 – February 25, 2004) was a British-Canadian inventor, born in Leicester, England. In 1937 he created a portable radio signaling system for his employer CM&S, which he called a "packset", but which later became known as the "Walkie-Talkie". While Hings was filing a U.S. patent for the packset in Spokane, Washington in 1939, Canada declared war on Germany. CM&S sent Hings to Ottawa to redevelop his new invention for military use, and he worked there from 1940 to 1945. During these years, he developed a number of models, including the successful C-58 Walkie-Talkie which eventually sold eighteen thousand units produced for infantry use, and for which he received the MBE in 1946 and the Order Of Canada in 2001. Following the war, he moved to Burnaby, British Columbia, where he established an electronics R&D company, Electronic Labs of Canada. He continued researching and creating in the fields of communications and geophysics until his ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SCR-300
The SCR-300, designated AN/VRC-3 under the Joint Electronics Type Designation System, was a portable frequency modulated (FM) radio transceiver used by US Signal Corps in World War II. This backpack-mounted unit was the first radio to be nicknamed a " walkie talkie". History In 1940, Motorola (then the Galvin Manufacturing Company) received a contract from the War Department to develop a portable, battery powered voice radio receiver/transmitter for field use by infantry units. The project engineering team consisted of Daniel E. Noble, who conceived of the design using frequency modulation, Henryk Magnuski who was the principal RF engineer, Marion Bond, Lloyd Morris, and Bill Vogel. The SCR-300 operated in the 40.0 to 48.0 MHz (megahertz) frequency range, and was channelized. Along with other mobile FM tank and artillery radios such as the SCR-508 (20.0 to 27.9 MHz) and the SCR-608 (27.0 to 38.9 MHz), the SCR-300 marked the beginning of the transition of combat-net ra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Frequency Modulation
Frequency modulation (FM) is a signal modulation technique used in electronic communication, originally for transmitting messages with a radio wave. In frequency modulation a carrier wave is varied in its instantaneous frequency in proportion to a property, primarily the instantaneous amplitude, of a message signal, such as an audio signal. The technology is used in telecommunications, radio broadcasting, signal processing, and Run-length limited#FM: .280.2C1.29 RLL, computing. In Analog signal, analog frequency modulation, such as radio broadcasting of voice and music, the instantaneous frequency deviation, i.e. the difference between the frequency of the carrier and its center frequency, has a functional relation to the modulating signal amplitude. Digital data can be encoded and transmitted with a type of frequency modulation known as frequency-shift keying (FSK), in which the instantaneous frequency of the carrier is shifted among a set of frequencies. The frequencies m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
