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R-390A
The R-390A /URR is a general coverage HF radio communications receiver designed by Collins Radio Company for the United States Armed Forces. History The R-390A military shortwave radio receiver was the result of a project undertaken by the United States Army Signal Corps in 1954 to replace the existing R-390 receiver then in use. The R-390 had done its job so well that the Corps decided continued use of this type of receiver necessitated an improved, reduced-cost version. There are many references to the R390A in the open literature during this period; a picture of the receiver appeared in the May 1959 issue of ''QST''. The total production of the R-390A (as determined by the high serial numbers noted) is over 55,000 units. Initial production started in 1955 and ran through approximately 1970, and then was restarted in 1984 by Fowler Industries for Avondale Shipyards. Manufacturers and their approximate production numbers are: Companies which made spare modules, but not whole s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rockwell Collins
Rockwell Collins was a multinational corporation headquartered in Cedar Rapids, Iowa, providing avionics and information technology systems and services to government agencies and aircraft manufacturers. It was formed when the Collins Radio Company, facing financial difficulties, was purchased by Rockwell International in 1973. In 2001, the avionics division of Rockwell International was spun off to form the current Rockwell Collins, Inc, retaining its name. The company was acquired by United Technologies Corporation on November 27, 2018, and now operates as part of Collins Aerospace, a subsidiary of Raytheon Technologies. History Arthur A. Collins founded Collins Radio Company in 1933 in Cedar Rapids, Iowa. It designed and produced both shortwave radio equipment and equipment for the burgeoning AM radio broadcast industry. Collins was solicited by the military, the scientific community, and the larger AM radio stations for special equipment. Collins supplied the equipment t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Collins Radio Company
Rockwell Collins was a multinational corporation headquartered in Cedar Rapids, Iowa, providing avionics and information technology systems and services to government agencies and aircraft manufacturers. It was formed when the Collins Radio Company, facing financial difficulties, was purchased by Rockwell International in 1973. In 2001, the avionics division of Rockwell International was spun off to form the current Rockwell Collins, Inc, retaining its name. The company was acquired by United Technologies Corporation on November 27, 2018, and now operates as part of Collins Aerospace, a subsidiary of Raytheon Technologies. History Arthur A. Collins founded Collins Radio Company in 1933 in Cedar Rapids, Iowa. It designed and produced both shortwave radio equipment and equipment for the burgeoning AM radio broadcast industry. Collins was solicited by the military, the scientific community, and the larger AM radio stations for special equipment. Collins supplied the equipment t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shortwave Radio Receiver
A shortwave radio receiver is a radio receiver that can receive one or more shortwave bands, between 1.6 and 30 MHz. A shortwave radio receiver often receives other broadcast bands, such as FM radio, Longwave and Mediumwave. Shortwave radio receivers are often used by dedicated hobbyists called shortwave listeners. History While home built shortwave receivers had been used by amateur radio operators and radio experimenters prior to World War I, the first time shortwave radio reception was available to the general public was through the use of shortwave frequency converters sold as accessories to broadcast-band radio sets during the mid 1920s. Such converters were generally found unsatisfactory in performance, and so dedicated shortwave receiving sets soon appeared on the market. National Radio Company introduced the SW-2 "Thrill box" shortwave regenerative receiver in 1927, and later offered improved models, such as the highly regarded SW-3. Other notable early shortwave r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Communications Receiver
A communications receiver is a type of radio receiver used as a component of a radio communication link. This is in contrast to a ''broadcast receiver'' which is used to receive radio broadcasts. A communication receiver receives parts of the radio spectrum not used for broadcasting, that includes amateur, military, aircraft, marine, and other bands. They are often used with a radio transmitter as part of a two-way radio link for shortwave radio or amateur radio communication, although they are also used for shortwave listening. Features Commercial communications receivers are characterized by high stability and reliability of performance, and are generally adapted for remote control and monitoring. For marketing purposes, many hobby-type receivers are advertised as "communications receivers" although none are suited for heavy-duty, reliable 24-hour use as the primary form of communication for an isolated station. Typically, a communications receiver is of the superheterody ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
6AK5
The 6AK5 vacuum tube is a miniature 7-pin sharp-cutoff pentode used as RF or IF amplifier especially in high-frequency wide-band applications at frequencies up to 400 MHz. It was developed by Bell Labs / Western Electric and used extensively as an I.F. amplifier in World War II radar systems. The tube is notable for its extremely fine grid, and extremely close control grid to cathode spacing, yielding excellent high-frequency performance. It is also known as EF95 under its Mullard–Phillips designation and was produced in the former Soviet Union as type 6Zh1P (Russian: 6Ж1П) under the Russian designation system. A version of this tube with extended ratings was designated 6AK5W and 6Zh1P-EV (Russian: 6Ж1П-ЕВ) respectively. Even though primarily intended for VHF amplification, the tube has found some use in audio applications as a microphone preamplifier, for instance in the LOMO 19A9 microphone and in guitar effects stompboxes, such as Metasonix TM-7 Scrotum Smasher. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
12AU7
The 12AU7 and its variants are miniature nine-pin (B9A base) medium-gain dual triode vacuum tubes. It belongs to a large family of dual triode vacuum tubes which share the same pinout (RETMA tube designation, RETMA 9A). 12AU7 is also known in Europe under its Mullard–Philips tube designation ECC82. There are many equivalent tubes with different names, some identical, some designed for ruggedness, long life, or other characteristics; examples are the US military 5814A and the European special-quality ECC82 and E182CC. The tube is popular in hi-fi vacuum tube audio as a low-noise line amplifier, driver (especially for tone stacks), and phase-inverter in vacuum tube push–pull amplifier circuits. It was widely used, in special-quality versions such as ECC82 and 5814A, in pre-semiconductor digital computer circuitry. Use of special-quality versions outside of the purpose they were designed for may not be optimal; for example, a version for digital computers may be designed for lo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Triode
A triode is an electronic amplifying vacuum tube (or ''valve'' in British English) consisting of three electrodes inside an evacuated glass envelope: a heated filament or cathode, a grid, and a plate (anode). Developed from Lee De Forest's 1906 Audion, a partial vacuum tube that added a grid electrode to the thermionic diode (Fleming valve), the triode was the first practical electronic amplifier and the ancestor of other types of vacuum tubes such as the tetrode and pentode. Its invention founded the electronics age, making possible amplified radio technology and long-distance telephony. Triodes were widely used in consumer electronics devices such as radios and televisions until the 1970s, when transistors replaced them. Today, their main remaining use is in high-power RF amplifiers in radio transmitters and industrial RF heating devices. In recent years there has been a resurgence in demand for low power triodes due to renewed interest in tube-type audio systems by audiophi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rectifier
A rectifier is an electrical device that converts alternating current (AC), which periodically reverses direction, to direct current (DC), which flows in only one direction. The reverse operation (converting DC to AC) is performed by an Power inverter, inverter. The process is known as ''rectification'', since it "straightens" the direction of current. Physically, rectifiers take a number of forms, including Vacuum tube#Diodes, vacuum tube diodes, wet chemical cells, mercury-arc valves, stacks of copper and selenium rectifier, selenium oxide plates, Diode#Semiconductor diodes, semiconductor diodes, silicon-controlled rectifiers and other silicon-based semiconductor switches. Historically, even synchronous electromechanical switches and motor-generator sets have been used. Early radio receivers, called crystal radios, used a "Cat's-whisker detector, cat's whisker" of fine wire pressing on a crystal of galena (lead sulfide) to serve as a point-contact rectifier or "crystal detec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vacuum Tube
A vacuum tube, electron tube, valve (British usage), or tube (North America), is a device that controls electric current flow in a high vacuum between electrodes to which an electric voltage, potential difference has been applied. The type known as a thermionic tube or thermionic valve utilizes thermionic emission of electrons from a hot cathode for fundamental electronic functions such as signal amplifier, amplification and current rectifier, rectification. Non-thermionic types such as a vacuum phototube, however, achieve electron emission through the photoelectric effect, and are used for such purposes as the detection of light intensities. In both types, the electrons are accelerated from the cathode to the anode by the electric field in the tube. The simplest vacuum tube, the diode (i.e. Fleming valve), invented in 1904 by John Ambrose Fleming, contains only a heated electron-emitting cathode and an anode. Electrons can only flow in one direction through the device—fro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Joint Electronics Type Designation System
The Joint Electronics Type Designation System (JETDS), which was previously known as the Joint Army-Navy Nomenclature System (AN System. JAN) and the Joint Communications-Electronics Nomenclature System, is a method developed by the U.S. War Department during World War II for assigning an unclassified designator to electronic equipment. In 1957, the JETDS was formalized in MIL-STD-196. Computer software and commercial unmodified electronics for which the manufacturer maintains design control are not covered. Applicability Electronic material, from a military point of view, generally includes those electronic devices employed in data processing, detection and tracking (underwater, sea, land-based, air and space), recognition and identification, communications, aids to navigation, weapons control and evaluation, flight control, and electronics countermeasures. Nomenclature is assigned to: * Electronic materiel of military design * Commercial electronic materiel that has been modifi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
19-inch Rack
A 19-inch rack is a standardized frame or enclosure for mounting multiple electronic equipment modules. Each module has a front panel that is wide. The 19 inch dimension includes the edges or "ears" that protrude from each side of the equipment, allowing the module to be fastened to the rack frame with screws or bolts. Common uses include computer servers, telecommunications equipment and networking hardware, audiovisual production gear, and scientific equipment. Overview and history Equipment designed to be placed in a rack is typically described as rack-mount, rack-mount instrument, a rack-mounted system, a rack-mount chassis, subrack, rack cabinet, rack-mountable, or occasionally simply shelf. The height of the electronic modules is also standardized as multiples of or one rack unit or U (less commonly RU). The industry-standard rack cabinet is 42U tall; however, 45U racks are also common. The term ''relay rack'' appeared first in the world of telephony. By 1911, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Vacuum Tubes
This is a list of vacuum tubes or ''thermionic valves'', and low-pressure gas-filled tubes, or ''discharge tubes''. Before the advent of semiconductor devices, thousands of tube types were used in consumer electronics. Many industrial, military or otherwise professional tubes were also produced. Only a few types are still used today, mainly in high-power, high-frequency applications. Heater or filament ratings Receiving tubes have heaters or filaments intended for direct battery operation, parallel operation off a dedicated winding on a supply transformer, or series string operation on transformer-less sets. High-power RF power tubes are directly heated; the heater voltage must be much smaller than the signal voltage on the grid and is therefore in the 5...25 V range, drawing up to hundreds of amperes from a suitable heater transformer. In some valve part number series, the voltage class of the heater is given in the part number, and a similar valve might be available with s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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