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A-7 (transceiver)
The Soviet A-7 VHF radio transceiver (later models include the A-7a and A-7b) was developed during World War II and used for communication in rifle brigades and regiments. The complete station was designed to be transported by an individual soldier. Design and features A-7 The A-7 is a portable man-pack, radio transceiver with narrow-band frequency modulation. The set can be used as a radio telephone in a wired network and managed remotely. Setting the frequency of the receiver and transmitter circuits is adjusted in tandem by one control handle. The antenna and buffer oscillator circuits are common for the receiving and transmitting circuits. The receiver section is a superheterodyne design with a single frequency conversion, consisting of 8 identical 2K2M valves. A regenerative detector with adjustable feedback is used. The transmitter section includes a 2K2M modulator valve, a CO-257 buffer amplifier valve, and a CO-257 power amplifier valve. Switching from reception to tra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
World War II
World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the World War II by country, vast majority of the world's countries—including all of the great powers—forming two opposing military alliances: the Allies of World War II, Allies and the Axis powers. World War II was a total war that directly involved more than 100 million Military personnel, personnel from more than 30 countries. The major participants in the war threw their entire economic, industrial, and scientific capabilities behind the war effort, blurring the distinction between civilian and military resources. Air warfare of World War II, Aircraft played a major role in the conflict, enabling the strategic bombing of population centres and deploying the Atomic bombings of Hiroshima and Nagasaki, only two nuclear weapons ever used in war. World War II was by far the List of wars by death toll, deadliest conflict in hu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Superheterodyne
A superheterodyne receiver, often shortened to superhet, is a type of radio receiver that uses frequency mixing to convert a received signal to a fixed intermediate frequency (IF) which can be more conveniently processed than the original carrier frequency. It was long believed to have been invented by US engineer Edwin Armstrong, but after some controversy the earliest patent for the invention is now credited to French radio engineer and radio manufacturer Lucien Lévy. Virtually all modern radio receivers use the superheterodyne principle; except those software-defined radios using ''direct sampling''. History Heterodyne Early Morse code radio broadcasts were produced using an alternator connected to a spark gap. The output signal was at a carrier frequency defined by the physical construction of the gap, modulated by the alternating current signal from the alternator. Since the output frequency of the alternator was generally in the audible range, this produces an audible a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vacuum Tubes
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 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 amplification and current 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—from the cathode to the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reflex Receiver
A reflex radio receiver, occasionally called a reflectional receiver, is a radio receiver design in which the same amplifier is used to amplify the high-frequency radio signal (RF) and low-frequency audio (sound) signal (AF). It was first invented in 1914 by German scientists Wilhelm Schloemilch and Otto von Bronk,US Patent no. 1087892, Wilhelm Schloemilch and Otto von Bronk Means for receiving electrical oscillations', filed March 14, 1913; granted February 17, 1914 and rediscovered and extended to multiple tubes in 1917 by Marius LatourUS Patent no. 1405523, Marius Latour Audion or lamp relay or amplifying apparatus', filed December 28, 1917; granted February 7, 1922 and William H. Priess. The radio signal from the antenna and tuned circuit passes through an amplifier, is demodulated in a detector which extracts the audio signal from the radio carrier, and the resulting audio signal passes ''again'' through the same amplifier for audio amplification before being applied to the e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tesla (Czechoslovak Company)
Tesla (stylized as TESLA) is a Czech brand of electronic appliances. The name was originally used by a state-owned conglomerate that was the monopoly producer of electronic appliances and components in the former Socialist Republic of Czechoslovakia. The conglomerate was founded in 1946 and ran until 1991, when it was privatised. The Tesla name is used by its successor company and former subsidiaries in the Czech Republic and Slovakia. Company The company was established as ''Elektra'' on 18 January 1921 and renamed Tesla on 7 March 1946. A founding ceremony took place on 10 August 1946 at the Mikrofon Factory in Strašnice attended by government ministers from Czechoslovakia, Yugoslavia and Macedonia. It was named after the pioneer scientist Nikola Tesla, but when the association with a Serbian American became politically inconvenient it was explained as abbreviation from , which means "low-current technology". Tesla had several production locations, including those at Li ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
World War II Military Equipment Of The Soviet Union
In its most general sense, the term "world" refers to the totality of entities, to the whole of reality or to everything that is. The nature of the world has been conceptualized differently in different fields. Some conceptions see the world as unique while others talk of a "plurality of worlds". Some treat the world as one simple object while others analyze the world as a complex made up of many parts. In ''scientific cosmology'' the world or universe is commonly defined as " e totality of all space and time; all that is, has been, and will be". '' Theories of modality'', on the other hand, talk of possible worlds as complete and consistent ways how things could have been. ''Phenomenology'', starting from the horizon of co-given objects present in the periphery of every experience, defines the world as the biggest horizon or the "horizon of all horizons". In ''philosophy of mind'', the world is commonly contrasted with the mind as that which is represented by the mind. ''Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Military Electronics Of Russia
A military, also known collectively as armed forces, is a heavily armed, highly organized force primarily intended for warfare. It is typically authorized and maintained by a sovereign state, with its members identifiable by their distinct military uniform. It may consist of one or more military branches such as an army, navy, air force, space force, marines, or coast guard. The main task of the military is usually defined as defence of the state and its interests against external armed threats. In broad usage, the terms ''armed forces'' and ''military'' are often treated as synonymous, although in technical usage a distinction is sometimes made in which a country's armed forces may include both its military and other paramilitary forces. There are various forms of irregular military forces, not belonging to a recognized state; though they share many attributes with regular military forces, they are less often referred to as simply ''military''. A nation's military may ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
