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Octode
The pentagrid converter is a type of radio receiving valve (vacuum tube) with five grids used as the frequency mixer stage of a superheterodyne radio receiver. The pentagrid was part of a line of development of valves that were able to take an incoming RF signal and change its frequency to a fixed intermediate frequency, which was then amplified and detected in the remainder of the receiver circuitry. The device was generically referred to as a ''frequency changer'' or just ''mixer''. Origins The first devices designed to change frequency in the manner described above seem to have been developed by the French, who simply put two grids into what would otherwise have been an ordinary triode valve (the bi-grille or bi-grid). Although technically a four electrode device, neither the term tetrode nor the tetrode valve as it is known today had yet appeared. The bi-grid differed from the later tetrode because the second (outer) grid was coarsely wound compared with the tetrode's sc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heptode Pentagrid
The pentagrid converter is a type of radio receiving valve (vacuum tube) with five grids used as the frequency mixer stage of a superheterodyne radio receiver. The pentagrid was part of a line of development of valves that were able to take an incoming RF signal and change its frequency to a fixed intermediate frequency, which was then amplified and detected in the remainder of the receiver circuitry. The device was generically referred to as a ''frequency changer'' or just ''mixer''. Origins The first devices designed to change frequency in the manner described above seem to have been developed by the French, who simply put two grids into what would otherwise have been an ordinary triode valve (the bi-grille or bi-grid). Although technically a four electrode device, neither the term tetrode nor the tetrode valve as it is known today had yet appeared. The bi-grid differed from the later tetrode because the second (outer) grid was coarsely wound compared with the tetrode's scr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hexode Symbol
The pentagrid converter is a type of radio receiving valve (vacuum tube) with five grids used as the frequency mixer stage of a superheterodyne radio receiver. The pentagrid was part of a line of development of valves that were able to take an incoming RF signal and change its frequency to a fixed intermediate frequency, which was then amplified and detected in the remainder of the receiver circuitry. The device was generically referred to as a ''frequency changer'' or just ''mixer''. Origins The first devices designed to change frequency in the manner described above seem to have been developed by the French, who simply put two grids into what would otherwise have been an ordinary triode valve (the bi-grille or bi-grid). Although technically a four electrode device, neither the term tetrode nor the tetrode valve as it is known today had yet appeared. The bi-grid differed from the later tetrode because the second (outer) grid was coarsely wound compared with the tetrode's scr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heptode
The pentagrid converter is a type of radio receiving valve (vacuum tube) with five grids used as the frequency mixer stage of a superheterodyne radio receiver. The pentagrid was part of a line of development of valves that were able to take an incoming RF signal and change its frequency to a fixed intermediate frequency, which was then amplified and detected in the remainder of the receiver circuitry. The device was generically referred to as a ''frequency changer'' or just ''mixer''. Origins The first devices designed to change frequency in the manner described above seem to have been developed by the French, who simply put two grids into what would otherwise have been an ordinary triode valve (the bi-grille or bi-grid). Although technically a four electrode device, neither the term tetrode nor the tetrode valve as it is known today had yet appeared. The bi-grid differed from the later tetrode because the second (outer) grid was coarsely wound compared with the tetrode's sc ... [...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 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] |
All American Five
The term All American Five (abbreviated AA5) is a colloquial name for mass-produced, superheterodyne radio receivers that used five vacuum tubes in their design. These radio sets were designed to receive amplitude modulation (AM) broadcasts in the medium wave band, and were manufactured in the United States from the mid-1930s until the early 1960s. By eliminating a power transformer, cost of the units was kept low; the same principle was later applied to television receivers. Variations in the design for lower cost, shortwave bands, better performance or special power supplies existed, although many sets used an identical set of vacuum tubes. Philosophy The radio was called the "All American Five" because the design typically used five vacuum tubes, and comprised the majority of radios manufactured for home use in the USA and Canada in the tube era. They were manufactured in the millions by hundreds of manufacturers from the 1930s onward, with the last examples being made in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Frequency Mixer
In electronics, a mixer, or frequency mixer, is an electrical circuit that creates new frequencies from two signals applied to it. In its most common application, two signals are applied to a mixer, and it produces new signals at the sum and difference of the original frequencies. Other frequency components may also be produced in a practical frequency mixer. Mixers are widely used to shift signals from one frequency range to another, a process known as heterodyning, for convenience in transmission or further signal processing. For example, a key component of a superheterodyne receiver is a mixer used to move received signals to a common intermediate frequency. Frequency mixers are also used to modulate a carrier signal in radio transmitters. Types The essential characteristic of a mixer is that it produces a component in its output which is the product of the two input signals. Both active and passive circuits can realize mixers. Passive mixers use one or more diodes and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pentode
A pentode is an electronic device having five electrodes. The term most commonly applies to a three-grid amplifying vacuum tube or thermionic valve that was invented by Gilles Holst and Bernhard D.H. Tellegen in 1926. The pentode (called a ''triple-grid amplifier'' in some literature) was developed from the ''screen-grid tube'' or ''shield-grid tube'' (a type of tetrode tube) by the addition of a grid between the screen grid and the plate. The screen-grid tube was limited in performance as an amplifier due to secondary emission of electrons from the plate. The additional grid is called the ''suppressor grid''. The suppressor grid is usually operated at or near the potential of the cathode and prevents secondary emission electrons from the plate from reaching the screen grid. The addition of the suppressor grid permits much greater output signal amplitude to be obtained from the plate of the pentode in amplifier operation than from the plate of the screen-grid tube at the same plat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transconductance
Transconductance (for transfer conductance), also infrequently called mutual conductance, is the electrical characteristic relating the current through the output of a device to the voltage across the input of a device. Conductance is the reciprocal of resistance. Transadmittance (or transfer admittance) is the AC equivalent of transconductance. Definition Transconductance is very often denoted as a conductance, ''g''m, with a subscript, m, for ''mutual''. It is defined as follows: :g_m = \frac For small signal alternating current, the definition is simpler: :g_m = \frac The SI unit for transconductance is the siemens, with the symbol S, as in conductance. Transresistance Transresistance (for transfer resistance), also infrequently referred to as mutual resistance, is the dual of transconductance. It refers to the ratio between a change of the voltage at two output points and a related change of current through two input points, and is notated as ''r''m: :r_m = \fra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Loctal Base
Tube sockets are electrical sockets into which vacuum tubes (electronic valves) can be plugged, holding them in place and providing terminals, which can be soldered into the circuit, for each of the pins. Sockets are designed to allow tubes to be inserted in only one orientation. They were used in most tube electronic equipment to allow easy removal and replacement. When tube equipment was common, retailers such as drug stores had vacuum tube testers, and sold replacement tubes. Some Nixie tubes were also designed to use sockets. Throughout the tube era, as technology developed, sometimes differently in different parts of the world, many tube bases and sockets came into use. Sockets are not universal; different tubes may fit mechanically into the same socket, though they may not work properly and possibly become damaged. Tube sockets were typically mounted in holes on a sheet metal chassis and wires or other components were hand soldered to lugs on the underside of the socket. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Philco
Philco (an acronym for Philadelphia Battery Company) is an American electronics industry, electronics manufacturer headquartered in Philadelphia. Philco was a pioneer in battery, radio, and television production. In 1961, the company was purchased by Ford Motor Company, Ford and, from 1966, renamed "Philco-Ford". Ford sold the company to GTE in 1974, and it was purchased by Philips in 1981. In North America, the Philco brand is currently owned by Philips. In other markets, the Philco International brand is owned by Electrolux. In the early 1920s, Philco made storage batteries, "socket power" battery eliminator units (plug-in transformers), and battery chargers. With the invention of the rectifier tube, which made it practical to power radios by electrical outlets, in 1928, Philco entered the radio business. They followed other radio makers such as RCA, Atwater-Kent, Zenith Electronics, Freshman Masterpiece, FADA Radio (Frank A. D'Andrea Radio), and AH Grebe into the battery-powere ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Osram Sylvania
Osram Sylvania Inc. is the North American operation of lighting manufacturer Osram Osram Licht AG is a German company that makes electric lights, headquartered in Munich and Premstätten (Austria). Osram positions itself as a high-tech photonics company that is increasingly focusing on sensor technology, visualization and t .... It was established in January 1993, with the acquisition of GTE’s Sylvania lighting division by Osram GmbH. In 2016, Osram spun off their general lighting business to Ledvance which received a license to sell lighting products under the Osram and Sylvania names. The company produces lighting products for industrial, entertainment, medical, and smart building and city applications, as well as products for the automotive aftermarket and original equipment manufacturer markets. Osram Sylvania completed a move of their regional headquarters from Danvers, Massachusetts, to Wilmington, Massachusetts, on 12 October 2015. Company profile Osram S ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mixer Oktode
Mixer may refer to: Electronics * DJ mixer, a type of audio mixing console used by disc jockeys * Electronic mixer, electrical circuit for adding signal voltages * Frequency mixer, electrical circuit that creates new frequencies from two signals applied to it * Mixing console, an electronic device for combining sounds of different audio signals * Mix engineer, person who combines elements of recorded music into a final version * Mode scrambler, known as a mode mixer, telecommunications device for inducing mode coupling in an optical fiber * Sound card mixer, analog part of a sound card that routes and mixes sound signals * Vision mixer, an electronic device for combining video signals Industrial and lab equipment * Concrete mixer, a machine which combines the ingredients of concrete, a.k.a. cement mixer * Feed mixer, for mixing feed ingredients * High-shear mixer, a device that disperse, or transports one phase or ingredient (liquid, solid, gas) into a main continuous phase ( ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
