|
B9A
A magic eye tube or tuning indicator, in technical literature called an electron-ray indicator tube, is a vacuum tube which gives a visual indication of the amplitude of an electronic signal, such as an audio output, radio-frequency signal strength, or other functions. The magic eye (also called a cat's eye, or tuning eye in North America) is a specific type of such a tube with a circular display similar to the EM34 illustrated. Its first broad application was as a tuning indicator in radio receivers, to give an indication of the relative strength of the received radio signal, to show when a radio station was properly tuned in. The magic eye tube was the first in a line of development of cathode ray type tuning indicators developed as a cheaper alternative to needle movement meters. It was not until the 1960s that needle meters were made inexpensively enough in Japan to displace indicator tubes. Tuning indicator tubes were used in vacuum tube receivers from around 1936 to 1980, b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Automatic Gain Control
Automatic gain control (AGC) is a closed-loop feedback regulating circuit in an amplifier or chain of amplifiers, the purpose of which is to maintain a suitable signal amplitude at its output, despite variation of the signal amplitude at the input. The average or peak output signal level is used to dynamically adjust the gain of the amplifiers, enabling the circuit to work satisfactorily with a greater range of input signal levels. It is used in most radio receivers to equalize the average volume ( loudness) of different radio stations due to differences in received signal strength, as well as variations in a single station's radio signal due to fading. Without AGC the sound emitted from an AM radio receiver would vary to an extreme extent from a weak to a strong signal; the AGC effectively reduces the volume if the signal is strong and raises it when it is weaker. In a typical receiver the AGC feedback control signal is usually taken from the detector stage and applied t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
S Meter
An S meter (signal strength meter) is an indicator often provided on communications receivers, such as amateur radio or shortwave broadcast receivers. The scale markings are derived from a system of reporting signal strength from S1 to S9 as part of the R-S-T system. The term S unit refers to the amount of signal strength required to move an S meter indication from one marking to the next. Technical description Analogue S meters are actually sensitive microammeters, with a full scale deflection of 50 to 100 μA. In AM receivers, the S meter can be connected to the main detector or use a separate detector at the final intermediate frequency, IF stage. This is the preferred method for continuous wave, CW and single sideband, SSB receivers. Another approach in the days of electronic tubes (valves) was to connect the S meter to the screen grid circuit of the final IF amplifier tube. A third option is to connect the S meter to the automatic gain control, AGC line through a suitable ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Circuital (album)
''Circuital'' is the sixth studio album by American rock band My Morning Jacket. It was released on May 31, 2011. The album received mainly positive reviews and sold 55,000 copies in the first week of release. It debuted at number 5 on the ''Billboard'' 200, improving on the band's previous highest debuting album ''Evil Urges'', which entered the chart at number 9. This album peaked at 1 on the independent albums chart, 3 on the rock albums, and 3 on the alternative albums charts. The album has sold 208,000 copies in the US as of April 2015. The album was also released as a double 12" 45 RPM vinyl set and as a deluxe vinyl edition. As promotion for the album, the band gave away one free download per week for six weeks until April 12. The first five tracks were recorded during their shows at New York's Terminal 5 in October 2010, while the final download was the new album's title track. Songs All tracks were recorded in the band's hometown of Louisville, Kentucky in a church gy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
My Morning Jacket
My Morning Jacket is an American Rock music, rock band formed in Louisville, Kentucky, in 1998. The band consists of vocalist/guitarist Jim James, bassist Tom Blankenship, drummer Patrick Hallahan, guitarist Carl Broemel, and keyboardist Bo Koster. The band's sound, rooted in rock and country, is often experimental and psychedelic. The group amassed a following beginning in the 2000s in part due to their live performances. The group first found success in Europe after the release of its debut album, ''The Tennessee Fire'' (1999). Its next release, ''At Dawn'' (2001), led to a large stateside following and preceded several lineup changes. After signing to major label ATO Records, the group released two albums, ''It Still Moves'' (2003) and ''Z (My Morning Jacket album), Z'' (2005), with the latter representing a critical breakthrough. The group's next release, ''Evil Urges'' (2008), was more polarizing for fans and critics, while ''Circuital'' (2011), its sixth album, saw a more ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Capacitance Meter
A capacitance meter is a piece of electronic test equipment used to measure capacitance, mainly of discrete capacitors. Depending on the sophistication of the meter, it may display the capacitance only, or it may also measure a number of other parameters such as Leakage (electronics), leakage, equivalent series resistance (ESR), and inductance. For most purposes and in most cases the capacitor must be disconnected from electronic circuit, circuit; ESR can usually be measured in circuit. Simple checks without a true capacitance meter Some checks can be made without a specialised instrument, particularly on aluminium electrolytic capacitors which tend to be of high capacitance and to be subject to poor leakage. A multimeter in a resistance range can detect a short-circuited capacitor (very low resistance) or one with very high leakage (high resistance, but lower than it should be; an ideal capacitor has infinite DC resistance). A crude idea of the capacitance can be derived with a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Voltmeter
A voltmeter is an instrument used for measuring electric potential difference between two points in an electric circuit. It is connected in parallel. It usually has a high resistance so that it takes negligible current from the circuit. Analog voltmeters move a pointer across a scale in proportion to the voltage measured and can be built from a galvanometer and series resistor. Meters using amplifiers can measure tiny voltages of microvolts or less. Digital voltmeters give a numerical display of voltage by use of an analog-to-digital converter. Voltmeters are made in a wide range of styles, some separately powered (e.g. by battery), and others powered by the measured voltage source itself. Instruments permanently mounted in a panel are used to monitor generators or other fixed apparatus. Portable instruments, usually equipped to also measure current and resistance in the form of a multimeter are standard test instruments used in electrical and electronics work. Any meas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Linearity
In mathematics, the term ''linear'' is used in two distinct senses for two different properties: * linearity of a '' function'' (or '' mapping''); * linearity of a '' polynomial''. An example of a linear function is the function defined by f(x)=(ax,bx) that maps the real line to a line in the Euclidean plane R2 that passes through the origin. An example of a linear polynomial in the variables X, Y and Z is aX+bY+cZ+d. Linearity of a mapping is closely related to '' proportionality''. Examples in physics include the linear relationship of voltage and current in an electrical conductor ( Ohm's law), and the relationship of mass and weight. By contrast, more complicated relationships, such as between velocity and kinetic energy, are '' nonlinear''. Generalized for functions in more than one dimension, linearity means the property of a function of being compatible with addition and scaling, also known as the superposition principle. Linearity of a polynomial means that it ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lissajous Figure
A Lissajous curve , also known as Lissajous figure or Bowditch curve , is the graph of a system of parametric equations : x=A\sin(at+\delta),\quad y=B\sin(bt), which describe the superposition of two perpendicular oscillations in x and y directions of different angular frequency (''a'' and ''b).'' The resulting family of curves was investigated by Nathaniel Bowditch in 1815, and later in more detail in 1857 by Jules Antoine Lissajous (for whom it has been named). Such motions may be considered as a particular kind of complex harmonic motion. The appearance of the figure is sensitive to the ratio . For a ratio of 1, when the frequencies match a=b, the figure is an ellipse, with special cases including circles (, radians) and line (mathematics), lines (). A small change to one of the frequencies will mean the x oscillation after one cycle will be slightly out of synchronization with the y motion and so the ellipse will fail to close and trace a curve slightly adjacent during the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tape Recorder
An audio tape recorder, also known as a tape deck, tape player or tape machine or simply a tape recorder, is a sound recording and reproduction device that records and plays back sounds usually using magnetic tape for storage. In its present-day form, it records a fluctuating signal by moving the tape across a tape head that polarizes the magnetic domains in the tape in proportion to the audio signal. Tape-recording devices include the reel-to-reel tape deck and the cassette deck, which uses a cassette tape (format), cassette for storage. The use of magnetic tape for sound recording originated around 1930 in Germany as paper tape with oxide lacquered to it. Prior to the development of magnetic tape, magnetic wire recording, wire recorders had successfully demonstrated the concept of magnetic recording, but they never offered audio quality comparable to the other recording and broadcast standards of the time. This German invention was the start of a long string of innovations ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zenith Radio
Zenith Electronics, LLC, is an American research and development company that develops ATSC and digital rights management technologies. It is owned by the South Korean company LG Electronics. Zenith was previously an American brand of consumer electronics, a manufacturer of radio and television receivers and other consumer electronics, and was headquartered in Glenview, Illinois. After a series of layoffs, the consolidated headquarters moved to Lincolnshire, Illinois. For many years, their famous slogan (borrowed from Crown Piano maker George Bent of Chicago, used through the 1890s) was "The quality goes in before the name goes on". LG Electronics acquired a controlling share of Zenith in 1995; Zenith became a wholly owned subsidiary in 1999. Zenith was the inventor of subscription television and the modern remote control, and was the first to develop high-definition television (HDTV) in North America. Zenith-branded products were sold in North America, Germany, Thailand (to 1983 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stereo
Stereophonic sound, commonly shortened to stereo, is a method of sound reproduction that recreates a multi-directional, 3-dimensional audible perspective. This is usually achieved by using two independent audio channels through a configuration of two loudspeakers (or stereo headphones) in such a way as to create the impression of sound heard from various directions, as in natural hearing. Because the multi-dimensional perspective is the crucial aspect, the term ''stereophonic'' also applies to systems with more than two channels or speakers such as quadraphonic and surround sound. Binaural sound systems are also ''stereophonic''. Stereo sound has been in common use since the 1970s in entertainment media such as broadcast radio, recorded music, television, video cameras, cinema, computer audio, and the Internet. Etymology The word ''stereophonic'' derives from the Greek (''stereós'', "firm, solid") + (''phōnḗ'', "sound, tone, voice") and it was coined in 1927 by ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
