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RG-59
RG-59/U is a specific type of coaxial cable, often used for low-power video and RF signal connections. The cable has a characteristic impedance of 75 ohms, and a capacitance of around 20pF/ft (60pF/m). The 75 ohm impedance matches a dipole antenna in free space. ''RG'' (for ''radio guide'') was originally a unit indicator for bulk radio frequency (RF) cable in the U.S. military's Joint Electronics Type Designation System. The suffix ''/U'' means ''for general utility use''. The number ''59'' was assigned sequentially. The ''RG'' unit indicator is no longer part of the JETDS system (MIL-STD-196E) and cable sold today under the RG-59 label does not necessarily meet military specifications. RG-59 is often used at baseband video frequencies, such as composite video. It may also be used for broadcast frequencies, but its high-frequency losses are too high to allow its use over long distances; in these applications, RG-6 or RG-11 are used instead. In cases where the transmi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coaxial Cable
Coaxial cable, or coax (pronounced ) is a type of electrical cable consisting of an inner conductor surrounded by a concentric conducting shield, with the two separated by a dielectric ( insulating material); many coaxial cables also have a protective outer sheath or jacket. The term '' coaxial'' refers to the inner conductor and the outer shield sharing a geometric axis. Coaxial cable is a type of transmission line, used to carry high-frequency electrical signals with low losses. It is used in such applications as telephone trunk lines, broadband internet networking cables, high-speed computer data busses, cable television signals, and connecting radio transmitters and receivers to their antennas. It differs from other shielded cables because the dimensions of the cable and connectors are controlled to give a precise, constant conductor spacing, which is needed for it to function efficiently as a transmission line. Coaxial cable was used in the first (1858) and follo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coaxial Cable
Coaxial cable, or coax (pronounced ) is a type of electrical cable consisting of an inner conductor surrounded by a concentric conducting shield, with the two separated by a dielectric ( insulating material); many coaxial cables also have a protective outer sheath or jacket. The term '' coaxial'' refers to the inner conductor and the outer shield sharing a geometric axis. Coaxial cable is a type of transmission line, used to carry high-frequency electrical signals with low losses. It is used in such applications as telephone trunk lines, broadband internet networking cables, high-speed computer data busses, cable television signals, and connecting radio transmitters and receivers to their antennas. It differs from other shielded cables because the dimensions of the cable and connectors are controlled to give a precise, constant conductor spacing, which is needed for it to function efficiently as a transmission line. Coaxial cable was used in the first (1858) and follo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
RG-59
RG-59/U is a specific type of coaxial cable, often used for low-power video and RF signal connections. The cable has a characteristic impedance of 75 ohms, and a capacitance of around 20pF/ft (60pF/m). The 75 ohm impedance matches a dipole antenna in free space. ''RG'' (for ''radio guide'') was originally a unit indicator for bulk radio frequency (RF) cable in the U.S. military's Joint Electronics Type Designation System. The suffix ''/U'' means ''for general utility use''. The number ''59'' was assigned sequentially. The ''RG'' unit indicator is no longer part of the JETDS system (MIL-STD-196E) and cable sold today under the RG-59 label does not necessarily meet military specifications. RG-59 is often used at baseband video frequencies, such as composite video. It may also be used for broadcast frequencies, but its high-frequency losses are too high to allow its use over long distances; in these applications, RG-6 or RG-11 are used instead. In cases where the transmi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
RG-58
RG-58/U is a type of coaxial cable often used for low-power signal and RF connections. The cable has a characteristic impedance of either 50 or 52 Ω. "RG" was originally a unit indicator for bulk RF cable in the U.S. military's Joint Electronics Type Designation System. There are several versions covering the differences in core material (solid or braided wire) and shield (70% to 95% coverage). The outside diameter of RG-58 is around 0.2 inches (5 mm). RG-58 weighs around 0.025 lb/ft (37 g/m), exhibits approximately 25 pF/ft (82 pF/m) capacitance and can tolerate a maximum of 300 V potential (1800 W). Plain RG-58 cable has a solid center conductor. The RG-58A/U features a flexible 7- or 19-strand center conductor. Most two-way radio communication systems, such as marine, CB radio, amateur, police, fire, WLAN antennas etc., are designed to work with a 50 Ω cable. RG-58 cable is often used as a generic carrier of signals in labo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
BNC Connector
The BNC connector (initialism of "Bayonet Neill–Concelman") is a miniature quick connect/disconnect radio frequency connector used for coaxial cable. It is designed to maintain the same characteristic impedance of the cable, with 50 ohm and 75 ohm types being made. It is usually applied for video and radio frequency connections up to about 2 GHz and up to 500 volts. The connector has a twist to lock design with two lugs in the female portion of the connector engaging a slot in the shell of the male portion. The type was introduced on military radio equipment in the 1940s and has since become widely applied in radio systems, and is a common type of video connector. Similar radio-frequency connectors differ in dimensions and attachment features, and may allow for higher voltages, higher frequencies, or three-wire connections. Description The BNC connector features two bayonet lugs on the female connector; mating is fully achieved with a quarter turn of the coupling nut. It us ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Word Clock
In digital audio electronics, a word clock or wordclock (sometimes sample clock, which can have a broader meaning) is a clock signal used to synchronise other devices, such as digital audio tape machines and compact disc players, which interconnect via digital audio signals. Word clock is so named because it clocks each audio sample. Samples are represented in data words. S/PDIF, AES/EBU, MADI, ADAT, and TDIF are some of the formats that use a word clock. Various audio over Ethernet systems use communication protocols to distribute word clock. The device which generates the word clock is the clock source for all the other audio devices. Comparison to timecode Word clock should not be confused with timecode; word clock is used entirely to keep a perfectly timed and constant bitrate to avoid timing errors that can cause data transmission errors. Timecode is metadata ''about'' the media data being transmitted. Time code can be used as an initial phase reference for jam s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ADAT
Alesis Digital Audio Tape (ADAT) is a magnetic tape format used for the recording of eight digital audio tracks onto the same S-VHS tape used by consumer VCRs. Although it is a tape-based format, the term ''ADAT'' now refers to its successor, the Alesis ADAT HD24, which features hard disk recording rather than the traditional tape-based ADAT, which in turn is now considered obsolete. History The product was announced in January 1991 at the NAMM convention in Anaheim, California by Alesis. The first ADAT recorders shipped over a year later in February or March 1992. More audio tracks could be recorded by synchronizing up to 16 ADAT machines together, for a total of 128 tracks. While synchronization had been available in earlier machines, ADAT machines were the first to do so with sample-accurate timing, which in effect allowed a studio owner to purchase a 24-track tape machine eight tracks at a time. This capability and its comparatively low cost, originally introduc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Digital Audio
Digital audio is a representation of sound recorded in, or converted into, digital form. In digital audio, the sound wave of the audio signal is typically encoded as numerical samples in a continuous sequence. For example, in CD audio, samples are taken 44,100 times per second, each with 16-bit sample depth. Digital audio is also the name for the entire technology of sound recording and reproduction using audio signals that have been encoded in digital form. Following significant advances in digital audio technology during the 1970s and 1980s, it gradually replaced analog audio technology in many areas of audio engineering, record production and telecommunications in the 1990s and 2000s In a digital audio system, an analog electrical signal representing the sound is converted with an analog-to-digital converter (ADC) into a digital signal, typically using pulse-code modulation (PCM). This digital signal can then be recorded, edited, modified, and copied using computers ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Synchronization
Synchronization is the coordination of events to operate a system in unison. For example, the conductor of an orchestra keeps the orchestra synchronized or ''in time''. Systems that operate with all parts in synchrony are said to be synchronous or ''in sync''—and those that are not are '' asynchronous''. Today, time synchronization can occur between systems around the world through satellite navigation signals and other time and frequency transfer techniques. Navigation and railways Time-keeping and synchronization of clocks is a critical problem in long-distance ocean navigation. Before radio navigation and satellite-based navigation, navigators required accurate time in conjunction with astronomical observations to determine how far east or west their vessel traveled. The invention of an accurate marine chronometer revolutionized marine navigation. By the end of the 19th century, important ports provided time signals in the form of a signal gun, flag, or dropping ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Optical Fiber
An optical fiber, or optical fibre in Commonwealth English, is a flexible, transparent fiber made by drawing glass ( silica) or plastic to a diameter slightly thicker than that of a human hair. Optical fibers are used most often as a means to transmit light between the two ends of the fiber and find wide usage in fiber-optic communications, where they permit transmission over longer distances and at higher bandwidths (data transfer rates) than electrical cables. Fibers are used instead of metal wires because signals travel along them with less loss; in addition, fibers are immune to electromagnetic interference, a problem from which metal wires suffer. Fibers are also used for illumination and imaging, and are often wrapped in bundles so they may be used to carry light into, or images out of confined spaces, as in the case of a fiberscope. Specially designed fibers are also used for a variety of other applications, some of them being fiber optic sensors and fiber laser ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Unshielded Twisted Pair
Twisted pair cabling is a type of wiring used for communications in which two conductors of a single circuit are twisted together for the purposes of improving electromagnetic compatibility. Compared to a single conductor or an untwisted balanced pair, a twisted pair reduces electromagnetic radiation from the pair and crosstalk between neighboring pairs and improves rejection of external electromagnetic interference. It was invented by Alexander Graham Bell. For additional noise immunity, twisted-pair cabling may be shielded. Cable with shielding is known as shielded twisted pair (STP) and without as unshielded twisted pair (UTP). Explanation A twisted pair can be used as a balanced line, which as part of a balanced circuit can greatly reduce the effect of noise currents induced on the line by coupling of electric or magnetic fields. The idea is that the currents induced in each of the two wires are very nearly equal. The twisting ensures that the two wires are on averag ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
