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Tuner
| Telecommunications Glossary |
A device, circuit, or portion of a circuit that is used to select one signal from a number of signals in a given frequency range.
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Tvro - television receive only, английский
Earth stations which receive (but not transmit) satellite transmissions. normally comprised of a parabolic antenna, low noise converted (lnc) or low noise amplifier (lna) and a satellite receiver. the antenna gathers the weak signals transmitted from the communications satellite located in the geostationary orbit which are then amplified and downconverted to a more usable portion of the spectrum by the low noise converted. from the lnc the signals may travel up to several hundred feet to a satellite receiver; the output of which is typically video and audio or modulated channel three or four. 23b+d the capability of isdn primary rate interface (pri) to enable data terminals served by a dms-100 isdn node to have fully digital circuit- and packet-switched isdn internetworking with data terminals served by pbxs.
Transponder - channel - downlink frequency, английский
A satellite microwave repeater (receiver and transmitter) receives the signal from an uplink, amplifies it, down converts the frequency of a received band of signals, and re-transmits the signal back to earth. satellites have 12, 24, or more transponders each with the capacity for one color tv signal and two audio channels. typically transponder with 24 transponders have twelve polarized for vertical and twelve for horizontal transmissions in order to optimize the bandwidth of the satellite and the respective transponders.
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