Technology of Q 2500 colour TV set

Technology of Q 2500 colour TV set3.4 Components3.4.1 Satellite front end3.4.2 Functional distributionThe satellite front-end processes the signal ofthe 1. satellite IF coming from the Universal-LNC or Multiswitch up to the MPEG-2 carriercurrent, fed to the MPEG-2 demultiplexer/decoder.It also houses the componentsfor the supply and control of the antennaunits. The functions mentioned are distributedto blocks of the Sat 6 (Tuner, LNCsupply) unit DVB decoder (AD conversion,demodulation, forward error correction). Theseparation is implemented via an analogue/digitalsatellite tuner in order to be ableto use redundancy free processing of TV andDVB signals. The reasons for the choice ofinterfaces are:Fewer requirements for the screening of theSat 6 unit and low-interference quasianaloguebaseband interface to DVB decoder.Due to the functional unity, the relevant parametersfor DVB reception of the Sat 6 unitare specified in the following.3.4.3 TunerThe tuner converts the signal of the 1. satelliteIF in the base band. Signal processing foranalogue and DVB signals is distinguishedonly in respect of demodulation, and is thereforealmost identical with respect to the prefilteringand amplification stages, mixing onthe 2. IF, channel selection and amplification.For this the implementation of an analogue/digitalcombi-tuner is advised.The Sat 6 unit incorporates theBS2W7VG2002 (Sharp) analogue/digital satellitetunerDocument Q 2500 54 © Loewe ProCollege