Skymaster DVR 9200, Руководство по эксплуатации

Страница: 33 / 40

71
14. SAT lexicon – Explanations of technical terms
39743
Transfer switch:
Transfer switches (sometimes integrated into multi-switches) are required to fan-in SAT and terrestrial
signals. These must be separated again by “reversed” transfer switches or SAT connection boxes.
Reception frequency:
As with VHF reception, each satellite programme has a reception frequency. In contrast to tuning a radio
transmitter, further settings are necessary (polarisation, DiSEqC/22kHz/LO frequency)!
If e.g. the LO frequency no longer agrees with the connected LNB, the transmitter cannot be received!
FEC:
FORWARD ERROR CORRECTION: An error correction system for the transmission path.
High Band:
Frequency range of 11.7-12.75 GHz. Used by satellite systems for broadcasting digital programmes
(see 22 kHz).
Ku Band:
Transmission range of satellites 10.7-12.75 GHz (Low and High Band).
LNB/LNC:
Low Noise Block/Converter. This is located in the focal point of the satellite antenna (exception:
“Multifeed”), and collects and amplifies the signals. As the received signals are too high frequency for
switching via the antenna cable, they must be reduced by means of an “oscillator” (see LO frequency).
The LNB is supplied with voltage by the satellite receiver via the antenna cable and receives the
necessary control commands (horizontal or vertical reception, High or Low Band).
Low Band:
Frequency range of 10.7-11.7 GHz. Used by the Astra satellite system for broadcasting analogue
programmes, amongst other things (see 22 kHz).
LO frequency/oscillator:
LNBs have an oscillator with a fixed LO frequency for Low Band (9.750 GHz), while Universal LNBs have
an additional oscillator for High Band (10.660 GHz). These values are already preset for LNB 1 to LNB 4
and should only be changed if you are using an older LNB type and the LO frequency of your LNB is
known.
Multifeed:
An antenna on which two or more LNBs are mounted, which can receive different satellites.