TechniSat DigitMod S1 Operating Manual page 57

Intermediate frequency:
The range of frequencies broadcast by a satellite cannot be
transmitted via any cable. The LNC therefore converts the
signal received to an intermediate frequency range in the
band 950 to 2150 MHz. This can then be transmitted via
cable, and processed in the digital receiver.
1. IF = Intermediate frequency
LNB/LNC (Low Noise Block Converter):
Reception unit located at the focal point of the parabolic dish,
converts the frequency range of the satellite to the intermedi-
ate frequency of the digital receiver.
LOF:
Local oscillator frequency; stated in MHz or GHz; varies
depending on the LNC and the frequency range received
Reception frequency of the digital receiver = Broadcasr fre-
quency of the satellite - LOF.
Modulation at 22 KHz:
Apart from 14/28 Volt switching, this serves to switch bet-
ween 2 LNC.In Universal LNCs it is used to switch to the
High range.
Operating current:
The LNC is supplied with power via the co-axial cable. To this
end the receiver supplies an operating current of either 14 or
18 Volts.
Parabolic dish:
Surface of metal or coated synthetic material, shaped like a
parabola, receives electromagnetic waves transmitted by a
satellite and concentrates them on a focal point.
Polarisation plane:
To better utilise the available frequency range, satellites bro-
adcast neighbouring programmes with opposite polarisation
(horizontal and vertical or laevorotatory and dextrorotatory).
To receive both polarisation planes you require either two
Single LNCs or a V/H LNC.
Receiver: see satellite receiver
Satellite:
Description of a satellite, usually stating name and orbital
position,
ASTRA
EUTELSAT
Satellite receiver:
signals received from the LNC, and then converted, cannot
be processed by the television set. They are processed in the
satellite receiver so that its outputs carry regular audio and
video (AV) signals, which can then be passed on to the tele-
vision set and processed there.
19° East
13° East
57
(Fig. 10-1)