Intermediate Frequency if, Modulator, Mode

bed_anl_DIGITY 1_englisch_4.qxd 21.06.02 13:41 Seite 32

Intermediate Frequency (IF):

The frequency range broadcast by a satellite cannot be transmitted via a cable connection. The LNB thus converts the signal to an interim frequency range of 950 to 2050 MHz, which enables the signal to be received and processed by the receiver.

1. IF = Interim Frequency,

LNB/LNC (Low Noise Block converter):

The receiving unit at the focal point of the parabolic dish antenna, it converts signals from the frequency range of the satellite into the intermediate frequency of the receiver

LOF:

Local oscillator frequency, stated in terms of MHz or GHz, varies according to LNB as well as according to the frequency range received.

Reception frequency of the receiver = Broadcast frequency of the satellite - LOF

Modulation at 22 KHz

This, in addition to 14/18 Volt switching, serves to switch between two LNBs. In Universal LNBs it serves to switch to high band

Modulator

Switching mechanism in a satellite receiver or video recorder, serves to facilitate connection via antenna cable

Mode:

determines whether a mono or stereo programme is received

Multyfeed:

External unit, consisting of one parabolic dish and several LNBs, used to receive signals from several satellites

Parabolic dish antenna:

Dish formed in parabolic shape, made of metal or coated synthetic material, focuses the electromagnetic waves received from a satellite in a focal point (where the LNB is mounted)

Polarisation plane:

In order to better utilize the frequency range, satellites broadcast neighbouring programmes with opposite polarization (horizontal and vertical, or dextro-rotatory and laevo-rotatory). In order to receive both polarisation planes one needs either two single LNBs or one V/H-LNB.

Receiver: see Satellite receiver

Satellite:

Description of satellite, usually a name in conjunction with the orbital position,

ASTRA	19° East
EUTELSAT	13° East

Satellite receiver:

The signals received and converted by the LNB cannot be processed by the TV set. The satellite receiver modulates and processes them in such a way that audio and video signals (AV) are created at its outputs, which are fed on to the TV set.

SCART:

Connector plug/socket found on TV sets, video recorders, satellite receivers and other home electronic equipment, used to transmit audio (sound) and video (picture) signals (AV).