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ADR
ASTRA Digital Radio. A transmission system that uses ASTRA to transmit twelve stereo radio
programmes in Hi-Fi quality on a single audio sub-carrier of a TV transponder.
Attenuation
Loss of signal strength, normally expressed in decibels. Attenuation can occur in the connection
cables between the antenna and receiver. It can also be due to the distance between the transmission
antenna and the receiver antenna.
AV
Shorthand for a button, connection plug or an operating mode to activate or connect audio-visual
equipment. The AV connection, e.g. between receiver and TV equipment is normally produced as a
Scart cable and provides better quality than an antenna cable.
Azimuth
From the position of the observer the skywards direction (east/west) of the satellite.
Band
Band defines a range of frequencies between two values set according to technical agreement.
Bandwidth
Expression for a series of frequencies, covered by a particular band.
Bearer
Very high-frequency oscillation that due to modulation can carry a radio, or TV signal over great
distances. The frequency of the oscillation is also the bearer frequency. A TV satellite transmissions,
for each television channel there is an image or visual bearer and one or more audio bearers.
Bowl
Jargon expression for the parabolic reflector.
Broadcasting range
The interval between two frequencies that define a band. In satellite receivers it shows the frequency
range in which you can operate without distortion or error.
CATV
Community Antenna TV. Shorthand for a cable TV signal distribution system
Channel
Part of frequency band allocated according to an agreed allocation procedure. A TV channel consists
of two frequencies, one for the visual and one for the audio content. Every channel is identified by
numerical code (except for the European television channels broadcast on the 40-230 MHz frequency
band, which are identified by a letter code).
Co-ax cable
An item to provide the electrical connection between antenna and receiver. It consists of a special
cable, which has an inner and an outer core. Each is separated by insulating material, to guarantee
minimum signal loss. Co-ax cable is also called shielded cable because the outer core also protects
the inner core from outside interference, thereby minimising the signal loss in the inner core.
Conditional Access System (CA)
To unlock a coded programme, the so-called Conditional Access Module (CAM) is required. The
interfaces for the CA modules are internationally standard. From this came the Common Interface. So
that the digital receiver can accept various CAMs, it has one or more interfaces with the Common
nterface Standard. This CI interface provides the necessary to security for the future for later expansion
of the digital receiver. There are CA modules not only for play-programmes, but also for other
applications such as memory cards or modems
Control signal (22 kHz)
This means a low-frequency signal around 22 kHz with which the satellite receiver provides an
additional switching capability for the LNB / LNBs. If the signal is switched on or off, it is possible to
choose between several antennas via a box connected between the two.
Converter
The receiver unit at the focal point of the parabolic antenna, to convert from the frequency range of
the satellite to the intermediate frequency of the receiver.
dB
Decibel A unit of measurement to express the relationship between values of the same type. It is often
used to express the attenuation of a cable or distance, or the output of an amplifier.
Decoder
Equipment to unlock a coded transmission. Each encoding system has an equivalent decoder. A
decoder can also be used to change one format into another (e.g. D2-MAC to PAL).
Demodulator
The circuit in a satellite receiver, the purpose of which is to filter out the audio and video content from
the bearer signal of a TV channel.
GLOSSARY
“Little SAT lexicon”
Digital
And electronic method to process pictures and sounds. It is based on the conversion of picture and
sound signals into binary values Digital technology is less prone to interference and the signal quality
is higher. Digital audio is already available on CD, DCC, Minidisc, DAT, ADR, etc. Digital video is
available on the MPEG system.
DiSEqC
Digital Satellite Equipment Control – Digital control instructions to reach further stations except for H/V
and 22 kHz.
Dolby Prologic
A system similar to Dolby Surround. The technique of digital delay is used to achieve much greater
dynamic performance of the main channel, or to assign the voice channel to it, whilst directing special
effects to the other four speakers.
Dolby Surround
A system for the processing of audio information in films, television films and video clips. This system
enables the viewer to be acoustically involved in what is going on. The audio environment is artificially
reconstructed, so that the classic stereo channels (front right and front left) have three sound sources
added: the main channel as well as right rear and left rear channels.
Dual Feed
The system for receiving two satellites with a single antenna. The basic requirement for this system is,
that the satellites are not more than 9° apart. The system is mainly used for receiving ASTRA 19.2°
East und EUTELSAT 13° East.
DVB
Digital Video Broadcasting. Digital broadcast standard of TV signals in accordance with the MPEG
standard. These techniques are providing impetus to the various European broadcasters, as far as the
transmission of digital TV signals is concerned.
Elevation
The term elevation refers to the vertical angle at which the antenna must be positioned to be able to
see” the satellite required. Azimuth, therefore, is the horizontal angle. Elevation the vertical angle -
when this is being set the satellite must be “seen”.
EPG
EPG means Electronic Programme Guide and is an electronic programme magazine that is transmitted
with the programmes. The necessary data can easily be obtained from the data stream transmission
of a programme or bouquet satellite. The EPG data supplied by the programme provider must of
course be readable and processable by the DVB receiver. This takes place via the so-called
Application Programming Interface (API).
FM
Frequency modulation. A method of modulation whereby the input signal varies the frequency of the
carrier wave.
Footprint
The area of the earth's surface covered by the beam from a satellite repeater. It refers to the
geographical area in which the particular TV or radio programme can be received. The footprint can
be represented graphically as a series of more or less concentric circles, each of which has a
transmission capacity expressed in dBW. Often, as an alternative the antenna size required within the
circle is shown.
Frequency
A unit of measurement for the number of complete oscillations per second, expressed as oscillations
per second, or Hertz (Hz). Therefore, 950 MHz is equivalent to 950 million oscillations per second.
Gain
A unit of measurement, expressed in decibels, to define the amplification capacity of a parabolic
antenna or amplifier. Gain is the opposite of attenuation. The gain of an antenna depends on the
diameter of the parabolic reflector and its efficiency.
Geo-stationary
Geostationary describes objects above the equator that are moving at the same speed as the rotation
of the earth. From the position of the observer they appear to be stationary
HDTV
High Definition Television, or high-resolution television. This system has been tested by broadcasting
the most important sporting events. The main characteristics of HDTV are: wide-screen format (16:09),
double the number of screen lines (from currently 625 to 1250) and digital audio quality.
Latitude
The separation expressed in degrees of a particular spot on the surface of the earth and the equator.
The corresponding value can be obtained from geographical charts. It is important for the calculation
of the elevation and declination when erecting a fixed or moveable antenna.