Damping
Loss of signal strength, usually expressed in term of decibels. Damping can occur in the connecting cables between the antenna and the receiver, as well as in the space between the transmitting antenna and the receiving antenna.

DB
Abbreviation for decibel. Unit of measure expressing the relationships between two comparable dimensions in relation to each other. It is often used to express the damping of a cable or of a distance, or the gain of a receiver.

DBW
Similar to decibel, but related to 1 Watt, dbW is used to express the transmission strength of a satellite transponder.

Decoder
Unit of equipment capable of decoding an encrypted transmission. Every encryption system has its appropriate decoder. A decoder can also be used to transform one format into another, eg D2-MAC into PAL.

De-emphasis, audio
The opposite process of the emphasis, to which an audio signal is subjected. Together, the two serve to improve the signal-to-noise ratio. During transmission, audio frequencies in the upper range are specifically amplified (emphasis). De-emphasis is the process of re-establishing the correct volume relationship between low and high frequencies.

De-emphasis, video
Connection of the demodulated video signal in order to re-establish the correct video frequency strengths in the upper range, which are specifically amplified during transmission (emphasis) in order to reduce video interference.

Digital
Electronic technique for processing pictures and sounds. It is based on the conversion of visual and sound signals to binary numbers. Digital technology is less susceptible to errors and interference. Digital audio is available in several formats - CD, DCC, minidisk, DAT, ADR, etc. Digital video is possible within the MPEG system.

Dish
Colloquial expression for the parabolic reflector/satellite antenna.

Display
Illuminated viewing panel, usually display numbers or letters of the alphabet. It is therefore sometimes known as an alphanumeric display. In satellite receivers it usally shows the channel being received, and other relevant reception parameters. In computer sciences (IT), a standard computer screen is known as a display.

Distributor
Signal distributor that is required to distribute the signal received by one piece of equipment (LNB or receiver) to a number of receivers.

D-MAC
Transmission technology utilising multiplex technology (ie multiple switching) in order to transmit the components of a TV signal - sound, brightness and colour. This system is characterized by the facility of providing up to eight audio channels.

D2-MAC
This system was developed on the basis of D-MAC. It features minor differences in signal processing, has a smaller video bandwidth and can provide only four audio channels.

DNR
Abbreviation for Dynamic Noise Reduction System used to reduce noise in the audio range. DNR emphasises the highest frequencies during recording, eg onto magnetic tape and re-creates the original strength during reproduction.

Dolby Prologic
System similar to the Dolby Surround System. Digital delay technology is used to achieve a greater dynamic performance of the central channel, or it can be added to the voice channel while special effects are distributed to the other four loudspeakers.

Dolby Surround
System for processing audio information in cinema and TV movies as well as in video clips. The system is used to the draw the viewer acoustically into the story. The sound ambience is reconstructed artificially, by adding three sound points to the classical stereo channels (front left and front right) - a central channel, as well as rear left and rear right channels.

Downlink
Microwave connection between the satellite and the receiving station on the ground.

DVB
Abbreviation for Digital Video Broadcasting. A digital distribution standard for TV signals based on the MPEG standard.