GF82.60-P-3109-02QMA TV Tuner, Function

GF82.60-P-3109-02QMA TV Tuner, Function
- with CODE (527) COMAND APS (with navigation)
- with CODE (863) Digital/anlog TV tuner


Receiver modules for audio and video
The TV combination tuner (analog/digital) (A90/1) receives analog and, with a Digital Video Broadcasting-Terrestrial (DVB-T) receiver, also digital TV signals. The TV combination tuner (analog/digital) (A90/1) automatically switches between analog and digital TV reception, depending on the particular reception status. The user cannot influence this. A digital station is only recognizable from a "+" next to the station name. The "DVB-T" standard refers to digital television broadcast over antennas. This enables information to be broadcast on several carrier frequencies in close proximity to each other. If interference occurs with individual carriers on the transmission path, error correction can be carried out in the receiver using a specific method of computation, allowing the viewer to see an undistorted picture. Such interference in reception is unavoidable during reception on the move. The TV system operates with a total of 3 receiver modules for image and sound signal processing.

Of these, 2 receivers are used for reception in the foreground and one receiver for background reception (to build the station list). The receivers used cover a reception range of 30 to 866 MHz. The reception range is divided up internally into the following 3 bands:
^ Very High Fidelity (VHF) low
^ Very High Fidelity (VHF) high
^ Ultra High Fidelity (UHF)

Each band has its own controllable pre-stage. The sound outputs are carried out symmetrically. The TV combination tuner (analog/ digital) (A90/1) has 4 antenna inputs and fed into these are the signals of the car antennas which in ideal conditions complement each other. The car antennas are not assigned to a particular receiver but can be used in the same way by each receiver.

Each receiver can independently select the most suitable input signal. Sound and picture antenna diversity work separately from each other in order to minimize unpleasant interference noises or the picture being erased during reception on the move. The digital audio signals are output in stereo quality.

Multistandard signal processing
The mixed signals from the TV combination tuner (analog/digital) (A90/1) on the intermediate frequency (ZF) level are demodulated in the subsequent signal processing. Both positive and negative amplitude-modulated signals can be processed. The division of the reception path into separate picture and sound processing is already prepared before demodulation by a suitable choice of filters which separate the spectrum into picture and sound shares. The picture signal is demodulated by active carrier recovery in a synchronous demodulator which is particularly low-distortion and has excellent intermodulation characteristics.

The TV combination tuner (analog/digital) (A90/1) is designed for mobile television reception in different countries and is connected via Media Oriented System Transport (MOST) to the COMAND operating, display and control unit (A40/3). The TV combination tuner (analog/digital) (A90/1) is controlled entirely via the COMAND operating, display and control unit (A40/3). The video signals are transmitted by the Composite Video Burst Sync. (CVBS) line to the COMAND operating, display and control unit (A40/3). The TV combination tuner (analog/digital) (A90/1) has neither controls nor a display. The following basic controls of the TV combination tuner (analog/digital) (A90/1) are possible:
^ Multistandard color (PAL, NTSC, Secam), multistandard sound and channel lists
^ Station selection with max. 40 currently receivable stations, which can be assigned to 10 program presets
^ Teletext with page memory
^ Digital picture memory
^ Digital video processing
^ Adaptive Video quality evaluation
^ 4-way antenna diversity, separate audio and video
^ Depiction as picture in picture