GF82.60-P-3109-02RA TV Tuner, Function
GF82.60-P-3109-02RA TV Tuner, Function
- with CODE (352) COMAND operating and display system
- except CODE (491) USA version
- except CODE (498) Japan version
TV tuner modules for audio and video
3 The TV system works with a total of three reception modules whereby 3 tuners are used for picture processing and 2 tuners are used for the sound signal.2 The PLL tuners used cover a reception range of 45 to 866 MHz. The reception range is divided up internally into three bands: VHF low, VHF high and UHF. Each band has its own controllable preliminary stage. The sound outputs are carried out symmetrically.
The TV tuner box has 4 antenna inputs into which ideally the complementary vehicle antenna are fed.
The antennae are not assigned to a particular tuner but can be used in the same way by each tuner.
Each receiver unit can select the most suitable input signal.
Audio/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.
Multistandard signal processing
The mixed signals from the TV tuner (A2/42) at the IF level are demodulated in the following 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 taken into account before demodulation by suitable choice of the 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 oscillator circuit, the frequency of which is switchable, of the synchronous modulator also enables signal processing of TV signals in the spectral inverse such as is usual to some extent in France (FM). So that all TV standard signals can be received and can be converted into a standardized basic band FBAS format.
This FBAS signal is a defined input signal for the following function units of the TV tuner box.
The demodulation stage for the sound signal receives a narrow- band filtered ZF signal, which is practically without video shares and can no longer cause interference with the sound. The sound signals are AM or FM modulated depending on the TV standard. AM sound and FM sound are converted to a lower second intermediate frequency. Adjustment-free PLL demodulators take over the following demodulation.
The TV tuner (A2/42) is designed for mobile television reception in various countries. It is connected directly to COMAND. The tuner is completely controlled by COMAND. The picture signals are transmitted via RGB outputs. The TV tuner does not have either its own controls or displays.
Essential controls of the TV tuner (A2/42):
^ Multistandard color (PAL, NTSC, Secam) 50/60Hz sound and channel lists
^ Search aid with a maximum of 40 stations which can currently be received. These can be assigned individually and alphabetically with 10 program memory locations
^ Playing part of a track, function
^ Video text with side memory (sides: 100 - 899)
^ Top text optional
^ Digital picture memory
^ Digital video processing
^ Adaptive Video quality evaluation
^ 4-fold antenna diversity, audio and video are separate
^ Audio antenna diversity
^ Video antenna diversity
^ Frequency diversity (when the VPS signal is present)
^ Finding an alternative frequency via VPS information,
^ Picture diversity