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

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


Function requirements:
^ On-board power supply
^ Authentication positive
^ Circuit 15R ON

Function
The TV combination tuner (analog/digital) (A90/1) receives and processes both analog and digital television program transmissions and communicates with the COMAND operating, display and control unit (A40/3), the audio gateway control unit (N93/1) and other system components over the installed MOST ring interface. Major controllers in the TV combination tuner (analog/digital) A90/1):
^ 4-fold antenna diversity, separated into video and audio signals
^ Audio antenna diversity
^ Video antenna diversity
^ Multistandard receiver for PAL, Secam and NTSC
^ Multistandard signal processing

TV tuner modules for audio and video
The TV system operates with a total of 3 receiver modules for video and sound signals, whereby 2 tuners are used for video processing in the foreground and a receiver module for background reception (to set up a list of stations). The PLL tuners used cover a reception range of 30 to 866 MHz. The reception range is divided up internally into 3 bands (VHF low, VHF high and UHF). Each band has its own controllable pre-stage. The tuner outputs are of a symmetrical design. The TV combination tuner (analog/digital) (A90/1) has 4 antenna inputs, into which signals are fed from the supplementary car antennas.
The antenna inputs are assigned to the 3 TV receiver units as follows:
^ Ant 1, Ant 2, Ant 3, Ant 4 are assigned to the audio receiver unit
^ Ant 1, Ant 2 are assigned to video reception path 2
^ Ant 3, Ant 4 are assigned to video reception path 1

Each receiver unit can automatically select the most suitable input signal. Audio and picture antenna diversity work separately from each other in order to avoid unpleasant interference noises or picture obliteration during mobile reception. If signal reception is poor (e.g. dead zone) the TV picture is frozen and audio output interrupted.

The TV combination tuner (analog/digital) (A90/1) supports all channel lists and audio standards worldwide.

Digital and analog TV reception, function
The TV combination tuner (analog/digital) (A90/1) enables reception of both analog television stations and terrestrial digital television stations using the antenna structures installed. The Digital Video Broadcasting Terrestrial (DVB-T) standard is supported.
The TV combination tuner (analog/digital) (A90/1) automatically switches between analog and digital TV reception depending on the current reception status. The user has no influence here.

Switchover can only be suppressed with the "CH-Fix" setting. If stations having matching station names are received (e.g. ARD analog and digital), only one entry is made in the list of stations. For security reasons, software updates via the antenna are not possible.

Multistandard signal processing
Signals from the TV combination tuner (analog/digital) (A90/1) modulated onto the IF (intermediate frequency) are demodulated during subsequent signal processing. Both positive and negative amplitude-modulated signals can be processed. The demodulation stage for the sound signal receives a narrow-band filtered intermediate frequency signal which has virtually no video part and cannot cause any further sound interference. The audio signals are AM" or "FM" depending on the TV standard.