GF82.85-P-2030TM Audio Mode, Function
GF82.85-P-2030TM Audio Mode, Function
- with CODE (527) COMAND APS with single DVD drive (with navigation)
- Radio, CD
Radio reception, function
The antennas in the rear window receive high frequency (HF) signals for FM and AM (LW, KW). The music, voice or data signals are modulated onto these high frequency signals. The left antenna amplifier module (A2/64) filters the radio frequency band frequencies from the received high frequency signals and amplifies them.
The amplified signals are then transmitted from the left antenna amplifier module via a joint coaxial line (FM, AM) to the radio receiver in the audio gateway control unit (N93/1).
The radio receiver demodulates the HF signals, in other words it separates the useful information (audible frequencies) from the carrier signal (inaudible). The demodulated audio signals are amplified and converted into sound signals by the vehicle speakers.
Radio mode
Pressing the AUDIO function key on the COMAND operating, display and controller unit (A40/3) leads the user to the radio menu and the following subfunctions shown on the display can be adjusted:
^ AM noise suppression
^ Selection of RDS stations with good reception
^ RDS functions PS, TP, TA, EON, PTY, PTY 30/31
^ FM antenna diversity, function
^ TMC (only in combination with navigation)
^ Station selection
Station selection
Different ways of tuning in stations:
^ Tuning by list of stations
^ Tuning by program type list
^ Tuning by frequency list
^ Tuning by station search
^ Tuning by station search on multifunction steering wheel
^ Tuning by autostore memory
^ Tuning by scan-search (the stations of a waveband are played for 8 seconds)
^ Manual tuning
^ Tuning by station memory (10 stations preset for each waveband and 7 stations in the weather band)
^ Tuning by manual frequency entry (using 12-button control panel on operating unit)
Radio Data System (RDS), function (regional mode)
Apart from the normal radio program, many radio stations (FM) transmit additional inaudible digital information such as station name, program type (PTY) (e.g. pop, culture, etc.) and traffic program identification.
This information is evaluated by the COMAND operating, display and controller unit and displayed on the screen, if an RDS station is tuned in and the RDS function is activated.
FM antenna diversity
If reception problems occur while driving, the COMAND operating, display and controller unit tries to receive the selected station on an alternative frequency with the aid of the second receiver and then tries to switch over accordingly if reception improves.
At certain times, some radio channel programs are subdivided into regional programs. Since the COMAND operating, display and controller unit, as described above, automatically changes to an alternative station frequency in the event of reception faults, this can likewise lead to a change of the regional program. If this is not desired, the "Regional program" entry can be activated under the "FM settings" menu.
FM antenna diversity, function
The antenna diversity function switches between the FM antennas in the rear window depending on the reception. The function runs automatically and is carried out by the left antenna amplifier module. The radio tuner merely generates the intermediate frequency (IF [ZF]) signal which the antenna amplifier uses as a reference for changing the FM antenna.
RDS diversity/2-receiver technology, function
The system consists of 2 FM receivers, an audio receiver and a search receiver. After activation of the radio system, the search receiver automatically generates a list of FM stations received, which is continually updated during operation. Data such as reception quality, programs and alternative frequencies are stored. The audio receiver can therefore switch over inaudibly to an alternative frequency. The list appears in alphabetical order when the "FM station list" is called up. The displayed stations can be activated through selection and confirmation.
The station list is only available when the RDS function is activated.
