Radio mode, function

After activating the "radio mode" function by operating the "FM/AM" button of the COMAND operating, display and control unit (A40/3) in the "Audio" menu, the AM antenna in the rear window with the rear window antenna amplifier module (A2/12) or the rear shelf antenna (A2/68) with the rear shelf antenna amplifier (A2/67) receives, depending on the position of the roof (open, closed), high frequency signals for short wave (SW), medium wave (MW), and long wave (LW). The FM antennas in the windshield receive high frequency signals for ultra-short wave (FM) and forward them to the left antenna amplifier module (A2/64). The music, voice, and data signals are modulated onto these high frequency signals. The left antenna amplifier module (A2/64) filters the frequencies of the radio frequency bands out of the high-frequency signals received and amplifies them. The amplified signals are then transmitted via a coaxial line to the radio tuner in the audio gateway control unit (N93/1).

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The radio tuner separates the useful information (audible frequencies) from the carrier signal (not audible). The demodulated audio signals are amplified and converted to sound signals by the vehicle speakers.

Antenna diversity, function

The "antenna diversity" function switches between the FM antennas of the windshield depending on the reception. The function proceeds automatically and is carried out by the left antenna amplifier module (A2/64). The radio tuner in the audio gateway control unit (N93/1) only creates the intermediate frequency (IF) signal. The IF signal is used as a reference for the left antenna amplifier module (A2/64) for changing the FM antenna.

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2-receiver technology function

A 2nd (integral) radio receiver in the audio gateway control unit (N93/1) automatically creates a list of the FM stations received after switching on the COMAND operating, display and control unit (A40/3); the list is updated continuously during operation. This list appears, sorted alphabetically, when the "FM station list" menu is called up. The stations which are displayed can be activated by selecting and confirming.

 The station list is available only when the "radio data system (RDS)" function is activated. If reception faults occur while driving, with the aid of the 2nd receiver the COMAND operating, display and control unit (A40/3) tries to receive the selected station on an alternative frequency and to switch over accordingly if reception improves.

At certain times, some radio channel programs are subdivided into regional programs.

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As the COMAND operating, display and control unit (A40/3) automatically changes to an alternative station frequency in the event of reception faults, this can likewise lead to a change of regional program.

RDS function

Apart from the normal radio program, many radio stations (FM) transmit additional digital information such as station names, program type (e.g. pop, culture, etc.) and traffic radio recognition. This information is evaluated by the COMAND operating, display and control unit (A40/3) and displayed on the screen, if the following prerequisites apply:

 An RDS station is tuned

 The "RDS" function is activated

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The radio tuner in the audio gateway control unit (N93/1) offers the following additional functions:

 A station list of the currently most powerful FM stations in RDS mode

 An automatic memory for the strongest AM stations

 A selection of program type (e.g. pop, culture, etc.) for FM stations in RDS mode

Station selection options:

 automatic station search with scan function (the stations of one waveband are played for 8 s)

 Station search at multifunction steering wheel (MFL)

 Manual station search

 Station selection with station list

 Station selection with number buttons

 Station selection by entering frequency (e.g. 92.2 MHz)

 station selection from the memory (10 stations per waveband)