Radio mode, function - GF82.60-P-2001TA

MODEL 211.0 /2 up to 31.5.06 with CODE (527) COMAND APS (with navigation)

Fig 1: Networking Of Radio Mode Components

Courtesy of MERCEDES-BENZ OF NORTH AMERICA.

COMAND operating, display and control unit (A40/3) in radio mode with code (813) Voice control system (VCS), shown on MODEL 211.0

Radio reception, function

The antennas in the rear window receive FM and AM (LW, SW) radio frequency signals. The music, voice and/or data signal is modulated upon 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 from the left antenna amplifier module (A2/64) via a joint coaxial line (FM, AM) to the radio receiver in the audio gateway control unit (N93/1).

The radio receiver demodulates the high frequency 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 key on the COMAND operating, display and control unit (A40/3) leads to the radio menu where the following subfunctions can be set.

These are shown in the display:

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 radio recognition.

This information is evaluated by the COMAND operating, display and control unit (A40/3) and displayed on the screen, if an RDS station is tuned and the RDS function is activated.

FM antenna diversity

If reception problems occur while driving, the COMAND operating, display and control unit (A40/3) 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 programs are subdivided into regional programs. As the COMAND operating, display and control unit (A40/3), as described above, automatically switches to an alternative station frequency because of reception interference, this may also lead to a change in 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 proceeds automatically and is carried out by the left antenna amplifier module (A2/64). The radio tuner merely generates the ZF signal (intermediate frequency), which is used by the antenna amplifier as a reference for changing the FM antenna.

RDS diversity/two-receiver technology, function

The system consists of two FM receivers, an audio receiver and a search receiver. After turning on the radio at the radio control panel, 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.

Audio gateway control unit Location/task/design/function		GF82.62-P-3102T
Antenna amplifier module, location/task/design/function	except CODE (494), USA version except CODE (498) Japanese version	GF82.62-P-3105T
Rear window antenna, location/task/design/function	Model 211.0 except CODE (494), USA version except CODE (498) Japanese version	GF82.62-P-3106T
Rear window antenna, location/task/design/function	Model 211.2 except CODE (494), USA version except CODE (498) Japanese version	GF82.62-P-3106TS