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

MODEL 211.0 /2 up to 30.6.06 with CODE (528) HIGH Class USA

Fig 1: Networking Of Radio Mode Components

Courtesy of MERCEDES-BENZ OF NORTH AMERICA.

Radio reception, function

The antennas in the rear window receive high frequency signals for ultra-short wave (FM) and medium wave (MW) as well as weather information. Modulated onto these high frequency signals are the music, language or data 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

The radio menu is reached by pressing the AUDIO function key on the COMAND operating, display and control unit (A40/3). Following this, the radio mode controls can be used to set the following subfunctions, which are then shown on the display of the COMAND operating, display and control unit (A40/3):

AM noise suppression
Selection of Radio Broadcast Data System (RBDS) stations with good reception
RBDS functions (PS, TP, TA, EON, PTY, PTY 30/31)
FM antenna diversity, function
Station selection

Station selection

Different ways of tuning in stations:

Tuning by list of stations
Tuning by program type list
Tuning via 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 input (via the 12-button control panel of the operating unit)

Radio Broadcast Data System (RBDS) function (Regional mode)

In addition to the radio program, many radio stations (FM) also transmit additional inaudible digital information.

These include, for example station names, program type (PTY) (e.g. pop, culture) and traffic program identification. This information is evaluated by the COMAND operating, display and control unit (A40/3) and shown on the display, if an RBDS station is tuned and the RBDS function is activated.

FM antenna diversity, function

If reception faults 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 radio tuner and to switch over accordingly if reception improves. Similarly a switchover is made depending on reception quality between the rear window FM antennas. The function proceeds automatically and is carried out by the left antenna amplifier module (A2/64).

The radio tuner only generates the intermediate frequency (IF) signal, which serves the left antenna amplifier module (A2/64) as a reference for switching over the FM antennas.

At certain times, some radio station 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.

Satellite radio system (SIRIUS)

The system "Satellite radio" is a universal radio system, which serves to ensure sufficient coverage by means of 3 satellites and approx. 100 converters. The following additional components are required for reception in the vehicle:

SDAR antenna (A2/82) (irrespective of FM and MW reception)
SDAR control unit (N87/5)

Satellite radio, location/task		GF82.85-P-3113TU
Satellite radio, location/task	With code (536) SIRIUS satellite radio	GF82.85-P-3113TUA
Audio gateway control unit, location/task/design/function		GF82.62-P-3102TU
Antenna amplifier module, location/task/design/function		GF82.62-P-3105TU
Rear window antenna, location/task/design/function	Model 211.0	GF82.62-P-3106TU
Rear window antenna, location/task/design/function	Model 211.2	GF82.62-P-3106TSU
Radio satellite antenna, location/task		GF82.62-P-4109TU
	Model 211.0 with code (536) SIRIUS satellite radio	GF82.62-P-4109TUA
	Model 211.2 with code (536) SIRIUS satellite radio	GF82.62-P-4109TUB