Radio mode, function

P82.60-4770-09

Block diagram for radio A2
Overall system, shown with MB Audio 20 radio (Code 523) with CD disk drive, CD changer, (Code 819) and "Portable CTEL" UPCI telephone system (Code 388)

1 Vehicle loudspeakers

2 Rear window antennas

A1 Instrument cluster

A2 Radio

A2/6 CD changer

A2/49 a1 Telephone antenna

Abbreviations

AM AM frequency bands

FM FM frequency bands

CAN-B Control Area Network bus class B (interior)

CAN-C Controller Area Network bus Class C (engine compartment)

MFL Multifunction steering wheel

MOST Media Oriented System Transport

A2/64 Left antenna amplifier module

A28/3 E-net compensator

A34/6 Portable CTEL

A34/15 Universal Portable CTEL Interface (UPCI) portable CTEL holder

A67b/1 Hands-free system microphone group

N80 Steering column module

N93 Central gateway control unit

N123/1 Universal Portable CTEL Interface (UPCI [UHI]) control unit

Radio reception, function

The AM and FM signals received by the antennas integrated into the rear window are forwarded to the left antenna amplifier module (A2/64). The AM and FM signals are filtered, amplified and sent to the radio (A2).

-----------------------------------------------------------------------------------------

The AM and FM signals are demodulated in the radio receiver unit for FM, MW, LW and SW, the useful signal is amplified and converted into sound waves that are emitted at the vehicle speakers.

-----------------------------------------------------------------------------------------

By pressing the FM/AM function key the system switches to the radio menu. The station tuning options are:

 List of stations (as per/previous memory place

 Program type list

 Frequency list

 Station search (as per/previous station)

 Station search at multifunction steering wheel

 Autostore memory

 Scan search (each station of a waveband is played for
8 seconds)

 Manual tuning

 Station memory, 10 preset stations can be stored per waveband, FM, MW, LW, SW

 Manual frequency input (using 12-button control panel)

The following functions that are also available appear on radio display:

 AM noise suppression

 Selection of RDS stations with a strong signal

 RDS functions

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 names, program type (e.g. pop, culture, etc.) and traffic radio recognition.

This information is evaluated by the radio and shown on the display if the following prerequisites are met:

 An RDS station is tuned

 The RDS function is activated