With code (523) MB Audio 20 radio - GF82.85-P-2030GQD

MODEL 164.8 with CODE (523) MB Audio 20 radio as of model year 09/YoM 08 

Function requirements 

- Status "Circuit 30 ON" or "Circuit 15R ON"

- The radio is authorized and in perfect working order

- No fault in antenna system (radio function)

- Audio-CD is inserted (for disk operation)

- A radio data system (RDS) station is set and the RDS function is activated

- Radio stations also transmit additional digital information

- Traffic Announcement (TA) function set on the radio (A2)

General audio mode function sequence 

The audio mode function consists of the following function sequences:

- Radio operation (FM/AM/SW/LW/MW) function sequence 

- Disk function sequence 

Operating instructions 

Control, selection or adjustment of the audio functions is possible with the following components:

- Left multifunction steering wheel button group (S110) or right multifunction steering wheel button group (S111)

- Control buttons on the radio

Radio operation (FM/AM/SW/LW/MW) function sequence 

The rear window antennas or the FM/AM/RRCL [FZV] antenna (A2/93a1) in the roof antenna module (A2/93) receive high frequency (HF) signals for the FM and AM (MW, LW, SW) radio frequency bands. The following useful signals relevant for the radio reception are modulated onto these HF signals:

- Music signals

- Speech signals

- Data signals (e.g. Traffic Message Channel (TMC) messages (traffic information))

The HF signals from the rear window antennas are forwarded via direct lines to the FM rear window antenna amplifier (A2/19) and from there to the roof antenna module. These two amplifiers filter the frequencies of the radio frequency bands out of the received HF signals and amplify them. The amplified signals are then sent from the roof antenna module via coaxial lines (FM, AM) to the tuner integrated in the radio where they are demodulated and undergo final amplification.

The demodulated audio signals are output directly on the following speakers by the radio:

- Left front door speaker (H4/5)

- Right front door speaker (H4/6)

- Left rear door speaker (H4/3)

- Right rear door speaker (H4/4)

- Left front door tweeter (H4/33)

- Right front door tweeter (H4/34)

- Left rear door tweeter (H4/35)

- Right rear door tweeter (H4/36)

The function sequence for the radio mode also consists of the following subfunctions:

- Function sequence for AM tuner (MW, LW, SW)

- FM double tuner function sequence with phase diversity

- TP traffic information function sequence (FM only)

- RDS function sequence (with FM only)