GF82.60-P-2001QM Radio Mode, Function

GF82.60-P-2001QM Radio Mode, Function
- with CODE (527) COMAND APS (with navigation)

After the COMAND operating, display and control unit (A40/3) has been activated by pressing the "FM/AM" button, in Model 209.3 the antennas in the rear window receive high-frequency signals for very-high frequency (VHF (FM)), short wave (SW), medium wave (MW) and long wave (LW). In Model 209.4, the antenna in the windshield receives the FM high frequency signals and the A trunk lid antenna (A71/1) receives the SW, MW and LW high-frequency signals. The music, voice and data signals are modulated upon these high-frequency signals. The window antenna amplifier module 2 (A2/72) in Model 209.3 filters the frequencies of the radio frequency bands out of the high-frequency signals received and amplifies them. The left antenna amplifier module (A2/64) and the AM trunk lid antenna amplifier (A2/16) for Model 209.4 filter 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 cable to the radio receiver in the COMAND operating, display and control unit (A40/3). The radio receiver separates the useful information (audible frequencies) from the carrier signal (inaudible). The demodulated audio signals are amplified and converted to sound signals by the vehicle speakers.

FM antenna diversity, function
With the "antenna diversity" function, the system switches, depending on reception, between the FM antennas of the rear window (Model 209.3) or the FM antennas of the windshield (Model 209.4). The function runs automatically and is implemented by the window antenna amplifier module 2 (A2/72) (Model 209.3) or the left antenna amplifier module (A2/64) (Model 209.4).

The radio tuner of the COMAND operating, display and control unit (A40/3) only generates the intermediate frequency (IF) signal, which serves the window antenna amplifier module 2 (A2/72 (Model 209.3) and the left antenna amplifier model (A2/64) (model 209.4) as a reference for changing the FM antenna.

2-receiver technology function
After the COMAND operating, display and control unit (A40/3) has been switched on, a 2nd (integral) radio receiver automatically generates a list of the FM-stations received, this list being continuously updated during operation. This list appears, sorted alphabetically, when the "FM station list" menu is called up.

The station list is only available when the "RDS" function is activated. If reception interference occurs 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 2nd receiver and then tries to switch over accordingly if reception is improved.

Certain radio channel programs are subdivided into regional programs at certain transmission times. As the COMAND operating, display and control unit (A40/3) automatically switches to an alternative station frequency in case of reception interference, this may also lead to a change in regional program.

Radio Data System (RDS) function
Apart from the normal radio program, many radio stations (FM) transmit additional 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 indicated on the display if:
^ An RDS station is adjusted
^ The RDS function is activated

The radio component of the COMAND operating, display and control unit (A40/3) also provides:
^ a station list of the currently most powerful FM stations in RDS mode
^ an automatic memory for the most powerful MW/LW stations
^ a program type selection (PTY, e.g. culture, entertainment, pop) for FM-stations in RDS-mode

Station selection options are:
^ automatic station search with "scan" function (the stations of one waveband are played for 8 s)
^ station search at the multifunction steering wheel (MFL)
^ Manual station search
^ Station selection with station list
^ Station selection with number buttons
^ Station selection by entering the frequency (e.g. 92.2 MHz)
^ station selection from the memory (10 stations per waveband)