GF82.62-P-3105-04T Antenna Amplifier Module, Function

GF82.62-P-3105-04T Antenna Amplifier Module, Function
- except CODE (494) USA version
- except CODE (498) Japan version


Filtering and amplifying radio frequency signals
The electric filters of the left antenna amplifier module (A2/64) and the right antenna amplifier module (A2/65) select the required frequency bands (AM, FM, TV) from the high frequency signals received by the antennas in the rear window. Depending on the country (e.g. United States Of America, Japan), these filters are designed differently, as the transmission frequencies depend on the country. The filtered frequency bands are than amplified selectively and relayed via coaxial cables to the corresponding control units, e.g.:
^ Audio gateway control unit (N93/1)
^ TV tuner (A2/10)
^ EIS [EZS] control unit (N73)

Demodulation of radio remote central locking signals
The signals for radio remote central locking (RRCL) are demodulated by the left antenna amplifier module (A2/64) and digitized. The information prepared in this way is transmitted to the electronic ignition switch control unit (N73) via a separate data line, where it is put onto the interior CAN (CAN-B).

During demodulation the useful signal (e.g. the radio remote central locking signal) is separated from the high frequency carrier frequency (transmit frequency).

Equipment
The functionality of the left antenna amplifier module (A2/64) is suitable for the three equipment variants as far as radio operation is concerned:
^ Audio 20 CC (radio (A2)) with AM/FM amplifier and radio remote central locking receiver
^ with code (525) MB Audio 50 APS radio with AM/FM amplifier with antenna diversity and radio remote central locking receiver
^ with code (527) navigation module for COMAND with AM/FM amplifier with antenna diversity and radio remote central locking receiver and 2 TV amplifiers

For TV mode, the right antenna amplifier module (A2/65) with additional TV amplifiers is also needed. With code (889) Keyless Go, this module also contains the necessary receiver.

The left antenna amplifier module (A2/64) is the receiver for AM/ FM and RRCL (radio remote central locking). In vehicles with FM diversity the AM amplifier and the diversity unit and the radio remote central locking receiver are built into the same housing. The assembly is completed by a separate 2-way FM amplifier, amplifier module 1, window antenna (A2/71). TV reception is realized by the right antenna amplifier module (A2/65) in combination with amplifier module 2, window antenna (A2/72) in model 211.2.
To rule out overlap of the radio and TV frequency ranges, the antenna amplifier modules belonging to the corresponding system are installed diagonally.