GF82.71-P-2000T Taxi Hands-Free System Function

GF82.71-P-2000T Taxi Hands-Free System Function
- with CODE (450) Taxi version


Function requirements
^ No overvoltage or undervoltage (is detected by the special vehicle multifunction control unit (SVMCU [MSS]) (N26/9))

The hands-free two-way radio permits the taxi driver to communicate via the two-way radio, e.g. with the taxi control center.
The hands-free two-way radio comprises the following components:
^ Service radio (A49)
^ Microphone (B25/1)
^ Left front double-coil speaker (H4/19)
^ Lower control panel control unit (N72) with two-way radio switch (N72s11)
^ Telephone/GPS/two-way radio roof antenna (A2/49)

The two-way radio (A49) is supplied with power via the special vehicle multifunction control unit (SVMCU [MSS]) (N26/9).
When the two-way radio switch (N72s11) in the lower control panel control unit (N72) is pressed, the two-way radio (A49) is switched to transmission mode. At the same time, the speaker of the radio control panel and navigation unit (A2/56) is muted. Now, the microphone located in the overhead control panel (B25/1) can be used for communication.

The received radio communication is output via the left front double-coil speaker (H4/19). This speaker is also used for normal radio operation.

Electret microphone
This microphone has no coils and is therefore very compact. It is based on the capacitor principle.
A polarized (electret) diaphragm serving as a capacitor plate is caused to move by sound waves. This changes the capacitance with respect to the parallel, rigid second capacitor plate. Connected to both capacitor plates are electrodes. As a result of the changing capacitance, a change in voltage occurs, which can be picked up as a signal and amplified.

When the taxi emergency alarm (Code 934) is activated, the hands-free two-way radio of the special vehicle multifunction control unit (SVMCU [MSS]) (N26/9) is switched to "Monitor".