Motorola Dimetra MTM300, Руководство по установке

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40 Motorcycle Installation
Figure 42 shows an installation where switching between the front microphone and
loudspeaker and the back fist microphone and external loudspeaker takes place using a
manual double switch S1.
The switch can be activated by hand, or by the hinged cover.
• In “back” position (as shown) the Loudspeaker is on, and the front microphone is
disabled.
• In “front” position, the Loudspeaker is off, and the front or helmet microphone is on.
Figure 42 Example of Manual Select Between “Front” and “Back” use
of Microphone and Loudspeaker
Figure 43 shows an alternative installation of the loudspeaker and headphones where a
serial resistor can be used for volume adjustment. The minimum connected impedance is
3.2 ohm. The audio PA is a bridge amplifier.
Figure 43 Example of Installation with Serial Resistor for Volume Adjustment
Other microphones can be connected either on the Junction Box or on P5.
P4 P5
80 mV
Microphone from Junction Box 1 1
DC imp. 20 Kohm
AC imp. 560 ohm
Bias 7.3 V
Ground 2 2
Microphone impedance 3 3
P3
P1
P2
P5
RADIO
JUNCTION
BOX
FIST MICROPHONE
LOUDSPEAKER
P4
3
1
S1A
CONTROL HEAD
HEADPHONES
EXTERNAL PTT
MICROPHONE
(HANDSFREE)
S1B
JUNCTION BOX
SPEAKER -
LOUDSPEAKER
HEADPHONES
MICROPHONE
S