Helicopter (U174) Connection Diagram; Details On Making The Connections - Bose A20 Notice D'utilisation

Helicopter (U174) connection diagram

Existing wiring to
helicopter intercom/
audio panel
Note: Barrel ground (gnd) refers to aircraft grounds.

Details on making the connections

The pinouts for the optional installed connector are detailed in the table below:
Pin number Color
1 Red
2 Black
3 White
4 Blue
Note: For stereo operation, connect the left and right channels to their respective
positions. For monaural operation, connect pins 3 and 4 together, and to the tip of
the existing phone jack.
5 White
6 White/Blue
Note: If the microphone works on radio transmit but not through the intercom, check pin 6.
It may be incorrectly wired to the PTT segment of the microphone jack.
Comm Shield Black
Mic Shield Black
Note: The wires connecting pins 3 and 4 and pins 5 and 6 are shielded, twisted pairs with
a black wire shield termination exiting each pair. If the existing wiring is not shielded,
connect the shields to the existing audio wiring shields, or connect the shield from
Comm L and Comm R wire pair to audio ground.
WHT/BLU
6 MIC LO
WHT
5 MIC HI
BLU
4 COMM R
WHT
3 COMM L
BLK
2 GND
RED
10-32
1 V+IN
1/2A
V DC
Existing single 4-
prong jack
Barrel
(audio gnd)
Purpose
V+IN: Headset power (10-32 VDC). Use a 1/4 amp fuse or
a 1/2 amp circuit breaker.
GND: System ground. Connect to the existing audio
ground.
COMM L: Phone communication: Left.
COMM R: Phone communication: Right.
MIC HI: Microphone/Hi-audio. Connect to the portion of
the existing microphone jack that corresponds to the ring
position of a headset microphone plug. Do not connect to
the tip (PTT) segment.
MIC LO: Microphone/Lo-ground. Connect to the portion
of the microphone jack that corresponds to the barrel
position of a headset microphone plug.
Shield from Comm L and Comm R wire pair.
Shield from Mic Hi and Mic Lo wire pair.
Technical Information
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