Northern Airborne Technology AMS43 TSO - Manual (Page 26)

AMS43 TSO Single Channel Audio Controller
SM27 Installation and Operation Manual
3.3.3 ICS Functions
Mode switch VOX Squelch
Control
ICS Mode switch
ICS Volume
Control
3.3.3.1 ICS Modes
Intercom audio may be implemented in three modes: LIVE (on constantly), VOX (voice activated), or
KEYED (active only when switched by ICS PTT switch). It is common to use the LIVE mode during
ground operations, start-up, etc. and to use VOX or KEYED operation if conditions are so noisy that ‘pilot
fatigue’ will result.
LIVE (Hot Mic Operation)
ICS mode switch (orange switch bat) set to the up (VOX) position and the VOX squelch control set to the
full counter-clockwise position.
KEYED ICS (PTT Operation)
ICS toggle switch (orange switch bat) set to the down (KEY) position. Keyed ICS is inherent to the pilot
and copilot microphone circuits only.
VOX (Voice Activated)
ICS toggle switch (orange switch bat) set to the up (VOX) position. Set the ICS VOX Squelch control fully
counter-clockwise and then slowly rotate clockwise until the intercom just becomes quiet. This setting will
vary with ambient noise conditions, and the quality and number of microphones connected in the system.
3.3.3.2 General ICS Functions
Passenger ICS audio is LIVE when the controller is in the LIVE or KEYED mode of ICS operation. It is
VOX triggered when that mode is selected. The passengers are always LIVE unless interrupted by an in-
line PTT cord, or if the controller is set for VOX operation. Passenger and observer (copilot) operations
can be optimized by using in-line PTT type cord assemblies designed for use with NAT audio controllers.
All ICS audio is controlled by the front panel ICS volume control and may be varied to suit conditions.
The ICS VOL control provides adjustment from approximately 1% to full output.
The mode switch (red switch bat) is used to select between NORMAL and PILOT ISO/EMR modes. In the
NORMAL position (down), all operations of the ICS are functional as described above. When the switch is in
the pilot isolate/emergency position (PILOT ISO/EMR), the pilot is isolated from the rest of the passengers. If
the controller is operated in the ISO/EMR mode, ICS operation will continue (if there is no fault condition)
between the passengers and copilot, but will exclude the pilot. See section 3.4 for further details.
Section 3 Rev: 1.00 Issue 4 Page 3-3
ENG-FORM: 806-0115.DOT
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