Northern Airborne Technology AMS50 - Manual (Page 51)

SM50 Rev. 4.00 AMS50-000 Stereo Audio Panel with Marker Manual
3.2.5
ICS and VOX Volume Control
VOX/TX Indicator LED
VOX Control
(Outer knob)
ICS Volume Control
(Inner Knob)
The ICS and VOX volume controls for the Crew and Passenger groups consists of a
concentric control knob – the inner knob controls the ICS volume, and the outer knob
controls the sensitivity of the VOX circuit. Turning the ICS volume knob completely
counter-clockwise (ccw) to the detent will switch the unit to manual fail-safe mode. (See
section 3.2.5.3.)
3.2.5.1
VOX Control
The VOX control is used to adjust the voice level that is required to activate the mic and
pass the audio to the headsets. Rotating the control clockwise (cw) decreases the
sensitivity of the circuit, and ccw increases it until in the fully ccw position, all the mics
are live. The VOX squelch can be set as described in section 3.2.5.2.
3.2.5.2
VOX/TX Indicator LED
The VOX/TX indicator is a bicolor LED located in the upper right corner of the panel.
The LED will illuminate amber to indicate any transmit activity, and will illuminate green
to indicate that one of the six VOX squelch circuits has been triggered. The TX LED
(amber) always overrides the VOX LED (green).
TX Indication
The LED will illuminate amber to indicate any transmit activity (when a radio PTT has
been triggered), and will also indicate a stuck Mic (PTT) if it remains lit after
transmission is concluded. The amber LED is only on during Pilot or Co-pilot TX Key in
ALL and CREW mode, and only on for the Pilot TX Key in PLT ISO mode. The TX LED
does not illuminate at any time when COM3 is selected in a ‘telephone’ installation.
VOX Indication
The LED will illuminate green to indicate that one of the six VOX squelch circuits has
been triggered. It can be used to set the VOX threshold by turning the VOX control
knob ccw until the LED turns green, and then rotating the control cw until the LED goes
dark. Continue turning the knob cw until the desired voice sensitivity is reached.
Nov 12, 2003 Page 3-5
ENG-FORM: 806-0104.DOT
CONFIDENTIAL AND PROPRIETARY TO NORTHERN AIRBORNE TECHNOLOGY LTD.