Northern Airborne Technology AMS42 - Manual (Page 16)

AMS42/44 Dual Channel Audio Controller Manual SM19 Rev. 4.00
Page 1-2 Nov 21, 2003
ENG-FORM: 800-0103.DOT
CONFIDENTIAL AND PROPRIETARY TO NORTHERN AIRBORNE TECHNOLOGY LTD.
During transmit operation, the sidetone of the transceiver in use remains enabled while
all other audio, except DIRECT 2, is muted. This function is specific to each ‘side’ of the
audio controller.
Transceiver interfacing is accomplished through directly switched microphones and
ground referenced keylines. To ensure maximum radio compatibility, no diodes or other
steering components are used.
1.3.2 Receive Functions
Selecting a transceiver with the TX (transmit) rotary selector automatically selects the
associated receive audio. The RX inputs are also selected by the 3-position center-off
front panel switches, five on each side of the audio controller – the ‘up’ position selects
the respective navaid input, and the ‘down’ position selects the repective COM.
Two Direct Audio inputs are provided and are configurable for left or right side use.
1.3.3 ICS Functions
LIVE, KEYED or variable VOX ICS operation can be selected from a single control.
The AMS42 and AMS44 use dynamic noise reduction and voice band filtering to provide
the clearest possible ICS audio in high ambient noise conditions.
Transparent ICS for either the pilot or copilot allows immediate transmit operation with
no control panel switching. Return to ICS operation is automatic upon completion of the
TX operation.
Isolation and Emergency modes of operation are provided to remove the pilot(s) from
the intercom bus without interfering with normal passenger ICS.
Both controllers provide an ICS Tie line for multiple controller installations.
1.4 Specifications
1.4.1 Electrical Specifications
Input Power Typically +22 to +32 Vdc at 250 mA
Nominal +28 Vdc
Lighting
160 mA at 28 Vdc.
600 mA at 5 Vdc.
Microphone Requirement
‘Carbon equivalent’ 250 mV into 150 Ω min.
(David Clark M1/DC, M3, M4, M7 recommended)