Northern Airborne Technology AA83-001 rev.4.00 - Manual (Page 39)

SM09-2A Rev. 4.00 AA83-001 InterMUSIC™ Stereo Intercom System Manual
The copilot and passengers will be unable to monitor any transceiver activity, although
they retain full ICS and music functions.
This mode is 'fail-passive', meaning that it requires no power to operate and is the
same mode the box goes into automatically when power is lost to the AA83-001.
In this way, switch over is immediate for the pilot and there is no possibility of lost
communication because of a lack of pilot action. Note that the pilot's boom mic is sent
directly to the radio in this mode, and only a PTT key input is needed to transmit.
Note: In this mode, the receive/sidetone levels may require adjustment at the audio
source.
3.3.5.3 SPLIT Operation
Operation in SPLIT Mode is similar to NORM mode, but if the AA83-001 is connected
as part of a multi-unit system, the SPLIT mode allows external users to be disconnected
from the AA83-001 ICS communications without requiring adjustment of the ICS Audio
level.
All users are permitted to talk to each other, listen to music, and hear all radio
communications.
There is provision for an external ICS tie line load to maintain the ICS audio at the same
level as in NORM mode.
3.3.6 Radio Functions
There are two PTT inputs: one each for the pilot and copilot. Activation of either PTT
input connects the user’s MIC to the radio, and activates the output PTT to the radio.
Sidetone audio input is provided from the radio, not by the AA83-001 microphone
circuits. Transmit sidetone audio utilizes AA83-001 Radio RX audio and phones driver
circuits.
Radio RX/sidetone is a mono signal, but RX balance control may be adjusted to provide
spatial displacement to aid user in quick signal identification.
Note: A priority transmission feature allows the pilot to override the copilot.
3.3.7 Muting Logic
When transmitting, any music will be muted quickly, and will slowly return when
transmission is completed. Music will also be muted when ICS or RX functions are
active. The degree of muting is set at the time of installation. The relative volume of
the music can be changed from the front panel by the knob marked with a musical
note.
Feb 8, 2006 Page 3-5
ENG-FORM: 806-0106.DOT
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