Northern Airborne Technology AA9x - Manual (Page 46)

AA9x Series Single Channel Audio Controller
SM56 Installation and Operation Manual
Section 3 Rev: 1.00 Issue 4 Page 3-3
3.3.2 Transmit Selector Switch
Transmit Selector Switch TX Indicator
Figure 3: Transmit Select Switch
The transmit selector switch is a six position switch used to select the desired transceiver. For the AA95
and AA96, this switch typically selects the PA function when rotated fully clockwise. When the hand mic
or transmit PTT switch is activated, the mic will be coupled to the radio (or PA) selected. The pilot has
priority over the copilot during transmit operations.
Receive audio for the transceiver selected is automatically activated as a function of the rotary selector
switch and no additional switching is needed to establish outside communication. During transmit, all
audio selected is muted except the sidetone of the transceiver in use. In the AA95 and AA97’s, Direct
Audio 2 also remains un-muted during transmit.
The front panel TX indicator will illuminate green when either the pilot or co-pilot transmits. It will not light
when the hand mic (if installed) is used.
3.3.3 ICS Functions
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.
Mode Switch ICS Mode Switch VOX Squelch
Control
ICS Volume
Control
Figure 4: ICS Switches
ENG-FORM: 806-0111.DOT
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