Northern Airborne Technology AA22 - Manual (Page 37)

AA22 Series PA Driver/Siren Control
SM33-2 Installation and Operation Manual
Section 3 Rev: 1.00 Issue 4 Page 3-1
Section 3 Operation
3.1 Introduction
Information in this section consists of functional and operational procedures for the AA22 Series PA
Driver/Siren Control.
3.2 General Information
The AA22 PA Driver/Siren Control provides a central adjustment for external aircraft loudhailer functions.
The AA22 is only a line driver and must have at least one external amplifier in the system. When turned
on, the system is ready for operation and will accept audio feeds or a microphone input. An internally
generated siren is also available and adjustable through the side of the controller. When the AA22 is
turned on, a ‘POWER KEY’ signal is generated. This signal is used to turn on the ‘PA’ amp. The high
current DC to operate the PA110/220 is supplied by the aircraft.
3.3 Controls and Indicators
3.3.1 Power Up
To activate the AA22 PA Driver/Siren Control, flip the POWER toggle switch up, to the ON position. The
LED adjacent to the switch should illuminate.
POWER
Switch
Volume
Control
Mode
Switch
Siren Button ‘Power On’
LED
3.3.2 Mode Switch
The Mode switch is a two-position toggle switch used to select between PA and Radio operation.
3.3.2.1 PA Operation
For external loudhailer systems, set the Mode switch on the AA22 to PA. Key the microphone through the
cyclic switch or hand mic switch, and speak in a firm, clear manner. For best results, over-emphasize
each word.
ENG-FORM: 806-0111.DOT
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