Northern Airborne Technology AA22 - Manual (Page 38)

AA22 Series PA Driver/Siren Control
SM33-2 Installation and Operation Manual
Section 3 Rev: 1.00 Issue 4 Page 3-2
ENG-FORM: 806-0111.DOT
CONFIDENTIAL AND PROPRIETARY TO NORTHERN AIRBORNE TECHNOLOGY LTD.
3.3.2.2 Radio Operation
To set the system for radio rebroadcast functions, set the Mode switch on the AA22 to RADIO. All audio
delivered from the source (typically pilot’s or copilot’s headset) will be broadcast through the PA system, if
provision for this is made at the time of installation.
3.3.3 Volume Control
The VOL control pot on the front of AA22 sets the volume level. For external loudhailer and rebroadcast
operations, the volume should always be set between half and full level.
3.3.4 Siren Button
3.3.4.1 AA22-110
The siren is activated by depressing the momentary push-button SIREN control on the front of the AA22,
or by using a remote keying switch. The siren will sound only as long as the button is depressed. Level
setting is automatic and need not be adjusted.
3.3.4.2 AA22-160, AA22-492 and AA22-493
On these models, the front-panel SIREN button is replaced by a WAIL/OFF/YELP switch. This allows the
operator to disable the siren, or select the required siren mode from the front panel of the AA22.
3.3.5 Remote Power Switch
Remote power switching for the power amplifiers is provided as a switched +28 Vdc output from the
AA22.
Section 3 ends