Northern Airborne Technology AA22 User Manual
Installation and Operation Manual
AA22 Series
PA Driver/Siren Control
SM33-2
ISSUE 4.01
Northern Airborne Technology Ltd.
1925 Kirschner Road
Kelowna, BC, Canada.
V1Y 4N7
Telephone (250) 763-2232
Facsimile (250) 762-3374
Issued on the authority of Northern Airborne Technology Ltd.
Copyright 2008
AA22 Series PA Driver/Siren Control
SM33-2 Installation and Operation Manual
IMPORTANT INFORMATION
This manual has been produced to provide information unique to the AA22 Series PA
Driver/Siren Control. Some of this information has been published previously in the SM02
Service manual (AA20/22/23 PA110/220 Series Loudhailer / PA systems).
Earlier versions of the AA22 may not be covered by the information in this manual.
Please refer to SM02, or contact the Technical Support Department at NAT Ltd.
Installation and Operation Manual Page ii
ENG-FORM: 820-0114.DOT
CONFIDENTIAL AND PROPRIETARY TO NORTHERN AIR BORNE TECHNOLOGY LTD.
AA22 Series PA Driver/Siren Control
SM33-2 Installation and Operation Manual
Prepared By: Checked By: Approved By:
The status of this installation and operation manual is controlled by issue shown on the title page. The
status of each section is controlled by revision shown in the footer of each page. All revisions affecting
sections of this manual have been incorporated into the latest issue.
ISSUE/REVISION RECORD
Manual Issue
Number
Section
Revision Number
Revision Description Issue Date
4.01 Section 1 Rev: 1.00
Section 2 Rev: 1.00
Section 3 Rev: 1.00
Update to current templates.
Updated Section 2 with the latest
drawings.
Jun 25, 2008
Installation and Operation Manual Page iii
ENG-FORM: 820-0114.DOT
CONFIDENTIAL AND PROPRIETARY TO NORTHERN AIR BORNE TECHNOLOGY LTD.
AA22 Series PA Driver/Siren Control
SM33-2 Installation and Operation Manual
Table of Contents
Section Title Page
1. Description
1.1 Introduction 1-1
1.2 Product Description 1-1
1.3 Design Features 1-1
1.4 Specifications 1-1
1.4.1 Electrical Specifications 1-1
1.4.2 Physical Specifications 1-2
1.4.3 Environmental Specifications 1-2
1.5 Unit Nomenclature 1-2
2. Installation
2.1 Introduction 2-1
2.2 Unpacking and Inspection 2-1
2.2.1 Warranty 2-1
2.3 Continued Airworthiness 2-1
2.4 Installation Procedures 2-2
2.4.1 Warnings 2-2
2.4.2 Cautions 2-2
2.4.3 Cabling and Wiring 2-2
2.4.4 Post Installation Checks 2-3
2.5 Adjustments and Connections 2-4
2.6 Accessories Required But Not Supplied 2-5
2.7 Installation Drawings 2-5
3. Operation
3.1 Introduction 3-1
3.2 General Information 3-1
3.3 Controls and Indicators 3-1
3.3.1 Power Up 3-1
3.3.2 Mode Switch 3-1
3.3.3 Volume Control 3-2
3.3.4 Siren Button 3-2
3.3.5 Remote Power Switch 3-2
Installation and Operation Manual Page iv
ENG-FORM: 820-0114.DOT
CONFIDENTIAL AND PROPRIETARY TO NORTHERN AIR BORNE TECHNOLOGY LTD.
AA22 Series PA Driver/Siren Control
SM33-2 Installation and Operation Manual
Section 1 Description
1.1 Introduction
Information in this section consists of product description, design features and specifications for the AA22
Series PA Driver/Siren Control. All derivative product information shall be contained in the applicable
manual supplement, which may be obtained from NAT as required.
Review all notes, warnings and cautions.
1.2 Product Description
The AA22 Series PA Driver/Siren Control is a compact, self-contained, Dzus-mounted unit. The AA22 is a
line driver for remote mounted power amplifiers. The AA22-110 or AA22-160 is typically used with the
PA110 or PA220, while the AA22-492 or AA22-493 is typically used with the PA250 or PA700.
1.3 Design Features
Microphone interfacing is accomplished from either an AA9x/AMS4x series audio controller, or a ‘carbon
equivalent’ microphone. A radio audio input is provided to allow for radio 'rebroadcast' operation. The
siren is adjustable for tone, rate and level. Provision is made for external power switching to activate
PA110/220 power amplifiers.
All external connectors, switches and relay contacts are gold plated for maximum reliability. Switches and
relays are sealed. G10-FR flame retardant circuit boards are post coated for maximum moisture
resistance and corrosion prevention. Relays are sealed, high vibration rated (50g shock) and dry nitrogen
filled.
1.4 Specifications
1.4.1 Electrical Specifications
Power +22 to 32 Vdc (28 Vdc nom) at 250 mA max (excl. lamps).
Internally grounded case
Panel Lamps 2 ea. type #387 for 28 Vdc operation
Maximum lamp load 80 mA
Inputs
Mic 0.25 Vrms at 150 Ω
PA and Radio 2.5 Vrms at 3.3 Ω
Circuitry Single-ended
Microphone Industry standard ‘carbon equivalent’ or amplified dynamic
microphone preferred
Min. 200 mV output required into 150 Ω
David Clark M1/DC, M4, M7 recommended
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AA22 Series PA Driver/Siren Control
SM33-2 Installation and Operation Manual
Impedance 1 kΩ
Output 6 Vrms @ 1 kHz into 600 Ω ground referenced
Circuitry Single-ended
Power Key Switched +28 Vdc available to activate remote amplifiers
Key Logic Ground-seeking inputs for all lines
1.4.2 Physical Specifications
Height 1.11" (29.2 m m)
Depth 6.32" (160.5 mm) behind panel, excluding mating connectors
Width 5.75" (146.1 mm) front panel
4.96" (126.0 mm) rear enclosure
Mounting Standard Dzus Mounting (four fasteners)
Weight 1.00 lbs (0.45 kg) excluding mating connector
1.4.3 Environmental Specifications
Temperature -20 to +55°C (ambient)
Altitude 25,000 feet max.
Humidity 95%
Shock 12g (any axis)
Qualification DO-160C Env. Cat. B1-BA[MN]XXXXXXABBBBXXXXX
1.5 Unit Nomenclature
AA22-110 Standard swe pt siren, adjustable rate/tone
Mode select switch, PA/Radio monitor
>50 mW output into 150 Ohms
6 Vrms nominal siren output into 600 Ohms
70 mA nominal current consumption
PA and Siren override at all times
+28 Vdc switched power output
Use with PA110 and PA220 series amplifiers
AA22-160 Wail/Yelp swept siren, adjustable rate/tone
Mode select switch, PA/Radio monitor
6 Vrms nominal audio output into 600 Ohms
6 Vrms nominal siren output into 600 Ohms
70 mA nominal current consumption
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CONFIDENTIAL AND PROPRIETARY TO NORTHERN AIR BORNE TECHNOLOGY LTD.
AA22 Series PA Driver/Siren Control
SM33-2 Installation and Operation Manual
+28 Vdc switched power output
Use with PA110 and PA220 series amplifiers
Can be selected as a radio with keyline serving as siren key
AA22-163* Same as AA22-160, with locking PA/RADIO select switch
AA22-165* Same as AA22-160, with 28 Vdc NVG-suitable lighting
AA22-167* Same as AA22-160, with 5 Vdc NVG-suitable lighting
AA22-170* Same as AA22-163, with 28 Vdc NVG-suitable lighting
AA22-492 Wail/Yelp swept siren, adjustable rate/tone
Mode select switch, PA/Radio monitor
500 mVrms nominal audio output into 600 Ohms
450 mVrms nominal siren output into 600 Ohms
Siren override at all times
70 mA nominal current consumption
Used with PA250 and PA700 series amplifiers
Can be selected as a radio with keyline serving as siren key
AA22-493 Wail/Yelp swept siren, adjustable rate/tone
Mode select switch
100 mVrms nominal audio output into 600 Ohms
90 mVrms nominal siren output into 600 Ohms
Siren override at all times
80 mA nominal current consumption
Used with PA250 and PA700 series amplifiers
Can be selected as a radio with keyline serving as siren key
AA22-495* Same as AA22-492, with 28 Vdc NVG-suitable lighting
AA22-592* Same as AA22-492, with 5 Vdc lighting
AA22-594* Same as AA22-492, with 5 Vdc NVG-suitable lighting
* These products are included in this section for reference only. For more detailed information on
these and other AA22 products, contact the Product Support Department at NAT Ltd.
Section 1 ends
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CONFIDENTIAL AND PROPRIETARY TO NORTHERN AIR BORNE TECHNOLOGY LTD.
AA22 Series PA Driver/Siren Control
SM33-2 Installation and Operation Manual
Section 2 Installation
2.1 Introduction
Information in this section consists of unpacking and inspection procedures, installation procedure s, po stinstallation checks and installation drawings for the AA22 Series PA Driver/Siren Control.
Review all notes, warnings and cautions.
2.2 Unpacking and Inspection
Unpack the equipment carefully and locate the warranty card. Inspect the unit visually for damage due to
shipping and report all such claims immediately to the carrier involved. Check that all items listed below
are present before proceeding and report any shortage immediately to your supplier:
- Warranty Card
- Operators Manual
- Certificate of Conformity or Release Certification
2.2.1 Warranty
All Northern Airborne Technology Ltd. products are warranted for 2 years from date of installation by an
authorized NAT dealer, to be free of defects in workmanship or performance. This warranty covers all
materials and labour, but is exclusive of any transport to deliver the defective unit to and from NAT or its
designated warranty repair center, or any labour to remove or re-install the defective unit in the aircraft.
Contact NAT for any questions regarding this warranty, its applicability to your units and/or for return
authorization. NAT is the final arbitrator concerning warranty administration. Units which have been
physically damaged, burned, immersed in water or otherwise abused beyond the scope of normal use will
not be considered for warranty. WARRANTY IS VOID UNLESS THE PRODUCT IS INSTALLED BY AN
AUTHORIZED NAT DEALER. Product for which a warranty card is not returned shall be warranted from
date of manufacture.
2.3 Continued Airworthiness
Maintenance of the AA22 Series PA Driver/Siren Control is ‘on condition’ only. Periodic maintenance of
this product is not required.
Section 2 Rev: 1.00 Issue 4 Page 2-1
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CONFIDENTIAL AND PROPRIETARY TO NORTHERN AIR BORNE TECHNOLOGY LTD.
AA22 Series PA Driver/Siren Control
SM33-2 Installation and Operation Manual
2.4 Installation Procedures
2.4.1 Warnings
High volume settings can cause hearing damage.
Set the headset volume control to the minimum volume setting prior to
conducting tests, and slowly increase the headset volume to a
comfortable listening level.
2.4.2 Cautions
Never ground any output line from the AA22 or permanent damage may
result. Use of a fully floating audio wattmeter or transformer-coupled meter is
recommended. Always check ADF and compass calibration after installing
external speakers or "PA" amplifiers. Significant single cycle errors may be
caused by the concentration of steel and magnetic material.
WARNING:
CAUTION:
2.4.3 Cabling and Wiring
All wire shall be selected in accordance with the original aircraft manufacturer's Maintenance Instructions
or AC43.13-1B Change 1, Paragraphs 11-76 through 11-78. Unshielded wire types shall qualify to
MIL-W-22759 as specified in AC43.13-1B Change 1, Paragraphs 11-85, 11-86, and listed in Table 11-11.
For shielded wire applications, use Tefzel MIL-C-27500 shielded wire with solde r sleeve s (fo r shield
terminations) to make the most compact and easily terminated interconnect. Follow the connector map in
Section 2.7 as required.
Allow 3" from the end of the shielded wiring to the shield termination to allow the connector hood to be
easily installed. Reference the interconnect drawing in Section 2.7 for shield termination details. Note that
the hood is a "clamshell" hood, and is installed after the wiring is complete. Aircraft harnessing shall
permit the unit to be lowered from the panel for easy access to all side adjustments. Do NOT mount the
unit until all adjustments have been performed.
Maintain wire segregation and route wiring in accordance with the original aircraft manufacturers
Maintenance Instructions.
Unless otherwise noted, all wiring shall be a minimum of 22 AWG, except power and ground lines, which
shall be a minimum of 20 AWG. Reference the Interconnect drawing for additional specifications. Check
that the ground connection is clean and well secured, and that it shares no path with any electrically noisy
aircraft accessories such as blowers, turn and bank instruments or similar loads. Power to this unit must
be supplied from a separate circuit breaker or fuse (fast blow), and not attached to any other circuit
breaker without additional protection. Verify that the selected circuit breaker size and wire gauge are
adequate for the installation using the techniques specified in AC43.13-1B Change 1, Paragraphs 11-47
through 11-51 and 11-66 through 11-69.
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CONFIDENTIAL AND PROPRIETARY TO NORTHERN AIR BORNE TECHNOLOGY LTD.
AA22 Series PA Driver/Siren Control
SM33-2 Installation and Operation Manual
2.4.4 Post Installation Checks
2.4.4.1 Voltage/Resistance Checks
Do not attach the AA22 until the following conditions are met.
Check the following:
a) Check P101, pin 1 and 2 for +28 Vdc relative to ground.
b) Check P101, pin 14, 15 and 16 for continuity to ground (less than 0.5Ω).
c) Check P101, pin 3 for the presence of the lamp dimmer voltage.
Check the following for AA20-030 and AA20-430
d) Check P101, pin 10 for continuity to ground (less than 0.5Ω). This ground is installation
specific and may be a 'hard' ground or supplied by a momentary switch (siren trigger).
2.4.4.2 Operational Checks
The PA system is not intended to be operated in a linear volume manner (i.e., it is not like a
stereo system). The PA is designed to provide high levels of audio power under difficult
conditions and does so by sacrificing some of the high fidelity for a higher average power output.
The volume control on the AA22 is not intended to provide linear operations from the PA system
and will result in broken and sporadic output from the PA when insufficient levels are delivered to
the AA22 and/or to the power amplifier unit from the AA22.
For most RADIO and PA (voice) operations, it is suggested that the AA22 volume control be set
to maximum (fully cw). If the system is overdriving, reduce the AA22 volume setting.
To check the system, the aircraft must be moved outside and away from as many reflective
surfaces as possible. It is not recommended to operate the PA microphone on the ground, as a
high risk exists for audio coupling and feedback. However, if the test is to be conducted on the
ground, the aircraft should be positioned on a grassy surface to help reduce the distortion
produced by sound reflected from concrete or asphalt. It is also beneficial to stuff the speaker
projectors with soft rubberized foam to reduce the risk of feedback and distortion.
Advise all nearby personnel that PA system tests are to be done.
Start by checking the Siren Circuit for proper operation and tone/rate adjustment. The Siren
always operates at 100% output from the AA22 and should drive the PA's to full output on audio
peaks. The Level trimpot of the AA22 will be set at the factory to provide rated output at full front
panel volume control adjustment.
Once the siren operation is satisfactory, you may try RADIO operations through the AA22. To
achieve full output capability from the AA22, a signal of 2.5 Vrms must be delivered to the AA22
Radio audio input and the AA22 volume must be set to maximum. Lower levels of input signal or
volume settings will result in poor output audio (very broken).
For PA (voice) tests, it is best that the aircraft is flown in an approximately 200 foot hover and
commands are given to a human ground target for visual response to the commands. Remember,
the human target should be positioned in the area that the speaker system is designed to project
the audio to. This will depend on speaker orientation and the height of the aircraft. Remove all
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AA22 Series PA Driver/Siren Control
SM33-2 Installation and Operation Manual
sound absorbing material from the speakers before flying the aircraft. To achieve the best
operation, all voice commands must be spoken slowly and clearly, with extra emphasis on each
word.
To determine the operational capability of the system, put the aircraft in a hover and with the
target properly positioned, provide PA instruction to the target to accomplish a certain task that
will give visual cue to the flight crew that the target has understood the instructions (i.e., "touch
your head", "sit down", "turn around", etc.)
2.4.4.3 Power On Checks
Power up the aircraft’s systems and confirm normal operation of all functions of the AA22. Refer to
Section 3 (Operation) for specific operational details.
a) Turn on all of the radios and other accessories required for this system. Check that the power
ON LED on the AA22 illuminates when the power switch is up.
b) Key the siren using the front panel button or remote siren key. The siren should sound and
the level should be at maximum volume (the front panel level control does not affect the
siren). If the siren (rate or tone) needs adjustment there are two trimpots on the left side of
the AA22.
c) Select the rest of the audio system as required to allow connection of the pilot's mic to the
‘PA’ and key the cyclic switch for transmit. The mic audio should be heard on the ‘PA’
speakers. Adjust the front panel level control for the desired volume.
d) Check preset adjustments are completed before aircraft departure.
Notes: 1. Note that PA audio has priority in the AA22 system and it will be heard even if the panel
switch is selected to ‘RADIO’. Check for correct radio operation and note what volume
settings will produce a suitable external paging level..
2. A faint audio signal may be heard at the speaker (even when the system is not paging) due to
the very high gain of this system and stray coupling in the wiring. It should not be audible in
flight.
Upon satisfactory completion of all performance checks, make all required log book entries, electrical
load, weight and balance amendments and other documentation as required by your local regulatory
agency before releasing the aircraft for service.
2.5 Adjustments and Connections
If any preset requires adjustment, be sure this is carried out before the aircraft leaves and that the unit
and its mating connector are secured before departure.
If the siren does not suit the specific requirements of a given installation, the following adjustments are
available:
1. Base tone setting - potentiometer marked TONE.
2. Sweep rate setting - potentiometer marked RATE.
These controls are accessible through holes on the left side of the unit as shown in Figure 1.
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AA22 Series PA Driver/Siren Control
SM33-2 Installation and Operation Manual
Siren Rate Siren Tone
Master Level
Figure 1: Tone and Rate Controls
2.6 Accessories Required But Not Supplied
Installation kit p/n AA20-IKC (crimp) is required to complete the installation.
AA20-IKC 25-pin D-min Female Crimp Kit (NAT Part No. D25SL-IKC) consists of
Quantity Description NAT Part No.
1 D-min 25 Socket Housing 20-21-025
25 MS Crimp Socket 20-26-901
1* Jack Screw Set 20-27-002
1* Lock Clip Set 20-27-004
1 50 Pin Connector Hood 20-29-026
* Use as required.
2.7 Installation Drawings
Use of the "#" symbol in the REV. column indicates that the document is listed elsewhere in the manual.
Refer to the applicable NAT Part No. to locate the referenced document.
DOCUMENT REV. DESCRIPTION TYPE SERIAL NO.
AA22-110
AA22\110\403-0 1.02 PA Driver/Siren System Interconnect Up to 4019
AA22\110\403-0 1.10 PA Driver/Siren System Interconnect 4020 and up
AA22\110\405-0 1.02 PA Driver/Siren System Connector Map All
AA22\110\905-0 1.02 PA Driver/Siren System Faceplate Up to 4126
AA22\110\905-0 1.10 PA Driver/Siren System Faceplate 4127 and up
AA22\160\922-0 1.00 PA Driver/Siren System Mechanical Installation All
AA22-160
AA22\160\403-0 1.01 PA Driver/Siren System Interconnect Up to 2900
AA22\160\403-0 1.10 PA Driver/Siren System Interconnect 2901 and up
AA22\160\405-0 1.02 PA Driver/Siren System Connector Map All
AA22\160\905-0 1.02 PA Driver/Siren System Faceplate Up to 4126
AA22\160\905-0 1.10 PA Driver/Siren System Faceplate 4127 and up
AA22\160\922-0 # PA Driver/Siren System Mechanical Installation
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