Northern Airborne Technology AA38-3xx User Manual

Installation and Operation Manual

AA38-3xx Series

Local ICS Loop

SM37

ISSUE 4.11

Northern Airborne Technology Ltd.

1925 Kirschner Road

Kelowna, BC, Canada.

V1Y 4N7

Telephone [phone]

Facsimile [phone]

Issued on the authority of Northern Airborne Technology Ltd.

Copyright 2004

AA38-3xx Series Local ICS Loop

SM37 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 1-3

1.4.3 Environmental Specifications 1-3

1.4.4 Product Approval 1-3

1.5 Unit Nomenclature 1-3

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 Cautions 2-2

2.4.2 Cabling and Wiring 2-2

2.4.3 Installation Options 2-2

2.4.4 Post-Installation Checks 2-4

2.5 Adjustments and Connections 2-4

2.5.1 Audio Levels 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

Installation and Operation Manual Page iii

ENG-FORM: 820-0114.DOT

CONFIDENTIAL AND PROPRIETARY TO NORTHERN AIR BORNE TECHNOLOGY LTD.

AA38-3xx Series Local ICS Loop

SM37 Installation and Operation Manual

Section 1 Description

1.1 Introduction

Information in this section consists of product description, design features and specifications for the
AA38-3xx Series Local ICS Loop. 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 AA38-300 Local ICS Loop provides intercom functions for eight users with operation in HOT MIC or
VOX mode. A switch-selectable NAT or Andrea tie line allows connection to multi-unit systems and radio
or music can be connected at the AUX input.

The AA38-301 Local ICS Loop is functionally identical to the AA38-300 but has two fully independent
AA38-300 PCB assemblies mounted inside the enclosure and can therefore provide the same intercom
functions for sixteen users.

1.3 Design Features

The AA38-3xx Series remote bulkhead mounted units contain all the circuitry to support a wide variety of
ICS Loop applications, particularly isolation/ICS amplifier use, where the output is required to be headset
or line level.

The compact size and low weight of the AA38 allows mounting in restricted locations and the mapped
interconnect makes installation simple to carry out.

Built-in LED annunciators speed up airframe trouble-shooting by providing an indication of power to the
AA38 and VOX operation.

Level adjustments are provided for ICS level and AUX Input level.

1.4 Specifications

1.4.1 Electrical Specifications

Input Power

Input Voltage 27.5 Vdc, with reverse and over-voltage protection

32.2 Vdc max.
Input Current 0.66 Amps Max. @ 27.5 Vdc

Section 1 Rev: 1.00 Issue 4 Page 1-1

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CONFIDENTIAL AND PROPRIETARY TO NORTHERN AIR BORNE TECHNOLOGY LTD.

Input Signals

Quantity 8 Mic channels
(AA38-300) 1 ICS tie channel
1 Aux input channel

Quantity 16 Mic channels
(AA38-301) 2 ICS tie channels
2 Aux input channels

Audio Level 250 mVrms for mic inputs

0.34 Vrms for NAT ICS tie input

2.8 Vrms for Andrea ICS tie input

2.5 Vrms for Aux input
Impedance 150 Ω ±10% for mic inputs

1.6k Ω ±10% for NAT ICS tie input
250 Ω ±10% for Andrea tie input
940 Ω ±10% for Aux input

Circuitry Type All mics are single-ended inputs
Tie lines are single-ended inputs
Aux line is single-ended input
Better than -60 dB input-to-input crosstalk (Mic to Aux to ICS)

Output Signals

Quantity 8 Headset outputs
(AA38-300)

Quantity 16 Headset outputs
(AA38-301)

Rated Level Headset output 7.7V rms or 100 mW (20 dBm) into 600 Ω
Impedance 30 Ω ±10%. (Headset output)
Circuitry Type Balanced output for high common mode noise rejection

Audio Frequency Response

Intercom <3 dB from 350 Hz to 3000 Hz
RX <3 dB from 350 Hz to 6000 Hz
Distortion <10% THD @ Rated power output
Audio Noise Level >60 dB down from rated output (without signal)
Output Regulation <10% distortion / Δ3 dB max. of rated output power at 400% and

AA38-3xx Series Local ICS Loop

SM37 Installation and Operation Manual

75% of rated load

Section 1 Rev: 1.00 Issue 4 Page 1-2

ENG-FORM: 800-0114.DOT

CONFIDENTIAL AND PROPRIETARY TO NORTHERN AIR BORNE TECHNOLOGY LTD.

AA38-3xx Series Local ICS Loop

SM37 Installation and Operation Manual

1.4.2 Physical Specifications

AA38-300 AA38-301

Height

Max.
Depth 4.60" (116.8 mm) max. including connector
Width 4.50" (114.3 mm) max. including flanges

Weight

Max.

Mounting Bulkhead mount with four 10-32 screws

Material/

Finish

Connectors Filtered male 37-pin D-subminiature.

connector with jack posts.

1.31"

(33.3 mm)

0.55 lbs

(0.25 Kg)

5052-H32 brushed aluminum with chromate conversion finish

Two filtered male 37-pin

D-subminiature. connector with

2.31”

(58.7 mm)

1.01 lbs

(0.45 Kg)

jack posts.

1.4.3 Environmental Specifications

Temperature -30 to +55°C (operating)

-55 to +85°C (survival)
Altitude 25,000 feet max.
Humidity 95%

Qualification of the AA38-300 Local ICS Loop was completed in accordance with
DO-160C Env. Cat. B4-CA[BMN]XXXXXXZBABBTZXXX.

Note: Refer to Environmental Qualification Form located in Section 2 of this Manual for complete details

of the environmental categories.

1.4.4 Product Approval

FAA: TSO-C50c (RTCA/DO-170 Class 1a)

Note: Applicable to AA38-300 and AA38-301 units serial number 3000 and up.

1.5 Unit Nomenclature

AA38-300 Intercom functions for eight users
Selectable NAT ICS or Andrea Tie Line
ICS volume, AUX volume and VOX controls
Live and VOX Intercom modes
VOX operation LED and 28 Vdc Power LED

Section 1 Rev: 1.00 Issue 4 Page 1-3

ENG-FORM: 800-0114.DOT

CONFIDENTIAL AND PROPRIETARY TO NORTHERN AIR BORNE TECHNOLOGY LTD.

AA38-3xx Series Local ICS Loop

SM37 Installation and Operation Manual

AA38-301 Intercom functions for sixteen users
Selectable NAT ICS or Andrea Tie Lines
ICS volume, AUX volume and VOX controls
Live and VOX Intercom modes
VOX operation LED and 28 Vdc Power LED

Section 1 ends

Section 1 Rev: 1.00 Issue 4 Page 1-4

ENG-FORM: 800-0114.DOT

CONFIDENTIAL AND PROPRIETARY TO NORTHERN AIR BORNE TECHNOLOGY LTD.

AA38-3xx Series Local ICS Loop

SM37 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 AA38-3xx Series Local ICS Loop.

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

- 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 AA38-3xx Series Local ICS Loop is ‘on condition’ only. Periodic maintenance of this
product is not required.

Section 2 Rev: 1.00 Issue 4 Page 2-1

ENG-FORM: 805-0117.DOT

CONFIDENTIAL AND PROPRIETARY TO NORTHERN AIR BORNE TECHNOLOGY LTD.