Bose Headphones A20 User Guide page

A20 AVIATION HEADSET

Owner’s Guide

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English

SAFETY INFORMATION

NOTE: This equipment has been tested and

Important Safety Instructions

found to comply with the limits for a Class B

digital device, pursuant to Part 15 of the

FCC Rules. These limits are designed to

provide reasonable protection against

harmful interference in a residential

•

Please read these instructions carefully

and completely before using the headset.

•

Keep these instructions and make these

instructions easily accessible to all users

at all times. Always include these

instructions when passing the headset

on to third parties.

installation. This equipment generates, uses,

and can radiate radio frequency energy and,

if not installed and used in accordance with

the instructions, may cause harmful

interference to radio communications.

However, there is no guarantee that

interference will not occur in a particular

installation. If this equipment does cause

harmful interference to radio or television

reception, which can be determined by

turning this equipment off and on, the user is

encouraged to try to correct the interference

by one or more of the following measures:

•

During flight operations, do not use the

headset for telephone calls.

It is the responsibility of each aircraft

operator or pilot in command to

determine that any and all portable

devices will be free of any interference

with the navigation or communication

system of the aircraft. In addition, it is

their responsibility to determine the

suitability of the performance of portable

devices in relation to the use of the

Bose^®A20^®Aviation Headset.

– Re-orient or relocate the receiving

antenna.

– Increase the separation between this

equipment and receiver.

– Connect this equipment into an outlet on

a circuit different from that to which the

receiver is connected.

– Consult Bose or an experienced radio/TV

technician for help.

Changes or modifications not expressly

approved by Bose Corporation could void

the user’s authority to operate this

equipment.

•

The headset is capable of producing

sound pressure levels exceeding

85dB(A). In many countries 85dB(A) is

the maximum legally permissible level for

continuous noise exposure during the

working day. Exposure to sounds of

higher volume levels or longer durations

can permanently damage your hearing.

•

Never repair or attempt to repair a

defective headset yourself. Contact

Bose^®Technical Support. Refer to

“Contact information” on page 37.

Operation is subject to the following two

conditions: (1) This device may not cause

harmful interference, and (2) this device

must accept any interference received,

including interference that may cause

undesired operation.

Do not immerse the headphones in water

or any other liquid. See “Cleaning the

headset” on page 23 for cleaning

instructions.

Warning: Choking

hazard. Keep the

batteries away from

children.

This device complies with FCC and Industry

Canada RF radiation exposure limits for

general population. It must not be collocated

or operating in conjunction with any other

antenna or transmitter.

Danger of explosion if

batteries are incorrectly replaced.

Replace only with AA alkaline

batteries. Do not use any other

battery chemistries.

Batteries may cause a fire or chemical

burn if mishandled. Do not recharge,

disassemble, heat, or incinerate.

Dispose of used batteries properly.

Bose Corporation hereby declares

that this product is in compliance

with the essential requirements

and other relevant provisions of

Directive 1999/5/EC and all other

applicable EU directive

requirements. The complete

declaration of conformity

can be found at:

www.Bose.com/compliance.

Operate this product within the temperature

range of 5°F to 131°F (-15°C to 55°C) only.

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English

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CONTENTS

ADVISORIES

Operational advisory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Hearing safety . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Volume control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

Recognizing aircraft sounds . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

Using audio sources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

Headset earcup requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Earcup inner screen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

INTRODUCTION

What’s included . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

What’s in the carton . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Control module variations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Power and cable variations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

PREPARING THE HEADSET FOR USE

The microphone assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Attaching the microphone assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

The battery compartment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Opening the battery compartment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

The operation switches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Inserting and replacing the batteries . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

Connecting the headset to the aircraft . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

Using the 6-pin plug . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

Using the dual general aviation plugs . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Using other plug types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

USING THE HEADSET

Wearing and adjusting the headset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Conditions related to fit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Microphone placement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Clothing clips . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Using the control module . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

Power button . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

Volume control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

Power indicator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

Auxiliary (AUX) audio input . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

Audio priority . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

Using the headset with a Bluetooth^®-enabled phone . . . . . . . . . . . . . . . . 19

Pairing the headset with your phone . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

Bluetooth^®volume control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

Making and answering calls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

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CONTENTS

English

HEADSET CARE AND MAINTENANCE

Instructions for continued airworthiness . . . . . . . . . . . . . . . . . . . . . . . . . 23

Cleaning the headset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

General cleaning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

Headset earcup openings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

Microphone windscreen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

Earcup inner screen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

Headband cushion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

Replacing parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

Microphone windscreen replacement . . . . . . . . . . . . . . . . . . . . . . . . . . 24

Ear cushion replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

Battery replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

Headband cushion replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

Microphone assembly or access cover replacement . . . . . . . . . . . . . . 26

Storage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

TROUBLESHOOTING

In case of difficulty . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

INSTALLATION

Mounting the aircraft panel connector . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

Details on making the connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

TECHNICAL INFORMATION

SERVICE AND WARRANTY INFORMATION

Locating the headset serial number . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

Warranty period . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

Limited warranty service . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

To return your headset to Bose for repair . . . . . . . . . . . . . . . . . . . . . . . 36

Contact information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

Ordering parts and accessories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

iii

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English

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ADVISORIES

Operational advisory

The Bose^®A20^®Aviation Headset incorporates Acoustic Noise Cancelling^®

technology. As with any complex electronic device, it is possible for this

headset to fail during operation. Symptoms of failure may include loud tones,

distortion, and loss of communications signal in the headset when used in the

Acoustic Noise Cancelling mode.

Note: The headset includes redundant circuitry to reduce the effects of such failures

and to allow for continued use of the headset in the passive noise reducing mode.

In passive noise reducing mode, the volume controls on the control module will

automatically be set to maximum volume. If additional volume control is

needed, you can use the intercom or radio volume control.

Acoustic Noise Cancelling mode is active when the headset control module is

powered on (power indicator is lit). The headset is in the passive mode when

the power is off (power indicator is not lit). See “Control module variations” on

page 6.

If your headset is aircraft powered, connect the headset to the aircraft power

sources only as described in “Connecting the headset to the aircraft” on

page 11. The headset will not operate properly if used with any battery source

other than the Bose A20 Aviation Headset control module.

Note: In the unlikely event of a headset issue, we suggest that you switch to an

alternate communications method and use standard cockpit resource

management skills to minimize distractions.

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ADVISORIES

English

Hearing safety

The headset is intended for use with the Acoustic Noise Cancelling^®mode

turned on. Noise reduction and communications performance are reduced with

Acoustic Noise Cancellingmode turned off.

Volume control

Make sure your aircraft communications system volume control is easily

accessible. This control affects the strength of the communications signal

coming into the headset.

As pilot in command, you must be sure you can understand critical

communications even with Acoustic Noise Cancellingmode turned off. In this

case, you may need to turn up the aircraft communications system volume.

Avoid setting the volume controls at levels high enough to impair your hearing

during extended periods of headset use.

Recognizing aircraft sounds

With the headset’s active and passive noise reduction, typical aircraft sounds

(such as engines, propellers, warning alarms, and other sound sources) may

not sound familiar. We strongly advise you to make sure you can hear and

recognize these sounds when using the Bose^®A20^®Aviation Headset while

operating any aircraft.

Using audio sources

When listening to in-flight entertainment, or a portable audio source through a

Bose A20 Aviation Headset, be sure to limit the volume to safe levels that do

not interfere with your ability to hear informational sounds and warning alarms,

such as stall warnings or gear up, while piloting.

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English

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ADVISORIES

Headset earcup requirements

Proper headset operation requires that the headset TriPort^®openings on the

earcup are kept free of debris. The headset TriPort openings are located on the

outside of each earcup and include two holes and a screen.

TriPort

opening

Microphone

opening

Earcup inner screen

The protective inner screen is critical to the headset’s performance.

Earcup

inner screen

Do not attempt to remove, replace, or repair this screen. If screen replacement

seems necessary, contact Bose^®Technical Support. See “Contact information”

on page 37.

If the screen gets wet or any foreign objects become lodged on or adjacent to

it, follow the instructions in “Headset Care and Maintenance” on page 23.

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INTRODUCTION

Congratulations on your purchase of a Bose^®A20^®Aviation Headset. The Bose

A20 Aviation Headset is our most advanced aviation headset yet. It delivers

significantly increased noise reduction and provides a more comfortable fit,

without compromising the clear audio you expect from Bose. Plus, it offers

auxiliary audio input and is available with Bluetooth^®wireless technology.

What’s included

Each Bose A20 Aviation Headset is supplied with a control module, cable, and

carrying case. The type of control module and end-plug configuration depends

on the options you chose for your headset.

There are two options for the control module:

• Control module with Bluetooth wireless technology

• Conventional control module

There are several end-plug configurations for the headset. Your headset falls

into one of two general categories:

• Battery powered: Operates with battery power only.

• Dual powered: Operates with either aircraft or battery power. No battery

needed when connected to aircraft power.

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INTRODUCTION

What’s in the carton

Headset assembly:

Accessories:

Headphones

Carrying case

Clothing clip

2 AA alkaline

batteries*

Control module

See “Control module

variations” on page 6

for options.

3.5 mm adapter cable

Second clothing clip

Cable connector (varies)

Note: Cable connector types will vary based on model of headset. See “Power

and cable variations” on page 7.

Note: *Replace batteries with alkaline batteries only. Do not use any other battery

chemistries.

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INTRODUCTION

English

Control module variations

If you opted for Bluetooth^®wireless technology, you received the control

module featuring Bluetooth technology. If not, you received the conventional

control module.

Bluetooth control module

Conventional control module

Left/Right volume controls*

Power indicator

Power button

Bluetooth

indicator

Bluetooth

function button

Bluetooth

Volume Up button

Multifunction

switch:

Audio Priority

switch:

Bluetooth

Volume Down button

Top

Intercom

prioritized

Top

Intercom

prioritized

Auxiliary (AUX)

audio input

Middle

Intercom

mixed

Middle

Intercom

mixed

Bottom

Intercom

only

Bottom

Intercom

only

*Control the intercom volume

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INTRODUCTION

Power and cable variations

The Bose^®A20^®Aviation Headset is available for purchase in different standard

aircraft connector options, including:

Battery powered options

Dual powered options

Operate with battery power only

Operate with either aircraft or battery power

No battery needed when connected to aircraft power

Dual G/A

U174

U384

6-pin*

5-pin XLR

8-pin

* An adapter is available from Bose to convert a 6-pin connector to a dual G/A or U174 plug

for additional connection flexibility. Other configurations require the purchase of a cable

assembly.

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English

PREPARING THE HEADSET FOR USE

The microphone assembly

Your headset may be shipped with the microphone assembly (boom microphone

and cable) attached to the left earcup. If your headset is shipped with the

microphone assembly packed separately, you can attach it to either earcup.

Attaching the microphone assembly

Choose the earcup (L or R) to receive the microphone assembly. Also, make

sure that the earcup connector pins are clean and free of debris.

1. Use a Phillips screwdriver to loosen the two screws on the terminator cover

near the bottom of the earcup where you want to attach the

microphone assembly.

2. Remove the terminator cover to reveal the connector pins on the earcup.

3. Carefully line up the microphone assembly to the small connector socket

on the earcup.

4. Slide the connector into the socket until it reaches the stop.

L for left

Connector

Terminator

pins

cover

Microphone assembly

Connector pins

CAUTION: Do not force the connector into the socket, or earcup damage may

occur.

5. Tighten the screws to secure the assembly.

6. Attach the terminator cover to the earcup that does not have the microphone

assembly attached. Insert the screws, then align and tighten them.

Note: The headset will not work without the terminator cover installed.

CAUTION: Be sure to try the headset and fully test its operation before flight.

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PREPARING THE HEADSET FOR USE

The battery compartment

The Bose^®A20^®Aviation Headset is shipped with factory-set operation defaults.

If you want to alter these defaults, you can change the operation switches

located inside the control module battery compartment. If you do not want to

change any of the operation switches, skip ahead to “Inserting and replacing

the batteries” on page 10.

Note: For aircraft-powered versions (5-pin XLR, 6-pin, 8-pin) batteries are not

required for operation.

Opening the battery compartment

You must open the battery compartment to access the operation switches.

Press down firmly on the battery compartment cover finger indent and slide the

cover down. The cover is tethered to the module. Do not attempt to detach it.

Note: The battery compartment cover is designed to remain securely closed. You

may need to use additional force when pressing down and releasing cover.

The operation switches

The operation switches control the Auto Off and Stereo/Mono functions.

Operation switches

To change the operation switches

1. Open the battery compartment.

2. If batteries are installed, remove them. In the battery compartment, you can

observe and change the switch positions.

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PREPARING THE HEADSET FOR USE

English

3. To change a switch position, use a pen or a small, flat-tipped screwdriver to

gently move the switch.

This table shows possible positions, default setting, and purpose for each switch.

Switch

Options

Purpose

1. Auto Off ON, OFF

function

Set at the factory to enable the Auto Off function. The headset

will turn off after 3 to 9 minutes of inactivity. To disable Auto

Off, set the switch to OFF. With the switch in OFF position, the

Acoustic Noise Cancelling^®system will not turn off until you

press and hold the power button for at least one second.

Default: ON

2. Mono/

Stereo

Mono, Stereo

For most configurations, set at the factory for mono audio

systems (to provide audio in both ears). Set it to stereo (ST)

selection Default: MONO if your aircraft has a stereo intercom.

Auto Off functionality

The Auto Off feature detects when the headset is not in use and shuts it off after

several minutes to preserve battery power. The exact time it takes to shut off

varies and can range between 3 to 9 minutes after you stop using the headset.

When the headset is running on battery power only and is not plugged in to an

intercom, it will shut off even when there is an auxiliary input present.

If you are on a phone call and unplugged from an intercom, the headset will

allow you to complete your call, then it will turn off approximately three seconds

after the call is terminated.

Note: To use the headset when unplugged from the intercom to listen to auxiliary

input audio or as a Bluetooth^®wireless technology-enabled headset to make or receive

calls, we recommend you disable the Auto Off feature for uninterrupted functionality.

Inserting and replacing the batteries

CAUTION: If the batteries do not fit correctly, do not force them in. Forcing an

improper connection will cause permanent damage to the control module.

To insert or replace the batteries

1. Turn off headset power.

2. Press down firmly on the battery compartment cover and slide the cover to

release. The battery door is tethered. Do not detach the door from module.

3. Insert the two supplied alkaline AA batteries into the control module,

observing proper polarity.

4. Replace the battery compartment cover.

Note: Replace batteries with alkaline batteries only. Do not use any other battery

chemistries.

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PREPARING THE HEADSET FOR USE

Connecting the headset to the aircraft

The Bose^®A20^®Aviation Headset can be configured to either plug into aircraft

power or rely entirely on battery power.

Using the 6-pin plug

A single 6-pin plug inserted into the 6-pin connector provides the headset with

aircraft power and intercom audio.

If your headset is aircraft-powered, a 6-pin connector must be installed and

mounted to an aircraft panel. See “Mounting the aircraft panel connector” on

page 31.

Note: An adapter is available from Bose to convert a 6-pin connector to a dual

G/A or U174 plug for additional connection flexibility.

To connect the headset

1. Align the 6-pin plug to the connector keyway by matching the narrow bar

on the plug to the slot on the connector.

2. Firmly press the plug into the connector jack.

Align keyway

Push plug in

To disconnect the headset

1. Pull back on the sleeve near the end of the 6-pin plug.

2. Gently continue pulling back to remove the plug from the connector.

CAUTION: Do not pull the connector out without first pulling back the sleeve.

Forcing the connector out will damage the cable and/or the aircraft instrument panel.

Pull sleeve back, then pull plug out

Sleeve

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PREPARING THE HEADSET FOR USE

English

Using the dual general aviation plugs

The most common battery powered (only) version of the headset has two

general aviation (G/A) plugs that connect to the aircraft audio. Although the

plugs look similar, the microphone plug is shorter, thinner, and has a slightly

different shape than the intercom plug.

Insert the thicker intercom plug in first. It will only fit into one of the jacks.

Then insert the thinner microphone plug into the other jack.

Microphone

Intercom/Audio

Using other plug types

The Bose^®A20^®Aviation Headset is also available with other types of plugs for

connecting to various aircraft audio jacks. These single-plug connectors should

be inserted into the appropriate jack on your aircraft control panel. Refer to

“Power and cable variations” on page 7.

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USING THE HEADSET

Wearing and adjusting the headset

Proper fit on your head is important both for comfort and optimal noise

reduction performance. Here are a few guidelines:

• Use the left (L) and right (R) markings above the earcups to orient the headset

properly.

• As you put the headset on, lightly grasp each earcup and adjust it so its

cushion is completely over your ear. You should feel an even, gentle pressure

all around each ear.

• Adjust the headband so it rests gently on top of your head.

Make your final adjustments with the headset powered on in a noisy

environment.

In very loud conditions, such as during takeoff, you may experience a brief

reduction in Acoustic Noise Cancelling^®as the headset compensates for a

momentary pressure change. If the problem continues when the sound level

returns to normal, see “In case of difficulty” on page 27. If the problem persists,

contact Bose^®Technical Support for assistance.

Conditions related to fit

A low rumbling sound or frequent, brief losses of Acoustic Noise Cancelling

noise reduction may indicate an improper fit or blocked earcup ports. See

“Headset earcup openings” on page 23 for instructions on removing

blockages.

During a long flight, you may feel a slight pressure point, which can be relieved

by adjusting the headband position. Your experience with using the headset will

help establish a sense of how it should sound and feel.

Microphone placement

Microphone placement is important for clear communications. With the

headset on your head, make these adjustments:

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USING THE HEADSET

English

1. Grasp the boom with your fingers and move the microphone up or down so

it is level with your mouth.

2. Pull the microphone in toward your lips. Position the microphone with its

talk side facing in. Though it will be slightly off center, the microphone

should be ¹

inch from the opening of your lips.

Mic label

Mic is too far

away

Mic label is

not facing

mouth

Mic is ¹

from mouth

inch

3. Make sure the talk side of the microphone is facing your lips. Do not purse

your lips.

Clothing clips

The control module cable is fitted with two clothing clips. Use the clips to

attach the headset cable to your clothing, a safety harness, or an aircraft door

pocket.

Press to open clip

Press to release and reposition

clip along the cable

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USING THE HEADSET

Using the control module

Use the control module to control the headset functions. There are two

variations of the module; one featuring Bluetooth^®wireless technology and one

that has basic functions only.

Bluetooth control module

Conventional control module

Left/Right volume controls*

Power indicator

Power button

Bluetooth

indicator

Bluetooth

function button

Bluetooth

Volume Up button

Multifunction

switch:

Audio Priority

switch:

Bluetooth

Volume Down button

Top

Intercom

prioritized

Top

Intercom

prioritized

Auxiliary (AUX)

audio input

Middle

Intercom

mixed

Middle

Intercom

mixed

Bottom

Intercom

only

Bottom

Intercom

only

*Control the intercom volume

Power button

Use the power button to turn Acoustic Noise Cancelling^®on or off, and control

indicator brightness.

• Press the power button once to turn on Acoustic Noise Cancelling noise

reduction.

• Press and hold the power button for 1-2 seconds to turn off Acoustic Noise

Cancelling noise reduction.

Note: Repeated pressing of the power button will not hasten the power off event.

If the unit does not power off, wait 3 seconds and press the power button again.

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USING THE HEADSET

English

• Double-click the power button to dim the power and Bluetooth^®wireless

technology indicators. To toggle the indicators between dim and bright,

rapidly press the power button twice.

Volume control

The left and right volume control wheels on the control module adjust the

volume of the corresponding earcup. With Acoustic Noise Cancelling^®off,

volume control will be set to the maximum level.

CAUTION: Avoid setting the volume levels too high. Exposure to loud sounds may

cause hearing damage.

Holding the control module upright and facing you:

• Use the left wheel to adjust volume of the left earcup.

• Use the right wheel to adjust volume of the right earcup.

Overall headset volume control requires adjustments at both the aircraft

intercom or radio and at the headset control module. Even at its lowest setting,

neither volume control wheel can completely turn off the volume.

Power indicator

New alkaline AA batteries will generally supply at least 45 hours of power for

the headset. Battery life varies with the ambient noise level of the aircraft,

temperature, ear cushion condition, use of the Bluetooth feature, and age of

the batteries. The power indicator changes color to indicate the power status,

as follows:

Indicator color Power source Type of light Indicates

Green

Amber

Aircraft

Battery

Slow flashing Power ON

Flashing

Power ON and batteries good

Fast flashing

Power ON, but batteries low

(8 hours or less remaining)

Red

Off

Battery

None

Faster flashing Power ON, but batteries very low*

(2 hours or less remaining)

None

Power OFF or batteries depleted

Note: Replace batteries with alkaline batteries only. Do not use any other battery

chemistries.

*Bluetooth wireless technology is disabled to conserve the remaining power once the battery

reaches this level.

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USING THE HEADSET

Auxiliary (AUX) audio input

The Bose^®A20^®Aviation Headset provides a ¹/8 inch (3.5 mm) AUX audio input

that allows you to use your headset with an external audio source such as a

portable GPS or a portable audio device. The connector is located at the

bottom end of the control module as shown.

AUX audio

input

Your headset includes a ¹/8 inch (3.5 mm) adapter cable to connect your

external audio device. Plug one end of the adapter cable into the headphone

plug on your device and the opposite end into the headset AUX audio input.

Note: None of the functions of a connected audio source are controlled by the

control module.

Note: This feature will not work unless the multifunction switch is turned on.

Note: When the headset is running on battery power only, and it is not plugged

into an intercom, it will shut off even when there is an auxiliary audio input signal

present. To use the headset when unplugged from the intercom to listen to

auxiliary input audio or as a Bluetooth^®wireless technology headset to make or

receive calls, we recommend you disable the Auto Off feature for uninterrupted

functionality.

Audio priority

The Bose A20 Aviation Headset allows you to decide the priority of the audio

sources you want to hear while using the headset. On the Bluetooth control

module, the audio priority is controlled by the multifunction switch. On the

conventional control module, the audio priority is controlled by the audio

priority switch.

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USING THE HEADSET

English

Multifunction/Audio priority switch

The multifunction/audio priority switch has three positions:

Position

Function

Operation

Top

Intercom prioritized When the switch is in the top position and an

over AUX intercom signal is detected, AUX audio is muted.

Middle

Intercom mixed with When the switch is in the middle position and an

AUX

intercom signal is detected, AUX audio is mixed

with the intercom audio.

Bottom

Intercom only

When the switch is in the bottom position, only

intercom audio is active.

Note: On the Bluetooth^®control module, when a Bluetooth wireless technology call

is present, the audio from the call mutes the signal on the AUX audio input. In either

the top or middle position of the multifunction switch, both the intercom and the

Bluetooth wireless technology signal are heard as mixed.

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USING THE HEADSET

Using the headset

with a Bluetooth^®-enabled phone

Pairing the headset with your phone

Pairing entails having the Bose A20^®Aviation Headset in pairing mode, setting

your Bluetooth-enabled phone to “discover” the headset, then confirming the

connection on the phone. Before you use your Bose^®A20 Aviation Headset

with your mobile phone, you must pair the two devices.

1. Turn on the headset and make sure the multifunction switch is in the top or

middle position, NOT in the emergency off position.

Power

Multifunction Switch

indicator light

Power button

Top position

Middle position

The power indicator light glows green or yellow, depending on the charge

level of the battery. If the light is red, the battery is low and needs replacing.

2. Press the Bluetoothfunction button (to activate Bluetooth.

If this is the first time you’ve activated or are attempting

to pair Bluetooth, the Bluetooth indicator will flash at a

slow rate alternating with the Power indicator. This

indicates that the headset is in “discoverable” mode

and ready to be paired to a cell phone.

Bluetooth

indicator

If the Bluetooth indicator does not flash alternately with the Power indicator

flash or you are trying to pair a headset that has previously been paired with

another phone, you will need to press and hold the Bluetooth function

button for 5 seconds in order to put the headset into “discoverable” mode.

3. With your Bluetooth-enabled phone turned on, locate the Bluetooth feature,

usually under Tools, Connect, or Bluetooth Devices. (Refer to the owner’s

instructions that came with your phone for further details.)

4. Set the phone to “discover” or “add” a Bluetooth device. When Bose A20

appears in the list of devices, select and confirm this choice.

5. If you are asked for a passkey or PIN, enter the digits 0000.

The control module Bluetooth and power indicators flash together to confirm

successful pairing.

If pairing is unsuccessful, repeat steps 3 - 5 above.

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USING THE HEADSET

English

Note: The Bose A20^®Aviation Headset will automatically exit pairing mode after

five minutes of inactivity.

Bluetooth^®indicator light status

The Bluetooth indicator is a blue light on the control module. It shows the status

of Bluetooth functions, as follows:

Appearance

Indication

Flashes slowly, alternating with the power indicator. Headset is discoverable or is pairing.

Flashes twice quickly with each power indicator

flash.

Bluetooth technology is ON but not

connected to a phone.

Flashes at the same rate with the power indicator

(green or amber).

Bluetooth technology is ON and

connected to phone.

Flashes once quickly with each power indicator flash. Headset is in an active phone call.

No light Bluetooth technology is not enabled.

Reconnecting to a previously connected phone

To reconnect the headset to a previously connected phone or other Bluetooth

wireless technology device, briefly press the Bluetooth function button on the

headset control module.

The headset control module attempts to connect with the last connected

Bluetooth wireless technology device.

Note: The Bose^®A20^®Aviation Headset can only be connected to one Bluetooth

wireless technology device at a time. If you press the Bluetooth function button on

the headset control module for more than five seconds, the currently connected

Bluetooth wireless technology device is disconnected and the control module

enters pairing mode.

Recovering a lost connection

When a connected Bluetooth wireless technology device moves out of range

and the connection is lost, the Bose A20 Aviation Headset automatically

attempts to reconnect. If a connection still does not exist after five minutes, the

Bluetooth wireless technology receiver in the control module remains on, but

not connected. The Bluetooth indicator on the Bose A20 Aviation Headset

control module will exhibit a fast double flash initiated at each power indicator

flash.

Disconnecting a Bluetooth technology-enabled phone

If you use a connected phone to end a Bluetooth wireless technology

connection, the Bluetooth technology receiver in the headset control module

remains on, but no longer attempts to connect. A Bluetooth wireless

technology connection is ended by turning the phone off, ending the current

call, or discontinuing the wireless connection.

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USING THE HEADSET

If you turn the headset control module off, the control module Bluetooth

wireless technology receiver also turns off, ending the connection to the

Bluetooth technology-enabled phone.

Bluetooth^®volume control

The Bluetooth volume control increases or decreases the volume of the mobile

phone that is paired to the Bose^®A20^®Aviation Headset. The Bluetooth volume

control is located on the right side of the control module. You can only adjust

the Bluetooth technology volume during an active phone call. To change the

volume, press the volume up or volume down button.

volume down

volume up

Each time you press a Bluetooth volume button, the volume increases or

decreases one level.

Note: Pressing and holding the volume button changes the volume continuously.

Note: When Bluetooth wireless technology is active, you cannot mute the sound

using the Bluetooth volume buttons.

To clear pairing device history from the headset

With Bluetooth technology enabled and on (Bluetooth indicator light flashing)

while not on a call, press and hold both Bluetooth volume up and Bluetooth

volume down buttons at the same time for 8 seconds. After 8 seconds, cycle

the Bluetooth power using the multifunction switch.

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USING THE HEADSET

English

Making and answering calls

To make a call

Dial from your mobile phone, and the call will automatically transfer to the

headset. If your phone has voice-activated dialing, press the Bluetooth^®

function button and wait for the phone voice prompts.

To activate voice dialing (if your phone provides this feature)

When there are no active or incoming calls, briefly press the Bluetooth function

button.

To answer a call

Briefly press the Bluetooth function button. You should hear a short beep in the

headphones before you hear the incoming call.

To end a call

Briefly press the Bluetooth function button. You should hear two short beeps in

the headphones to indicate that the call has been ended.

To reject an incoming call

Press the Bluetooth function button for three seconds.

Note: To avoid putting the control module into pairing mode, do not press the

Bluetooth function button for more than five seconds.

To redial the last number

When there are no active or incoming calls, press the Bluetooth function button

twice in quick succession.

Note: Whether or not you can reject an incoming call, activate voice dialing, or

redial the last number, depends on the capabilities of your phone. Please

check your phone user guide for further details.

To transfer the audio to the mobile phone

When you are on a call, press the Bluetooth function button for three to four

seconds. This transfers the audio to the mobile phone handset while the

Bluetooth wireless technology connection remains active.

Note: If you are on a call and unplugged from an intercom, the headset will allow

you to complete your call, then it will turn off approximately three seconds after the

call is terminated. To use the headset when unplugged from the intercom to listen

to auxiliary input audio, or as a standalone Bluetooth technology headset to make

or receive calls, we recommend you disable the Auto Off feature for uninterrupted

functionality.

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HEADSET CARE AND MAINTENANCE

Instructions for continued airworthiness

Bose recommends following the general care and maintenance instructions in

this guide. With normal use, items such as windscreens and ear cushions may

require periodic replacement. If cleaning or replacement of these items is

needed, follow the recommendations on the following pages. All other care and

maintenance, in and out of the warranty period, must be performed by Bose or

an authorized repair facility.

CAUTION: Do not immerse the headset in water or any other liquid. If the

headset is immersed in liquid, do not use it. Contact Bose^®Technical Support for

assistance.

Cleaning the headset

General cleaning

Gently wipe the outside surfaces of the headband, connectors, plastic parts,

and headband cushion, using a soft cloth moistened with water and mild soap.

Take special care when cleaning the ear cushions and the outside surfaces of

the earcups. Do not immerse ear cushions in water or any other liquid.

Headset earcup openings

The TriPort^®headset opening and the microphone opening must remain clean

and free of debris. Check to ensure that the openings on each earcup are clean

before each flight.

TriPort headset

opening

Microphone

opening

When wiping down the headset earcups, be sure not to force any dirt or debris

into the openings. Carefully use tweezers, if necessary, to remove foreign

matter that may be lodged in the openings. Do not blow air into or vacuum

the openings as this may damage the headset.

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HEADSET CARE AND MAINTENANCE

English

Microphone windscreen

Remove the windscreen from the microphone as described in “Microphone

windscreen replacement,” below.

Rinse and air dry the windscreen. Make sure the windscreen is completely dry,

then reattach.

Earcup inner screen

Do not attempt to remove, replace, repair, or clean this component. Located

inside the earcup, the inner screen is critical to proper headset operation. If the

screen appears to be damaged or worn out, contact Bose.

If the inner screen becomes damp from environmental moisture such as light

rain, dew, perspiration, or condensation, allow it to air dry only. Do not use

electric heaters, blowers, or hairdryer-type devices to dry the inner screen.

Headband cushion

1. Remove the cushion as described in “Headband cushion replacement” on

page 26.

2. Place the cushion in a solution of water and a mild detergent.

3. Allow the cushion to air dry, then reattach.

Replacing parts

Through normal use, parts like windscreens and ear cushions may require

periodic replacement. Replacement parts can be ordered directly from Bose

Corporation. Please refer to “Contact information” on page 37.

Microphone windscreen replacement

1. Roll the band that secures the windscreen off the tip of the microphone and

dispose of it.

2. Gently slide the windscreen off the microphone.

3. Slide the replacement windscreen on and make sure it fits completely over

the microphone.

4. Roll the new band onto the microphone tip, to about ¹

inch from the end of

the windscreen, to secure it.

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HEADSET CARE AND MAINTENANCE

Ear cushion replacement

As a general rule, ear cushions should be replaced every six months or every

350 hours of use, depending on how often you fly. You may have to replace

them more often, if you:

• Have a full beard or heavy whiskers.

• Subject the headsets to severe temperature extremes such as parking your

airplane outside in severe cold or heat.

• Put excess strain on the cushions because of improper storage.

Indications that the ear cushions need replacing include:

• Flaking of the outer covering.

• Cuts or tears.

• Flattening of the cushion, reducing the effectiveness of the seal.

To extend the life of the ear cushions, perform regular cleaning as described in

“General cleaning” on page 23.

Replacing the ear cushions

1. Grasp the ear cushion skirt where it folds into the slot on the earcup.

2. Gently pull the ear cushion skirt up and away from the earcup.

3. Properly align the replacement ear cushion with the earcup.

4. Tuck an edge of the ear cushion skirt into the slot behind the ear cushion

flange. Be careful not to fold the skirt over.

5. Gently stretch the cushion around the earcup, working the skirt into the slot

as you go.

6. Grasp the ear cushion and adjust its position to remove any folds in the

skirt and wrinkles in the cushion.

Battery replacement

Refer to “Inserting and replacing the batteries” on page 10.

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HEADSET CARE AND MAINTENANCE

English

Headband cushion replacement

The headband cushion is designed to give the maximum level of comfort to

your headset.

Bose recommends that you replace the cushion after regular care and

maintenance fails to restore the wool pile to its original size and shape.

To replace the cushion:

1. On a protected surface, turn the headset upside down. Remove the old

cushion from the headband.

2. While still holding the headband open, align the center of the new cushion

with the center of the headband and press firmly from the center toward

the outside.

Headband cushion

Microphone assembly or access cover replacement

Replace the microphone assembly or connector access cover as described in

“Attaching the microphone assembly” on page 8.

Storage

Store the headset in a ventilated area away from direct sunlight. Remove the

batteries before storing the headset for extended periods.

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TROUBLESHOOTING

In case of difficulty

Look for the problem in the left column of the table, then follow the “What to

do” instructions in the right column. If the problem persists, contact Bose using

the contact information on page 37 of this guide for assistance.

CAUTION: Do not attempt to disassemble or service the inside of the earcups or

other parts of the headset. Only the boom microphone cable, access cover, bat-

teries, windscreen, headband cushion, and ear cushions are replaceable by the

user. For instructions on how to care for and maintain the headset, see “Headset

Care and Maintenance” on page 23.

Noise Reduction

Problem

What to do

Communication,

but no Acoustic

Noise Cancelling^®

noise reduction in

either ear.

• Make sure the headset is turned on.

• Press the power button to turn the headset on.

• Check the power indicator. See page 16 for a description of the

power indicator.

• If using aircraft power, check the aircraft fuse or circuit breaker.

• If using battery power, make sure the batteries are fresh and

correctly installed.

Note: Replace batteries with alkaline batteries only. Do not use any

other battery chemistries.

No active Acoustic

Noise Cancelling

noise reduction and

no communication.

• Make sure the headphone plugs are securely inserted into the

panel connectors.

• Try using the headset in a different seat location.

• Remove the microphone assembly from the headset and check

for damage to the connector or pins. See “The microphone

assembly” on page 8.

Communications

Problem

What to do

Acoustic Noise

Cancelling noise

reduction, but no

incoming audio.

• Check to see if the volume controls are set too low. See “Volume

control” on page 16 for instructions on volume adjustment.

• Check the volume setting of intercom/radio.

• Make sure the headphone plugs are securely inserted into the panel

connectors.

• Try a different seat location in the aircraft.

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TROUBLESHOOTING

English

Problem

What to do

Low volume of

incoming

communications.

• Check to see if the volume controls are set too low.

Refer to “Volume control” on page 16 for instructions on

volume adjustment.

• Ensure that the stereo/mono switch is correctly set for your

intercom system.

• Check that all headsets sharing the intercom have the

stereo/mono switch in the correct position.

• Unplug all other headsets and see if the volume can be adjusted

to an acceptable level.

Intermittent

communication.

• Check that the connection to the aircraft panel is not loose.

• Try the headset in a different seat location.

Reduced volume in

one ear only.

• Check to see if the volume control is set too low.

Refer to “Volume control” on page 16 for instructions on

volume adjustment.

• Check the stereo/mono configuration switch.

Refer to “The operation switches” on page 9

No stereo

• If your aircraft has a mono audio system, verify that the

stereo/mono configuration switch is set to mono. Refer to “The

operation switches” on page 9. Depending on how your audio

jacks are wired, there may be only one channel of audio supplied

to the headphone jack. If the stereo/mono switch is set to stereo

and you only hear communications on one side, setting the

switch to mono plays audio on both sides.

separation or

communications in

one ear only.

Audio

Problem

What to do

Reduced Acoustic

Noise Cancelling^®

noise reduction,

intermittent clicking

sounds, or

communication

distortion in a loud

environment.

• Check the TriPort^®headset openings on the outside of each

earcup to ensure that they are not blocked. If dust or dirt is

present, carefully remove the debris using tweezers. Do not

vacuum or blow out debris.

• Make sure there are no air gaps around the ear cushion seals.

If ear cushions appear worn, they should be replaced. Refer to

“Ear cushion replacement” on page 25.

Squealing or

• Ensure the headset orientation is correct. Use the Left (L) and

Right (R) markings above the earcups to orient the

headset correctly.

• Inspect the seal between the ear cushion skirt and the earcup.

The skirt should fit into the slot on the earcup with no gaps.

Replace any cushions that appear to be worn out.

whistling sound

when the headset is

turned on.

• Adjust the earcup fit to create a better seal on your head.

The headset’s low-force design makes it sensitive to items that

interfere with the seal around your ear. Make sure your ears are

completely inside the ear cushions, and that a hat or eyeglasses

with thick temples do not interfere with the seal.

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TROUBLESHOOTING

Problem

What to do

Low rumbling

sound with the

headset turned on

in a quiet

• Adjust the earcup fit to create a better seal on your head. The

low-force design of the headset makes it sensitive to items that

interfere with the seal around your ear. Make sure your ears are

completely inside the ear cushions, and that a hat or eyeglasses

with thick temples do not interfere with the seal.

environment.

• Check ports at the outside surface of each earcup to ensure that

they are not blocked. If dust or dirt is present, carefully remove

the debris using tweezers. Do not blow out or vacuum debris.

• Inspect the seal between the ear cushion skirt and the earcup.

The skirt should fit into the slot on the earcup with no gaps.

Replace any cushions that appear to be worn out.

Crackling sound

audible with

• Ensure the headset orientation is correct. Use the Left (L) and

Right (R) markings above the earcups to orient the headset

correctly.

• Adjust the earcup fit. Refer to “Wearing and adjusting the head-

set” on page 13.

• If your headset is battery-powered, check to see if the battery is

low (indicated by fast blinking red LED).

• If your headset is aircraft powered, make sure the voltage

powering the headset is no less than 10 VDC.

headset turned on

in a loud

environment, or

Acoustic Noise

Cancelling^®noise

reduction is

intermittent.

• Inspect the seal between the ear cushion skirt and the earcup.

The skirt should fit into the slot on the earcup with no gaps.

Replace any cushions that have surface tears, torn stitching

joints, large wrinkles, or have become dried and stiff.

Auxiliary audio input

Problem

What to do

No audio from

auxiliary source.

• Turn source volume up.

• Try another source with the headset to eliminate the source as

the possible problem.

• Make sure multifunction switch is not set to the bottom (intercom

only) position. The multifunction switch must be either in the top

or middle position for audio from an auxiliary input to be enabled.

• Check the connection between the auxiliary source and the

control module. Both ends of the AUX IN connector cable must

be properly seated inside the sockets.

• If the multifunction switch is set to the prioritized position (top),

the auxiliary audio source will not be heard if there is an audio

signal from the intercom.

Audio in one ear

only from the

auxiliary input.

• Check the connection between the auxiliary source and the

module. Both ends of the AUX IN connector cable must be

properly seated inside the sockets.

• Make sure the earcup cover on the headset is in place and

properly connected. Refer to “Attaching the microphone

assembly” on page 8.

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TROUBLESHOOTING

English

Problem

Cannot hear

What to do

• Check headset prioritization settings. Refer to “Multifunction/

Audio priority switch” on page 18.

• Make sure all connections are secure (headset to intercom, AUX

input to headset).

• Communications audio is not present unless the headset is

connected to an intercom system.

communications

while listening to

audio from AUX

input or AUX input

does not mute with

incoming

communications.

Bluetooth^®wireless technology

Problem

What to do

No audio to the

headset while on a

call.

• Check to make sure the headset and phone are paired, the multi-

function switch is in the top or middle position, and the devices

are communicating with each other.

• Make sure the phone and headset are in range of the Bluetooth

wireless technology (no more than 30 feet from each other).

• Make sure the volume of the Bluetooth wireless technology is

turned up on the control module.

Note: On initial start-up, a 20-second delay may occur before audio

can be heard.

The headset is not

pairing with my

phone.

• Turn the headset off, then on again.

• Follow your phone instructions to remove all devices previously

paired with your phone.

• Repeat the steps for pairing the headset with your phone. Refer

to “Pairing the headset with your phone” on page 19.

Icannot answer/end

a call.

• Make sure your phone is properly paired and connected to the

headset. Refer to “Making and answering calls” on page 22.

The headset does

not reconnect to

my phone when I

turn it on.

• Make sure the phone has Bluetooth wireless technology enabled.

• Turn the multifunction switch on to the top or middle positions.

• Press the Bluetooth function button.

Auto off

Problem

What to do

Headset does not

shut off

automatically.

• In the battery compartment, make sure Switch #1 is set to ON

(default).

• Refer to “The operation switches” on page 9 for details on Auto

Off functionality.

• It may take up to nine (9) minutes for the headset to shut off

when not in use immediately after initial power up.

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English

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INSTALLATION

Mounting the aircraft panel connector

The aircraft panel connector is part of the optional 6-pin wiring harness

assembly.

Visit Bose.com or Global.Bose.com for information or purchase.

CAUTION: The aircraft panel connector must be mounted by a technician who is

qualified to perform this type of avionics installation for the aircraft you are using.

Mount the connector into a cutout, using the diagrams below as a guide.

12.5mm

.49"

AIRCRAFT INTERFACE SCHEMATIC

RED

1 V+IN

14.0mm

.55"

•

BLK

•

2 GND

BLK/WH

WHT

BLU

3 COMM L

4 COMM R

5 MIC HI

6 MIC LO

RECEPTACLE - PINOUT (FRONT VIEW)

WHT

Pin 6

WH/BLU

BLK/WH

Pin 1

Connect the eight wires as follows:

• Two for the microphone

• Two for audio

• One for power

• One for ground

• Two for audio shields

Audio and microphone wires should be connected to the back of the existing

microphone and headphone jacks, leaving existing jacks intact for use with

conventional headsets. This is usually the fastest installation method.

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INSTALLATION

English

CAUTION: Do not use excessive force or bend the installed connector. This may

damage or break internal solder joints.

Note: The aircraft panel connector cannot be installed in an audio system using

transformer-coupled audio outputs. Contact the Bose^®Technical Support, using

the contact information on page 37 of this guide for details.

Mono connection diagram

10-32

V DC

RED

BLK

WHT

BLU

WHT

1V+IN

2 GND

3 COMM L

4 COMM R

5 MIC HI

6 MIC LO

1/2A

BLK/WH

WHT/BLU

Ring

(audio)

Microphone - Jack

Existing PTT

switch

and wiring

TPP

(PTT)

Barrel

(gnd)

(no connection to

Bose headset)

Headphone - Jack

Existing wiring to

aircraft intercom/

audio panel

Tip

(phone audio)

Barrel

(audio gnd)

Stereo connection diagram

10-32

V DC

RED

BLK

1V+IN

1/2A

2 GND

BLK/WH

WHT

3 COMM L

4 COMM R

5 MIC HI

6 MIC LO

BLU

WHT

WHT/BLU

Audio

Microphone - Jack

Existing

PTT switch

and wiring

Barrel

(gnd)

TPP

(PTT)

(no connection to

Bose headset)

Phone

audio (right)

Stereo Headphone - Jack

Existing wiring to

aircraft stereo

intercom/audio panel

Barrel

(audio gnd)

Tip

(phone audio left)

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English

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INSTALLATION

Helicopter (U174) connection diagram

WHT/BLU

WHT

BLU

MIC LO

MIC HI

COMM R

COMM L

GND

WHT

BLK

RED

1/2A

10-32

V DC

V+IN

Existing single 4-

prong jack

Existing wiring to

helicopter intercom/

audio panel

Barrel

(audio gnd)

Note: Barrel ground (gnd) refers to aircraft grounds.

Details on making the connections

The pinouts for the optional installed connector are detailed in the table below:

Pin number Color

Purpose

Red

V+IN: Headset power (10-32 VDC). Use a ¹/4 amp fuse or

a ¹/2 amp circuit breaker.

Black

White

Blue

GND: System ground. Connect to the existing audio ground.

COMM L: Phone communication: Left.

COMM R: Phone communication: Right.

Note: For stereo operation, connect the left and right channels to their respective positions. For

monaural operation, connect pins 3 and 4 together, and to the tip of the existing phone jack.

White

MIC HI: Microphone/Hi-audio. Connect to the portion of the

existing microphone jack that corresponds to the ring

position of a headset microphone plug. Do not connect to

the tip (PTT) segment.

White/

Blue

MIC LO: Microphone/Lo-ground. Connect to the portion of

the microphone jack that corresponds to the barrel position

of a headset microphone plug.

Note: If the microphone works on radio transmit but not through the intercom, check pin 6. It

may be incorrectly wired to the PTT segment of the microphone jack.

Comm Shield

Mic Shield

Black

Shield from Comm L and Comm R wire pair.

Shield from Mic Hi and Mic Lo wire pair.

Note: The wires connecting pins 3 and 4 and pins 5 and 6 are shielded, twisted pairs with a

black wire shield termination exiting each pair. If the existing wiring is not shielded, connect the

shields to the existing audio wiring shields, or connect the shield from Comm L and Comm R

wire pair to audio ground.

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English

TECHNICAL INFORMATION

Damage could occur to avionics equipment that is

intended for use only with 600 Ohm headsets. If in doubt,

consult the avionics equipment manufacturer.

Headphone

Monaural mode: 160 Ohms ON and OFF

Stereo mode: 320 Ohms ON and OFF

Impedance

15 Hz to 15 kHz

Frequency response

Sensitivity: 92 dB SPL typical, measured at 1 mw,

1 kHz, full volume on a KEMAR ear simulator.

Bias required: 8 to 16 VDC through 220 to 2200 Ohms.

Microphone (Electret)

Sensitivity: Varies depending on bias and AC radio input

impedance. Typical output is 600 mV at 114 dB SPL. To

assure proper modulation of the radio, it is recommended

that an avionics technician adjusts its input to match the

output of the microphone.

Impedance: 5 Ohm or 150 Ohm dynamic mic

Sensitivity: Equivalent to M-87/M-101

Microphone (Dynamic)

115 dBC SPL for full active noise reduction performance

Maximum ambient noise level

Power source

Battery-powered: Two (2) AA alkaline

Aircraft-powered: 10 to 32 VDC

Battery-powered: Two (2) AA alkaline batteries

Aircraft-powered: 10 to 32 VDC

Voltage

Alkaline battery life: At least 45 hours in typical general

aviation aircraft noise. Duration varies with battery age,

ambient noise levels, temperature, ear cushion seal, and

use of the Bluetooth^®feature.

Battery life

Operating: 25 mA in typical aircraft noise

Current

amp, fast-blow fuse (AGC ¹/4 amp fuse) or ¹/2 amp

Fuse/breaker recommended

circuit breaker

12 ounces

Headset weight

Slider not extended:

Headset size range

8.425" (214mm) H x 6.34" (161mm) W x 3.15" (80mm) D

Slider extended:

10.2" (259mm) H x 6.6" (168mm) W x 3.15" (80mm) D

1.5" (38.1mm) H x 1.5" (38.1mm) W x 4.92" (125mm) D

Control module dimensions

Operating: 5 to 131°F (-15 to 55°C)

Storage: -67 to 158°F (-55 to 70°C)

Temperature and Altitude

(Category A)

Altitude: 15,000 feet maximum pressure altitude for

full cancellation

Hands-free profile, Bluetooth 2.1

Bluetoothwireless technology

Bluetooth technology QD ID

Bose^®A20^®Aviation Headset: B016487

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English

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TECHNICAL INFORMATION

FAA Technical Standards Order

The Bose^®A20^®Aviation Headset, its interface, cables, and microphones are

FAA approved to TSO C139. It has been designed to function in or withstand

exposure to the following environmental conditions:

Condition