Bose A20 ® ® Aviation Headset Owner’s Guide
Important Safety Information Please read this guide Please read this owner’s guide carefully. Save this guide for future reference and make it easily accessible for passengers and third parties who use the headset. Safety Warnings: • Turn the headset off if it emits any loud noise. As with any complex electronic device, it is possible for this headset to fail during operation.
Regulatory Information NOTE: This equipment has been tested and 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 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.
Regulatory Information Date of Manufacture: The eighth digit in the serial number indicates the year of manufacture; “8” is 2008 or 2018. China Importer: Bose Electronics (Shanghai) Company Limited, Part C, Plan 9, No. 353 North Riying Road, China (Shanghai) Pilot Free Trade Zone EU Importer: Bose Products B.V., Gorslaan 60, 1441 RG Purmerend, The Netherlands Taiwan Importer: Bose Taiwan Branch, 9F-A1, No.
Contents Introduction.......................................................................................... 7 About your Bose A20 Aviation Headset............................................................................7 Our commitment to you..........................................................................................................7 What’s included.........................................................................................................................7 Components....
Contents Recovering a lost connection................................................................................24 Disconnecting a Bluetooth device.......................................................................24 Clearing the headset pairing list..........................................................................24 Controlling Bluetooth volume..............................................................................24 Secondary audio modes..............................................
Introduction About your Bose® A20® Aviation Headset With the Bose® A20® Aviation Headset, you can rely on crisp, clear audio and significant noise reduction for all cockpit communications. You can also connect the headset to secondary audio sources such as smartphones or tablets. Our commitment to you We take great pride in designing each of our products with the goal of providing the highest performance possible in the price range of that product.
Introduction Components Headset Carrying case Clothing clip 2 AA alkaline batteries* Control module See “Control module variations” on page 9 for options 3.5 mm AUX audio 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 10. Warning: * Replace batteries with alkaline batteries only. Do not use any other battery chemistries.
Introduction Control module variations If you purchased the Bluetooth version of the headset, you received the Bluetooth control module. If not, you received the conventional control module.
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 6-pin* U174 5-pin XLR U384 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 flexib
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 you prefer, you can switch it to the right 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) where you want to attach the microphone assembly.
Preparing the Headset for Use The battery compartment The 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. Opening the battery compartment Press down firmly on the 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.
Preparing the Headset for Use This table shows possible positions, default setting, and purpose for each operation switch. Operation Switch PRIORITY (Available for Bluetooth® headsets only) INTERCOM (Available for headset configurations that support two-channel or stereo intercom systems only) AUTO ON (Available for aircraft powered headset versions only) AUTO OFF Purpose Establishes priority between two secondary audio sources. Select BT to give the Bluetooth (wireless) connection higher priority.
Preparing the Headset for Use Inserting and replacing the batteries Caution: If the batteries do not fit correctly, do not force them in. Forcing an 1. improper connection will cause permanent damage to the control module. 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 two alkaline AA batteries into the control module, observing proper polarity. 4.
Preparing the Headset for Use 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.
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. R L 160º • The microphone is intended to rotate no more than 160° as shown above. Do not force the microphone beyond the intended rotation.
Using the Headset Microphone placement Microphone placement is important for clear communications. With the headset on your head, make these adjustments: 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 (indicated by label). Though it will be slightly off center, the microphone should be 1/2 inch from the opening of your lips.
Using the Headset Using the control module If you purchased the Bluetooth® version of the headset, you received the Bluetooth control module. If not, you received the conventional control module.
Using the Headset 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.
Using the Headset Primary and secondary audio sources The aircraft intercom system (ICS) is always the headset’s primary audio source. When the headset is plugged in to the aircraft, intercom signals will always be heard and cannot be muted by the headset. In addition to the primary source (intercom), the headset can connect to secondary audio sources. Secondary sources can be either AUX (wired) or Bluetooth® (wireless). Note: Only one secondary source can be heard at a time.
Using the Headset Using the headset with a Bluetooth® device Pairing the first device 1. Press to turn on the headset. 2. Make sure the Secondary Audio Mode selector is in the MUTE or MIX position (not OFF). MUTE MIX The power indicator glows green or yellow, depending on the charge level of the battery. (If the light is red, the battery is low and needs replacing.) The Bluetooth indicator flashes purple to indicate that the headset is in pairing mode.
Using the Headset Pairing another device The headset can pair with up to eight devices. To pair another device: 1. Press and hold for one second to put the headset into pairing mode. The Bluetooth indicator flashes purple. ® Bluetooth indicator Bluetooth multi-function button 2. Locate the Bluetooth menu on your device and make sure the Bluetooth feature is ON. 3. Select Bose A20 from the Bluetooth device list. The Bluetooth indicator flashes blue while the devices are pairing.
Using the Headset Making and answering calls Call activity What to do To make a call Dial from your connected phone. The call will automatically transfer to the headset. To activate voice control (if available) When there are no active or incoming calls, briefly press To answer a call To end a call To ignore an incoming call To redial the last number To transfer the audio to the mobile phone . Briefly press . You should hear a short beep in the headset before you hear the incoming call.
Using the Headset Reconnecting to a previously connected device Each time you turn on the Bluetooth feature, the headset will attempt to r econnect with the two most recently connected Bluetooth® devices. 1. Turn the headset on. 2. Make sure the Bluetooth indicator is flashing blue. If not, press The indicator flashes blue. 3. To confirm connection, check the Bluetooth device list on your device. .
Using the Headset Secondary audio modes If you have connected one or more secondary audio sources to the headset, you must decide how you want to hear those secondary sources. o select how you will hear your secondary audio sources, use the Secondary T Audio Mode selector on the control module. Secondary Audio Mode selector The selector has three positions: MUTE, MIX and OFF.
Using the Headset Managing multiple secondary sources The headset can connect one AUX (wired) source and up to two Bluetooth® (wireless) sources at a time. If you are likely to receive important information from a particular secondary source (such as a GPS or a warning system), you can assign priority to that source. This insures that incoming audio from the priority source will always override other source. Setting the Priority (BT-AUX) switch To assign priority to one of your secondary sources: 1.
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 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.
Headset Care and Maintenance 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.
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.
Headset Care and Maintenance 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.
Troubleshooting 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 42 of this guide for assistance. Warning: 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, batteries, windscreen, headband cushion, and ear cushions are replaceable by the user.
Troubleshooting Problem What to do Low volume of incoming communications • On the control module, make sure the volume controls are not set too low. See “Intercom volume controls” on page 19. • On the intercom/radio, make sure the volume controls are not set too low. • Inside the battery compartment, make sure the Intercom (MON-ST) switch is correctly set for your intercom system. See “The operation switches” on page 12-12.
Troubleshooting Problem What to do Squealing or whistling sound when the headset is turned on • Make sure 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. • Adjust the earcup fit to create a better seal on your head.
Troubleshooting AUX audio source Problem What to do No audio from AUX source • On the AUX source, turn the volume up. • Make sure the 3.5 mm AUX audio cable is firmly connected to the control module and the AUX source. • On the control module, make sure the Secondary Audio Mode selector is in the MUTE or MIX position. • If the Secondary Audio Mode selector is set to MUTE, all secondary audio sources are temporarily muted when an intercom signal is detected.
Troubleshooting Bluetooth® audio source Problem What to do No audio from the Bluetooth source to the headset while on a call • On the control module, make sure the Secondary Audio Mode selector is in the MUTE or MIX position. • On the control module, make sure the Bluetooth feature is on, and once. the Bluetooth indicator is flashing. If not, press • Make sure the phone and headset are in range (no more than 30 feet from each other). • On the control module, make sure the Bluetooth volume is turned up.
Installation Mounting the aircraft panel connector The aircraft panel connector is part of the optional 6-pin wiring harness assembly. Visit www.Bose.com or www.global.Bose.com for information or purchase. Warning: 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. Receptacle - Pinout (front view) 12.5mm .49" Pin 6 14.0mm .
Technical Information 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 Bose Technical Support, using the contact information on page 39 for details.
Technical Information Helicopter (U174) connection diagram WHT/BLU 6 MIC LO WHT 5 MIC HI BLU 4 COMM R WHT 3 COMM L BLK 2 GND 10-32 RED 1 V+IN V DC 1/2A Existing single 4prong jack Existing wiring to helicopter intercom/ audio panel Barrel (audio gnd) Tip (MIC HI) 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 1 Red V+IN: Headset power (10-32 VDC).
Technical Information Headphone Damage could occur to avionics equipment that is intended for use only with 600 Ohm headsets. If in doubt, consult the avionics equipment manufacturer. Impedance Monaural mode: 160 Ohms ON and OF Stereo mode: 320 Ohms ON and OFF Frequency response 15 Hz to 15 kHz Sensitivity: 92 dB SPL typical, measured at 1 mw, 1 kHz, full volume on a KEMAR ear simulator. Microphone (Electret) Bias required: 8 to 16 VDC through 220 to 2200 Ohms.
Technical Information FAA Technical Standards Order The Bose® A20® Aviation Headset that are approved to TSO and ETSO C139 are appropriately marked.
Service and Warranty Information Locating the headset serial number Your Bose® A20® Aviation Headset is identified by a unique headset serial number located on the underside of the headband and underneath the headband cushion. Reference this serial number when you register your product or contact Bose for technical support. Be sure to properly reseat the headband cushion by pressing down firmly. For more information on replacing the headband cushion, see Refer to “Headband cushion replacement” on page 30.
Service and Warranty Information Contact information Contact Bose for: • Spare parts and accessories • Technical advice • Installation information • Warranty and repair information In North America: Bose Technical Support 145 Pennsylvania Avenue Framingham, MA 01701-9168 USA TEL: 1-800-233-4416 (US); 508-879-7330, ext. 62006 (outside U.S.) FAX: 1-508-766-5997 E-MAIL: aviationheadsetsupport@Bose.
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