GMA342 Audio Panels Coming April

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Product Information

Specifications

• Product Name: GMA 342/345
• Installation Manual: 190-01878-02
• Revision: 6
• Manufacturer: Garmin International, Inc.
• Technical Support Line: 1.888.606.5482
• Website: www.flygarmin.com

Product Usage Instructions

Section 1: General Description

The GMA 342/345 is an aviation panel-mount device designed to
provide audio inputs/outputs, mic keys, marker beacon
functionality, and more.

Section 2: Installation Overview

The installation process involves understanding the equipment
description, music function, and following the installation
procedure outlined in the manual.

Section 3: Installation Procedure

Follow the step-by-step instructions provided in Section 3 to
correctly install the GMA 342/345 unit in your aircraft.

Section 4: System Interconnects

This section covers audio inputs/outputs, mic keys, discrete
inputs, and marker beacon interconnectivity for the GMA
342/345.

FAQ (Frequently Asked Questions)

Q: Is the GMA 345 compatible with the 3-COM version unit?

A: Yes, unless otherwise noted, information listed for the GMA
345 also applies to the GMA 345 3-COM version unit.

Q: What should I do if I have questions about chemicals present

in the product?

A: For questions regarding chemicals known to cause harm, please
refer to Garmin’s website at www.garmin.com/prop65 for more
information.

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GMA 342/345
Installation Manual

190-01878-02

July, 2023

Revision 6

© 2023 Garmin Ltd. or its subsidiaries
All Rights Reserved
Except as expressly provided herein, no part of this manual may be reproduced, copied, transmitted, disseminated, downloaded or stored in any storage medium, for any purpose without the express prior written consent of Garmin. Garmin hereby grants permission to download a single copy of this manual and of any revision to this manual onto a hard drive or other electronic storage medium to be viewed and to print one copy of this manual or of any revision hereto, provided that such electronic or printed copy of this manual or revision must contain the complete text of this copyright notice and provided further that any unauthorized commercial distribution of this manual or any revision hereto is strictly prohibited.
©2017 The Bluetooth® word mark and logos are registered trademarks owned by Bluetooth SIG, Inc. and any use of such marks by Garmin is under license. Other trademarks and trade names are those of their respective owners.
Garmin International, Inc. 1200 E. 151st Street
Olathe, KS 66062 USA Aviation Panel-Mount Technical Support Line (Toll Free) 1.888.606.5482
Garmin (Europe) Ltd. Liberty House, Hounsdown Business Park Southampton, Hampshire SO40 9LR U.K.
Garmin Würzburg GmbH Beethovenstrasse 1a
97080 Würzburg, Germany
Garmin aviation support and warranty information can be found at www.flygarmin.com.

RECORD OF REVISIONS

Revision 2 3 4 5 6

Revision Date 09/18/17 04/05/18 09/17/19 11/25/20 07/05/23

Description Updated Transmitter Grant of Equipment Authorization info Updated Post Installation Checkout Procedure, added 3-COM unit info Added missing pin info to Table 4-2 Added RS-232 pin info Added new unit part numbers

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GMA 342/345 Installation Manual Page A

Revision 6

CURRENT REVISION DESCRIPTION

Page Number
A 1-1 1-5 1-8 1-9, 1-10 2-1 A-1 C-2, C-9

Section Number
Front 1.2 1.3.2 1.4.2 1.4.3 2.2.1 A.2 Appdx C

Description of Change
Added Garmin Germany address Updated Equipment Description info Updated Music Function info in Table 1-3 Added Table 1-10 and updated Table 1-11 Updated Transmitter Grant of Equipment Authorization info Updated Catalog of Part Numbers Table 2-1 Added reference to Table 2-1 Updated Figure C-2 and Figure C-9

INFORMATION SUBJECT TO EXPORT CONTROL LAWS
This document may contain information which is subject to the Export Administration Regulations (“EAR”) issued by the United States Department of Commerce (15 CFR, Chapter VII, Subchapter C) and which may not be exported, released, or disclosed to foreign nationals inside or outside of the United States without first obtaining an export license. The preceding statement is required to be included on any and all reproductions in whole or in part of this manual.

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DEFINITIONS OF WARNINGS, CAUTIONS, AND NOTES

WARNING This product, its packaging, and its components contain chemicals known to the State of California to cause cancer, birth defects, or reproductive harm. This Notice is being provided in accordance with California’s Proposition 65. If you have any questions or would like additional information, please refer to our web site at www.garmin.com/prop65.
NOTE Unless otherwise noted, information listed for the GMA 345 also applies to the GMA 345 3-COM version unit.
SOFTWARE LICENSE AGREEMENT
BY USING THE DEVICE, COMPONENT OR SYSTEM MANUFACTURED OR SOLD BY GARMIN (“THE GARMIN PRODUCT”), YOU AGREE TO BE BOUND BY THE TERMS AND CONDITIONS OF THE FOLLOWING SOFTWARE LICENSE AGREEMENT. PLEASE READ THIS AGREEMENT CAREFULLY. Garmin Ltd. and its subsidiaries (“Garmin”) grants you a limited license to use the software embedded in the Garmin Product (the “Software”) in binary executable form in the normal operation of the Garmin Product. Title, ownership rights, and intellectual property rights in and to the Software remain with Garmin and/or its third-party providers. You acknowledge that the Software is the property of Garmin and/or its third-party providers and is protected under the United States of America copyright laws and international copyright treaties. You further acknowledge that the structure, organization, and code of the Software are valuable trade secrets of Garmin and/or its third-party providers and that the Software in source code form remains a valuable trade secret of Garmin and/or its third-party providers. You agree not to reproduce, decompile, disassemble, modify, reverse assemble, reverse engineer, or reduce to human readable form the Software or any part thereof or create any derivative works based on the Software. You agree not to export or re-export the Software to any country in violation of the export control laws of the United States of America.

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TABLE OF CONTENTS

PARAGRAPH

PAGE

Section 1 General Description …………………………………………………………………1-1
1.1 Introduction………………………………………………………………………………………………………. 1-1 1.2 Equipment Description ………………………………………………………………………………………. 1-1 1.3 Technical Specifications …………………………………………………………………………………….. 1-3 1.4 Certification ……………………………………………………………………………………………………… 1-7 1.5 Operating Instructions………………………………………………………………………………………. 1-10 1.6 Reference Documents ………………………………………………………………………………………. 1-10

Section 2 Installation Overview ……………………………………………………………….2-1
2.1 Introduction………………………………………………………………………………………………………. 2-1 2.2 Installation Materials …………………………………………………………………………………………. 2-1 2.3 Available Accessories………………………………………………………………………………………… 2-2 2.4 Installation Considerations …………………………………………………………………………………. 2-4 2.5 Cabling and Wiring……………………………………………………………………………………………. 2-7 2.6 Electrical Bonding …………………………………………………………………………………………….. 2-7 2.7 Cooling Air ………………………………………………………………………………………………………. 2-8 2.8 Configuration, and Adjustment Options ……………………………………………………………….. 2-8 2.9 Updating Software …………………………………………………………………………………………… 2-13 2.10 Electrical Noise……………………………………………………………………………………………… 2-14 2.11 Mounting Requirements …………………………………………………………………………………. 2-15

Section 3 Installation Procedure………………………………………………………………3-1
3.1 Unpacking Unit…………………………………………………………………………………………………. 3-1 3.2 Electrical Connections ……………………………………………………………………………………….. 3-1 3.3 Antenna Installation …………………………………………………………………………………………… 3-2 3.4 Shield Block Backshell Installation Instructions ……………………………………………………. 3-2 3.5 Backshell Assembly…………………………………………………………………………………………… 3-3 3.6 Unit Installation ………………………………………………………………………………………………… 3-3 3.7 Post Installation Checkout …………………………………………………………………………………. 3-4 3.8 Continued Airworthiness ……………………………………………………………………………………. 3-7 3.9 Diagnostics Information …………………………………………………………………………………….. 3-7 3.10 Disabling Bluetooth Connectivity (GMA 345 only) …………………………………………….. 3-8

Section 4 System Interconnects ……………………………………………………………….4-1
4.1 Connector Description ……………………………………………………………………………………….. 4-1 4.2 Pin List …………………………………………………………………………………………………………….. 4-1 4.3 Aircraft Power…………………………………………………………………………………………………… 4-4 4.4 Lighting Bus …………………………………………………………………………………………………….. 4-5 4.5 RS-232 …………………………………………………………………………………………………………….. 4-5

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PARAGRAPH

PAGE

4.6 Audio Inputs/Outputs and Mic Keys ……………………………………………………………………. 4-5 4.7 Discrete Inputs ………………………………………………………………………………………………… 4-12 4.8 Marker Beacon………………………………………………………………………………………………… 4-12

Appendix A Installation Considerations for Upgrading from a Garmin GMA 340 ………………………………………………………………A-1
A.1 Mechanical Considerations ……………………………………………………………………………….. A-1 A.2 Electrical Considerations ………………………………………………………………………………….. A-1 A.3 GMA 340 to GMA 342/345 Retrofit Connections ……………………………………………….. A-2

Appendix B Outline and Installation Drawings ………………………………………B-1

Appendix C Interconnect Drawings………………………………………………………..C-1

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1 GENERAL DESCRIPTION
1.1 Introduction
This manual is intended to provide mechanical and electrical information for use in the planning and design of an installation of the GMA 342/345 into an aircraft. This manual is not a substitute for an approved airframe-specific maintenance manual, installation design drawing, or complete installation data package. Attempting to install equipment by reference to this manual alone and without first planning or designing an installation specific to your aircraft may compromise your safety and is not recommended. The content of this manual assumes use by competent and qualified avionics engineering personnel and/or avionics installation specialists using standard aviation maintenance practices in accordance with Title 14 of the Code of Federal Regulations and other relevant accepted practices. This manual is not intended for use by individuals who do not possess the competencies and abilities set forth above.

NOTE Garmin recommends installation of the GMA 342/345 by a Garmin-authorized installer. To the extent allowable by law, Garmin will not be liable for damages resulting from improper or negligent installation of the GMA 342/345. For questions, please contact Garmin Aviation Product Support at 1-888-606-5482.
1.2 Equipment Description
The Garmin GMA 342/345 Audio Panels are TSO-certified products and have received FAA approval.
The GMA 342/345 units are high-fidelity digital audio panels that collect, process, and distribute audio signals to crew and passengers. The GMA 342/345 digital signal processing (DSP) core filters the audio signals and provides digital audio routing to minimize noise.
The GMA 342/345 provides a speaker output for use as a cockpit speaker. Both also include a cockpit voice recorder and playback feature to help in situations where a COM transmission may need to be heard again. The GMA 345 includes a Bluetooth® transceiver for listening to music and making phone calls, or sending headset audio to a VIRB XE, and a 10 Watt USB charge port for phones and tablets. The GMA 342 does not have Bluetooth capability and includes an available front panel 3.5 mm jack for plugging in phones or tablets for music audio or cell phone calls.
Other features include intuitive configuration, a lighting bus input, SD Card socket for code loads and Bluetooth firmware updates (only GMA 345 has Bluetooth capability), an 8 position DIP switch for installation settings, and multiple audio switching functions. LED-illuminated push-buttons allow audio selection and annunciation for selection of NAV, COM, and other audio. Photocell dimming circuitry automatically adjusts the brightness of the annunciators, with backlighting controlled by the aircraft lighting bus. A fail-safe circuit connects the pilot’s headset and microphone directly to COM 1 and a failsafe warning audio input in the event that power is interrupted or the unit is turned off.
The GMA 345 has 2 music inputs in addition to the Bluetooth transceiver, NAV, COM, and ICS selections. The GMA 342 has 2 music inputs in addition to the front panel 3.5 mm jack, NAV, COM, and ICS selections. Both the GMA 345 and GMA 342 are easily configurable without an external PC connection. Both GMA 345 and GMA 342 have automatic intercom squelch and optional keyed intercom squelch. These audio panels were designed to be drop in replacements for the GMA 340, and do not interface or integrate to any system. The standard (2-COM) version of these audio panels only support two COMs, however a 3-COM version of the GMA 345 (see catalog part number Table 2-1) is also available. For installations that require more than 2 COMs the recommended audio panel is the GMA 345 3-COM, GMA 350H, or GMA 350Hc.

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1.2.1

NOTE Unless otherwise noted, information listed for the GMA 345 also applies to the GMA 345 3-COM version unit.
Features Summary

Table 1-1 GMA 342/345 Features Summary

Feature

GMA 342

GMA 345

GMA 345 3-COM

Bluetooth Transceiver

None

1 – Not shared with Music 1 or Music 2

USB Charge Port

None

1

3.5 mm 4-Conductor Jack Input

1 – not shared with Music 1 or Music 2

None

Tranceiver Channels

3 – COM 1, COM 2, TEL

4 – COM 1, COM 2, COM 3, TEL

Receiver Inputs

5 – NAV 1, NAV 2, AUX 1, AUX 2, AUX 3*

5 – NAV 1, NAV 2, AUX 1, AUX 2, AUX 3 **

Microphone Inputs

6 – Pilot, Copilot, 4 Passenger

Microphone Keys

2 – Pilot, Copilot

Music Inputs (rear connector)

2

Alert Inputs (unswitched)

4

Speaker Output

1

Headset Outputs

3 – Pilot, Copilot, Passenger (passenger output can drive 4 headsets)

Discrete Inputs

5

Discrete Outputs

3

Failsafe Channel

1 – Only Heard During Power Off Mode

Lighting Bus

1

SD Card Socket

1

8 Position DIP Switch

1

*Note that two buttons (AUX1 and AUX 2) are used to select/deselect the 3 AUX inputs. Pressing the AUX 1 button selects/deselects the AUX 1 and AUX 3 receivers. Pressing the AUX2 button selects/ deselects the AUX 2 receiver.
**Note that one button (AUX) is used to select/deselect all 3 AUX inputs. When AUX is selected, audio from all three AUX inputs is merged and heard together.

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1.3 Technical Specifications It is the responsibility of the installing agency to obtain the latest revision of the GMA 34X Environmental Qualification Form. This form is available directly from Garmin under the following part number: GMA 34X Environmental Qualification Form, Garmin part number 005-00880-01 To obtain a copy of this form, see the dealer/OEM portion of the Garmin web site (www.garmin.com). 1.3.1 Physical Characteristics

Table 1-2 Physical Characteristics GMA 342/345

Characteristic Bezel Height Bezel Width Rack Height (Dimple to Dimple) Rack Width Depth Behind Panel with Connectors (measured from face of aircraft panel to rear of connector backshells) GMA 342/345 Weight (Unit Only) GMA 342/345 Weight (Installed with rack, backplate, and connectors)

Specification 1.30 inches (33.0 mm) 6.30 inches (160.0 mm) 1.33 inches (34.0 mm) 6.30 inches (160.0 mm)
8.09 inches (205.0 mm)
1.10 lbs (0.49 kg) 1.78 lbs (0.81 kg)

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1.3.2 Electrical Specifications Table 1-3 Electrical Characteristics

Characteristic Environmental Compliance Software Compliance Maximum Absolute Audio Delay Altitude Maximum Days of Continuous Operation
Audio Panel Functions
Intercom Functions
Headphone Outputs

RTCA DO-160F

Specification

RTCA DO-178B Level D
The Input to Output delay is less than 1.1 ms for all audio I/O excluding entertainment audio (Music, Telephone, and Bluetooth)
55,000 Feet Overpressure – 15,000 Feet

49

Dedicated Transceiver inputs: 3 (including TEL) for GMA 342 and 345, 4 (including TEL) for GMA 345 3-COM unit Dedicated Receiver inputs: 5 (per notes in Table 1-1 regarding which AUX inputs are uniquely selectable) Alert (unswitched) inputs: 4 (each with configurable volume) Input impedance: 600 Input isolation: 60 dB minimum Alert/Receiver/Transceiver bandwidth: 100 Hz to 6.5 kHz Special functions: Fail-safe operation All inputs use MASQTM processing (Master Avionics Squelch) Max input 5 Vrms
Positions: 6 – Pilot, Copilot, 4 Passengers Volume controls: 4 (Pilot ICS, Pilot Music, Copilot/Passenger ICS, Copilot/Passenger Music) Microphone input impedance: 150 (compatible with 150 to 600 mics) Microphone bias voltage: 11 Vdc delivered through 470 Intercom isolation modes: 3 – Pilot, Crew, and All Telephone interfaces: 1 full-duplex (use rear LRU pins or Bluetooth transceiver) ICS Auto-Squelch/VOX: Independent DSP (digital signal processing) determined thresholds for each mic. Note that keyed intercom is optional. Auto-squelch not available when using keyed ICS.
Output amplifiers: 3 Stereo – Pilot, Copilot, Passengers Power, Load, and Distortion: 65 mW into 150 Ohms with <10% THD+N @ 10% output <3% THD+N Typical Operating Distortion: <1% THD+N 3dB Frequency Response Bandwidth: 20 Hz to 20 kHz for Music 350 Hz to 6.5 kHz for Other Audio (MICs, Radios, Alerts)

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Characteristic
Music Functions
Bluetooth Connectivity GMA 345 only
USB Charge Port GMA 345 only
3.5 mm Front Panel Jack GMA 342 only
Marker Beacon Receiver

Table 1-3 Electrical Characteristics
Specification
Music inputs (stereo): 2
Music input impedance: 600 (differential)
Music gain: +24dB @ max. volume
Music input level:<200 mVrms for full power output @ max music volume knob position (typ.)
3.0 Vrms max music input level
Music bandwidth: 20 Hz to 20 kHz @ full power output
Music distortion: <0.1% THD+N (typ.) @ full power, full bandwidth
Full power output refers to 65 mW into 150 at the headset
Bluetooth 3.00 Compliant (011-03520-00 and 011-03520-20). Bluetooth 5.00 Compliant (011-03520-01 and 011-03520-21).
Allows music, cell phone calls, and interface with the VIRB XE action camera. Bluetooth capability supports HFP (including HFP v1.6 Wide Band Speech mode), A2DP, and AVRCP.
The GMA 345 stores 10 paired devices and overwrites the least recently connected device when a new device is paired. Only 1 Bluetooth connection allowed at one time. The VIRB XE cannot be connected when using a phone (and vice versa).
USB charge port – Rated for 10 W. The GMA 345 charge port features USB port detection that will connect the optimum charge rate for the device connected. The charge port supports a maximum of 2.1 Amp charge current for devices. The USB charge port will shutdown and protect the GMA 345 for current draw above 2.3 Amps.
The GMA 342 has a standard 3.5 mm front panel jack for connecting by cable phones or tablets. The front panel allows stereo music to be played from a device, and also allows cell phone calls to be made through the GMA 342. The front panel jack is a 4 conductor jack, allowing either a standard 3 conductor plug for audio, and also 4 conductor plugs used by some cell phones for phone calls.
For stereo music input, the jack is rated to 1.5 Vrms and has 5 kohm input impedance.
Frequency: Crystal controlled at 75 MHz Sensitivity: LO 1000 V hard; HI 200 V hard Selectivity: 6 dB @ ±10 kHz min, 40 dB @ ±200 kHz max. Input impedance: 50 External lamp drive: 125 mA max each output Other outputs: Middle MKR sense Special functions: SmartMuteTM marker audio muting

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Aircraft Voltage 14V 28V

Table 1-4 Speaker Output Speaker Impedance 4 8 4 8

Output Power 3 Watts
Not Recommended 10 Watts 7 Watts

1.3.3 Power Requirements The GMA 342/345 will operate down to emergency voltage (9 Volts). Below 11 Volts, the USB charge port (GMA 345 only) and the speaker (both GMA 342 and GMA 345) are disabled.
Table 1-5 GMA 342/345 Power Requirements

Characteristic

Specification

Input Voltage Range

11 to 33 Vdc

Leakage Current*

< 1 mA

*Current the unit draws when turned off (GMA 342/345 turned off by the knob).

Table 1-6 GMA 342 Power Requirements

Characteristic

Current Draw

Idle Current*

0.34 A @ 14 VDC 0.19 A @ 28 VDC

Typical Operating Current

0.83 A @ 14 VDC 0.43 A @ 28 VDC

Maximum Current

1.19 A @ 14 VDC 0.90 A @ 28 VDC

*Unit current drawn with power applied, no audio, and minimum lighting.

Power Consumption
4.76 W @ 14 VDC 5.32 W @ 28 VDC
11.62 W @ 14 VDC 12.04 W @ 28 VDC
16.66 W @ 14 VDC 25.20 W @ 28 VDC

Table 1-7 GMA 345 Power Requirements

Characteristic

Current Draw

Idle Current*

0.34 A @ 14 VDC 0.19 A @ 28 VDC

Typical Operating Current without USB charge port being used.

0.83 A @ 14 VDC 0.43 A @ 28 VDC

Maximum Current with no USB charge port connection

1.19 A @ 14 VDC 0.90 A @ 28 VDC

Maximum Current with USB charge port connection

2.39 A @ 14 VDC 1.49 A @ 28 VDC

*Unit current drawn with power applied, no audio, and minimum lighting.

Power Consumption 4.76 W @ 14 VDC 5.32 W @ 28 VDC
11.62 W @ 14 VDC 12.04 W @ 28 VDC
16.66 W @ 14 VDC 25.20 W @ 28 VDC
33.46 W @ 14 VDC 41.72 W @ 28 VDC

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1.4 Certification
The conditions and tests required for TSO approval of this article are minimum performance standards. It is the responsibility of those installing this article either on or within a specific type or class of aircraft to determine that the aircraft installation conditions are within the TSO standards. TSO articles must have separate approval for installation in an aircraft. The article may be installed only if performed under 14 CFR part 43 or the applicable airworthiness requirements. The GMA 345 and GMA 342 have been shown to meet compliance with the claimed TSO(s) when interfaced with the equipment defined in this installation manual, and installed in accordance with the requirements and limitations as defined in this installation manual.
The Appliance Project Identifier (API) for the GMA 342 and GMA 345 is GMN-01319. The API has been used for project identification with the FAA. See applicable hardware and software part numbers to identify appliance approvals.
1.4.1 TSO Compliance
Table 1-8 GMA 342/345 (011-03520-00 and 011-03520-10) TSO Compliance

Function

TSO/ETSO/ RTCA/EUROCAE

Category

Airborne Radio Marker Receiving Equipment
Aircraft Audio Systems and Equipment

TSO-C35d DO-143
TSO-C139a DO-214A

A Class Ib

Applicable LRU Software Part
Numbers
All 006-B2227-0( )

Applicable LRU Boot Block Part
Numbers
All 006-B2227-B( )

Table 1-9 GMA 345 (011-03520-20) TSO Compliance

Function

TSO/ETSO/ RTCA/EUROCAE

Category

Airborne Radio Marker Receiving Equipment

TSO-C35d DO-143

A

Aircraft Audio Systems and Equipment

TSO-C139a DO-214A

Class Ib

Applicable LRU Software Part
Numbers
All 006-B2227-0( )
except 006-B2227-00
and 006-B2227-01

Applicable LRU Boot Block Part
Numbers
All 006-B2227-B( )

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1.4.2 TSO Deviations

Table 1-10 GMA 342/345 (011-03520-01, 011-03520-11, and 011-03520-21) TSO Compliance

Function

TSO/ETSO/ RTCA/EUROCAE

Category

Airborne Radio Marker Receiving Equipment

TSO-C35d DO-143

A

Aircraft Audio Systems and Equipment

TSO-C139a DO-214A

Class 1b

Applicable LRU Software Part
Numbers
All 006-B2227-0()
except 006-B2227-00
and 006-B2227-01
and 006-B2227-02

Applicable LRU Boot Block Part
Numbers
All 006-B2227-B( )
except 006-B2227-BA

Table 1-11 GMA 342/345 (011-03520-00/-01, 011-03520-10/-11, and 011-03520-20/-21) TSO Deviations

TSO TSO-C35d

Deviation
Garmin received a deviation from TSO-C35d to not permanently and legibly marking the unit with each TSO’s required information.
Garmin received a deviation from TSO-C35d to use FAR §45.15(b) instead of FAR §37.7(d) as the general rules governing holders of the TSO authorizations.
Garmin received a deviation from TSO-C35d to use RTCA DO-160F instead of RTCA DO-138 as the standard for Environmental Conditions and Test Procedures for Airborne Equipment.

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1.4.3 Transmitter Grant of Equipment Authorization
1. FCC
GMA 345 011-03520-00 and 011-03520-20 contain FCC ID: QOQWT32I GMA 345 011-03520-01 and 011-03520-21 contain FCC ID: 2ADHKBM83SM1
NOTE This device complies with part 15 of the FCC Rules. 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.
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. 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 the equipment off and on, the user is encouraged to try to correct the interference by one or more of the following measures:
· Reorient or relocate the receiving antenna · Increase the separation between the equipment and receiver · Connect the equipment into an outlet on a circuit different from that to which the receiver is
connected · Consult the dealer or an experienced radio/TV technician for help
FCC RF Radiation Exposure Statement: This equipment complies with FCC radiation exposure limits set forth for an uncontrolled environment. This equipment should be installed and operated with minimum distance 20mm between the radiator and your body. This transmitter must not be co-located or operating in conjunction with any other antenna or transmitter.
2. IC
GMA 345 011-03520-00 and 011-03520-20 contain IC: 5123A-BGTWT32I GMA 345 011-03520-01 and 011-03520-21 contain IC: 20266-BM83SM1
NOTE This device complies with Innovation, Science and Economic Development Canada license-exempt RSS standard(s). Operation is subject to the following two conditions: (1) this device may not cause interference, and (2) this device must accept any interference, including interference that may cause undesired operation of the device.
Cet appareil est conforme aux normes RSS sans licence du ministére Innovation, Sciences et Développement économique Canada. Son fonctionnement est soumis aux deux conditions suivantes : (1) ce périphérique ne doit pas causer d’interférences et (2) doit accepter toute interférence, y compris les interférences pouvant entraîner un fonctionnement indésirable de l’appareil.
3. Declaration of Conformity (GMA 345)
Hereby, Garmin declares that this product is in compliance with the Directive 2014/53/EU. The full text of the EU declaration of conformity is available at the following internet address: www.garmin.com/compliance.

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UK Declaration of Conformity Hereby, Garmin declares that this product is in compliance with the relevant statutory requirements. The full text of the declaration of conformity is available at the following internet address: www.garmin.com/compliance.
Radio Frequency/Protocol 2.4 GHz @ 2.42 dBm nominal

1.5 Operating Instructions
For operating instructions, refer to the applicable GMA 342 Pilot’s Guide (190-01878-00), GMA 345 Pilot’s Guide (190-01878-01), or GMA 345 3-COM Pilot’s Guide (190-01878-05).
1.6 Reference Documents
The following publications are sources of additional information for installing the GMA 342/345. The installer should read all referenced materials along with this manual before attempting installation.

Table 1-12 Reference Documents

Part Number 190-00149-01 190-00313-09 190-01878-00 190-01878-01 190-01878-05

Document GMA 340 Installation Manual Shield Block Installation Instructions GMA 342 Pilot’s Guide GMA 345 Pilot’s Guide GMA 345 3-COM Pilot’s Guide

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2 INSTALLATION OVERVIEW
2.1 Introduction
This section provides the necessary information for the installation and checkout of the GMA 342/345 Audio Panel. Installation of the GMA 342/345 will differ according to equipment location and other factors. The appendices contain interconnect wiring diagrams, mounting dimensions, and information pertaining to installation.
Careful planning and consideration of the suggestions in this section are required to achieve the desired performance and reliability from the GMA 342/345. The guidance of FAA advisory circulars AC 43.131B and AC 43.13-2B, where applicable, may be found useful for making retro-fit installations that comply with FAA regulations.
2.2 Installation Materials
2.2.1 Unit Configurations Table 2-1 Catalog Part Numbers

Model
GMA 342 Unit Only, SN Prefix 3YZ0 GMA 342 Standard Kit (includes items in Table 2-2), SN Prefix 3YZ0 GMA 342 Unit Only, SN Prefix 3YZ1 GMA 342 Standard Kit (includes items in Table 2-2), SN Prefix 3YZ1 GMA 345 Unit Only, SN Prefix 3Z00 GMA 345 Standard (includes items in Table 2-3), SN Prefix 3Z00 GMA 345 Unit Only, SN Prefix 3Z01 GMA 345 Standard (includes items in Table 2-3), SN Prefix 3Z01 GMA 345 3-COM Unit Only, SN Prefix 5JB0 GMA 345 3-COM Standard (includes items in Table 2-3), SN Prefix 5JB0 GMA 345 3-COM Unit Only, SN Prefix 5JB1 GMA 345 3-COM Standard (includes items in Table 2-3), SN Prefix 5JB1

Catalog Part Number
010-01319-10 010-01319-11 010-01319-12 010-01319-13 010-01319-00 010-01319-01 010-01319-02 010-01319-03 010-01319-20

Unit Only Part Number 011-03520-10 011-03520-10 011-03520-11 011-03520-11 011-03520-00 011-03520-00 011-03520-01 011-03520-01 011-03520-20

010-01319-21 011-03520-20

010-01319-22 011-03520-21

010-01319-23 011-03520-21

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2.3 Available Accessories 2.3.1 Standard Accessories

Table 2-2 Contents of GMA 342 Standard Installation Kit

Item

Part Number

Sub-Assy, Back Plate, GMA 342/345 (also used for GMA 240/340) (Table 2-4)

011-00678-00

Conn Kit, GMA 342/345 (also used for GMA 35/350) (Table 2-5)

011-02302-00

Sub -Assy, Audio Cables, 3.5 mm Right Angle

011-02412-00

SMP, Install Rack, GMA 342/345 (also used for GMA 240/340)

115-00262-00

Table 2-3 Contents of GMA 345 Standard Installation Kit

Item

Part Number

Sub-Assy, Back Plate, GMA 342/345 (also used for GMA 240/340) (Table 2-4)

011-00678-00

Conn Kit, GMA 342/345 (also used for GMA 35/350) (Table 2-5)

011-02302-00

SMP, Install Rack, GMA 342/345 (also used for GMA 240/340)

115-00262-00

Table 2-4 Contents of GMA 342/345 Back Plate Kit (011-00678-00, also used for GMA 240/340)

Item Pre-bagged screws “D” (Table 2-6)

Part Number 011-02650-03

Quantity 1

Nut Cover, SMP

115-00261-00

1

Connector Plate Assembly, DCP

125-00040-00

1

Nut, Std, English, SS, #6-32

210-00036-07

1

Screw, 4-40 x 0.250, PHP, SS/P, w/NYL

211-60234-08

2

Table 2-5 Contents of GMA 342/345 Conn Kit (011-02302-00, also used for GMA 35/350)

Item Backshell w/Hardware 44 pin

Part Number 011-00950-02

Quantity 2

Ground Adapter, Shell 1-3

011-01169-00

4

Screw 4-40 x 0.437, FLHP100, SS/P, Nylon

211-63234-11

4

Hi Density D-Sub Connector, Mil Crimp, 44 ckt

330-00185-44

2

Contact Pin, Mil Crimp, Size 22D

336-00021-00

94

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Table 2-6 Contents of GMA 342/345 Pre-bagged Screws “D” (011-02650-03)

Item Screw, 4-40 x 0.250, PHP, SS/P, w/NYL

Part Number 211-60234-08

Quantity 4

Cable Tie, 4.0″

231-10001-00

1

Table 2-7 Contents of GMA 342 Sub-Assy, Audio Cables, 3.5mm RA (011-02412-00)

Item Cable Assembly, Audio, 3.5mm to 3.5mm, Right Angle, 4 Pole Plug

Part Number 320-00571-00

Quantity 1

Cable Assembly, Audio, 3.5mm to 2.5mm, Right Angle, 4 Pole Plug

320-00571-01

1

2.3.2 ·
·
·
· · · · · ·
· ·

Additional Equipment Required
Cables: The installer will fabricate and supply all system cables. Interconnect wiring diagrams are detailed in Appendix C.
Hardware: #6-32 100° flat head screw (6 ea.) and #6-32 self-locking nut (6 ea.). Hardware required to mount the GMA 342/345 installation rack is not provided. Stereo headphone jacks (up to 6), microphone jacks (up to 6), 3.5mm stereo jacks (up to 2). Insulating type jacks or insulating washers should be used for all jacks to isolate them from aircraft chassis. Tool: 3/32″ Allen for tightening the unit into the rack and backplate. Push/Pull (that can be manually reset) circuit breaker (5 Amp recommended). Tie Wraps or Lacing Cord Ring Terminals (for grounding) #8 size, Yellow, Blue, and Pink. Silicone Fusion Tape (GPN 249-00114-00) to wrap the cable bundle. Solder Sleeves for terminating the shields of the cable to the GMA 342/345 backshell. See 190-00313-09 for part numbers. Heat shrink tubing SD card needed for updating software in the GMA 342/345. Garmin recommends using a 4 GB Sandisk® SD card.

Insulating Washers for Headset and Microphone Jacks can be found at the following suppliers:

Dallas Avionics

Digi-key

100053 – Shoulder Washer

SC1147-ND – Shoulder Washer

100054 – Flat Washer

SC1146-ND – Flat Washer

Mouser 502-S-1029 ­ Shoulder Washer 502-S-1028 ­ Flat Washer

Newark S1029 – Shoulder Washer S1028 – Flat Washer

Switchcraft S1029 ­ Shoulder Washer S1028 ­ Flat Washer
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2.4 Installation Considerations
The GMA 342/345 interfaces with various avionics equipment. Fabrication of a wiring harness is required. Sound mechanical and electrical methods and practices are required for installation of the GMA 342/345.
NOTE 3D audio is not available when using a mono headset or in aircraft wired with mono headset jacks. 3D audio (even if enabled), will not be available with mono audio headset jacks or mono headsets. It is recommended that stereo jacks and stereo headsets be used.
2.4.1 Auxiliary Inputs
For the GMA 345 3-COM unit, a single AUX button is used to select all 3 AUX inputs for simultaneous monitoring.
For the GMA 342 and 345 (2-COM version), two buttons (AUX1 and AUX2) are used to select/deselect the 3 AUX inputs. Pressing the AUX1 button selects/deselects the AUX 1 and AUX 3 receivers. Pressing the AUX2 button selects/deselects the AUX 2 receiver.
NOTE It is important to consider what sources are wired to the AUX 1 and AUX 3 inputs because when AUX 1 is selected, both AUX 1 and AUX 3 receiver audio will be heard together (this note is not applicable to the GMA 345 3-COM unit).

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2.4.2 Marker Beacon Antenna Installation
2.4.2.1 Location Considerations
The marker beacon antenna should be mounted on a flat surface on the underside of the aircraft body.
NOTE Do not install the antenna inside the aircraft. Installing the antenna inside the aircraft limits the antenna reception and increases the antennas susceptibility to radiation from components inside the aircraft.
Mount the antenna so that there is a minimum of structure between it and the ground radio stations. Locate it as far away as possible from transmitter antennas.
2.4.2.2 Marker Beacon Antenna Mounting
Install the antenna according to the antenna manufacturer’s instructions. If the antenna is being installed on a composite aircraft, ground planes must sometimes be added. Conductive wire mesh, radials or thin aluminum sheets embedded in the composite material provide the proper ground plane allowing the antenna pattern (gain) to be maximized for optimum performance.
2.4.2.3 Marker Beacon Antenna Cable
Use coaxial cable meeting the applicable aviation regulation for the marker beacon antenna. Any cable meeting specifications is acceptable for the installation. When routing antenna cables, observe the following precautions:
· All cable routing should be kept as short and as direct as possible · Avoid sharp bends · Avoid routing cables near power sources (e.g., 400 Hz generators, trim motors, etc.) or near power
for fluorescent lighting · Allow a 12 inch minimum separation between any other cables, including antenna cables (e.g
ADF, COM, NAV, GS, MARKER)

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2.4.2.4 Marker Beacon Antenna Cable Installation
This section provides guidance for terminating the coaxial cable into the D-Sub connector. See the system interconnect section for pin assignments.
NOTE Use coaxial cable meeting the applicable aviation regulation for the marker beacon antenna. Route the cable to the D-Sub as described in Section 2.4.2.3.
When terminating the coaxial cable into the D-Sub observe the following guidance (refer to Figure 2-1):
· Keep the distance from the end of the exposed shield to D-Sub as short as possible. · Ensure the distance from the beginning of the exposed shield to D-Sub is no more than
1.5 inches long. · Terminate the center conductor by directly connecting it to the D-sub through a crimp pin
without a pigtail.
Figure 2-1 below represents a suggested method for terminating the marker beacon coaxial cable using M17/128-RG400 terminated into a high density D-Sub connector. Refer to Table 2-8 for Crimp Tool, Pin, and Crimp Tool Insert part numbers.

Figure 2-1 GMA 342/345 Marker Beacon Coaxial Cable D-Sub Termination

Table 2-8 Pin and Crimp Tool Part Numbers

CRIMP TOOL
DANIELS MANUFACTURING CORP DMC M22520/2-01 GAGE AFM8 CRIMPING TOOL

PIN
Garmin Part Number 336-00021-00
Garmin Part Number 336-00044-00

CRIMP TOOL INSERT K42 K774

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2.4.3 Installation Approval Considerations for Pressurized Aircraft
Antenna and cable installations on pressurized cabin aircraft require FAA approved installation design and engineering substantiation data whenever such installations incorporate alteration (penetration) of the cabin pressure vessel by connector holes and/or mounting arrangements.
For needed engineering support pertaining to the design and approval of such pressurized aircraft antenna installations, it is recommended that the installer proceed according to any of the following listed alternatives:
1. Obtain approved antenna installation design data from the aircraft manufacturer. 2. Obtain an FAA approved Supplemental Type Certificate (STC) pertaining to and valid for the sub-
ject antenna installation. 3. Contact the FAA Aircraft Certification Office in the appropriate Region and request
identification of FAA Designated Engineering Representatives (DERs) who are authorized to prepare and approve the required antenna installation engineering data. 4. Locate an appropriate consultant FAA DER, by reviewing the “FAA Consultant DER Directory”, which can be found at the FAA “Designee and Delegation” web page. 5. Contact an aviation industry organization such as the Aircraft Electronics Association and request their assistance.
2.5 Cabling and Wiring
Cabling and Wiring
Refer to the interconnect examples in Appendix C for wire gauge guidance.
In some cases, a larger gauge wire such as AWG #18 or #20 may be needed for power connections. If using AWG #18 barrel contacts, ensure that no two contacts are mounted directly adjacent to each other. This minimizes the risk of contacts touching and shorting to adjacent pins and to ground.
Use wire and cable meeting the applicable aviation regulation. When routing wire and cable, observe the following precautions:
· Keep wire and cable as short and direct as possible · Avoid sharp bends · Avoid routing near power sources (e.g. 400 Hz generators, trim motors, etc) or near power of
fluorescent lighting · For Power and Ground use 2 individual wires for the units to the power source. Do not splice 2
wires to one at the unit for power and ground.
NOTE Avoid installing the unit near heat sources. If this is not possible, ensure that additional cooling is provided. Allow adequate space for installation of cables and connectors. The installer will supply and fabricate all of the cables.

2.6 Electrical Bonding
Electrical equipment, supporting brackets, and racks should be electrically bonded to the aircraft’s main structure. Refer to SAE ARP 1870 section 5 when aluminum surface preparation is required to achieve electrical bond. An equivalent OEM bonding procedure may also be substituted. The electrical bond should achieve direct current (DC) resistance less than or equal to 2.5 milliohms to local structure to where the equipment is mounted. Compliance should be verified by inspection using a calibrated milliohm meter.

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2.7 Cooling Air
The GMA 342/345 does not have provisions for attaching cooling air, however the thermal characteristics of the installation should always be assessed. An undesirable thermal condition could be created due to the unit’s own internal power dissipation combined with restricted ventilation, or due to heat generated by adjacent equipment. Limiting thermal build up, by means of fan or natural convection is always a good practice and recommended to increase the product life.
2.8 Configuration, and Adjustment Options
The GMA 342/345 has several configuration/adjustment options (see Section 2.8.6). These configuration/ adjustments are as follows:
· Wired Telephone Volume · Auxiliary 1 Volume · Auxiliary 2 Volume · Auxiliary 3 Volume · Alert 1 Volume · Alert 2 Volume · Alert 3 Volume · Alert 4 Volume · Speaker Volume · Marker Beacon Volume · Passenger Address Voume · Master Avionics Squelch (Section 2.8.1) · Marker Beacon Low Sensitivity Offset (Section 2.8.2) · Marker Beacon High Sensitivity Offset (Section 2.8.2) · High Cockpit Noise Option (Section 2.8.3) · Music In Isolation Option (Section 2.8.4)
2.8.1 Master Avionics Squelch (MASQ) Function
MASQ functions to prevent low level noise from being passed to the headset ear speakers, this is known as “squelching” or muting the audio. To “break” or “open” squelch means that enough audio signal is present that the signal is passed through and can be heard. Increasing this setting increases the signal level required to break/open squelch. If needed, adjust the MASQ SQ level so the audio background noise is muted.
2.8.2 Marker Beacon Sensitivity Offset
Sensitivity Offset From Calibration. At default offset level, marker sensitivity is calibrated to 200 uV for high sensitivity mode and 1000 uV for low sensitivity mode. Adjust up (right) if more sensitivity (earlier indication, longer lamp dwell over beacon, lower threshold voltage) is desired. Adjust down (left) if less sensitivity (later indication, shorter lamp dwell over beacon, higher threshold voltage) is desired. The low and high sensitivity settings are independent and do not affect each other.
2.8.3 High Cockpit Noise Option
Enable to help reduce intercom background noise in very high noise cockpit environments. Disabled by default.
2.8.4 Music In Isolation Option
Enable to allow pilot and copilot to hear selected music when PILOT or CREW isolation mode is active. Disabled by default.

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2.8.5 DIP Switch Configuration
The DIP switches are used to select the configuration settings listed in Table 2-9, and are located on the right side of the unit next to the SD card slot as shown in Figure 2-2.

SD CARD SLOT DIP SWITCHES
Figure 2-2 SD Card Slot and DIP Switch Locations
2.8.5.1 GMA 342/345 DIP Switch Configuration Settings The GMA 342/345 DIP switch configuration settings are listed in Table 2-9. Per the label attached to the top cover of the unit, the down switch position is ON, the up switch position is OFF.

Table 2-9 DIP Switch Configuration Settings

Switch 1
2
3
4 5 6 7 8

Function ENABLED KEYED ICS
PILOT IN RIGHT SEAT
MUTE ON COM TX
PASSENGERS ALWAYS GET MUSIC 2 RESERVED RESERVED RESERVED CONFIGURATION LOCKOUT

Description
When set to ON, the intercom system (ICS) will only allow intercom MIC audio to be heard when the corresponding ICS KEY for the MIC position is pressed. When set to ON, auto squelch will NOT be active.
This setting is for intercom 3D audio. Normally the Pilot will be positioned to the left in the Copilot’s headset, and the Copilot will be positioned to the right in the Pilot’s headset. When set to ON, this setting reverses that so the Pilot is positioned to the right in the Copilot’s headset, and the Copilot is positioned to the left in the Pilot’s headset. For the GMA 345 3-COM unit, this also sets which knobs control Pilot volumes vs. Copilot/Passenger volumes.
When set to ON, the monitored COM radio is muted during micselected COM transmission (mic-selected COM is still heard, but not the monitored COM radio).
When set to ON, regardless of what the music source is set to (1, 2, Bluetooth transceiver on GMA 345, or 1, 2, Jack on GMA 342), regardless of what state of the MUSIC button is set to (ON or OFF), the passengers will always get MUSIC 2.
LEAVE SWITCH IN OFF POSTION
LEAVE SWITCH IN OFF POSTION
LEAVE SWITCH IN OFF POSTION
When set to ON, this prevents use of the GMA 342/345 config mode UI.

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2.8.6 Front Panel Configuration
NOTE The GMA 345 (2-COM version) is used as the example for this section. Some of the GMA 345 3-COM unit button text labels differ from the 2-COM version. Where this occurs, the 3-COM unit text label will be indicated in brackets following the 2-COM version button text label. For example: SPKR key [COM3 MIC for 3-COM unit].
Enter configuration mode by holding down the COM1 MIC and SPKR [COM3 MIC for 3-COM unit] buttons while turning the unit on.
When in configuration mode:
· Pressing the PLAY button will annunciate the current software/database product version, e.g. “system two dot zero zero”.
· Pressing the COM1 MIC key selects volume mode. Press the COM1 MIC key until the desired volume is annunciated, e.g “auxiliary one volume”.
· Pressing the COM2 MIC key selects Master Avionics Squelch mode. · Pressing the SPKR [COM3 MIC for 3-COM unit] key annunciates the current option, e.g. “Music
During Isolation Enabled” or “Cockpit High Noise Disabled”. Cockpit High Noise configuration applies more filtering to the intercom mic audio. In higher noise cockpits, this can improve voice intelligibility. In moderate to lower noise cockpits, the default filter usually provides better intelligibility. Music During Isolation configuration changes the behavior of the PILOT and CREW isolation modes such that music is still heard by the pilot and copilot when they are isolated from the passengers.
· Pressing the TEL key selects Marker Beacon sensitivity offset mode. Press the TEL key until the desired Marker Beacon sensitivity mode is annunciated, e.g. “Marker Beacon Low Sensitivity”.
· Pressing the PILOT key increases the selected setting as indicated by the LEDs on the Level Bar. · Pressing the CREW key decreases the selected setting as indicated by the LEDs on the Level Bar. · When adjusting Options in configuration mode, the PILOT and CREW keys are used to indicate
the current state and change the state. If the option is enabled, the PILOT key is lit solid and the CREW key flashes (indicating that the CREW key can be pushed to disable the option). If the option is disabled, the CREW key is lit solid and the PILOT key flashes (indicating that the PILOT key can be pushed to enable the option). The Level Bar is not used when in the options mode.
· The LEDs in the Level Bar (Figure 2-3) light to indicate an increase/decrease in the selected setting.
· Pressing COM1 and MKR buttons simultaneously resets the configuration and operating state back to factory defaults.

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ABOUT: PRESSING AUDIBLY ANNUNCIATES SOFTWARE AND DATABASE PRODUCT VERSIONS (BOOT BLOCK, SYSTEM, AUDIO, AND BLUETOOTH).

LEVEL BAR: TOP ROW OF KEY ANNUNCIATORS INDICATES THE SELECTED LEVEL OF ITEM BEING ADJUSTED (VOLUME AND MASQ ONLY). THE ANNUNCIATORS TURN ON FROM LEFT TO RIGHT AS THE ADJUSTMENT LEVEL INCREASES.

VOLUMES: PRESSING CYCLES THROUGH VOLUMES (AUX 1, 2, 3; ALERT 1, 2, 3, 4; WIRED TELEPHONE; MARKER BEACON; SPEAKER; SPEAKER PA).

MASQ: PRESSING ENABLES MASQ ADJUSTMENTS.

MARKER: PRESSING CYCLES THROUGH MARKER SENSITIVITY OFFSETS.

OPTIONS: PRESSING CYCLES THROUGH OPTIONS (COCKPIT HIGH NOISE, MUSIC DURING ISOLATION).

ADJUSTMENTS: PILOT’ USED FOR INCREASING LEVELS OR ENABLING OPTIONS.CREW’ USED FOR DECREASING LEVELS OR DISABLING OPTIONS.

Figure 2-3 Front Panel Configuration

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2.8.7 Hardwired Configuration Options
The configuration options in Table 2-10 are available by wiring the inputs to a pushbutton to ground (see Figure C-2 and Figure C-3).

Table 2-10 Hardwire Configuration Options

Connector Pin

J3401

16

J3401

24

J3402

13

J3402

20

J3402

22

J3402

30

J3402

19

J3402

12

*Active Low

Description PILOT ICS KEY
COM ACTIVE OUT
PASSENGER ICS KEY
COM SWAP
PLAY KEY
COPILOT ICS KEY PA MODE SELECTED PA MUTE OUT

Type Input
Output
Input Input Input Input Output Output

Function
If DIP switch 1 is on, this active low input, when grounded, will allow microphone audio to the intercom from Pilot MIC.
This output is active when Receiving selected COM audio or when transmitting on the MIC selected COM. This output can be used to connect to other devices to inhibit other devices from playing audio into the GMA 342/345 while there is COM activity.
If DIP switch 1 is on, this active low input, when grounded, will allow microphone audio to the intercom from Passenger MIC.
When grounded the MIC selected COM will swap. For the GMA 345 3-COM unit, this cycle includes selection of COM 3 MIC (1, 2, 3, 1, 2, 3, …).
When grounded the last voice recorded message will play. While playing, if grounded again, the previous message will play.
If DIP switch 1 is on, this active low input, when grounded, will allow microphone audio to the intercom from Copilot MIC.
This output is active when the GMA 342/345 is in PA mode.
This output is active when the GMA 342/345 is in PA mode, and the Pilot or Copilot PTT is active.

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2.9 Updating Software Updating software is performed using an SD card. Garmin recommends using a 4GB Sandisk® SD Card. 2.9.1 Checking Software Version
The GMA 342/345 comes pre-loaded with system software. However, if the software is out of date, it is recommended that current software be loaded from an SD card into the GMA 342/345.
The current version of software can be retrieved in the configuration operating mode. See Section 2.8.6 for instructions.
2.9.2 Creating a Software Loader SD Card
The software update mode allows the installer to load unit software using an SD software loader card.
NOTE The application to create a loader card requires Windows 2000, XP, Vista, Windows 7, or Windows 10. There is no Mac support at this time.
6. Go to the Dealer Resource Center at dealers.garmin.com. 7. Download the GMA 342/345 software to your PC. 8. Ensure that an SD card (Garmin recommends a Sandisk® brand 4GB SD card) is connected to the
PC in the SD card slot. 9. Run the executable file that was downloaded and follow the prompts on the screen to create the
software loader card. 10. After the card has been created, select finish to complete the process. 11. Remove the card from the slot. The loader card is now ready to use. 2.9.3 Loading Software to the GMA 342/345 1. Remove the unit from the rack using a 3/32″ Allen tool. 2. The SD card slot is on the right side of the unit next to the DIP switches (see Figure 2-2). Insert
the SD card with pins facing down (toward the bottom of the unit). 3. Install the unit back into the rack using a 3/32″ Allen tool. 4. Press and hold the following two keys while turning the unit on:
a) For GMA 342 and 345 (2-COM version): COM1 MIC key and TEL key. b) For GMA 345 3-COM unit: COM1 MIC key and COM3 MIC key. 5. The GMA 342/345 will begin checking the SD card for updated software. a) Do not turn the GMA 342/345 off or remove power during the update process. b) The top row of buttons, from left to right, will indicate the progress of the update process. c) If a problem is encountered during the update process, all buttons on the top row will flash at
a 1 Hz rate.

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6. If a problem is encountered during the update process, follow the below steps for possible solutions.
a) Use the Pilot Knob to power cycle the GMA 342/345, then perform the process again.
b) Attempt to re-download the GMA 342/345 software to the PC, recreating the loader SD card, and perform the process again.
c) Recreate the loader card using the recommended Sandisk® brand 4GB SD card, and attempt the update process again.
d) If still having difficulty performing the update, contact Garmin Aviation Technical support.
7. Once the update process is finished the GMA 342/345 will automatically reboot back into normal operating mode.
8. The update card does not need to be removed after the update process and can be left in the GMA 342/345 at the installer’s discretion.
Once the unit has been updated, verify the correct software version is installed (see Section 2.8.6 for instructions). For the GMA 345 only, if a Bluetooth firmware update is included with the software update, the Bluetooth firmware will be updated automatically after the GMA 345 reboots. While a Bluetooth firmware update is being performed in the GMA 345, the Bluetooth annunciator will blink in an ON – ON – OFF pattern for several minutes. When the Bluetooth software update is completed, the Bluetooth functions will return to normal operation.
2.10 Electrical Noise
Because the audio panel is a point in the aircraft where signals from many pieces of equipment are brought together, care must be taken to minimize effects from coupled interference and ground loops.
Coupled interference can sneak into audio system interconnecting cables when they are routed near large AC electric fields, AC voltage sources, and pulse equipment (strobes, spark plugs, magnetos, EL displays, CRTs, etc). Interference can also couple into audio system interconnecting cables by magnetic induction when they are routed near large AC current-carrying conductors or switched DC equipment (heaters, solenoids, fans, autopilot servos, etc).
Ground loops are created when there is more than one path in which return currents can flow, or when signal returns share the same path as large currents from other equipment. These large currents create differences in ground potential between the various equipment operating in the aircraft. These differences in potential can produce an additive effect at an audio panel signal input.
The audio panel may “see” the desired input signal plus an unwanted component injected by ground differentials, a common cause of alternator-related noise. This is the main reason why all audio jacks should be isolated from ground. Terminating audio shields just at one end eliminates another potential ground loop injection point.
Single-point grounding cannot be overstressed for the various avionics producing and processing audio signals. Single-point, in this context, means that the various pieces of equipment share a single common ground connection back to the airframe. Good aircraft electrical/charging system ground bonding is also important.
The wiring diagrams and accompanying notes in this manual should be followed closely to minimize noise effects.

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2.11 Mounting Requirements The GMA 342/345 mounting surface must be capable of providing structural support and electrical bond to the aircraft to minimize radiated EMI and provide protection from High-Intensity Radiation Fields (HIRF). The GMA 342/345 is mounted using a GMA unit rack (Figure 2-4). See Section 3.6 for installation instructions.
NOTE Rear support is recommended to ensure a sturdy mount.
CAUTION The top cover of the unit has a connector number (1 and 2) stamped into it and centered in front of each connector. The 011-00678-00 backplate also has a stamped number on it. To prevent damage to the unit, verify the connectors are positioned correctly (connector 1 is connected in position 1) for the number 1 and number 2 locations. The stamped number 1 refers to J3401, and 2 refers to J3402.

Figure 2-4 GMA Unit Rack (115-00262-00)

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3 INSTALLATION PROCEDURE
3.1 Unpacking Unit
Carefully unpack the equipment and make a visual inspection of the unit for evidence of damage incurred during shipment. If the unit is damaged, notify the carrier and file a claim. To justify a claim, save the original shipping container and all packing materials. Do not return the unit to Garmin until the carrier has authorized the claim.
Retain the original shipping containers for storage. If the original containers are not available, a separate cardboard container should be prepared that is large enough to accommodate sufficient packing material to prevent movement.
3.2 Electrical Connections
All electrical connections to the GMA 342/345 are made through two 44-pin D-subminiature connectors (see Figure 3-1). Section 4 defines the electrical characteristics of all input and output signals. Required connector and associated hardware are supplied in the connector kits. Refer to Section 2.3 for the GMA 342/345 standard kit part numbers that contain the necessary hardware. See Appendix C for interconnect wiring diagrams.
CAUTION Check wiring connections for errors before inserting the GMA 342/345 into the rack. Incorrect wiring could cause internal component damage.

Table 3-1 Pin Contact Part Numbers

Manufacturer

44 pin D-Subminiature Connectors (P3401, P3402)

18-20 AWG (Power and Ground Only)

22-28 AWG

Garmin P/N

336-00044-00*

336-00021-00

Military P/N

N/A

M39029/58-360

*Used for 18 AWG wire, is not included in the GMA 342/345 installation kits, and is not needed to install a GMA 342/345. GPN 336-00021-00 is used for 22 AWG wire and is included in the GMA 342/345 installation kits. Use the 336-00044-00 if installing 18 AWG wire for Power and Ground.

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Table 3-2 Recommended Crimp Tools

Manufacturer

Hand Crimping Tool

Military P/N Positronic AMP Daniels Astro

M22520/2-01 9507 601966-1 AFM8 615717

18-20 AWG

Positioner

Insertion/ Extraction Tool (Note 2)

N/A

M81969/1-04

9502-11 M81969/1-04

N/A

91067-1

K774

M81969/1-04

N/A

M81969/1-04

22-28 AWG

Positioner

Insertion/ Extraction Tool

M22520/2-09 M81969/1-04

9502-3

M81969/1-04

601966-6

91067-1

K42

M81969/1-04

615725

M81969/1-04

NOTE
1. Non-Garmin part numbers shown are not maintained by Garmin and consequently are subject to change without notice.
2. Extracting #18 and #20 contacts requires that the expanded wire barrel be cut off from the contact. It may also be necessary to push the pin out from the face of the connector when using an extractor due to the absence of the wire. A new contact must be used when reassembling the connector.
3.3 Antenna Installation
Install the antenna according to the antenna manufacturer’s instructions.
3.3.1 Antenna Cable Connectors
The antenna cable requires a BNC plug connector. Follow BNC connector manufacturer instructions for assembly of the BNC connector.
3.4 Shield Block Backshell Installation Instructions
3.4.1 Backshell Installation Parts
The GMA 342/345 connector kit includes two Garmin backshell assemblies. Garmin’s backshell connectors give the installer the ability to quickly and easily terminate shield grounds at the backshell housing using the Shield Block. To assemble the backshell connectors and grounding system, refer to instructions provided in the Shield Block Installation Instructions (190-00313-09).

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3.5 Backshell Assembly
The GMA 342/345 connector kit includes two Garmin backshell assemblies. Garmin’s backshell connectors give the installer the ability to quickly and easily terminate shield grounds at the backshell housing using the Shield Block. To assemble the backshell connectors and grounding system, refer to instructions provided in the Shield Block Installation Instructions (190-00313-09).

J3402

J3401

Figure 3-1 Rear View of Rack and Connectors
3.6 Unit Installation
CAUTION Do not use excessive force when inserting the GMA 342/345 into the rack. This may damage the connectors, unit, and/or rack. If heavy resistance is felt during installation, stop! Remove the GMA 342/345 and identify the source of resistance.
3.6.1 GMA 342/345 Installation:
For final installation and assembly, refer to the outline and installation drawings Figure B-1 and Figure B-2 1. Assemble the backshell as described in Section 3.5. 2. Connect both backshells to the rear plate using the screws provided in the connector kit (Figure B-2). 3. Mount the GMA 342/345 to the GMA rack as shown on the installation drawing. 4. Assemble the rear plate into the GMA 342/345 unit rack. 5. Insert the GMA 342/345 into the rack, noting proper orientation as shown on the installation drawing. 6. Lock the GMA 342/345 in place using a 3/32″ Allen tool.

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3.7 Post Installation Checkout
CAUTION Check wiring connections for errors before inserting the GMA 342/345 into the rack. Incorrect wiring could cause internal component damage.
An in-aircraft checkout may be performed in the aircraft on the ramp with known good microphone, headset, and avionics receivers.
3.7.1 Failsafe Operation Check
1. Remove power to the unit by pulling the GMA 342/345 breaker. 2. Connect a mono headset to the pilot’s headset output jack and pilot’s mic jack.
NOTE Use of a true mono headset is required for this test to ensure proper wiring even if a stereo jack is provided in the installation. Wiring left channel (tip contact) and right channel (ring contact) backwards will cause failsafe mode not to function with mono headsets. Use of a true mono headset is required for this test (not a stereo headset with a mono/ stereo switch because headset manufactures differ on how they accomplish this switching). This will guarantee the condition of the right channel (ring terminal) being shorted to the return (sleeve terminal) by the mono headset’s plug. This short occurs because of the physical design of the headset plug contacts and is an inevitable consequence of plugging a mono headset into a stereo jack. During power-on operation, this short will not damage the audio panel. 3. Verify that COM1 transceiver can be heard in the pilot’s headset. 4. Verify that COM1 can key and transmit the pilot’s mic audio by verifying received sidetone or checking reception of the transmission with another radio tuned to receive this transmission (verify Pilot PTT and mic operation is delivered to this transceiver). 5. Apply unit power by restoring the audio breaker to the normal operating position
3.7.2 Transceiver Operational Check
1. Perform a ramp test radio check by exercising the installed transceivers, microphone, microphone key, and audio over the headphone.
2. Verify that communications are loud and clear and PTT operation is correct.
3.7.3 Aircraft Receivers Check
1. Select the audio source corresponding to each installed avionics unit and check for audio over the headsets.
2. Verify each installed unswitched (alert) source can be heard when the source is instructed to play a simulated alert/message.
NOTE For the GMA 342 and 345 (2-COM version) unit AUX inputs, pressing the AUX1 button selects/deselects the AUX 1 and the AUX 3 receiver. Pressing the AUX2 button selects/ deselects the AUX 2 receiver.

NOTE For the GMA 345 3-COM unit, a single AUX button is used to select all 3 AUX inputs for simultaneous monitoring.

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3.7.4 Music System Check
1. Set GMA 342/345 to ALL mode with Pilot and Crew button off.
2. Connect a stereo audio source to MUSIC 1. Verify that stereo audio is heard over all headset positions when MUSIC 1 is selected as the music source and the MUSIC LED is on. Verify that music volume adjustment is working properly for Pilot, Copilot, and Passengers (if passenger headsets are wired).
3. Connect a stereo music source to MUSIC 2. Verify that stereo audio is heard when MUSIC 2 is selected as the music source and MUSIC LED is on.
3.7.5 Bluetooth Music System Check (GMA 345 only)
Use the following steps to Pair and wirelessly connect a Bluetooth equipped phone or tablet to the GMA 345. Pairing mode allows a new device to discover and create a connection to the GMA 345. Additionally, pairing mode is used to forcefully disconnect a device currently connected to the GMA 345.
NOTE The Bluetooth annunciation is illuminated only when a Bluetooth device is connected.
1. Press and hold the TEL (PAIR) Key for one second to enter pairing mode. The Bluetooth annunciator flashes to indicate the GMA 345 is in pairing mode and “Pairing Enabled” audio is played. Once the Bluetooth annunciator flashes, the GMA is discoverable for two minutes, or until a device is paired or connected. While discoverable, a Bluetooth enabled device (e.g., cellphone or tablet) can find and pair with the GMA. Refer to the device’s instruction manual for information on how to pair and connect to a new Bluetooth device. Once paired and connected, the Bluetooth annunciator on the GMA stops flashing and remains lit as long as the Bluetooth connection is active. The GMA remembers the last 10 paired devices. When the paired devices list is full and a new device is paired, the least recently connected device is removed from the paired device list.
2. Play music on a device using the Bluetooth connection and adjust the device volume near maximum.
3. With the MUSIC button on and the Bluetooth music system selected, verify music is heard in the connected headsets and that the music volume on the GMA 345 adjusts the volume in the headset.
4. Disable radio and ICS muting by pressing and holding the AUX2 key.
NOTE To ensure the music audio is not being muted by ICS or by COM audio, disable radio and ICS muting. Also, deselect the PILOT or CREW buttons so that there is no ICS Isolation.

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3.7.6 Speaker Check 1. If a speaker was installed, select SPKR and receive COM audio on the selected COM. When the speaker is selected, the selected Receivers on the GMA 342/345 (COM, NAV, AUX) should be heard from the speaker. 2. Initiate PA (Passenger Address) mode and verify that from both the pilot and copilot position, the crew position that is pressing PTT has the respective mic audio delivered to the speaker clearly.
NOTE If a loud squeal is heard while testing the PA, it is likely caused by acoustic feedback between the speaker and the mic. Physically separating the speaker and microphone should resolve this issue. If the speaker and mic cannot be placed sufficiently apart, a lower volume configuration should be used. Some installations may not have sufficient distance between the speaker and crew seat positions for reliable PA to speaker operation. In these conditions, the “PA to speaker” volume can be set very low and PA audio will still be delivered to the headsets.
CAUTION Be sure to check all aircraft control movements before flight is attempted to ensure that the wiring harness does not touch any moving part.
3.7.7 Marker Beacon Operation (if installed) 1. With a marker signal generator/transmitter test set, generate Marker Tones. 2. From the pilot headset position, verify that marker audio can be heard when selected. 3. If the system includes integrated lamp annunciation and/or if external lamps are installed, verify that each marker tone illuminates the proper lamp.
NOTE The Marker Lamps will operate even if the marker audio is not selected. Outer Marker ­ Blue Lamp ­ 400 Hz (AM or received audio tone) Middle Marker ­ Amber Lamp ­ 1300 Hz (AM or received audio tone) Inner Marker ­ White Lamp ­ 3000 Hz (AM or received audio tone)
NOTE To adjust the Marker beacon volume, put the unit into configuration mode as shown in Section 2.8.6, cycling to the Marker Beacon volume, then adjusting with the crew and pilot buttons as described in Section 2.8.6.
4. Verify that during HI SENS operation, the RF threshold is more sensitive (marker audio/indication occurs as a lower RF power) when the GMA 342/345 is in HI SENSE.

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3.7.8 Other Optionally Installed I/O
Verify any other installed/configured inputs and outputs operate properly. Possible examples include: ICS keys, Play key, PA Mute output, PA Mode Selected output, COM Active output, and Middle Marker Sense output.
This completes the in-aircraft post installation checkout. Perform a flight test after installing the unit to ensure satisfactory performance of the audio functions.
3.8 Continued Airworthiness
Other than for regulatory checks, maintenance of the GMA 342/345 is “on condition” only. Periodic maintenance of the GMA 342/345 is not required.
3.9 Diagnostics Information The GMA 342/345 is capable of displaying diagnostics information while in normal mode of operation. To show the diagnostics information press the PLAY button for five seconds. While still holding the PLAY button, all button annunciators will turn off except for those associated with certain diagnostic states. All button annunciators are off if no diagnostic information is available. The image below depicts which button annunciators are associated with which diagnostic states.

NOTE The GMA 345 (2-COM version) is used as the example for this section. Some of the GMA 345 3-COM unit button text labels differ from the 2-COM version.

Press-n-Hold PLAY Diagnostics Mode

COM2 Pilot HS Right Short

NAV2 Copilot HS Right Short

COM1 Pilot HS Left Short

NAV1 Copilot HS Left Short

MUSIC Pass HS Left Short

AUX1 Pass HS Right Short

PILOT Hardware Fault

CREW Software Load Fault

Figure 3-2 Diagnostics Mode (2-COM version shown) · A Headset Short indication means that the unit has detected the associated headset wire is shorted
to ground or to another headset channel. No headset short should be detected if the headset jack is wired for a stereo jack, and the headset is a stereo headset. A headset short may be detected for a mono headset. · A Hardware Fault indication means the unit has detected an internal unrecoverable fault. Contact Garmin Aviation Customer support for assistance. · A Software Load Fault indication means the previous software update didn’t complete successfully. Retry loading software from the loader card to resolve this fault.

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3.10 Disabling Bluetooth Connectivity (GMA 345 only) To aid in troubleshooting the GMA 345, Bluetooth connectivity can be disabled. To disable Bluetooth connectivity:
1. Press and hold the TEL key for 5 seconds. 2. An audio clip will be heard in the headset that says “Bluetooth Disabled”. 3. To re-enable Bluetooth connectivity without power cycling, press and hold the TEL key for 5
seconds. 4. An audio clip will be heard in the headset that says “Bluetooth Enabled”.
NOTE Once disabled, the GMA 345 Bluetooth connectivity does not remain disabled after power cycling. The GMA 345 Bluetooth connectivity is always enabled following a power cycle.

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4 SYSTEM INTERCONNECTS
4.1 Connector Description
The GMA 342/345 has two 44-pin connectors located at the rear of the unit designated J3401 and J3402 which are oriented as shown in Figure 4-1. The GMA 342/345 is installed into a rack with shield block backshells.

J3402

J3401

4.2 Pin List

Figure 4-1 Rear View of Backplate and Connectors

Figure 4-2 Rear Connectors J3401 & J3402, Viewed from Back of Unit

J3401 and J3402 pins are configured as shown in Figure 4-2. J3401 and J3402 pin assignments are given in Table 4-1, Table 4-2, and Appendix C.
Following the Table 4-1 & Table 4-2, additional tables group pin connections by function.
An asterisk (*) following a signal name denotes that the signal is active low logic. Active low inputs are connected to ground to activate. Active low outputs sink current to ground when active.
4.2.1 J3401 Connector

Table 4-1 J3401 Pin Assignments

Pin

Pin Name

I/O

1 MARKER ANTENNA HI

IN

2 MARKER ANTENNA LO

—

WIRED TEL AUDIO IN (GMA 342/345)

3

IN

COM 3 AUDIO IN (GMA 345 3-COM unit only)

WIRED TEL AUDIO LO (GMA 342/345)

4

—

COM 3 AUDIO LO (GMA 345 3-COM unit only)

*Denotes Active Low (Inputs: ground to activate; Outputs: grounded when active)

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Table 4-1 J3401 Pin Assignments

Pin

Pin Name

WIRED TEL MIC OUT (GMA 342/345) 5
COM 3 MIC OUT (GMA 345 3-COM unit only)

RESERVED (GMA 342/345) 6
COM 3 MIC KEY* OUT (GMA 345 3-COM unit only)

7 RCVR 4 AUDIO IN HI (AUX 2)

8 RCVR 4 AUDIO IN LO (AUX 2)

9 COM 1 AUDIO IN HI

10 COM 1 AUDIO LO

11 COM 1 MIC AUDIO OUT HI

12 COM 1 MIC KEY* OUT

13 COM 2 AUDIO IN HI

14 COM 2 AUDIO LO

15 COM 2 MIC AUDIO OUT HI

16 PILOT ICS KEY*

17 NAV 1 AUDIO IN HI

18 NAV 1 AUDIO IN LO

19 NAV 2 AUDIO IN HI

20 NAV 2 AUDIO IN LO

21 RCVR 3 AUDIO IN HI (AUX 1)

22 RCVR 3 AUDIO IN LO (AUX 1)

23 RCVR 5 AUDIO IN HI (AUX 3)

24 COM ACTIVE* OUT

RESERVED (GMA 342/345) 25
WIRED TEL AUDIO IN HI (GMA 345 3-COM unit only)

RESERVED (GMA 342/345) 26
WIRED TEL AUDIO IN LO (GMA 345 3-COM unit only)

RESERVED (GMA 342/345) 27
WIRED TEL MIC OUT HI (GMA 345 3-COM unit only)

RESERVED (GMA 342/345) 28
WIRED TEL MIC OUT LO (GMA 345 3-COM unit only)

29 ALERT 3 AUDIO IN HI

30 COM 2 MIC KEY* OUT

31 ALERT 1 AUDIO IN HI

32 ALERT 1 AUDIO IN LO

33 PILOT MIC AUDIO IN HI

34 PILOT MIC KEY* IN

35 PILOT MIC AUDIO IN LO

*Denotes Active Low (Inputs: ground to activate; Outputs: grounded when active)

I/O
OUT
OUT
IN -IN -OUT OUT IN -OUT IN IN -IN -IN -IN OUT -IN -IN -OUT -OUT IN OUT IN -IN IN —

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Table 4-1 J3401 Pin Assignments

Pin

Pin Name

36 INNER MARKER LAMP OUT

37 OUTER MARKER LAMP OUT

38 MIDDLE MARKER LAMP OUT

39 MIDDLE MARKER SENSE OUT

40 PASS HEADSET AUDIO OUT LEFT

41 PASS HEADSET AUDIO OUT RIGHT

42 PASS HEADSET AUDIO OUT LO

43 ALERT 3, 4, AUX 3 AUDIO IN LO

44 ALERT 4 AUDIO IN HI

*Denotes Active Low (Inputs: ground to activate; Outputs: grounded when active)

I/O OUT OUT OUT OUT OUT OUT
–IN

4.2.2 J3402 Connector

Table 4-2 J3402 Pin Assignments

Pin

Pin Name

1 PILOT HEADSET AUDIO OUT LO

2 COPILOT HEADSET AUDIO OUT LO

3 COPILOT HEADSET AUDIO OUT LEFT

4 COPILOT HEADSET AUDIO OUT RIGHT

5 LIGHTING BUS 14V LO/28V LO

6 LIGHTING BUS 14V HI/28V LO

7 LIGHTING BUS 14V HI/28V HI

8 AIRCRAFT POWER

9 AIRCRAFT POWER

10 POWER GROUND

11 POWER GROUND

12 PA MUTE* OUT

13 PASSENGER ICS KEY*

14 ALERT 2 LO, FAILSAFE AUDIO IN LO

15 ALERT 2 AUDIO IN HI

16 PILOT HEADSET AUDIO OUT LEFT

17 RS-232 IN

18 RS-232 OUT

19 PA MODE SELECTED*

20 COM SWAP*

21 GROUND

22 PLAY KEY*

*Denotes Active Low (Inputs: ground to activate; Outputs: grounded when active)

I/O –OUT OUT -IN IN IN IN –OUT IN -IN OUT IN OUT OUT IN -IN

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Table 4-2 J3402 Pin Assignments

Pin

Pin Name

23 MUSIC 1 IN LEFT

24 MUSIC 1 IN RIGHT

25 MUSIC 1 IN LO

26 MUSIC 2 IN LEFT

27 MUSIC 2 IN RIGHT

28 MUSIC 2 IN LO

29 FAILSAFE WARN AUDIO IN HI

30 COPILOT ICS KEY*

31 PILOT HEADSET AUDIO OUT RIGHT

32 COPILOT MIC AUDIO IN HI

33 COPILOT MIC KEY* IN

34 COPILOT MIC AUDIO IN LO

35 PASS 1 MIC AUDIO IN HI

36 PASS 1 MIC AUDIO IN LO

37 PASS 2 MIC AUDIO IN HI

38 PASS 2 MIC AUDIO IN LO

39 PASS 3 MIC AUDIO IN HI

40 PASS 3 MIC AUDIO IN LO

41 PASS 4 MIC AUDIO IN HI

42 PASS 4 MIC AUDIO IN LO

43 SPEAKER AUDIO OUT LO

44 SPEAKER AUDIO OUT HI

*Denotes Active Low (Inputs: ground to activate; Outputs: grounded when active)

I/O IN IN -IN IN -IN IN OUT IN IN -IN -IN -IN -IN –OUT

4.3 Aircraft Power
The GMA 342/345 has four pins for aircraft power bus inputs. Use one wire for each of the pins connecting to the aircraft power and ground. Do not splice the power and ground pins at the unit and use only one wire to aircraft power and ground.
Table 4-3 Aircraft Power

Pin

Connector

Pin Name

I/O

8

J3402 AIRCRAFT POWER

IN

9

J3402 AIRCRAFT POWER

IN

10

J3402 POWER GROUND

—

11

J3402 POWER GROUND

—

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4.4 Lighting Bus
The GMA 342/345 can be configured to track a 14 or 28 Vdc lighting bus using these inputs. Refer to Appendix C for lighting interconnections.
Backlighting refers only to the lighting of the text labels on the front panel and is controlled by the inputs in Table 4-4. The brightness of the LED annunciators that illuminate each key when selected is controlled by a photocell that operates independently of the backlight input.

NOTE If the lighting bus inputs are not connected, the backlighting will use the photocell.
Table 4-4 Lighting Bus

Pin

Connector

Pin Name

I/O

5

J3402 LIGHTING BUS 14V LO/28V LO

—

6

J3402 LIGHTING BUS 14V HI/28V LO

IN

7

J3402 LIGHTING BUS 14V HI/28V HI

IN

4.5 RS-232
The RS-232 outputs conform to EIA Standard RS-232C with an output voltage swing of at least ±5V when driving a standard RS232 load.
Table 4-5 RS-232

Pin

Connector

17

J3402 RS-232 IN

18

J3402 RS-232 OUT

Pin Name

I/O IN OUT

4.6 Audio Inputs/Outputs and Mic Keys 4.6.1 Mic Audio Inputs and Mic Keys
Table 4-6 Mic Audio Inputs and Mic Keys

Pin Connector

Pin Name

Description

I/O

34

J3401 PILOT MIC KEY* IN

Enables respective MIC audio into

IN

33

J3402 COPILOT MIC KEY* IN

the selected transceiver unit

IN

33

J3401 PILOT MIC AUDIO IN HI

Pilot Mic audio input and ground

IN

35

J3401 PILOT MIC AUDIO IN LO

reference

—

32

J3402

COPILOT MIC AUDIO IN HI Copilot Mic audio input and ground

IN

34

J3402

COPILOT MIC AUDIO IN LO reference

—

35

J3402

PASS 1 MIC AUDIO IN HI

Passenger 1 Mic audio and ground

IN

36

J3402

PASS 1 MIC AUDIO IN LO reference

—

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Table 4-6 Mic Audio Inputs and Mic Keys

Pin Connector

Pin Name

Description

I/O

37

J3402

PASS 2 MIC AUDIO IN HI

Passenger 2 Mic audio and ground

IN

38

J3402

PASS 2 MIC AUDIO IN LO reference

—

39

J3402

PASS 3 MIC AUDIO IN HI

Passenger 3 Mic audio and ground

IN

40

J3402

PASS 3 MIC AUDIO IN LO reference

—

41

J3402

PASS 4 MIC AUDIO IN HI

Passenger 4 Mic audio and ground

IN

42

J3402

PASS 4 MIC AUDIO IN LO reference

—

*Denotes Active Low (Ground to activate)

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4.6.2 COM Audio and Mic Keys Table 4-7 COM Audio and Mic Keys (GMA 342/345 2-COM unit only)

Pin Connector

Pin Name

12

J3401 COM 1 MIC KEY* OUT

30

J3401 COM 2 MIC KEY* OUT

9

J3401 COM 1 AUDIO IN HI

11

J3401 COM 1 MIC AUDIO OUT HI

10

J3401 COM 1 AUDIO LO

13

J3401 COM 2 AUDIO IN HI

15

J3401 COM 2 MIC AUDIO OUT HI

14

J3401 COM 2 AUDIO LO

*Denotes Active Low (grounded when active)

Description
Enables transmission on the respective transceiver unit
COM 1 Audio Input COM 1 Audio Output Ground Reference for COM 1 COM 2 Audio Input COM 2 Audio Output Ground Reference for COM 2

I/O OUT OUT
IN OUT
-IN OUT —

Table 4-8 COM Audio and Mic Keys (GMA 345 3-COM unit only)

Pin Connector

Pin Name

3

J3401 COM 3 AUDIO IN

4

J3401 COM 3 AUDIO LO

5

J3401 COM 3 MIC OUT

6

J3401 COM 3 MIC KEY* OUT

*Denotes Active Low (grounded when active)

Description
COM 3 Audio Input (GMA 345 3-COM unit only)
Ground Reference for COM 1 (GMA 345 3-COM unit only)
COM 3 Audio Output (GMA 345 3-COM unit only)
Enables transmission on the respective transceiver unit (GMA 345 3-COM unit only)

I/O IN -OUT
OUT

4.6.3 Alert Audio I/O

Table 4-9 Alert Audio I/O

Pin Connector

Pin Name

Description

I/O

31

J3401 ALERT 1 AUDIO IN HI

Alert 1 Audio Input

IN

32

J3401 ALERT 1 AUDIO IN LO

Ground Reference for Alert 1

—

15

J3402 ALERT 2 AUDIO IN HI

Alert 2 Audio Input

IN

14

J3402

ALERT 2 LO, FAILSAFE AUDIO IN LO

Ground Reference for Alert 2

29

J3401 ALERT 3 AUDIO IN HI

Alert 3 Audio Input

IN

43

J3401 ALERT 3, 4, AUX 3 AUDIO IN LO Ground Reference for Alert 3 & 4 —

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Table 4-9 Alert Audio I/O

Pin Connector

Pin Name

Description

I/O

44

J3401 ALERT 4 AUDIO IN HI

Alert 4 Audio Input

IN

4.6.4 RCVR, AUX, and NAV Audio Inputs

Table 4-10 AUX and NAV Audio Inputs

Pin Connector

Pin Name

Description

I/O

21

J3401

RCVR 3 AUDIO IN HI (AUX 1)

RCVR 3/AUX 1 Audio Input

IN

22

J3401

RCVR 3 AUDIO IN LO (AUX 1)

Ground Reference for RCVR 3/AUX 1 Input

—

7

J3401

RCVR 4 AUDIO IN HI (AUX 2)

RCVR 4/AUX 2 Audio Input

IN

8

J3401

RCVR 4 AUDIO IN LO (AUX 2)

Ground Reference for RCVR 4/AUX 2 Input

—

23

J3401

RCVR 5 AUDIO IN HI (AUX 3)

RCVR 5/AUX 3 Audio Input

IN

43

J3401

ALERT 3, 4 AUX 3 AUDIO Ground Reference for RCVR 5/AUX

IN LO

3 Audio Input

—

17

J3401 NAV 1 AUDIO IN HI

NAV 1 Audio Input

IN

18

J3401 NAV 1 AUDIO IN LO

NAV 1 Ground Reference

—

19

J3401 NAV 2 AUDIO IN HI

NAV 2 Audio Input

IN

20

J3401 NAV 2 AUDIO IN LO

NAV 2 Ground Reference

—

NOTE For GMA 342/345 2-COM units only, two buttons (AUX1 and AUX2) are used to select/ deselect the 3 AUX inputs. Pressing the AUX1 button selects/deselects the AUX 1 and AUX 3 receivers. Pressing the AUX2 button selects/deselects the AUX 2 receiver.

NOTE For the GMA 345 3-COM unit, a single AUX button is used to select all 3 AUX inputs for simultaneous monitoring.

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4.6.5 Failsafe Warning Audio
Failsafe audio is audio from another device that is heard when the GMA 342/345 is in failsafe mode (power off or unit failure) and is desired to be heard in addition to the COM audio.

Table 4-11 Failsafe Warning Audio

Pin Connector

Pin Name

Description

I/O

In the event of power loss, if wired,

29

J3402

FAILSAFE WARN AUDIO failsafe warning audio will be heard in the

IN HI

Pilot’s Left headset in addition to the

IN

COM1 Audio Input.

14

J3402

ALERT 2 LO, FAILSAFE AUDIO IN LO

Ground Reference for Failsafe Warning Audio Input

—

CAUTION During failsafe mode both FAILSAFE WARN AUDIO IN HI and COM 1 AUDIO INPUT are connected to the PILOT HEADSET LEFT OUTPUT. When in failsafe the output of the COM 1 radio and the output of the device connected to FAILSAFE WARN AUDIO IN HI will become shorted together, potentially causing damage or interference. If the FAILSAFE WARN AUDIO IN HI is used, it may be necessary to install summing resistors in series between these sources and the inputs to the audio panel to protect the outputs from damage.

4.6.6 Music Inputs
The MUSIC LO signals are not the same reference as other ground connections. The MUSIC LO signals should be used as part of a differential pair (along with the MUSIC RIGHT and MUSIC LEFT signals). If the MUSIC LO signal is tied to a ground connection, the music will contain noise, and the audio quality will be degraded.

Table 4-12 Music Inputs

Pin Connector

Pin Name

23

J3402 MUSIC 1 IN LEFT

24

J3402 MUSIC 1 IN RIGHT

25

J3402 MUSIC 1 IN LO

26

J3402 MUSIC 2 IN LEFT

27

J3402 MUSIC 2 IN RIGHT

28

J3402 MUSIC 2 IN LO

Description

I/O

Music 1 Input

IN

Differential Reference for Music 1

—

Music 2 Input

IN

Differential Reference for Music 2

—

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4.6.7 Tel Audio I/O

Table 4-13 TEL Audio/XCVR 3 I/O (GMA 342/345 2-COM unit only)

Pin Connector

Pin Name

Description

I/O

3

J3401 XCVR 3 AUDIO IN (WIRED TEL) Telephone Audio Input

IN

4

J3401 XCVR 3 AUDIO LO (WIRED TEL) Ground Reference for Telephone —

5

J3401 XCVR 3 MIC OUT HI (WIRED TEL) TEL MIC Audio Output

OUT

Table 4-14 TEL Audio I/O (GMA 345 3-COM unit only)

Pin Connector

Pin Name

25

J3401 WIRED TEL AUDIO IN HI

26

J3401 WIRED TEL AUDIO IN LO

27

J3401 WIRED TEL MIC OUT HI

28

J3401 WIRED TEL MIC OUT LO

Description
Telephone Audio Input (GMA 345 3-COM unit only)
Ground Reference for Telephone (GMA 345 3-COM unit only)
TEL MIC Audio Output (GMA 345 3-COM unit only)
Ground Reference for Telephone (GMA 345 3-COM unit only)

I/O IN -OUT —

4.6.8 Headset Outputs
Garmin recommends that stereo headsets and stereo jacks be used to fully utilize the 3D audio features of the GMA 342/345. A true mono headset will work correctly with the GMA 342/345, but only mono (left channel) audio will be heard, and 3D audio will not be available (even if enabled). The GMA 342/345 will detect the mono headset (if stereo jacks are used), and automatically switch to mono operation. 3D audio is not available with mono headsets or in installations that use mono jacks for the headsets.
In aircraft systems that are wired with stereo headset jacks, if a true mono headset is plugged into the jack, the right audio channel is shorted to ground. In this condition the GMA 342/345 will detect the right channel short, and turn off the right channel audio to the headset output to protect the GMA 342/345 headset output from driving a signal into a short (and also for internal audio routing determined by the mono headset plugged into the headset jack).
In aircraft systems that use mono headset jacks, and are wired correctly (if used, mono jacks should always use left channel audio and headset lo), 3D audio will not be available, and only left channel audio for music inputs or headset outputs will be heard

190-01878-02 Rev. 6

GMA 342/345 Installation Manual Page 4-10

.
Pin 16 31 1 3 4 2 40 41 42

Connector J3402 J3402 J3402 J3402 J3402 J3402 J3401 J3401 J3401

Table 4-15 Headset Outputs

Pin Name
PILOT HEADSET AUDIO OUT LEFT
PILOT HEADSET AUDIO OUT RIGHT
PILOT HEADSET AUDIO OUT LO
COPILOT HEADSET AUDIO OUT LEFT
COPILOT HEADSET AUDIO OUT RIGHT
COPILOT HEADSET AUDIO OUT LO
PASS HEADSET AUDIO OUT LEFT
PASS HEADSET AUDIO OUT RIGHT
PASS HEADSET AUDIO OUT LO

Description Pilot Headset Audio Output Copilot Headset Audio Output Passenger Headset Audio Output

I/O OUT OUT
-OUT OUT
-OUT OUT
—

4.6.9 Speaker Audio Out
Do not connect the LO of the speaker to the aircraft chassis. Two wires must be connected from the GMA 342/345 to the Speaker for the HI and LO signals. If speaker LO is connected to the aircraft chassis ground, the speaker will contain more noise than if connected back to the GMA 342/345 source connections.

Table 4-16 Speaker Audio Output

Pin Connector

Pin Name

43

J3402 SPEAKER AUDIO OUT LO

44

J3402 SPEAKER AUDIO OUT HI

Description
Speaker Audio Output Ground Reference
Speaker Audio Output Hi

I/O -OUT

190-01878-02 Rev. 6

GMA 342/345 Installation Manual Page 4-11

4.7 Discrete Inputs
The ICS KEYs are enabled by setting switch 1 of the DIP switch to ON. The COM Swap and Play key are always enabled.

Table 4-17 Discrete Inputs

Pin Connector

Pin Name

Description

I/O

16

J3401 PILOT ICS KEY*

Discrete Input

IN

13

J3402 PASSENGER ICS KEY*

Discrete Input

IN

20

J3402 COM SWAP*

Discrete Input

IN

22

J3402 PLAY KEY*

Discrete Input

IN

30

J3402 COPILOT ICS KEY*

Discrete Input

IN

*Denotes Active Low (Inputs: ground to activate)

4.7.1 Discrete Outputs

Table 4-18 Discrete Outputs

Pin Connector

Pin Name

24

J3401 COM ACTIVE* OUT

12

J3402 PA MUTE* OUT

19

J3402 PA MODE SELECTED*

*Denotes Active Low (Grounded when active)

Description Discrete Out Discrete Out Discrete Out

I/O OUT OUT OUT

4.8 Marker Beacon
Marker lamp outputs provide a variable DC voltage between 3V and 9V that drive incandescent lamps (>56). Lamp brightness is controlled by the photocell.
MIDDLE MARKER SENSE OUT has the same behavior as MIDDLE MARKER LAMP OUT, but with half the voltage output into the rated minimum resistance of 4.7 k.

Table 4-19 Discrete Outputs

Pin

Connector

Pin Name

1

J3401

MARKER ANTENNA IN HI

2

J3401

MARKER ANTENNA IN LO

36

J3401

INNER MARKER LAMP OUT

37

J3401

OUTER MARKER LAMP OUT

38

J3401

MIDDLE MARKER LAMP OUT

39

J3401

MIDDLE MARKER SENSE OUT

I/O IN -OUT OUT OUT OUT

190-01878-02 Rev. 6

GMA 342/345 Installation Manual Page 4-12

APPENDIX A INSTALLATION CONSIDERATIONS FOR UPGRADING FROM A GARMIN GMA 340
NOTE This appendix contains installation considerations for upgrading from a Garmin GMA 340. This is not a set of comprehensive installation instructions for installing a Garmin GMA 342/345 in place of a Garmin GMA 340. Read this manual in its entirety before starting any installation.
A.1 Mechanical Considerations
· The GMA 340 installation rack is compatible with the GMA 342/345. Refer to Section 2.2 of this manual for a list of installation materials.
· The GMA 340 connectors are compatible and may be reused.
If replacing a GMA 340 with a GMA 342/345, the GMA 340 (330-00220-25) connector backshells can be reused. However, grounding the wire shields to the GMA 342/345 will be easier with the Garmin backshells in GPN 011-02302-00. The Garmin backshells also offer higher immunity to HIRF. Current installations will not be required to change the backshell type, but would benefit from doing so.
A.2 Electrical Considerations
Figure A-1 shows the GMA 340 pins that may need to be modified to accommodate the GMA 342/345. Refer to Section 4 and Appendix C of this manual for a list of pin functions and interconnect examples.
NOTE If the GMA 340 installation to be replaced has three COM transceivers, the GMA 345 3-COM unit (see Catalog Part Numbers Table 2-1) should be used to accommodate the COM3 interface.

190-01878-02 Rev. 6

GMA 342/345 Installation Manual Page A-1

A.3 GMA 340 to GMA 342/345 Retrofit Connections

GMA 340 GMA 340 RETROFIT NOTES FOR INSTALLING GMA 342/345

J3401 P3401

COM 3 AUDIO IN HI

3

COM 3 AUDIO IN LO

4

COM 3 MIC AUDIO OUT HI

5

COM 3 MIC KEY* OUT

6

MASQ INHIBIT* IN

16

GMA 342/345 GMA 340 RETROFIT NOTES
FOR INSTALLING GMA 342/345

J3401 P3401

WIRED TEL AUDIO IN (GMA 342/345)/ COM 3 AUDIO IN (GMA 345 3-COM)

3

WIRED TEL AUDIO LO (GMA 342/345)/ COM 3 AUDIO LO (GMA 345 3-COM)

4

WIRED TEL MIC OUT (GMA 342/345)/ COM 3 MIC OUT (GMA 345 3-COM)

5

RESERVED (GMA 342/345)/ COM 3 MIC KEY* OUT (GMA 345 3-COM)

6

PILOT ICS KEY*

16

COM 3 SPKR LOAD IN HI

23

RCVR 5 AUDIO IN HI (AUX 3)

23

COM 3 SPKR LOAD IN LO

24

COM 1 SPKR LOAD IN HI

25

COM 1 SPKR LOAD IN LO

26

COM 2 SPKR LOAD IN HI

27

COM 2 SPKR LOAD IN LO

28

NO CONNECT

29

COM ACTIVE* OUT

24

RESERVED (GMA 342/345)/ WIRED TEL AUDIO IN HI (GMA 345 3-COM)

25

RESERVED (GMA 342/345)/ WIRED TEL AUDIO IN LO (GMA 345 3-COM)

26

RESERVED (GMA 342/345)/ WIRED TEL MIC OUT HI (GMA 345 3-COM)

27

RESERVED (GMA 342/345)/ WIRED TEL MIC OUT LO (GMA 345 3-COM)

28

ALERT 3 AUDIO IN HI

29

TEL RINGER AUDIO IN LO

43

ALERT 3, 4, AUX 3 AUDIO IN LO

43

TEL RINGER AUDIO IN HI

44

ALERT 4 AUDIO IN HI

44

GMA 340 GMA 340 RETROFIT NOTES FOR INSTALLING GMA 342/345
J3402 P3402

ICS MUTE INHIBIT* IN

13

ICS MUTE INHIBIT RETURN

14

HIGH GAIN MUSIC SELECT*

15

8 OHM SELECT*

17

BUTTON PRESS TONE ENABLE*

19

NO CONNECT

22

MUTE ON COM TX* IN

30

GMA 342/345 GMA 340 RETROFIT NOTES FOR INSTALLING GMA 342/345
J3402 P3402

PASSENGER ICS KEY*

13

ALERT 2 LO, FAILSAFE AUDIO IN LO

14

ALERT 2 AUDIO IN HI

15

RESERVED

17

PA MODE SELECTED*

19

PLAY KEY*

22

COPILOT ICS KEY*

30

Figure A-1 GMA 340 to GMA 342/345 Retrofit Connections

190-01878-02 Rev. 6

GMA 342/345 Installation Manual Page A-2

APPENDIX B OUTLINE AND INSTALLATION DRAWINGS

190-01878-02 Revision 6

6.30 160.0 3.1 79

.10 2.5

.200 5.08 100 CSK INSIDE RACK
(4 PLACES PER SIDE)
1.30 33.0 .60 15.2

.5 13

.44 11.1

3.7 94 6.22 157.9 8.09 205.4
4.34 110.3 4X .025 0.64
3.49 88.6 5.16 131.1

1.28 32.4 .94 23.8 .65 16.5 2X .35 8.9
Figure B-1 GMA 342/345 Outline Drawing GMA 342/345 Installation Manual Page B-1

APPENDIX B OUTLINE AND INSTALLATION DRAWINGS

190-01878-02 Revision 6

GMA 342/345 CONNECTOR KIT (ALSO USED ON GMA 35/350) 011-02302-00

GMA 342/345 BACK PLATE (ALSO USED ON GMA 240/340) SUB-ASSEMBLY 011-00678-00
Figure B-2 GMA 342/345 Installation Drawing GMA 342/345 Installation Manual Page B-2

APPENDIX B OUTLINE AND INSTALLATION DRAWINGS
OPTION 1:
STACK CUTOUT (RACK INSTALLED FROM FRONT OF AIRCRAFT PANEL)

OPTION 2:
RADIO CUTOUT (RACK INSTALLED FROM FRONT OF AIRCRAFT PANEL)

1.30 33.0

OPTION 3:
RADIO CUTOUT (RACK INSTALLED FROM BACK OF AIRCRAFT PANEL ONLY) MAXIMUM AIRCRAFT PANEL THICKNESS IS .125 INCH [3.2 mm]

1.20 30.5

190-01878-02 Revision 6

6.30 160.0 6.30 160.0 6.18 157.0

NOTES: 1. DIMENSIONS: INCH [mm] 2. IF THE FRONT LIP OF THE MOUNTING RACK IS BEHIND THE SURFACE OF THE AIRCRAFT PANEL THE UNIT CONNECTORS MAY NOT FULLY ENGAGE.
Figure B-3 GMA 342/345 Panel Cutout Drawing
GMA 342/345 Installation Manual Page B-3

APPENDIX C INTERCONNECT DRAWINGS
190-01878-02 Revision 6

GMA 342/345 INSTALLATION NOTES

1.UNLESS OTHERWISE INDICATED, ALL SHIELDS MUST BE TERMINATED AT THE GMA END ONLY. ALL SHIELDS ARE TIED TO THE SHIELD BLOCK OF THE BACKSHELL USING RING TERMINALS. USE 190-00313-09 FOR GUIDANCE FOR SHIELD TERMINATIONS.
2. UNLESS OTHERWISE NOTED, ALL STRANDED WIRE MUST CONFORM TO MIL-W-22759/16 OR EQUIVALENT. UNLESS OTHERWISE NOTED, ALL SHIELDED WIRE MUST CONFORM TO MIL-C-27500 OR EQUIVALENT.

3. UNLESS OTHERWISE NOTED, ALL WIRES ARE 22 AWG MINIMUM.

4. SYMBOL DESIGNATIONS AND CONNECTOR GUIDANCE:

WHT BLU

SHIELDED 2 CONDUCTOR

AIRCRAFT GROUND SHIELD BLOCK GROUND WIRE SPLICE
MOMENTARY CONTACT PUSH BUTTON

WHT BLU SHIELDED 3 CONDUCTOR ORN
TWISTED SHIELDED 3 CONDUCTOR SHIELD FLOATS
TWISTED SHIELDED 2 CONDUCTOR SHIELD FLOATS
TWISTED SHIELDED 3 CONDUCTOR SHIELD TERMINATED TO SHIELD BLOCK OF DSUB USING RING TERMINALS
TWISTED SHIELDED 2 CONDUCTOR SHIELD TERMINATED TO SHIELD BLOCK OF DSUB USING RING TERMINALS

TIP RING

SLEEVE NOTE 7

STEREO PLUG

TIP

SLEEVE

MONO PLUG

TIP
RING SLEEVE

STEREO PLUG INSERTED INTO JACK

TIP
RING SLEEVE

NOTE 18

MONO PLUG INSERTED INTO JACK

RING SHORTED TO SLEEVE

NOTE 5. AUDIO JACK ISOLATION DIAGRAM

AUDIO JACK

FLAT METAL WASHER

METAL NUT

SHOULDER WASHER

FLAT INSULATED WASHER
AIRCRAFT PANEL

STEREO JACK HEADSET EAR SPEAKER
TIP (LEFT CHANNEL) RING (RIGHT CHANNEL)
SLEEVE (LO)

NOTE 5 NOTE 7

JACK HEADSET MIC
TIP (*PTT) RING (MIC HI) SLEEVE (MIC LO)

NOTE 5 NOTE 7

5. ISOLATE JACK SLEEVE (MOUNTING NUT AND NUT PLATE) FROM AIRCRAFT CHASSIS. ALL HEADSET, MICROPHONE, AND MUSIC PHONE JACKS MUST BE ELECTRICALLY ISOLATED FROM GROUND. REFER TO THE FIGURE ABOVE FOR HOW THE JACK IS ISOLATED. NOT ISOLATING WILL CAUSE GROUND LOOPS AND NOISE.
6. THE CONNECTION BETWEEN PTT AND THE MIC JACK TIP IS REQUIRED IF HAND MICS WILL BE USED. DENOTES AN ACTIVE LOW SIGNAL.
7. THE HEADSET EAR SPEAKER SLEEVE DIAMETER IS 0.25 INCH AND LARGER THAN THE HEADSET MIC SLEEVE DIAMETER 0.206 INCH. 8. IF THE TRANSCIEVER HAS A SEPARATE RETURN FOR AUDIO IN AND AUDO OUT, CONNECT BOTH TO THE GMA AUDIO LO AT THE GMA. 9. DO NOT CONNECT THE SPEAKER GROUND RETURN TO THE AIRCRAFT CHASSIS. THE GROUND RETURN MUST GO TO THE GMA. 10. THE LIGHTING BUS VOLTAGE RANGE IS CONFIGURABLE FOR EITHER 14 OR 28 VOLT SYSTEMS. REFER TO INSTALL MANUAL CONFIGURATION OPTIONS. 11. GARMIN RECOMMENDS USING STEREO HEADPHONES. IF MONO JACKS ARE DESIRED, GARMIN RECOMMENDS THE USE OF THE LEFT
OUTPUT ONLY (LEAVE THE RIGHT CHANNEL UNCONNECTED). DO NOT CONNECT THE LEFT AND RIGHT CHANNELS TOGETHER.
12. THE TELEPHONE INTERFACE MAY BE WIRED TO A FIXED MOUNTED TELEPHONE SOURCE (SHOWN) OR TO A SUITABLE JACK FOR PORTABLE TELEPHONE.
13. TRANSCEIVER INTERFACES CAN ALSO BE WIRED THROUGH SUITABLE JACKS AND CABLES TO HANDHELD COMS THAT HAVE HEADSET INTERFACE CAPABILITY. THE HANDHELD’S HEADSET OUTPUT (LEFT CHANNEL ONLY IF STEREO) CONNECTS TO THE GMA’S COM AUDIO IN HI AND COM AUDIO LO PINS, THE HANDHELD’S MIC INPUT CONNECTS TO GMA’S COM MIC AUDIO OUT HI AND COM AUDIO LO PINS, AND THE HANDHELD’S PTT KEY CONNECTS TO GMA’S COM MIC KEY OUT. SEE TRANSCEIVER’S INSTRUCTION MANUAL.
14. * DENOTES ACTIVE LOW.
15. MONO ONLY HEADSET JACK CONNECTION DETAIL. 16. USE A MINIMUM 10 WATT SPEAKER.
USE 8 OHM SPEAKER FOR 28 VOLT SYSTEMS ONLY. USE 4 OHM SPEAKER FOR 14 OR 28 VOLT SYSTEMS.
17. ICS KEY INPUTS ARE ALSO COMPATIBLE WITH TWO-STAGE PTT KEYS IN WHICH THE FIRST DETENT ACTIVATES THE ICS KEY AND THE SECOND DETENT ACTIVATES THE TRANSCEIVER PTT (CREW ONLY) FOR THAT POSITION.
18. PLUGGING A MONORAIL HEADSET INTO A STEREO JACK SHORTS THE RIGHT CHANNEL OUTPUT TO GROUND. THIS WILL CAUSE EXCESS CURRENT TO BE DRAWN. THIS WILL NOT DAMAGE THE GMA, BUT IS NOT RECOMMENDED. THE GMA WILL DETECT THE SHORTED CHANNEL AND SHUT THE AUDIO TO THE SHORTED CHANNEL OFF TO PREVENT THE INTERNAL AMPLIFIER FROM DRIVING A SIGNAL INTO A SHORT.
19. THE MUSIC LO SIGNALS ARE NOT THE SAME REFERENCE AS OTHER GROUNDS. THE MUSIC LO SIGNALS ARE PART OF A DIFFERENTIAL PAIR WITH THE RIGHT AND LEFT SIGNALS. IF THE MUSIC LO SIGNAL IS TIED TO A GROUND, THE MUSIC WILL CONTAIN NOISE, AND THE AUDIO QUALITY WILL BE DEGRADED.
20. USE RG400 FOR MARKER BEACON COAXIAL CABLE. THE RF MATING CONNECTION FOR THE ANTENNA (BNC, TNC, N) WILL DEPEND ON THE MARKER BEACON ANTENNA USED FOR DSUB COAXIAL CABLE INSTALLATION GUIDELINES REFER TO MARKER INSTALLATION SECTION OF INSTALL MANUAL. AVOID SHARP CORNERS AND ROUTE AWAY FROM HIGH CURRENT WIRING AND ANY TRANSMITTER CABLES.

Figure C-1 Notes for Example Interconnect Drawings
GMA 342/345 Installation Manual Page C-1

APPENDIX C INTERCONNECT DRAWINGS
GMA 342/345
J3401 P3401

COM 1 AUDIO IN HI

9

COM 1 AUDIO LO

10

S

SEE NOTE 8

COM 1 MIC AUDIO OUT HI

11

S

COM 1 MIC KEY* OUT

12

COM1 Transceiver
SEE NOTE 13

COM 2 AUDIO IN HI

13

COM 2 AUDIO LO

14

S

SEE NOTE 8

COM 2 MIC AUDIO OUT HI COM 2 MIC KEY* OUT

15
S
30

TEL AUDIO IN HI TEL AUDIO LO
TEL MIC AUDIO OUT HI

3

4

S

SEE NOTE 8

5

S

NAV 1 AUDIO IN HI NAV 1 AUDIO IN LO NAV 2 AUDIO IN HI NAV 2 AUDIO IN LO
AUX 1 AUDIO IN HI AUX 1 AUDIO IN LO AUX 2 AUDIO IN HI AUX 2 AUDIO IN LO
ALERT 1 AUDIO IN HI ALERT 1 AUDIO IN LO
ALERT 3 AUDIO IN HI ALERT 3, 4, AUX 3 AUDIO LO
ALERT 4 AUDIO IN HI ALERT 3, 4, AUX 3 AUDIO LO
AUX 3 AUDIO IN HI ALERT 3, 4, AUX 3 AUDIO LO
PILOT MIC AUDIO IN LO PILOT MIC AUDIO IN HI
PILOT MIC KEY IN
PASS HEADSET LO PASS HEADSET RIGHT
PASS HEADSET LEFT
INNER MARKER LAMP OUT OUTER MARKER LAMP OUT MIDDLE MARKER LAMP OUT
MIDDLE MARKER SENSE OUT SHIELD BLOCK GROUND
PILOT ICS KEY IN
COM ACTIVE* OUT

17 18
S
19 20
S
21 22
S
7 8
S
31 32
S
29 43
S
44
S
23
S
35 33
S
34
42 41 40
S
36 37 38
39
S
16
24

SEE NOTE 14

COM2 Transceiver
SEE NOTE 13
TEL SYSTEM
(OR JACK TO MATCH DESIRED PHONE)
SEE NOTE 12
NAV1 Radio
NAV2 Radio AUX 1 Source
AUX 2 Source
Alert 1 Audio
Alert 3 Audio

GMA 345 3-COM (011-03520-20/ -21) ONLY COM 3 AND TEL WIRING DIFFERENCES

COM 3 AUDIO IN HI COM 3 AUDIO LO
COM 3 MIC AUDIO OUT HI COM 3 MIC KEY* OUT
TEl AUDIO IN HI TEL AUDIO LO
TEL MIC AUDIO OUT HI TEL MIC AUDIO OUT LO

3 4

S

SEE NOTE 8

5
S
6

25

26

S

SEE NOTE 8

27

28
S

COM3 Transceiver
SEE NOTE 13
TEL SYSTEM
(OR JACK TO MATCH DESIRED PHONE)
SEE NOTE 12

NOTE: Pressing the AUX1 button selects/ deselects the AUX1 and AUX3 receivers

Alert 4 Audio

AUX 3 Source

SEE NOTE 5,6

PILOT PTT

(up to 4 jacks, wired in parallel)
SEE NOTE 5

ALTERNATE PTT CONNECTION
PILOT PTT
SEE NOTES 5, 6

EXT INDICATOR
FLIGHT CONTROL SYSTEM

Inhibit Input of Applicable Audio Source

MARKER BEACON ANTENNA

MARKER ANTENNA HIGH

1

MARKER ANTENNA LO

2

SEE NOTE 20

190-01878-02 Revision 6

NO CONNECT PINS 6,25,26,27,28

Figure C-2 J3401 Connector Example Interconnect Drawing
GMA 342/345 Installation Manual Page C-2

APPENDIX C INTERCONNECT DRAWINGS
190-01878-02 Revision 6

GMA 342/345
J3402 P3402

PILOT HEADSET LO PILOT HEADSET RIGHT
PILOT HEADSET LEFT
COPILOT HEADSET LO COPILOT HEADSET RIGHT
COPILOT HEADSET LEFT
COPILOT MIC AUDIO IN LO COPILOT MIC AUDIO IN HI
COPILOT MIC KEY IN
PASS 1 MIC AUDIO IN LO PASS 1 MIC AUDIO IN HI
PASS 2 MIC AUDIO IN LO PASS 2 MIC AUDIO IN HI
PASS 3 MIC AUDIO IN LO PASS 3 MIC AUDIO IN HI
PASS 4 MIC AUDIIO IN LO PASS 4 MIC AUDIIO IN HI
MUSIC 1 IN LO MUSIC 1 IN RIGHT
MUSIC1 IN LEFT
MUSIC 2 IN LO MUSIC 2 IN RIGHT
MUSIC 2 IN LEFT
SPEAKER AUDIIO OUT HI SPEAKER AUDIO OUT LO
ALERT 2 AUDIO IN HI ALERT 2, FAILSAFE AUDIO LO
FAILSAFE WARN AUDIO IN HI
PA MUTE OUT PA MODE SELECTED* OUT

1 31 16
S
2 4 3
S
34 32
S
33
36 35
S
38 37
S
40 39
S
42 41
S
25 24 23
S
28 27 26
S
44 43
S
15 14
S
29
S
12 19

LIGHTING BUS 14V HI/28V HI

7

LIGHTING BUS 14V HI/28V LO

6

LIGHTING BUS 14V LO/28V LO

5

SEE NOTE 5

SEE NOTE 5

SEE NOTE 5,6

SEE NOTE 5 COPILOT PTT

ALTERNATE PTT CONNECTION
COPILOT PTT

SEE NOTE 5

SEE NOTES 5, 6

SEE NOTE 5

SEE NOTE 5
SEE NOTE 5
SEE NOTE 5 SEE NOTE 19
SEE NOTE 5 SEE NOTE 19 Cabin Speaker SEE NOTE 9,16
Alert 2 Audio
Failsafe Audio
Mute Trigger to EXT PA

SEE NOTE 10 REFER TO THE LIGHTING BUS WIRING DIAGRAM FOR WIRING OPTIONS.

PASSENGER ICS KEY IN COM SWAP IN PLAY KEY IN
COPILOT ICS KEY IN
AIRCRAFT POWER AIRCRAFT POWER
POWER GROUND POWER GROUND
GROUND
RS-232 IN RS-232 OUT

13
20 SEE NOTE 14
22
30

USE 5 AMP BREAKER

8

9

5A

Aircraft Power Bus

10

USE 22 AWG FOR POWER AND GROUND

11

21 SPARE GROUND CAN BE USED FOR ANY GROUND RETURN EXCEPT POWER OR MUSIC. DO NOT USE FOR POWER OR MUSIC GROUND.
17 18

Figure C-3 J3402 Connector Example Interconnect Drawing
GMA 342/345 Installation Manual Page C-3

APPENDIX C INTERCONNECT DRAWINGS
GMA 342/345
J3402 P3402

OR

14 VOLT LIGHTING BUS

LIGHTING BUS 14V HI/28V HI

7

LIGHTING BUS 14V HI/28V LO

6

TO 14 VOLT LIGHTING BUS HI

LIGHTING BUS 14V LO/28V LO

5

TO 14 VOLT LIGHTING BUS LO

LIGHTING BUS 14V HI/28V HI

7

LIGHTING BUS 14V HI/28V LO

6

LIGHTING BUS 14V LO/28V LO

5

28 VOLT LIGHTING BUS
TO 28 VOLT LIGHTING BUS HI
TO 28 VOLT LIGHTING BUS LO

190-01878-02 Revision 6

IF NEITHER OF THE ABOVE LIGHTING BUS CONFIGURATIONS ARE WIRED, THE UNIT WILL DEFAULT TO USE THE DISPLAY PHOTOCELL FOR LIGHTING CONTROL
Figure C-4 Lighting Bus Example Interconnect Drawing GMA 342/345 Installation Manual Page C-4

APPENDIX C INTERCONNECT DRAWINGS

GMA 342/345
MONO AUDIO CONNECTIONS
J3402 P3402

MONO CONNECTIONS

PILOT HEADSET LEFT PILOT HEADSET LO
PILOT HEADSET RIGHT

16 1
S
31 NC

COPILOT HEADSET LEFT COPILOT HEADSET LO
COPILOT HEADSET RIGHT

3 2
S
4 NC

MUSIC 1 IN LEFT MUSIC 1 IN LO
MUSIC 1 IN RIGHT

23
25
S
24 NC

190-01878-02 Revision 6

MUSIC 2 IN LEFT MUSIC 2 IN LO
MUSIC 2 IN RIGHT

26 28
S
27 NC

PILOT HEADSET JACK NOTE 5,15
COPILOT HEADSET JACK NOTE 5,15
MONO AUDIO SOURCE MONO AUDIO OUT HI MONO AUDIO OUT LO
MONO AUDIO SOURCE MONO AUDIO OUT HI MONO AUDIO OUT LO
Figure C-5 Mono Audio Example Interconnect Drawing GMA 342/345 Installation Manual Page C-5

APPENDIX C INTERCONNECT DRAWINGS
GMA 342/345
J3401 P3401

PASSENGER HEADSET PARALLEL WIRING
UP TO 4 JACKS

PASS HEADSET LO

42

PASS HEADSET RIGHT

41

PASS HEADSET LEFT

40

NOTE 5

190-01878-02 Revision 6

Figure C-6 Four Passenger Headset Wiring Example Interconnect Drawing
GMA 342/345 Installation Manual Page C-6

APPENDIX C INTERCONNECT DRAWINGS

TO UNIT CONNECTOR
TO UNIT BACKSHELL USING SHIELD BLOCK. TERMINATE USING RING TERMINAL.

1/4 INCH HEADSET JACK

LEFT HEADSET AUDIO

H

RIGHT HEADSET AUDIO

S

HEADSET AUDIO LO

MICROPHONE JACK

PTT

M

MICROPHONE HI

I

MICROPHONE LOW

C

BLK

*DENOTES ACTIVE LOW. BLK

GMA AUDIO PANEL
PTT*
MIC HI MIC LO

NOTE FOR HAND MICS: THE CONNECTION BETWEEN PTT AND THE MIC JACK TIP IS REQUIRED IF HAND MICS WILL BE USED. *DENOTES ACTIVE LOW. SEE BELOW FOR EXAMPLE.

PTT M I C

LEMO JACK PINOUT 6 PIN LEMO JACK

RED BLK WHT BLU WHT WHT/BLU

1. +VIN 2. GND 3. HEADSET L 4. HEADSET R 5. MIC HI 6. MIC LO

AIRCRAFT GROUND SHIELD BLOCK GROUND
WIRE SPLICE
MOMENTARY CONTACT PUSH BUTTON

LEMO SHIELD WIRES CONNECT TO GMA SHIELD BLOCK USING RING CONNECTORS

LEMO MONO CONNECTION DIRECT TO AUDIO PANEL

GMA AUDIO PANEL

LEFT HS

RIGHT HS

NC

MIC HI MIC LO

PTT* PTT

ALL SPLICES FROM LEMO JACK OCCUR AT GMA END OF HARNESS

1/2 AMP BREAKER

+10-32 VDC

RED

BLK

WHT

BLU BLK
WHT

WHT/BLU BLK

LEMO SHIELD WIRES CONNECT TO GMA SHIELD BLOCK USING RING CONNECTORS

LEMO STEREO CONNECTION DIRECT TO AUDIO PANEL

GMA AUDIO PANEL
LEFT HS RIGHT HS
MIC HI MIC LO
PTT*

1/2 AMP BREAKER

+10-32 VDC

RED

BLK

WHT

BLU BLK
WHT

WHT/BLU BLK

PTT

190-01878-02 Revision 6

6 PIN LEMO JACK
1. +VIN 2. GND 3. HEADSET L 4. HEADSET R 5. MIC HI 6. MIC LO

CONNECT LEMO GROUND TO THE SHIELD BLOCK OF THE AUDIO PANEL

LEMO SHIELD WIRES CONNECT TO GMA SHIELD BLOCK USING RING CONNECTORS

LEMO MONO CONNECTION TO EXISTING JACKS

GMA AUDIO PANEL HEADSET LO

LEFT HS

RIGHT HS

NC

MIC HI

MIC LO

PTT*

PTT
ALL SPLICES FROM LEMO JACK OCCUR AT GMA END OF HARNESS

1/2 AMP BREAKER

+10-32 VDC

RED

BLK

WHT

BLU BLK
WHT

WHT/BLU BLK

H S
6 PIN LEMO JACK
1. +VIN 2. GND 3. HEADSET L 4. HEADSET R 5. MIC HI 6. MIC LO
M I C

CONNECT LEMO GROUND TO THE SHIELD BLOCK OF THE AUDIO PANEL

6 PIN LEMO JACK
1. +VIN 2. GND 3. HEADSET L 4. HEADSET R 5. MIC HI 6. MIC LO

CONNECT LEMO GROUND TO THE SHIELD BLOCK OF THE AUDIO PANEL

LEMO STEREO CONNECTION TO EXISTING JACKS

LEMO SHIELD WIRES

CONNECT TO GMA SHIELD

BLOCK USING RING

H

CONNECTORS

S

GMA AUDIO PANEL HEADSET LO

LEFT HS RIGHT HS
MIC HI MIC LO

PTT*

PTT
ALL SPLICES FROM LEMO JACK OCCUR AT GMA END OF HARNESS

1/2 AMP BREAKER

+10-32 VDC

RED

BLK

WHT

BLU BLK
WHT

WHT/BLU BLK

6 PIN LEMO JACK
1. +VIN 2. GND 3. HEADSET L 4. HEADSET R 5. MIC HI 6. MIC LO
M I C

CONNECT LEMO GROUND TO THE SHIELD BLOCK OF THE AUDIO PANEL

Figure C-7 LEMO Connector Example Interconnect Drawing

GMA 342/345 Installation Manual Page C-7

APPENDIX C INTERCONNECT DRAWINGS

GMA 342/345 J3401 (NOT APPLICABLE TO 3-COM UNITS)

15

14

13

12

11

10

9

8

7

6

5

4

3

2

1

COM 2 MIC COM 2 AUDIO COM 2 AUDIO

AUDIO OUT HI

LO

IN HI

COM 1 MIC KEY* OUT

COM 1 MIC COM 1 AUDIO COM 1 AUDIO

AUDIO OUT HI

LO

IN HI

RCVR 4 AUDIO IN LO
(AUX 2)

RCVR 4 AUDIO IN HI
(AUX 2)

RESERVED

XCVR 3 MIC OUT HI
(WIRED TEL)

XCVR 3 AUDIO LO (WIRED TEL)

XCVR 3 AUDIO IN (WIRED TEL)

MARKER ANTENNA LO

MARKER ANTENNA HI

30

29

28

27

26

25

24

23

22

21

20

19

18

17

16

COM 2 MIC KEY* OUT

ALERT 3 AUDIO IN HI

RESERVED

RESERVED

RESERVED

RESERVED

DISCRETE C OUT* (COM ACTIVE OUT)

RCVR 5 AUDIO IN HI
(AUX 3)

RCVR 3 AUDIO IN LO
(AUX 1)

RCVR 3 AUDIO IN HI
(AUX 1)

NAV 2 AUDIO IN LO

NAV 2 AUDIO IN HI

NAV 1 AUDIO IN LO

NAV 1 AUDIO IN HI

DISCRETE 1 INPUT* (PILOT
ICS KEY)

44
ALERT 4 AUDIO IN HI

43
ALERT 3, 4, AUX 3 AUDIO
IN LO

42
PASS HEADSET AUDIO OUT
LO

41
PASS HEADSET AUDIO OUT
RIGHT

40
PASS HEADSET AUDIO OUT
LEFT

39
MIDDLE MARKER SENSE OUT

38

37

36

35

MIDDLE MARKER LAMP OUT

OUTER MARKER LAMP
OUT

INNER MARKER LAMP OUT

PILOT MIC AUDIO IN LO

34
PILOT MIC KEY* IN

33

32

31

PILOT MIC

ALERT 1

ALERT 1

AUDIO IN HI AUDIO IN LO AUDIO IN HI

GMA 342/345 J3402 (NOT APPLICABLE TO 3-COM UNITS)

15

14

13

12

11

10

9

8

7

6

5

4

3

2

1

ALERT 2 AUDIO IN HI

ALERT 2 LO, DISCRETE 3 DISCRETE D FAILSAFE INPUT (PASS OUT (PA
AUDIO IN LO ICS KEY) MUTE OUT)

POWER GROUND

POWER GROUND

AIRCRAFT POWER

AIRCRAFT POWER

LIGHTING BUS 14V HI/28V HI

LIGHTING BUS 14V HI/28V LO

LIGHTING BUS 14V LO/28V LO

COPILOT HEADSET AUDIO OUT
RIGHT

COPILOT HEADSET AUDIO OUT
LEFT

COPILOT HEADSET AUDIO OUT
LO

PILOT HEADSET AUDIO OUT
LO

30

29

28

27

26

25

24

23

22

21

20

19

18

17

16

DISCRETE 6 INPUT*
(COPIILOT ICS KEY)

FAILSAFE WARN AUDIO
IN HI

MUSIC 2 IN LO

MUSIC 2 IN RIGHT

MUSIC 2 IN LEFT

MUSIC 1 IN LO

MUSIC 1 IN RIGHT

MUSIC 1 IN LEFT

DISCRETE 5 INPUT* (PLAY
KEY)

GROUND

DISCRETE 4 INPUT* (COM
SWAP)

DISCRETE F OUT* (PA MODE
SELECTED)

RS-232 OUT

RS-232 IN

PILOT HEADSET AUDIO OUT
LEFT

44

43

42

41

40

39

38

37

36

35

34

33

32

31

SPEAKER AUDIO OUT HI

SPEAKER AUDIO OUT
LO

PASS 4 MIC AUDIO IN LO

PASS 4 MIC AUDIO IN HI

PASS 3 MIC AUDIO IN LO

PASS 3 MIC AUDIO IN HI

PASS 2 MIC AUDIO IN LO

PASS 2 MIC AUDIO IN HI

PASS 1 MIC AUDIO IN LO

PASS 1 MIC AUDIO IN HI

COPILOT MIC COPILOT MIC COPILOT MIC

AUDIO IN LO

KEY* IN

AUDIO IN HI

PILOT HEADSET AUDIO OUT
RIGHT

190-01878-02 Revision 6

Figure C-8 J3401 & J3402 Connector Layout Drawing (not applicable to 3-COM Units)
GMA 342/345 Installation Manual Page C-8

APPENDIX C INTERCONNECT DRAWINGS

GMA 345 J3401 (3-COM UNIT ONLY)

15

14

13

12

11

10

9

8

7

6

5

4

3

2

1

COM 2 MIC COM 2 AUDIO COM 2 AUDIO

AUDIO OUT HI

LO

IN HI

COM 1 MIC KEY* OUT

COM 1 MIC COM 1 AUDIO COM 1 AUDIO

AUDIO OUT HI

LO

IN HI

RCVR 4 AUDIO IN LO
(AUX 2)

RCVR 4 AUDIO IN HI
(AUX 2)

COM 3 MIC KEY* OUT

COM 3 MIC OUT

COM 3 AUDIO LO

COM 3 AUDIO IN

MARKER

MARKER

ANTENNA LO ANTENNA HI

30

29

28

27

26

25

24

23

22

21

20

19

18

17

16

COM 2 MIC KEY* OUT

ALERT 3 AUDIO IN HI

WIRED TEL MIC OUT LO

WIRED TEL MIC OUT HI

WIRED TEL AUDIO IN LO

WIRED TEL AUDIO IN HI

DISCRETE C OUT* (COM ACTIVE OUT)

RCVR 5 AUDIO IN HI
(AUX 3)

RCVR 3 AUDIO IN LO
(AUX 1)

RCVR 3 AUDIO IN HI
(AUX 1)

NAV 2 AUDIO IN LO

NAV 2 AUDIO IN HI

NAV 1 AUDIO IN LO

NAV 1 AUDIO IN HI

DISCRETE 1 INPUT* (PILOT
ICS KEY)

44
ALERT 4 AUDIO IN HI

43
ALERT 3, 4, AUX 3 AUDIO
IN LO

42
PASS HEADSET AUDIO OUT
LO

41
PASS HEADSET AUDIO OUT
RIGHT

40
PASS HEADSET AUDIO OUT
LEFT

39
MIDDLE MARKER SENSE OUT

38

37

36

35

MIDDLE MARKER LAMP OUT

OUTER MARKER LAMP
OUT

INNER MARKER LAMP OUT

PILOT MIC AUDIO IN LO

34
PILOT MIC KEY* IN

33

32

31

PILOT MIC

ALERT 1

ALERT 1

AUDIO IN HI AUDIO IN LO AUDIO IN HI

GMA 345 J3402 (3-COM UNIT ONLY)

15

14

13

12

11

10

9

8

7

6

5

4

3

2

1

ALERT 2 AUDIO IN HI

ALERT 2 LO, DISCRETE 3 DISCRETE D FAILSAFE INPUT (PASS OUT (PA
AUDIO IN LO ICS KEY) MUTE OUT)

POWER GROUND

POWER GROUND

AIRCRAFT POWER

AIRCRAFT POWER

LIGHTING BUS 14V HI/28V HI

LIGHTING BUS 14V HI/28V LO

LIGHTING BUS 14V LO/28V LO

COPILOT HEADSET AUDIO OUT
RIGHT

COPILOT HEADSET AUDIO OUT
LEFT

COPILOT HEADSET AUDIO OUT
LO

PILOT HEADSET AUDIO OUT
LO

30

29

28

27

26

25

24

23

22

21

20

19

18

17

16

DISCRETE 6 INPUT*
(COPIILOT ICS KEY)

FAILSAFE WARN AUDIO
IN HI

MUSIC 2 IN LO

MUSIC 2 IN RIGHT

MUSIC 2 IN LEFT

MUSIC 1 IN LO

MUSIC 1 IN RIGHT

MUSIC 1 IN LEFT

DISCRETE 5 INPUT* (PLAY
KEY)

GROUND

DISCRETE 4 INPUT* (COM
SWAP)

DISCRETE F OUT* (PA MODE
SELECTED)

RS-232 OUT

RS-232 IN

PILOT HEADSET AUDIO OUT
LEFT

44

43

42

41

40

39

38

37

36

35

34

33

32

31

SPEAKER AUDIO OUT HI

SPEAKER AUDIO OUT
LO

PASS 4 MIC AUDIO IN LO

PASS 4 MIC AUDIO IN HI

PASS 3 MIC AUDIO IN LO

PASS 3 MIC AUDIO IN HI

PASS 2 MIC AUDIO IN LO

PASS 2 MIC AUDIO IN HI

PASS 1 MIC AUDIO IN LO

PASS 1 MIC AUDIO IN HI

COPILOT MIC COPILOT MIC COPILOT MIC

AUDIO IN LO

KEY* IN

AUDIO IN HI

PILOT HEADSET AUDIO OUT
RIGHT

190-01878-02 Revision 6

Figure C-9 J3401 & J3402 Connector Layout Drawing for 3-COM units
GMA 342/345 Installation Manual Page C-9

References

• flyGarmin - Home
• Garmin International | Home
• Prop 65 | Garmin

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