Garmin 330, 330D User Manual

GTXTM 330, GTXTM 330D
TRANSPONDER
INSTALLATION
MANUAL

Garmin Ltd. or its subsidiaries

190-00207-02 Revision G

October 2004

£

© Copyright 2002 – 2004

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.

Garmin International, Inc.

1200 E. 151

st

Street

Olathe, KS 66062 USA

Telephone: [phone]

Aviation Dealer Technical Support Line (Toll Free): [phone]

www.garmin.com

Garmin (Europe) Ltd.

Unit 5, The Quadrangle, Abbey Park Industrial Estate

Romsey, SO51 9DL, U.K.

Telephone: [phone]

RECORD OF REVISIONS

Revision Revision Date Description ECO #

A
B
C
D
E
F
G

10/24/02 Initial Release 19401

5/1/03 Upgrade to SW 3.03 20932
6/3/03 Reverse Pins 47 and 53 on J3301 21261

8/4/03 Added Figure 4-9, 330/327 w/Dual Display 21954
10/22/03 Added TIS/TCAD combo and SW connector 22929
03/26/04 Upgrade to SW 3.05 25218
10/05/04 Upgrade to SW 3.06 27691

Page A GTX 330 Installation Manual
Revision G 190-00207-02

This manual reflects the operation of software version 3.06. Some differences in operation may be
observed when comparing the information in this manual to earlier or later software versions.

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. A violation of the EAR may be subject to a penalty of up
to 10 years imprisonment and a fine of up to $1,000,000 under Section 2410 of the Export Administration
Act of 1979. Include this notice with any reproduced portion of this document.

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

Throughout this document references made to GTX 330 shall equally apply to the
GTX 330D except where specifically noted.

GTX 330 Installation Manual Page i
190-00207-02 Revision G

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Page ii GTX 330 Installation Manual
Revision G 190-00207-02

TABLE OF CONTENTS

PARAGRAPH PAGE

1 GENERAL DESCRIPTION..............................................................................................................1-1

1.1 Introduction........................................................................................................................................1-1

1.2 Equipment Description ......................................................................................................................1-1

1.3 TIS System Capabilities.....................................................................................................................1-2

1.4 Mutual Suppression Pulses ................................................................................................................1-2

1.5 Interface Summary............................................................................................................................. 1-3

1.6 Technical Specifications .................................................................................................................... 1-4

1.7 Installation Approval .........................................................................................................................1-5

1.8 Aircraft Station Licensing Requirements...........................................................................................1-5

1.9 Limited Warranty............................................................................................................................... 1-6

2 INSTALLATION OVERVIEW ........................................................................................................2-1

2.1 Introduction........................................................................................................................................2-1

2.2 Installation Materials .........................................................................................................................2-1

2.3 Installation Considerations ................................................................................................................2-2

2.4 Antenna Installation...........................................................................................................................2-2

2.5 Cabling and Wiring............................................................................................................................2-4

2.6 Installation Approval Considerations for Pressurized Aircraft .........................................................2-5

2.7 Cooling Air ........................................................................................................................................2-6

2.8 GTX 330 Installation .........................................................................................................................2-6

3 INSTALLATION PROCEDURE...................................................................................................... 3-1

3.1 Unpacking Unit.................................................................................................................................. 3-1

3.2 Electrical Connections .......................................................................................................................3-1

3.3 Circuit Breaker Placard...................................................................................................................... 3-2

3.4 Post Installation Checkout .................................................................................................................3-2

4 SYSTEM INTERCONNECTS..........................................................................................................4-1

4.1 Pin Function List................................................................................................................................4-1

4.2 Power and Lighting Function ............................................................................................................4-3

4.3 Temperature Inputs............................................................................................................................4-3

4.4 Altitude Functions .............................................................................................................................4-4

4.5 Discrete Functions .............................................................................................................................4-6

4.6 Serial Data Electrical Characteristics.................................................................................................4-8

GTX 330 Installation Manual Page iii
190-00207-02 Revision G

PARAGRAPH PAGE

5 POST INSTALLATION CONFIGURATION AND CHECKOUT PROCEDURE ......................... 5-1

5.1 Operation ...........................................................................................................................................5-1

5.2 Configuration Pages...........................................................................................................................5-5

APPENDIX A CERTIFICATION DOCUMENTS

A.1 STC................................................................................................................................................... A-1

A.2 Continued Airworthiness .................................................................................................................. A-3

A.3 Environmental Qualification Forms, GTX 330 M o d e S Transponder ........................................ A-5

APPENDIX B ASSEMBLY AND INSTALLATION DRAWINGS

APPENDIX C INTERCONNECT DRAWINGS

Page iv GTX 330 Installation Manual
Revision G 190-00207-02

LIST OF ILLUSTRATIONS

FIGURE PAGE

2-1 Antenna Installation Considerations..................................................................................................2-1

2-2 GTX 330 Unit Rack...........................................................................................................................2-7

4-1 Rear Connector, J3301.......................................................................................................................4-1

4-2 Dual GTX 330, Single Encoder, Serial Input Connections ...............................................................4-5

4-3 GTX 330, Software Update Connections ..........................................................................................4-9

5-1 GTX 330 Front Panel.........................................................................................................................5-1

A-1 GTX 330 Environmental Qualification Form................................................................................... A-6

B-1 GTX 330 Outline Drawing ............................................................................................................... B-1

B-2 GTX 330 Connector/Rack Assembly Drawing ................................................................................ B-3

B-3 GTX 330 Recommended Panel Cutout Dimensions......................................................................... B-5

C-1 GTX 330 to 400/500 Series Units, Typical Interconnect Wiring Diagram ...................................... C-1

C-2 GTX 330 to CNX80/ GNS 480, Typical Interconnect Wiring Diagram .......................................... C-3

C-3 GTX 330 to CNX80/GNS 480 and MFD, Simplified Interconnect Wiring Diagram ...................... C-5

C-4 GTX 330 Interconnect Wiring Diagram, Discrete And Audio Connections .................................... C-7

C-5 GTX 330 Interconnect Wiring Diagram, Serial Devices Connections ............................................. C-9

C-6 GTX 330 Interconnect Wiring Diagram, Altitude and Temperature Connections ......................... C-11

C-7 Dual Transponder Interconnect Wiring Diagram, Dual Display Connections ............................... C-13

C-8 GTX 330 Interconnect Wiring Diagram, Aircraft With TIS and TCAD/TCAS............................. C-17

C-9 Dual TXP Interconnect Wiring Diagram, Encoding Altitude Connections ................................... C-19

LIST OF TABLES

TABLE PAGE

3-1 Pin Contact Part Numbers..................................................................................................................3-1

3-2 Recommended Crimp Tools ..............................................................................................................3-1

4-1 P3301 Pin Assignments .....................................................................................................................4-1

4-2 Aircraft Power Pin Assignments........................................................................................................4-3

4-3 Aircraft Lighting Pin Assignments .................................................................................................... 4-3

4-4 Temperature Probe Pin Assignments................................................................................................. 4-3

4-5 Encoded Altitude Pin Assignments ...................................................................................................4-4

4-6 Discrete Outputs Pin Assignments.....................................................................................................4-6

4-7 Discrete Inputs Pin Assignments .......................................................................................................4-7

4-8 RS-232 Pin Assignments ...................................................................................................................4-8

4-9 ARINC 429 Pin Assignments .......................................................................................................... 4-10

GTX 330 Installation Manual Page v
190-00207-02 Revision G

GTX 330 HARDWARE MOD LEVEL HISTORY

The following table identifies hardware modification (Mod) Levels for the GTX 330 and GTX 330D
Mode S Transponders. Mod Levels are listed with the associated service bulletin number, service
bulletin date, and the purpose of the modification. The table is current at the time of publication of this
manual (see date on front cover) and is subject to change without notice. Authorized Garmin Sales and
Service Centers are encouraged to access the most up-to-date bulletin and advisory information on the
Garmin Dealer Resource web site at www.garmin.com using their Garmin-provided user name and
password.

MOD

LEVEL

1 0311 2-6-04 GTX 330D Only. Switch/Diplexer Assembly

SERVICE

BULLETIN

NUMBER

SERVICE

BULLETIN

DATE

PURPOSE OF MODIFICATION

reworked to prevent +200 volt supply line from
shorting to the chassis.

Page vi GTX 330 Installation Manual
Revision G 190-00207-02

1. GENERAL DESCRIPTION

1.1 Introduction

This manual presents the mechanical, and electrical installation requirements for the GTX 330 Mode S
Transponder and GTX 330D Diversity Mode S Transponder. Throughout this manual, the term GTX 330
applies to both transponders unless otherwise stated. After installation of the GTX 330, FAA Form 337
must be completed by an appropriately certificated agency to return the aircraft to service.

1.2 Equipment Description

The Garmin GTX 330 is a panel mounted Non-Diversity Mode S Transponder while the GTX 330D
is a Diversity Mode S Transponder. The GTX 330D employs two antennas, one intended to be
mounted on the top and the other on the bottom of the aircraft. The design meets RTCA/DO-181C
and EUROCAE ED-73A specifications.

The GTX 330 transponder is a radio transmitter and receiver that operates on radar frequencies, receiving
ground radar or TCAS interrogations at 1030 MHz and transmitting a coded response of pulses to ground­based radar on a frequency of 1090 MHz. The GTX 330 is equipped with IDENT capability that
activates the Special Position Identification (SPI) pulse for 18 seconds.

The GTX 330 replies to ATCRBS Mode A, Mode C and Mode S All-Call interrogation. Mode A
replies consist of any one of 4,096 codes, which differ in the position and number of pulses
transmitted. Mode C replies include framing pulses and encoded altitude. Mode S interrogations are
selective. The Mode S transponders can respond to a single directed interrogation from the ground
station or another aircraft.

The GTX 330 is a Level 2 transponder, providing downlink of aircraft information. Ground stations can
interrogate Mode S Transponders individually using a 24-bit ICAO Mode S address, which is unique to
the particular aircraft. In addition, ground stations may interrogate a GTX 330 for its Transponder data
capability and the aircraft's Flight ID, which may be the registration number or other call sign. The
GTX 330 makes the maximum airspeed capability (set via configuration pages, see Section 5) available to
TCAS systems on-board nearby aircraft to aid in the determination of TCAS advisories.

In addition to displaying the code, reply symbol and mode of operation, the GTX 330 screen displays
pressure altitude, density altitude, temperature, and timer functions, depending on equipment connections
and configuration selection. The unit also features an altitude monitor, TIS traffic advisories and flight
timers. A voice or tone audio output announces altitude deviation, TIS traffic advisory and count down
timer expiration.

The GTX 330 features multiple transmit/receive ARINC 429 and RS-232 data ports. The unit
concentrates data from three ARINC 429 inputs, gray code, RS-232 input data and discrete inputs to the
high-speed ARINC 429 output bus used by display systems such as the Garmin 400 Series/500 Series
units.

The GTX 330 is configured with all key controls. The layout of the front panel keys and displays
segregates the transponder’s primary functions from the secondary functions. The unit can be configured
so the aircraft avionics master bus can turn the unit on.

Provision is made for unit software upgrade by means of RS-232 data through rear connector pins. If an
optional connector is placed in the aircraft, transponder removal and reinstallation for SW upgrade is not
required. The software can be changed while the unit is still mounted inside the aircraft.

GTX 330 Installation Manual Page 1-1
190-00207-02 Revision G

CAUTION

The GTX 330 lens is coated with a special anti-reflective coating which
is very sensitive to skin oils, waxes and abrasive cleaners. CLEANERS
CONTAINING AMMONIA WILL HARM THE ANTI-REFLECTIVE
COATING. It is very important to clean the lens using a clean, lint free
cloth and an eyeglass lens cleaner that is specified as safe for anti­reflective coatings.

1.3 TIS System Capabilities

The GTX 330 also provides uplink information such as Traffic Information Service (TIS). TIS is a
ground-based service providing relative location of all ATCRBS Mode A and Mode C transponder
equipped aircraft within a specified service volume. The TIS ground sensor uses real time track reports to
generate traffic notification. TIS provides a graphic display of traffic advisory information in the cockpit
for non-TCAS equipped aircraft.

Advisory traffic information is available to aircraft equipped with a Mode S data link such as the Garmin
GTX 330 transponder. Advisory traffic information may be displayed on a Garmin 400/500 Series unit.

The GTX 330 unit can also be incorporated in installations with other compatible control/display units
such as the Garmin CNX80/GNS 480 and MX20 Multifunction Display (MFD).

Surveillance data includes all transponder equipped aircraft within the coverage volume. Aircraft without
an operating transponder are invisible to TIS. TIS displays traffic within seven nautical miles from 3000
feet below to 3500 feet above the requesting aircraft. The pilot sees the location, relative direction and
altitude of other aircraft.

1.4 Mutual Suppression Pulses

Other equipment on board the aircraft may transmit in the same frequency band as the transponder,
such as DME or another transponder. Mutual suppression is a synchronous pulse that is sent to the
other equipment to suppress transmission of a competing transmitter for the duration of the pulse train
transmission. The transponder transmission may be suppressed by an external source and other
equipment on board may be suppressed by the transponder. This feature is designed to limit mutual
interference.

Page 1-2 GTX 330 Installation Manual
Revision G 190-00207-02

1.5 Interface Summary

The GTX 330 provides the following interface connections via the rear connector:

• Ten (10) encoding altimeter inputs.

• External IDENT input.

• External STBY input (useful for dual transponder installations).

• External suppression pulse input.

• Switched power output of up to 1.5 amps (for digital altitude encoder power).

• Aircraft power input (11 to 33 volts).

• Aircraft dimming bus input voltage.

• Aircraft master switch turn-on option.

• Serial altitude or GPS groundspeed input.

• Serial altitude input. (Reduces wire count vs. parallel wire gray code altimeter interface.)

• Software update input.

• Supports Comm-A and Comm-B protocol.

• Temperature, Altitude Hold and Density Altitude.

• Digitally recorded voice and discrete warning annunciator activated by Altitude Hold when

limits are exceeded.

• Diversity: GTX 330 is available with or without the diversity feature.

The GTX 330 supports the following list of Binary Data Selector (BDS) registers:

• BDS (0,0) Air Initiated Comm-B (AICB)

• BDS (1,0) Data Link Capability Report

• BDS (1,7) Common Usage Ground Initiated Comm-B (GICB) Capability Report

• BDS (1,8) Mode S Specific Services GICB Capability Report

• BDS (1,9) Mode S Specific Services GICB Capability Report

• BDS (1,D) Mode S Specific Services Protocols (MSP) Capability Report

• BDS (2,0) Aircraft Identification

GTX 330 Installation Manual Page 1-3
190-00207-02 Revision G

BDS register information is presented for the installation agency to understand the functionality of the
GTX 330, and make a determination that the unit complies with the requirements of their civil aviation
authorities. No further wiring or configuration programming is required for the unit.

Note that BDS (3,0) is only required for transponders compatible with ACAS/TCAS II. The GTX 330
does not support BDS (3,0).

1.6 Technical Specifications

The following table presents general environmental specifications. For detailed specifications, see the
Environmental Qualification form in Appendix A.

1.6.1 Electrical Specifications

Specification Characteristic

TSO, JTSO; GTX 330 TSO-C112*, JTSO-2C112a.

TSO, JTSO; GTX 330D TSO-C112*, JTSO-2C112a.

TSO ENV CAT Refer to Appendix A

FCC Authorization Emission Designator 12M0M1D

Applicable Documents RTCA DO-160D, DO-181C, EuroCAE ED-73A

Unit Software RTCA DO-178B Level D

Temperature Range

Power Requirements 11.0 to 33.0 Vdc; Power Input: 22 watts typical, 45

Humidity

Altitude 55,000 Feet

Transmitter Frequency 1090 MHz ±1 MHz

Transmitter Power 125 watts minimum, 250 watts nominal.

Receiver Frequency 1030 MHz

Receiver Sensitivity -74 dBm nominal for 90% replies

Mode A Capability 4096 Identification Codes

Mode C Altitude Capability 100 Foot Increments from -1000 to 62,700 feet.

Mode S Altitude Capability 25 Foot Increments from -1000 to 50,175 feet with

-45°C to +70°C (continuous operation)

watts maximum

95% @ +50°C for 6 hours; 85% @ +38°C for 16 hours;
Tested to Category A in DO-160D

suitable serial data altitude. 100 Foot Increments from

-1000 to 62,700 feet.

Mode S Capability Selective Identification Codes, Aircraft Type

External Suppression Input

Audio Output

* Note: Refer to Paragraph 1.6.3 Configurations Available, for TSO class.

Page 1-4 GTX 330 Installation Manual
Revision G 190-00207-02

Low ≤ 0.5 V; High ≥ 8 V

4.04 Vrms to 7.85 Vrms into a 500

 load

1.6.2 Physical Characteristics

Specification Characteristic

Bezel Height 1.65 inches (42 mm)

Bezel Width 6.25 inches (159 mm)

Rack Height (Dimple to Dimple) 1.68 inches (43 mm)

Rack Width 6.30 inches (160 mm)

Depth Behind Panel with Connectors
(measured from face of aircraft panel to
rear of connector backshells)

GTX 330/GTX 330D Unit Weight 3.4 lbs. (1.5 kg)

GTX 330/GTX 330D Rack Weight
(Installed with rack and connectors)

11.25 inches (286 mm)

4.2 lbs. (1.9 kg)

1.7 Installation Approval

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. For GTX 330 TSO compliance and STC,
see Appendix A. For antenna TSO compliance, refer to antenna manufacturer’s literature.

1.8 Aircraft Station Licensing Requirements

The Telecommunications Act of 1996, effective February 8, 1996, provides the FCC discretion to
eliminate radio station license requirements for aircraft and ships. The GTX 330 installation must comply
with current transmitter licensing requirements. To find out the specific details on whether a particular
installation is exempt from licensing, please visit the FCC web site http://wireless.fcc.gov/aviation.

If an aircraft license is required, make application for a license on FCC form 404, Application for Aircraft
Radio Station License. The FCC also has a fax-on-demand service to provide forms by fax. The
GTX 330 owner accepts all responsibility for obtaining the proper licensing before using the transponder.

CAUTION

The UHF transmitter in this equipment is guaranteed to meet federal communications
commission acceptance over the operating temperature range. Modifications not
expressly approved by Garmin could invalidate the license and make it unlawful to
operate the equipment.

GTX 330 Installation Manual Page 1-5
190-00207-02 Revision G

1.9 Limited Warranty

This Garmin product is warranted to be free from defects in materials or workmanship for two years from
the date of purchase. Within this period, Garmin will at its sole option, repair or replace any components
that fail in normal use. Such repairs or replacement will be made at no charge to the customer for parts or
labor, provided that the customer shall be responsible for any transportation cost. This warranty does not
cover failures due to abuse, misuse, accident or unauthorized alteration or repairs.

THE WARRANTIES AND REMEDIES CONTAINED HEREIN ARE EXCLUSIVE AND IN LIEU OF
ALL OTHER WARRANTIES EXPRESS OR IMPLIED OR STATUTORY, INCLUDING ANY
LIABILITY ARISING UNDER ANY WARRANTY OF MERCHANTABILITY OR FITNESS FOR A
PARTICULAR PURPOSE, STATUTORY OR OTHERWISE. THIS WARRANTY GIVES YOU
SPECIFIC LEGAL RIGHTS, WHICH MAY VARY FROM STATE TO STATE.

IN NO EVENT SHALL GARMIN BE LIABLE FOR ANY INCIDENTAL, SPECIAL, INDIRECT OR
CONSEQUENTIAL DAMAGES, WHETHER RESULTING FROM THE USE, MISUSE, OR
INABILITY TO USE THIS PRODUCT OR FROM DEFECTS IN THE PRODUCT. Some states do not
allow the exclusion of incidental or consequential damages, so the above limitations may not apply to
you.

Garmin retains the exclusive right to repair or replace the unit or software or offer a full refund of the
purchase price at its sole discretion. SUCH REMEDY SHALL BE YOUR SOLE AND EXCLUSIVE
REMEDY FOR ANY BREACH OF WARRANTY.

To obtain warranty service, contact your local Garmin Authorized Service Center. For assistance in
locating a Service Center near you, call Garmin Customer Service at one of the numbers shown below.

Products sold through online auctions are not eligible for rebates or other special offers from Garmin.
Online auction confirmations are not accepted for warranty verification. To obtain warranty service, an
original or copy of the sales receipt from the original retailer is required. Garmin will not replace missing
components from any package purchased through an online auction.

Garmin International, Inc. Garmin (Europe) Ltd.
1200 East 151

st

Street Unit 5, The Quadrangle, Abbey Park Industrial Estate
Olathe, Kansas 66062, U.S.A. Romsey, SO51 9DL, U.K.
Phone: [phone] Phone: [phone]
FAX: [phone] FAX: [phone]

Page 1-6 GTX 330 Installation Manual
Revision G 190-00207-02

2 INSTALLATION OVERVIEW

2.1 Introduction

This section provides hardware equipment information for installing the GTX 330 Mode S Transponder,
related hardware and optional accessories. Installation of the GTX 330 should follow the data detailed in
this manual. Cabling is fabricated by the installing agency to fit each particular aircraft. The installation
should follow the guidance of FAA AC 43.13-1B and AC 43.13-2A where applicable.

2.2 Installation Materials

The GTX 330 is available under the following part numbers:

2.2.1 Configurations Available

Model

Catalog

Part

Number

GTX 330 010-00230-00 011-00455-00 No Black No 2A1 121 010

GTX 330 010-00230-01 011-00455-00 No Black Yes 2A1 121 010

GTX 330 010-00230-20 011-00455-20 No Gray No 2A1 121 010

GTX 330 010-00230-21 011-00455-20 No Gray Yes 2A1 121 010

GTX 330D 010-00293-00 011-00455-10 Yes Black No 2A1 121 011

GTX 330D 010-00293-01 011-00455-10 Yes Black Yes 2A1 121 011

GTX 330D 010-00293-20 011-00455-30 Yes Gray No 2A1 121 011

GTX 330D 010-00293-21 011-00455-30 Yes Gray Yes 2A1 121 011

* Note: Documentation includes pilot’s guide and warranty registration card.

Unit Part

Number

Diversity Front

Panel
Color

Install

Kit/Docs*

TSO Class

2.2.2 Equipment Available

Item Garmin P/N

Sub Assy, Connector Kit, GTX 330 011-00583-00
SMP, Install Rack, GTX 330 115-00294-00
Sub Assy, Backplate, GTX 330 011-00582-00

(For use with GTX 330)

Sub Assy, Backplate, GTX 330D 011-00582-01

(For use with GTX 330D)

Garmin GTX 330 Antenna kit*

010-10160-00

(two required for diversity)

* Note: A transponder antenna approved to TSO C66( ) or C74( ) that has been installed to meet the

requirements of this manual may be approved for use with the GTX 330.

GTX 330 Installation Manual Page 2-1
190-00207-02 Revision G

2.2.3 Additional Equipment Required

• Cables - The installer will supply all system cables including circuit breakers. Cable
requirements and fabrication are detailed in Section 3 of this manual.

• Hardware - #6-32 x 100° Flat Head SS Screw [(MS24693, AN507R or other approved fastener)
(6 ea.)] and #6-32 Self-Locking Nut [MS21042 or other approved fastener (6 ea.)]. Hardware
required to mount the installation rack is not provided.

• Encoding Altitude Digitizer - Use encoding altimeter manufacturer’s instructions, install
according to FAA AC 43.13-1B and AC 43.13-2A. The Garmin GAE 43 (Garmin
P/N 013-00066-00) can provide altitude data in either serial or parallel gray code format.

2.3 Installation Considerations

The GTX 330 can interface with equipment including altimeters, Air Data Computer (ADC) and a
temperature probe. RS-232 and ARINC 429 provide a serial communication path between interfacing
equipment. Fabrication of a wiring harness is required.

Optional available discrete line interfaces are described in Section 4.5.2, Discrete Inputs, and shown in
installation diagrams provided in Appendix C.

2.4 Antenna Installation

2.4.1 Location Considerations

Antenna mounting should utilize the aircraft manufactures Type Certificated antenna location and style of
antenna. If a second (diversity) antenna is installed in the aircraft, considerations for its mounting should
be made as outlined in Figure 2-1. The antenna installation should be installed in accordance with AC

43.12-2A Chapter 3. Note that penetration of the pressure vessel on the pressurized aircraft requires
additional data not contained in this manual. (See Section 2.5)

Page 2-2 GTX 330 Installation Manual
Revision G 190-00207-02

Figure 2-1. Antenna Installation Considerations

A. The antenna(s) (Garmin P/N 010-10160-00) should be mounted away from major

protrusions, such as engine(s), propeller(s), and antenna masts. It should also be as far as
practical from landing gear doors, access doors, or other openings that could effect its
radiation pattern.

B. The main antenna should be mounted vertically on the bottom of the aircraft. The optional

second (diversity) antenna should be mounted vertically on top of the aircraft. Horizontal
separation must be no more than 7.6 meters (25 feet).

C. Avoid mounting the antenna within three feet of the ADF sense antenna or any other

communication antenna and six feet from the DME antenna.

D. To prevent RF interference, the antenna must be physically mounted a minimum distance of

three feet from the GTX 330.

NOTE

If the antenna is being installed on a composite aircraft, ground planes must be
considered. 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 transponder performance.

2.4.2 Antenna Installation

Install the antenna according to the antenna manufacturer’s instructions and FAA AC 43.13-1B and
AC 43.13-2A.

GTX 330 Installation Manual Page 2-3
190-00207-02 Revision G

2.5 Cabling and Wiring

Use MIL-W-22759/16 or other approved wire, AWG #24 or larger wire for all connections. The standard
pin contacts supplied in the connector kit are compatible with up to AWG #22 wire. In cases where some
installations have more than one unit sharing a common circuit breaker, sizing and wire gauge is based on
aircraft circuit breaker layout, length of wiring, current draw of units, and internal unit protection
characteristics. Do not attempt to combine more than one unit on the same circuit breaker unless it is
specified on aircraft manufacturer approved drawings.

In some cases, a larger gauge wire such as AWG #18 or #16 may be needed for power connections. If
using #16 or #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 or to ground.

Ensure that routing of the wiring does not come in contact with sources of heat, RF or EMI interference.
Check that there is ample space for the cabling and mating connectors. Avoid sharp bends in cabling and
routing near aircraft control cables.

The following table lists examples of the recommended antenna cable vendors and the type of cable to be
used for specific lengths of cable. Any cable meeting specifications is acceptable for the installation.

The following table is for reference only, and lists some suitable cable types, along with the maximum
length based on an assumed loss figure of 0.2 dB per connector. Any 50 , double shielded coaxial cable
assembly that meets airworthiness requirements and the 1.5 dB maximum loss figure (including
connectors) may be used.

Max. Length

(feet – [m])

Insertion loss

(dB/100ft)

ECS Type MIL-C-17 Type RG Type

6' 1.3" [1.86m] 18.0 M17/128-RG400 RG-400

7' 7.3" [2.32m] 14.45 3C142B

9' 2.0" [2.79m] 12.00 M17/112-RG304 RG-304

12' 6.0" [3.81m] 8.80 311601 M17/127-RG393 RG-393

15' 5.4" [4.71m] 7.12 311501

19' 9.4" [6.03m] 5.56 311201

30' 3.6" [9.24m] 3.63 310801

Supplier
Information

Vendor: Electronic
Cable Specialists

5300 W. Franklin
Drive
Franklin, WI 53132
Tel: [phone]
414-421-5300

See current issue
of Qualified
Products List
QPL-17.

RG types are
obsolete and
are shown for
reference only;
replaced by
M17 type
numbers.

Fax: [phone]

www.ecsdirect.com

Page 2-4 GTX 330 Installation Manual
Revision G 190-00207-02

2.5.1 Cable Routing Considerations

When routing cables, observe the following precautions:

• All cable routing should be kept as short and as direct as practical.

• Avoid sharp bends.

• Avoid routing cables near power sources (e.g., 400 Hz generators, trim motors, etc.) or near

power for fluorescent lighting.

• Avoid routing antenna cables near ADF antenna cable (allow at least a 12-inch separation).

2.6 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
subject 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. Obtain FAA Advisory Circular AC-183C and select (and contact) a DER from the roster of
individuals identified thereunder.

5. Contact an aviation industry organization such as the Aircraft Electronics Association and request
their assistance.

GTX 330 Installation Manual Page 2-5
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2.7 Cooling Air

The GTX 330 meets all applicable TSO requirements without forced air cooling. The application of
forced air cooling to the rear air nozzle of the GTX 330 is highly recommended to provide beneficial
cooling to the unit.

The GTX 330 was designed to handle a constant interrogation of 450 Pulse Repetition Frequency (PRF)
per second, with short periods of 1200 PRF. Rate limit is set at 1200 PRF. A typical radar site would
interrogate the transponder once every 5 to 10 seconds for approximately 100 milliseconds at a 400 PRF
rate. In very high traffic areas with multiple ground stations and TCAS traffic it is possible to have long
term PRF rates above 450 PRF.

2.8 GTX 330 Installation

2.8.1 Viewing Angle

Ensure that any mounting location will offer sufficient viewing angle. The display has been proven to
meet specifications when seen within the following envelope of viewing positions:

Direction Pilot’s Viewing Angle

Left and Right ±45°
From Top 30°
From Bottom 10°

Page 2-6 GTX 330 Installation Manual
Revision G 190-00207-02

2.8.2 Mechanical Installation

NOTE

Avoid installing the unit near heat sources. If this is not possible, insure
that additional cooling is provided. Allow adequate space for installation
of cables and connectors. The installer will supply and fabricate all of
the cables. All wiring must be in accordance with FAA AC 43.13-1B
and AC 43.13-2A.

1. Assemble the connector/rack kit according to Figure B-2. Install the rack assembly according to
the dimensions given in Figure B-1 and paragraph 1.6.2, Physical Characteristics. Mounting
brackets are not supplied due to the wide range of mounting configurations available. Suitable
mounting brackets may be fabricated from sheet metal or angle stock. To insure a sturdy mount,
rear support for the unit must be provided.

2. Looking at the bottom of the transponder, make sure the front lobe of the locking mechanism is in
a vertical position. This can be accomplished by using a 3/32” Allen wrench through the face
plate.

3. Slide the unit into the rack until the front lobe of the unit touches the rack.

4. Turn the Allen wrench clockwise until unit is secured in the rack. Continue turning until tight.
Do not overtighten the screw.

5. To remove the unit from the rack, turn the 3/32” Allen wrench counterclockwise until it
disengages from the rack.

Figure 2-2. GTX 330 Unit Rack (115-00294-00)

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Page 2-8 GTX 330 Installation Manual
Revision G 190-00207-02

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, except for the antenna(s) and shield ground, are made through a single, 62 pin
D-subminiature connector (see Figure 4-1). The card-edge connector may be used to terminate shield
grounds to the GTX 330 back plate. Table 4-1 lists the electrical connections of all input and output
signals. See Appendix C for interconnect wiring diagrams and cable requirements for each signal.
Required connector and associated hardware are supplied in the connector kit (P/N 011-00583-00).

CAUTION

Check wiring connections for errors before inserting the GTX 330 into
the rack. Incorrect wiring could cause internal component damage.

Table 3-1. Pin Contact Part Numbers

Manufacturer

Garmin P/N 336-00044-01 336-00044-00 336-00044-02 336-00021-00
Military P/N N/A N/A N/A M39029/58-360
AMP N/A N/A N/A 204370-2
Positronic N/A N/A N/A MC8522D
ITT Cannon N/A N/A N/A 030-2042-000

16 AWG

(Power Only)

62 pin D-Subminiature connector (P3301)

18 AWG

(Power Only)

20 AWG 22-28 AWG

Table 3-2. Recommended Crimp Tools

Manufacturer Hand

Crimping Tool

Military P/N M22520/2-01 N/A M81969/1-04 M22520/2-09 M81969/1-04
Positronic 9507 9502-11 M81969/1-04 9502-3 M81969/1-04
ITT Cannon 995-0001-584 N/A N/A 995-0001-

AMP 601966-1 N/A 91067-1 601966-6 91067-1
Daniels AFM8 K774 M81969/1-04 K42 M81969/1-04
Astro 615717 N/A M81969/1-04 615725 M81969/1-04

Positioner Insertion/

16, 18 & 20 AWG 22-28 AWG

Positioner Insertion/

Extraction Tool

(note 2)

N/A

739

Extraction

Tool

GTX 330 Installation Manual Page 3-1
190-00207-02 Revision G

NOTES

1. Non-Garmin part numbers shown are not maintained by Garmin and consequently are subject
to change without notice.

2. Extracting the #16, #18 and #20 contact 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 Circuit Breaker Placard

Install a Circuit Breaker Placard labeled Transponder or Transponder 1, Transponder 2 as appropriate as
indicated in AC 43.13-2A, paragraph 27c(4).

3.4 Post Installation Checkout

After the installation is complete, refer to Section 5 for system configuration.

Verify proper operation of the transponder by testing in accordance with Appendix F to 14 CFR Part 43 –
ATC Transponder Tests and Inspections.

Page 3-2 GTX 330 Installation Manual
Revision G 190-00207-02