Installation Procedure; Wiring Harness Installation; Backshell Assemblies; Coax Cable Installation - Garmin GTX 3x5 Series Installation Manual

4 INSTALLATION PROCEDURE

4.1 Wiring Harness Installation

All electrical connections, except for the antenna(s) and shield grounds, are made through the D-sub
connectors on the rear of the unit. The shield grounds are terminated to the connector backshells.
The rear connector pinout and descriptions for the interface connections are included in section 5. See
appendix ?? for wiring diagrams.
The required connectors and associated hardware are included in the connector kit. See table 3-1 for
applicable connector kit.

4.2 Backshell Assemblies

Include an illustration of the D-sub, backshell assemblies, and ground terminations.

4.3 Coax Cable Installation

NOTE
For some antennas (e.g., GPS), verify the length is set for the desired cable loss before
trimming. Some antennas have minimum cable loss specifications, which may require a
cable that is longer than the physical run in the aircraft.
Follow the steps below for installation of the coaxial cables:
1. Route the coaxial cable to the radio rack location keeping in mind the recommendations of
section 3.8. Secure the cable in accordance with AC 43.13-1B chapter 11, section 11.
2. Trim the coaxial cable to the desired length and install the coaxial connectors per the
manufacturer's instructions.

4.4 Connector Backshell Assembly

After harness and coax cable installation, secure the connectors to the connector backplate using the
supplied screws.

4.5 Equipment Mounting - Panel Mount Units

4.5.1 Rack Installation
NOTE
If the aircraft structure is modified, refer to the applicable installation data.
See section ?? for drawing dimensions needed to prepare the mounting holes for the GTX 3x5 unit. The
GTX 3x5 mounting rack may also be used as a template for drilling the mounting holes.
1. Figure ?? shows the outline dimensions for the rack. Install the rack in a rectangular hole (or
appropriate gap between units) in the instrument panel. The lower front lip of the rack should be
flush with, or extend slightly beyond, the finished aircraft panel.
NOTE
If the front lip of the mounting rack is behind the surface of the aircraft panel, the GTX 3x5
connectors may not fully engage. See figure ?? for more information. Ensure that no screw
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GTX 3x5 TSO Installation Manual
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