Antenna Considerations; 3.12.1 Transponder Antenna - Garmin GTX 3X5 Installation Manual

3.12

Antenna Considerations

Mounting location considerations for the antenna(s) are provided in this section. The recommended
antenna locations are shown in figure 3-3.

3.12.1 Transponder Antenna

NOTE
Ground planes must be considered for installations on composite aircraft. Conductive
wire mesh, radials, or thin aluminum sheets embedded in the composite material supply
the ground plane to maximize the antenna pattern (gain). This can improve transponder
performance.
The antenna mounting must use the aircraft manufacturer's type certificated antenna location and style.
The antenna must be installed in accordance with manufacturer instructions and/or AC 43.12-2A
Chapter 3.
Transponder antenna considerations help the installer to select the best location for the antenna. The
antenna should:
• Be attached away from major protrusions, such as engines, nacelles, propellers, and antenna masts.
• Be as far as practical from landing gear doors, access doors, or other openings that could affect its
radiation pattern.
• Be vertically attached on the bottom of the aircraft.
• Not be attached within three feet of the ADF sense antenna or any other communication antenna.
• Not be attached within six feet of a DME antenna.
• Be attached a minimum of three feet from the GTX 3X5 to prevent RF interference.
190-01499-02
Rev. 4
GTX 3X5 Transponder TSO Installation Manual
Page 3-21