Page 2-2
GMA 1347D Installation Manual
Revision C
190-00303-21
2.3 Installation
Considerations
The GMA 1347D interfaces with the G1000 system, and 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 1347D.
2.3.1 Marker Beacon Antenna Installation
2.3.1.1 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.
2.3.1.2
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.
2.3.1.3
Marker Beacon Antenna Cable Installation
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)
