Garmin GTX 23 ES, Installation Manual

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Page 2-2 GTX 23 Installation Manual
Revision A 190-00906-01
2.3.2 Antenna Location Considerations
The antenna should be installed in accordance with AC 43.12-2A Chapter 3.
Figure 2-1 Antenna Installation Considerations
a. The antenna (Garmin P/N 010-10160-00 or equivalent) 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 shadow (block)
the signal between the transponder antenna and ATC radar on TCAS.
b. The antenna should be mounted vertically on the bottom of the aircraft (Figure 2-1).
c. Antenna Separation: DME and TCAS receive signals in the same frequency range that
aviation transponders transmit at, so their antennas should be separated from the transponder
antenna by as much as feasible. Six feet of separation is a guideline. Radar altimeters (should
one be installed on an aircraft with a GTX 23) also have some potential to receive interference
from a transponder (the transponders’ fourth harmaonic), so it is good practice to separate
transponder and radar altimeter antennas by as much as practical also. Avoid mounting the
antenna within three feet of the ADF sense antenna or any other communication antenna.
d. To prevent RF interference, the antenna must be physically mounted a minimum distance of
three feet from the GTX 23.
If the antenna is being installed on a composite aircraft, sufficient ground plane
material must be added. Conductive wire mesh, radials, or thin aluminum sheets
embedded in the composite material provide the proper ground plane allowing the
antenna gain pattern to be maximized for optimum transponder performance.
NOTE
Mount Antenna on
Bottom of Aircraft