190-01115-01
G3X/G3X Touch Installation Manual - GPS/XM Antenna Installation
Rev. AC
Page 22-1
22 GPS/XM ANTENNA INSTALLATION
This section contains general information as well as installation information for GPS, GPS/WAAS, and
XM antennas. Use this section to mount the antenna(s).
In an installation with multiple GDU 37X/4XX units, each GDU can be configured to use its own internal
GPS receiver, or to receive GPS data transmitted by another GDU. A minimum of one GPS antenna is
required for installations using more than one GDU 37X/4XX unit, as the GDU will “share” the GPS
information with all GDU units. Additional GPS antennas may be used for redundancy, but are not
required. See
(for GDU 37X systems) or
(for GDU 4XX systems) for
further information.
NOTE
The GPS 20A can only be used with GA 35, GA 36, or GA 37 antennas.
NOTE
GA 35, GA 36 and GA 37 antennas cannot be used with GDU 37X/4XX units.
NOTE
When a GPS 20A (and connected GPS/WAAS antenna) is installed, it can be used as the
sole GPS for the system, however it is recommended to install a GPS antenna on at least
one of the GDU 37X/4XX units for redundancy.
22.1 Non-Garmin Antennas
Table 22-1 lists non-Garmin antennas currently supported by the GDU 37X/4XX. For non-Garmin
antennas, follow the manufacturer’s installation instructions. It is the installer’s responsibility to ensure
that their choice of antenna meets FAA standards according to the specific installation.
NOTE
The GPS antenna should provide a gain of 16 to 25 dB. The GDU 37X/4XX supplies
power to the antenna at 4.5 V–5V with a maximum current of 50 mA.
Table 22-1 Supported Non-Garmin Antennas
Model
Mount Style
Conn
Type
Antenna
Type
Mfr
Antenna Part
Number
Garmin Order
Number
Comant
2480-201
VHF/GPS*
Screw Mount,
Teardrop
Footprint
BNC
TNC
VHF
COM,
GPS
Comant
CI 2480-201
N/A
Comant
420-10 XM
only Antenna
Screw Mount,
ARINC 743
Footprint
TNC
XM
Comant
CI 420-10
N/A
*The GPS antenna connector is TNC type. The VHF COM antenna connector is BNC type.