Surface-mounting the GXM 51 Antenna

1.Use the surface-mount bracket as your mounting template.

•Use a pencil to mark the three screw locations on the surface and to trace the cable hole in the center of the bracket.

•Set the surface-mount bracket aside. Do not drill through the surface-mount bracket.

2.Drill three 1/8 in. (3 mm) pilot holes.

Note: If you are mounting the GXM 51 on fiberglass, it is recommended to use a countersink bit to drill a clearance counterbore through the top gelcoat layer (but no deeper). This will help to avoid cracking in the gelcoat layer when the screws are tightened.

3. Use a 1 in. (25 mm) hole saw to cut the cable hole in the center.

4.Use the included M4 screws to attach the surface-mount bracket to the mounting surface.

5.Route the NMEA 2000/audio cable through the 1 in. (25 mm) cable hole and connect it to the GXM 51.

6.Make sure the large gasket is in place on the bottom of the GXM 51 antenna, place the antenna on the surface-mount bracket ➊, and twist it clockwise to lock it in place ➋.

7.Secure the antenna to the mounting bracket with the included M3 set screw ➌.

 

➋

 

GXM 51

➊

antenna

➌

 

Surface-mount

Rubber

bracket

gasket

Mounting

surface

8.Route the NMEA 2000/audio cable

away from sources of electronic interference, and connect it to your NMEA 2000 network and to the audio input of your stereo receiver (see page 5).

Pole Mounting the GXM 51 Antenna

With the pole-mount adapter attached to the GXM 51, you can install the GXM 51 on a standard 1 in. OD pipe-threaded-pole marine mount (14 threads per inch—not included). You can route the NMEA 2000/audio cable either through the pole or outside the pole.

To mount the GXM 51 with the cable routed outside the pole:

1.Route the NMEA 2000/audio cable through the pole-mount adapter, and place the cable in the vertical slot along the base of the pole-mount adapter.

2.Thread the pole-mount adapter onto a standard 1 in. OD pipe-threaded-pole marine mount (14 threads per inch—not included). Do not overtighten the adapter.

3.Connect the NMEA 2000/audio cable to the GXM 51 antenna.

4.Place the GXM 51 antenna on the pole-mount adapter ➊ and twist it clockwise to lock it in place ➋.

5.Secure the antenna to the adapter with the included M3 set screw ➌.

6.(Optional) With the GXM 51 installed on the pole mount, fill the remaining gap in the vertical cable slot with a marine sealant (not included).

7.Attach the marine mount to the boat if it is not already attached.

8.Route the NMEA 2000/audio cable away from sources of electronic interference, and connect it to your NMEA 2000 network and to the audio input of your stereo receiver (see page 5).

➋

➌

GXM 51 antenna

➊

Pole-mount adapter

Vertical cable slot

GXM 51 Installation Instructions