Under-deck
mounting bracket

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

1.Position a standard 1 in. OD pipe-threaded-pole marine mount (14 threads per inch—not included) in the preferred location, and mark the approximate center of the pole.

2.Drill a hole using a 3/4 in. (19 mm) drill bit for the cable to pass through.

3.Fasten the pipe-threaded pole marine mount to the boat.

4.Thread the pole-mount adapter onto the pole. Do not overtighten the adapter.

5.Route the NMEA 2000/audio cable through the pole and connect it to the GXM 51 antenna.

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

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

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

9.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).

Under-deck-mounting the GXM 51 Antenna

The GXM 51 can be mounted under a fiberglass surface with the adhesive pads attached to the under-deck mounting bracket. The GXM 51 will not acquire satellite signals through metal— you can only use the under-deck mount under a fiberglass surface.

1.Determine the location on the fiberglass surface where you want to mount the GXM 51.

2.Place the adhesive pads on the under-deck mounting bracket.

3.Place the GXM 51 in the under-deck mounting bracket.

4.Adhere the under-deck mounting bracket to the mounting surface.

Adhesive

pads

Mounting

surface

GXM 51 antenna

5.Secure the under-deck mount to the mounting surface with

screws. Use extreme care to ensure that the screws do not penetrate the upper surface of the deck.

6.Connect the NMEA 2000/audio cable to the GXM 51.

7.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 step 3 below).



GXM 51 Installation Instructions