GXM 51 Installation Instructions
3
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
.
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
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
•
•
GXM 51
antenna
Surface-mount
bracket
Mounting
surface
➊
➋
➌
Rubber
gasket
GXM 51
antenna
Surface-mount
bracket
Mounting
surface
➊
➋
➌
Rubber
gasket
GXM 51
antenna
Pole-mount
adapter
Vertical cable
slot
➊
➋
➌
GXM 51
antenna
Pole-mount
adapter
Vertical cable
slot
➊
➋
➌