Garmin GXM 53 Installation Instructions - Page 2

Testing the Mounting Location 1 Temporarily secure the antenna in the preferred mounting location and test it for correct operation. 2 If you experience interference with other electronics, move the antenna to a different location, and test it again. 3 Repeat steps 1-2 until you observe full or acceptable signal strength. 4 Permanently mount the antenna. Surface Mounting the Antenna NOTICE If you are mounting the bracket on fiberglass with screws, it is recommended to use a countersink bit to drill a clearance counterbore through only the top gel-coat layer. This will help to avoid cracking in the gel-coat layer when the screws are tightened. Stainless-steel screws may bind when screwed into fiberglass and overtightened. It is recommended to apply an anti-seize lubricant on the screws before installing them. Before you permanently mount the antenna, you must test the mounting location for correct operation (Antenna Mounting Considerations, page 1). 1 Using the surface-mount bracket as your mounting À template, mark the three pilot-hole locations and trace the cable-hole in the center of the bracket. 8 Verify the large gasket is in place on the bottom of the à antenna, place the antenna on the surface-mount bracket, and twist it clockwise to lock it in place. 9 Secure the antenna to the mounting bracket with the included M3 screw . Ä 10Route the cable away from sources of electronic interference. Mounting the Antenna with the Cable Routed Through the Pole Before you permanently mount the antenna, you must test the mounting location for correct operation ( (Antenna Mounting Considerations, page 1)). 1 Position a standard 1 in. OD, 14 threads per inch, pipe- threaded pole (not included) in the selected location, and mark the approximate center of the pole. 2 Drill a hole using a 19 mm (3/4 in.) drill bit for the cable to pass through. 3 Fasten the pole to the boat. 4 Thread the pole-mount adapter onto the pole. Do not overtighten the adapter. 5 Route the cable through the pole and connect it to the antenna. 6 Place the antenna on the pole-mount adapter and twist it clockwise to lock it in place. 7 Secure the antenna to the adapter with the included M3 set screw . À 2 Set the surface-mount bracket aside. Do not drill through the bracket. 3 Drill the three 3.2 mm (1/8 in.) pilot holes. 4 Drill the 19 mm (3/4 in.) cable hole in the center. 5 Place the seal pad on the bottom of the surface-mount Á bracket, aligning the screw holes. 6 Use the included M4 screws to secure the surface-mount bracket to the mounting surface. 7 Route the cable through the center hole and connect it to  the antenna. 8 With the antenna installed on the pole mount, fill the vertical cable slot with a marine sealant (optional). Á 9 Route the cable away from sources of electronic interference. Mounting the Antenna with the Cable Routed Outside the Pole Before you permanently mount the antenna, you must test the mounting location for correct operation ( (Antenna Mounting Considerations, page 1)). 1 Route the cable through the pole-mount adapter , and À place the cable in the vertical slot along the base of the Á pole-mount adapter. 2