GA 38 - TV Antenna GARMIN - Free user manual and instructions

Product Type	External GPS antenna for marine plotter
Brand	Garmin
Model	GA 38
Dimensions (diameter × height)	91,6 × 49.5 mm
Weight	201 g
Housing material	Impact-resistant plastic alloy, hermetically sealed
Water resistance	IPX7 (submersible up to 1 m for 30 min)
Temperature range	-30 °C to 80 °C
Safe distance to compass	114 mm
Connector	BNC (for ANTENNA or EXT GPS port)
Mounting methods	Flat on deck, on swivel (internal or external cable), under deck (fiberglass only)
Plotter compatibility	Garmin plotters equipped with an ANTENNA or EXT GPS port with BNC connector
Main functions	GPS reception to improve positioning accuracy and reliability
Installation instructions	See detailed manual: drilling, fixing, signal test before final installation
Safety precautions	Wear safety glasses, hearing protection and dust mask when drilling/cutting; avoid electromagnetic interference (engine, radar, VHF)
Maintenance	External cleaning with soft cloth and soapy water; check seals periodically
Spare parts	Flat deck mount bracket, swivel adapter, sealing gasket, M4 and M3 screws
Warranty	Standard Garmin warranty (see manufacturer's terms)

Frequently Asked Questions - GA 38 GARMIN

Which Garmin plotters is the GA 38 antenna compatible with?

The GA 38 antenna is compatible with Garmin plotters that have an ANTENNA or EXT GPS port with a BNC connector.

How to test the signal before final installation?

Temporarily fix the antenna at the chosen location and check the signal strength on your plotter. Move it if necessary to obtain an optimal or acceptable signal.

What is the safe distance to maintain from a magnetic compass?

The safe distance to compass is 114 mm (4.5 inches) to avoid any interference.

Can I mount the antenna under the deck?

Yes, but only if the deck is fiberglass. The antenna cannot receive GPS signals through metal. Use the supplied adhesive mounts and fix with suitable screws.

What tools are needed for flat deck mounting?

You will need a drill, a 3.2 mm (1/8 in) drill bit for pilot holes, a 25 mm (1 in) hole saw for the cable pass-through, and an anti-seize lubricant for the screws.

How to avoid interference with radar or VHF?

Install the antenna at least 1 meter (3 feet) from the path of the radar beam or VHF antenna. Ideally above the radar beam.

Is the antenna waterproof?

Yes, it is rated IPX7, which means it can be submerged up to 1 meter deep for 30 minutes.

What to do if the M4 screw is too long for under deck mounting?

If the supplied screws go through the mount bracket, you must buy shorter screws suitable for the thickness of your support.

Can I use sealant to seal the cable pass-through?

Yes, after installation, you can fill the vertical slot with sealant for additional protection.

How to clean the GA 38 antenna?

Clean the exterior with a soft cloth and soapy water. Avoid harsh solvents. Regularly check the condition of the seals.

USER MANUAL GA 38 GARMIN

Remote GPS Antenna Installation Instructions

WARNING

See the Important Safety and Product Information guide in the GPS device product box for product warnings and other important information.

CAUTION

Always wear safety goggles, ear protection, and a dust mask when drilling, cutting, or sanding.

NOTICE

When drilling or cutting, always check what is on the opposite side of the surface.

This antenna can be installed to provide a stronger GPS signal to a compatible Garmin chartplotter. This antenna uses a BNC connector to connect to the port labeled ANTENNA or EXT GPS on a compatible Garmin chartplotter.

Antenna Mounting Considerations

You can mount the antenna on a flat surface, install it under fiberglass, or attach it to a standard 1 in. OD, 14 threads per inch, pipe-threaded pole (not included). You can route the cable outside of the pole or through the pole. For optimal performance, consider these guidelines when selecting the antenna mounting location.

• To avoid interference with a magnetic compass, the antenna should not be mounted closer to a compass than the compass-safe distance value listed in the product specifications.
  To ensure the best reception, the antenna should be mounted in a location that has a clear, unobstructed view of the sky in all directions 1.

The antenna should not be mounted where it is shaded by the superstructure of the boat ② a radome antenna, or the mast.
- The antenna should not be mounted near the engine or other sources of Electromagnetic Interference (EMI) ③.
If a radar is present, the antenna should be mounted above the path of the radar 4. If necessary, the antenna may be mounted below the path of the radar 5.

• The antenna should not be mounted directly in the path of the radar ⑥.
  The antenna should be mounted at least 3 ft. (1 m) away from (preferably above) the path of a radar beam or a VHF radio antenna

• On a sailboat, to prevent inaccurate speed readings caused by excessive heeling, the antenna should not be mounted high on the mast.
• The antenna provides more-stable readings when located nearer to water level.

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 countbore through only the top gel-coat layer. This will help to avoid any cracking in the gel-coat layer when the screws are tightened.

Stainless-steel screws may bind when screwed into fiberglass and overtightened. Garmin recommends applying an anti-seize lubricant to the screws before installing them.

Before you permanently mount the antenna, you must test the mounting location for correct operation (Testing the Mounting Location, page 2).

1 Using the surface-mount bracket ① as your mounting template, mark the three pilot-hole locations and trace the cable-hole in the center of the bracket.

2 Set the surface-mount bracket aside. Do not drill through the bracket.
3 Drill the three 3.2mm (1/8 in.) pilot holes.
4 Use a 25mm (1 in.) hole saw to cut the cable hole in the center.

5 Place the seal pad ② on the bottom of the surface-mount 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 ③ through the 25mm (1 in.) hole and connect it to the antenna.
8 Verify the large gasket 4 is in place on the bottom of the 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 set screw ⑤.
10 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 (Testing the Mounting Location, page 2).

1 Route the cable through the pole-mount adapter ①, and place the cable in the vertical slot ② along the base of the pole-mount adapter.

2 Screw the pole-mount adapter onto a standard 1 in. OD, 14 threads per inch, pipe-threaded pole (not included). Do not overtighten the adapter on the pole.
3 Connect the cable to the antenna.
4 Place the antenna on the pole-mount adapter and twist it clockwise to lock it in place.
5 Secure the antenna to the adapter with the included M3 set screw ③.
6 With the antenna installed on the pole mount, fill the remaining gap in the vertical cable slot with a marine sealant (optional).
7 Attach the pole to the boat if it is not already attached.
8 Route 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 (Testing the Mounting Location, page 2).

1 Position a standard 1 in. OD, 14 threads per inch, pipethreaded pole (not included) in the selected location, and mark the approximate center of the pole.
2 Drill a hole using a 19mm (^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 ①.

8 With the antenna installed on the pole mount, fill the vertical cable slot ② with a marine sealant (optional).
9 Route the cable away from sources of electronic interference.

Mounting the Antenna Under the Deck

NOTICE

Before attaching the under-deck mounting bracket to the surface, verify the included screws will not penetrate the surface. If the included screws are too long, you must purchase surface-appropriate screws to complete the installation.

Before you permanently mount the antenna, you must test the mounting location for correct operation (Testing the Mounting Location, page 2).

Because the antenna cannot acquire signals through metal, it must be mounted under a fiberglass surface only.

1 Place the adhesive pads ① on the under-deck mounting bracket ②

2 Place the antenna in the under-deck mounting bracket.
3 Adhere the under-deck mounting bracket to the mounting surface.
4 Secure the under-deck mounting bracket to the mounting surface with screws.
5 Connect the cable to the antenna ③.
6 Route the cable away from sources of electronic interference.

Specifications

MeasurementSpecification
Dimensions (diameter x height)	319/32 × 115/16 in. (91.6 × 49.5 mm)
Weight 7.1 oz (201 g)
Temperature range -22° to 176°F (-30° to 80°C)
Case material Fully gasketed, high-impact plastic alloy
Water rating IEC 60529 IPX7
Compass-safe distance 114 mm (4.5 in.)