GA™ 38 GPS and GLONASS antenna for Cortex® V1 and M1, black

The Garmin GA™ 38 antenna is an external GPS and GLONASS antenna designed to improve positioning signal reception. It is used to enhance the accuracy and reliability of onboard navigation, particularly when the internal antenna of a device is obstructed or to achieve superior GNSS performance.

The Garmin GA 38 antenna supports dual-constellation GPS and GLONASS systems. This capability ensures faster position acquisition and improved accuracy, even in challenging reception conditions.

The Garmin GA 38 antenna has a diameter of 91.6 mm (3 19/32 inches) and a height of 49.5 mm (1 15/16 inches).

The Garmin GA 38 antenna weighs 201 grams (7.1 oz).

The Garmin GA 38 antenna is fully waterproof and compliant with IEC 60529 IPX7 standard. This means it is protected against the effects of temporary immersion in water.

The black model of the Garmin GA 38 antenna can operate within a temperature range of -30°C to 70°C (-22°F to 158°F).

The Garmin GA 38 antenna comes with a 10-metre BNC-SMA cable, providing installation flexibility.

The Garmin GA 38 antenna housing is made from high-impact plastic alloy, fully watertight, ensuring resistance to demanding marine environments.

The Garmin GA 38 antenna is specifically designed for Cortex® V1 and M1 systems. It is also compatible with various Garmin chartplotters, VHF radios, and AIS devices that feature an ANTENNA or EXT GPS port with a BNC connector.

The Garmin GA 38 antenna uses a BNC connector to connect to the port labeled ANTENNA or EXT GPS on a compatible Garmin chartplotter.

The Garmin GA 38 antenna offers several mounting options:

Mounting on a flat surface.Mounting on a standard 1-inch OD mast with 14 threads per inch (mast not included).Deck-mounted installation is not provided with the black models of the antenna.

For optimal performance, the antenna must be mounted in a location with a clear view of the sky in all directions. It is recommended to avoid areas shaded by the boat’s superstructure, a radome, the mast, or near the engine and other sources of electromagnetic interference (EMI). It must also not be mounted near ferrous metal objects or directly in the path of a radar.

The below-deck mounting kit is supplied only with the white antenna models. Therefore, this option is not applicable for the Garmin GA 38 black antenna.

To mount the antenna on a flat surface:

Use the surface-mount bracket as a template to mark the three pilot hole locations and trace the cable hole in the center.Drill the three pilot holes with a 3.2 mm (1/8 in) bit.Drill or cut the central cable hole with a 25 mm (1 in) bit or hole saw.Secure the surface-mount bracket with the included M4 screws.Run the cable through the center hole and connect it to the antenna.Ensure the large gasket is in place on the underside of the antenna, place the antenna on the bracket, and turn it clockwise to lock it in place.Secure the antenna to the mounting bracket with the M3 adjustment screw and a 1.5 mm hex key.

To mount the antenna on a mast (not included, 1" OD, 14 threads per inch):

With the cable routed outside the mast: Pass the cable through the mast mount adapter and place it in the vertical slot. Screw the adapter onto the mast, connect the cable to the antenna, then place the antenna on the adapter and rotate it to lock it in place. Secure with the M3 adjustment screw.

With the cable routed through the mast: Drill a 19 mm (3/4") hole in the mast for the cable. Secure the mast to the boat. Screw the mount adapter onto the mast. Route the cable through the mast and connect it to the antenna. Place the antenna on the adapter and rotate it to lock it in place. Secure with the M3 adjustment screw.

In both cases, ensure you test the location before final installation and route the cable away from sources of electronic interference.

When drilling or cutting, always check what is on the other side of the surface to avoid damaging the boat. If drilling into fiberglass, it is recommended to use a countersink bit to drill a pilot hole only through the top gelcoat layer. This helps prevent cracking of the gelcoat when screws are tightened.

Yes, it is strongly recommended to temporarily test the antenna at the chosen mounting location to verify its proper operation. If interference with other electronic devices is detected, the antenna must be moved and retested until a full or acceptable signal strength is observed before permanent installation.

Yes, the antenna must not be mounted near the engine or other sources of electromagnetic interference (EMI). Additionally, it must not be mounted within 1 meter (3 feet) of a VHF radio antenna or in the path of a radar to avoid interference.

The safe distance from a compass to the Garmin GA 38 antenna is 114 mm (4.5 inches).

The Garmin GA 38 accessory is covered by Garmin's standard limited warranty. For detailed information, consult Garmin's support section on their website.