Garmin GMR xHD3 4’ radarántenna

Yes, it is imperative to ground the GMR xHD3 4' radar antenna housing.

To do this, you will need a 3.31 mm² (12 AWG) copper wire (not included). This wire must be connected to the boat's nautical ground. It is important to note that this ground connection must be made to the nautical ground and not to the battery's negative terminal.

For physically installing the radar antenna, you will need the following tools:

A Phillips screwdriver size #2. A 5 mm and a 6 mm Allen key. A drill and a 15.0 mm (19/32 in) bit for mounting holes. A 32 mm (1 1/4 in) bit if you need to run cables through the mounting surface. A 17 mm (21/32 in) wrench and a torque wrench. 3.31 mm² (12 AWG) copper wire for grounding the radar housing. Marine sealant.

Yes, installing the radar antenna by an unqualified person or incorrect handling can significantly impact the product warranty.

Opening the device by anyone other than an authorized Garmin service technician will void the product warranty. Similarly, not installing the device according to the provided instructions—including using the correct fuses or removing the inline fuse—voids the warranty. For optimal performance and to avoid potential injury or damage to the device or vessel, installation by a qualified marine installer is strongly recommended.

Yes, the Garmin GMR xHD3 4' radar antenna is designed to integrate seamlessly with existing navigation systems.

It is compatible with Garmin BlueNet™ and Garmin Marine Network networks. This compatibility ensures smooth visualization and control from compatible Garmin multifunction displays, enabling seamless integration within your vessel's Garmin ecosystem.

Several important safety precautions must be observed when installing and using the GMR xHD3 4' radar antenna:

The radar transmits electromagnetic energy. To avoid bodily injury, ensure the radar is installed beyond the reach of people, with the vertical beam above head height. Before powering on the radar, confirm that all personnel are clear of the radar beam path. Never look directly at the antenna at close range while the radar is transmitting, as the eyes are the most sensitive part of the body to electromagnetic energy. The device must be used solely as a navigation aid. Any use requiring precise measurement or direction, distance, location, or topography may result in bodily injury or damage to the vessel. When drilling or cutting, always wear safety glasses, hearing protection, and a dust mask to prevent injury. Always check what is on the other side of the surface before drilling or cutting to avoid damaging the vessel.

For the installation of the GMR xHD3 4' radar antenna, you will need the following tools:

A Phillips screwdriver size #2
A 5 mm hex wrench
A drill with a 15.0 mm (19/32 in) bit
A 17 mm (21/32 in) wrench and a torque wrench
A 3.31 mm² (12 AWG) copper wire for grounding the radar housing (and the voltage converter, if applicable)
Marine sealant

When choosing the mounting location, the following points must be taken into account:

The radar must be mounted out of reach of people, with the vertical beam width above head height. It must be installed high above the vessel's keel line, with minimal obstruction of the radar beam. The mounting surface must be flat, parallel to the vessel's waterline, and sufficiently robust. The location must allow connection to power, ground, and the network. The radar beam propagates vertically at 11.5° above and 11.5° below the radiating element. Shims may be used if necessary to adjust the angle. The radar must be kept away from heat sources (exhausts, lights) and installed at a different level from spreaders and mast crossarms. It must be kept away from magnetic compasses (specified safety distance in the product specifications). Other electronic equipment and cables must be more than 2 m (6.5 ft) from the radar beam path. GPS antennas must be either above or below the radar beam path. The radar must be at least 1 m (40 in) from any transmitting equipment and cables carrying radio signals (VHF radios, cables, antennas). It must be at least 2 m (6.5 ft) from SSB radios (single sideband).

To prepare the mounting surface:

Secure the provided mounting template to the surface along the bow-stern axis as indicated on the template. Drill the mounting holes using a 15 mm (19/32 in) drill bit. If you need to route the power and network cables through the mounting surface, select a location along the central channel indicated on the template, drill a 32 mm (1 1/4 in) pass-through hole, and route the cables (optional). Remove the mounting template from the surface.

To securely mount the radar to the mounting surface without damaging it, tighten the hex nuts to a torque of 14.7 N·m (11 lbf·ft).

Once the radar base is mounted, follow these steps to install the antenna:

Remove the protective cover from the waveguide on top of the base. Remove the mounting hardware (screws and washers) from the underside of the antenna. Align the base waveguide with the socket under the antenna and slide the antenna onto the base. Secure the antenna to the base using the hex bolts, spring washers, and flat washers removed from the antenna. Use a torque wrench to tighten the hex bolts to 0.81 kgf-m (70 lbf-in or 5.83 lbf-ft) to secure the antenna without damaging it.

When installing cables, the following considerations must be observed:

A 32 mm (1 1/4 in) diameter hole may be required for cable routing; apply marine sealant after positioning the cables to ensure watertightness. The ground cable is not included and must be connected to a marine ground, not the battery's negative terminal. Use appropriate cable ties, fasteners, and sealant to secure the cable along its route and through bulkheads or the deck. Avoid routing cables near moving objects, high-heat sources, or through doors and bilges. Do not run network and power cables parallel to other cables (radio antenna lines, power cables) to prevent interference. If unavoidable, cables must be shielded. Install the power cable as close as possible to the battery source. If an extension is necessary, use the appropriate wire gauge.

If your model is supplied with a voltage converter, follow these steps:

The voltage converter requires an input voltage of 10 to 32 V DC and must be installed as close as possible to the power source. Run the power cable to the radar and the voltage converter. Use crimp connectors and heat-shrink tubing to connect the power cable to the voltage converter. The radar's power cable includes a 15 A fuse that must not be removed. Connect the voltage converter to the boat's battery via the included 30 A fuse. Both fuses (15 A and 30 A) must be in place for the radar to operate correctly. Connect the power cable to the radar's POWER port. Warning: Do not use old Garmin voltage converters or third-party converters. Using a converter other than the included one or a compatible Garmin converter may damage the radar or prevent it from powering on.

Yes, some radar models do not require a voltage converter and are not supplied with one. In this case, you can connect the power cable directly to the boat’s battery (11 to 32 V DC).

However, if your radar was supplied with a voltage converter, you must install it with the converter for the radar to function correctly.

Warning: When connecting the power cable, do not remove the inline fuse holder. The appropriate 15 A fuse must be in place to prevent risk of injury or damage to the product.

The GMR xHD3 4' radar antenna is compatible with Garmin BlueNet™ and Garmin Marine Network networks.

No, it is essential not to reuse old Garmin voltage converters from previous radar models, nor to use third-party voltage converters. Using any converter other than the one included with the radar, or a correctly purchased converter from Garmin or an authorized Garmin dealer, could damage the radar or prevent it from powering on.

The radar beam of the GMR xHD3 4' antenna propagates vertically at 11.5° above and 11.5° below the radiating element of the radar.

No, this device contains no user-serviceable parts. It must only be opened by a technician authorized by Garmin. Any damage resulting from opening the unit by someone other than a Garmin-authorized service technician will not be covered by the Garmin warranty.

This radar antenna must only be used as a navigation aid. Using the device for tasks requiring precise measurement or direction, distance, location or topography may result in bodily injury or damage to the vessel.

Several actions can void the product warranty:

Connecting the power cable without the appropriate fuse in place. Opening the device by anyone other than a technician authorized by Garmin.

Yes, the radar antenna must be grounded. The grounding cable, which is not included, must be connected to a marine ground—not to the battery's negative terminal.