10Using a torque wrench, tighten the nuts from 13.7 to 18.6 N- m (10 to 14 lbf-in.) of force.

Connecting the Power Cable

WARNING

When connecting the power cable, do not remove the in-line fuse holder. To prevent the possibility of injury or product damage caused by fire or overheating, the appropriate fuse must be in place as indicated in the product specifications. In addition, connecting the power cable without the appropriate fuse in place will void the product warranty.

1Route the power cable from the device to the power source.

2Connect the red wire to the positive (+) battery terminal, and connect the black wire to the negative (-) battery terminal.

3If you have not already done so, connect the power cable to the device by turning the locking ring clockwise.

Power Cable Extensions

Connecting the power cable directly to the battery is recommended. If it is necessary to extend the cable, the appropriate gauge of wire must be used for the length of the extension.

Distance
Wire Gauge

2 m (6.5 ft.)

16 AWG (1.31 mm²)

4 m (13 ft.)

14 AWG (2.08 mm²)

 

 

6 m (19 ft.)

12 AWG (3.31 mm²)

 

 

Connecting to a Device or to the Marine Network

You can connect the radar either directly to a radar-compatible Garmin device or to a Garmin Marine Network to share radar information with all connected devices.

NOTE: Not all Garmin devices are compatible with the Garmin Marine Network. See the installation instructions or owner's manual provided with your device for more information.

1Route the network cable to your compatible Garmin device.

2If you have not already done so, install the locking rings and o-rings on the end of the network cable.

3Select an option:

•If the Garmin device is not compatible with the Garmin Marine Network, connect the network cable to the port labeled RADAR.

•If the device is compatible with the Garmin Marine Network, connect the network cable to the port labeled

NETWORK.

Radar Operation

All functions of the Garmin radome are controlled with your Garmin chartplotter. See the Radar section of your chartplotter's manual for operating instructions. To download the latest manual, go to www.garmin.com/support/.

Measuring the Potential Front-of-Boat Offset

The front-of-boat offset compensates for the physical location of the radar scanner on a boat, if the radar scanner does not align with the bow-stern axis.

1Using a magnetic compass, take an optical bearing of a stationary target located within viewable range.

2Measure the target bearing on the radar.

3If the bearing deviation is more than +/- 1°, set the front-of- boat offset.

Setting the Front-of-Boat Offset

Before you can set the front-of-boat offset, you must measure the potential front-of-boat offset.

The front-of-boat offset setting configured for use in one radar mode is applied to every other radar mode and to the Radar overlay.

Select Up or Down to adjust the offset.

Specifications

Specification
Measurement

GMR 18 xHD weight

7.7 kg (16.95 lb.)

 

 

GMR 24 xHD weight

9.5 kg (20.9 lb.)

Temperature range

-15 to 70°C (5 to 158°F)

 

 

Case material

Thermoplastic resin

 

 

Default antenna rotation speed

48 RPM

Alternative antenna rotation speed

24 RPM

 

 

Power input source

10.5 to 35 Vdc, 3.5 A

 

 

Power output

4 kW peak

RF transmit frequency

9410 MHz nominal

 

 

Compass-safe distance

1 m (3.28 ft.)

 

 

GMR 18 xHD beam width

3.7°

GMR 24 xHD beam width

5.2°

 

 

Maximum range

48 nm

 

 

Minimum range

20 m (66 ft.)

Range discrimination

16 m (52.5 ft.)

 

 

Range scales

0.125, 0.25, 0.5, 0.75, 1, 1.5, 2, 3,

 

4, 6, 8, 12, 16, 24, 36, 48 nm

Detailed Dimensions

Item
GMR 18 xHD
GMR 24 xHD

Length

508.2 mm (20 in.)

645.4 mm (25 7/16 in.)

À (width)

504.7 mm (19 7/8 in.)

642.5 mm (25 5/16 in.)

Á (height)

248.3 mm (9 ¾ in.)

250.3 mm (9 7/8 in.)

3