10
Using 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 voids the product warranty.
1
Route the power cable from the device to the power source.
2
Connect the red wire to the positive (+) battery terminal, and
connect the black wire to the negative (-) battery terminal.
3
If 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.
1
Route the network cable to your compatible Garmin device.
2
If you have not already done so, install the locking rings and
o-rings on the end of the network cable.
3
Select 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
.
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.
1
Using a magnetic compass, take an optical bearing of a
stationary target located within viewable range.
2
Measure the target bearing on the radar.
3
If 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
From -15 to 70°C (from 5 to 158°F)
Case material
Thermoplastic resin
Default antenna rotation speed
48 RPM
Alternative antenna rotation
speed
24 RPM
Power input source
From 11 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 degrees
GMR 24 xHD beam width
5.2 degrees
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, and 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
