JRC JLR-21/JR-31 satellite compass 9pu



Display modes

The JLR-31/JLR-21 incorporates many display modes readily available on a highly visible 5.7 inch LCD display. The display is fully dimmable and the keys are also backlit, making it easy to operate in low-light settings on the bridge.

Simple operation

The compact design of the JLR-31/JLR-21 incorporates an intuitive interface, providing enhanced ergonomics and user friendliness. The logic of the controls and excellent on-screen menus will greatly shorten most users’ learning period.

Image:Display modes

Measuring tool

The GPS compass allows calculation of distance and bearing between any two points, supporting Rhumb Lines (RL) for the short legs and Great Circle (GC) for long distance legs. Also, a trip log function comes standard for distance and heading.

Image:Measuring tool

CCRP and Anchor watch

The JLR-31/JLR-21 has CCRP¹ function incorporated, allowing the transfer of CCRP sentences to other onboard equipment and anchor watch alerts the watch officer of possible anchor dragging situations.

1. Consistent Common Reference Point

Image:CCRP and Anchor watch

Trend graph

The new trend graph display mode shows a history of roll, pitch and heave and SOG as an easy-to-read graphical view. Selections can be made to show maximum or average results.

Image:Trend graph

Antenna design

The processor is built into the antenna. Eliminating alignment between antenna and processor found in separate systems, therefore contributing to an easy setup with less error and significantly reduced installation time. This concept also reduces the installation costs as only a single cable is used between antenna and display unit.

The outer shell of JRC’s new antenna system has a smooth surface. This slippery exterior makes it almost impossible for birds to perch on the domes or for the antennas to be completely covered in snow.

Should something interfere with the coverage, JRC’s proven antenna design incorporates a layer of air that reduces possible blind spots, allowing for a more precise heading than conventional systems.

Image:Antenna design

High speed tracking

The GPS compass has its origins as a direction sensing system, but the JLR-31/JLR-21 goes far beyond that. The JLR-31/JLR-21 provides an impressive heading accuracy of 0.25° rms (JLR-31)/0.50° rms (JLR-21). Heave accuracy is 20cm rms and roll and pitch for both models is 0.5° rms. The tracking Rate of Turn (ROT) is 45° per second.

On the right a comparison between previous GPS compass model (JLR-30/JLR-20) and the new model (JLR-31/JLR-21).

Image:High speed tracking

Technical Specification


Name GPS Compass/GPS Navigator
Model JLR-21 JLR-31
IMO approved (THD)
IMO approved (GPS)
Model NNN-21 NNN-31
Receiver Type Multi channel all-in-view (12ch + 1ch SBAS)
Frequency 1575.42MHz ± 1MHz(C/A code)
Direction accuracy 0.5° rms 0.25° rms
Rolling accuracy 0.5° rms
Pitching accuracy 0.5° rms
Heaving accuracy 20cm rms
Display resolution 0.1°
Resolution output 0.1° or 0.01° (selectable)
Tracking Rate of Turn 45° / sec
Tracking acceleration 1G
Start-up time less than 2 minutes (warm start fix, typically 30 seconds)
DGPS input RTCM SC-104 Ver.2.0 Type 1, 2, 9, 16
SBAS receiver Built-in(MSAS/WAAS/EGNOS)
RAIM function Built-in
Position accuracy GPS : 12m 2drms (C/A code, HDOP≦4, SA OFF)
SBAS : 6m 2drms when SBAS corrected
DGPS : 4m 2drms when DGPS corrected (when connected to beacon receiver)
GPS : 12m 2drms (C/A code, HDOP≦4, SA OFF)
SBAS : 5m 2drms when SBAS corrected
DGPS : 3m 2drms when DGPS corrected (when connected to beacon receiver)
Protection IPX6
Ambient conditions -25 to +55°C (operational)
-25 to +70°C (storage)
Model NWZ-4701
Display 5.7-inch LCD, 320 by 240 pixels
Display modes Compass rose, bow heading, navigation, rate of turn (ROT), water/ground speed, trend graph, calculation, GPS status
Direction & nav. data output1 IEC61162/NSK(shared) 5 ports (AD-10 output availuable: 2 of 5 ports)
Current data input 1 port(CUR, VBW)
Alarm contact signal 2 ports (alarm output)
1 port (ACK input)
LOG pulse 1 port (off , 200p/NM, 400p/NM)
Protection IPX4
Ambient conditions -15 to +55°C (operational)
-25 to +70°C (strage)
Power 12 to 24V DC (-10% to +30%)
Power consumption 12W (including sensor), 6W (excluding sensor)
Vibration/EMC IEC60945 ed4
Rectifier NBG-320
Data cable (for serial data) CFQ-5374 (3m), CFQ-5374-15 (15m)
Data cable (for contact signal) CFQ-5404 (3m), CFQ-5404-15 (15m)
Extention cable (sensor-display) CFQ-7249 (20m), CFQ-7249-10 (10m)
Junction box NQE-7720
Data cable (for sub display) CFQ-7251 (1.5m Y-cable)
Data cable (for JRC Radar)2 CFQ-5469 (10m)
Data cable (for beacon receiver) CFQ-7250
Mount base (for NNN-21) MPBX44117
  • Selectable sentences depend on versions (NMEA 1.5, 2.1, 2.3) Some combinations of output sentence, bit rate, and output intervals may not be possible
    ATT and HVE sentence can be set from output cycles of 25ms, 50ms,100ms, 200ms, 1s, 2s only
  • Accepted for JMA-3300/5100/5200/5200MK2/5300/5300MK2 series


Image:Dimension:Display NWZ-4701

Antenna (JLR-31)

Image:Dimension:Antenna (JLR-31) NNN-31

Antenna (JLR-21)

Image:Dimension:Antenna (JLR-21) NNN-21


Image:Dimension:Rectifier NBG-320

Standard in the box

  • Display
  • Antenna
  • Cables
  • Installation parts
  • Spare parts
  • Manual


Power cable display 2 m
Serial data cable 3 m
Display to antenna* 10 m

*The cable length may vary depending on sales region.


Serial data cable CFQ-5374 (3 m)
Sensor extension cable CFQ-7249 (20 m)
Flush mount kit · MPBC43664
AC power rectifier · NBG-320
DGPS receiver JLR-4341

All specifications are subject to change without notification.



JLR-21 Brochure




JLR-31 Brochure



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