Furuno GR-80 User manual

DGPS BEACON RECEIVER
MODEL GR-80

SAFETY INSTRUCTIONS
Position should always be checked
against other sources to confirm
reliability.
GPS position and velocity accuracies are
controlled by the U.S. Department of
Defense.
Turn off the equipment whenever you
feel it is abnormal.
Continued use may damage the equipment
.
The useable temperature range of the
display unit is -15°C to +55°C.
Use in temperature out of the above range
may damage the equipment.
Confirm that the power supply voltage
is compatible with the voltage rating
of the equipment.
Connection to the wrong power supply
can cause fire or equipment damage. The
voltage rating appears on the label at the
rear of the display unit.
Keep the compass safe distance.
CAUTION
Standard compass Steering compass
0.3 m 0.2 m
Do not open the equipment
.
Hazardous voltage which can
cause electrical shock, burn o
r
serious injury exists inside the
equipment. Do not work insid
e
the equipment unless familiar
with electrical circuits.
WARNING

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1
TABLE OF CONTENTS
FOREWORD............................................. 1
A Word to GR-80 Owners.......................1
Features ................................................... 1
SPECIFICATIONS .................................... 2
SYSTEM CONFIGURATION .................. 3
HOW DGPS WORKS ............................... 4
INSTALLATION....................................... 5
Antenna Installation ................................ 5
Receiver Installation ............................... 6
Connections............................................. 6
Interface Format...................................... 7
Initial Settings ......................................... 8
OPERATION ............................................. 9
Turning the Power On/Off ...................... 9
Controls and Indications ......................... 9
Menu Operation .................................... 10
Adjusting Brilliance, Contrast ...............11
Manual Operation ..................................11
Automatic Operation..............................11
Displaying Position............................... 12
Station Scan Time Out .......................... 12
Displaying Signal Strength and
Signal-to-Noise Ratio............................ 12
Remote Control ..................................... 12
TROUBLESHOOTING .......................... 13
Troubleshooting Table .......................... 13
Diagnostic Test...................................... 14
DGPS REFERENCE STATIONS............ 15
EQUIPMENT LISTS............................... 21
CONNECTABLE FURUNO
EQUIPMENT .......................................... 22
REMEDY FOR THE INTERFERENCE
TO AVHF RADIOTELEPHONE ........... 23
TAPING WHIPANTENNA .................... 25
OUTLINE DRAWING .......................... D-1
INTERCONNECTION DIAGRAM ...... S-1
Declaration of Conformity
FOREWORD
A Word to GR-80 Owners
FURUNOElectricCompanythanks you for
purchasing the GR-80 DGPS Beacon Re-
ceiver. We are confident you will discover
why the FURUNO name has become syn-
onymous with quality and reliability.
For over 50 years FURUNO Electric Com-
pany has enjoyed an enviable reputation for
quality and reliability throughout the world.
Thisdedicationtoexcellence is furtheredby
our extensive global network of agents and
dealers.
YourDGPSbeaconreceiver is designedand
constructed to meet the rigorous demands
ofthemarineenvironment.However,noma-
chine can perform its intended function un-
less properly installed and maintained.
Please carefully read and follow the instal-
lation, operation and troubleshooting proce-
dures set forth in this manual.
We wouldappreciatefeedback fromyou,the
end-user, about whether we are achieving
our purposes.
Thank you for considering and purchasing
FURUNO.
Features
The GR-80 receives differential error cor-
rection messages (RTCM SC104 format)
whicharebroadcastby public radiobeacons
operating in the 283.5 to 325 kHz frequency
range. The differential error correction mes-
sages are output via a serial port for use in
theassociatedGPS receiver, resultingindif-
ferentially correction position data with bet-
ter than 10 meter accuracy.
TheGR-80may be controlledfromthe front
panel, or remotely via the serial I/O port.
The I/O protocol is NMEA 0183. Output
format is RS-232C or RS-422 (default).

2
SPECIFICATIONS
Performance
Frequency range 283.5 – 325.0 kHz
Freq. resolution 0.5 kHz
Receiver Single superhetero-
dyne
IF frequency 455 kHz
Input sensitivity 6 dBµV (MSK rate
100 bps, 10-3 bit error)
Data Processing
Modulation MSK
Data coding Dual Costas loop
MSK rate 25, 50, 100, 200 bps
(auto or manual,
selectable)
Beacon Antenna (std. supply)
Gain 6 dB
Protection Can withstand 30
Vrms input for more
than 15 minutes in the
range of 100 kHz to
28 MHz
Interface (protocol)
Data protocol RTCM SC104
Status protocol NMEA 0183
Control protocol NMEA 0183
Level RS-422 or RS-232C
(selectable)
Baud rate 300, 600, 1200, 2400,
4800, 9600, 14400,
19200 bps (selectable)
Interface (position input)
Position input NMEA 0183
Hardware spec. Current loop
Baud rate 4800 bps (fixed)
Power Requirements
Power Forward switching
(floating)
Input voltage 10.2 to 31.2 VDC
Power consumptionLess than 5 W
Mechanical
Dimensions (mm) 105(W) x60(H) x
200(D)
Mass 1 kg
Color 2.5GY5/1.5 (Gray)
Environmental Conditions
Display unit -15°C to +55°C
Antenna unit -20°C to +70°C
Humidity Receiver: 95% (40°C)
Antenna:
100% (40°C)
Water resistance Receiver: IPX-2
Antenna: IPX-6

3
SYSTEM CONFIGURATION
FURUNO DGPS BEACON RECEIVER GR-80
MENU
FREQ
STN ▼▲ENT
RESET
LOCK
RECTIFIER
PR-62
Ship's Mains
12/24 VDC 100/110/200/220 VAC
GPS Navigator
(GPS Plotter) RECEIVER
ANTENNA
COUPLER
GPS Antenna Unit
Whip Antenna

4
Figure 1 DGPS concept
HOW DGPS WORKS
Position accuracy for civil users of GPS is
limited to about 50 meters. This limitation
exists not only because of the US Depart-
ment of Defense's intentional downgrading
of the accuracy but also because of signal
attenuation and clock error inherent in both
GPS satellites and GPS receivers. With Dif-
ferential GPS (DGPS), however, differen-
tial corrections can improve position
accuracy to better than 10 meters.
Differential GPS is based upon accurate
knowledge of the accurate geographical lo-
cation of a reference station which is used
to compute corrections to GPS parameters,
error sources and resultant positions. These
differential corrections are transmitted to
GPSusers,who applythe correctionstotheir
received GPS signals or computed position.
The DGPS reference stations are fixed at a
geodetically surveyed position. The refer-
ence station tracks all satellites in view,
downloads ephemeric data from them, and
computes corrections based on its measure-
ment and geodetic position. These correc-
tions are then broadcast to GPS users by
radiobeacons(transmitters) toimprovetheir
position solution.
The radio beacons broadcast in the fre-
quency range of 283.5–325 kHz and have a
transmitting range from 40 nm to 300 nm
depending on radio beacon.
Reference
station
Corrected data
DGPS Beacon receiver
(GR-80)
GPS
receiver
Radio beacon
(transmitter)
GPS satellite
GPS signal

5
INSTALLATION
Antenna Installation
Siting considerations
• Install the antenna vertically and as high
and far away from surrounding obstacles
as possible.
• Separate the antenna at least three meters
from any transmitter antennas which are
radiating at significant RF power levels.
Mounting the antenna coupler
It can be mounted two ways:
• Thethreadedantenna base acceptsastan-
dard antenna mount with a 1"-14 straight
thread. Mount the antenna on a length of
pipewitha 1"-14 threadedend.DONOT
USE TOOLS TO FASTEN THE AN-
TENNATOITSMOUNTING;ONLY
HAND TIGHTEN. Route the antenna
cable(antennaextension cable) insidethe
pipe.
• Attachtheantennacoupler to asteelmast
with hose clamps (option).
Hose
clamps
Whip
antenna
Steel mast
Ground
terminal
Spring
washer
Figure 2 Attachment of antenna coupler
to steel mast
Mounting of whip antenna
Screw in the whip antenna in the hole at the
top of the preamp unit. Coat junction with
silicone rubber.
Ground
Ifthe preamp unitisattached toasteel mast,
run a ground wire between the ground ter-
minalonthe preampunit andastainless steel
bolt welded to the mast. The ground wire
should be as short as possible. (It is also rec-
ommended to ground the preamp unit when
it is attached to a non-metallic mast.)
Ground the equipment to
prevent loss of sensitivity.
CAUTION
Connection of antenna cable
The antenna cable (15 m) is attached to the
preamp unit. When optional 30 m or 60 m
cable is used, tape the junction with self-
vulcanizing tape and vinyl tape to water-
proof the cable. Finally, attach cable tie near
ends of tape to prevent unwinding.
Figure 3 How to tape the antenna cable
Connection of RG-10UY cable
Use the Antenna Cable Set (option) to con-
nect the RG-10UY cable.
GR-80
*Cable Assy.
RG-10UY
*: Antenna Cable Set parts
*N-P-7
*TNC-SA-JJ
*Cable Assy.

6
Receiver Unit Installation
Siting considerations
The receiver can be mounted on a tabletop,
on the overhead or in a panel (requires op-
tional flush mount kit). When selecting a
mountinglocationkeep the followingpoints
in mind;
• Locate the receiver away from rain and
water splash.
• Keep the receiver away from heat
sources.
• Install the receiver out of direct sunlight.
• The viewing angle of the front panel is
±45°.
• Leave at least 100 mm space behind the
receiver and 80 mm space at the sides to
permit easy access to connectors at the
rear and knobs at the sides.
Tabletop or overhead mounting
1. Fix the hanger to the mounting location
with tapping screws.
2. Loosely screw knobs into the receiver.
Set the receiver to the hanger and tighten
knobs.
Flush mounting (option)
See outline draing at the end of the manual.
Note: Remove gasket at right and left sides
of receiver before mounting in panel.
FURUNO DGPS BEACON Gasket
(both sides)
Figure 4 GR-80 receiver unit
Note: For flush mounting, use only the
screws supplied with the flush mount kit to
fix the receiver. Use of other screws may
damage the equipment.
Connections
2A POWER DATA ANT
+-
10.2-31.2 VDC
Fuse
(2A)
Power cable
connector
I/O cable
connector
Antenna ca
b
connector
Ground terminal
Figure 5 Connections on rear
panel of receiver
Power cable
Apower cable, complete with connector, is
supplied. Connect the leads to the power
supply; red wire to positive (+) terminal and
black wire to negative (–) terminal.
The receiver does not have a power switch.
We recommend that a switch be dedicated
to the receiver on the mains switchboard.
Antenna cable
Connect the cable to the ANT connector.
I/O input cable
The 7-pin DATA connector connects the
GPS navigator. A signal cable is supplied
with the navigator; attach the connector
(FM14-7P) supplied with the GR-80 to the
cable. For no signal cable the following
cables are optionally available:
epyTelbaC.oNedoCskrameR
050-3000FPS6A-JM306-711-000m5,P6
050-3000FPS7A-JM037-631-000m5,P7
Note: If the GR-80 is causing interference
to a VHF radiotelephone, follow the proce
dure on page 23.