Page 3 - iiiiiiiiiiiii; The level of risk appearing in the notices is defined as follows:; SAFETY INSTRUCTIONS; CAUTION
iiiiiiiiiiiii i "WARNING" and "CAUTION" notices appear throughout this manual. It is the responsibil-ity of the operator and the installer of the equipment to read, understand and follow thesenotices. If you have any questions regarding these safety instructions, please contact aFURU...
Page 4 - ii; Safety Instructions for the Operator; Do not open the equipment.; Electrical shock can result.; Keep heater away from equipment.; WARNING
ii Safety Instructions for the Operator Use the proper fuse. Use of a wrong fuse can result in fire orpermanent equipment damage. Do not use the equipment for other thanits intended purpose. Personal injury can result if the equipmentis used as a chair or stepping stool, forexample. Do not place obj...
Page 5 - iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii; iii; Safety Instructions for the Installer; Use the correct fuse.
iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii iii Safety Instructions for the Installer Do not work inside theequipment unless totallyfamiliar with electricalcircuits. Hazardous voltage which cancause electrical shock, burn or serious injury exists inside the equipment. Wear a safety belt and hardhat when...
Page 6 - Outputting Cursor Position to; DISPLAY; The Radar Wave and Radar Horizon21; TROUBLESHOOTING; TABLE OF CONTENTS
v FOREWORD ................................ v SPECIFICATIONS ..................... vii EQUIPMENT LIST ...................... ix CONFIGRATION ......................... xi 1. PRINCIPLE OF OPERATION ............................. 1 1.1 What is Radar? ................................. 1 1.2 How Ships Det...
Page 7 - vi; Features; FOREWORD
vi Congratulations on your choice of theFURUNO MODEL 841 MARK-2 MarineRadar. We are confident you will see whythe FURUNO name has become synony-mous with quality and reliability. For over 40 years FURUNO Electric Com-pany has enjoyed an enviable reputation forinnovative and dependable marine electro...
Page 8 - vii; Antenna Unit; SPECIFICATIONS
vii Antenna Unit 1. Radiator Printed array 2. Radiator length 54 cm 3. Horizontal beamwidth 3.9 ° 4. Vertical beamwidth 20 ° 5. Sidelobe -20 dB within main lobe-23 dB outside main lobe 6. Polarization Horizontal 7. Antenna rotation speed 24 rpm 8. Wind resistance Relative wind speed 100 kts (51.5 m/...
Page 9 - viii; Total amplitude; Ambient temperature; Interface NMEA; Input; RSD : A cycle of four seconds
viii Stand-by (ST-BY), Echo Trail Time(TRAIL), Variable Range Marker(VRM), Range, Range Ring Interval,Range and Bearing to Cursor (+), OffCenter (OFF CENTER), Watchman(WATCHMAN)With navigation input (option): Course(CRS), Latitude and longitude, Speed(SPD), Range and bearing to waypoint(WP), Cross T...
Page 10 - ix; EQUIPMENT LIST; Complete Set; ll; il
ix EQUIPMENT LIST Complete Set . o N e m a N e p y T . o N e d o C y t Q s k r a m e R 1 t i n u a n n e t n A 8 5 0 - 1 7 0 0 - B S R 1 2 t i n u y a l p s i D 2 M 4 - 3 1 1 - P D R 1 3 s t r a p e r a p S 0 0 8 9 0 - 3 0 P S 1 4 4 - 5 8 0 - 0 0 0 t e s 1 4 s e i r o s s e c c A 0 0 9 5 0 - 3 0 P F...
Page 11 - Optional Equipment; li
x Optional Equipment . o N e m a N e p y T . o N e d o C y t Q s k r a m e R 1 r e i f i t c e R 2 6 - R P 4 8 4 - 3 1 0 - 0 0 0 1 C A V 0 0 1 5 8 4 - 3 1 0 - 0 0 0 C A V 0 1 1 6 8 4 - 3 1 0 - 0 0 0 C A V 0 2 2 7 8 4 - 3 1 0 - 0 0 0 C A V 0 3 2 2 r e z z u B l a n r e t x E 6 3 1 - 3 0 P O 3 4 4 - 6...
Page 12 - xi; CONFIGURATION
xi 5A NAV Video Sounder Gyro Gyro Converter AD-100 *Equivalent to NMEA0183 Option IEC 1162* IEC 1162* (In/Out) (In) Fluxgate Heading Sensor C-2000 Antenna Unit Remote Display FMD-811 External Alarm Buzzer OP03-136 Rectifier PR-62 10.2~31.2VDC 115/230VAC MODEL 841 MARK-2 CONFIGURATION
Page 13 - The Radar Display; PRINCIPLE OF OPERATION
1 1.1 What is Radar? The term "RADAR" is an acronym mean-ing RAdio Detection And Ranging. Al-though the basic principles of radar weredeveloped during World War II, primarilyby scientists in Great Britain and the UnitedStates, the use of echoes as an aid to navi-gation is not a new developme...
Page 14 - Figure 1-1 How radar works
2 Figure 1-1 How radar works A B C D Own ship(radar) D A B C Heading line Targets Own shipin center Range and bearingof a target, relativeto own ship, arereadable on the PPI. (A) Bird's eye view of situation (B) Radar picture of (A)
Page 15 - Control Description; Figure 2-1 Control panel
3 2. OPERATION 2.1 Control Description Cursor padShift cursor, VRMand EBL; selectitems and optionson menu. Selects display mode; erases heading error indication. Turns power on/off. Adjusts display brilliance. Sets radar in stand-by;transmits radar pulse. Selects radar range. Plots targets' trails. ...
Page 16 - Turning the Radar On and Off; Turning the radar on; Display Indications and Markers; Figure 2-2 Display indications
4 0.5 Range Range ring interval Echo trail, AUTO tuningEcho trail elapsed time,echo trail time, tuning indicatorGuard zoneFast Time Constant(rain clutter suppressor)Echo stretchInterference rejector EBL Range ring Cursor Heading marker Guard zone area VRM HDG 326.8° SP Pulsewidth Heading (requireshe...
Page 17 - Selecting the Range; • When navigating in or around crowded; Procedure; Figure 2-3 Display for adjustment of; Procedure; ) Press the cursor pad to select Backlight/
5 2.4 Transmitting After the power is turned on and the mag-netron has warmed up, ST-BY (Stand-By)appears at the screen center. This means theradar is now fully operational. In stand-bythe radar is available for use at anytime—but no radar waves are being transmitted. Press the [ST-BY TX] key to tra...
Page 18 - General procedure; GAIN; Figure 2-4 Display for adjustment of; Figure 2-5 Effect of STC
6 2.8 Adjusting GAIN, STC, A/CRAIN and FTC General procedure The [ECHO] key enables adjustment of thegain, STC, A/C RAIN and FTC. 1) Press the [ECHO] key. The following dis- play appears. AUTO 1 2 3 MAN AUTO 1 2 3 MAN GAIN STC ◆ ◆ [[ A/C RAIN 00 FTC 0 1 2 12 ECHO KEYTO EXIT Currentlevel Item selecte...
Page 19 - Adjusting FTC; Tuning the Receiver; Figure 2-7 Tuning indicator; Manual tuning; ) Press the cursor pad to select Tuning.; How to tune manually
7 How to adjust A/C RAIN and FTC(suppressing rain clutter) The vertical beamwidth of the scanner is de-signed to see surface targets even when theship is rolling. However, by this design theunit will also detect rain clutter (rain, snow,hail, etc.) in the same manner as normal tar-gets. Figure 2-6 s...
Page 20 - Figure 2-8 Measuring range by the VRM; Measuring the Bearing; By cursor; ) Press the cursor pad to bisect the target; Measuring the Range; By range rings; key to display the VRM.
8 1.5 NM 0.5 VRM range VRM Target VRM EBL + CURSOR 0.675 NM 220.9° R 0.675 NM 308.7° R Figure 2-8 Measuring range by the VRM 2.11 Measuring the Bearing There are two ways to measure the bearingto a target: by the cursor, and by the EBL(Electronic Bearing Line). By cursor Operate the cursor pad to bi...
Page 21 - Figure 2-9 Measuring bearing by the EBL; Tips for measuring the bearing; Figure 2-10 Main menu; Menu description
9 To erase the EBL, press and hold down the[EBL] key for about three seconds. 1.5 NM 0.5 EBL Target EBLbearing VRM EBL + CURSOR 0.675 NM 300.1° R 0.675 NM 300.1° R Figure 2-9 Measuring bearing by the EBL Tips for measuring the bearing • Bearing measurements of smaller targets are more accurate; the ...
Page 22 - Table 1-1 Menu description; Menu
10 Table 1-1 Menu description Menu Function 1. Selects control panel backlighting; four is maximum backlighting.2. Selects brilliance for echo trails and markers; four is maximum brilliance. 1. Selects pulselength for 1.5 and 3 mile ranges.2. Selects radar interference rejector level; 3 provides hig...
Page 23 - Figure 2-11 Display modes
11 2.13 Selecting the DisplayMode The display mode may be selected with the[DISP MODE] key. Four modes are avail-able (with navigation input): Normal, Nor-mal + Window, Normal + Nav Data, andNormal + Window + Nav Data. Each time the key is pressed the displaymode changes in one of the sequences show...
Page 24 - The Window Display; Selecting the type of window display; ) Select Window Display to Zoom or Wide; Selecting the area for the zoom picture; ) Press the cursor pad to place the circle
12 2.14 The Window Display The window display appears at the bottomright (or left) 1/4 of the display. Two typesof window displays are available: zoom andwide. Zoom doubles the size of the area se-lected by the operator, and wide (range-up)compresses and displays the entire radar pic-ture on the nex...
Page 25 - Figure 2-13 In and out alarms; Setting the guard zone
13 WPT-UP (waypoint-up) An azimuth stabilized display in which theline connecting the center with the top ofthe display indicates the bearing to the “TO”waypoint, which is selected on the naviga-tional equipment connected to the radar.When navigating a route and own ship en-ters the arrival zone of ...
Page 26 - • When the radar range is less than one half; Figure 2-14 How to set a guard zone; est degree of interference rejection
14 pressing the [GUARD] key. When this isdone, G (ACKN) replaces G (IN) (or G(OUT)). Press the [GUARD] key again to reactivatethe alarm. G (IN) (or G (OUT)) replaces G(ACKN). Canceling the guard zone Press and hold down the [GUARD] key untilthe guard zone disappears. Notes on the guard alarm • When ...
Page 27 - Selecting Pulselength; ) Select Pulselength to SHORT or LONG; Off Centering the Display; ) Locate the cursor where you want to the
15 corner on the display when the interferencerejection circuit is turned on. 2.18 Suppressing NoiseInterference Noise interference appears on the screen asmany bright dots. These dots can be sup-pressed by turning on the noise rejector. Notehowever that there are some forms of noiseinterference whi...
Page 28 - Starting echo trail; Figure 2-17 Appearance of echo trails; Fixed time trails
16 2.21 Echo Trails You can show the trails of targets in after-glow. This function is useful for alerting youto possible collision situations. Starting echo trail Press the [TRAIL] key to start the echo trailfunction. Afterglow starts extending fromtargets and "TRAIL" and the echo trail tim...
Page 29 - Figure 2-18 Sample nav data display; Setting up the nav data display; Figure 2-19 Nav data menu; Turning echo stretch on or off
17 1.5 NM 0.5 HDG 326.8° 66° 04. 00N 166° 04. 00E VRM EBL + CURSOR 0.675 NM 240.1° R 0.646 NM 308.7° R DEPTH XTE SPD 350.0m 0.05NML 30.0KT WAYPOINT POSI L/L 12.0 NM 45.0° M AUTO Figure 2-18 Sample nav data display Setting up the nav data display 1) Press the [MENU] key. 2) Select Nav Data and press ...
Page 30 - How watchman works; Figure 2-21 How watchman works; Turning on watchman; with the guard alarm function.
18 4) ON or OFF. 5) Press the [ENT] key followed by the [MENU] key. ES appears at the top rightside on the display when the echo stretchfeature is on. Note 1: This function magnifies not only tar-gets but also sea clutter and radar interference.For this reason be sure the controls for adjust-ment of...
Page 31 - Canceling watchman; Deselecting Ranges; Active ranges appear in reverse video.; ) Select the Nav Data menu and press the; ST–BY; Figure 2-22 Navigation data display
19 Canceling watchman Press any key while the radar is transmit-ting. (Pressing a key during stand-by causesthe radar to go to warm-up condition.) 2.27 Erasing the HeadingMarker The heading marker continuously appearson the display and shows your vessel’s head-ing. When this mark obscures a target e...
Page 32 - Visual Alarm Indications; Table 2-1 Visual alarm indications
20 2.30 Outputting CursorPosition to Navigator Cursor position (NMEA0183 data sentenceTLL) can be output to the navigator con-nected to this radar by pressing and holdingdown the [HM OFF] key. 2.31 Displaying CursorPosition, Range and Bearing toCursor The cursor data indication at the bottom ofthe d...
Page 33 - Radar horizon; Figure 3-1 Radar horizon; How the radar wave travels; INTERPRETING THE DISPLAY
21 Radar horizon Radar is essentially a “line-of-sight” phe-nomenon. That means you have just aboutthe same range to horizon with a radar asyou do with your own eyes. However undernormal atmospheric conditions, the radarhorizon is 6% greater than the optical hori-zon. Therefore, if the target does n...
Page 34 - Figure 3-2 Range resolution; Bearing Resolution; Figure 3-3 Bearing resolution; Multiple echoes
22 On the other hand, hulls made from woodor fiberglass return much weaker echoes. Vertical surfaces, such as a cliff, are goodtargets provided they face the radar. Con-versely, horizontal and smooth surfaces suchas mudbanks, sandy beaches, and gentlysloping hills make poor targets because theydispe...
Page 35 - Indirect echoes; • their shapes may indicate they are not di-
23 Indirect echoes Indirect echoes may be returned from eithera passing ship or returned from a reflectingsurface on your own ship, for example, astack. In both cases, the echo will return froma legitimate contact to the antenna by thesame indirect path. The echo will appear onthe same bearing of th...
Page 36 - Blind and shadow sectors; Figure 3-7 Blind and shadow sectors
24 Blind and shadow sectors Funnels, stacks, masts, or derricks in the pathof antenna may reduce the intensity of theradar beam. If the angle subtended at thescanner is more than a few degrees a blindsector may be produced. Within the blindsector small targets at close range may notbe detected while...
Page 37 - Safety Information; ELECTRICAL SHOCK HAZARD; RF RADIATION HAZARD
25 This chapter tells you how to keep your ra-dar in good working order. Before review-ing this chapter please read the safetyinformation which follows. 4.1 Safety Information ELECTRICAL SHOCK HAZARD T h i s e q u i p m e n tuses high voltageelectricity whichcan shock, burn orc a u s e d e a t h .Wh...
Page 38 - Table 4-1 Recommended maintenance program
26 4.2 Preventative Maintenance Regular maintenance is important for goodperformance. Always keep the equipment asfree as possible from dirt, dust, and watersplashes. Make sure all screws securing thecomponents are properly tightened. A maintenance program should be estab-lished and should at least ...
Page 39 - Table 4-2 Troubleshooting table
27 4.4 Troubleshooting Table 4-2 contains simple troubleshootingprocedures which you can follow to try torestore normal operation. If you cannot re-store normal operation, do not attempt tocheck inside any unit of the radar system.Any repair work is best left to a qualifiedtechnician. Table 4-2 Trou...
Page 41 - Unpacking the antenna unit; Figure 5-2 Antenna unit; Antenna Unit Installation; Siting, handling considerations
29 ¡ The compass safe distance should be ob-served to prevent deviation of the magneticcompass. s s a p m o c d r a d n a t S s s a p m o c g n i r e e t S m 9 . 0 m 7 . 0 ¡ Do not paint the radome to ensure properemission of the radar waves. ¡ When this radar is to be installed on largervessels, co...
Page 42 - Mounting platform; Holes for antenna unit:; Prepare a platform of 5 to 10 millimeters in; Figure 5-3 Assembling the sailboat mast; Figure 5-5 How to fasten the radome base; Wiring and final preparation; Drill a hole of at least 20 millimeters diam-
30 Mounting platform Holes for antenna unit: The mounting surface must be parallel withthe waterline and provided with five holeswhose dimensions are shown in the outlinedrawing attached at the end of this manual. The unit is adjusted so a target echo returnedfrom the bow direction will be shown on ...
Page 43 - Figure 5-7 Signal cable, antenna unit side; Figure 5-9 How to attach EMC core; Display Unit Installation; Mounting considerations; Figure 5-10 How to position the radome
31 7. Pass the cable through the hole at the bot- tom of the radome base. 8. Secure the cable with the cable clamping plate and gasket. Ground the shield and vi-nyl wire by one of the screws of the cableclamping plate. 9. Connect the wire to the RF unit. to one of the screws of the cable clamping pl...
Page 44 - ) Using the hanger as a template, mark screw; Cutting size for flushmount; Figure 5-11 How to mount the display unit
32 • Make sure you allow enough clearance both to get to the connectors behind the unitand to allow you to get your hands in onboth sides to loosen or tighten the mount-ing knobs. Make sure you leave at least afoot or so of “service loop” of cables be-hind the unit so it can be pulled forwardfor ser...
Page 45 - Connections; Signal cable connection; Connect the signal cable to DJ-1 on the rear
33 Connections Connect the signal and power cables, theground wire and optional equipment as shownin Figure 5-12. RP HDG NMEA DJ-1 OPTION MARINE RADAR TYPESER.NO.DATECOMPASS SAFE DISTANCESTD M STEER M EQUPMENT CLASSFURUNO ELECTRIC CO., LTD 10.2-31.2VDC 3 GND 1 2 Signal cable connector Connect signal...
Page 46 - The OPTION connector; ) Remove the plastic cover on the connector.; ) Cover signal cable at junction with display
34 Navigation aid, video sounderconnection If your navigation aid can output data inNMEA 0183 data format, your vessel’s posi-tion in latitude and longitude, the range andbearing to waypoint, speed, and course maybe input to this radar, and be seen in the bot-tom text area. Further, if your video so...
Page 47 - Installation Check List
35 J55 (NMEA) SPU9180 TLL, RSD J61 Navaid Echosounder Video plotter MODEL 841 M2 The position data from navaid can be used for the echosounder if a video plotter is not connected. Procedure 1. Unfasten the nuts fixing the waterproof con- nector to remove the covers of the power anddisplay unit. 2. R...
Page 48 - Initial Adjustment of Picture; Figure 5-14 Display for adjustment of gain,; if it is not already selected.; ) Turn on the power while pressing and hold-; Figure 5-15 main menu; ) Press the cursor pad to select Installation; Figure 5-16 Installation setup menu 1; ) To display the Installation Setup 2 menu,; Figure 5-17 Installation setup 2 menu
36 5.4 Initial Adjustment of Picture Follow the procedure below to obtain properradar picture. 1) Press the [POWER] key on the display unit. The display should light. Wait until the mes-sage “ST-BY” appears on the screen. (About1:30. 2) Press [TX ST-BY] key to transmit. The ra- dar will start transm...
Page 49 - Entering Initial Settings; ) At the Installation Setup 1 menu, press; Relative Bearing Alignment; ) Display the Installation Setup 2 menu.; Figure 5-18 Installation setup 2 menu; ) Press the cursor pad to bisect the target se-; Figure 5-19 Examples of improper and
37 5.6 Entering Initial Settings 1) At the Installation Setup 1 menu, press the cursor pad to select Key Beep. (Key Beepturns on or off the buzzer which sounds whena key is pressed.) 2) Press the cursor pad to select OFF or ON. 3) Select Hdg Sensor. 4) Select type of heading sensor connected to t h ...