Furuno 1761 MARK-3 Radar Detector User Manual
Contents
1. esses 2 4 P Plotting 2 11 Piloting tmr 2 11 POWER Key die ehe eda 2 2 Power on off 2 2 R Range 2 2 Range 2 5 Rarige ririgs 2 5 5 SAR ein attenti datae 3 2 ISI 2 2 Shadow Sectors 3 2 Side lobe Echoes 3 1 8 2 2 ae Laak 2 2 System configuration vii T ree reget eret 2 2 Troubleshooting 4 2 V VRM 2 5 WAtChmar 2 10 2 ZOON e 2 6 IN 12. 1002 OPERATOR S MANUAL MARINE RADAR MODEL 1761 MARK 3 p FURUNO ELECTRIC CO LTD NISHINOMIYA JAPAN FURUNO ELECTRIC CO LTD 9 52 Ashihara cho Nishinomiya Japan Telephone 0798 65 2111 Telefax 0798 65 4200 All rights reserved _ Printed in Japan PUB No OME 34810 YOSH MODEL 1761 MARK 3 Your Local Agent Dealer FIRST EDITION AUG 1998 D JUL 10 2001 00080835200 A SAFETY INSTRUCTIONS A DANGER Stay away from transmitting antenna The radar antenna emits microwave radiation which can be harmful to the human body particularly the eyes Never look directly into the antenna radiator from a distance of less than 1 m when the radar is in operation Radio Frequency Radiation Hazard The radar antenna emits electromagnetic radio frequency RF energy which can be harmful particularly to your eyes Never look directly into the antenna aperture from a close distance while the radar is in operation or expose yourself to the transmitting antenna at a close distance Distances at which RF radiation levels of 100 and 10 W m exist are given in the table below Note If the antenna unit is installed at a close distance in front of the wheel house your administration may require halt of transmission within a certain sector of antenna revolution This is possible Ask your FURUNO representative or dealer to provide this feature Distance to Distan
3. 1 PRINCIPLE OF OPERATION 1 1 What is Radar retten 1 1 1 2 How Ships Determined Position Before 1 1 1 3 How Radar Determines Range 1 1 1 4 How Radar Determines Bearing 1 1 1 5 Radar Wave Speed and Antenna Rotation Speed 1 1 1 6 The Radar Display 1 1 2 OPERATION 2 1 Control Description 2 1 2 2 Turning the Radar On Off 2 2 2 3 cote ete cree cen ai 2 2 2 4 Stand by 2 2 2 5 Selecting the Range 2 2 2 6 Adjusting Picture Brilliance 2 2 2 7 Adjusting Receiver Sensitivity 2 2 2 8 Adjusting the A C SEA Control reducing sea clutter 2 3 2 9 Adjusting the A C RAIN Control reducing rain clutter 2 4 2 10 Adjusting FTO session epe irte tense 2 4 2 11 Turning the Radar Receiver 2 4 2 12 Erasing the Heading Marker 2 4 2 13 Select the Cursor Data Display 2 5 2 14 Turning the Range Ring On Off 2 5 2 15 Measuring the Range 2 5 2 16 Measuring the Bearing 2 5 2 17 Shifting and Zooming the Display la rU P 2 6 2 18 Menu Operation 2 7 2 19 Echo ue cereo eii 2 8 2 20 Suppressing Radar Interference 2 8 2 21 Adjusting Control Panel Brilliance 2 8 2
4. cation to take a closer look at an area of in terest without changing the range 1 Operate the trackball to place the cursor on the target you want or area you want to zoom 2 Press the SHIFT ZOOM key The indi 2 18 Menu Operation cation ZOOM appears and brinks 3 To turn off the zoom press the SHIFT menu consisting of 9 items mostly con ZOOM key again or change the range tains less often used functions which once preset do not require regular adjustment To open or close the menu press the MENU Normal display key You can select menus by using the Place cursor where desired trackball then select item with the RANGE key Note Current selections shown in reverse x video Cursor Press the nA key MENU SEL MENU BY TRKBALL ITEMS WITH RANGE KEY SHIFT zoom gt ECHO STRETCH ON OFF REJECT OFF PANEL DIMMER 01 2 4 PLOT INTVL 30S 1M 3M 6M PLOT BRILL HIGH RANGE NM 34 9 15 SET WITH 6 12 24 36 E RING oak WP Display shifts Display magnifies 7 WATCHMAN 5M 10M 20M 8 NAV DATA ON 9 EBL CURSOR TRUE REL Figure 2 8 Shifting and zooming the display Figure 2 9 MENU Display Table 2 1 Menu Description Menu Function Factory setting Activates and releases the echo stretch function which stretches OFF ECHO SIRE LGH echoes lengthwise for better distance INTERFERENCE REJECTION Reduces or eliminates rada
5. clear up the picture or reduce clutter caused by rain or snow e Range resolution is a measure of the ca pability of a radar to display as separate pips the echoes received from two targets which are on the same bearing and are close together radially With reduction in the gain setting the echoes may be made to appear as separate pips on the display When sailing or cruising in crowded re gions a slight reduction in gain often helps to clear up the picture This should be done carefully otherwise weak targets may be missed Echoes from ships inside a squall or storm may be obscured if the gain is at its nor mal setting since the clutter may have masked but not completely echoes from the targets Note In all cases return the gain to its origi nal position after any temporary reduction is no longer required 2 8 Adjusting the A C SEA Control reducing sea clutter Echoes from waves can be troublesome cov ering the central part of the display with ran dom signals known as sea clutter The higher the waves and the higher the antenna above the water the further the clutter will extend Sea clutter appears on the display as many small echoes which might affect radar performance See the left hand figure in Figure 2 2 When sea clutter masks the picture adjust the A C SEA control to reduce the clutter How the A C SEA control works The A C SEA control reduces the amplifi cation of echoes at sh
6. 22 Selecting Ranges 2 9 2 23 EBL Cursor Bearing Reference 2 9 2 24 Guard Alarm 2 9 2 25 2 10 2 26 PIU sicrie 2 11 2 27 Navigation Data Display 2 11 3 FALSE ECHOES 31 Multiple Echoes 3 1 3 2 Side lobe Echoes 3 1 3 3 Indirect Echoes 3 2 3 4 Blind and Shadow Sectors 3 2 3 5 SART Search and Rescue Transpobder isses 3 3 4 MAINTENANCE 4 TROUBLE SHOOTING 4 1 Preventive Maintenance 4 1 4 2 Replacing the Fuse 4 1 4 3 Troubleshooting 4 2 4 4 Life Expectancy of Magnetron 4 3 SPECIFICATIONS SP 1 INDEX s IN 1 MENU TREE MENU KEY ECHO STRETCH ON OFF REJECT OFF ON PANEL DIMMER 0 1 2 3 4 PLOT INTVL CONT 305 1M 3M 6M PLOT BRILL LOW 4HIGH RANGE NM set with RING 1 4 172 3 4 1 1 5 2 3 4 6 8 12 16 24 48 WATCHMAN OFF 5M 10M 20M 8 NAV DATA ON OFF EBL CURSOR TRUE REL uf On TE co TABLE OF CONTENTS INDICATION MARKER Plotting P 2 11 Elapsed time P 2 11 Plotting interval P 2 11 MAG or GYRO BEARING option Heading marker P 2 4 Tuning indicator P 2 11 Echo stretch P 2 8 Range 2 2 _ _ly 12 N
7. 7 To cancel both the guard zone and the audible alarm press and hold down the GUARD key for three seconds Note 1 When the range is less than the half of the guard zone range the guard zone dis appears from the screen and UP RANGE indication appears If this happens select a range which will again display the guard zone on the screen 2 9 Note 2 A target echo does not always mean alandmass reef ships or surface objects but can imply returns from sea surface or pre cipitation As the level of these returns varies with environment the operator should prop erly adjust the A C SEA A C RAIN FTC and GAIN to be sure target echoes within the guard zone are not overlooked by the alarm system Asterisk blinking x Guard zone to set Drag cursor here 1 Mentally create the guard zone to set 2 Drag cursor to top left corner of zone and press GUARD Drag cursor here 4 Guard zone completed 3 Drag cursor to bottom right corner of zone and press GUARD Figure 2 11 Setting Guard Zone Auto In Out Alarm When the guard zone is set completely the radar starts searching for targets inside the guard zone for 8 to 12 seconds The indica tion GUARD appears during this period Case 1 When there are targets inside the zone the alarm zone is automatically set to Auto Out Alarm mode and the indication GUARD is replaced by G OUT The au dible alarm so
8. frequency radio radiation which can be harmful particularly to your eyes Never look directly into the scanner from a distance of less than two feet when the radar is in operation as you could injure the cornea of your eyes Always make sure the radar is set to stand by or is turned off before starting work on the scanner unit 4 1 Preventive Maintenance Regular maintenance is important for good performance Always keep the equipment as free as possible from dirt dust and water splashes Make sure all screws securing the components are properly tightened A maintenance program should be estab lished and should at least include the items listed in Table 4 1 4 2 Replacing the Fuse The fuse on the rear panel of the display pro tects the equipment against reverse polarity of ship s mains overcurrent and equipment fault If the fuse blows find the cause before replacing it Never use an incorrect fuse serious damage to the equipment may re sult and void the warranty 12V 10A fuse 24 32V fuse CAUTION Use the proper fuse Use of a wrong fuse can result in equipment damage Table 4 1 Hecommended maintenance program scanner unit Period Item Check point Remarks 3 to 6 Exposed Check for corroded or loosened Sealing compound may be used months nuts and nuts and bolts If necessary instead of paint Apply a small bolts on clean and repaint them thickly amount of grease between nuts Re
9. pur chaser any purchaser who has doubts about his or her technical abilities may wish to have the unit installed by a FURUNO representa tive or other qualified technician The impor tance of a through installation can not be overemphasized We would appreciate hearing from you the end user about whether we are achieving our purposes Thank you for considering and purchasing FURUNO equipment Features Your radar has a large variety of functions all contained in a remarkably small cabinet The main features of the MODEL 1761 3 are e Traditional FURUNO reliability and qual ity in a compact lightweight and low cost radar e Durable brushless antenna motor e On screen alphanumeric readout of all op erational information e Standard features include EBL Electronic Bearing Line VRM Variable Range Marker Guard Alarm Display Off Cen ter and Echo Trail e Watchman feature periodically transmits the radar to check for radar targets which may be entering the alarm zone e Ship s position in latitude and longitude range and bearing to a waypoint and ship s speed heading course can be shown in the bottom text area Requires a navigation aid which can output such data in IEC 61162 format e Zoom feature provided TABLE OF CONTENTS FOREWORD erret lii MENU TREE V TABLE OF CONTENTS BY INDICATION MARKER vi SYSTEM CONFIGURATION
10. return 1 5 Radar Wave Speed and Scanner Rotation Speed Note that the speed of the radar waves out to the target and back again as echoes is extremely fast compared to the speed of ro tation of the scanner By the time radar ech oes have returned to the scanner the amount of scanner rotation after initial transmission of the radar pulse is extremely small 1 6 The Radar Display The range and bearing of a target is displayed on what is called a Plan Position Indicator PPI This display is essentially a polar dia gram with the transmitting ship s position at the center Images of target echoes are re ceived and displayed at their relative bear ings and at their distance from the PPI center With a continuous display of the images of targets the motion of the transmitting ship is also displayed 1 1 1 2 5 Heading marker Range and bearing of a target relative to own ship are readable on the Own ship radar in center A Bird s eye view of situation B Radar picture of A Figure 1 1 How radar works 2 1 Control Description Turns power on Press together with STBY TX key to turn power off Alternates between stand by and transmit Lights in green to show the Adjusts the brightness of the screen 7 gt radar is in the echonomy stand by mode Selects radar range The and touchpads select hig
11. whistles fire a shot or strike a bell The time between the origination of the sound and the returning of the echo indicated how far the ship was from the cliffs or the shore The direction from which the echo was heard indicated the rela tive bearing of the shore 1 3 How Radar Determines Range Radar determines the distance to the target by calculating the time difference between the transmission of a radar signal and the recep tion of the reflected echo It is a known fact that radar waves travel at a nearly constant speed of 162 000 nautical miles per second Therefore the time required for a transmitted signal to travel to the target and return as an echo to the source is a measure of the dis tance to the target Note that the echo makes a complete round trip but only half the time of travel is needed to determine the one way distance to the target This radar automati cally takes this into account in making the range calculation 1 4 How Radar Determines Bearing The bearing to a target found by the radar is determined by the direction in which the ra dar scanner antenna is pointing when it emits an electronic pulse and then receives a re turning echo Each time the scanner rotates pulses are transmitted in the full 360 degree circle each pulse at a slightly different bear ing from the previous one Therefore if one knows the direction in which the signal is sent out one knows the direction from which the echo must
12. 505 1 12 2 v Number of Rings 4 1 Markers Heading Line Bearing Scale Range Rings Variable Range Marker VRM Electric Bearing Line EBL Tuning Bar Cursor Alarm Zone Waypoint Mark navigation input required North Mark heading sensor input required 4 2 Alphanumeric Indications Range Range Ring Interval Interference Rejection IR Stand by ST BY Radar Alarm G IN G OUT G ACKN Range Bearing and Latitude Longitude of Cursor Echo Stretch ES Echo Plot PLOT Plot Elapsed Time Navigation Data navigation input required Heading HDC heading sensor input required 4 3 Input Data 0183 Ver 1 5 2 0 current loop Own ship s position GGA gt RMA gt RMC gt GLL accept GLL in NMEA Version1 5 only Speed RMA gt RMC gt VTG gt VHW Heading True HDT HDG gt HDM gt VHW gt VHW Heading Magnetic HDM gt HDG gt HDT gt VHW gt VHW Course True RMA gt RMC gt VTG Course Magnetic VTG gt RMC gt RMA Waypoint Range Bearing RMB gt BWC gt BWR Loran time difference RMA gt GLC gt GTD 1 calculated by magnetic drift 4 4 Output Data NMEA 0183 Version 1 5 2 0 RS 422 5 ENVIRONMENTAL CONDITION 5 1 Ambient Temperature Antenna Unit 25 C to 70 C Display Unit 15 C to 55 C 5 2 Relative Humidity 95 or less at 40 C 5 3 Waterproofing Antenna Unit IPX6 Display Unit IPX4 6 POWER SUPPLY amp POWER CONSUMPTION 6 1 Power Supply 12 32 VDC 10 2 to 40 0 VDC 58 W appr
13. 8 12 16 24 36 48 ESI 5 2100 Hz 0 08 us Memor oss up poore l 1 3 Range Resolution 41 m 1 4 Bearing Discrimination 2 9 1 5 Minimum Range 39 m 0 25 NM range 1 6 Bearing Accuracy Within 1 1 7 Range Ring Accuracy 0 9 96 of range or 8 m whichever is the greater 2 ANTENNA UNIT 2 1 Radiator Slotted waveguide array 2 2 Polarization Horizontal 2 3 Antenna Rotation Speed 24 rpm or 48 rpm nominal 2 4 Radiator Length 100 cm XN 10A 2 5 Horizontal Beamwidth 2 49 2 6 Vertical Beamwidth 27 2 7 Sidelobe Attenuation Within 20 of main lobe less than 24 dB Outside 20 of main lobe less than 30 dB 3 TRANSCEIVER MODULE 3 1 Frequency 9410 MHz 30MHz X band 3 2 Modulation PON 3 3 Peak Output Power 4 kW nominal 3 4 Modulator FET Switching Method 3 5 Intermediate Freguency 60 MHz 3 6 Tuning Automatic 3 7 Receiver Front MIC Microwave IC 3 8 Bandwidth Tx pulselength 0 08 us and 0 3 us 7 MHz Tx pulselength 0 8 us 3 MHz 3 9 Duplexer Circulator with diode limiter SP 1 E3481S01B 4 DISPLAY UNIT 4 1 Indication System PPI Daylight display raster scan 8 tones in monochrome 4 2 Picture Tube 7 inch rectangular monochrome CRT Effective display area more than 100 mm 4 3 Range Range Interval Number of Rings Range NM 0 25 05 075 1 15 2 3 4 6 8 12 1624 48 Ring interval NM Jo 125 0 125 025 526 0
14. M Range ring interval P 2 2 3 0 Shift or Zoom P 2 6 Watchman P 2 10 7 7 A 2 Guard zone P 2 9 4 7 Cursor P 2 5 6 EBL1 bearing P 2 6 m vpn 115 01 PLOT 3M MM au LT 18 25 ES Vip Guard alarm P 3 4 FTC P 2 4 WATCHMAN GUARD n FTC IR de Interference rejector P 2 8 EBL P 2 6 Range ring P 2 3 2 5 lau L 9 05 NM 2 62 NM Cursor data P 2 5 Bearing Range or VRM range P 2 5 Latitude Longitude vi SYSTEM CONFIGURATION Scanner Unit FUR UNO Navigation IEC 61162 In Out device ue dU MM DE Display Unit Gyro Converter RDP 099 compass AD100 Intergrated Heading Loco Sensor PG 1000 12 VDC 10 24 32 VDC 5A 12 24 32 VDC vii XN10A RSB 0070 065 External Alarm Buzzer OP03 21 Rectifier RU 3423 115 230 VAC 1 PRINCIPLE OF OPERATION 1 1 What is Radar The term RADAR is an acronym meaning RAdio Detection And Ranging Although the basic principles of radar were developed dur ing World War echoes as an aid to naviga tion is not a new development 1 2 How Ships Determined Position Before Radar Before the invention of radar when running in fog near a rugged shoreline ships would sound a short blast on their
15. ange Press the RANGE key The range and range ring interval appear at the top left cor ner on the display Tips for selecting the range When navigating in or around crowded harbors select a short range to watch for possible collision situation e If you select a lower range while on open water increase the range occasionally to watch for vessels that may be heading your way 2 6 Adjusting Picture Brilliance The BRILL key adjusts the brilliance of the radar picture in eight levels Press the BRILL key to set the brilliance level 2 7 Adjusting Receiver Sensitivity The GAIN control adjusts the sensitivity of the receiver It works in precisely the same manner as the volume control of a broadcast receiver amplifying the signals received The proper setting is such that the back ground noise is just visible on the screen you set up noise is just visible on the screen If you set up for too little sensitivity weak echoes may be missed On the other hand excessive sensitivity yields too much back ground noise strong targets may be missed because ofthe poor contrast between desired echoes and the background noise on the dis play To adjust receiver sensitivity transmit on long range and adjust the GAIN control so back ground noise is just visible on the screen Tips on adjusting GAIN certain circumstances it may be useful to reduce the gain slightly to improve range resolution
16. ate the watchman mode The indication WATCH MAN appears and the radar transmits for one minute and then turns to stand by and lights Note The antenna radiator does not rotate in the ECHONOMY stand by mode How ever the radiator rotates continuously dur ing the watchman mode 6 The radar automatically starts transmit ting after the time selected at step 4 has passed It transmits for one minute ap proximately and examines the guard zone for change a If the condition is unchanged the ra dar automatically returns to stand by again and continues operating in the watchman mode b If the condition differs from the previ ous one the radar sounds an audible alarm cancels the watchman mode and transmits continuously 7 To cancel the watchman mode manually press any key 2 26 Plotting This function plots the movement of other ships relative to your own ship Press the PLOT A C RAIN control to start plotting The indication PLOT and a timer appear at the top right hand corner of the screen and movement of all targets is plot ted The timer counts up from 0 01 to 99 59 whereupon the timer indication freezes but plotting continues Targets initially are up dated every 15 seconds However you can select intervals of 30 seconds 1 minute 3 minutes or 6 minutes through the MENU dis play Refer to Chapter 3 The plotting inter val except for 15 seconds appears to th
17. ce to Radiator 100 W m 10 W m MODEL type point point 1761 MK 3 XN10A 0 2 m Worst case 3 0 m A DANGER A WARNING Before turning on the radar Use the proper fuse make sure no one is near the scanner unit Fuse rating is shown in the chapter 5 Use of a wrong fuse can result in equipment Prevent the potential risk of damage someone begin struck by the rotating antenna and exposure to RF radiation hazard Do not operate the equipment with wet hands Electrical shock can result A WARNING CAUTION Do not open the eguipment Do not use the eguipment for other than its intended purpose Improper handling can result in electrical shock Only gualified personnel shold Use ofthe eguipment as a stepping stool work inside the equipment for example can result in personal injury or eguipment damage Do not disassemble or modify the eguipment No one navigation device should ever be solely replied upon for the navigation of Fire electrical shock or serious injury can a vessel result Always confirm position against all available Turn off the power immediately if water aids to navigation for safety of vessel and leaks into the eguipment or the eguip crew ment is emitting smoke or fire Continued use of the equipment can cause fire or electrical shock Two warning labels are attached to the display unit and scanner unit Do not remove these labels n If labels are peeling off or are ill
18. dia tion escapes on each side of the beam called side lobes If a target exists where it can be detected by the side lobes as well as the main lobe the side lobe echoes may be represented on both sides of the true echo at the same range as shown in Figure 4 2 Side lobes show usually only at short ranges and from strong targets They can be reduced through careful reduction of the sensitivity or proper adjustment of the A C SEA Main lobe True echo Side lobe Sprious target Antenna Figure 3 2 Side lobe echoes 3 1 3 3 Indirect Echoes Indirect echoes may be returned from either a passing ship or returned from a reflecting surface on your own ship for example a stack In both cases the echo will return from a legitimate contact to the scanner by the same indirect path The echo will appear on the same bearing of the reflected surface but at the same range as the direct echo Figure 4 3 illustrates the effect of an indirect echo Indirect echoes may be recognized as fol lows they usually occur in a shadow sector they appear on the bearing of the obstruc tion but at the range of the legitimate con tact when plotted their movements are usu ally abnormal and their shapes may indicate they are not di rect echoes Heading marker Direct path EN Target Indirect path Obstruction Scanner mast funnel True Indirect echo echo Indirect echo echo F
19. e MENU key to open the menu 2 Operate the trackball to select 3 PANEL DIMMER 3 Press the RANGE key to select level de sired 4 Press the MENU key again to erase the menu 2 22 Selecting Ranges This radar has 14 ranges some which you may not require You can select or deselect ranges as follows 1 Press the MENU key to open the menu 2 Operate the trackball to select 6 RANGE 3 Press the RANGE key to place the un derline under the range you want to se lect or deselect 4 Press the RING key to select or dese lect 5 Repeat step 4 and 5 Maximum number of ranges is all ranges Minimum number of ranges is two 2 23 EBL Cursor Bearing Reference EBL and cursor bearing can be displayed relative to own ship s heading Relative or with reference to North True Note Magnetic compass or gyrocompass connection required for true bearing 1 Press the MENU key to open the menu 2 Operate the trackball to select 9 EBL CURSOR 3 Press the RANGE key to select TRUE or REL Relative 2 24 Guard Alarm The alarm allows the operator to set the de sired range 0 to maximum range and bear ing 0 to 360 degrees for a guard zone called Auto In Out alarm When ships islands land masses etc go into or go out of the guard zone an audible alarm sounds to call the operator s attention Before setting the alarm be sure the GAIN control is pro
20. e right of the indication PLOT If the range is changed during plotting plot ting begins anew with the newly selected range To cancel plotting press the PLOT key Plotting Interval 30 sec 1min 3min 6min PLOT PLOT 3M 0 25 18 25 Timer Figure 2 14 Plotting Indications Plot Brilliance The brilliance of plotted echoes is selectable through the MENU display Press the MENU key and select 5 PLOT BRILLIANCE 2 27 Navigation Data Display Navigation data can be displayed on the screen if your radar receives navigation in put form a Loran C NNSS satellite naviga tor or GPS navigator whose output formats is IEC 61162 or FURUNO CIF Data displayable include own ship s position in lati tude and longitude or Loran C time differ ences TDs bearing and range to a waypoint selected on the nav aid own ship s speed heading and course In addition if a heading sensor or gyrocompass is also con nected a line connects a waypoint selected on navaid denoted by a dashed ring with the own ship s position To return the navigation data display on or off press the MENU key and select 8 NAV DATA To display TDs instead of L L press the GAIN control Press the control again to restore L L 2 11 If the output format is FURUNO CIF jumper wire must be connected to JUP1 on the SPU Board in the display unit Note that for CIF format the bearing
21. e ways by the range rings by the cursor and by the VRM Variable Range Marker Measuring range by range rings Count the number of rings between the cen ter of the display and the target Check the range ring interval and judge the distance of the echo from the inner edge of the nearest ring To turn the rings on or off press the RING key Measuring range by cursor Operator the trackball to place the cursor in tersection on the inside edge of the target echo The range to the target as well as the bearing appears at the bottom of the display Measuring by VRM 1 Press the VRM key to display a VRM The VRM is the dotted ring 2 Place the VRM on the inside edge of the target by operating the trackball 3 Pressthe VRM key again to fix the VRM to the position 4 Checkthe range readout to find the range to the target To erase the VRM press and hold down the VRM key for about three seconds Range ___ 6 0 NM Range ring 2 0 interval Target VRM Cursor C 315 1 R VRM 4 0 4 0 NM VRM Cursor range Figure 2 5 Measuring Range by the Cursor and the VRM Unit of range measurement You can display the range readouts of the VRM and the cursor in nautical miles or kilo meters This is done at installation 2 16 Measuring the Bearing There are two ways to measure the bearing to a target by the cursor and by the EBL Electronic Bearing Range Measuring bearing b
22. easuring bearing Bearing measurements of smaller targets pips are more accurate the center of larger target pips is not as easily identi fied 2 6 Bearings of stationary or slower moving targets are more accurate than bearings of faster moving targets To minimize bearing errors keep echoes in the outer half of the picture by chang ing the range scale angular difference becomes difficult to resolve as a target approaches the center of the display 2 17 Shifting and Zooming the Display The SHIFT ZOOM key has two functions display shifting and display zoom Each time the key is pressed the function changes in the following sequence m Normal gt gt Shift Zoom Figure 2 7 SHIFT ZOOM key sequence Shift The own ship s position can be shifted to any position within the current range The primary advantage of the shifted display is that for any range setting the view ahead of your own ship can be extended without changing the range Place the cursor on area you wish to shift to the screen center and then press the SHIFT ZOOM key The indication SHIFT appears To restore normal operation press the key twice Note If the cursor is not within the current range when the key is pressed an audible beep sounds and the outermost range ring blinks twice even if the range rings are off Zoom The zoom feature allows you to double the area between own ship and an arbitrary lo
23. egible contact Do not place liquid filled containers on a FURUNO agent or dealer the top of the equipment Display Unit gt N WARNING N Fire or electrical shock can result if a liquid Name Warning Label 1 avoid electrical shock do A A 86 003 1011 0 remove cover No user serviceable spills into the equipment Cade ne 100 236 230 parts EA ROBO 9 9 UEAYZIMOZIAa 5 E amp BU WTR EW AMBIT BEB AS BSS HV A SHSECRATS lt Scanner Unit gt Name Radiation Warning WARNING Radiation hazard Only qualified Label personnel should work inside scanner Type 03 142 3201 0 ae Code no 100 266 890 VETOT TCE FOREWORD Congratulations on your choice of the FURUNO MODEL 1761 MARK 3 Marine Ra dar We are confident you will see why the FURUNO name has become synonymous with quality and reliability For over 50 years FURUNO Electric Com pany has enjoyed an enviable reputation for innovative and dependable marine electron ics equipment This dedication to excellence is furthered by our extensive global network of agents and dealers Your radar is designed and constructed to meet the rigorous demands of the marine en vironment However no machine can per form its intended function unless properly installed and maintained Please carefully read and follow the recommended proce dures for installation operation and mainte nance While this unit can be installed by the
24. en and the echoes are doubled lengthwise To turn off the echo stretch select OFF on the MENU display Note 1 This function magnifies not only tar gets but also sea clutter and radar interfer ence are properly adjusted before activating the echo stretch Note 2 This function is inactivate on short ranges that is 0 25 to 1 nautical miles ES appears in reverse video when the echo stretch is turned on in those ranges 2 20 Suppressing Radar Interference Radar interference may occur when near an other shipborne radar operating in the same freguency band as your radar Its on screen appearance is many bright dots either scat tered at random or in the form of dotted lines extending from the center or the edge to the edge or the center of the display Fig ure 2 11 illustrates interference in the form of curved spokes Interference effects are distinguishable from normal echoes because they do not appear in the same place on suc cessive rotations of the scanner Figure 2 10 Radar interference 1 Press the MENU key to open the menu 2 Operate the trackball to select 2 RE 3 Press the RANGE key to select ON Factory setting is ON The indication IR appears at the upper right hand side of the screen Press the MENU key again to erase the menu display 2 21 Adjusting Control Panel Brilliance Adjusts the backlighting of the front panel in five steps 1 Press th
25. fined waters However with the circuit activated the re is less sensitive Therefore turn off the circuit when its function is not required 2 11 Tuning the Radar Receiver The radar receiver is tuned automatically each time you turn on the power thus there is no front panel control for adjustment of the receiver To show the automatic tuning cir cuit is working a tuning bar displays tuning condition 2 12 Erasing the Heading Marker The heading marker may occasionally mask a target To view the target you can tempo rarily erase the heading marker by pressing and holding down the GAIN HM OFF con trol Release the control to re display the markers Heading marker Figure 2 4 Heading marker 2 13 Select the Cursor Data Display When connecting with NAV IEC61162 for mat and gyro converter IEC61162 or AD 10 format this radar can show the cursor position by Latitude longitude at bottom of screen Each time pressing HM OFF key the data will change from Range Bearing to Latitude longitude and vice versa When the cursor position is displayed by Lati tude Longitude pressing the HM OFF key outputs L L data of the cursor position TLL to the plotter Then Range Bearing are dis played instead of L L 2 14 Turning the Range Ring On Off When range rings obscures a target you can erase them by pressing the RING key 2 15 Measuring the Range You can measure the range to a target thre
26. her and lower range respectively Selets items during the menu display Shifts the display turns the zoom 1 function on and restores normal picture in that order SHIFT 7 zoom RING 2 OPERATION r Control Adjusts sensitivity of radar receiver Switch 1 Temporarily erases heading marker liialda E 2 Change cursor data from OFF WCSEA 8 8 to L L and vice versa SEY Control Reduces sea clutter caused Economy PUSH PLOT by waves cm oo Switch Turns on off the radar alus gt target plotting PUSH FTC RANGE EBL VRM Turns the Electronic Bearing GUARD MENU Control Reduces rain clutters Switch Suppresses heavy precipitation Turns the fixed range rings on and off Turns the Variable Range Marker VRM on and off a Line EBL on and off Turns on and off the guard zone alarm Turns the menu display on and off Trackball 1 Shifts cursor EBL and VRM 2 Sets guard zone 3 Selects items and options on menu 4 Shifts origin of EBL and VRM Figure 2 1 Control panel 2 1 2 2 Turning the Radar On Off After confirming there are no crew near the scanner unit press the POWER key to turn on the power The front panel will light up The magnetron takes about two minutes and thirty seconds to warm up before the radar can be oper ated The time remaining fo
27. igure 3 3 Indirect echoes 3 2 3 4 Blind and Shadow Sectors Funnels stacks masts or derricks in the path of antenna may reduce the intensity of the radar beam If the angle subtended at the antenna is more than a few degrees a blind sector may be produced Within the blind sector small targets at close range may not be detected while larger targets at much greater ranges may be detected See Figure 4 4 Vessel taller Mast etc in harf path of radar What beam What Blind sector Size of blind sector depends on target sie and range Figure 3 4 Blind and shadow sectors 3 5 SART Search and Rescue Transponder A Search and Rescue Transponder SART may be triggered by any X Band 3 cm ra dar within a range of approximately 8 n miles Each radar pulse received causes it to trans mit a response which is swept repetitively across the complete radar frequency band When interrogated it first sweeps rapidly 0 4 us through the band before beginning a rela tively slow sweep 7 5 us through the band back to the starting frequency This process is repeated for a total of twelve complete cycles At some point in each sweep the SART frequency will match that of the inter rogating radar and be within the pass band of the radar receiver If the SART is within range the frequency match during each of the 12 slow sweeps will produce a response on the radar display thus a line of 12 dots equal
28. ly spaced by about 0 64 nautical miles will be shown When the range to the SART is reduced to about 1 nm the radar display may show also the 12 responses generated during the fast sweeps These additional dot responses which also are equally spaced by 0 64 nm will be interspersed with the original line of 12 dots They will appear slightly weaker and smaller than the original dots Screen A When SART Screen B When SART is distant i is close Lines of 12 dots are displayed in concentric arcs Echo of SART Radar antenna beamwidth Echo of SART Position of SART Own ship s position Own ship s position Position of SART SART mark length Radar receiver A bandwidth A Low speed sweep signal Sweep start High speed sweep signal Figure 3 5 SART display ANN NN SENT SN Showing SART marks on the radar display To show the SART marks only on the radar display detune the radar receiver manually This erases or weakens all normal radar ech oes but the SART marks are not erased be cause the SART response signal scans over all frequencies in the 9 GHz band When the radar approaches the SART in operation the SART marks will enlarge to large arcs blur ring a large part of the screen Reduce the sensitivity and adjust the sea clutter control of the radar Summary to detect SART response 1 Use range scale of 6 or 12 nm as the spacing between the SART response
29. measurement method Magnetic or True does not appear for bear ing to waypoint data Own ships position LL MAG 115 0 wem WP 1 pna Bs latitude and longitude Ship s heading 2 12 34 38 99S 135 19 22E HD 115 0 EBL 48 1 R 6 0 NM 171 6 M CRS 9151 R 9 05 NM GUARD IR Waypoint Range to Waypoint Bearing to Waypoint M Magnetic T True M or T appear in CIF format Ship s speed Ship s course Figure 2 15 Navigation Data on the Screen 3 FALSE ECHOES Occasionally false echoes appear on the screen at positions where there is no target In some cases the effects can be reduced or eliminated The operator should familiarize himself or herself with the appearance and effects of these false echoes so as not to confuse them with echoes from legitimate contacts 3 1 Multiple Echoes Multiple echoes occur when a short range strong echo is received from a ship bridge or breakwater A second a third or more ech oes may be observed on the display at double triple or other multiples of the actual range of the target as shown in Figure 4 1 Multiple reflection echoes can be reduced and often removed by decreasing the sensi tivity or properly adjusting the A C SEA True echo Own ship Multiple echo Figure 3 1 Multiple echoes 3 2 Side lobe Echoes Every time the scanner rotates some ra
30. ort ranges where clut ter is the greatest and progressively increases amplification as the range in creases so amplification will be normal at those ranges where there is no sea clutter Adjusting the A C SEA control The proper setting of the A C SEA should be such that the clutter is broken up into small dots and small targets become distinguish able If the control is set too low targets will be hidden in the clutter while if itis set too high both sea clutter and targets will disappear from the display In most cases adjust the control until clutter has disappeared to lee ward but a little is still visible windward 1 Confirm that the sensitivity is properly ad justed and then transmit on short range 2 Adjustthe A C SEA control so small tar gets are distinguishable but some clutter remains on the display Sea clutter at display center A C SEA control adjusted sea clutter suppressed Figure 2 2 How to adjust the A C SEA control Tip for adjusting the A C SEA A common mistake is to over adjust the cir cuit so all the removed As an example set up for maximum A C SEA You will see how the center of the display becomes dark This dark zone can be dangerous targets may be missed especially if the sensitivity is not properly adjusted Always leave a little clut ter visible on the display to be sure weak echoes will not be suppressed If there is no clutter visible on the display turn off the ci
31. ox 6 2 Voltage and Current XN 10A 24rpm 12 VDC 4 5 A 24 VDC 2 0 A 32 VDC 2 0A 6 3 Power Consumption XN 10A 24rpm 70 W to 90 W 100 kt SP 2 E3481S01B 7 COATING COLOR 7 1 Display Unit Panel N3 0 Chassis 2 5GY5 1 5 7 2 Antenna Unit N9 5 8 COMPASS SAFE DISTANCE 8 1 Display Unit Standard 0 50m Steering 0 40 m 8 2 Antenna Unit Standard 1 00m Steering 0 75 m SP 3 E3481S01B Index A A C RAIN 2 4 SEA control 2 3 B Bearing measurement 2 5 Blind sectors 3 2 2 2 2 8 BRILL inicio eas 2 2 E 2 5 Echo Stretch 2 8 Economy mode 2 2 F gii 4 1 G GAIN iii rise TT 2 2 Guard alarm 2 9 Guard key i ieee 2 9 Guard zone 2 9 H Heading marker sss 2 4 Indirect echoes 3 2 Interference 2 8 M 4 3 4 1 Multiple Echoes 3 1 Men I66G cce c rera rh ir rns V N Navigation data 2 11 NOISE i iva TRITT TELS 3 8 North marker
32. perly adjusted because the au dible alarm sounds when the fifth or more level quantization echoes go into or go out of the guard zone 1 Mentally create the guard zone you want to display on screen See Figure 2 12 2 Set upper lower left edge of the guard zone with the cursor and press the GUARD key The indication GUARD asterisk blink ing appears at the upper right hand side of the screen See Figure 2 12 2 The asterisk indicates the guard zone is par tially set but the alarm function has not been actuated It disappears once the guard zone is set completely 3 Moving the trackball clockwise set the lower upper right edge of the guard zone The guard zone now appears on the display and alarm function has been actuated See Figure 2 12 3 Note To create a 360 degree guard zone rotate the cursor counterclockwise instead of clockwise 4 Press the GUARD key again The as terisk disappears and the alarm function is actuated after three to five antenna scannings and then the indication GUARD is replaced by G IN or G OUT 5 Any ships landmasses etc coming into or going out of the guard zone will trigger the audible alarm If the audible alarm sounds you can silence it by pressing the GUARD key When this is done the indi cation GUARD appears in reverse video 6 Press the GUARD key again to restore the audible alarm GUARD lights in nor mal video
33. place them if heavily and bolts for easy removal in corroded future scanner Check for dirt and cracks on Do not use plastic solvent radiator radiator surface Thick dirt should acetone for cleaning If you be wiped off with soft cloth need to remove ice from antenna dampened with fresh water If a unit use a wooden hammer or crack is found apply a slight plastic head hammer Crack on amount of sealing compound or the unit may cause water adhesive as a temporary ingress causing serious remedy then call for repair damages to internal circuits 6 months Display unit Check for tight connection and If corroded contact your dealer to 1 year connectors corrosion for replacement 4 1 4 3 Troubleshooting Table 4 2 contains simple troubleshooting procedures which you can follow to try to re store normal operation If you cannot restore normal operation do not attempt to check inside any unit of the radar system Any re pair work is best left to a qualified technician Table 4 2 Troubleshooting table If But Then you pressed the POWER key to turn on the radar the control panel does not light try adjusting the control panel back lighting on the OTHERS menu battery may have discharged check fuse in power cable nothing appears on the display or display contrast is poor try adjusting the brilliance characters are distorted request
34. r Cuit 2 3 2 9 Adjusting the A C RAIN Control reducing rain clutter The vertical beamwidth of the antenna is de signed to see surface targets even when the ship is rolling However by this design the unit will also detect rain clutter rain snow hail etc in the same manner as normal tar gets Figure 2 3 shows the appearance of rain clutter on the display Adjusting A C RAIN When rain clutter masks echoes adjust the A C RAIN control This control splits up these unwanted echoes into a speckled pat tern marking recognition of solid targets easier Appearance of rain clutter Figure 2 3 Effect of A C RAIN A C RAIN control adjusted rain clutter suppressed Note In addition to reducing clutter the A C RAIN control can be used in fine weather to clarify the picture when navigating in confined waters However with the circuit activated the receiver is less sensitive Therefore turn off the circuit when its function is not required 2 10 Adjusting FTC To suppress rain clutter from heavy storms or scattered rain clutter press the A C RAIN control FTC switch The FTC circuit splits up these unwanted echoes into a speckled pattern marking recognition of solid targets easier FTC appears at the top right hand corner of the display when the circuit is turned on 2 4 Note In addition to reducing clutter the FTC can be used in fine weather to clarify the pic ture when navigating in con
35. r interference ON Changes the plotting interval in five steps 30sec 1min 3min 6min and continuous Presets the ranges you want to use The preset ranges are in reverse video 1 With the RANGE key place the underline under the range you want to select or deselect Press the RING key to select or deselect Maximum number of ranges is all ranges Minimum number of range is two Turns on and selects the watchman interval Select interval 5min 10min or 20min with the RANGE key WATCHMAN Press the MENU key to activate the watchman mode The ECONOMY indication lights after the radar transmits for about 30 seconds NAV DATA Turns the navigation data display navigation input reguired on and off Selects the bearing measured by the EBL or cursor in true magnetic compass or gyrocompass connection reguired or relative bearing TRUE relative to the True North REL relative to the bow of the vessel EBL CURSOR BEARING 2 19 Echo Stretch Normally the reflected echoes from long dis tance targets appear on the screen as weaker and smaller blips even through they are com pensated by the radar s internal circuitry The Echo Stretch function magnifies these small blips 1 Press the MENU key to open the menu 2 Operate the trackball to select 1 ECHO STRETCH 3 Press the RANGE key to select ON The indication ES appears at the upper right hand side of the scre
36. r warm up of the magnetron appears at the center of the dis play counting down from 2 29 to 0 01 To turn off the radar press the POWER and TX key together 2 3 Transmitting After the power is turned on and the magne tron has warmed up the message ST BY Stand By appears at the center of the dis play showing the radar is ready to transmit However no targets will appear on the screen until the radar is transmitting by pressing the TX key TX is short for transmit In stand by the radar is available for use at anytime but no radar waves are being transmit 2 4 Stand by When you won t be using the radar for an extended period but you want to keep it in a state of readiness place it in stand by by pressing the TX key The display shows STBY default setting or goes into the economy mode You can select stand by condition on the menu Economy mode The CRT be set to automatically turn it self off when in stand by to reduce power consumption This feature is called the economy mode When the economy mode is on the ECONOMY indication under the TX key lights 2 5 Selecting the Range The range selected automatically determines the fixed range ring interval the number of fixed range rings pulselength and pulse rep etition rate for optimal detection in short to long ranges The range and ring interval ap pear at the top left corner of the display Selecting the r
37. s is about 0 6 nm 1125 m to distinguish the SART 2 Turn off the automatic clutter suppression 3 Turn off the Interference Rejector General remarks on receiving SART Radar range scale When looking for a SART it is preferable to use either the 6 or 12 nautical mile range scale This is because the total displayed length of the SART response of 12 or 24 dots may extend approximately 9 5 nautical miles beyond the position of the SART and it is necessary to see a number of response dots to distinguish the SART from other re sponses SART range errors When responses from only the 12 low fre quency sweeps are visible when the SART is at a range greater than about 1 nm the position at which the first dot is displayed may be as mush as 0 64 nm beyond the true po sition of the SART When the range closes so that the fast sweep responses are seen also the first of these will be no more than 150 meters beyond the true position 3 3 4 MAINTENANCE amp TROUBLESHOOTING This chapter tells you how to keep your ra dar in good working order Before reviewing this chapter please read the safety informa tion which follows A DANGER Turn off the power before performing any maintenance or troubleshooting procedure Hazardous voltages can shock burn or cause death Only qualified personnel totally famillier with electrical circuits should work inside the units RF RADIATION HAZARD The radar scanner emits high
38. service the radar has warmed up and you pressed the TX key to transmit the scanner does not rotate the problem may be in scanner unit Request service characters and indications are abnormal have a qualified technician check the set you have adjusted the gain with A C RAIN and A C SEA off neither noise nor targets appear indications and markers do neither indications nor markers appear noise and targets do check signal cable for damage check signal cable for damage the sweep radial line sweeping around the display is not synchronized with scanner rotation the problem may be in the scanner unit Request service there is no change in sensitivity request service a key is pressed nothing happens key may be faulty Request service 4 2 4 4 Life Expectancy of Magnetron The following table shows the life expectancy of the magnetrons Table 4 3 Life expectancy of magnetrons Magnetron Type Life expectancy MG5248 000 116 121 gt 3 000 hours Including stand by E3571 000 137 529 SPECIFICATIONS OF MARINE RADAR MODEL 1761 MARK 3 1 GENERAL 1 1 Indication System PPI Daylight display raster scan 8 tones in monochrome 1 2 Range Pulselength PL amp Pulse Repetition Rate PRR Range nautical miles _________________ pL __ 0 25 025 05 075 15 2 a 4 6
39. unds only on targets which go out of the zone or disappear See Figure 2 13 1 2 10 Note The audible alarm does not sound for the target originally existing the zone Case 2 When no targets exist inside the zone the alarm zone is automatically set to Auto In Alarm mode and the indication GUARD is replaced by IN The au dible alarm sounds only on targets which go into the zone See Figure 2 13 2 Dashed line no alarm 7 Guard zone IN ALARM OUT ALARM Figure 2 12 Auto In Out Alarm 2 25 Watchman The watchman function turns on the radar and transmits its for about 30 seconds at a predetermined interval to check for targets in a guard zone This feature is useful when you do not need the radar s function continu ously but want to be alerted to radar targets in an area When the watchman feature is on an inter nal timer turns on the radar every 5 10 or 20 minutes and the radar transmits for 30 sec onds to check for the existence of radar tar gets in a guard zone St by Tx St by N E E E 1min 5 100r imin 5 100r 20 min 20 min Watchman starts Figure 2 13How watchman works 1 Determine the guard zone usually 360 degrees with the guard alarm function 2 Press the MENU key to open the menu 3 Operate the trackball to select 7 WATCHMAN 4 Press the RANGE key to select a trans mission interval 5 Press the MENU key to actu
40. y cursor Operate the trackball to bisect the target with the cursor intersection The bearing to the target appears at the bottom of the display Measuring by EBL 1 Press the EBL key to display an EBL The EBL is the dotted line 2 5 2 Position the EBL so it bisects the target by operating the trackball 3 Press the EBL key again to fix the EBL to the position 4 Check the bearing readout to find the bearing of the target To erase the EBL press and hold down the EBL key for about three seconds MAG or GYRO BEARING MAG115 0 Target Cursor EBL EBL Cursor Bearing 40 0 R 41 5 R 5 1 7 4 0 NM Ned EBL1 bearing R Relative Bearing T True Bearing Heading sensor or gyrocompass connection required Figure 2 6 Measuring Bearing by the EBL and Cursor The bearing measured by the cursor or the EBL can be displayed in relative or true bear ings heading sensor or gyrocompass con nection required Relative bearings are relative to the bow of the vessel and true bearings are relative to the True North The indication MAG or GYRO and the head ing sensor or gyrocompass bearing your ship s bearing appear at the top of the screen Note that the bearing to the cursor always varies with trackball operation The EBL and its indication however are automatically fixed when the EBL key is pressed or 10 seconds elapses without trackball operation Tips on m
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