Furuno 841 User Manual Page 1

MARINE RADARMODELMODEL 821/841

viii5ANAVVideo SounderGyroGyro ConverterAD-100*Equivalent to NMEA0183OptionIEC 1162*IEC 1162*(In/Out)(In)Fluxgate HeadingSensor C-2000Antenna Unit(MO

11. PRINCIPLE OFOPERATION1.1 What is Radar?The term "RADAR" is an acronym mean-ing RAdio Detection And Ranging. Al-though the basic principl

2ABCDOwn ship(radar)DABCHeading markerTargetsOwn shipin centerRange and bearingof a target, relativeto own ship, arereadable on the PPI.(A) Bird&apos

32. OPERATION2.1 Control DescriptionCursor padShift cursor, VRMand EBL; selectitems and optionson menu.Selects display mode;erases heading errorindica

42.2 Display Indications and Markers 0.5RangeRange ring intervalEcho trail, AUTO tuningEcho trail elapsed time,echo trail time, tuning in

52.4 TransmittingAfter 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 n

62.8 Adjusting GAIN, STC, A/CRAIN and FTCGeneral procedureThe [ECHO] key enables adjustment of thegain, STC, A/C RAIN and FTC.1) Press the [ECHO] key

7How 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 i

8 1.5NM 0.5VRMrangeVRMTarget VRM EBL + CURSOR 0.675NM 220.9°R 0.675NM 308.7°RFigure 2-8 Measuri

C 9-52, Ashihara-cho, Nishinomiya, Japan Telephone: 0798-65-2111 Telefax: 0798-65-4200 Your Local Agent/Dealer All rights res

9To erase the EBL, press and hold down the[EBL] key for about three seconds. 1.5NM 0.5EBLTargetEBLbearing VRM EBL

10Table 1-1 Menu descriptionMenuFunction1. Selects control panel backlighting; four is maximum backlighting.2. Selects brilliance for echo trails

112.13 Selecting the DisplayModeThe display mode may be selected with the[DISP MODE] key. Four modes are avail-able (with navigation input): Normal, N

122.14 The Window DisplayThe window display appears at the bottomright (or left) 1/4 of the display. Two typesof window displays are available: zoom

13WPT-UP (waypoint-up)An azimuth stabilized display in which theline connecting the center with the top ofthe display indicates the bearing to the “TO

14reverse video. You can silence the alarm bypressing the [GUARD] key. When this isdone, G (ACKN) replaces G (IN) (or G(OUT)).Press the [GUARD] key a

15corner on the display when the interferencerejection circuit is turned on.2.18 Suppressing NoiseInterferenceNoise interference appears on the screen

162.21 Echo TrailsYou can show the trails of targets in after-glow. This function is useful for alerting youto possible collision situations.Starting

17 1.5NM 0.5HDG 326.8° 66° 04. 00N166° 04. 00EVRM EBL + CURSOR0.675NM 240.1°R 0.646 NM 308.7

185) 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 fu

DANGERSafety ArrangementsAll known steps are taken in the design of this radar to ensure that electromagnetic radiofrequency energy radiated by the eq

19Press 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 Heading

202.30 Outputting CursorPosition to NavigatorCursor position (NMEA0183 data sentenceTLL) can be output to the navigator con-nected to this radar by p

21Radar horizonRadar is essentially a “line-of-sight” phe-nomenon. That means you have just aboutthe same range to horizon with a radar asyou do with

22On the other hand, hulls made from woodor fiberglass return much weaker echoes.Vertical surfaces, such as a cliff, are goodtargets provided they fa

23Indirect echoesIndirect echoes may be returned from eithera passing ship or returned from a reflectingsurface on your own ship, for example, astack.

24Blind and shadow sectorsFunnels, stacks, masts, or derricks in the pathof antenna may reduce the intensity of theradar beam. If the angle subtended

254. MAINTENANCE &TROUBLESHOOTINGThis chapter tells you how to keep your ra-dar in good working order. Before review-ing this chapter please read

264.2 Preventative MaintenanceRegular maintenance is important for goodperformance. Always keep the equipment asfree as possible from dirt, dust, and

274.4 TroubleshootingTable 4-2 contains simple troubleshootingprocedures which you can follow to try torestore normal operation. If you cannot re-stor

284.5 Self TestThe self test facility checks the keyboard,ROM and RAM for proper operation. Youmay run the test as follows.1) Press the [MENU] key.2)

iTABLE OF CONTENTSFOREWORD ...iiSPECIFICATIONS ...iiiEQUIPMENT LIST ...

295. INSTALLATIONThis chapter covers installation. Installationmainly consists of the following:• siting and mounting the display unit andthe antenna

30Mounting platform3) Prepare a platform of 5 to 10mm inthickness for the antenna unit. (For sail-boats, an optional mounting bracketwhich can be fix

315) Make sure the vent tube is in the correctposition, and then fasten the radome baseto the mounting platform with four eachof M10 x 20 hex bolts, f

325) Connect three plugs to the antenna unit:P801 (9 way), P813 (2 way), and P810(10 way).TP804J813J810J801Figure 5-5 Antenna unit (MODEL 821), insi

33Mounting procedure for MODEL 841Removing packing materials1) Open the radome cover carefully. Re-move mounting hardware at the bottomof the radome b

345) Make sure the vent tube is in the correctposition, and then fasten the radome baseto the mounting platform with four eachof M10 x 20 hex bolts,

358) Put the radome on the radome base as-sembly. The arrow should face towardthe bow.Figure 5-11 How to position theradome cover (MODEL 841)9) Tighte

365.2 Display Unit InstallationMounting considerationsWhen selecting a mounting location for thedisplay unit keep in mind the followingpoints.• The d

37*140 (5.51")10(0.39")238(9.37")18(0.71")18(0.71")*80 (3.15")*80 (3.15")100 (3.94")20(0.79")274(10.79&q

38ConnectionsConnect the signal and power cables, theground wire and optional equipment asshown in Figure 5-14.Figure 5-14 Display unit, rear viewRPH

iiFOREWORDCongratulations on your choice of theFURUNO MODEL 821/MODEL 841 Ma-rine Radar. We are confident you will seewhy the FURUNO name has become

39SPU-9180DISPLAYUNITJ61VIDEOSOUNDERCable suppliedwith radar(connector assy.03-1796(5))Cable suppliedwith video sounderSolder andtape.Figure 5-15 How

405. Add jumper wire between J55 pin#3(RXD-H) and J61 pin #1(TXD-H).6. Add a jumper wire between J55 pin#4(RXD-C) and J61 pin #5(SHIELD).JP3 JP4CR14R

41❒ Are all connectors at the rear of thedisplay unit fastened securely?CAUTIONIf it is necessary to open the display unit, be surethe rear cover is f

423) Press the cursor pad to select Installa-tion Setup 1 and press the [ENT] key.● INSTALLATION SETUP 1 ●Select item and optionby ▲▼ keys.1. Key Bee

436) As a final test, move the boat towards asmall buoy and confirm that the buoyshows up dead ahead on the radar whenit is visually dead ahead.5.8 Sw

445.10 Signal cable connection1. Connect the signal cable to DJ-1 on therear panel of the display unit.Rubber coverDJ Connector Boot-bandCableDisplay

iiiSPECIFICATIONS–MODEL 821Antenna Unit1. RadiatorPrinted array2. Radiator length40 cm3. Horizontal beamwidth5.7°4. Vertical beamwidth30˚5. SidelobeLe

ivWith navigation input (option): Course(CRS), Latitude and longitude, Speed(SPD), Range and bearing to waypoint(WP), Cross Track Error (XTE), Datean

v9. Receiver front endMIC (Michoeave IC)10. Bandwidth7 MHz11. DuplexerCirculator with diode limiterDisplay Unit1. Indication systemPPI raster scan2. D

vi17. Compass safe distanceInterface NMEA (MODEL 821/841)InputOwn ship’s position : RMA>RMC>GLL(GLL is available Ver.5 and after.)Speed : RMA&