NorthStar Navigation EXPLORER 657 operation manual Interpreting the display, Strength of echoes

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The scroll speed depends upon the water depth and scroll speed setting. See sections 17-3 and section 8-2, for more information.

The appearance of echoes displayed are affected by:

the 657 settings (see sections 17-3, 8-5 and 8-6)

echoes (different fish types, different bottom types, wrecks and seaweed; see section 8-2)

noise (water clarity and bubbles; see section 8-2).

Cruising, Fishing and Manual Modes

The 657 has three sonar operating modes:

Cruising mode: Use this when on the move. The 657 automatically adjusts its settings to compensate for water clarity and to display the bottom.

Fishing mode: Use this when fishing. The 657 automatically adjusts its settings to compensate for water clarity and to best display fish, the bottom and other details.

Manual mode: Use this to fine-tune the 657 settings by hand. Best results are often achieved in manual mode, but practice and experience are required to obtain the optimum settings for different conditions.

For more information about modes, see sections 8-5 and 8-6.

! WARNING

Use the automatic Cruising or Fishing modes when learning to use the 657 or when travelling at speed.

8-2 Interpreting the display

The sonar displays do not show a fixed distance

Strength of echoes

travelled by the boat; rather, they display a

The colours indicate differences in the strength of

history, showing what has passed below the boat

the echo. The strength varies with several factors,

during a certain period of time.

such as the:

 

The history of the sonar signal displayed depends the depth of the water and the scroll speed setting.

In shallow water, the echoes have a short distance to travel between the bottom and the boat. In deep water, the history moves across the display more slowly because the echoes take longer to travel between the bottom and the boat. For example, when the scroll speed is set to Fast, at depths over 1000 ft (300 m) it takes about 2 minutes for the data to move across the display, whereas at 20 ft (6 m) it takes only about 25 seconds.

The scroll speed can be set by the user to display either a longer history with less fish information or a shorter history with more fish details (see section 17-3).

If the boat is anchored, the echoes all come from the same area of bottom. This produces a flat bottom trace on the display.

The screen shot shows a typical sonar display with the Fish symbols turned Off.

Size of the fish, school of fish or other object.

Depth of the fish or object.

Location of the fish or object. (The area covered by the ultrasonic pulse is a rough cone shape and the echoes are strongest in the middle.)

Clarity of water. Particles or air in the water reduce the strength of the echo.

Composition or density of the object or bottom.

Note: Planing hulls at speed produce air bubbles and turbulent water that bombard the transducer. The resulting ultrasonic noise may be picked up by the transducer and obscure the real echoes.

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Northstar Explorer 657 Installation and Operation Manual

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Contents Explorer Possible injury or death Could result in death or serious injuryCould result in minor or moderate injury DamagePage Contents Tides window User card window 15 AIS Installation Northstar petrol/gasoline sensors Installation Other Nmea instrumentsIntroduction Cleaning and maintenance OverviewPlug-in cards 657 can use two kinds of plug-in cardChanging the plug-in card Removing the display unitTurn the display unit off see -2 and put the dust cover on Replacing the display unitUsing the keys Using the menusBasic Operation Overview of the keysTurning on and off / auto power Turning on manually Turning off manuallyBacklight and night mode Night modeTo cancel MOB or set another MOB Man overboard MOB657 has user settable alarms see section AlarmsSimulate mode Main windows Page Multi window displays Favorite displays Selecting a favorite displayAdding a favorite display to the list Deleting a favorite display from the listSetting the data header for a display Data headerCompass Displays can show data at the top, called the data headerNavigation Chart Going to a waypoint or to a point on the chartIntroduction to navigating Navigating to a pointStarting a route from the chart window Cancelling a routePreparing Starting a route from the routes windowChart window To go to the Chart window, press then select ChartTypical chart window shows Land Sea Cursor see section Typical waypoint see sectionChart modes Chart scaleChart symbols and information Latitude and longitudeFinding a chart symbol Perspective viewDistance and bearing calculator Projected courseNavigation Highway window Tracks and trackingTime intervals Interval Track Track 2, 3, 4 or Interval Track Track 2, 3, 4 orNavigation Waypoints Waypoints windowDisplaying a waypoint on the chart Managing waypointsCreating a new waypoint Moving a waypointNavigation Routes Deleting all waypointsChanging a waypoint’s data Sort WaypointsCreating a new route from the chart window Routes windowManaging routes Creating a new routeDisplaying a route on the chart Editing a route from the chartEditing a route Creating a new route from the routes windowSatellites Using Sonar fishfinding IntroductionSatellite window Satellite window showsInterpreting the display Strength of echoesBottom types Frequency and cone widthWater DepthWhen to use 50 kHz When to use 200 kHzShadows Example of shadowsWhen to use Mixed When to use 50/200 kHzKHz display 200/50 Khz display Mixed display Minute ago Seconds ago NowFish arches Fish detection and display Where to find fishFish symbols Range 657 has two range modesAuto Zoom range and offsetChanging mode Gain and thresholdGain window This display is called the gain windowSonar fishfinding Displays Sonar history display no splitExtended history mode Sonar Zoom and Full Screen Zoom displaysScreen. Press to return to the most recent echo History position barSonar Bottom display Sonar 50/200 displaySetting gain and threshold Sonar A-Scope displayFish recognition Bottom typeGauges window Data windowSelecting a Gauges layout Changing a gauge layoutFuel functions and display What the fuel computer doesFuel window Fuel window showsWhen you add or remove fuel Boat speed sensors Low fuel alarmWhen you remove fuel Speed Log Economy Water speed and ground speedSpeed Log Economy Range Fuel consumption curves Making a curveStart running the boat in a straight line Press twice, then select FuelUsing a curve Renaming a curveDeleting a curve Selecting a curveTo the reading of the fuel dispenser’s gauge Then press Setup enginesCalibration Tides window shows data for the chosen date Choosing the date of the tide chartTides window Saving data to the user card User card windowUser card window has 15 AIS Deleting a file from the user cardSorting the file names Rereading the file informationViewing AIS Vessels Safety msgs rx AIS WindowsVessels Displaying Full AIS Details16 DSC/Buddy track windows Displays Distress PollUsing the displays Displaying a boat on the chart Boat positionsCreating a waypoint Deleting a boatSetting up Time see Favorites see 17-14 Simulate see Setup option menusSmartCraft Setup System Auto power offFactory reset LanguageSetup Chart Setting map datumRotation PaletteNmea datum offset Map shiftApplying a map shift Map shiftLat/lon grid Setup Sonar Pulse powerFrequency Digit sizeSetup GPS Setup FuelGPS Source Dgps SourceSetup engines Setup tanksSource Num enginesSetup Track DistanceTime RecordSetup AIS Show Dangerous Only Setup LogsReset total dist Reset engine hoursSetup Alarms Symbol AlarmArrival radius Anchor alarm Alarm sounds when it is onSetup Units TemperatureSetup Comms FuelSetup Calibrate Temperature filterSpeed Speed filterSetup Time Setup FavoritesKeel Offset Speed rangeInstallation Setup SimulateSimulate ModeInstallation What comes with Installation Options and AccessoriesOptional sensors and instruments GPS or Dgps antenna For GPS navigation see sectionPower/data cable Pin Wire FunctionConnections Display unit 18-3 Black Yellow BlueInstallation The display unit Flush MountingBracket Mounting There are two mounting arrangementsInstallation Power/data cable Basic powerBlack Power/data cable Red Yellow Fuse 2A Auto powerDgps Source Installation GPS antenna Selecting an antennaInstalling an antenna Blue Sonar cable Either Installation Sonar transducerInstallation Northstar petrol/gasoline sensors NavBus Installation SmartCraftInstallation Other NavBus instruments Installation Northstar VHF radio Installation Other Nmea instrumentsInstallation Setup and test Enter setup data to set up the 657 to yourIf the display unit is bracket mounted, adjust Tilt and rotation for best viewing and handAppendix a Specifications South American List of datumsAdindan Afgooye Appendix B Troubleshooting General problemsGPS navigation problems Fuel consumption problemsSonar fishfinding problems Twin engine installation shows only one flow rateErratic Fuel Flow readings There is no reading for fuel economyThere is a double bottom trace displayed Bottom is not displayedBottom is displayed too far up the screen Appendix C Glossary and navigation data GlossaryNavigation data TBMFT!COUNBSJOFDPN