Humminbird 161 manual Finding the Cause of Noise, Isolation, Boat’s engine, Cavitation from

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Finding the Cause of Noise

Electrical noise usually affects the display with many black dots at high speeds, and high sensitivity readings. One or more of the following sources can cause noise or interference:

Possible Source of Noise	Isolation
Other electronic devices	Turn off any nearby electronic devices to see if the
	problem goes away, then turn them on one at a
	time to see if the noise re-appears.
The boat’s engine	To determine whether the boat’s engine is the
	source of the noise, increase the RPMs while the
	boat is in neutral and stationary to see if the noise
	increases proportionately; if noise appears when
	you rev the engine, the problem could be the
	spark plugs, alternator, or tachometer wiring.
	Replace the spark plugs with resistor plugs, install
	an alternator filter, or route the control head
	power and transducer cables away from the
	engine wiring.
Cavitation from the	Turbulence created by the propeller can cause
boat’s propeller	noise; make sure the transducer is mounted at
	least 15” (38 cm) from the propeller, and that the
	water flows smoothly over the face of the
	transducer at all times.

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Contents GPS Chartplotter Operations Manual Thank You Table of Contents Iii Key FunctionsSonar Menu Tab Chart Menu Tab Specifications Glossary Contact Humminbird 103 How Sonar Works Peak to Peak measures power output at the highest points How GPS and Cartography Work Single Beam SonarPage Bait Ball Hard Bottom Rocky Bottom What’s On the DisplayAdjacent to your boat, including the following items Structure where fish may be hidingViews Zoom View Chart View Big Digits ViewSonar views Sonar ViewSonar View Real Time Sonar RTS Window Understanding Sonar HistoryBottom Presentation Freeze FramePage Sonar Zoom View Sonar Zoom ViewCircular Flasher View Big Digits ViewBird’s Eye View Bird’s Eye ViewChart View without Active Cursor Chart ViewView Orientation Combo ViewViewing Cartography Chart View with Cursor PresentWaypoints, Routes and Tracks Introduction to NavigationSave, Edit, or Delete a Waypoint Navigate to a Waypoint or Position Add a Waypoint Target or Trolling Grid Navigation X-PressTMmenuSave, Edit or Delete a Route Edit, Delete or Hide Saved Tracks Save or Clear a Current TrackKey Functions POWER/LIGHT KeyView Key Info KeyWAY Cursor Control Key Menu KeyGoto Key Mark KeyZoom +/- Key Exit KeyMenu System Powering Up the UnitSonar Tab Normal Mode Advanced Mode Start-Up Options Menu Normal OperationNormal Simulator System Status System Status SimulatorSelf Test Accessory TestGPS Diagnostic View GPS Diagnostic ViewSonar views only Sonar X-PressTMMenuTo adjust the Sensitivity SensitivityHighlight Sensitivity on the Sonar X-PressTMmenu Upper Range To adjust the Upper RangeTo adjust the Lower Range Lower RangeHighlight Lower Range on the Sonar X-PressTMmenu To adjust the Chart Speed Chart SpeedTo adjust the Bottom View Bottom ViewBottom Range To adjust the Bottom RangeBottom Lock To turn on Bottom LockTo Cancel Navigation Cancel NavigationHighlight Cancel Navigation on the Sonar X-PressTMmenu Only when NavigatingNavigation views only Navigation X-PressTMMenuTo view the Waypoint Name Submenu Waypoint NameHighlight WaypointName on the Navigation X-PressTMmenu Waypoint Submenu contains the following menu choicesCursor to Waypoint Chart or Combo view onlySave Current Track To move cursor to a saved waypointClear Current Track Save Current RouteSkip Next Waypoint Remove Target Highlight Cancel Navigation on the Navigation X-PressTMmenuTo Remove a Target Only if a Target is ActiveSonar Window Remove GridTo Remove a Grid To Set the Size of the Sonar Window in the Combo ViewMost recently-created waypoint Press the Menu key twice to access the Main Menu Sonar Menu TabSonar tab To turn Fish ID+ on or off Fish ID+TMTo change the RTS Window setting To change the Fish ID Sensitivity settingFish ID Sensitivity Highlight Fish ID Sensitivity on the Sonar main menuTo change the Depth Lines setting To change the Zoom Width SettingZoom Width Depth LinesSurface Clutter To change the Surface Clutter settingTo change the Max Depth setting To change the Noise Filter settingNoise Filter Max DepthWater Type To change the Water Type settingNavigation tab Navigation Menu TabCurrent Track allows you to view the Current Track submenu Current TrackTo view the Current Track Submenu Highlight Current Track on the Navigation main menuSaved Tracks allows you to view the Saved Tracks submenu Saved TracksTo view the Saved Tracks Submenu Highlight Saved Tracks on the Navigation main menuTo view the Waypoints Submenu WaypointsHighlight Waypoints on the Navigation main menu Waypoints Submenu contains the following menu choicesTo view the Routes Submenu RoutesHighlight Routes on the Navigation main menu Routes Submenu contains the following menu choicesChart Orientation North ReferenceGrid Rotation To change the Track Minimum Distance setting To change the Trackpoint Interval settingTrackpoint Interval Track Min DistanceMap Datum Course Projection LineDelete All Nav Data Chart Menu Tab Chart Detail Level To change the Chart Detail Level settingHighlight Chart Detail Level on the Chart main menu To change the Lat/Lon Grid setting To change the Map Borders settingMap Borders Lat/Lon GridTo set the Simulation Position Set Simulation PositionSet Map Offset To change the Map Offset settingClear Map Offset To Clear Map OffsetAlarms Menu Tab Fish ID Alarm Depth AlarmTo change the Depth Alarm setting To change the Fish ID Alarm settingTemp Alarm Low Battery AlarmTo change the Low Battery Alarm setting To change the Temp Alarm settingArrival Alarm Off Course AlarmTo change the Off Course Alarm setting To change the Arrival Alarm settingAlarm Tone Drift AlarmTo change the Drift Alarm setting To change the Alarm Tone settingSetup Menu Tab Units Depth Units TempUnits Distance User Mode Units SpeedLanguage Restore Defaults Triplog ResetTo Reset Triplog To Restore DefaultsAdvanced, Sonar view only Select ReadoutsTo change the Depth Offset setting Depth OffsetTo Select Readouts To change the Speed Calibration setting To change the Temp Offset settingTemp Offset Speed CalibrationLocal Time Zone To change the Daylight Saving Time settingDaylight Saving Time To change the Local Time ZonePosition Format To change the Position Format settingTime Format To change the Time FormatDate Format Nmea OutputTo change the Date Format Sonar To turn Nmea Output on or offTo turn Sonar on or off Combo View Views Menu Tab To Change the View Status of Any View Highlight the View main menu tabSeriesTM Defaults to Simulator with a Transducer Attached TroubleshootingDisplay Problems Problem Possible CauseOr faulty Isolation Finding the Cause of NoiseBoat’s engine Cavitation fromSpecifications Sonar Terms GlossaryPage Page Page Page Receiver See Transmitter Page Page Page GPS & Navigation Terms Page Page 100 101 102 103 104 105 Contact Humminbird