Lowrance electronic LCX-15CI, LCX-15CT manual Noise

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NOISE

A major cause of sonar problems is electrical noise. This usually appears on the sonar’s display as random patterns of dots or lines. In severe cases, it can completely cover the screen with black dots, or cause the unit oper- ate erratically, or not at all.

To eliminate or minimize the effects of electrical noise, first try to deter- mine the cause. With the boat at rest in the water, the first thing you should do is turn all electrical equipment on the boat off. Make certain the engine is off, also. Turn the sonar unit on, then turn off ASP (Advanced Signal Processing). There should be a steady bottom signal on the display. Now turn on each piece of electrical equipment on the boat and view the effect on the sonar’s display. For example, turn on the bilge pump and view the sonar display for noise. If no noise is present, turn the pump off, then turn on the VHF radio and transmit. Keep doing this until all electrical equip- ment has been turned on, their effect on the sonar display noted, then turned off.

If you find noise interference from an electrical instrument, trolling motor, pump, or radio, try to isolate the problem. You can usually reroute the sonar unit’s power cable and transducer cable away from the wiring that is causing the interference. VHF radio antenna cables radiate noise when transmitting, so be certain to keep the sonar’s wires away from it. You may need to route the sonar unit’s power cable directly to the battery to isolate it from other wiring on the boat.

If no noise displays on the sonar unit from electrical equipment, then make certain everything except the sonar unit is turned off, then start the en- gine. Increase the RPM with the gearshift in neutral. If noise appears on the display, the problem could be one of three things; spark plugs, alter- nator, or tachometer wiring. Try using resistor spark plugs, alternator fil- ters, or routing the sonar unit’s power cable away from engine wiring. Again, routing the power cable directly to the battery helps eliminate noise problems. Make certain to use the in-line fuse supplied with the unit when wiring the power cable to the battery.

When no noise appears on the sonar unit after all of the above tests, then the noise source is probably cavitation. Many novices or persons with limited experience make hasty sonar installations which function perfectly in shallow water, or when the boat is at rest. In nearly all cases, the cause of the malfunction will be the location and/or angle of the transducer. The face of the transducer must be placed in a location that has a smooth flow of water at all boat speeds. Read the transducer instructions for the best mounting position.

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Contents LCX-15CI LCX-15CT Never use this product while operating a vehicle Specifications Table of Contents Model AccessoriesIntroduction Transducers ModelInstallation BracketPower Connections NMEA/DGPS Wiring NMEA/DGPSAccessory Connections Speed/Temperature ConnectionsTemperature and Speed/Temperature Installation Examples Sonar ConnectorMMC Keyboard Full Sonar Chart PagesSplit Zoom Sonar Chart Menus Sonar Options SensitivityAutomatic Sensitivity Colorline Range AutomaticRange Manual Range Upper and Lower LimitsZoom Stop ChartChart Speed Depth CursorChart Data Sonar FeaturesTransducer Frequency Surface ClarityNoise Rejection Sonar Features Fish Symbols Fish DepthsLOG Sonar Chart Data Alarms AudioDepth Alarms Zone AlarmFish Alarm Sonar SetupTransducer Type Reset Water Distance Keel OffsetCalibrate Speed System Setup Sonar SimulatorUnits of Measure Set Local Time Communications PortsConfigure Dgps Configure NmeaReset Options Hide GPS features Popup HelpSoftware Information GPS Operation Introduction to GPSNever use this GPS receiver while operating a vehicle Finding Your Position Auto SearchManual Initialization Position Aquisition Require Dgps GPS Operation PagesStatus Customizing the Status Screen NavigationCustomizing the Navigation Screen MapPage Cursor Cursor Distance Map OrientationNORTH-UP Auto Zoom Range Rings/Grid LinesMap Data Map Categories Drawn IconsPlot Trail Edit Trail Navigate a TrailPage Trail Options New TrailDelete All Trails Waypoints Saving the Cursor Position as a WaypointSaving a New Position Average Position Waypoint InformationWaypoint Navigation MAN Overboard Cancel Navigation RoutesCreate a Route Page Follow a Route GPS SimulatorGPS Setup Coordinate SystemMap Fix Datum Position Pinning Important Alarm Notes Timers/Alarm Clock Trip CalculatorUnit won’t turn on Unit freezes, locks up, or operates erraticallyNo fish arches when the Fish ID feature is off Noise Lowrance ELECTRONICS, INC Full ONE-YEAR Warranty Datums Datums Datums Lowrance Databases License Agreement Databases Limited Warranty Page Transferring GPS Data to/from a MMC How to Obtain Service How to Obtain Service U.S.A. Only
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