Raymarine a series Installation Instructions Manual

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Raymarine a series Installation Instructions Manual Manual pdf 113 page image

9.6 Sonar crosstalk interferenceThere are 2 types of potential sonar crosstalkinterference in a Raymarine sonar system:1. SideVision sonar crosstalk interference2. Multiple sonar crosstalk interferenceThe types of crosstalk interference that youmay experience in your system depend on thecombination and type of sonar equipment installed,and the way in which the equipment has beeninstalled.SideVision sonar crosstalkinterferenceMultiple sonar crosstalkinterferenceDue to the high sensitivityof SideVision transducers,you may experience someminor crosstalk interferencebetween the left and rightreceiving channels in areasof strong target returns.Examples of strong targetreturns include solid objectssuch as underwater bridgestructure. This interferenceshows up in the Fishfinderapplication as subtlereflections from the rightsonar image displayed inthe left sonar image, or viceversa.When using multiple sonarmodules and transducersoperating in overlappingfrequency ranges, you mayexperience some crosstalkinterference between theranges. This interference isdisplayed in the Fishfinderapplication as vertical “raindrops” throughout the watercolumn. These vertical “raindrops” indicate that 2 sonarmodules are operating inclose frequency proximity toone another.SideVision sonar crosstalk interferenceCrosstalk interference is expected behavior in a highsensitivity device such as a SideVision transducer,and is not indicative of a fault with your transducer orsonar module.Reducing multiple sonar crosstalkinterferenceCrosstalk interference in systems with multiple sonarmodules and transducers is the result of a numberof factors, including installation, operation, andenvironment.• Choose an equipment combination thatminimizes overlapping frequencies. Whereverpossible, choose to use sonar modules andtransducers that operate in different frequencyranges (“Channels”), for example CP100 andCP300 sonar modules and CPT-100 and B744Vtransducers. This will help to ensure that eachcomponent is operating in a distinct relativefrequency range – for example, a “high” frequencyrange for the CP100 and a “low” frequency rangefor the CP300.• Only use the sonar channels that you reallyneed. Although it is possible to run multiple sonarmodules simultaneously in a Raymarine system, itmay not always be necessary to do so. If you arein a scenario that requires only one sonar moduleto be active at a time, disable any other sonarmodules by changing the Fishfinder applicationpane to a single one which only displays the outputfrom one sonar module. Alternatively, disable theping for any unused sonar modules by selectingMENU > Channel > Ping > OFF in the Fishfinderapplication.• Identify the sonar module and transducer thatis causing the interference. To do this, disablethe ping or remove the power for one of the sonarmodules in your system. If the interference in theFishfinder application disappears immediately,you now know which device is causing theinterference. If the interference doesn’t disappear,repeat the exercise again with the other sonarmodule(s) in your system, one at a time. Once youknow which device is causing the interference,proceed with the following methods to reduce theinterference from the relevant device.• Adjust the Interference Rejection Filter. Thedefault setting for all Raymarine MFDs is “Auto”.Changing this setting to “High” might help toreduce interference (MENU > Setup > SounderSetup > Interference Rejection). Note that theInterference Rejection Filter setting is not availablefor all sonar modules.• Decrease the power output of the interferingtransducer. Adjusting the “Power Mode” inthe Sensitivity Settings in the MFD’s Fishfinderapplication can help to minimize the presenceof crosstalk interference (MENU > SensitivitySettings > Power Mode). Note that the PowerMode setting is not available for all transducers.• Ensure that you have a common RF groundpoint for all electrical equipment on yourvessel. On vessels without an RF ground system,ensure all product drain wires (where available)are connected directly to the negative batteryterminal. Ineffective RF grounding can causeelectrical interference which may in turn result insonar crosstalk interference.• Increase the physical distance between yoursonar modules. Electrical interference may beoccurring between a cable on one sonar module,and a cable on a different sonar module. Ensurethat your sonar modules are physically located asfar away from each other as possible.• Increase the physical distance between yoursonar transducers. Electrical and / or acousticinterference may be occurring between thedifferent transducers in your system. Ensure thatyour transducers are physically located as faraway from each other as possible.Note: Given the effort and potential difficultiesinvolved in relocating sonar equipment, it shouldonly be considered as a last resort when you judgethe interference to be a significant problem whichcannot be resolved using the methods describedabove.Troubleshooting 113