NorthStar Navigation NorthStar 491 instruction

The alarm	When the temperature alarm sounds, an alert message is
	displayed. This message clears automatically after 20 seconds
	and the alarm is reset.

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491 Echo Sounder Operations Manual

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NorthStar Navigation NorthStar 491 manual When the temperature alarm sounds, an alert message is

Contents

Northstar Echo Sounder Contents Reviewing past echoes using SoundTrac Troubleshooting 491 OperationsPage 1Welcome Using this manual Welcome to the NorthstarOrganization Conventions Service and repair Technical supportHearing from you How echo sounding works 961/962 echo sounder system components Powering the 491 on and off Setting upUsing 491 with the 961/962 Using the 491 with the 957/958 Press the Port Setup Options key 961/962 echo sounder menu structure 957/958 echo sounder menu structure 2Quick Start Using the Echo Sounder Displaying the echo sounder’s picture Illustrated Echo screen Illustrated Soundtrac screen Using demo mode At the Chart Overlay Selection window, pressChart Overlay screen Echo sounding Depth and temperatureIntroducing the displayed information Navigation Status tabs Using automatic mode Cruising or ﬁshing Manually overriding automatic mode Changing the frequency of echoes50 kHz 200 kHz Echo screen with both frequencies displayed Choosing a zoom mode Zooming in and outChoosing the zoom scale Using bottom zoom Using bottom lock zoom Using bottom lock/ center zoom Setup functions Accessing the setup screen Entering numerical values Changing the depth units Changing the temperature graph’s units and scaleTransducer depth Number of special waypoints Speed and temperature sensor setup 961/962 sensor setup screen 957958/ sensor setup screen 3Adjusting the Echo Sounder Picture Adjusting the gain strong echoes Picture menu Adjusting the clutter weak echoes Gain window Adjusting the signal level weak echoes Clutter window Suppressing interference the noise limiter Selecting the color bar hue and white level Understanding the color bar Setting the white level Hue and white level window Echo Sounder Operations Manual 4Understanding Depth Settings Changing the depth settings Viewing the seabed depthViewing the depth marker Setting the picture’s shift starting depth Shift window Setting the picture’s range Range window Echo Sounder Operations Manual 5Other Functions Using the More key Using the More key Changing the advance speed Displaying the A-scope Scope on single-frequency echo screen Setting the Echo screen data Using the A-scope with dual frequenciesScope on dual-frequency echo screen Bottom depth box Temperature box Echo screen data selections Speed through the water Temperature graphIntroducing snapshots Taking and storing a snapshot Archiving and restoring a snapshot with a ﬂoppy disk Snapshot screen 961/962 only Archiving and restoring snapshots with a Zip disk Archiving snapshots screen 961/962 only Setting up the video image overlay Echo Sounder Operations Manual 6Reviewing past echoes using SoundTrac Viewing past echoes using SoundTrac SoundTrac screen Marking ﬁsh as waypoints Navigating to a past echo position Going directly to a past echo position Selected Cursor Position window appears 7Setting the Alarms Understanding the alarms Setting the ﬁsh alarm Setting the upper and lower marker depths Fish alarm window Alarm Setting the bottom alarmSetting inside or outside ﬁsh markers Turning the ﬁsh alarm on and off Setting the bottom level Bottom alarm window Setting the temperature alarm Turning the bottom alarm on and offTemperature alarm window Turning the temperature alarm on and off Upper limit window is highlighted in black When the temperature alarm sounds, an alert message is 8Troubleshooting 491 Operations Troubleshooting the echo sounder Checking the transducer Troubleshooting the echo sounder No echoes displayed when Star key is pressed Checking the transducer OFF Manufacturer Model Power Northstar P/N Maintaining a transducer A491 Features and Speciﬁcations Performance characteristics Screen notations Physical characteristicsEnvironmental characteristics Interfacing Manual controls ON/OFF Echo Sounder Operations Manual Glossary Echo Sounder Operations Manual