NorthStar Navigation NorthStar 491 Transducer depth, Changing the depth units, Depth Units option

Page 28

Transducer depth	This option specifies how far below the surface of the water
	the transducer is mounted. The number is added to all depths
	measured by the 491 so they will refer to depth from the
	surface, not from the transducer. This value should have been
	set correctly during installation and should not be changed.

Changing the depth units

Changing the temperature graph’s units and scale

This option only appears on the screen if a temperature sensor is connected.

Number of special waypoints

You can change the depth units to feet, meters, or fathoms:

1.Press the CURSOR PAD up or down to highlight the

DEPTH UNITS option.

2.Press EDIT.

3.Press the CURSOR PAD left or right to highlight the desired units. Press ACCEPT.

You can change the highest and lowest water temperatures that will be displayed on the temperature graph:

1.Press the CURSOR PAD up or down to highlight the line containing the temperature scale.

2.Press EDIT.

3.Press the CURSOR PAD left or right to highlight °C or °F, as desired, then press ACCEPT.

4.To change the endpoints of the scale, press EDIT DATA.

5.Enter the lower temperature limit using the KEYPAD.

6.Press the CURSOR PAD to the right to highlight the upper limit and enter its value on the KEYPAD.

7.Press ACCEPT.

In the 961/962, the echo sounder can be set to store waypoints automatically at the following location:

•where ﬁsh are detected by the ﬁsh alarm

•where the water temperature passes preset limits

•where ﬁsh or other echoes are marked by the user

These waypoints are automatically given names such as *FISH##*, where ## is a waypoint sequence number that increases to a preset limit. When this limit is reached, the

Page 24

491 Echo Sounder Operations Manual

Image 28

Contents Northstar Echo Sounder Contents Reviewing past echoes using SoundTrac Troubleshooting 491 OperationsPage 1Welcome Welcome to the Northstar Using this manualOrganization Conventions Technical support Service and repairHearing from you How echo sounding works 961/962 echo sounder system components Setting up Powering the 491 on and offUsing 491 with the 961/962 Using the 491 with the 957/958 Press the Port Setup Options key961/962 echo sounder menu structure 957/958 echo sounder menu structure 2Quick Start Using the Echo Sounder Displaying the echo sounder’s picture Illustrated Echo screenIllustrated Soundtrac screen At the Chart Overlay Selection window, press Using demo modeChart Overlay screen Depth and temperature Introducing the displayed informationEcho sounding Navigation Status tabsUsing automatic mode Cruising or ﬁshingChanging the frequency of echoes Manually overriding automatic mode50 kHz 200 kHz Echo screen with both frequencies displayed Zooming in and out Choosing a zoom modeChoosing the zoom scale Using bottom zoom Using bottom lock zoom Using bottom lock/ center zoom Setup functions Accessing the setup screenEntering numerical values Changing the temperature graph’s units and scale Transducer depthChanging the depth units Number of special waypointsSpeed and temperature sensor setup 961/962 sensor setup screen957958/ sensor setup screen 3Adjusting the Echo Sounder Picture Adjusting the gain strong echoes Picture menuAdjusting the clutter weak echoes Gain windowAdjusting the signal level weak echoes Clutter windowSuppressing interference the noise limiter Selecting the color bar hue and white level Understanding the color barSetting the white level Hue and white level windowEcho Sounder Operations Manual 4Understanding Depth Settings Viewing the seabed depth Changing the depth settingsViewing the depth marker Setting the picture’s shift starting depth Shift windowSetting the picture’s range Range window Echo Sounder Operations Manual 5Other Functions Using the More key Using the More key Changing the advance speedDisplaying the A-scope Scope on single-frequency echo screenUsing the A-scope with dual frequencies Setting the Echo screen dataScope on dual-frequency echo screen Bottom depth box Temperature box Echo screen data selectionsTemperature graph Introducing snapshotsSpeed through the water Taking and storing a snapshotArchiving and restoring a snapshot with a ﬂoppy disk Snapshot screen 961/962 onlyArchiving and restoring snapshots with a Zip disk Archiving snapshots screen 961/962 onlySetting up the video image overlay Echo Sounder Operations Manual 6Reviewing past echoes using SoundTrac Viewing past echoes using SoundTrac SoundTrac screenMarking ﬁsh as waypoints Navigating to a past echo positionGoing directly to a past echo position Selected Cursor Position window appears7Setting the Alarms Understanding the alarms Setting the ﬁsh alarmSetting the upper and lower marker depths Fish alarm windowSetting the bottom alarm Setting inside or outside ﬁsh markersAlarm Turning the ﬁsh alarm on and offSetting the bottom level Bottom alarm windowTurning the bottom alarm on and off Setting the temperature alarmTemperature alarm window Turning the temperature alarm on and off Upper limit window is highlighted in blackWhen the temperature alarm sounds, an alert message is 8Troubleshooting 491 Operations Troubleshooting the echo sounder Checking the transducerTroubleshooting the echo sounder No echoes displayed when Star key is pressedChecking the transducer OFFManufacturer Model Power Northstar P/N Maintaining a transducerA491 Features and Speciﬁcations Performance characteristicsPhysical characteristics Environmental characteristicsScreen notations InterfacingManual controls ON/OFFEcho Sounder Operations Manual Glossary Echo Sounder Operations Manual