NorthStar 8000i System Operation Manual page 10

15 The sounder
15.1 How the sounder works .....................................................................................................................101
16 Use the sounder
16.1 Display the sounder screen...............................................................................................................102
16.2 What does the sounder screen show? ..........................................................................................102
16.3 What does the sounder status bar show? ....................................................................................103
16.4 Change the scroll speed.....................................................................................................................103
16.5 Change the palette ..............................................................................................................................104
16.6 Show/hide the depth value ..............................................................................................................104
16.7 Show/hide the depth line..................................................................................................................105
16.8 Move the depth line ............................................................................................................................105
16.9 Change the sounder operating mode...........................................................................................105
16.10 When to use 50 kHz, 200 kHz, or mixed frequency...................................................................106
16.11 Select 50 kHz, 200 kHz or mixed frequency screen...................................................................107
16.12 Select a split 50/200 kHz screen ......................................................................................................107
16.13 Select a split zoom screen .................................................................................................................108
16.14 What is zoom range and zoom range shift?................................................................................108
16.15 Change the zoom range shift...........................................................................................................108
16.16 Select a split bottom lock screen ....................................................................................................109
16.17 Change the ratio of a split screen ...................................................................................................109
16.18 What is the A-Scope? ..........................................................................................................................110
16.19 Show/hide the A-Scope .....................................................................................................................111
16.20 Change the ratio of the A-Scope.....................................................................................................111
17 How to interpret the sounder screens
17.1 What are fish arches? ..........................................................................................................................112
17.2 Problems with fish arches?................................................................................................................112
17.3 How to recognize different types of fish ......................................................................................113
17.4 How to recognize and avoid shadows ..........................................................................................113
17.5 How to recognize the type of bottom...........................................................................................113
17.6 How the water depth and scroll speed affect the history ......................................................113
17.7 Factors that affect the echo strength ............................................................................................114
18 Change the sounder range and gain
18.1 What is gain?..........................................................................................................................................115
18.2 Change the gain setting.....................................................................................................................115
18.3 What is the gain threshold? ..............................................................................................................116
18.4 Change the gain threshold ...............................................................................................................116
18.5 What is auto range and range shift? ..............................................................................................117
18.6 Turn the auto range on or off...........................................................................................................117
18.7 Change the range shift.......................................................................................................................118
18.8 Change the range.................................................................................................................................118
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