Humminbird 4089701 Power On, How Sonar Works, What’s on the Sonar Display, What’s on the Down Imaging™ Display, Views, What's on the 500 Series™ Control Head, Key Functions

Table of Contents
Power On	1
How Sonar Works	2
Single Beam Sonar (550, 560) ....................................................................................	4
DualBeam PLUS™ Sonar (561, 570) ..........................................................................	5
Down Imaging™ Sonar (561 DI, 570 DI, and 571 HD DI) ................................................	6
What’s on the Sonar Display	7
Understanding the Sonar Display ............................................................................	9
Real Time Sonar (RTS™) Window ............................................................................	9
Sonar Returns and Bottom View ...........................................................................	10
SwitchFire™ ..........................................................................................................	12
Freeze Frame and Active Cursor ...........................................................................	12
Instant Image Update ............................................................................................	12
What’s on the Down Imaging™ Display
(Down Imaging™ models only [561 DI, 570 DI, and 571 HD DI])	13
Understanding the Down Imaging™ Display ........................................................	15
Interpreting the Display ..........................................................................................	15
Down Imaging™ Sensitivity .................................................................................	16
Freeze Frame and Active Cursor ...........................................................................	16
Views	17
Sonar View ............................................................................................................	19
Sonar Zoom View ..................................................................................................	20
Split Sonar View (DualBeam PLUS™ and
Down Imaging™ models only [561, 570, 561 DI, 570 DI, and 571 HD DI])........................	21
Big Digits View ......................................................................................................	22
Down Imaging™ View (Down Imaging™ models only [561 DI, 570 DI, and 571 HD DI]) ..	23
Down Imaging™/Sonar Combo View (Down Imaging™ models only
[561 DI, 570 DI, and 571 HD DI]) ................................................................................	24
What's on the 500 Series™ Control Head	25
Key Functions	26
POWER/LIGHT Key ................................................................................................	26
VIEW Key................................................................................................................	27
MENU Key..............................................................................................................	27

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