NorthStar Echo Sounder 491 Operation Manual page 71

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491 Echo Sounder Operations Manual
491 Features and Specifications
Table 4: 491 echo sounder features
Performance characteristics
Output
Alarms
Update rate
Auto modes
Zoom modes
Features
Single/Dual Channel, 50/200kHz, 600W
Fish, seabed, temperature
10 Hz maximum (depends on water depth)
Fishing and cruising
Marker, bottom, bottom lock, bottom lock/center
Mark present or past echo as waypoint (961/962)
Go directly to any past echo
A-scope analyzes present or past echoes
Navigation data shown at bottom of screen
Demo mode for training
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