Humminbird HELIX 9 Operation Manual page 34

Select a Down Imaging Frequency (HELIX DI GPS only)
In the HELIX DI GPS, you can choose a Down Imaging frequency that will be used for the Down Imaging View. For the best overall
image quality and depth, select 455 kHz. For the sharpest image (but limited depth capability), select 800 kHz.
1. Main Menu: Press the MENU key twice. Select the Sonar tab.
2. Select Imaging Frequency
3. Select 455 kHz or 800 kHz.
Set the Down Imaging Beam Width (HELIX SI GPS only)
In the HELIX SI GPS, you can set the width of the beam (side to side) used for the Down Imaging View. To see only the data directly
under your boat, select Narrow. Medium reveals more information, while Wide displays the maximum information available from the
Down Imaging beam width. See Down Imaging Overview for more information.
1. Main Menu: Press the MENU key twice. Select the Sonar tab.
2. Select Down Imaging Beam Width.
3. Press the RIGHT or LEFT Cursor keys to select a width.
Turn off Sonar
If you're using your control head for GPS/Navigation functions only, use these instructions to hide all sonar views from the view
rotation. When it is set to Off, this is setting also stops the unit from pinging, so all sonar operation is deactivated.
1. Press the POWER key.
2. Select Sonar.
3. Select Off.
NOTE: You can also turn on/off Sonar from the Main Menu > Setup tab > Sonar.
Set up Sonar 34
HELIX DI GPS Beam Select Options
for the Down Imaging View
45°
800kHz
75°
455kHz
16°
455kHz
28°
200kHz
75 Degree Total Coverage