Eagle Electronics 640C, 640cDF manual Basic Sonar Quick Reference

Basic Sonar Quick Reference

1.Mount the transducer, antenna and unit. Connect the unit to electric power and the transducer. (If GPS operation is desired, connect GPS antenna, too.) Make sure the MMC is in. (See complete installation de- tails beginning on page 6.)

2.Launch your boat.

3.To turn on the unit, press and release PWR key.

4.Opening screen displays Map Page. Rotate through the four main

Page screens (Map Page, Satellite Status Page, Navigation Page, Sonar Page) by pressing PAGES← → to select Page NameEXIT. Switch Pages to display Sonar Page.

5.If GPS data is desired, wait while unit locates satellites and calculates current position. When the unit acquires position, a tone sounds and a posi- tion acquired message appears.

6.With position acquired, head for your fishing grounds. Your unit will automatically display digital depth and surface water temperature in the top left corner of the screen.

The auto settings will track the bottom, displaying it in the lower por- tion of the screen. The full sonar chart will scroll from right to left, showing you what's under the boat as you cruise across the water. You can change the display by:

Zoom in to enlarge the chart for more detail: press ZIN.

Zoom out to return to full chart mode: press ZOUT.

7.Watch the display for the appearance of fish symbols (or arches, if Fish I.D. is turned off). When you see fish symbols or arches, you've found fish! Stop the boat and get your lure or bait into the water at the depth indicated on the sonar chart.

8.Gauge the fish depth by visually comparing the fish symbols or

arches with the depth scale on the right side of the screen, or get a more accurate measure with the Depth Cursor. Press MENU↓ to DEPTH CURSORENT. Press ↓ ↑ to align the cursor line with the fish arch. The exact depth appears in a box at the right end of the cursor line. To clear the cursor, press EXIT.

9.If you are drifting at a very low speed or anchored, you are not mov- ing fast enough for a fish to return the tell-tale fish arch signal. As you drift over a fish, or as a fish swims through the transducer's signal cone, the fish echo will appear as a straight line suspended between the surface and the bottom when Fish I.D. is turned off.

10.To turn off the unit, press and hold PWR key for three seconds.

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