User manual HUMMINBIRD 250DX DUAL BEAM

[. . . ] Operations Manual THANK YOU Thank you for choosing Humminbird, America's #1 name in fishfinders. Humminbird has built its reputation by designing and manufacturing top-quality, thoroughly reliable marine equipment. Your Humminbird is designed for trouble-free use in even the harshest marine environment. In the unlikely event that your Humminbird does require repairs, we offer an exclusive Service Guarantee - free of charge during the first year after purchase, and available at a reasonable rate after the one-year period. [. . . ] If you need to make an additional adjustment, press the UP ARROW or DOWN ARROW button. High(+) Sensitivity Low(-) Sensitivity Sensitivity at "0" 14 USING THE 250DX MENU FUNCTIONS Depth Range. The Depth Range function controls the vertical distance displayed on the graphic area of the display. Ranges of 0­15', 0­30', 0­60', 0­120', 0­180', 0­240', 0­360', 0­480', and 0­600' are available. In the metric version, ranges of 0­5, 0­10, 0­20, 0­40, 0­60, 0­80, 0­110, 0­150, and 0­185 metres are available. The range that positions the bottom depiction closest to the bottom of the screen, will best utilize the available display resolution. The 250DX automatically adjusts the depth range depending on the depth of the water. The unit tries to maintain the bottom depiction about ²/ down the total range (for example, in 20' (6m) of water, the 0-30' (0-10m) range would be selected). This provides the best display resolution and therefore the best target separation possible. The manual setting enables you to adjust the current depth range setting. The unit no longer adjusts the Depth Range to the most appropriate range for bottom display. The digital depth readout always determines the depth of the bottom, even if it is not visible on-screen. Using manual Depth Range control, you can view sonar information from the area near the surface in great detail. 15 USING THE 250DX MENU FUNCTIONS To return to automatic Depth Range control, press the MENU button until the Depth Range menu appears onscreen and use the UP ARROW to select AUTO. Zoom is similar to Depth Range because it controls the range of information displayed on screen. Zoom, however, allows selection of ranges beneath the surface so any area of water between the surface and the bottom can be enlarged to provide more detailed information. By using the full display to show a small area of coverage, the effective display resolution is increased, and the unit's ability to separate close targets is enhanced. Depth Range There are four Zoom ranges available: 2m (7¹/'), 5m (15'), 10m (30'), and 20m (60'). These ranges are not directly user controlled but are instead dependent on the current depth range. In shallow water, when the 5m (15') or 10m (30') range is in use, the Zoom range is 2m (7¹/'). If the 20m (60') or 40m (120' ) range is in Upper Zoom Limit use, the Zoom range is 5m (15'), if a 60150m (180'-480') depth range is in use, the Zoom range is 10m (30'), and if the 185m (600') range is in use, the Zoom range is 20m (60'). The Zoom range is shown on the left side of the screen and full range information is shown on the right side of the display. Zoom can either operate automatically, in which the Zoom range is constantly adjusted to show the bottom, or manually, in which the user controls the location of the Zoom range. 16 Lower Zoom Limit USING THE 250DX MENU FUNCTIONS Automatic Zoom is especially helpful when looking for structure or bottom detail. The Automatic Zoom keeps the bottom in view even in quickly changing terrain, but is most useful in flatter areas without considerable depth variation. Manual Zoom provides detailed information of any area from the surface to the bottom. When the range is shown in the menu, the upper number represents the top of the current Zoom range. [. . . ] Also, in very deep water, it may be necessary to manually increase the sensitivity setting to maintain a graphic depiction of the bottom. 27 MAINTENANCE TROUBLESHOOTING If you are using a transducer switch to connect two transducers to the 250DX, ensure the switch is in the correct position to connect a transducer that is in water. (If a trolling motor transducer is selected and the trolling motor is out of water, no sonar information appears. ) If none of the above solve the problem, inspect the transducer cable from end to end for breaks, kinks, or cuts in the outer casing of the cable. If the transducer is connected to the unit through a switch, temporarily connect it directly to the unit and try again. If none of these items identifies an obvious problem, the transducer itself may be the problem. [. . . ]