Humminbird 400TX manual

www..reelschel matic..com

Range, Depth Alarm and Zoom. See the detailed description of each function for further explanation.

Menu Functions

Sensitivity. The Sensitivity function controls the sensitivity of the sonar receiver. The 400TX automatically adjusts the level of receiver sensitivity based on a number of factors including the depth of the water and the level of noise present. Noise can be caused by other electronic devices, engines, trolling motors, propeller cavitation and hydrodynamic flow among others.

The user has the option of adjusting the Sensitivity higher or lower based on personal preference. You can select one of 11 sensitivity settings from -5 to +5. A setting of 0 (factory setting) has no effect on the automatic sensitivity control. Increasing the sensitivity (+1 through +5) enables the unit to display the information from progressively smaller sonar returns. By decreasing the sensitivity (-1 through -5), the unit effectively filters small sonar returns.

In murky or muddy water, it is often helpful to reduce the sensitivity. This prevents the display from being cluttered with sonar returns from debris

or suspended particles. In very clear or very deep water, it may be helpful to increase the sensitivity since even the smallest sonar return may be of interest to the user.

To adjust Sensitivity, press MENU repeatedly until the Sensitivity heading is displayed. When the Sensitivity menu appears, use the UP ARROW to increase the sensitivity, or the DOWN ARROW to reduce sensitivity. To sequence through the available settings, press and hold either ARROW button. Release the button at the setting you want to select.

After an adjustment is made, the menu disappears and the new sensitivity setting is in affect. If additional time is needed to study a menu, press and hold the MENU button and the menu will remain onscreen indefinitely. If you need to make an additional adjustment, press the UP ARROW or DOWN ARROW button.

Depth Range. The Depth Range function controls the vertical distance displayed on the graphic area of the display. There are nine depth ranges available. The top of the range is always 0, or the surface of the water. Ranges of 0-15', 0-30', 0-60', 0-120', 0-180', 0- 240', 0360', 0-480', and 0-600' are available. In the metric version, ranges of 0-5, 0-10, 0-20, 0-40, 0-60, 0-80, 0-110, 0-150, and 0-185 meters are available. The range that positions the bottom depiction closest to the bottom of the screen, will best utilize the available display resolution.

The 400TX automatically adjusts the depth range depending on the depth of the water. The unit tries to maintain the bottom depiction about 2/3 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.