Humminbird 128 manual Depth Range

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 bias, or the DOWN ARROW to reduce sensitivity bias. By holding either ARROW button depressed, the unit will sequence through the available settings until you release the button or the end of the adjustment range is reached. If additional time is needed to study a menu, press and hold the MENU button and the menu will remain on-screen indefinitely.

If a setting limit is reached, the ARROW symbol attached to the menu appears to be hollow which indicates that the related button has no further function. Also, the audible "error" consisting of multiple chirps will be heard.

After an adjustment is made, the menu disappears and the new sensitivity setting begins to affect new sonar information as it flows on-screen. If additional adjustment is needed, the UP ARROW or DOWN ARROW can be pressed without having to first press MENU.

Depth Range

The Depth Range function controls the vertical distance displayed on the graphic area of the display. There are 9 different 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' , 0-360' , 0-480' , and 0-600' are available. The range which positions the bottom depiction closest to the bottom of the graphic area of the display, will best utilize the available display resolution.

The Wide 128 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' of water, the 0-30' range would be selected). This provides the best display resolution and therefore the best target separation possible.

The Depth Range can be adjusted manually. Press MENU repeatedly until the Depth Range menu is visible. The two options available are "Auto" (Factory Setting) and "Manual". Pressing the DOWN ARROW enables "Manual" depth range control and an additional menu will appear which allows the user to adjust the current depth range setting. If no further button is pressed, the current depth range is selected as the desired range and the unit returns to normal operation.

Using "Manual" Depth Range control, the user can view sonar information from the area near the surface in great detail. If a depth range other than the current range is desired, pressing the DOWN ARROW to highlight "Adjust" will allow selection of one of the 9 available ranges. Simply press and hold the UP or DOWN ARROW button to scan through the available options. If a setting limit is reached, the audible "error" or multiple chirps will be heard and no further adjustment is allowed.

When "Manual" range is used, the unit no longer adjusts the Depth Range to the most appropriate range for bottom display. Often, the bottom may not be visible on-screen. The digital depth readout always determines the depth of the bottom, even if it is not visible on-screen.

When a Depth Range is selected manually and the Depth Range menu is still active (most recently used), further adjustment of the depth range

can be achieved by simply pressing the appropriate UP or DOWN ARROW button. The button press will bring the Depth Range menu on-screen and allows immediate adjustment of the range.

To return to "Automatic" Depth Range control, press the MENU button until the Depth Range menu appears on-screen and use the UP ARROW to select AUTO. The Wide 128 returns to Automatic operation.