The 400TX shows Zoom range in conjunction with the
full depth range. 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. The area which is
being enlarged by Zoom is indicated by the square
box. 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.
"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. "Manual" Zoom provides detailed information
of any area from the surface to the bottom.
In "Manual" Zoom, the Zoom range does not move as the terrain changes.
To operate Zoom, press MENU repeatedly until the Zoom menu is on-screen. Three options are
available: "Off" (Factory Setting), "Auto" (Automatic bottom tracking Zoom), and "Manual" (User
controlled Zoom range). Press the DOWN ARROW once to highlight Auto or twice to highlight
Manual. If Manual is selected a submenu will appear allowing manual zoom range adjustment.
When the menu disappears, full range information is displayed on the right as always. The square
box indicates the Zoom range. In Auto Zoom, the box will move vertically to remain in the general
area of the bottom return. The left side of the screen is a magnified view of the information seen
inside the Zoom range box. The upper and lower depth limits of the Zoom range are shown on
the right side of the Zoom view.
