Furuno MODEL CSH-73 manual Selecting a Display Range, Setting the Tilt Angle

Selecting a Display Range

Operate the RANGE control to select a display range. The range selected appears at the top center of the screen.

Setting the Tilt Angle

The tilt angle shows the direction to which the sound wave is emitted. When the sound wave is emitted horizontally, the tilt angle is said to be zero degrees and when emitted vertically, 90 degrees.

To set a tilt angle, operate the TILT lever.	R400 Tilt
Watch the tilt angle indication at the top right
	T 15	angle
corner on the screen. The tilt angle can be set
in one-degree steps from 0 to 90 degrees.

Finding a proper tilt angle is important when searching for fish.

The beam of the half-circle scanning sonar is fan shaped as in

(A)below and it swings up and down according to the setting of the TILT lever. If you look at the angle between the horizontal plane (sea surface) and several points on the beam, it can be seen that the angle is maximum in the center of the beam (q) and becomes smaller as it goes toward the edge, finally becoming zero degrees at the edge of the beam. This will be more clearly understood if you look at a vertically directed beam. See (B) below. You should keep in mind that the tilt angle displayed on the screen is the angle the center of the beam forms with the horizontal plane.

θ

(A) (B)

Figure 2-1 Tilt angle

2-3