Furuno Ls4100 manual Erasing Weak Echoes, Scope Display, Appearance of weak echoes, Scope display

1.12Erasing Weak Echoes

Sediment in the water or reflections from plankton may be painted on the display in low intensity tones.

Weak echoes

1.13 A-scope Display

This display shows echoes at each transmission with amplitudes and tone proportional to their intensities, on the right 1/4 of the screen. It is useful for estimating the kind of fish school and bottom composition.

Note: In the dual frequency display, the A-scope display is only available with the high frequency display.

Single frequency display

Appearance of weak echoes

These weak echoes may be erased as follows:

1.Press the [MENU/ESC] key to open the main menu.

2.Use ▲ or ▼ to choose SIGNAL LEVEL from page 1 of the menu.

3.Press ► to show the options window.

4.Use ▲ or ▼ to choose the degree of suppression desired; Off, Low, or High (highest).

5.Press the [MENU/ESC] key to close the menu.

To turn off the signal level function, choose "Off" at step 4 and then press the [MENU/ESC] key.

50k 1/1

		Weak
	10
		reflection
		(fish or noise)
	20	Strong
		reflection
	30	(fish)
32.3	40	Strong
		reflection
	A-scope display	(bottom)

A-scope display

1.Press the [MENU/ESC] key to open the main menu.

2.Press ▲ or ▼ to choose A-SCOPE from page 1 of the menu.

3.Press ► to show the options window.

4.Press ▲ or ▼ to choose the A-scope presentation type desired. Normal: Display shows echoes at each transmission with amplitudes and tone proportional to their intensities.

Peak: Peak-hold amplitude picture.

5.Press the [MENU/ESC] key to close the menu.

To turn off the A-scope display, choose Off at step 4 and then press the [MENU/ESC] key.

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