Furuno FSV-84 manual Noise limiter

4. SLANT MODE

4.10.5Noise limiter

Weak, unwanted reflections, colored light-blue or green, appear when the water is dirty, plankton layers exists, or due to ship’s noise. The noise limiter can reduce the effects of these unwanted reflections. Raising the setting causes unwanted reflections to be displayed in colors of blue to background color. Normally a setting of 3 or 4 is sufficient.

1.Press the [MENU] key to open the menu.

2.Select the S-SCAN SETTING menu and press the [MENU] key

3.Select NOISE LIMITER and press the [MENU] key.

4.Adjust setting from the dialog box as appropriate and press the [MENU] key. The setting range is 0-15. The higher the setting the greater the degree of suppression.

5.Select QUIT and press the [MENU] key.

6.Select QUIT at the top of the menu screen and press the [MENU] key to close all menus.

4.10.6Echo average

Adjusts echo afterglow, which can be useful for watching echo movement in the S-SCAN SETTING menu. The setting range is 0-7. The higher the number the longer echoes remain on the screen.

4.10.7Reverberation reduction

You may choose the length of reverberation for the echo signal in the S-SCAN SETTING menu. The larger the value the shorter the reverberation, which makes it easer to see the echo signal. The setting range is 0-3.

4.10.8Suppressing gain of bottom echo

None-moving echoes such as bottom echo, plankton echo, etc., may be suppressed by the setting of BOTTOM SUPPRESS in the H-SCAN SETTING menu (moving echoes such as fish school are not effected by this setting). The setting range is 0 to 10. The greater the setting, the greater the suppression level of the bottom, etc.

Note: Too high a setting may suppress slow-moving fish school as well.

4.10.9Suppressing sidelobes

Sidelobes are fairly emissions generated outside the main beam. The energy of the sidelobe is fairly weak but when the water is comparatively shallow and the bottom is rocky and hard, strong signals are detected by the sidelobe.

To reduce the effect of sidelobes, adjust SIDELOBE SUPPRESS from the S-SCAN SETTING menu. The setting range is –3 to +3 and the default setting is 0. The higher the setting the greater the sidelobe suppression. If there is a difference between the port and starboard side images, use a minus setting.

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