Furuno FSV-84 manual Decrease pulse length, Adjust 2nd AGC

2. HORIZONTAL MODE

2.7.2Decrease pulse length

The pulse length determines the length of the transmission pulse emitted into the water. While a longer pulse is advantageous for long-range sounding, it has the disadvantage of being poor in discrimination of targets, that is, the ability to separate several closely located targets. When searching bottom fish, therefore, it is useful to shorten the pulse length in order to separate fish echoes from bottom reflections. Decrease the pulse length setting to shorten the pulse length. For search of surface and midwater fish in which bottom reflections are not so strong, use the longest pulse length “9”.

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

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

3.Select TX PULSE LENGTH and press the [MENU] key.

4.Adjust setting from the dialog box as appropriate and press the [MENU] key. The setting range is 0-9. The higher the setting the longer the pulse length.

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.

2.7.3Adjust 2nd AGC

While it is ideal to suppress bottom echoes with the AGC alone there are some fishing grounds where this is not possible. (The high power sonar has the advantage of long-range detection but this can also be a disadvantage, since weaker echoes may be hidden in strong, unwanted echoes such as the bottom.) If you cannot suppress bottom echoes or sea surface reflections by the AGC function alone, use the 2nd AGC feature. Normally a setting of 1 or 2 is suitable. For especially strong echoes, use a setting of 3 or 4.

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

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

3.Select 2nd AGC and press the [MENU] key.

4.Adjust setting from the dialog box as appropriate and press the [MENU] key. The setting range is 0-12. The higher the setting the greater the 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.

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