Furuno FSV-30, Operator'S Manual

Page: 45 / 190

2. HORIZONTAL MODE
2-15
2.7.2 By decreasing pulselength
The pulselength 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 pulselength in order to separate fish echoes from
bottom reflections. Decrease the pulselength setting to shorten the pulselength.
For search of surface and midwater fish in which bottom reflections are not so
strong, use the longest pulselength “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 pulselength.
5. Select QUIT and press the [MENU] key to conclude.
6. Select QUIT at the top of the menu screen and press the [MENU] key to
close all menus.
2.7.3 2
nd
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 2
nd
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 2
nd
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 to conclude.
6. Select QUIT at the top of the menu screen and press the [MENU] key to
close all menus.