Furuno FSV85MK2, Manual

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2. HORIZONTAL MODE
2-13
2.7.3 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 hid-
den 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 fea-
ture. Normally a setting of 1 or 2 is suitable. For especially strong echoes, use a setting
of 3 or 4.
1. Press the MENU/ESC key to show the main menu.
2. Select [Gain Setting] then push the left-click box.
3. Press the
H/V/S key to select the [H1] or [H2] tab.
4. Select [2nd AGC] then push left-click button.
5. Select [2nd AGC] again then push the left-click button.
6. Select

or

then push the left-click button to change the setting.
The setting range is 0 to 20. The higher the setting, the stronger the suppression
on long range.
7. Select [Quit] on the setting box then push the left-click button to close the box.
8. Long-press the
MENU/ESC key to close all menus.
Other AGC-related items on the [2ND AGC] menu
Distance : Set the start range for the 2nd AGC. The setting range is 0 - 2000 m, in 20
m increments. 2nd AGC is inoperative if the display range is lower than the 2nd AGC
start range.
Type : Select the TVG type for 2nd AGC. Select [Normal] for everyday use.
Post 2nd AGC-Near *: Set the near range threshold for [Post 2nd AGC]. The larger
the figure, the greater the suppression.
Post 2nd AGC-Far *: Set the far range threshold for [Post 2nd AGC]. The larger the
figure, the greater the suppression.
Post 2nd AGC-Dist *: Switch between Far and Near Post 2nd AGC.