Furuno FSV-30, Operator'S Manual

Page: 88 / 190

3. VERTICAL MODE
3-8
V-SCAN SETTING
TX PULSE LENGTH
TVG-NEAR
: 7
: 0
TVG-MEDIUM
TVG-FAR
NOISE LIMITER
AGC
ECHO AVERAGE
: 0
: 0
: 2
: 0
MENU QUIT
INT REJECT
: 0
: 0
QUIT
OTHERS...
REVERBERATION : 0
FREQ SHIFT : 0
2ND AGC : 0
NEAR AGC : 0
BOTTOM SUPPRESS : 0
V-SCAN SETTING menu
3. Select TVG-NEAR with the trackball and press the [MENU] key.
QUIT
CANCEL
TVG setting dialog box
4. Use the trackball to select
S
(raise setting) or
T
(lower setting) and press
the [MENU] key. The setting range is –5 to 5. The higher the setting the
further the TVG works.
5. Select QUIT and press the [MENU] key to conclude.
6. Repeat steps 3 and 4 to set TVG-MEDIUM and TVG-FAR.
When sea surface reflections or plankton layers disturb the picture, decrease
appropriate TVG option by one or two steps.
7. Select QUIT at the top of the menu screen and press the [MENU] key to
close all menus.
When a fish school is located on a long range setting (about 800 meters)
and is approaching own ship do as follows:
Adjust the tilt to keep the fish school in the center of the sonar beam, namely,
fish school is displayed in strongest colors possible. Confirm that the fish
echo is displayed in the same color as it approaches. If the color suddenly
changes to weaker colors as the fish enters MEDIUM and NEAR areas, the
TVG is improperly set. Adjust the TVG. If this again produces sea surface
reflections and noise try to remove them with AGC and NL controls.
Note: If the above procedure does not produce satisfactory results, the
TVG curve can be changed on the V-SCAN SETTING menu. Also
refere to paragraph 3.8.4 “Near AGC”