Furuno GP-3700F, Operator'S Manual

Page: 154 / 224

11. ECHO SOUNDER
11-6
Peak hold display
The peak hold function shows “normal” A-scope display plus peak-hold amplitude pic-
ture in dots. The peak hold is cleared every five seconds.
Note: When the strong echo appears after weak echo at the same depth, the peak-
hold amplitude picture is updated. When the weak echo appears after strong echo at
the same depth, the peak-hold amplitude picture is not updated because strong echo
remains.
1. Press the MENU key to open the main menu.
2. Select [9. ECHO SOUNDER SETTING].
3. Select [0. A-SCOPE PEAK HOLD].
4. Select [SHOW].
5. Press the
DISP key to close the menu.
To deactivate the peak hold display, select [HIDE] at step 4.
11.2.8 Mix display
This mode compares echo intensity between low and high frequencies, and displays
echoes from tiny fish in discriminative colors. This is done by utilizing the fact that tiny
fish return a stronger echo against a high frequency rather than a low frequency. This
is done as below.
• If a high frequency echo is stronger than the corresponding echo on the low fre-
quency, the high frequency echo is displayed.
• If the low frequency echo is stronger than or equal to the high frequency echo, it is
less likely to be a tiny fish and therefore is displayed in blue.
• If the echoes on both frequencies have the intensity corresponding to reddish brown
or red, they are displayed in reddish brown or red: this is necessary to display the
zero line and bottom in reddish brown or red.
In other words, the echoes displayed in orange thru light-blue may be considered to
be tiny fish such as whitebait. [50/200] is displayed at the bottom left of the mixed
screen.