Furuno GD-1700C - Manual (Page 160)

4. VIDEO SOUNDER OPERATION
4-16
4.10 Picture Advance Speed
The picture advance speed determines how quickly the vertical scan lines run
across the screen. When selecting a picture advance speed, keep in mind that a
fast advance speed will expand the size of the fish school horizontally on the
screen and a slow advance speed will contract it.
The advancement speed may be set independent of or synchronized with ship’s
speed.
4.10.1 Advancement independent of ship’s speed
1. Press the [MENU] key.
2. Press the SOUNDER MENU soft key.
3. Select PICTURE ADVANCE, and press the EDIT soft key to open the picture
advance window.
PICTURE ADVANCE
▲
¤ 2/1
¡ 1/1
¡ 1/2
¡ 1/4
¡ 1/8
¡ 1/16
¡ STOP
▼
Picture advance window
4. Use the cursor pad to select speed desired. The functions in the window
denote the number of scan lines produced per transmission. For example,
1/8 means one scan line is produced every eight transmissions. STOP
freezes the display and it is convenient for observing an echo.
5. Press the RETURN soft key followed by the [MENU] key to close the menu.
Note:
For the C-MAP specification unit, when using the plotter/sounder
combination display, advancement of the sounder picture may be
temporarily interrupted while the plotter display is being shifted or its
display range is being changed.