1.8 Automatic Operation
Automatic operation is useful when you are preoccupied with other tasks and do not have time to adjust the display.
How it works
The automatic function automatically selects the proper gain and range scale according to depth. It works as follows:
•The range changes automatically to locate the bottom on the lower half of the screen. It jumps to one step shallower range when bottom echoes reach a halfway point of the full scale from top and to one step deeper range when they come to the lower edge of the scale.
•The gain is automatically adjusted to dis- play the bottom echo in
•Clutter level (on the User menu), which suppresses low level noise, is automatically adjusted.
Two types of automatic modes
Two types of automatic modes are available: cruising and fishing. Cruising is for tracking the bottom; fishing is for searching fish schools. Since cruising uses a higher clutter rejection setting than fishing, it is not recom- mended for fish detection – weak fish echoes may be deleted by clutter rejection.
How to enable automatic operation
1.Push the GAIN control. The auto mode display appears.
AUTO MODE
▲OFF CRUISING
▼FISHING
Figure 1-19 Auto mode display
2.Push the GAIN control again to select Cruising or Fishing.
1.9Selecting 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 hori- zontally on the screen and a slow advance speed will contract it.
1.Press the ZOOM and SIG LEV keys to- gether. The following display appears.
ADVANCE
▲STOP 1/16 1/8 1/4 1/2 1/1
▼2/1
Figure 1-20 Picture advance
speed selection display
The fractions in the menu denote number of scan lines produced per transmission. For example, 1/8 means one scan line is produced every 8 transmissions. STOP freezes the display and it is convenient for observing an echo.
2.Press the [▲] or [▼] key to select speed desired.
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