Furuno MODEL CSH-73 - Manual (Page 51)

7-7
Detecting Fish Schools Aurally
Sometimes you may be preoccupied with other tasks and unable
to concentrate on watching the sonar picture. In such cases it
would be a good choice to use the audio function. This function
enables you to monitor echoes from fish schools and seabed
through the built-in speaker.
After you’ve become accustomed to monitoring fish aurally, you
should be able to detect a fish school from a range longer than
you can detect it on the screen. In addition you may judge whether
the fish school is approaching or going away; the tone becomes
higher when the school is approaching and lowers when the
school is going away.
1. Operate the trackball to place the trackball mark to the direc-
tion you want to monitor through the speaker.
2. Press the R/B key. The bearing mark appears on the display.
Echoes in a 30
°
, 60
°
, 90
°
, 180
°
or 330
°
sector centering the
bearing mark are monitored through the speaker. You can
adjust speaker volume with the AUDIO control.
3. To change coverage area, open the data setting window (sub
panel 2) and change width of AUDIO SECTOR.
4. To scan the coverage area, open the data setting window,
turn on AUTO SCAN and set scanning WIDTH.
Note: You can display the signal monitored through the loud-
speaker on the history display combination window by pressing
the HIST key, if AUDIO is selected on the HIST Window DSP
menu in the USER menu.