Eagle Electronics 642c Fish Finder User Manual


 
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SENSITIVITY|ENT| to SENSITIVITY|ENT. Press to pick a different
sensitivity setting. When it is set at the desired level, press
EXIT.
Tip:
While you are experimenting and learning, it is possible to scramble
the settings so the sonar picture disappears from your screen. If that
happens, remember it is easy to switch back to full automatic opera-
tion by restoring the default settings.
To Restore Default Settings:
1. Press
MENU|MENU| to SYSTEM SETUP|ENT| to RESET OPTIONS|ENT.
2. A confirmation message will appear. Press to
YES|ENT. All options
are reset and the unit reverts back to the Map Page at the 4000-mile
zoom range. Recorded sonar logs or GPS data will be unchanged.
Fish Symbols vs. Full Sonar Chart
You may have noticed in the quick reference we used fish arches in full
sonar chart mode for our example and not the popular Fish I.D. fish
symbol feature. Here's why.
Fish I.D. is an easier way for a sonar novice to recognize a fishy signal
return when he sees it. However, locating fish by symbol only has some
limitations.
Your sonar unit's microprocessor is remarkably powerful, but it can be
fooled. Some of the echoes calculated to be fish could be tree limbs or tur-
tles! To see what's under your boat in maximum detail, we recommend
you turn off Fish I.D. and begin learning to interpret fish arches.
Fish I.D. is most handy when you are in another part of the boat or per-
forming some task that prevents you from watching the sonar screen.
Then, you can turn on Fish I.D. and the audible fish alarm. When that
lunker swims under your boat, you will hear it!
Fish I.D. can also be useful when you want to screen out some of the
sonar detail gathered by your unit. For example, in one case fisherman
in San Francisco Bay saw clouds of clutter in the water but no fish
arches. When a down rigger was pulled up, it brought up several small
jellyfish. The fisherman switched their sonar to Fish I.D., which
screened out the schools of jellyfish and clearly showed the game fish
there as fish symbols.
The sonar options section discusses Fish I.D., fish alarms and other
features in greater detail.