Eagle Electronics 642c Fish Finder User Manual


 
48
Sonar Operations
As you can see from the quick reference, basic operation is pretty easy, right
out of the box. If you are a sonar novice, try operating the unit with the de-
fault settings until you get a feel for how it is working.
As you are learning the basics, there is one setting you might want to
tinker with from time to time — Sensitivity.
Sensitivity controls the unit's ability to pick up echoes. If you want to see
more detail, try increasing the sensitivity, a little at a time. There are situa-
tions when too much clutter appears on the screen. Decreasing the sensitivity
can reduce the clutter and show the strongest fish echoes, if fish are present.
As you change the sensitivity setting, you can see the difference on the chart
as it scrolls.
These figures show results of different sensitivity levels on the same lo-
cation. Fig. 1: Sensitivity at 88 percent, determined by Auto Sensitivity.
Typical of full auto mode. Fig. 2: Sensitivity set at 75 percent. Fig. 3: Sen-
sitivity set at 50 percent. Fig. 4: Sensitivity set at 100 percent.
You can change the sensitivity level whether you are in Auto Sensitivity
mode or Manual Sensitivity mode. The adjustment method works the
same in both modes, but it gives you slightly different results.
Fig. 1
Fig. 2
Fig. 3
Fig. 4