To Change Ping Speed; To Adjust Sensitivity - Eagle FISHMARK 640C Installation And Operation Instructions Manual

When using HyperScroll, you may also need to manually decrease the
sensitivity for optimum performance. Depending on water depth and
other conditions, HyperScroll may cause a second bottom echo to return
to the transducer during the next ping cycle or sounding.
This can result in a large amount of clutter appearing on the screen. If
this occurs, just decrease the sensitivity to a level that eliminates the
clutter. When you turn HyperScroll off, you can return to your original
sensitivity level.
Sonar Menu (left) with Ping Speed command selected.
Ping Speed Control Bar (right) at default setting.

To change Ping Speed:

1. From the Sonar Page, press
2. The Ping Speed Control Bar appears. Press ↑ to increase ping speed;
press ↓ to decrease speed. When it's set at the desired level, press

To adjust Sensitivity:

1. From the Sonar Page, press
|↓ to
MENU P
ING
| .
MENU ENT
73
| .
S ENT
PEED
.
EXIT