Eagle Electronics 642c User Manual

54

Fish Alarm

Use the fish alarm for a distinctive audible alarm when fish or other
suspended objects are detected by the Fish I.D.

 feature. Fish I.D.

must be turned on for the Fish Alarm to work. A different tone sounds
for each fish symbol size shown on the display.

Sonar Alarms menu with Fish Alarm selected. The check box to the left

is blank, indicating the alarm is turned off.

2. From the Sonar Alarms, press 

↓ to 

|

.

3. To turn off the alarm, highlight 

and press 

.

Press 

 repeatedly to get back to the main page display.

Calibrate Speed

The speed sensor can be calibrated to compensate for inaccuracies. Be-
fore you change the setting, calculate the percentage the speed is off.
You will enter this percentage in a moment.

If you figure the sensor is reading 10 percent faster than actual speed,
you will enter -10 in the calibration window. If the sensor is reading 5
percent slower than true speed, you will enter + 5 in the window.

A good way to gauge your speed sensor's performance is to compare its
reading with the ground speed measured the GPS function. When you
make a run to compare GPS ground speed to speed sensor speed, per-
form your test in relatively calm water free of current, if possible.

1. Press 

|

|

↓ to 

|

|

↓ to 

|

.

2. Enter the number you calculated earlier. Press 

↑  ↓ to change the

first character (+ or –), then press 

→ to move the cursor to the next

number and repeat until the percentage is correct. Press 

.