Furuno 1834C-BB User Manual

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4. VIDEO SOUNDER OPERATION 
 
4-9
4.4  Measuring Depth, Time 
The VRM measures the depth and the cross-hair cursor, time. 
 
1. Rotate the ENTER knob to shift the VRM; counterclockwise to shift it downward, 
clockwise to shift it upward. You may also use the Trackball to shift the VRM.   
2. Roll the Trackball horizontally to adjust the cross-hair cursor to measure time. 
VRM (white)
 40.0
 
Depth to VRM
Cross-hair
cursor
LF
97
 
150
200
50
100
0
0'33"
Time for a scan line to travel
from the right edge of the 
display to the cross-hair cursor
 
How to measure depth and time 
 
Note:
 If, when the range setting is over 1000 ft (m, fa, p/b), the VRM indication and depth 
scale may overlap one another, shift the cross-hair cursor slightly to show them completely. 
Further, when the display is shifted, the depth scale may obscure the time indication. 
 
 
4.5 Reducing 
Interference 
Interference from other acoustic equipment operating nearby or other electronic equipment 
on your boat may show itself on the display as shown below. 
Interference from            Electrical inteference
other sounder
 
Types of interference 
To reduce interference, do the following: