Furuno NAVNET 1724C - Manual (Page 138)

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 Cursor pad to shift the VRM.
2. Roll the Cursor pad 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: