Furuno 1942 MARK-2 - Manual (Page 17)

2-5
2.10 Erasing the Heading
Marker, North Marker
The heading marker or north marker (avail-
able with gyrocompass connection) may oc-
casionally mask a target. To view the target,
you can temporarily erase the heading
marker and north marker by pressing and
holding down the [GAIN (HM OFF)] control.
Release the control to re-display the mark-
ers.
Heading
marker
North
marker
Figure 2-5 Heading marker and north marker
2.11 Measuring the Range
You can measure the range to a target three
ways: by the range rings, by the cursor, and
by the VRM (Variable Range Marker).
Measuring range by range rings
Count the number of rings between the cen-
ter of the display and the target. Check the
range ring interval and judge the distance of
the echo from the inner edge of the nearest
ring.
Measuring range by cursor
Operate the omnipad to place the cursor in-
tersection on the inside edge of the target
echo. The range to the target, as well as the
bearing, appears at the bottom of the display.
Measuring range by VRM
1. Press the [EBL/VRM SELECT] key to cir-
cumscribe a VRM readout (at the bottom
right-hand corner). Each press of the key
selects the readout of EBL1, EBL2, VRM1
or VRM2 in that order.
EBL
345.6°R
23.0°R VRM
5.3°NM
12.5°NM
Figure 2-6 Display bottom, showing
location of EBL and VRM readouts
2. Press the [EBL/VRM CONTROL] key to
enable control of the VRM by the
omnipad.
3. Operate the omnipad to place the outside
edge of the VRM on the inside edge of
the target. The omnipad must be oper-
ated within five seconds after pressing the
[EBL/VRM CONTROL] key, otherwise the
VRM cannot be operated.
4. Check the VRM readout at the bottom
right-hand corner of the display to find the
range to the target.
5. To anchor the VRM, press the [EBL/VRM
CONTROL] key.
To erase the VRM, press and hold down the
[EBL/VRM CONTROL] key about two sec-
onds.
VRM1
VRM2
6.0 NM
2.0
Range
Range ring
interval
Target
Cursor
Cursor range 4.0 NM
VRM
4.0 NM
3.0 NM
VRM1
range
VRM2
range
Figure 2-7 Measuring range by the cursor,
range rings and VRM
Note:
You can display the range readout of
the VRM and cursor in nautical miles, stat-
ute miles or kilometers. For details see the
next chapter.