Measuring Range By The Variable Range Marker (Vrm) - Furuno FCR-2107 Series Operator's Manual

2.11.2

Measuring range by the variable range marker (VRM)

There are two VRMs, No. 1 and No. 2, which appear as dashed rings so that you can discriminate them from the
fixed range rings. The two VRMs can be distinguished from each other by different lengths of dashes.
From the control unit w/keyboard
1. Push the VRM ON key to display either of the VRMs. Successively pushing the VRM ON key toggles the
active VRM between No. 1 and No. 2. The currently active marker is enclosed with >.....<.
2. Operate the VRM rotary control to align the active variable range marker with the inner edge of the target of
interest and read its distance at the lower-right corner of the screen. Each VRM remains at the same
geographical distance when you operate the RANGE key or the RANGE box. This means that the apparent
radius of the VRM ring changes in proportion to the selected range scale.
3. Push the VRM OFF key to erase each VRM.
By trackball
1. Use the trackball to place the arrow in the VRM1 or VRM2 box, whichever VRM you want to use.
VRM boxes
2. The guidance area reads "VRM on/." Push the left button to turn on the VRM. The guidance area now reads "/L
= DELETE /."
3. Put the cursor on the VRM1 or VRM2 box, and spin the scrollwheel to align the marker with the inner edge of
the target. Each VRM remains at the same geographical distance when you operate the RANGE key. This
means that the apparent radius of the VRM ring changes in proportion to the selected range scale.
4. To erase a VRM, select the appropriate VRM box then push the left button until the VRM disappears from the
screen.
Showing the TTG-to-VRM indication
You can show the TTG to VRM location(s) as follows:
1. Open the main menu followed by the Initial Settings menu.
2. Put the cursor on the triangle in the menu to show the Operation menu.
3. Select TTG with VRM.
4. Spin the scrollwheel to select one of the following:
OFF: NO VRM TTG display
VRM1: Show TTG data on VRM1 indication
VRM2: Show TTG data on VRM2 indication
VRM1+VRM2: Show TTG data on both VRM1 and VRM2 indications.
5. Press the MENU key several times to close the menu.
TTG-to-VRM
VRM1
indication
Measuring range with VRMs
00:00
>3.682NM<
2. Radar Operation
2-17