Sweep Timing; Adjusting Video Signal Level - Furuno FR-1500 MARK-3 Series Installation Manual

5.4 Sweep Timing

Sweep timing differs with respect to the length of the signal cable between the
scanner unit and the display unit. Adjust sweep timing for both main display and
sub display. Adjust sweep timing for both main display and sub display (if in-
stalled). Adjust sweep fiming at installation to prevent the following symptoms:
• The echo of a "straight" target (for example, pier), on the 0.25 nm range, will
appear on the display as being pulled inward or pushed outward. See Figure
5-5.
• The range of target echoes will also be incorrectly shown.
Figure 5-5 Examples of correct and incorrect sweep timings
1. Press [MENU] [0] [0] [0] [0] [5] [5] [3] to select TIMING from page 1 of the SET
UP menu.
2. Transmit on the 0.25 nm range.
3. Adjust radar picture controls to display picture properly.
4. Select a target echo which should be displayed straightly.
5. Adjust the VRM control to straighten the target echo. (The figures to the right
of "TIMING" are the amount in nautical miles the target is "straightened.")
6. Press the [ENTER/SELECT] key to register.

5.5 Adjusting Video Signal Level

When the signal cable is very long, the video amplifier input level decreases,
shrinking target echoes. To prevent this, adjust the video level, either automati-
cally or manually. Adjust it after adjusting tuning and sweep timing and do it on
long range. Adjust video signal level for both main display and sub display.
Automatic adjustment
1. Turn off the A/C AUTO control.
2. Transmit on long range.
3. Display page 1 of the SET UP 1 menu.
4. Press the [4] key to select AUTO from the VIDEO LVL field.
(1) Correct (2) Target pushed
inward
(3) Target pushed
outward
5-3