Furuno 851 MARK-2 - Manual (Page 27)

2-18
10. Press the omnipad at 3 o'clock/9
o'clock to select M (meters), FA
(fathoms) or FT (feet) as desired and
press the [ENT] key.
11. Press the omnipad at 6 o'clock to
select Temp Unit.
12. Press the omnipad at 3 o'clock/9
o'clock to select °C or °F as desired
and press the [ENT] key.
13. Press the omnipad at 6 o'clock to
select STBY Display.
14. Press the omnipad at 3 o'clock/9
o'clock to select NORM (navigational
data is not displayed) or NAV
(navigational data is displayed as
desired) and press the [ENT] key.
15. Press the [MENU] key to escape.
2.23 Echo Stretch (magnifying
long range echoes)
Normally, the reflected echoes from long
range targets appear on the display as
weaker and smaller blips even though they
are compensated by the radar’s internal
circuitry. To stretch long range echoes, in
the range direction, turn on the echo
stretch function.
Echo stretch OFF Echo stretch ON
Distant echo
Figure 2-21 Echo stretch
Turning echo stretch on or off
1. Press the [MENU] key.
2. Press the omnipad at 6 o’clock to
select P/L, IR, NR & Radar Mode and
press the [ENT] key.
3. Press the omnipad at 6 o’clock to
select Echo Stretch.
4. Press the omnipad at 3 o’clock/9
o’clock to select ON or OFF as
appropriate.
5. Press the [ENT] key followed by the
[MENU] key. ES appears at the top
right side on the display when the echo
stretch feature is on.
Note 1: This function magnifies not only
targets but also sea clutter and
radar interference. For this reason
be sure the controls for adjustment
of sea clutter and radar interference
are properly adjusted before
activating the echo stretch.
Note 2: Echo stretch is inoperative on
ranges from 0.125 to 0.5 nautical
miles.
Note 3: When the echo stretch function is
selected, the equipment
automatically selects interference
rejection level #3 and turns on the
noise rejector. These can be turned
off via the menu if desired.