NorthStar Navigation Explorer 660 - Manual (Page 71)

Northstar Explorer 660 Installation and Operation Manual 71
B-2 GPS navigation problems
2-1 No GPS fix or long time to get fix
at startup:
a May occur occasionally if the antenna does
not have a clear view of the sky. The satellite
positions are constantly changing.
b Antenna cable not connected to display unit.
2-2 Explorer 660 GPS position different from
true position by more than 10 m (33 ft):
a Explorer 660 in simulate mode. Turn simulate
mode off (see section 15-14).
b The normal error in GPS position will exceed
10 m (33 ft) for about 5% of the time.
c Under special circumstances the US
Department of Defence may introduce a
deliberate and changing error in the GPS
positions of up to 300 m (1000 ft).
2-3 Explorer 660 position different from same
position on local charts:
a Explorer 660 in simulate mode. Turn simulate
mode off (see section 15-14).
b Incorrect chart datum. Select the correct
chart datum (see section 15-2).
c Map shift has been applied wrongly. Clear map
shift, then reapply if necessary (see section 15-2).
2-4 Can not see boat on chart:
Press ESC to switch to centre on boat mode
(see section 3-2).
2-5 The time or date on satellite display is
wrong or off:
a No GPS fix.
b In simulate mode. Turn simulate mode off
(see section 15-14).
c Local time offset is wrong (see section 15-12).
The Local Time Offset must be changed
when daylight saving time starts or ends.
2-6 Autopilot not responding to Explorer 660;
no NMEA output:
a NMEA output disabled or the required NMEA
sentences are not turned on. Check NMEA
settings (see section 15-9).
b Check that the instrument is
connected correctly.
2-7 No DGPS fix or loss of DGPS fix:
a To receive a DGPS fix, WAAS/EGNOS must be
enabled or an optional DGPS antenna fitted
(see section 7).
b With WAAS/EGNOS: Boat out of coverage
area (see section 7).
c With WAAS: GPS antenna does not have a
clear view of the horizon towards the equator.
d With beacon DGPS: boat out of range of a
DGPS beacon.
B-3 Sonar fishfinding problems
3-1 The Explorer 660 operates erratically:
a Check that the transducer does not have
debris (e.g. weed, plastic bag) caught
around it.
b The transducer may have been damaged
during launching, running aground or while
underway with debris etc. If the transducer
has been impacted, it may have been kicked
up on the bracket. If it is not physically
damaged, reset the transducer back to its
original position. (See the Transom Transducer
Installation Guide.)
c When the transducer is less that 2 ft (0.6 m)
from the bottom, the depth readings may
become inconsistent and erratic.
d Manual Gain may be set too low, which may
cause weak bottom echo or no fish signals. If in
Manual Gain, try increasing the Gain.
e Ensure the back of the bottom surface of the
transducer is slightly lower than the front and
the front is as deep in the water as possible
in order to minimize the generation of
bubbles through cavitation. (See the Transom
Transducers Installation Guide.)
f Check the transducer and power cable
connectors at the back of the display unit
are securely plugged in and the collars are
locked in place. The collars must be secure for
watertight connection.