O P E R A T I O N
14
Operation
Mobile Operation
Normally the front of the LD-250 antenna needs to face north. In a mobile
situation the orientation of the antenna would be constantly changing as the
vehicle turns. The LD-250 has the ability to correct for this by using heading data
from a GPS or marine compass.
As long as you are moving forward your GPS will know which direction you are
traveling and, at least for an automobile, which direction your vehicle is facing.
The GPS looks for change in location to calculate your heading. Since a boat can
change directions without necessarily changing position (rotating on its anchor for
example) a marine compass is recommended for marine applications.
GPS/Compass Connection
The LD-250 has a NMEA port on the read panel to connect to a GPS or compass
for mobile operation. A GPS or marine compass connection is required for
mobile use since the LD-250 needs to know which direction the antenna is
pointed.
GPS /COMPASS WIRE CONNECTIONS
BLUE
NMEA data +
YELLOW
no connection
GREEN
NMEA data in –
RED
+12V to power GPS or compass
BLACK
Ground for GPS or compass
WHITE
NMEA data out (not implemented)
If your GPS does not provide a NMEA Data – connection you should connect
the LD-250’s NMEA Data – (green wire) to ground (black wire).
Chapter
2
