Appendix C - Trouble Shooting Guide - Navman Tracker500/500i User Manual

Appendix C – Trouble Shooting Guide
PROBLEM
Tracker500/500i will not switch on.
Tracker500/500i switches itself off.
Some previously available
navigation functions are no longer
available. 'GPS FIX LOST'
message displayed.
Prolonged period to obtain a fix.
Position indicated on Tracker500/
500i varies by up to 100 metres
from true position.
Indicated speed does not match
the boat's speed/log instrument.
Tracker500/500i User Manual
CAUSE – SOLUTION
Power/data cable not connected or not not fully
connected into its socket.
Power supply connections reversed.
Check for a poor connection in the power cable
causing intermittant loss of power.
When the Tracker500/500i detects a large supply
voltage surge, it will turn itself off to protect itself.
Check for loose battery connections.
GPS no longer has a fix. This may occur occasion-
ally if the antenna does not have a clear view of the
sky. The satellite positions are constantly changing
so that their signals can come from any direction. It
is essential that the antenna has a clear view of the
sky.
This will occur if theTracker500/500i has been
moved more than 500 kilometres since it was last
switched on, or if it has not been used for several
months. The Tracker500/500i will automatically
'search' the sky for all available satellites. this may
take a few minutes. This function is fully automatic
and requires no user intervention. Subsequent
times to first fix should typically be 45 seconds.
The USA Department of Defence introduce a
varying offset known as Selective Availability (SA).
The direction and magnitude of the offset is
constantly varying. SA will cause errors typically of
0-100 metres, but can occasionally cause errors in
excess of 300 metres. The effects of SA can be
reduced with the installation of a differential
receiver, if this service is available in your area.
The constantly changing SA offset results in an
indicated speed error that is normally less than 1
knot, but occasionally exceeds 1.5 knots. A
Tracker500/500i connected to a differential receiver
will not exhibit this error.
The Tracker500/500i indicates speed over the sea
bed. A speed/log instrument indicates speed
through the water. If there is any tidal current, these
two will be different.
Speed/log instruments are often not calibrated
accurately and do not accurately show the boat's
speed.
39