NorthStar Navigation 978/897-6600 Marine GPS System User Manual


 
SECTION SEVEN: Troubleshooting and servicing the 958 system
Page 38 958 Installation Manual, Rev. A1
TABLE 13: Troubleshooting the 2701 and AN205-P installation
If . . . Then . . .
Satellite signals are often lost, or the
AN205-P works while youre travelling in
one direction, but not the opposite one.
The antenna may be partially shaded by metallic objects around it.
Re-position or raise the antenna away from the object for a better
satellite view.
Signals may be lost when the antenna is under a bridge or when
shielded by buildings.
Poor SNR readings are obtained even
after running the 958 for several minutes
Check the quality of the antenna locationthe antenna should have a
clear view of the sky.
Make sure the antenna is clean, and not covered with ice, snow, or
exhaust soot.
Youre having difficulty obtaining WAAS
satellites
Check that WAAS is available in your operating area.
Reset the 958s satellite elevation setting to its default (10 degrees).
Check that the 958s
DIFFERENTIAL OPERATIONS
option is set to
either
WAAS
or
AUTO
.
The following error message appears on
the 958 display:
COMM FAIL
TOO FEW SATS
With power on, check the antenna and wiring connections.
Disconnect the 2701 from the 958, then measure the 25-pin 2701
connector for 10 - 36 volts at pin 25, ground at pin 13.
Check the 2701s remote-on: Pin 12 should measure less than 5
ohms to ground.
After testing above, re-connect the cable and turn the 958 off, then
turn it back on again.
Check if anything is blocking the 2701s or antennas view of the sky.
The almanac may not be complete; allow up to 30 minutes for full
initial acquisition.