Trimble Outdoors AgGPS 252 - Manual (Page 48)

5 Troubleshooting
4 2 AgGPS 252 Receiver User Guide
Interference
Problem Possible solution
Strong magnetic fields
Strong magnetic fields have no
effect on GPS or satellite DGPS
signals.
However, some computers and other
electric equipment radiate
electromagnetic energy that can
interfere with a GPS receiver.
If you suspect interference from a local magnetic
field, move the receiver away from, or turn off, the
suspect electronics while observing the number of
satellites being tracked on the receiver or the signal-
to-noise ratio (SNR) of the satellite. If the SNR goes
up when the electronics are turned off, there may be
interference from the local electronics.
FM 2-way radios
Transmitting FM 2-way radios can
interfere with OmniSTAR, WAAS,
and GPS signal reception. Make sure that there is at least 1 m (3 ft) between
the FM 2-way radio antenna and the receiver.
Engine noise
An unshielded ignition system can
cause enough noise to block
reception of a differential signal. Use resistor spark plug wires on the vehicle ignition
system.
An alternator can cause noise that
interferes with a differential signal. Use bypass capacitors, commonly available in
automotive stores for cleaning up interference to CB
and other radios. If the problem persists, shield
engine components with aluminum foil.
Relocate the antenna on the machine.
Determine the optimal antenna location by
watching the SNR value on the AgRemote Home
screen.
Note – Before replacing engine parts in an attempt
to solve this problem, make sure that the problem is
not caused by a computer or power source near the
receiver. Some computers and their power sources
cause noise that disrupts GPS and satellite DGPS
signals.
Ag252_100B_UserGuide_ENG.book Page 42 Thursday, July 28, 2005 4:06 PM