User's Manual

SPSx50 Modular GPS Receiver User Guide 33
Setup Guidelines 4
Base station setup guidelines
For good performance, observe the following base station setup guidelines:
• Place the GPS receiver in a location on the jobsite where equal range in all
directions provides full coverage of the site. This is more important on larger
jobsites, where the broadcast range of the base station radio may limit the
operations of the GPS system.
• Place the GPS antenna in a location that has a clear line of sight to the sky in all
directions. Do not place the GPS antenna near vertical obstructions such as
buildings, deep cuttings, site vehicles, towers, or tree canopy.
• Place the radio antenna as high as practical. This minimizes multipath from the
surrounding area, and enables the radio to broadcast to the maximum distance.
Note – The radio antenna must have a clear line of sight to the sky at all times during
operation.
• Choose the most appropriate radio antenna for the size and footprint of the site.
The higher the gain on the antenna, the longer the range. If there is more focus
on the transmission signal, there is a reduced coverage area. A 3 db or 5 db gain
antenna provides a mix of good range and reasonable directional coverage.
• Make sure that the GPS receiver does not lose power. The GPS receiver has an
integrated battery, which has to be charged. To operate for the full day without
loss of power at the base station, provide external power. Sources of external
power include:
–AC power
– 12 V car or truck battery
– Trimble custom external battery pack
– Generator power
–Solar panel
When you use an external power supply, the integrated battery provides a
backup power supply, enabling you to maintain continuous operation through
power outages. When the GPS receiver is connected to a power source greater
than 15 V, the integrated battery is continuously charged from the connected
power source. This helps to ensure that the battery stays charged.
• Do not locate a GPS receiver, GPS antenna, or radio antenna within 400 meters
(about 1312 feet) of:
– a powerful radar, television, or cellular communications tower
–another transmitter
– another GPS antenna