User's Manual

4 Setup Guidelines
36 SPSx80 and SPSx81 Smart GPS Antennas User Guide
Figure 4.1 Rod mount for a modular GPS receiver
To mount the modular GPS receiver on a marine vessel, use the receiver bracket
(P/N 56830-00). For marine moving base and heading applications, use the
receiver bracket to mount two receivers together.
• Make sure that the rover receiver does not lose power. An SPSx50 or SPSx51 is
typically powered by its internal battery. You cannot change the battery, but the
charge typically lasts for longer than a working day. The batteries in the SPSx80
or SPSx81 can be changed when flat. (See
Chapter 3, Batteries and Power
). If you
do not use the rover receiver very often, ensure that it is charged at least every
three months. For vehicle operation or marine vessel operation, Trimble
recommends that you use an external power source so that the internal battery
can be saved for times when the receiver is being used off the vehicle or vessel.
• Do not locate the receiver or antenna within 400 meters (about 1,300 ft) of
powerful radar, television, cellular communications tower, or other transmitters
or GPS antennas. Low-power transmitters, such as those in cellular phones and
two-way radios, normally do not interfere with receiver operations. Cellular
towers can interfere with the radio and can interfere with GPS signals entering
the receiver. This does not harm the receiver, but it can prevent the receiver
electronics from functioning correctly.
• Do not use the rover receiver directly beneath or close to overhead power lines
or electrical generation facilities. The electromagnetic fields associated with
these utilities can interfere with GPS receiver operation. Other sources of
electromagnetic interference include: