Trimble Inc. 6248192-B1 Benutzerhandbuch

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SPSx80 Smart GPS Antenna User Guide     
31
Setup Guidelines     
4
Trimble recommends that you install lightning protection equipment at 
permanent base station locations. Equipment should include a gas capsule 
lightning protector in the GPS and radio antenna feed line and appropriate 
safety grounding. A static dissipater near the antennas can reduce the likelihood 
of a direct lightning strike. Also protect any communications and power lines at 
building entry points. For more information, contact your local Trimble dealer, 
or go to the Huber and Suhner website (www.hubersuhnerinc.com).
Trimble recommends that you use surge protection equipment on all 
permanently installed equipment.
Permanent installation antenna cabling for the SPSx50 Modular GPS 
receiver and SPS770 GPS receiver
Many permanent base station installations have unique cabling requirements. 
Depending on the available infrastructure, you may need to mount the antenna a 
considerable distance from the receiver.
The SPSx50 and SPS770 can withstand a loss of 12 dB between the GPS antenna and 
the receiver. The degree of loss in a coaxial cable depends on the frequency of the 
signal passing through it. Table 4.1 lists some common cable types and the maximum 
length you can use before an inline amplifier for GPS frequencies is required.
Rover operation guidelines
The second part of the RTK GPS system is the rover receiver.
The rover receiver is mounted on a pole, vehicle, marine vessel, or in a backpack, and is 
moved between the points that require measurement or stakeout. The rover receiver is 
connected to a base station or to a source of RTK corrections such as a Virtual 
Reference Station (VRS) system. The connection is provided by an integrated radio, a 
Table 4.1
Maximum cable lengths
Cable type
Maximum length (for use without an inline amplifier)
RG-214
30 m (100 ft)
LMR-400
70 m (230 ft)
LMR-500
85 m (280 ft)
LMR-600
106 m (350 ft)
Heliax LDF4/50
165 m (540 ft)
Heliax LDF4.5/40
225 m (740 ft)