Siemens RUGGEDCOM RX1400 Installation Manual

Also see for RUGGEDCOM RX1400: Reference guide Installation guide Installation guide

Installing the Device2.5.4 Connecting a GPS AntennaNOTICEA site survey is recommended prior to any installation to help determine the best lo-cation for the GPS antenna. For assistance, contact a Siemens Sales representative.NOTICEAlthough it is impossible to protect the antenna from a direct lightning strike, theantenna and connected components can be protected from secondary effectsthrough site selection and by installing protection devices.Install the antenna at least 15 m (49 ft) away from and lower than any structuresthat attract lightning. GPS antenna damage is usually not the result of a direct light-ning strike, but due to high currents induced by the effects of a lightning strike ona nearby structure. Lightning arrestors should also be installed in the antenna lineto protect the receiver and connected devices. If a lightning arrestor is installed, it isimportant to make sure it has a low impedance path to ground.To promote signal reception and avoid signal saturation at the receiver input, theoverall GPS system requires a relative gain between 5 and 18 dBi.Use only low loss, 50 Ω coaxial cabling when connecting the GPS and any other op-tional components to the RUGGEDCOM RX1400.NoteUsing any length of coaxial cable will add some time delay to the GPS signal, whichdegrades the accuracy of the calculated time and position. The time delay is depen-dent on the type of dielectric material in the cable and ranges from 1 to 2 ns/ft. Thetable below gives some examples of the delay that can be expected based on the di-electric type.Dielectric Type Time Delay (ns/ft) Propagation Velocity (% of c)Solid Polyethylene (PE) 1.54 65.9Foam Polyethylene (FE) 1.27 80.0Foam Polystyrene (FS) 1.12 91.0Air Space Polyethylene (ASP) 1.15 to 1.21 84 to 88Solid Teflon (ST) 1.46 69.4Air Space Teflon (AST) 1.13 to 1.20 85 to 90To connect a GPS antenna, do the following:1. Mount the antenna to a pole or wall in an area that provides good signal cover-age and is away from any signal noise emanating from other communicationsequipment. Make sure 90° of the sky is visible to the antenna.RUGGEDCOM RX1400Installation Manual, 09/2019, C79000-G8976-1103-13 19