Meinberg IMS-GPS180, Руководство пользователя

Страница: 28 / 31

4 GPS Clock
4.2 Meinberg GPS Antenna/Converter
4.2.1 Introduction
The Meinberg GPS antenna/converter unit combines a standard GPS patch antenna with a frequency converter
which translates the original 1.5 GHz signal received from the GPS satellites to an intermediate frequency, so
a standard coaxial cable type like RG58 can be used for antenna cable lengths up to 300 meters (1000 ft). If
a low-loss cable type like RG213 is used then even 700 meters (2300 ft) between receiver and antenna are
possible without requirement for an additional amplifier.
Surge protectors are optionally available and should be used in the antenna line to protect the receiver from
high voltages spikes e.g. due to lightning strikes close to the antenna. The antenna/converter unit is remotely
powered by the connected GPS receiver via the antenna cable, so no external power supply is required near
the location of the antenna if a coaxial cable is used.
If more than a single GPS receiver are to be operated then a GPS antenna splitter can be used to distribute
the GPS signal from a single antenna. The GPS antenna splitter provides 4 outputs and can be cascaded to
supply even more than 4 receivers with the GPS signal.
Alternatively there is also a GPS Optical Antenna Link (GOAL) available which uses a fiber optic connection
between the antenna and the receiver which allows for a length up to 2000 meters (6500 ft), and provides a
high level of insulation and surge protection due to the optical transmission. Since the fiber optic connection is
unable to provide the antenna with DC current, an extra power supply is required in this case at the location
of the antenna.
Due to the specific requirements for remote powering and frequency conversion the Meinberg GPS equipment
is not necessarily compatible with GPS equipment from 3rd party manufacturers.
IMS-GPS180 Setup Guide Date: 10th January 2018 25