GPS splitters allow a feed from a single GPS/GNSS antenna to be shared between multiple receivers.
Cost savings can be achieved by reducing the amount of cabling required to install multiple receiving devices. A single antenna and surge suppressor can be installed and shared between multiple GPS NTP servers or other GNSS receivers.
A disadvantage of splitters is that they create a single point of failure. If the single antenna fails or indeed the splitter itself, the feed to all the connected receivers will be lost.
Additionally, in some instances, the cost of a splitter can out-weigh the cost of installing separate antennas for each receiver.
Splitters are generally broken down into two groups, passive and active.
Passive Splitters
Passive splitters are sometimes referred to as DC-pass splitters. Generally passive splitters do not require a separate power supply unit as they are powered from a connected GPS receiver. They pass DC current from a receiver unit connected to one of the GPS outputs to power the splitter and antenna.
A disadvantage of passive splitters is that they have associated signal losses on each output port – sometimes as much as 6dB. The signal loss has the effect of reducing the overall cable length that can be used between an antenna and receiver.
Active Splitters
Active splitters are sometimes referred to as DC-blocked splitters.
Active splitters have a PSU to power the splitter and GPS antenna. They do not take any power from connected receivers. However, care must be taken to ensure that the correct voltage is supplied to the connected antenna.
Active splitters often provide some signal amplification to overcome the losses associated with splitting the input signal. The amplification has the effect of not requiring the overall cable length between an antenna and receiver to be reduced.
Smart Power Splitters
Some passive splitters have the ability to automatically switch which output is used to power the antenna, if the powering receiver is disconnected from the splitter. These are often referred to as Smart Power Splitters.
GNSS Signal Reception
GPS and Galileo Global Navigation Satellite System (GNSS) signals are transmitted at an identical frequency. Therefore, most GPS/GNSS splitters can receive both GPS and Galileo signals.
Antenna Emulation
Many splitters have (200Ω) resistors on each output to a GNSS receiver to simulate antenna current draw. The current draw prevents antenna alarm faults on receivers that have antenna detection circuitry.
Using GNSS Splitters With TimeTools NTP Servers
Passive splitters can be used with all TimeTools NTP server models. However, they may reduce the antenna cable length that can be installed, due to signal losses introduced by the splitter.
Smart Power Splitters often have a high switchover voltage threshold. The TA-Series antenna output voltage is 3.3V which may not be high enough for Smart Power Splitters. Smart power splitters are not recommenced for use with TimeTools TA-Series NTP servers.
Active splitters are powered from a power supply unit, they do not take power from any connected receiver. Active splitters can be used with all TimeTools NTP server models.
TA-Series NTP Server models do not require splitter antenna emulation. While older T-Series models do.
TW3040 and TW3740 Antennas
TimeTools TW3040 and TW3740 antennas have a wide voltage input range of 2.5 to 12 VDC @ 19mA. A splitter must supply power to the antenna within this voltage range.
Additionally, if a GPS amplifier is used to extend cable distance, it also needs to be powered by the splitter. TimeTools T-AD200-8 amplifier has an input voltage range of 5 to 20VDC @ 15mA max.
GPS Splitter Manufacturers
The following links are to manufacturers of GPS splitters:
https://amlant.co.uk/ad325-splitter/
https://www.etlsystems.com/catalogue/rf-components/gps-and-gnss/gps-splitters
https://www.gpssource.com/collections/gps-splitter
Disclaimer
The links on this page are provided for your information and convenience only and are not an endorsement by TimeTools of the content of such linked websites or third party products or services.
TimeTools therefore makes no warranties or representations, express or implied about such linked websites, the third parties they are owned and operated by, the information contained on them or the suitability of quality of their products or services.
Accurately synchronise the time on computers and network infrastructure in your organization with TimeTools TA310 GPS Network Time Server. The TA310 is designed and manufactured in the UK, and provides:
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