APX-GTS300 GNSS Rubidium Timing System
Product Overview
The APEX APX-GTS300 is a GNSS rubidium timing system: a satellite disciplined reference with an atomic oscillator at its core, built for stations that have to keep accurate time even when the satellite signal is gone for a long time.
Timing systems in power, transport and telecom sites are usually asked for two different things at once. They must produce the physical signals the installed equipment expects, and they must keep producing them when the reference is interrupted. A crystal oscillator answers the first requirement but not the second; the rubidium oscillator inside the APX-GTS300 is what carries the station through an outage measured in hours, keeping frequency stable and time traceable so protection records, event logs and transmission links stay consistent.
The system supplies a complete output set from one unit: 1PPS and TOD timing, IRIG-B and DCF77 time codes, NTP for the network, and 1, 5 and 10 MHz frequency references, with electrical interface types selected to match the devices in the station. Status, alarms and holdover state are visible locally and available to supervisory systems.
It is supplied as a rack mount unit for equipment rooms and substations, with the GNSS antenna, cable and protection available as one matched set so the whole reference chain is specified together.
Key Features
- GNSS reference with a rubidium atomic oscillator at the core
- Holdover measured in hours instead of minutes
- 1PPS accuracy better than 30 ns RMS while locked to the satellite reference
- Timing outputs including 1PPS, TOD, 1PPM and 1PPH
- Time code outputs including IRIG-B AC, IRIG-B DC and DCF77
- Frequency outputs at 1 MHz, 5 MHz and 10 MHz for transmission equipment
- NTP service for supervisory, server and management networks
- Automatic return to the satellite reference and re-discipline after an outage
- Holdover, reference and antenna fault alarms for supervisory systems
- Electrical interface types matched to the station's equipment list
- Rack mount chassis for equipment rooms, substations and stations
- Antenna, cable, splitter and surge protection available as one set, RoHS compliant
Technical Specifications
| Specification | Detail |
|---|
| Part Number | APX-GTS300 |
| Product Type | GNSS rubidium timing system |
| GNSS Reference | GPS and BeiDou timing configurations |
| Oscillator | Rubidium atomic oscillator, disciplined from GNSS |
| 1PPS Accuracy | Better than 30 ns RMS while locked |
| Holdover | Hours of traceable time at the site after a reference loss |
| Timing Outputs | 1PPS, TOD, 1PPM, 1PPH |
| Time Code Outputs | IRIG-B AC, IRIG-B DC, DCF77 |
| Frequency Outputs | 1 MHz, 5 MHz, 10 MHz |
| Network Time | NTP over Ethernet |
| Alarms | Reference, antenna and holdover status to supervisory systems |
| Output Interface Types | TTL, RS232, RS422 and optical options depending on configuration |
| Mounting | Rack mount chassis |
| Application | Power, transport and telecom stations with long outage exposure |
| Compliance | CE, RoHS |
Applications
Power Transmission and Substations
Keeps fault records and protection events on one traceable time base, which is what makes post incident analysis possible when several devices have to be compared.
Rail, Transport and Traffic Systems
Holds a stable reference for signalling, control and monitoring equipment across sites where the antenna cannot be guaranteed to stay clear.
Telecom and Broadcast Stations
Provides time codes and frequency references for transmission and broadcast equipment that must stay within limits during maintenance on the antenna system.
Deployment and Selection Notes
Select this system when the outage answer is holdover, not redundancy. If a station cannot justify a second antenna, or if the antenna is hard to reach and faults take hours to clear, the rubidium core is what keeps the timing signals inside their limits in the meantime.
Install the antenna as carefully as you would for any critical timing system: a clear view of the sky, a short low loss cable, surge protection at the entry point and a mechanically sound mounting. The atomic oscillator protects the station from a lost signal, but it does not compensate for a badly chosen antenna position that loses satellites several times a day.
Decide the output mix early. Protection engineers, transmission engineers and IT each ask for a different signal, and the order is configured against that list. We keep the configuration on file, so an identical station or a later expansion is a repeat order rather than a redesign.
Compatibility
The APX-GTS300 supplies 1PPS, TOD, IRIG-B, DCF77, 1, 5 and 10 MHz signals and NTP from one unit, so protection, transmission and IT equipment can share a single traceable reference. Send the device list with the signal each one needs, along with the outage the station must ride through, and we confirm the configuration, connector types and antenna set.
Related Products
Frequently Asked Questions
What does a rubidium oscillator add to a GNSS timing system?
It is the part that keeps frequency stable and time traceable when the satellite reference is lost. Without it, holdover is good for minutes; with it, the station keeps usable time for hours.
How long can the system stay accurate without the satellite?
That depends on the accuracy budget of the equipment being fed. Tell us the budget and the worst case outage duration and we confirm whether the rubidium configuration suits the station.
Does it replace the need for a good antenna?
No. A well installed antenna and cable remain the primary reference. The oscillator protects the station when that reference is temporarily unavailable, and the alarms tell you when that has happened.
Can the same unit feed protection and IT equipment?
Yes. The time code and frequency outputs cover protection and transmission equipment, and NTP covers servers and management systems from the same reference.
Why Choose Apex
- Rubidium holdover sized against the outage your station actually has to survive.
- Output list, connector types and antenna set confirmed before the order is released.
- Configuration recorded so repeat stations and later expansions match exactly.
- Alarms that report holdover and reference faults instead of failing silently.
- Backed by a 3 year warranty and technical support on link and sync planning.
