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SR Series GPS \ LF Radio NTP Time Servers

Synchronize your network with microsecond precision using Network Time Protocol (NTP \ SNTP).

Accurately synchronize Windows, Linux, Unix, Servers and Workstations, Time Displays, CCTV systems, DVR’s, telephone systems, switches, routers and more!

GPS, MSF and DCF-77 reference clock options for Stratum 1 operation. Peering and Stratum 2 operation via NTP servers.


PLEASE NOTE: TimeTools SR Series has now been superseded by the T300 GPS NTP Server Appliance and T550 GPS/GLONASS/BeiDou/Galileo NTP Server.


TimeTools SR Series GPS \ DCF-77 \ MSF NTP Network Time Server

Key Features

  • Competitively Priced, True Stratum 1 NTP Time Servers
  • Single and Dual Independent LAN options
  • GPS, Radio and Dual Reference Clock Options
  • High Stability TCXO Options for Extended Holdover

Key Benefits

  • Accurately Synchronize Windows, Linux and UNIX Clients
  • Accurate, Reliable, Source of Time Inside Your Firewall
  • Serves Thousands of Network Time Clients
  • Accurately Synchronize Time Critical Processes


TimeTools SR Series provides a complete range of Linux-based, true Stratum-1, NTP Network Time Servers that represent a real breakthrough in price and performance.

Housed in a rugged, yet compact, 1U high, rack-mountable enclosure, the SR series takes up minimal valuable rack-space.

By utilising a customized Linux kernel and an unmodified version of the latest network time protocol distribution, NTP version 4.2, the SR series offers true NTP / SNTP functionality.

GPS, Radio and Dual Reference Clock Options

Multiple external reference clock combinations can be provided with the SR series; GPS, MSF radio, DCF-77 radio and dual GPS / radio reference capabilities. The SR series provides true flexibility.

The SR series is also provided with a cutting-edge high-sensitivity GPS receiver that can often operate with an indoor located GPS antenna. Additionally, the new receivers can operate from a single satellite-in-view making operation from a window often possible. These features potentially provide a great saving on installation costs when compared to traditional roof-mounted GPS antennas.

Of course, our GPS antennas are completely weatherproof and can be roof-mounted outdoors, if required.


High Stability Extended Holdover Option
High-stability GPS/LF disciplined Temperature Controlled Crystal Oscillator (TCXO) options are available to maintain accurate time for extended periods in the event of GPS / radio reference clock signal loss.

Secure Configuration and Maintenance
A secure (HTTPS), easy to use, password-protected user interface is provided for system configuration and management. FTP/SCP can be utilised to download NTP statistics and upload firmware upgrades, available from TimeTools free of charge.

5-Year Warranty
The SR Series NTP Server is a low-power convection cooled device with no moving parts, aiding long-term reliability. Our confidence in the reliability of the device is reflected in the provision of an industry leading 5-year warranty.

Customer Testimonials
Just installed our first SR9210. We were quite surprised about the craftsmanship and quality of the product. The software seems to be engineered very well too. We were able to complete the set-up within a time frame of one hour from first power on to full configuration – and we wrote the documentation for our configuration in parallel. We are using GPS, DCF-77 and three pools for fail-over reasons. Did some fail-over tests too – everything worked as expected. If anyone asks me for advice on a ntp time server, my answer will be: go to TimeTools and place your order. Thank You very much.
Matthias Petz, ICT Systems Engineer and Project Manager
Strüby Konzept AG, Sweden

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SR7110 – Entry Level, Competitive Price
The SR7110 is an entry-level Linux-based true NTP time server at a highly competitive price. It can utilise GPS or LF radio time references to provide stratum-1 NTP functionality, ideal for synchronizing digital clocks, DVR’s and smaller networks.

SR9210 – Feature Rich, Value
The mid-range SR9210 provides a high specification NTP network time reference. It incorporates a high-throughput Ethernet network interface, combined with the ability to accept GPS, LF radio or dual GPS / LF radio external time references. The SR9210 is an ideal time reference where a large number of network time clients are to be synchronized accurately and reliably.

SR9750 – High Stability, Extended Holdover
The SR9750 provides all the features of the SR9210 with the additional benefit of a high-stability disciplined TCXO oscillator for extended holdover in the event of primary reference loss. Ideal where a highly reliable source of time is required.

SR9860D – Dual LAN, High Accuracy
The top-of-range SR9860D incorporates dual independent LAN capability for synchronizing multiple networks. It also provides enhanced precision along with a GPS/LF disciplined TCXO for extended holdover. Ideal for reliably synchronizing multiple, large, networks with a high degree of accuracy.

Model Comparison Chart

   LAN 10/100 Mbit BaseT , RJ45 auto-sensing
Timing Protocols
   NTP v2, v3, v4, SNTP v3, v4
   NTP Peering
   NTP Broadcast
   NTP MD5 Authentication
   NTP Requests / Second (typical)
> 200
> 1000
> 1000
   Maximum Number of NTP Clients (typical)
> 64,000
> 64,000
   NMEA RS232 Output
Time Reference Options
   12 Channel GPS Receiver High Sensitivity
Indoor, Over- Determined Clock,
Single Satellite Operation
   LF – MSF (UK) Reference Clock
   LF – DCF-77 (German) Reference Clock
   Dual GPS and LF Radio Reference Clocks
Monitoring and Reporting
   SNMP v1 / v2c Trap Alarms
(Can be disabled)
   System Logging (SysLog)
   Remote System Logging (Remote Syslog)
   GPS Satellites in View &
Signal to Noise Ratio (SNR)
Configuration Protocols
   HTTP (Web) / HTTPS
(SSL Secure Sockets Layer)
   SSH (Secure Shell), SCP
(Secure Copy Protocol)
   Console (RS232)
Oscillator Options
   Standard Crystal Oscillator
   High Stability GPS\LF Disciplined
TCXO Oscillator
Timing (Typical)
   GPS Accuracy
1 ms
60 ns
60 ns
 60 ns
   LF Accuracy
10-50 ms
1-20 ms
1-20 ms
 1-20 ms
   NTP Accuracy (typical, GPS Synchronized)
<10 ms
< 250 us
< 250 us
 <1 us
   24 Hour Holdover (GPS disciplined, typical @ 25C)
<±10 ms
   Buffered 1 PPS Output on BNC

Mechanical\Environmental Specification

Dimensions 483 x 205 x 44 mm (19.0″ x 8.05″ x 1.73″)
Construction 1U High 19″ Rack mount, 1.8mm Aluminium
Weight approx 2.2Kg (4.84lbs)
Power Supply Universal 100-250 VAC 50- Hz CE/UL/CSA Approved PSU
(Optional 9-36V DC IN and 85-250V DC IN versions available)
Power Consumption approx 5W
0C ~ +50C (Extended temperature range options available)
Storage Temperature -10C ~ +60C (Extended temperature range options available)
Relative Humidity 95% non-condensing
Approvals CE, EN61000-6-1, EN61000-6-3

Input\Output Specification

LAN 10/100 Mbit BaseT , RJ45 auto-sensing
Serial Console 9 way ‘D’ RS232, 9600, N, 8, 1
GPS Input TNC female
LF/AUX Input: 9 way ‘D’
Power Double Fused IEC Inlet
PPS (optional) Buffered pulse per second output on BNC (optional)

Integral GPS Receiver Specification

Type True GPS Timing Receiver, 12 Channel, L1 1575.42 MHz
Features High sensitivity, Over-determined clock modes, Single satellite in view
Timing GPS Time Traceable to UTC (USNO)
Accuracy +/- 60 nsec UTC (typical)
(Cold Start)
38 sec

SR Series NTP Time Servers Product Codes

SR 7110 GPS \ LF NTP Server SR7110-20P
SR 9210 GPS \ LF \ Dual Reference NTP Server SR9210-20P
SR 9750 GPS \ LF \ Dual Reference NTP Server with TCXO SR9750-20P
SR 9860D GPS \ LF \ Dual Reference NTP Server with TCXO SR9860D-20P
Scope of Supply: SR Series NTP Time Server, IEC Mains Lead,
Console Configuration Cable, Product User Guide and NTP Client CD.

(Optional 9-36VDC IN, 85-250VDC IN and extended temperature range versions available.)

Optional SR Series GPS Reference Clock Antennas and Accessories

Jam-Resistant Pole Mounting GPS Antenna and Mount T-3072
30m RG58 Cable TCX-030
50m LMR195 Cable TCX-050
100m LMR400 Cable TCX-100
Additional cable lengths available on request
GPS Surge Suppressor SPP-GPS
GPS Amplifier – 20db T-AD200-8
LF / GPS over optical fibre systems P.O.A
GPS Splitters – 2 to 32 way, compact or rack-mount P.O.A

Optional SR Series LF (Radio) Reference Clock Antennas

Ultra-High-Gain MSF (UK) Antenna SR-MXS-00
Ultra-High-Gain DCF-77 (German) Antenna SR-DXS-00
LF Radio Surge Suppressor LF-SPP


How To Buy

TimeTools sells directly to you!

Typically, our products are available from stock and can be dispatched to locations world-wide.

You can purchase any of our products by contacting us directly for a quotation, advice or to set up an account.

Additionally, we accept most credit cards, including Visa and MasterCard.

Request A Quote

Alternatively, please contact one of our approved representatives in your region.

About Us

TimeTools is a leading manufacturer of precise time references for synchronizing servers, workstations and computer network infrastructure. For well over a decade, TimeTools has been providing timing solutions to high-profile companies world-wide. Here is a small selection of companies who trust TimeTools for their timing requirements:

TimeTools Customers
TimeTools Customers

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Quality: ISO9001

TimeTools is an ISO9001:2008 accredited company. ISO9001 accreditation demonstrates that quality assurance and customer satisfaction is of paramount importance to us.

TimeTools is an ISO9001:2008 Registered Company

We are also a member of the CE Marking Association, which enables us to meet our legal obligations with regards to the CE Mark and product conformity, and with keeping up-to-date with changes in legislation.

CE Marking Association Logo
CE Marking Association Logo