GNSSDO goes beyond Atomic oscillators.To the next generation. OCXO equipped Multi-GNSS Disciplined Oscillator GF-8705

OCXO equipped Multi-GNSS Disciplined Oscillator ModelGF-8705

GF-8705 provides highly precise timing information (1PPS and 10MHz), which can be used as a source of IEEE1588 PTP (Precision Time Protocol)


  • Telecommunications industry/5G

  • Broadcasting industry/Digital TV

  • Finance industry/e-commerce

  • Utilities industry /smart grid

FURUNO GF-8705 is the latest timing addition to our current and extensive timing industry product line.

FURUNO continues to solidify its reputation in the timing market as a leading supplier of GNSS Disciplined oscillators. The FURUNO GF-8705 provides the highest precision and stability required to control TCXO, OCXO and Rubidium oscillators. Timing information generated by our GF-8705 is the same precision as an atomic oscillator. The GF-8705 holdover function continues to provide precise timing information even if GNSS signals are lost.

Superior timing performance

Outputs highly accurate, stable frequency and time pulse synchronized with UTC time.
Achieves the world's best-in-class holdover performance*

* Holdover performance… Timing performance continues if GNSS signals are lost.

1PPS Accuracy Holdover time
Lock State ±50 ns
Holdover ±1.5μs 24 H

Industry required holdover performance is higher than ever for supporting new LTE, 5G and other advanced infrastructure equipment. GF-8705 technology keeps the established standard 1PPS accuracy at <±1.5μs/24H during holdover.

Multi-GNSS Disciplined Oscillator
Features of GF-8705

GF-8705 is an OCXO equipped high sensitivity multi-GNSS Disciplined Oscillator. It has expanded capabilities and the world's best-in-class holdover function with low phase noise
Outputs highly stable 10MHz frequency (selectable 4-40MHz) and 1PPS or 2PPS synchronized with UTC time

  • Concurrent reception of GPS, GLONASS, SBAS and QZSS
  • Outputs highly accurate frequency and time pulse even with only one received GNSS satellite (Position-hold mode)
  • Improved Noise Tolerance (Active Anti-Jamming, Advanced Multipath Mitigation)
  • Synchronizing with external time pulse such as IEEE1588 or SyncE
  • Wide operation temperature range (-40°C to +85°C)

Click here for the detailed specifications.

Performance data

1PPS Accuracy

The following graphs display the GF-8705 1PPS time accuracy test results (10 test samples) both in Lock State (stable condition) and in holdover. The ambient air temperature was varied during the test. The GF-8705 outputs highly accurate 1PPS in Lock State, severe environments, and also in a holdover condition. The GF-8705 achieves extraordinary 1PPS performance accuracy, achieving <±1.5μs/24H in holdover thanks to our advanced FURUNO oscillator control technology. This technology controls the OCXO frequency variances, temperature, aging and other characteristics using our own proprietary algorithm.

  • Lock State

  • Holdover

TDEV(Time Deviation), MTIE(Maximum Time Interval Error)

The following graphs display the GF-8705 test results of TDEV and MTIE (Green line). The dotted line represents the specified value in ITU-T G.8272/Y.1367 “Timing characteristics of primary reference clocks *”.

* Primary reference time clocks (PRTC) provides the signals of synchronization standard for the master clock Example: Grand master clock utilized for network synchronization in a packet network.

  • TDEV

  • MITE


Multi-GNSS Disciplined Oscillator

FURUNO Advanced Multi-GNSS Disciplined Oscillator supports concurrent reception of GPS, GLONASS, QZSS and SBAS. A variety of product line up is available depending on holdover performance, low phase noise performance of reference frequency, size and cost. FURUNO Advanced GNSSDO supports Active Anti-Jamming functions and Multipath Mitigation functions and provides highly accurate and stable 1PPS synchronized with UTC time as well as highly stable frequency coherent to 1PPS.

* GF-8701 / GF-8702 and GF-8703 series are pin compatible. Also the GF-8704 is pin compatible with the GF-8705. All units have identical output protocol formats. This allows easy, multipurpose PCB development for each GF-87 series based on the particular application.


Regarding the installation environment and temperature requirements, please refer to the corresponding hardware specifications for the related device.

10MHz specifications

GF-8701 GF-8702 GF-8703 GF-8704 GF-8705
Lock State Frequency Accuracy (24H) < ±1×10-11 < ±1×10-12
Short Term Stability* < 1×10-9 < 2×10-10 < 1×10-10
Short Term Stability* - < 2×10-10 < 1×10-10

* Root Allan variance (τ=1s)

1PPS specifications

GF-8701 GF-8702 GF-8703 GF-8704 GF-8705
Lock State 1PPS Accuracy < ±100ns < ±50ns
1PPS Stability < ±15ns(1σ)
1PPS Accuracy - < ±50μs < ±10μs < ±5μs < ±1.5μs

[Test data]
1PPS Timing Accuracy <± Xμs continued from start of holdover.    * Reference information only, values not guaranteed.

GF-8702 GF-8703 GF-8704 GF-8705
1PPS Accuracy < ±0.1μs - - - 2H
< ±0.4μs - 1H 2H 6H
< ±1.1μs 1H 3H 6H 18H
< ±1.5μs 2H 4H 8H 24H(Specification)
< ±5μs 8H 16H 24H(Specification) -
< ±10μs 16H 24H(Specification) - -

Evaluation kits

Evaluation kit for GF-87 series (GF-8701, GF-8702, GF-8703, GF-8704, GF-8705).
Connect the PC with a USB port to communicate. Output time pulse (1 PPS) and 10 MHz reference frequency (selectable) from a SMA terminal.

Contents: GNSS antenna, CD (GNSS Conductor GF), USB cable

  • P/N VF-01: For GF-8701
    P/N VF-02: For GF-8702
    P/N VF-03: For GF-8703

  • P/N VF-04: For GF-8704
    P/N VF-05: For GF-8705

Monitoring Software
(GNSS Conductor GF)

  • Displays status of GNSS satellite reception.
  • Provides a simple and easy to use interface to input commands to GF-87 receivers and to store GF-87 receiver operation log files.
  • OS version: Windows 7(32bit, 64bit) / 8.1(64bit) / 10(64bit)

(Documents, Software)

You can download various documents and software for the GF-87 series.

  • Hardware Specifications
  • Protocol Specifications
  • User's Guide
  • Monitoring Software


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Inquiries about evaluation kit and products

For further information, please feel free to contact us.