GPS/GNSS Modules

GPS Disciplined Oscillator Model GF-8557Discontinued Products

For Timing

The GF-8557 is a high sensitivity GPS Disciplined Oscillator with internal OCXO, which provides highly-accurate and highly-stable 1PPS/10MHz.

The GF-8557 outputs 1PPS synchronized with UTC as well as 10MHz coherent to 1PPS.
The GF-8557 is designed especially for wireless broadband base stations for CDMA, WiMAX, and LTE networks and for multimedia broadcast base stations.

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  • Built-in high sensitivity GPS receiver.

  • Provides highly-stable frequency and highly-accurate UTC time anywhere around the world.

  • Outputs 1PPS (pulse per second) synchronized with UTC time.

  • Outputs 10MHz sine wave and square wave coherent to 1PPS.

  • Continuously outputs highly-accurate and highly-stable 1PPS and 10MHz clock even when only one GPS satellite signal is received.

  • Continuously outputs highly-accurate and highly-stable 1PPS and 10MHz clock even when the GPS signal is lost in holdover.

  • Maintenance-free with the OCXO controlled by GPS.

  • DGPS with SBAS satellites (WAAS/MSAS/EGNOS).



GNSS Reception CapabilityGPS L1 C/A, SBAS L1 C/A
GNSS Reception14 channels (GPS, SBAS)
Sensitivity-140dBm to -110dBm
10MHz Output (Lock State)Frequency Accuracy:< ±1×10-12
1PPS Output (Lock State)1PPS Accuracy: < ±150ns
1PPS Stability: < 30ns(1σ)
10MHz Output (Holdover)Frequency Accuracy: <±1×10-9/24h (Temperature alternation within 20°C )
1PPS Output (Holdover)1PPS Accuracy: <±8μs/24h (Temperature alternation within 20°C )
Supply Voltage5.5VDC
Power ConsumptionNormal Status < 10W, Startup < 14W
Operating Temperature-20°C to +80°C
Antenna DetectionShort and Open Detection
Alarm OutputAvailable
Outer Size100mm×100mm×19.9mm (It excludes the interface connectors.)
ProtocolNMEA 0183 , TOD




Locate a Distributor Contact a local distributor for further details.

* Specifications subject to change without notice.

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