Quartzlock Products


The Quartzlock E8000-TT GPS Frequency and Time Transfer Reference is a breakthrough in exceptionally low cost, traceable, 1-U rack mount,  calibration-free, off-air frequency & time standards. These very low cost references maintain the high frequency & time accuracy required for demanding applications.

The E8000-TT uses a commercial GPS timing receiver. This performs a self survey when moved to a new location, and stores the averaged position. The stored position is used when the unit is reset, and remains valid provided the unit is not moved.

With a valid stored position, the GPS receiver switches into over determined clock mode, and uses all satellites in view to provide the best possible estimate of GPS time, output as the rising edge of a pulse every second (1PPS).

The 1PPS output from the GPS receiver is phase modulated with a saw tooth with a peak amplitude of about 12ns. This is due to the finite clock resolution used in the GPS receiver.

The E8000-TT uses a Kalman filter to a) correct the local clock, which is an OCXO, and b) to smooth the 1PPS and remove the saw tooth modulation. The eventual 1PPS output from the E8000-TT has short term phase jitter of less than 1ns RMS.

When using short or medium baseline time transfer, both receivers will largely share the same constellation, and will therefore see the same offset from UTC.

The 1PPS output from the E8000-TT receiver can be offset by up to ±500ms in 1ns steps.


  • Low distortion 10MHz sine & 1PPS outputs
  • 1x10-12 accuracy
  • No drift
  • High stability nationally & internationally
  • 1 year warranty
  • Lowest cost available
  • Very long production life & support.
  • Low noise options: -115dBc/Hz @ 1 Hz offset and -169dBc/Hz. @ 100 kHz


  • No calibration required
  • Traceable reference


  • Calibration of counters, frequency meters, spectrum & network analysers, synthesizers, & communication analysers
  • Reference for VHF, UHF & PMR TX, CDMA, Tetra, DTV & DAB
  • Production test frequency standard
  • Network time protocol use in financial, utilities, security & communications timing
  • OEM
  • Standard for calibration labs, radio workshops, labs and stations


Quartzlock’s hydrogen maser based laboratory is used in production test & quality assurance to ensure compliance with offset and stability specifications.

Standard Specification:
Output Frequency 10 MHz
Output Level +10 dBm +/-2 dBm into 50 Ohms
1 PPS Output 1
Number of Outputs 1 (up to 12 Outputs available)
STS1s 8x10-13
STS10s 4x10-13
STS100s 5x10-12
STS1000s 2x10-12
Phase Noise 1Hz -110 dBc/Hz
Phase Noise 10Hz -136 dBc/Hz
Phase Noise 100Hz -145 dBc/Hz
Phase Noise 1Kz -155 dBc/Hz
Phase Noise 10Kz -156 dBc/Hz
Harmonics dBc < -30 dBc
Spurious dBc < -80 dBc
Warm Time < 30 min
Retrace 3x10-11
PSU Nominal 230 V ac
PSU Min 90 V ac
PSU Max 240 V ac
Current 250 mA
Supply AC (DC option - allows UPS operation)
OT Min -20 C
OT Max +50 C
ST Min -55 C
ST Max +85 C

Optional Extras

Below you can choose from a range of optional extras to ensure the closest match to your requirements.

Option 47 - Add High Gain GPS Antenna & Standard PSU

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