Frequency Standards

Frequency Standards

Time and Frequency Standards

Available in the UK from APC TimePendulum Instruments’ frequency standards offer extreme accuracy for applications in telecommunications, calibration laboratories, automated test systems and design departments.

GPS-disciplined references offer traceable Cesium-like stability at an attractive price. Units are self-calibrating. A stand-alone high stability frequency standard is available where traceability to external reference is not required.

APC Technology Group plc


  • GPS-disciplined Rubidium clock
  • Internal battery option for transportation and mains-free field use
  • Two switchable 1.544 MHz (T1) or 2.048 MHz (E1) front-panel outputs
  • One switchable 1 PPS or 10 MHz front-panel output
  • Eight optional frequency outputs: 1, 5 & 10 MHz
  • User friendly front panel operation, selectable for six language
  • Use of both GLONASS and GPS gives better signal coverage (GPS-12RG)

> View GPS-12R/12RG Datasheet

> View GPS-12R/HS Datasheet

APC Technology Group plc


  • GPS-controlled frequency standard
  • Choice of Rubidium or ovenized crystal oscillator
  • Traceable internal calibration system approved by Swedish National Testing and Research Institute
  • Remote monitoring via Ethernet interface
  • No doubt-about-accuracy via display of frequency offset
  • Five standard frequency outputs; 4×10 and 1×5 MHz; Five more optional outputs

> View GPS-88/89 Datasheet

APC Technology Group plc


  • Stand-alone frequency reference standard
  • Rubidium (6689) or high stability ovenized crystal oscillator (6688)
  • Distribution amplifiers for 5×10 MHz and 1×5 MHz outputs as standard
  • Optional 10×10 MHz outputs
  • 0.001 ppm aging in 10 years (Rubidium)

> View 6688/6689 Datasheet

For more information about our range of time and frequency products from Pendulum, contact APC Time on: