Time and Frequency Standards
Available in the UK from APC Time, Pendulum 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.

GPS-12R/12RG
- 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)

GPS-88/89
- 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

6688/6689
- 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)