Frequency counterFS752

FS74010 MHz GPS Frequency Reference The FS740 GPS Time and Frequency System provides a 10 MHz frequency reference with a long-term stability of better than 1 × 10-13. A built-in receiver tracks any of the four major GNSS constellations: GPS, GLONASS, BEIDOU, or GALILEO. The instrument can also time tag external events with respect to UTC or GPS and measure the frequency of user inputs. The instrument has DDS synthesized frequency outputs, adjustable rate (and width) pulse outputs, and an AUX output for arbitrary waveforms including an IRIG-B timecode output. The standard timebase provides 1 × 10-9 short-term frequency stability and phase noise of less than -105 dBc/Hz (10 Hz offset). An optional OCXO (ovenized crystal oscillator) timebase provides 1 × 10-11 short-term frequency stability and phase noise of less than 130 dBc/Hz (10 Hz offset). An optional rubidium timebase provides 1 × 10-12 short-term frequency stability, phase noise of less than -130 dBc/Hz (10 Hz offset), and a long-term holdover (lost GNSS signal) of better than 1 μs/day. Both optional timebases (OCXO or rubidium) provide a dramatic improvement in the holdover characteristics, a 30 dB reduction in the phase noise, and a tenfold reduction in the TDEV (rms timing deviation). There are some users who would not need this performance improvement. For example, users who only need time tags with 1 µs accuracy or frequency measurements with 1 × 10-8 accuracy could use the standard timebase.