The Keysight / Symmetricom 58503B GPS Time & Frequency Reference Receiver is a high quality source of precision time, time interval, and frequency in a lightweight compact package. The high-performance 58503B ensures excellent accuracy and reliability— the 58503B delivers precise time and frequency virtually anywhere in the world at an affordable price. When locked to the GPS signal, the Keysight 58503B provides a 10 MHz signal with an accuracy of better than 1x10–12 using a 1 day average. A 1 pulse per second (1 PPS) signal with timing jitter of <750 ps rms is provided. Time accuracy relative to GPS of 20ns (1 Sigma, typical) can be obtained once the unit is properly installed and all systematic offsets have been compensated out. If the GPS signal is interrupted, the 58503B enters an intelligent holdover mode, which ensures frequency is maintained to better than 1x10–10 per day (phase accumulation <8.6 µsec after 24 hours).