SRS
FS725 – Rubidium Frequency Std.
Overview
The FS725 integrates a rubidium oscillator (SRS model PRS10), a low noise universal AC power supply, and distribution amplifiers in a compact half-width 2U chassis. It provides stable and reliable performance, with an estimated 20 year aging of less than 5 × 10-9 and a demonstrated rubidium oscillator MTBF of over 200,000 hours. The FS725 is an ideal instrument for calibration and R&D laboratories, or any application requiring a precision frequency standard.
Key Features
- 10 MHz and 5 MHz outputs
- 20 year aging less than 0.005 ppm
- Ultra low phase noise
- (<-130 dBc/Hz at 10 Hz)
- Built-in distribution amplifiers
- 1 pps input and output
- RS-232 computer interface


