SRS Stanford Research Systems Model FS725 Rubidium Frequency
Standard 0 MHz and 5 MHz outputs
Description of SRS Stanford Research Systems FS725 Rubidium Frequency Standard 0 MHz and 5 MHz outputs
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.
There are two 10 MHz and one 5 MHz outputs with exceptionally low
phase noise of (-130 dBc/Hz at 10 Hz offset) and one second Allan Variance of (<2 × 10-11) . The FS725 can be phase-locked to an external 1 pps reference
(like GPS) providing Stratum 1 performance. A 1 pps output is also
provided that has less than 1 ns of jitter, and may be set with 1
ns resolution.
Up to three internal distribution modules can be added to the
FS725. Each module has four 10 MHz outputs, one 5 MHz output, and
one 1 pps output, all with the same low phase noise, harmonic
distortion and jitter.
An RS-232 interface allows direct communication with the rubidium
oscillator. Using the provided Windows software, you can easily
monitor and control 1 pps timing, and determine the instrument's
operational status.
There are two alarm relays that indicate the status of the rubidium
oscillator lock state and synchronization to an external 1 pps
input. The relays are SPDT, providing both normally-open and normally-closed contacts .
Key Features of SRS Stanford Research Systems FS725 Rubidium Frequency Standard
20 year aging less than 0.005 ppm
10 MHz and 5 MHz outputs
1 pps input and output
Built-in distribution amplifiers
Ultra low phase noise
(<-130 dBc/Hz at 10 Hz)
Specification of FS725
| Output | Front-Panel Indicators | |
| Output frequencies | 10 MHz sine, 5 MHz sine, 1 pps pulse (10 µs wide) | Power | "On" when AC power is applied |
| Amplitude | 0.5 Vrms, ±10 % | Locked | "On" when frequency is locked to rubidium |
| 1 pps pulse amplitude | 2.5 V into 50 Ω, | 1 pps input | Blinks with each 1pps reference input applied to rear panel |
| 5 V into high-impedance loads | 1 pps sync | "On" when 1pps output is synchronized within ±1 µs of 1pps input |
| Phase noise (SSB) | <-130 dBc/Hz (10 Hz) | Receive | Blinks when RS-232 characters are received by FS725 |
| <-140 dBc/Hz (100 Hz) | Send | Blinks when RS-232 characters are sent by FS725 |
| <-150 dBc/Hz (1 kHz) | | |
| <-155 dBc/Hz (10 kHz) | Environmental |
| Spurious | <-100 dBc (100 kHz BW) | Operating temperature | +10 °C to +40 °C |
| Harmonics | <-40 dBc | Temperature stability | Δf/f < ±1 × 10-10 (+10 °C to +40 °C) |
| Accuracy at shipment | ±5 × 10-11 | Storage temperature | -55 °C to +85 °C |
| Aging (after 30 days) | Magnetic field | Δf/f < 2 × 10-10 for 1 Gauss field reversal |
| Monthly | <5 × 10-11 | Relative humidity | 95 % (non-condensing) |
| <2.5 × 10-11 (at shipment) with opt. C | General |
| Yearly | <5 × 10-10 | AC power | 90 to 132 VAC or 175 to 264 VAC, 47 to 63 Hz, 50 W |
| 20 years (typ.) | 5 × 10-9 | Dimensions | 8.5" × 3.5" × 13" (WHL) |
| Short term stability | <2 × 10-11 (1 s) | Weight | 9 lbs. |
| (Allan variance) | <1 × 10-11 (10 s) | Warranty | One year parts and labor on defects in materials and workmanship |
| <2 × 10-12 (100 s) | | |
| Holdover | 72 hour Stratum 1 level (1 × 10-11) | | |
| Frequency retrace | ±5 × 10-11 (72 hrs. off, then 72 hrs. on) | | |
| Settability | <5 × 10-12 | | |
| Trim range | ±2 × 10-9 (0 to 5 VDC) | | |
| ±0.5 ppm (via RS-232) | | |
| Warm-up time | <6 minutes (time to lock) | | |
| <7 minutes (time to 1 × 10-9) | | |
Ordering Information for FS725
FS725 Benchtop Rb frequency standard
Option 01 Distribution amplifier (6 outputs)
Option 02 Distribution amplifier (12 outputs)
Option 03 Distribution amplifier (18 outputs)
O725RMD Double rack mount kit
O725RMS Single rack mount kit
FAQ:
1.Can you ship order to Canada or Australia?
Yes,we can .We send orders worldwide.
2. What delivery method do you use? and delivery time?
We can ship by EMS,DHL,FedEx,UPS,TNT with tracking number. Usual
delivery time is 4-7 workdays.
3. What is your payment term?
100% T/T payment before shipment.
4. How can I ask any other question?
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