Search
Home > Products > Test & Measurement Instruments > SR625

Frequency Counter SR625 ... from $6950
SR625 Frequency counter w/ Rb timebase
(Click to enlarge)
SR625 Frequency Counter
  • Rubidium atomic timebase
  • 2 GHz prescaler input
  • 11-digit frequency resolution (1 s)
  • 10 MHz Rb timebase output
  • Statistical analysis & Allan variance
  • GPIB and RS-232 interfaces
The SR625 Frequency Counter is a NIST traceable frequency counting standard for calibrating base stations, transmitters and many other types of communication systems. It combines the high resolution and wide variety of features found in the counter with the atomic accuracy of a rubidium timebase.
   Related Products

> SR620 Frequency Counter
> FS725 Rb Frequency Standard
> CG635 RF Clock Generator
> SG380 RF Signal Generator
Downloads

Datasheet
User's Manual
Prices

SR625 Frequency Counter with Rb Timebase

The SR625 Frequency Counter is a NIST traceable frequency counting standard for calibrating base stations, transmitters and many other types of communication systems. It combines the high resolution and wide variety of features found in the SR620 counter with the atomic accuracy of a rubidium timebase.

Low Drift, High Accuracy

The SR625 Frequency Counter consists of a frequency counter (SR620), a high-accuracy rubidium timebase (PRS10), and a 2 GHz input prescaler. The combination of the SR620 and the prescaler allows direct frequency measurements up to 2 GHz with twelve digits of resolution in a 100 s measurement.

The rubidium timebase ensures excellent short-term stability (<2 × 10-11 Allan variance (1 s)) and long-term drift (<5 × 10-11/month).

Simple, Portable Operation

The SR625's warmup time is less than ten minutes making it ideal for field applications. An additional back-panel output provides a rubidium stabilized 10 MHz signal which can be used to drive other test equipment (e.g., synthesizers or spectrum analyzers). The standard GPIB and RS-232 interfaces allow for complete control and data acquisition from any laboratory computer. The SR625's performance makes it the standard for remote applications or laboratory calibration.

 

 

 

 

 

Phone: (408)744-9040 • Fax: (408)744-9049 • email: info@thinkSRS.comwww.thinkSRS.com

SR625 Frequency Counter with Rb Timebase
 
The following specifications relate to the 2.2 GHz prescaler and the rubidium timebase of the SR625. Please see the section on the SR620 for general specifications relating to the counter.
Rubidium Timebase
Frequency 10 MHz
Accuracy at shipment ±5 × 10-11
One day stability 4 × 10-11/day
Long term drift <5 × 10-11/month, <5 × 10-10/year
Short term stability
     1 s Allan variance <2 × 10-11
     10 s Allan variance <1 × 10-11
     100 s Allan variance <2 × 10-12
Warmup interval 10 minutes to meet short-term stability specification
Power consumption 70 W (at warmup), 100/120/208/240 VAC, 50/60 Hz
Output 10 MHz, 1 Vpp sine wave
Prescaler
Frequency ratio 10:1
Input impedance 50 Ω
Max. input level +23 dBm
Input freq. range 50 MHz to 2.2 GHz
Input sensitivity See graph in Features section
Output
     Output load 50 Ω
     Output amplitude 700 mVpp square wave
     Output offset 500 mV
General
Size 17" × 3" × 14.5" (WHL)
Weight 15 lbs.
Warranty One year parts and labor on defects in materials and workmanship
 
 
 
 
 
 
Phone: (408)744-9040 • Fax: (408)744-9049 • email: info@thinkSRS.comwww.thinkSRS.com