TIMING, TEST & MEASUREMENT 5071A Primary Frequency Standard KEY FEATURES The 5071A primary frequency standard has 5071A—MEETING THE NEEDS OF • the accuracy and stability you need for both LEADING-EDGE METROLOGY AND Menu-driven Operation laboratory and field applications. A stability CALIBRATION LABS • Easy-to-read Clock and Message specification for 30-day averaging time means Timekeeping and National Standards Displays the 5071A will keep extremely predictable Laboratories verify the stability and accuracy • Complete Status Information time and phase for long periods. Further, the of their in-house cesium standards to 5071A can be used for long-term averaging Coordinated Universal Time (UTC), provided • Automatic Logging of Major of noisy signals such as GPS. by the Bureau International des Poids et Internal Events Mesures (BIPM) in Paris. A standard’s accu- • Full Clock and Frequency Control The 5071A is easy to use. No more manual racy and reliability determine the quality of • Automatic Synchronization of start-up steps or complicated adjustments— service these timekeeping labs provide. Of everything is automatic. A logical menu even greater concern is the stability of a 1PPS Signal structure simplifies front panel operations, standard. Stability directly affects a laboratory’s • CE Compliant selections, and status reporting. Remote ability to deliver timekeeping and calibration control features tailor the 5071A for complete services to its clients. operation and manageability in virtually any KEY SPECIFICATIONS location. The 5071A offers exceptional stability and • Standard Long-Life Cesium is the first cesium standard to specify its Beam Tube The 5071A is a direct descendant of and stability for averaging times longer than one -12 – Accuracy: ±1x10 replacement for the veteran 5060A, 5061A day. The instrument takes into account – Environmental Stability: and 5061B cesium standards. This innovative environmental conditions that can heavily 13 product is the result of more than 35 years influence a cesium standard’s long-term ≤1x10 Frequency Change for Any Combination of Environmental of experience in the precision frequency stability. Digital electronics continuously standard business. monitor and optimize the instrument’s Conditions operating parameters. -14 – Long-Term Stability: ≤5x10 for 5-Day Averaging Time • Optional High-performance Tube -13 – Accuracy: ±5.0E – Environmental Stability: -14 ≤8x10 Frequency Change for Any Combination of Environmental Conditions -14 – Long-Term Stability: ≤1.0x10 for 5-Day Averaging Time 5071A Primary Frequency Standard Thus, the 5071A’s response to environ- Because of their accurate time refer- UNSURPASSED STABILITY mental conditions such as temperature ence, GPS signals processed by a good The 5071A high-performance cesium and humidity are virtually eliminated. GPS timing receiver, can provide highly beam tube guarantees stability to be 14 The 5071A primary frequency standard accurate time and frequency outputs. better than 1 part in 10 for averaging maintains its accuracy and stability, However, since GPS receivers rely times of five days or greater. The 5071A even in unstable environments. on very low level microwave signals is the first cesium standard to specify from the satellites, they sometimes stability for averaging times longer than 5 SATELLITE COMMUNICATIONS lose accuracy because of interfering 1x10 seconds (approximately one day). Stable frequency generation is required signals, local antenna problems, or to transmit and receive signals properly bad satellite data. The 5071A is also the first cesium between ground terminals and com- standard to specify and guarantee a munication satellites. Frequency In spite of these problems, a GPS timing flicker floor. Flicker floor is the point flexibility is also needed to adjust for receiver can be an excellent backup at which the standard’s stability (σ y satellite-to-satellite carrier-frequency and reference to a local 5071A primary (2,τ)) does not change with longer differences. The 5071A’s state-of-the-art frequency standard. The GPS receiver averaging. The high-performance 5071A technology produces offset and primary provides an independent reference Flicker floor is guaranteed to be 1 part 14 frequencies with the same guaranteed that can be used to verify the accuracy in 10 or better. Long-term measure- stability. of a caesium standard, or it can be ments at the National Institute of used as a temporary backup should Standards and Technology (NIST) show For secure communications, precise the caesium standard need repair. The that the flicker floor is typically better -15 timing synchronization ensures that local 5071A standard has better short- than 5x10 . encrypted data can be recovered quickly. term stability, better output signal Frequency-agile signals also require quality, and is not perturbed by inter- Unstable environments are normal exact synchronization between trans- fering signals, intermittent signal loss, for many cesium standard applications. mitter and receiver during channel hops. or bad satellite data. The 5071A features a number of microprocessor-controlled servo loops The 5071A automates the synchroniza- With these characteristics, the synergy which allow it to virtually ignore tion to any external 1PPS signal, greatly created by combining a good quality changes in temperature, humidity, simplifying this aspect of satellite GPS timing receiver and a 5071A pri- and magnetic fields. communications. mary frequency standard can produce a highly robust, inexpensive, and The 5071A delivers exceptional per- THE 5071A AND GPS redundant frequency and time system. formance over very long periods of time, The 5071A primary frequency standard greatly increasing the availability of can work very well with a GPS timing EXCEPTIONAL ACCURACY critical time and frequency services. receiver to produce and maintain highly The intrinsic accuracy of the improved Actual measurements made at NIST accurate time and frequency. cesium beam tube assures that any have demonstrated that a 5071A with high-performance 5071A will power up the High- Performance CBT will drift -14 The GPS system provides accurate to within ±5.0E-13 of the accepted stan- no more than 5x10 over the entire life time, frequency, and location informa- dard for frequency. This is achieved of the CBT. tion worldwide by means of microwave under full environmental conditions in radio broadcasts from a system of 30 minutes or less—and without the satellites. Timing accuracy for the GPS need for any adjustments or alignments. system is based, in large part, on the accuracy and stability of a number of 5071A primary frequency standards. These standards are maintained by the GPS system, the US Naval Observatory, and various timing laboratories around the world which contribute to UTC, the world time scale. 2 5071A TRADITIONAL RELIABILITY Instrument State HIGH-PERFORMANCE CESIUM BEAM The 5071A has demonstrated an average Overall status is displayed, including TUBE mean time between failures (MTBF) of any warnings in effect. Key instrument The 5071A high-performance cesium greater than 160,000 hours since its parameters such as C-field current, beam tube is optimal for the most introduction in 1992. This data is based electron multiplier voltage, ion pump demanding operations. The high on actual field repair data. Backing up current, and cesium beam tube oven performance tube offers a full- this reliability is a 12-year warranty on voltage are available. You can initiate environment accuracy specification of the Standard Long-Life Cesium Beam a hard copy report of this data on your ±5.0E-13—two times better than the Tube and a five-year warranty for the printer with the push of a button. specification for the standard tube. highperformance tube. Stability is also significantly improved. Clock Control The high-performance tube reaches a -14 Complete repair and maintenance Set the time and date, schedule Flicker floor of 1x10 or better, and services are available at four strategi- leapseconds, adjust the epoch time (in long-term measurements at NIST show cally located service centers worldwide. 50-ns steps), and automatically synchro- that the flicker floor is typically better -15 nize the 1PPS signal to within 50 ns of than 5x10 . FULL TRACEABILITY TO NIST an external pulse using this menu. Symmetricom provides NIST traceability INTEGRATED SYSTEMS AND to the accuracy measurements made Instrument Configuration REMOTE OPERATION on every 5071A. Traceability to NIST is Set the instrument mode (normal or Today, cesium standards are often maintained through the NIST-supplied standby) and assign frequencies (5 or integrated into telecommunication, Time measurement and analysis sys- 10 MHz) to the two independently pro- satellite communication, or navigation tem (TMAS). This service exceeds the grammable output ports; configure systems as master clocks. To accom- requirements of MIL-STD-45662A and the RS-232C data port. modate these environments, the 5071A can be a valuable tool in demonstrat- provides complete remote control and ing traceability to your customers. Event Log monitoring capabilities. Instrument Significant internal events (power functions and parameters can be STRAIGHTFORWARD OPERATION source changes, hardware failures, interrogated programmatically. Internal microprocessor control makes warning conditions) are automatically start-up and operation of the 5071A recorded with the time and date of Communication is accomplished via extremely simple. Once connected to their occurrence. A single keystroke the standard commands for program- an ac or dc power source, the 5071A produces a hard copy on your printer mable instruments (SCPI) language automatically powers up to its full for your records. and a dedicated RS-232C port. Also, accuracy specifications. No adjustments a rear panel logic output can be pro- or alignments are necessary during Frequency Offset (Settability) grammed to signal when user-defined power-up or operation for the life of Output frequencies may be offset by “abnormal” conditions exist. 9 the cesium tube. as much as 1 part in 10 in steps of 15 approximately 6.3 parts in 10 . All For uninterruptible system service, an An intuitive menu structure is accessible product stability and output specifica- internal battery provides 45 minutes of via the front panel LCD display and tions apply to the offset frequency. backup in case of ac power failure. Thus, keypad. These menus—Instrument the 5071A can be managed easily even State, Clock Control, Instrument Utilities in the most remote locations. Configuration, Event Log, Frequency The firmware revision level and cesium Offset and Utilities—logically report beam tube identification information status and facilitate control of the can be displayed. instrument. These functions are described below. 3 • 5071A SPECIFICATIONS Accuracy and long term stability Conditions - and any combination of ELECTRICAL SPECIFICATIONS Temperature 0°C to 50°C • Frequency outputs Humidity 0 to 85% (40°C max) 1 Magnetic field dc, 55, 60Hz, 2G peak any orientation Frequency 5MHz & 10MHz Shock and vibration 100-mm drop Format Sine Amplitude ≥1Vrms Harmonic ≤-40dBc Standard High Non harmonic ≤-80dBc Performance Performance Connector N Accuracy ±1.0E-12 ±5.0E-13 Load impedance 50Ω Frequency change vs ±1.0E-13 ±8.0E-14 Location rear panel environment Isolation between ports ≥110dB (typical) Warm-up time (typical) 30 Min 30 Min Reproducibility ±1.0E-13 ±1.0E-13 Frequency 100kHz & 1MHz Settability Format Sine Range ±1.0E-9 ±1.0E-9 Amplitude ≥1Vrms Resolution 6.3E-15 6.3E-15 Harmonic ≤-40dBc Control: Via RS-232 port Load impedance 50Ω • Stability Standard High Location rear panel Performance Performance Connector BNC Avg. Time (s) Allan Deviation Allan Deviation • Timing outputs 0.01 ≤7.5E-11 ≤7.5E-11 Format 1PPS 0.1 ≤1.2E-11 ≤1.2E-11 Amplitude ≥2.4V into 50Ω 1 ≤1.2E-11 ≤5.0E-12 (TTL Compatible) 10 ≤8.5E-12 ≤3.5E-12 Pulse width 20us 100 ≤2.7E-12 ≤8.5E-13 Rise time ≤5ns 1,000 ≤8.5E-13 ≤2.7E-13 -9 (slew rate>10 volts/second at 1.5V) 10,000 ≤2.7E-13 ≤8.5E-14 Jitter ≤1ns rms 100,000 ≤8.5E-14 ≤2.7E-14 Connector BNC 5 days ≤5.0E-14 ≤1.0E-14 Load impedance 50Ω 30 days ≤5.0E-14 ≤1.0E-14 Location One front panel Flicker floor Two rear panel Timing Inputs Guaranteed ≤5.0E-14 ≤1.0E-14 Automatic synchronization to within 50ns of reference pulse Typical ≤1.5E-14 ≤5.0E-15 Sync input (2) 1PPS SSB Phase noise (each may be independently armed) Offset (Hz) 10MHz Output 5MHz Output Amplitude +2 to +10V Max 1 ≤-100dBc ≤-106dBc Pulse width 100nS min to 100us max 10 ≤-130dBc ≤-136dBc Rise time ≤50ns 100 ≤-145dBc ≤-145dBc Jitter ≤1ns rms 1,000 ≤-150dBc ≤-150dBc Connector BNC 10,000 ≤-154dBc ≤-154dBc Load impedance 50Ω 100,000 ≤-154dBc ≤-154dBc Location One front panel One rear panel ENVIRONMENTAL AND PHYSICAL SPECIFICATIONS • General environment Manual sync Temperature Range -0.5 to +0.5s Resolution 50ns Operating 0°C to 55°C Non-operating -40°C to 70°C Humidity 0 to 95%RH (45C max) Remote System Interface and Control Magnetic field dc, 55, 60Hz 0 to 2 gauss peak - any orientation RS-232-C (DTE Configuration) Atmospheric pressure ≤1E-13 change in frequency for pressure down Complete remote control and interrogation of all instrument functions and parameters to 19kPa (equivalent to an altitude of 12.2km) Software command set: Standard Commands for Programmable Shock and vibration Instruments (SCPI), version 1990.0 adapted for Mil-T-28800D, Type III, class 5 RS-232C Hammer Blow Shock Test, Mil-S-901C, Grade A, Class 1, Type A Mile-STD, 167-1 (phase noise) Connector 9-pin male rectangular D subminiature type EMI: Conducted and radiated emissions per CISPR Location rear panel 11/EN 55011, Group 1, Class A EMC: per MIL-STD-461C, Part 7, Class B dc magnetic field up to 7.8 Gauss Alarm (TTL) BNC Output TTL High, normal TTL low, fault Circuit is TTL open collector with internal pull-up resistor. Circuit can sink up to 10mA Location rear panel 4 5071A AC Power requirements Operating voltage 100, 120 Vac ±10%, 45 to 440 Hz 220, 240 Vac ±10%, 45 to 66 Hz Frequency 45 to 440Hz 45 to 66Hz Power Operating 50W (Standard Performance) 58W (High Performance) Warm-up 100W DC Power requirements 22 to 42 VDC Operating 45W (Standard Performance) 50W (High Performance) Warm-up 85W Internal Standby battery Capacity 45 minutes from full charge Charge time 16 hours max from fully discharged state Charge source ac input power supply Dimensions/weight Height 133.4 mm Width 425.5 mm Depth 523.9 mm Weight 30 kg MTBF >160,000 hrs. 1 Each output can be set to either 5 or 10MHz from the front panel or by remote control. 2 Lifetime accuracy (high-performance CBT only) after a minimum two-month warm-up. Change no more than 5.0E-14 for the life of the CBT. ORDERING INFORMATION Part No High Performance Tube 5071A-C001 Standard Performance Tube 5071A-C002 High Performance Tube with 48 VDC Option 5071A-C007 Standard Performance Tube with 48 VDC Option 5071A-C008 Rear View SYMMETRICOM, INC. 2300 Orchard Parkway San Jose, California 95131-1017 tel: 408.433.0910 fax: 408.428.7896 info@symmetricom.com ©2009 Symmetricom. Symmetricom and the Symmetricom logo are registered trademarks of Symmetricom, Inc. All other trademarks are the www.symmetricom.com property of their respective companies. All specifications subject to change without notice. DS/5071A/D/1009/PDF