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Symmetricom 5071A, Assembly And Service Manual

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Symmetricom 5071A Assembly And Service Manual Download Page 66

2. Service 

Top-Level Diagnostic Tree (Diagnostic Section 1)

 

 50 

FIRST WORD (Rightmost word): 

- 

 

  0     0     0     0     0     0     0     0  

⇐

 

Hex digit 

 

 

/ \   / \   / \   / \   / \   / \   / \   / \ 

00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  

⇐

 

Binary digit 

|  |  |  |  |  |  |  |  |  |  |  |  |  |  |   \_1. Servo offset - No Message 
|  |  |  |  |  |  |  |  |  |  |  |  |  |   \_2. CBT shutdown: <#> - Fatal Error 
|  |  |  |  |  |  |  |  |  |  |  |  |   \_3. VCXO near tuning limit - Warning 
|  |  |  |  |  |  |  |  |  |  |  |   \_4. VCXO at tuning limit - Fatal Error 
|  |  |  |  |  |  |  |  |  |  |   \_5. C-field current at range limit - Fatal Error 
|  |  |  |  |  |  |  |  |  |   \_6. E-multiplier voltage at range limit - Message 
|  |  |  |  |  |  |  |  |   \_7. Signal gain at range limit - Warning 
|  |  |  |  |  |  |  |   \_8. Internal DC supply out of range - Warning 
|  |  |  |  |  |  |   \_9. Mass spec supply regulation failure - Fatal Error 
|  |  |  |  |  |   \_10. Hotwire supply regulation failure - Fatal Error 
|  |  |  |  |   \_11. CBT oven supply regulation failure - Fatal Error 
|  |  |  |   \_12. CBT oven voltage at range limit - Fatal Error 
|  |  |   \_13. RF amplitude at range limit - Warning 
|  |   \_14. Microprocessor PLL unlocked - Warning 
|   \_15. 87 MHz PLL unlocked - Message 
 \_16. Unused bit - always zero. 

SECOND WORD: 

  0     0     0     0     0     0     0     0  

⇐

 

Hex digit 

 / \   / \   / \   / \   / \   / \   / \   / \ 

00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  

⇐

 

Binary digit 

|                       |  |  |  |  |  |  |   \

_17. DRO unlocked - Message

 

|                       |  |  |  |  |  |   \

_18. VCXO oven error - Message

 

|                       |  |  |  |  |   \

_19. CBT signal loss - Fatal Error

 

|                       |  |  |  |   \

_20. CBT signal low - Warning

 

|                       |  |  |   \

_21. Servo system is in manual mode - Warning

 

|                       |  |   \

_22. Attempted lock on wrong peak - Fatal Error

 

|                       |   \

_23. Center peak saturated - Message

 

 \-----

reserved

--------/   

 
Example Error-Code Interpretation 

- 

You can create a fatal error by disconnecting A5P2 from A5 after the instrument has 
powered-up and is running (wait up to 35 seconds for the software to confirm this 
failure).  When the attention LED begins flashing, you're ready to read the error code 
from the log. 

 

- 

Typical log display:  

Error code: 000000a0 20000000

 

 

- 

By using the above error-message map, the following information may be decoded: 
- 

15. 87 MHz PLL unlocked - Message 

- 

19. CBT signal loss - Fatal Error  (This is the event that initiated the shut-down.) 

- 

20. CBT signal low – Warning 

NOTE 

You must power-off, reconnect A5P2, and then power-on again 
to clear this error

. 

 

Summary of Contents for 5071A

Page 1: ...5071A Primary Frequency Standard Assembly Level Service Manual Rev B July 3 2007 Part Number 05071 90040 ...

Page 2: ......

Page 3: ...13501 can then be saved to your computer hard disk This software is only available for use with a Windows based PC There are a limited number of 5071A replaceable parts available The 5071A Primary Frequency Standard is a very precise and complex product and Symmetricom strongly recommends that they be sent in for repairs and post repair performance testing However there are some assemblies such as...

Page 4: ... the product is set to match the available line voltage and the correct fuse is installed Refer to instructions in Chapter 1 of this Manual Before Cleaning Disconnect the product from operating power before cleaning Clean only with lightly damp cloth and mild detergents Do not get unit wet Safety Earth Ground An uninterruptible safety earth ground is recommended from the mains power source to the ...

Page 5: ...ional load the Model 5071A Unit may place on the supply circuit Overloading the supply circuit may adversely affect the supply wiring and over current protection Reliable Earthing Maintain reliable earthing grounding of rack mounted equipment Pay particular attention to supply connections other than direct connections to the branch circuit e g use of power strips CAUTION ________________ Damage to...

Page 6: ...ROUND BE CONNECTED TO A RELIABLE EARTH GROUND ANY INTERRUPTION OF THE PROTECTIVE GROUNDING CONDUCTOR INSIDE OR OUTSIDE THE INSTRUMENT OR DISCONNECTING THE PROTECTIVE EARTH TERMINAL WILL CAUSE A POTENTIAL SHOCK HAZARD THAT COULD RESULT IN PERSONAL INJURY GROUNDING ONE CONDUCTOR OF A TWO CONDUCTOR OUT LET IS NOT SUFFICIENT PROTECTION AVERTISSEMENT RELIER CET APPAREIL À UNE PRISE DE COURANT AVEC CONT...

Page 7: ...for DC power source hookup The Unit Chassis must be grounded for proper safety WARNING ENSURE THAT A DISCONNECT DEVICE SUCH AS A SWITCH WITH THE APPROPRIATE VOLTAGE CURRENT RATING IS PROVIDED WHEN CONNECTING A DC POWER SOURCE TO THE VDC OPERATION MODEL AVERTISSEMENT S ASSURER QU UN DÉBRANCHER L APPAREIL TEL QU UN COMMUTATEUR AVEC LE CLASSEMENT DE TENSION COURANT APPROPRIÉ EST FOURNI EN CONNECTANT ...

Page 8: ...ch does not execute its programming instructions due to such defects Symmetricom does not warrant that the operation of Symmetricom products will be uninterrupted or error free If Symmetricom is unable within a reasonable time to repair or replace any product to a condition as warranted the customer will be entitled to a refund of the purchase price upon prompt return of the product Symmetricom pr...

Page 9: ...CLUSIVE REMEDIES EXCEPT AS INDICATED ABOVE IN NO EVENT WILL SYMMETRICOM OR ITS SUPPLIERS BE LIABLE FOR LOSS OF DATA OR FOR DIRECT SPECIAL INCIDENTAL CONSEQUENTIAL INCLUDING LOST PROFIT OR DATA OR OTHER DAMAGE WHETHER BASED IN CONTRACT TORT OR OTHERWISE For consumer transactions in Australia and New Zealand the warranty terms contained in this statement except to the extent lawfully permitted do no...

Page 10: ...ent Directive WEEE 2002 95 EC For more information about Symmetricom s WEEE compliance and recycle program please visit the Symmetricom s WEEE RoHS website at http www symmetricom com About_Us WEEE_RoHS_Initiatives htm RoHS Restriction of the Use of Certain Hazardous Substances Directive 2002 95 EC This product falls under the category of Monitoring and Control Instruments Equipment Category 9 as ...

Page 11: ...erification 8 5071A Complete Performance Tests 10 Test 1 Output Signals Harmonic Distortion and Spurious Signals Check 10 Test 2 Frequency Accuracy 18 Test 3 Stability 21 Performance Test Record 22 2 Service 25 Introduction 25 Returning the Instrument to Symmetricom for Service 26 To Provide Repair Information 26 To Pack in the Original Packaging Materials 26 Pre Troubleshooting Information 27 Saf...

Page 12: ...up Subsection 2 74 RF Chain Diagnostic Tree Functional Group Subsection 3 77 C Field Diagnostic Tree Functional Group Subsection 4 81 Assembly Module Diagnostic Trees Diagnostic Section 3 82 A2 CBT Controller Diagnostic Tree A M Subsection 1 83 A2 Hot Wire Ionizer Diagnostic Tree 84 A2 Thermistor Diagnostic Tree 86 A2 Mass Spectrometer Diagnostic Tree 88 A2 Cesium Oven Diagnostic Tree 90 A5 Diagno...

Page 13: ...Reassembly 160 Introduction 160 Tools Required 160 Do This First 161 To Remove the Covers 161 To remove the A2 CBT Control Assembly 162 To Remove Any Other PC Boards 162 To Remove A1 Motherboard Assembly 162 To Remove A10 Output Frequency Distribution Amplifier Module 163 To Remove A12 Dc Dc Power Converter Module 164 To Remove A13 Front Panel Module 165 To Remove A14 Signal Amplifier Module 166 T...

Page 14: ...Replaceable Parts 174 Introduction 174 Replaceable Parts Table 174 How To Order A Part 174 Parts Identification 174 Contacting Symmetricom 175 6 Specifications 179 Introduction 179 7 Service and Support 180 Index 182 ...

Page 15: ...the faulty assembly or module by using the procedures in Chapter 2 Service The procedures in Chapter 4 Replacing Assemblies enable you to remove and replace defective assemblies or modules Text Conventions used in this manual Throughout this manual there are symbols used to denote special meanings These are explained below These separators mark where information may be any value or text otherwise ...

Page 16: ...warranted specifications Chapter 2 Service is divided into five sections Section 1 contains instructions for returning the Standard to Symmetricom for service Section 2 contains pre troubleshooting information and Sections 3 4 and 5 provide the diagnostic troubleshooting tree procedures diagnostic trees to isolate faulty assemblies and or modules Chapter 3 Theory of Operation provides two levels o...

Page 17: ... 5071A Primary Frequency Standard using the specifications listed in Chapter 6 Specifications Three types of tests are provided Operational Verification Complete Performance Tests RS 232 Verification Operational Verification The Operational Verification test is an abbreviated series of checks that may be performed to give a high degree of confidence that the instrument is operating properly withou...

Page 18: ...lled out on this page and the appropriate test cables adapters listed on page 6 If diagnostic troubleshooting is required use the test equipment called out on this page page 5 and the appropriate test cables adapters listed on page 6 Table 1 1 Recommended Test Equipment Instrument Required Characteristics Use Model General Purpose Oscilloscope At least 100 MHz bandwidth Input 1 MΩ OV T HP Agilent ...

Page 19: ...olution 100 kHz Division Center Frequency Accuracy 1 PPM Input Up to 1 watt input capability Dynamic Range 100 dB T HP Agilent 8566A B Input Probe 10 1 Divider included with 54600A oscilloscope T HP Agilent 10071A Input Probe 1 1 1 MΩ for 50 Ω measurements T HP Agilent 10070A RF Signal Generator Frequency Range 80 MHz Power 7 dBm T HP Agilent 8656B Pulse Generator Repetition Rate 10 Hz Pulse Width...

Page 20: ...jack SMA jack to SMA plug Right Angle SMA plug to SMA plug SMA jack to SMA jack SMB jack to SMB jack SMB plug to SMB plug SMC jack to SMC jack SMC plug to SMC plug T HP Agilent 10100C 0960 0496 1250 0080 1250 0832 1250 0831 1250 1236 1250 1857 1250 0780 1250 1250 1250 1249 1250 1159 1250 1158 1250 0672 1250 0669 1250 0827 1250 1113 Microwave Test Cable SMA male at both ends 10dB loss at 10 GHz T G...

Page 21: ... displayed on the LCD in sequence a The message waiting for ion pump start may appear If so it could stay on for up to 20 minutes before the following messages appear b Warming up this indicates self test passed successfully c Lowering E_mult voltage d Setting Osc Control e Setting RF amplitude f Setting E_mult voltage g Logging signal levels h Setting C field i Locking servo loops j Operating nor...

Page 22: ...5 MHz output Port 2 10 MHz output RS 232C Baud rate 2400 Data bits 8 Parity none Stop bits 1 System Logs Printer log disabled Error log lock completed These first time power up configurations can be changed by using the front panel controls See the section titled Setting the Output Port Frequency in the 5071A Operating and Programming Manual for instructions on how to do this ...

Page 23: ...el number HP Agilent 10100C HP Agilent 54600A General Purpose 100 MHz Oscilloscope or equivalent To check the rear panel output connectors quickly for the presence of valid output signals perform the following steps NOTE The LCD display backplane light will turn off after approximately 4 minutes to conserve energy if no front panel key is pressed Press any key to turn the backplane light back on 1...

Page 24: ...tion for your remote operation needs as shown in Figure 1 2 2 Ensure that the 5071A and your data communications equipment terminal are powered up and have passed their own self tests 3 On your terminal press the Enter or Return key several times 4 Observe the returned scpi or E xxx prompt on the terminal screen if the above prompt appears the RS 232 Verification check passed If the prompt does no...

Page 25: ...1 Performance Tests Verifying Specifications 5071A Operational Verification 9 Figure 1 2 RS 232C Cabling Setups ...

Page 26: ...Spurious Signals Check A Harmonic Distortion Check for the 5 and 10 MHz Outputs Harmonics on the 10 MHz and 5 MHz output signals must be more than 40 dBc below the fundamental To perform this check a spectrum analyzer is tuned to the fundamental frequency and an amplitude reference is established The output frequency spectrum is then examined to determine fundamental to sideband amplitude relation...

Page 27: ...h are in the marker menu area d Set both the resolution bandwidth RES BW and the video bandwidth VIDEO BW to 1 kHz Enter the 1 kHz values using the numeric and unit keys The RES BW and VIDEO BW values are displayed at the bottom of the screen NOTE The sweep time is 125 seconds DO NOT adjust the sweep time manually e Press the CONT button in the sweep menu area to begin a new sweep f When the new s...

Page 28: ...ious Signal Check for the 5 and 10 MHz Outputs Non harmonically related spurious signals on the 5 and 10 MHz outputs must be more than 80 dBc below the output signal levels To perform this test a spectrum analyzer is tuned to the 5 or 10 MHz signal and an amplitude reference is established The output frequency spectrum is then examined at 1 MHz on either side of the center frequency to determine t...

Page 29: ...ET button and allow the analyzer to go through its auto range algorithm this will take about 5 seconds b Press the DISP LINE display line button in the marker menu and adjust the line to 80 0 dBc c Press the PEAK SEARCH button and then the MKR REF LVL button both are in the marker menu area d Set both the resolution bandwidth RES BW and the video bandwidth VIDEO BW to 1 kHz Enter the 1 kHz values ...

Page 30: ...etween 9 MHz and 11 MHz for the 10 MHz output 4 On the 5071A set output ports 1 and 2 to 5 MHz using the front panel controls 5 Repeat step 3 6 Connect 5071A Port 2 to the 3585B Spectrum Analyzer and repeat steps 2 through 5 to test Port 2 7 Record the actual reading in the appropriate place in the Performance Test Record C Harmonic Distortion Check for the 1 MHz Output Harmonics on the 1 MHz outp...

Page 31: ...0 MHz using the numeric and unit keys in the entry menu c Press the DSP LINE button and move the display line to 40 0 dBc d Press the PEAK SEARCH button then the MKR REF LVL button e When the new sweep has passed through the fundamental frequency press the OFFSET and the ENTER OFFSET buttons in the marker menu area Verify that both the offsetfrequency Hz and the offset level dB go to zero 0 Hz and...

Page 32: ...s All harmonics must be 40 dBc with respect to the fundamental frequency Procedure If you are using the HP Agilent 3585B Spectrum Analyzer follow the steps below to test for harmonic signals on the 100 kHz output If you are using a different spectrum analyzer use these steps as a guide for operation of that analyzer 1 Connect the 5071A 100 kHz output to the 3585B Spectrum Analyzer as shown in Figu...

Page 33: ... the marker menu area Verify that both the offset frequency Hz and the offset level dB go to zero 0 Hz and 0 dB should be displayed at the top of the screen If necessary press and hold the ENTER OFFSET button to zero out the marker offsets h When at least one sweep has completed look for any signals that appear on or above the 40 dBc display line at multiples of 100 kHz up to 500 kHz Use the knob ...

Page 34: ...rd NOTE In this test the reference standard must be of known accuracy The measurement time must be of sufficient length so the accuracy of the measurement is not impaired by the stability of either the reference standard or the unit under test If the reference standard is a 5071A with the High Performance CBT the accuracy measurement must be made for 24 hours if the unit under test is a Long Life ...

Page 35: ...O Adjust the ZERO SCALE control for a zero reading on the meter Then adjust the recorder for a zero indication 6 Set K34 59991A switch to FULL and adjust FULL SCALE control for a full scale reading on the recorder 7 Check both ZERO and FULL SCALE settings on the recorder and readjust if necessary 8 Set K34 59991A switch to OPER for normal operation 9 The recorder now provides a continuous record o...

Page 36: ...4 10 9 2 88 104 4 9 10 13 or 4 9 parts in 1013 This shows that frequency difference between the unit under test and the reference is 4 9 parts in ten to the 13th This is only an example The measured frequency accuracy of a 5071A should be 1 x 10 12 or better for a Long Life Standard or 2 x 10 13 or better for a high performance unit NOTE The final computation should include the accuracy of the ref...

Page 37: ...rces of noise For more information on how to make this measurement see NIST Technical Note 1337 available from US Government Printing Office Washington DC USA This is an excellent theoretical as well as technical reference for this measurement Record the actual reading in the appropriate place in the Performance Test Record This completes the performance test B Frequency Domain This measurement re...

Page 38: ...S 232 Serial Port Verification _______ ______ _______ _______ _______ _______ Complete Performance Tests Test Number Description Actual Reading Limits 1 Output Signals Harmonic Distortion and Spurious Signals Check A Harmonic Distortion Check for the 5 and 10 MHz Outputs B Non harmonic Spurious Signal Check for the 5 and 10 MHz Outputs C Harmonic Distortion Check for the 1 MHz Output D Harmonic Di...

Page 39: ...formance Tests 23 Test Number Description Actual Reading Limits 2 Frequency Accuracy ____________ Long Life 1x10 12 High Performance 2x10 13 3 Stability A Time Domain B Frequency Domain ____________ ____________ See Specifications table in Chapter 6 of this manual ...

Page 40: ...1 Performance Tests Verifying Specifications 5071A Complete Performance Tests 24 ...

Page 41: ...ice This section provides you with step by step instructions on how to return the instrument for service Pre Troubleshooting Information This section provides you with pertinent information such as safety considerations recommended test equipment repair and after service considerations service accessories and assembly identification and location Diagnostic Trees and Procedures This section provide...

Page 42: ...uch damage will be evaluated and you will be provided with a quotation to repair such damage before regular repair or calibration can be performed It is also advised that all hazardous materials regulations for labeling be followed for your local and country laws The following web site will provide you with up to date instructions http www symmttm com 5071A Shipping Be sure to include the RMA with...

Page 43: ...e instrument in a safe condition Service instructions and adjustment procedures requiring removal of the instrument cover are for use by service trained personnel only To avoid dangerous electric shock do not perform any servicing or make any adjustments with the cover removed unless qualified to do so WARNING BEFORE APPLYING AC POWER THE INSTRUMENT AND ALL PROTECTIVE EARTH TERMINALS EXTENSION COR...

Page 44: ...ing subject to static charge buildup such as wool or synthetic materials 4 DO NOT handle components or assemblies in carpeted areas 5 DO NOT remove an assembly or component from its static shielding protection until you are ready to install it 6 AVOID touching component leads Handle by packaging only Disassembly and Reassembly Specifics Refer to the Chapter 4 Replacing Assemblies in this manual fo...

Page 45: ... front or rear panel ground terminals marked using the above procedure 4 INSULATION RESISTANCE TEST Tie the line and neutral pins of the power cord plug together Measure the resistance from the instrument enclosure chassis to the line and neutral pins of the power cord plug The minimum acceptable resistance is 2 MΩ Replace any component that results in a failure 5 LINE FILTER CABLE ASSEMBLY CHECK ...

Page 46: ...board for short PCAs 05071 60051 A4 6 7 8 diagnosis Extender board for long PCAs 05071 60052 A2 3 diagnosis 100 nA Current Source powered by A6 05071 60274 A14 diagnosis SO 8 SMT Dip clip 5250 ITT Pomona 1400 1708 SMT signal access SO 14 SMT Dip clip 5251 1400 1705 SMT signal access SO 16 SMT Dip clip 5252 1400 1706 SMT signal access SO 20 SMT Dip clip 5253 1400 1707 SMT signal access ...

Page 47: ...S Assembly 05071 68008 A9 Frequency Multiplier Module 05071 60292 A10 Output Frequency Distribution Amplifier Module 05071 60210 A11 A11 Power Steering Logic Assembly Std Power Steering Logic Assembly Opt 048 only 05071 68029 05071 68033 A12 A12 Dc Dc Power Converter Module DC DC Power Converter Module Opt 048 only 05071 60212 05071 60279 A13 Front Panel PC Assembly 05071 60213 A14 Signal Amplifie...

Page 48: ...2 Service Pre Troubleshooting Information 32 Figure 2 1 Instrument Top View ...

Page 49: ... module If the internal self test diagnostics are used without reference to this process misleading results may be obtained leading to improper and unproductive repair actions Besides the diagnostics other means are required to localize and isolate the problem PCA or module These include visual checks of LEDs and LCD display messages along with test equipment checks such as scope multimeter or spe...

Page 50: ...ions 1 Go to the beginning of the Top level diagnostic tree a If you already know the symptom operating problem go to the subsection in section 1 that provides its fault isolation b If you do not know what s wrong with a failed instrument start at the beginning of the Top level tree checking all items sequentially until you find a specific isolated fault or find a pointer to further details in sec...

Page 51: ...elf Tests 1 0 5 CBT Warm Up 1 0 6 Servo Lock Warning State 1 0 7 User Input Output Checks 1 0 8 5071A Profiling 1 0 8 1 Profiling Results Interpretation 1 0 8 2 Conclusion of Diagnostic Procedure 1 0 9 Delayed Failures Warnings and Messages 1 0 9 1 Delayed Fatal Errors 1 0 9 2 Delayed Warnings 1 0 9 3 Delayed Advisory Messages Power On Fatal Error Diagnostic Tree Diagnostic Subsection 1 1 1 1 Fata...

Page 52: ...cuits Test 1 3 8 RF Level Control Current Test Warning Message Diagnostic Tree Diagnostic Subsection 4 1 4 1 Warning Message Interpretation 1 4 2 Signal Gain at Range Limit CBT Signal Low 1 4 3 5071A Profiling CBT Performance Evaluation 1 4 4 Power Source is Batt Ignore this for Opt 048 1 4 4 1 Ac Line Operation Battery Indicator On 1 4 4 2 Instrument Ac Power Absent 1 4 4 2 1 A1C4 Voltage Test 1 ...

Page 53: ...rification procedure without any repair This could for example occur when the cesium beam tube CBT nears the end of its life In case of difficulty contact Symmetricom for assistance 1 0 0 First Power On 1 Remove the instrument from service 2 Remove all external power 3 Disconnect the internal standby battery See Operating and Programming manual pg 2 15 For Opt 048 ensure that the rear panel dc lin...

Page 54: ...t power steering circuit functional If Yes Go to 1 0 1 1 If No Replace the 48V Sub panel Assembly P N 05071 60277 and retest 1 0 1 1 Digital Supply Voltage Check 1 Install the short extender board part number 05071 60051 into the spare slot on the A1 motherboard 2 Use a DMM with a point tipped probe to verify 5V supply on the extender board test points QUESTION Is 5V between 5 28 to 5 50 volts If ...

Page 55: ... log LOG BROWSE menu selections 3 Clear the log use LOG CLEAR 4 Install the short extender board part number 05071 68051 into the spare slot on the A1 motherboard 5 Use a DMM with point tipped probes set for dc volts to measure the 5 12 and 12 volt supplies on the extender board test voltage points to chassis ground They should all be within the following ranges 5V 5 28 to 5 50 volts 12V 12 08 to ...

Page 56: ...TIL menu select TEST option and press Enter b Press INC to initiate the Self test cycle c Observe the front panel display CYCLES 0 when 0 changes to 1 or greater all Self tests have passed d If a Self test routine fails record the displayed message and attempt to continue the tests by pressing INC again e Press DEC to halt Self test execution QUESTION Did the 5071A pass all the Self tests If Yes G...

Page 57: ...Refer to chapter 1 page 1 8 to verify operation and page 1 7 in the Operating and Programming manual for checking the Sync inputs with a pulse source a Both 5 10MHz outputs b 1 MHz output c 100 kHz output d RS232 port e All 1PPS outputs f Both Sync inputs g Status Output 1 Use an oscilloscope to verify TTL high state 2 Put the instrument into Standby 3 Verify transition to TTL low state 4 Return t...

Page 58: ...nducted on an 5071A currently in use The procedure requires only that the instrument will run in Normal Operation mode 2 When the profiling software has generated its report use the following information to evaluate the results 1 0 8 1 Profiling Results Interpretation Signal to Noise Ratio The Signal to Noise Ratio is an estimate of the current overall operating condition of both the CBT and instr...

Page 59: ...the A19 frequency if the control value reaches 90 The adjustment procedure is provided at 3 9 1 7 and 3 9 1 8 1 0 8 2 Conclusion of Diagnostic Procedure If the results of the profiling procedure do not suggest CBT replacement the instrument can be returned to service If repairs have been made full performance testing or operational verification must be performed as described in chapter 1 If a 5071...

Page 60: ...rors are usually caused by a significant malfunction of one of the instrument s functional blocks These errors will usually prevent subsequent operation and can be diagnosed in the usual way using the top level diagnostic procedure 1 0 9 2 Delayed Warnings Warnings which occur in normal operation may not always require the instrument to be removed from service especially when some loss of performa...

Page 61: ... is absent on A3 1 Place the short extender board part number 05071 60051 into the available spare slot on the motherboard XOPTP1 and XOPTP2 2 Use an oscilloscope to verify that a 1 MHz signal is present at the test point labeled 1 MHz with an amplitude of 4 volts 50 duty cycle and a nominal 20 ns rise time QUESTION Is the 1 MHz signal present as specified If Yes Remove power replace A3 and retest...

Page 62: ...coupled timebase to 50 us div no auto trigger to verify the signals are toggling at A2J2 pins 2 and 3 following activation of the reset button on top of A3 The pulse levels should be approximately 4 0 Vp p Refer to the A2 connector pinout diagrams at the beginning of the A2 diagnostic trees opposite procedure 3 1 1 1 0 QUESTION Is there 5 V at pin 1 and a toggling signal present on pins 2 and 3 of...

Page 63: ... comp test short Go to A2 Thermistor tree beginning at 3 1 2 1 0 If TEST 2 CBT therm zero test CBT therm ones test Go to A2 Thermistor tree beginning at 3 1 2 1 0 If TEST 3 CBT Cs oven zero test num V CBT Cs oven ones test num V CBT Cs oven bit test bit num Go to A2 Cesium Oven tree beginning at 3 1 4 1 0 If TEST 4 CBT hw ion zero test num V CBT hw ion all 1 s test num V CBT hw ion bit test bit nu...

Page 64: ...emove power replace A11 and retest Failure of test 14 may occur with any combination of tests 2 3 4 5 9 and 10 1 2 2 Pps Interrupt Error Test 1 Install the short extender board part number 05071 60051 into the spare slot on the A1 motherboard 2 Use an oscilloscope with trigger level set to 1 5 volts no auto trigger and high impedance probe to check presence of 20 μs pulses with an amplitude greate...

Page 65: ...ation 1 Convert the two 8 character hexadecimal words in the error code into its two corresponding 32 bit binary words using the chart below 2 Divide the right most binary word into 16 fields each containing two adjacent bits 3 Divide the 14 right most bits of the second binary word into seven fields each containing two adjacent bits 4 Each of the 23 two bit fields corresponds to the output of an ...

Page 66: ...bit always zero SECOND WORD 0 0 0 0 0 0 0 0 Hex digit 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 Binary digit _17 DRO unlocked Message _18 VCXO oven error Message _19 CBT signal loss Fatal Error _20 CBT signal low Warning _21 Servo system is in manual mode Warning _22 Attempted lock on wrong peak Fatal Error _23 Center peak saturated Message reserved Example Error Code Interpretation You can ...

Page 67: ...ils 1 3 2 Warm Up Error Interpretation 1 Locate the most recent error should be at the end of the log 2 Record this error QUESTION What is the error All assembly module trees are in diagnostic tree section 3 RF chain and C field trees are in diagnostic tree section 2 If ERROR Cs oven failed ion pump overcurrent Go to 1 3 2 1 If ERROR Cs oven timeout Go to 1 3 5 If ERROR Osc oven timeout Go to 3 9 ...

Page 68: ...power and wait at least 60 seconds for the high voltage supplies to bleed down 2 Disconnect the Ion Pump high voltage HV connector from the CBT see Figure 2 1 Ensure that the end of the high voltage lead is clear of any conductors 3 Disconnect the flexible cable joining the CBT to A2J2 4 Power up the instrument and allow a few seconds for it to enter the Fatal Error mode 5 Observe the measured Ion...

Page 69: ...instrument fail in the same manner If Yes The CBT is possibly defective contact Symmetricom for further assistance If No Problem may be resolved retest 1 3 4 CBT Shutdown Message 1 Read the CBT shutdown message preceding the error code QUESTION What is the message If CBT shutdown thermistor open Go to A2 thermistor 3 1 2 1 0 diagnostic tree If CBT shutdown thermistor shorted Go to A2 thermistor 3 ...

Page 70: ...for assistance If No Continue diagnostic testing 1 3 6 CBT Background Signal Warm Up Errors These errors occur when the CBT background signal is not within acceptable limits after warm up This condition can be caused by a malfunction in the CBT itself or by various circuits that control it This procedure checks these alternatives NOTE The instrument self tests must pass successfully for the follow...

Page 71: ...he following procedure checks these alternatives 1 Test the RF chain by performing procedure 2 3 1 0 through 2 3 6 0 2 Test the C field circuit by performing procedure 2 4 1 0 through 2 4 3 0 QUESTION Did all diagnostic tests pass If Yes The microwave signal is adequate for satisfactory warm up completion Go to 1 3 7 1 If No Repair as required and retest 1 3 7 1 CBT Support Circuit Tests 1 Perform...

Page 72: ...A1J19 and set the DMM to measure at least 16 mA dc 3 Disconnect the CBT from A2 at A2J2 Cycle instrument power and wait for it to enter the Fatal Error mode 4 Observe and record the current measured at A1J19 5 Remove power and reconnect the CBT cable to A2J2 6 Reapply power to the instrument and verify that LCD displays Warming up 7 Quickly observe and record the average current at A1J19 8 Remove ...

Page 73: ... supply out of range Remove power replace A7 and retest If WARNING is Microprocessor PLL unlocked Remove power replace A3 and retest If WARNING is CBT signal low Go to 1 4 3 If WARNING is Power source is Batt Go to 1 4 4 If WARNING is RF amplitude at range limit Go to 1 3 7 Warning 21 relates to factory testing and will typically not occur during actual use 1 4 2 Signal Gain at Range Limit CBT Sig...

Page 74: ...rom the battery 1 Disconnect both batteries from the 5071A by a opening the rear battery compartment door then b disconnect the two connectors to the batteries QUESTION Does the instrument continue to operate or has all power been lost If still operating Go to 1 4 4 1 If power has been lost Go to 1 4 4 2 1 4 4 1 AC Line Operation Battery Indicator On Fault is most likely in A11 power steering logi...

Page 75: ... A1C4 Voltage Test Procedure 1 Measure the dc voltage across A1C4 large can filter capacitor QUESTION Is the voltage between 32 and 38 Vdc If Yes Remove power replace faulty 05071 60253 cable and retest If No Go to 1 4 4 3 QUESTION Is the voltage between 45 and 51 Vdc If Yes Remove power replace faulty 05071 60253 cable and retest If No Go to 1 4 4 3 1 4 4 3 LF1 T1 Transformer Fault Verification 1...

Page 76: ... Module diagnostic trees are located in diagnostic tree section 3 QUESTION Which I O was found at fault If 5 10 MHz Go to 3 5 1 0 A10 diagnostic tree If 1 MHz Go to 3 5 1 0 A10 diagnostic tree If 100 kHz Go to 3 5 1 0 A10 diagnostic tree If 1 PPS Go to 3 3 0 A8 diagnostic tree If 1 PPS Sync Go to 3 3 0 A8 diagnostic tree If RS 232 Confirm fault check datacomm config internal cables remove power re...

Page 77: ... with the ck5071a exe file and execute it at the DOS prompt The program will prompt you to enter the number of the COM port in use 1 or 2 and the Baud rate in use 4 Enter these values into the computer Soft key labels will appear at the bottom of the display when the program establishes communication with the 5071A operating system 5 Press Terminal emulator to start a terminal emulator program tha...

Page 78: ...operly or suffered a system crash during execution 1 If the prompt is p4th A note the double in this prompt type h and press the Enter or Return key This should result in an error message and bring up a second prompt p4th A Proceed to step 2 below 2 If the prompt is p4thA type all lower case halt and press the Enter or Return key This should return you to the SCPI system with either the scpi or E ...

Page 79: ... Modulation The Depth of Modulation can help isolate faults to either the CBT or the instrument electronics A Band 3 modulation depth combined with a peak output current below 100 nA indicates deteriorating CBT performance Be sure to thoroughly diagnose the entire instrument before considering the A17 CBT to be at fault Contact Symmetricom for further assistance Signal to Noise Ratio The Signal to...

Page 80: ...strument Status summary Operating normally Steered Power source ac Log status 101 entries Last Message in Log Lock completed Fractional frequency offset 314e 15 VCXO control value 13 72 Internal temperature 42 6 C Cesium Beam Tube measured data Ion Pump current 0 2 uA Peak output current 101 nA Electron multiplier voltage 1234 V Depth of Modulation Band 1 see note Signal to noise ratio Band 1 see ...

Page 81: ...red Message 87 MHz PLL unlocked This message indicates an RF chain problem leading to an erroneous voltage level in the A5 module This message may be associated with a fatal error Go to 1 3 7 Message DRO unlocked This message indicates an RF chain problem leading to an erroneous voltage level in the A15 module This message may be associated with a fatal error Go to 1 3 7 Message VCXO Oven error Th...

Page 82: ...s located in section 3 The names of the functional groups are listed below in order with the assemblies and modules that comprise them 1 Power supply diagnostic tree 2 1 1 1 0 A1 motherboard assembly A11 Power steering logic assembly A12 Dc to Dc Converter module LF1 Line filter module cable assembly T1 Toroidal power transformer B1 24V Internal Standby Battery Does not apply for Opt 048 2 Analog ...

Page 83: ...1 1 1 2 1 1 1 1 A12 Power Input Test 1 Remove the instrument top bottom covers and inner shield 2 Apply ac power to the instrument 3 Use a DMM to measure the input voltage Vin at the A12 module across the Vin and Vin return power input lugs on the module 4 Verify that the voltage present is between 32 and 38 Vdc 45 and 51 Vdc for Opt 048 with no more than 1 Vrms ripple QUESTION Does the measured v...

Page 84: ...the A11 to A1 cable 05071 60253 or the A12 module cable 1 Use a DMM to measure the voltage across A1C3 2 Verify that the voltage present is between 32 and 38 Vdc 45 and 51 Vdc for Opt 048 with no more than 1 Vrms ripple QUESTION Does the measured voltage meet specifications If Yes Remove power replace A12 and retest If No Remove power replace A11 or cable 05071 60253 or both and retest 2 1 1 1 4 A...

Page 85: ...ac line toroidal transformer connector going to A1J5 3 Apply ac line voltage again 4 Check the ac line fuse immediately for possible open condition QUESTION Did the line fuse blow If Yes Go to 2 1 2 2 0 If No Go to 2 1 2 3 0 2 1 2 2 0 AC Line Fuse Fault Isolation Rule Out LF1 T1 Fault is between the ac line connector on the back panel the ac line toroidal transformer or the cable connecting the tw...

Page 86: ...her isolated 1 Reconnect all connectors Install a new fuse if necessary 2 Disconnect A1P2 from A1J2 on A1 motherboard This breaks the circuit at the dc dc power converter module A12 3 Apply ac line voltage again 4 Check the ac line fuse immediately for possible open condition QUESTION Did the ac line fuse blow If Yes Go to 2 1 2 5 0 If No Go to 2 1 3 0 0 Fault is in the A12 power supply module or ...

Page 87: ...tput voltages were accidentally shorted to another power supply output voltage the protection circuits within the A12 module will shut down all the output voltages In order to recover from this protection mode the ac power must be removed from the instrument for at least 30 seconds Then reapply ac power and all output voltages should return to normal If they do not replace A12 and retest 2 1 3 1 0...

Page 88: ...elow specification replace A1 and retest 2 1 4 0 0 Ext DC Input Fuse Fault The Ext DC Input fuse blows when powering on or running the 5071A The assumption here is that ONLY the dc fuse blows with the instrument operating normally from the ac line or internal standby battery for non Opt 048 1 Remove all power and disconnect A11P101 2 Replace the blown fuse 3 Reapply dc instrument power 4 Check the...

Page 89: ...specification If No Remove power replace A11 and retest charging current If Yes Replace both battery packs and retest operating time 2 1 5 2 0 A11 F1 Fuse Fault If the instrument will not operate from the internal batteries at all the fault could be fuse F1 on the A11 board Fuse F1 is in series with the batteries to protect them from catastrophic discharge if a short circuit occurs 1 Ensure that b...

Page 90: ...r and signal cable from A14 is seated in A6J3 6 Reapply power and wait until the LCD displays Fatal Error 7 Verify that the gain value displayed via the INFO GAIN menu selections is 14 4 8 Measure the following voltages Gnd to A6 TP5 voltage should be between 10 3 and 11 3 volts Gnd to A6 TP6 voltage should be between 11 3 and 10 3 volts QUESTION Are the voltages within the above specification If ...

Page 91: ...nd frequency of the logic signal at A6J2 pin 44 This is the twelfth pin from the right on the row of pins furthest away from the PCA board surface NOTE Use the 10 1 high impedance probe at the measurements with the input impedance of the oscilloscope and counter set to 1 MΩ Use dc coupling and set the trigger levels to 0 15 volts at the probe output The waveform should consist of TTL level pulses ...

Page 92: ...10 3 with the dip clip QUESTION Is the voltage between 4 75 and 5 25 If Yes Remove power replace A6 and retest If No Remove power replace A14 and retest 2 2 6 0 VFC Output Test 2 1 Use the high impedance probe frequency counter and oscilloscope to check frequency and amplitude of the logic signal at A6 U33 3 2 Verify that the waveform is TTL level pulse with a frequency between 219 and 231 kHz QUE...

Page 93: ...ree end to the spectrum analyzer with an SMA female female barrel and the Microwave Test cable for use at 9 GHz 6 Disconnect right hand CBT cable viewed from front from A2J2 7 Go to 2 3 2 0 2 3 2 0 9192 MHz Signal Spectrum Test 1 Set input attenuator on HP Agilent 8566 microwave spectrum analyzer for a maximum input level of 10 dBm Must be done before 2 2 Reconnect external ac or dc power 3 Verify...

Page 94: ...output to A9J5 QUESTION Is frequency 10 MHz 5 Hz If Yes Go to 2 3 4 0 If No Go to 3 9 1 1 A19 diagnostic tree 2 3 4 0 A10 Port 1 and 2 Amplitude Test 1 Program the rear panel output ports for 10 MHz 2 Use an oscilloscope to verify that both output provide a sine wave with an amplitude of at least 2 8 Vp p into 50 Ω Record results QUESTION Are both port amplitudes 2 8 Vp p If Yes Go to 2 3 5 0 If N...

Page 95: ...Frequency and Amplitude Tolerance Test 1 Disconnect A9P1 from A9J1 2 Connect A9J1 to the 50 Ω input of an oscilloscope Use a 50 Ω feedthrough at scope end of the cable if necessary 3 Verify presence of a sine wave with at least 6 0 Vp p amplitude 4 Disconnect A9J1 from the oscilloscope 5 Reprogram frequency counter to use 10 MHz external reference from 5071A output 6 Use the frequency counter to v...

Page 96: ... dBm 5 Reconnect coax to A5J2 QUESTION Did the signal meet the characteristics in step 5 If Yes Go to 2 3 8 2 If No Go to 3 5 3 0 A4 diagnostic tree 2 3 8 2 80 MHz Frequency Test 1 Disconnect coax from A5J1 2 Connect frequency counter to the free end of the coax not to A5J1 3 Verify the frequency as 80 MHz 0 1 Hz 4 Use an oscilloscope to verify that the sine wave voltage is at least 0 6 Vp p 5 Rec...

Page 97: ...splay units are Milliamperes The current value is set by the instrument to match the parameters of the CBT 7 Remove instrument power and replace the CFC jumper QUESTION Are the measured and indicated current magnitudes in agreement to within 0 2 mA If Yes The C Field system is working correctly If No Go to 2 4 2 0 2 4 2 0 C Field Current Source Test 1 Remove all power from the 5071A 2 Disconnect C...

Page 98: ...2 diagnostic tree A8 1 PPS module tree 3 3 3 0 A9 Frequency Multiplier module tree 4 3 4 1 0 A10 Output Frequency Distribution Amplifier module tree 5 3 5 1 0 A11 Power steering logic See section 2 Power supply diagnostic tree A12 Dc Dc Converter module See section 2 Power supply tree A13 Front panel assembly See section 1 Top level diagnostic tree A14 Signal Amplifier module See section 2 RF chai...

Page 99: ...A2 Hot Wire Ionizer tree 2 A2 Thermistor tree 3 A2 Mass Spectrometer tree 4 A2 Cesium Oven tree Each of the functional subsections is designed to isolate a fault to one of the following assemblies A2 CBT Controller A7 Interface A17 Cesium Beam Tube CBT Refer to the A2 CBT Controller Assembly pinouts shown below for A2J1 and A2J2 when any A2 tests require connection to either CBT or A2 J1 or J2 pin...

Page 100: ...le QUESTION Is the resistance between 0 1 and 0 25 Ω If Yes Go to 3 1 1 1 1 If No Recheck results and Ohmmeter then replace CBT 3 1 1 1 1 CBT Hot wire Resistance to Ground Test 1 Measure the resistance across pins 1 and 4 on the CBT cable QUESTION Is the resistance greater than 200 kΩ If Yes Go to 3 1 1 1 2 If No Recheck results and DMM then replace CBT 3 1 1 1 2 Hot Wire Monitor Test No Current 1...

Page 101: ... Ionizer voltage Terminal to instrument via RS 232C data communication required 3 Measure pins 1 and 37 reading should be between 20 0 and 21 0V 4 Measure pins 1 and 38 reading should be between 20 0 and 21 0V 5 Measure pins 3 and 37 reading should be between 20 0 and 21 0V 6 Measure pins 3 and 38 reading should be between 20 0 and 21 0V QUESTION Are all the readings within specified limits If Yes...

Page 102: ...e resistance measured between 200 and 250 kΩ If No Recheck results and DMM then replace CBT If Yes Go to 3 1 2 1 1 3 1 2 1 1 CBT Thermistor Ground Test 1 Use a DMM to measure the resistance between cable pins 7 and 11 QUESTION Is the resistance less than 1 Ω If No Recheck results and DMM then replace CBT If Yes Go to 3 1 2 1 2 3 1 2 1 2 Thermistor Monitor Test No Current 1 Remove instrument power ...

Page 103: ...2C data communication required QUESTION Is thermistor between 9 35 and 9 75 C If Yes Go to 3 1 2 1 4 If No Remove power replace A7 and retest 3 1 2 1 4 Thermistor Monitor Test 2 Current On 1 Place a 10 kΩ resistor between pins 3 and 7 on connector XA2P2 2 Use SCPI command syst print Terminal to instrument via RS 232C data communication required QUESTION Is thermistor between 9 35 and 9 75 C If Yes...

Page 104: ...check results and DMM then replace CBT 3 1 3 1 1 Mass Spectrometer Test Current Off 1 Remove instrument power 2 Replace A2 CBT Controller with long extender board 05071 60052 Do not insert A2 at this time 3 Reapply instrument power instrument will go to Fatal Error 4 Use SCPI command syst print Terminal to instrument via RS 232C data communication required QUESTION Is Mass spec between 0 5 and 0 5...

Page 105: ...or Test Current On 1 Place a 10 kΩ resistor between pins 3 and 37 on connector XA2P2 2 Use SCPI command syst print Terminal to instrument via RS 232C data communication required QUESTION Is Mass spec between 9 5 and 11V If Yes Remove power replace A2 and retest If No Remove power replace A7 and retest ...

Page 106: ...nce between 200 Ω and 250 k Ω If No Recheck results and DMM then replace CBT If Yes Go to 3 1 4 1 1 3 1 4 1 1 Cesium Oven to Ground Test 1 Use a DMM to measure the leakage resistance between cable pins 15 and 11 QUESTION Is the leakage resistance at least 10 k Ω If No Recheck results and DMM then replace CBT If Yes Go to 3 1 4 1 2 3 1 4 1 2 Cesium Oven Monitor Test Current Off 1 Remove instrument ...

Page 107: ...C data communication required QUESTION Is CBT Oven Err between 20 0 and 21 0C If Yes Go to 3 1 4 1 4 If No Remove power replace A7 and retest 3 1 4 1 4 Cesium Oven Monitor Test Current On 1 Place a 10 kΩ resistor Between pins 3 and 36 connector XA2P2 2 Use SCPI command syst print Terminal to instrument via RS 232C data communication required QUESTION Is CBT Oven Err between 20 0 and 21 0 C If Yes ...

Page 108: ...and 12V is between 12 and 12 5V to chassis QUESTION Are power supply voltages correct If Yes Go to 3 2 2 0 If No Go to 2 1 1 1 0 Power supply tree 3 2 2 0 80 MHz Signal Test 1 Disconnect coax cable from A5J1 2 Connect free end of cable to 50 Ω input of an oscilloscope If a 50 Ω input is absent use the high impedance input with a 50 Ω coaxial feedthrough terminator at the scope end of the coax 3 Ve...

Page 109: ...agnostic tree 3 2 3 0 A4 131 770 kHz Signal Test 1 Disconnect coax cable from A5J2 2 Connect free end of the cable to an HP Agilent 8566 spectrum analyzer or equivalent 3 Set the center frequency to 131 7 kHz and the span to 10 kHz 4 Verify presence of a signal at 131 770 kHz with at least 15 dBm amplitude 5 Reconnect cable to A5J2 QUESTION Does the spectrum analyzer show a signal at the correct f...

Page 110: ...6 spectrum analyzer or equiv to A5J101 2 Set center frequency to 87 368 MHz and span to 10 kHz 3 Verify presence of an 87 368 MHz 1 kHz signal with a 0 3 dBm amplitude QUESTION Does the spectrum analyzer show a signal at 87 368 MHz 1 kHz with amplitude 0 3 dBm If Yes A5 is nominally operational If No Remove power replace A5 and retest ...

Page 111: ...mplitude QUESTION Is the waveform as described in step 5 If Yes Go to 3 3 1 If No Go to 3 4 1 0 A9 Diagnostic tree 3 3 1 A8 1 MHz Output Signal Test 1 Remove instrument power 2 Reconnect cable marked A8P3 to A8J3 and reapply instrument power 3 Use the SO 16 dip clip and the oscilloscope with a high impedance probe to examine the wave form at A8 U41 2 and A8 U41 3 The correct waveform is a 1 MHz sq...

Page 112: ...t a time Remove power when changing assemblies QUESTION Did one or more replaced assemblies correct the problem If Yes Retain the replaced assembly and retest If No A1 may be defective contact Symmetricom for further assistance 3 3 2 Clock Increment Test 1 Set the Instrument LCD display to the CLOCK Set Menu 2 Verify that the time hh mm ss display increments at one second intervals QUESTION Does t...

Page 113: ...er if required 2 Use the oscilloscope with 50 Ω input termination to check for 20 microsecond pulses at a rate of 1 pulse per second at each of the three external 1 PPS output connectors 3 Verify that all 1 pps output levels are pulse low level less than 0 5 volts and pulse high level more than 3 0 volts Use a trigger level of 1 5 volts QUESTION Are all 1 pps outputs present as specified in step 2...

Page 114: ...nputs Go to 3 3 4 1 3 3 4 1 A8 Sync Fault 1 Remove instrument power and replace A8 2 Repeat procedure 3 3 4 QUESTION Does the LCD display Caught a sync pulse for both inputs If Yes Retain new A8 and retest If No Go to 3 3 5 3 3 5 A8 to Chassis Interconnect Test 1 Remove instrument power 2 Remove A8 from slot XA8 3 Carefully remove the five SMB cable connectors Note their locations first from J14 J...

Page 115: ...es correct If Yes Go to 3 4 2 0 If No Remove power replace A9 and retest 3 4 2 0 10 MHz Signal Test 1 Disconnect semi rigid cable from A9J5 2 Connect free end of the cable to a scope with 50 Ω input impedance If the scope doesn t have a 50 Ω input use the high impedance input with a 50 Ω coaxial feedthrough terminator installed at the scope end of the coax 3 Verify presence of 10 MHz undistorted s...

Page 116: ... 1 Connect A9J2 to the 50 Ω input of a scope using coax If a 50 Ω input is absent use the high impedance input with a 50 Ω coaxial feedthrough terminator at the scope end of the coax 2 Verify presence of an 80 MHz undistorted sine wave with at least 0 6 Vp p amplitude 3 Repeat steps 1 and 2 for A9J3 and A9J4 QUESTION Does the scope show an 80 MHz undistorted sine wave with at least 0 6 Vp p amplit...

Page 117: ...r supply voltages correct If Yes Go to 3 5 2 0 If No Remove power replace A10 and retest 3 5 2 0 A10 Module J5 80 MHz Input Test 1 Disconnect cable from A10J5 2 Connect free end of the cable to a scope with 50 Ω input impedance If a 50 Ω input is absent use the high impedance input with a 50 Ω coaxial feedthrough terminator at the scope end of the coax 3 Verify presence of an 80 MHz undistorted si...

Page 118: ...0 A9 diagnostic tree 3 5 3 0 A10 Module Output Port 1 Test 1 Connect port 1 on the rear panel to the 50 Ω input of a scope using coax If a 50 Ω input is absent use the high impedance input with a 50 Ω coaxial feedthrough terminator at the scope end of the coax 2 Verify the presence of a sine wave with an amplitude of at least 2 8 Vp p and a frequency of 5 or 10 MHz whichever has been selected see ...

Page 119: ... 1 output 5 MHz when it should be 10 MHz If Yes Go to 3 5 3 2 1 If No Go to 3 5 4 0 3 5 3 2 1 A10 Port 1 Frequency Selection Error Test 1 Check SEL A on A10 with a DMM 2 Verify that it is no greater than 2 volts QUESTION Is the SEL A voltage 2 or less If Yes Go to 3 5 3 2 2 If No Remove power replace A10 and retest 3 5 3 2 2 A10 SEL A Line Test 1 Remove instrument power 2 Unsolder white wire from ...

Page 120: ...put menu If Yes Go to 3 5 5 0 If No Go to 3 5 4 1 3 5 4 1 A10 Port 2 Frequency Error 10 not 5 MHz QUESTION Is the Port 2 output 10 MHz when it should be 5 MHz If Yes Go to 3 5 4 1 1 If No Go to 3 5 4 2 3 5 4 1 1 A10 Port 2 Frequency Selection Error Test 1 Connect a clip lead from SEL B on A10 to chassis ground 2 Recheck port 2 with scope 3 Verify presence of 5 MHz output 4 Remove clip lead QUESTIO...

Page 121: ... Verify that voltage is greater than 2 volts QUESTION Is voltage greater than 2 volts If Yes Remove power replace A7 and retest If No Remove power replace A10 and retest 3 5 5 0 A10 1 MHz Output Test 1 Connect the 1 MHz output connector on the rear panel to the 50 Ω input of a scope using coax If a 50 Ω input is absent use the high impedance input with a 50 Ω coaxial feedthrough terminator at the ...

Page 122: ...g coax If a 50 Ω input is absent use the high impedance input with a 50 Ω coaxial feedthrough terminator at the scope end of the coax 2 Verify presence of a 100 kHz undistorted sine wave with at least 2 8 Vp p amplitude QUESTION Does the scope show a 100 kHz undistorted sine wave with at least 2 8 Vp p amplitude If Yes A10 is nominally operational If No Remove power replace A10 and retest ...

Page 123: ...1 1 3 6 1 1 A18J3 Voltage Test 1 Disconnect cable from A18J3 2 Connect a DMM set for dc volts to A18J3 3 Verify the voltage present between 4 4 and 4 6V QUESTION Is the voltage between 4 4 and 4 6V If Yes Go to 3 6 1 2 If No Go to 3 8 1 0 A18 diagnostic tree 3 6 1 2 4 5V Cable Test 1 Remove instrument power 2 Unsolder wire from A15 4 5V terminal 3 Reapply instrument power 4 Check voltage on the wi...

Page 124: ...e analyzer show a 320 MHz signal with at least 18 dBm amplitude If Yes Go to 3 6 3 0 If No Go to 3 4 1 0 A9 diagnostic tree 3 6 3 0 A15J3 Signal Test 1 Disconnect coax cable from A18J4 2 Connect free end of the cable to a spectrum analyzer with 50 Ω input impedance 3 Verify the presence of a signal with frequency between 70 and 110 MHz and amplitude between 25 and 10 dBm 4 Reconnect cable to A18J4...

Page 125: ...with no sidebands present If Yes Go to 3 6 5 0 If No Go to 3 6 4 1 3 6 4 1 A15J5 CBT Cable Test 1 Remove four mounting nuts for A15 2 Slide A15 out far enough to create the clearance required to remove the semi rigid coax from A15J5 3 Remove the semi rigid coax from A15J5 4 Connect A15J5 to an HP Agilent 8566B microwave spectrum analyzer or equiv using an appropriate microwave coaxial test cable e...

Page 126: ... increase to at least 0 dBm If Yes Go to 3 6 6 0 If No Remove power replace A15 and retest 3 6 6 0 A15J2 Frequency Range Test 1 Disconnect cable from A15J2 2 Connect a 0 to 10 volt power supply to A15J2 3 Vary voltage from 0 to 10V while watching signal on spectrum analyzer connected to A15J5 4 Verify that a frequency of 9192 6 MHz can be obtained with a voltage between 2 and 8 Vdc QUESTION Can fr...

Page 127: ...signal generator output set for 10 MHz at 7 dBm to A9J5 replacing the 10 MHz input from A19 6 Power up and check that the instrument enters the warming up mode in about 10 seconds 3 7 1 1 Ion Pump High Voltage Supply Test 1 Power down the instrument 2 Wait at least one minute for A16 high voltage to bleed down 3 Disconnect the high voltage HV connector thick flexible wire on the right hand side of...

Page 128: ... voltage probe must have an input resistance of 1 GigaΩ If Yes Go to 3 7 1 3 If No Go to 3 7 1 3 1 3 7 1 3 Ion Pump Return Current Zero Test 1 Power down the instrument and wait one minute for the A16 module voltages to bleed down 2 Disconnect the Ion Pump supply cable from the high voltage probe and locate the plug well clear of other conductors 3 Re power the instrument wait 15 seconds and use t...

Page 129: ...lay 4 Re connect the A16 module to A1 at A1J12 QUESTION Was the displayed current between 0 0 and 1 0 microamps If Yes Remove power replace A16 and retest If No Go to 3 7 1 3 2 3 7 1 3 2 Ion Pump Current Monitor Diagnosis cont 1 Power down the instrument and remove the A2 module from the extender 2 Re power the instrument wait 15 seconds and use the INFO PUMP menu selection to display the Output o...

Page 130: ... output into the DMM Set voltage mode and at least 10 0 Volts range The input impedance of the DMM must equal that specified for the high voltage probe 5 Apply instrument power wait for the instrument to begin warming up and observe the voltage displayed by the DMM Multiply this voltage by the voltage division ratio of the probe and record results 6 Observe the voltage displayed on the LCD using t...

Page 131: ... the green LED A2DS1 is lit 4 Use the DMM to measure the current from A2U7 pin 3 to ground 5 Use the INFO E_mult Menu to display the program voltage of the Electron multiplier supply 6 Verify the ratio of displayed voltage to measured current as between 950 to 1050 volts per mA Ratio displayed voltage measured current QUESTION Is the ratio of displayed volts to measured mA correct If Yes A2 is del...

Page 132: ... 3 8 2 0 If No Go to 2 1 1 1 0 Power supply diagnostic tree 3 8 2 0 A5 87 368230 MHz Input Signal Test 1 Disconnect coax cable from A18J1 2 Connect free end of coax to the 50 Ω input of an oscilloscope If a 50 Ω input is absent use the high impedance input with a 50 Ω coaxial feedthrough terminator at the scope end of the coax 3 Verify the presence of an 87 MHz sine wave with at least 0 4 Vp p amp...

Page 133: ...o to A5 diagnostic tree 3 8 3 0 A15 70 110 MHz Input Test 1 Disconnect coax cable from A18J4 2 Connect free end of the cable to the 50 Ω input of a spectrum analyzer 3 Verify presence of a signal with frequency between 70 and 110 MHz and amplitude between 25 and 10 dBm 4 Reconnect cable to A18J4 QUESTION Does the spectrum analyzer verify the signal in step 3 If Yes Go to 3 8 4 0 If No Go to 3 8 3 ...

Page 134: ... of 320 MHz and amplitude of at least 18 dBm 4 Reconnect cable to A15J4 QUESTION Does the analyzer show a signal with frequency of 320 MHz and amplitude of at least 18 dBm If Yes Remove power replace A15 and retest If No Go to 3 4 1 0 A9 diagnostic tree 3 8 3 3 A18J3 DC Voltage Test 1 Disconnect cable from A18J3 2 Use a DMM to carefully check the dc voltage of the A18J3 center pin 3 Verify that th...

Page 135: ...minal with a scope 2 Verify that the average voltage is less than 0 05 Vdc QUESTION Is the average voltage less than 0 05 Vdc If Yes Go to A15 diagnostic tree If No Remove power replace A18 and retest 3 8 4 2 A18 Average Mon Voltage Test 1 Measure dc voltage on the A18 mon terminal with a scope 2 Verify that the average voltage is more than 0 45 Vdc QUESTION Is the average voltage more than 0 45 V...

Page 136: ...er down the instrument and remove A6 2 Check the continuity of fuses A6 F3 F4 F5 2 5 Ω or less and replace as required 3 Mount A6 in the instrument with the short extender card 05071 60051 4 Disconnect A19 from A1 at A1J11 and CBT cable from A2J2 5 Disconnect the semi rigid cable from A19 to A9J5 6 Connect the signal generator output set to provide 10 MHz at 7 dBm to A9J5 7 Apply power to the inst...

Page 137: ...volts QUESTION Are the power supply voltages correct If Yes Go to 3 9 1 3 If No Go to 3 9 1 2 1 3 9 1 2 1 A19 Power Fault 1 Remove instrument power 2 Replace A6 3 Reapply power Wait until LCD displays Warming up 4 Use the CONFIG Mode menu to go to STANDBY 5 Measure the A19 supply voltages with a DMM at test points TP9 TP8 and TP7 on A6 to verify compliance as follows TP9 12 v nominal more than 11 ...

Page 138: ...Record the position of the jumper connecting the left hand row of pins of A6 J4 with the right hand The jumper positions number 1 through 9 beginning at the bottom 2 Use the INFO Ctrl menu to determine the EFC control voltage as a percentage between 100 and 100 3 Calculate the expected EFC control voltage using the formula Control voltage 1 25 5 Pos Jmpr 0 03308 Ctrl For example if the jumper is i...

Page 139: ...he value of the A19 VCXO oven monitor using the INFO Ovens menu 4 Verify that the voltage is now be between 10 0 and 5 0 volts indicating that the oscillator oven has warmed up QUESTION Does the A19 oven warm up in 10 minutes or less If Yes Go to 3 9 1 6 If No Remove power replace A19 and retest 3 9 1 6 A19 Signal Amplitude Test 1 Disconnect the semi rigid cable from A9J5 2 Use the adapter cable t...

Page 140: ...ference oscillator chain has checked out correctly If No Go to 3 9 1 8 3 9 1 8 A19 VCXO Set Point Adjustment The following procedure attempts to adjust the VCXO set point It should be carried out if the A19 appears to have aged out of tolerance or if a new A19 has been installed 1 Remove the cover plate from the left side of the instrument as seen from the front 2 Observe the frequency output of A...

Page 141: ...ized microwave probe signal to the hyperfine resonance in the ground state of the cesium atom This resonance is the basis for the internationally accepted unit of time In operation the frequency of a nominal 10 MHz crystal oscillator is multiplied by the correct fixed rational number frequency synthesis process to achieve the cesium resonance frequency at 9 192 GHz This synthesized frequency is co...

Page 142: ...generation and 6 AC DC power supply and distribution Functional Block Descriptions This section explains how assemblies and modules work together in groups see Figure 3 2 to provide the functions and signals described in the simplified functional description Additionally signal path tables are included to provide specific signal path and cabling information useful for ensuring or re establishing c...

Page 143: ... in 1013 of the internationally accepted definition of frequency The organization of the six blocks within the instrument is shown in Figure 3 1 They are 1 Instrument control A3 A7 A13 and Instrument bus I bus 2 Reference oscillator RF chain A4 A5 A9 A15 A18 and A19 3 Cesium Beam tube A2 A16 and A17 4 Analog signal chain A6 and A14 5 Input output A8 and A10 6 Power distribution A1 A11 A12 LF1 T1 a...

Page 144: ...e reference oscillator Accordingly the block also provides amplitude and phase coherent frequency modulation applied to the microwave probe signal which is then fed to the Cesium Beam Tube CBT Cesium Beam Tube Block The Cesium Beam tube block operates by matching the frequency of the microwave probe signal with the hyperfine resonance of cesium atoms The comparison occurs in the CBT This resonance...

Page 145: ...h signals in the RF chain The I O block receives two low noise 80 MHz signals from the reference oscillator RF chain block These 80 MHz signals are used to create the instrument s 1PPS and sine wave outputs When the microwave probe signal is at correct frequency and amplitude the I O block will synthesize the exact nominal output frequencies The block also receives a front or rear panel Sync input...

Page 146: ...t Control Block A3 Microprocessor A7 Interface A13 Front Panel Instrument bus I bus Reference Oscillator RF chain Block A19 Reference Oscillator VCXO A9 Frequency Multiplier A5 87 MHz PLL A4 Digital Synthesizer A18 9 2 GHz PLL A15 9 2 GHz Microwave Generator Module Cesium Beam Tube Block A2 CBT Controller A16 High Voltage Supply Module A17 CBT Cesium Beam Tube Analog Signal Chain Block A14 Signal ...

Page 147: ...3 Theory of Operation Functional Block Descriptions 131 Figure 3 2 5071A Overall Block Diagram ...

Page 148: ...3 Theory of Operation Functional Block Descriptions 132 Figure 3 2 5071A Overall Block Diagram Continued ...

Page 149: ...e test bench and rack mount front panel user interface operation while the rear panel RS 232C port and status output provide the interface hardware for remote operation with the on board SCPI command set The VFC and VFC clock lines go to A6 providing a path for specific frequency count data that arrives from the analog signal chain block The Strobe output is routed to A4 A6 A7 and is used synchron...

Page 150: ...ument Control Block Interconnections Source Module or Assembly From Path Connectors Pin in italics Signal Name To Path Connectors Pin in italics Destination Module or Assembly A3 XA3J1 60 61 62 RS 232C 3 A1J6 Rear Panel A3 XA3J2 14 46 Strobe 2 RTDS XA4J2 14 46 XA6J2 14 46 XA7J2 14 46 A4 A6 A7 A11 A11P102 Power Status 4 via A1J3 XA3J1 26 27 28 58 A3 A6 XA6J2 14 44 VFC 2 VFCP XA3J2 12 44 A3 A3 XA3J2...

Page 151: ...n The firmware then steps through various levels of RF attenuation to obtain optimum power for the microwave probe signal Next the electron multiplier is adjusted to obtain the desired CBT output current After these settings have been logged in memory the C field is set to the proper value When these adjustments are complete the operating mode changes automatically to Normal Operation the green co...

Page 152: ...coding information Warning Mode The warning mode occurs when the health monitor detects a possible problem or internal standby battery operation The instrument can still run as a frequency standard but the user is warned of a possible problem or future problem The Continuous Operation LED flashes and the Warning LED is lit After a transient warning the instrument can return to normal operation by ...

Page 153: ... MHz signal sent to A8 1 PPS assembly b an 80 MHz signal sent to A10 output frequency distribution amplifier module c an 80 MHz signal sent to A5 87 MHz PLL module and d a 320 MHz signal sent to A15 9 2 GHz microwave generator module A4 receives command input via its I bus connection directing its internal circuits to generate the appropriate agile sine wave output centered around 131 77138 kHz Th...

Page 154: ...A19 A19 A19J1 10 MHz Reference A9J5 A9 A9 A9J4 80 MHz A8J3 A8 A9 A9J2 80 MHz A10J5 A10 A9 A9J1 320 MHz A15J4 A15 A9 A9J3 80 MHz A5J1 A5 A4 A4J3 131 77 kHz Frequency modulated A5J2 A5 A5 A5J101 87 3668 MHz A18J1 A18 A18 A18J2 Tuning Voltage A15J2 A15 A18 A18J3 4 5 V A15 4 5 A15 A15 A15J3 87 3668 MHz PLL Feedback A18J4 A18 A7 A1J19 Amplitude Modulation IAT A15J1 A15 A15 A15J5 μWave Probe Signal 9 GH...

Page 155: ...supply at a voltage of 900 to 2500 volts dc The set point of this supply is determined by a control current generated by a D to A converter on A2 The Electron Multiplier supply is disabled whenever the instrument is the Fatal Error or Standby modes A17 has eight inputs and one primary output The ion pump electron multiplier C field control Thermistor signal lines mass spectrometer control hot wire...

Page 156: ... 3 A1J12 A16 A16 Long White HV lead Ion Pump Right hand CBT HV socket A17 A16 Short White HV lead Electron Multiplier Left hand CBT HV socket A17 A7 XA7J2 10 C Field Control CFC XA2J2 10 A2 A2 A2J2 C Field Control A17P3 A17 A2 A2J2 Thermistor A17P3 A17 A2 A2J2 Mass Spectrometer A17P3 A17 A2 A2J1 Hot Wire Ionizer A17P4 A17 A2 A2J2 Cesium Oven A17P3 A17 A15 A15J5 μ Wave Probe Signal 9 GHz A17 Adapte...

Page 157: ...ifier with a frequency response of dc 900 Hz The push pull output A14 Vout of the amplifier is coupled to the differential signal channel input of A6 which also supplies it with power The single ended to differential transimpedance of A14 is 50 MΩ The input stage of A6 feeds a programmable amplifier gain set by A3 via I bus The amplified CBT signal is then converted to a chain of pulses by a linea...

Page 158: ... in italics Signal Name To Path Connectors Pin in italics Destination Module or Assembly A17 A17P1 CBT Output A14J1 A14 A14 A14J2 A14 Vout A6J3 A6 A6 XA6J2 12 44 VFC 2 VFCP XA3J2 12 44 A3 A3 XA3J2 13 45 VFCclock 2 0 5 MHz XA6J2 13 45 A6 A6 A6J5 EFC 2 EFC REFC A19J11 39 40 A19 A6 XA6J2 39 40 A19 Power 2 VCXO A1J11 A19 A3 XA3J1 2 I bus Instrument Bus XA6J1 2 A6 ...

Page 159: ...s 1 pps outputs to external events and systems Table 3 5 Input Output Block Interconnections Source Mdl or Assy From Path Connectors Signal Name Connector Pin in italics To Path Connectors Destination Mdl or Assy Sync Input Front Panel A1J17 Sync Input XA8J2 10 11 12 A8 Sync Input Rear Panel A1J15 Sync Input XA8J2 42 43 44 A8 A9 A9J4 80 MHz Input A8J3 A8 A8 XA8J2 16 48 1 MHz Internal Bus Clock XAn...

Page 160: ...m catastrophic discharge none for Opt 048 AC power enters the instrument at LF1 line filter cable assembly providing initial filtering fuse protection and line voltage selection The LF1 cable assembly connects directly to the primary windings of T1 toroidal power transformer stepping down the selected line voltage to an approximate 28 Vrms 37 Vrms for opt 048 ac voltage The T1 secondary output is ...

Page 161: ...wer 40 58 Vdc on Opt 048 filtered on A1 A1J4 A11J101 A11 A1 A1J4 32 38 Volts DC 45 51 Vdc for Opt 048 rectified and filtered on A1 A1P4 A11P101 A11 A11 A11P101 Steered DC Power 22 42 V 40 58 Vdc on Opt 048 A1J4 A1 A1 A1J4 Steered DC Power 22 42 V 40 58 Vdc on Opt 048 low pass filtered on A1 A1J2 A12P2 A12 A12 A12P2 12 3 VOut 12 3 VReturn 12 3 VOut 12 3 VReturn 5 45 VOut 5 45 VReturn A1J2 A1 P O B1...

Page 162: ...ar circuit comprised of silicon controlled rectifier SCR A1CR1 zener diode A1VR1 resistors A1R1 through A1R3 A1R5 A1R6 and capacitor A1C1 This circuit not only protects the components within the Overvoltage Protection circuit but also the dc dc converter integrated circuits ICs A12U1 through A12U3 on A12 Dc Dc Power Converter Module rated at a maximum input voltage of 56 Vdc 72 Vdc for Opt 048 Whe...

Page 163: ...t from an external dc source 22 to 42V 40 58 Vdc on Opt 048 The dc voltage is then routed to a filter consisting of A1L1 and A1C2 before being sent to A11 Power Steering Logic Assembly via connector A1J4 Capacitor C2 is rated at 80V 100V for Opt 048 as the maximum allowable input voltage is 42V 58V for Opt 048 Diode A1CR2 prevents any damage to the instrument if the external dc input source is rev...

Page 164: ...3 Theory of Operation Functional Block Descriptions 148 Figure 3 3 A1 Power Supply Distribution Schematic Diagram ...

Page 165: ...3 Theory of Operation Functional Block Descriptions 149 Figure 3 3 A1 Power Supply Distribution Schematic Diagram Continued ...

Page 166: ...3 Theory of Operation Functional Block Descriptions 150 Figure 3 4 A1 Slot Module Interconnect Diagram ...

Page 167: ...3 Theory of Operation Functional Block Descriptions 151 Figure 3 4 A1 Slot Module Interconnect Diagram continued This schematic also applies for Opt 048 ...

Page 168: ...3 Theory of Operation Functional Block Descriptions 152 Figure 3 5 Power Supply Block Diagram ...

Page 169: ...ctional Block Descriptions 153 Option 048 Schematic Block Diagrams The following figures 3 6 to 3 8 are the corresponding schematics for an option 048 instrument Figure 3 6 Opt 048 A1 Power Supply Distribution Schematic Diagram ...

Page 170: ...3 Theory of Operation Functional Block Descriptions 154 Figure 3 6 Opt 048 A1 Power Supply Distribution Schematic Diagram Continued ...

Page 171: ...3 Theory of Operation Functional Block Descriptions 155 Figure 3 7 Opt 048 A1 Slot Module Interconnect Diagram ...

Page 172: ...3 Theory of Operation Functional Block Descriptions 156 Figure 3 8 Opt 048 Power Supply Block Diagram ...

Page 173: ......

Page 174: ...vides ac line noise and spike protection fuse protection and line voltage selection The assembly mounts to the rear bulkhead of the instrument chassis and connects directly to the toroidal power transformer T1 T1 Toroidal Power Transformer The toroidal power transformer provides the required ac step down capability to supply the A12 module with its specified input voltage after appropriate rectifi...

Page 175: ...3 Theory of Operation Functional Block Descriptions 159 Figure 3 9 A1 Component Locator Diagram ...

Page 176: ...ned on Damage to components can occur Figures 2 1 and 5 1 are provided to complement the removal and replacement procedures Refer to Chapter 5 Replaceable Parts for the part number of assemblies and modules Tools Required The following tools are required for the removal and replacement procedures Hand TORX 8 screwdriver and bit T8 Hand TORX 10 screwdriver and bit T10 Hand TORX 15 screwdriver T15 H...

Page 177: ...URCES CAUTION Always follow ESD precautions to prevent static damage to assemblies modules and any other internal components Refer to Figure 5 1 when performing the following steps 1 Ensure that ALL external and internal power is OFF 2 Remove the four rear feet from the instrument before attempting to remove the top or side instrument covers with a TORX T10 driver Refer to steps 4 and 5 below to r...

Page 178: ...amaging the mating connectors Ensure that the extractors are flush To Remove Any Other PC Boards Use the extractor tabs at each end simultaneously to draw the PC board out of its mating connectors Install a new PC board by first aligning the PC board in the slot and then use only the extractors to press into place This avoids damaging the mating connectors Ensure that the extractors are flush To R...

Page 179: ...d A5 if its removal is not required 5 Lift A9 and A18 out and set aside Install new functional unit if either or both is being replaced at this time 6 If A5 is being replaced at this time remove the 2 round head screws holding it to the right rear side chassis lift it out and install a new functional unit 7 Remove the ten flat head screws that hold A10 to the chassis from the rear panel located ar...

Page 180: ...do not remove 2 screws that hold the line filter cable assembly to the rear panel to gain clearance for A12 removal 6 Clip the A12 cable assembly wire tie 7 Disconnect A12 power cable from A1 8 Push A12 forward from the rear and up from the bottom alternately back and forth until the unit is free 9 Lift A12 out from the chassis and set aside and install a new functional unit 10 If A16 requires rep...

Page 181: ...are removed 2 Open the front panel door 3 Carefully remove the 9 16 dress nuts that hold the 1 pps Output and Sync Input BNC connectors to the inside front panel 4 Close the front door securely 5 Remove trim strips from sides of the front panel frame 6 Remove the four screws that hold the front panel assembly to the left and right side chassis members 7 Carefully disconnect the front panel ribbon ...

Page 182: ...tical aluminum CBT bulkhead 8 Carefully slide the A19 A14 bracket and units upward until the A14 connections are about even with the top of the CBT bulkhead 9 While holding the A19 A14 units in this position carefully disconnect the A14 SMB CBT input cable connector and unplug the 05071 60243 six wire power and output connector from A14 10 Place the A19 A14 modules bracket on a clean flat work sur...

Page 183: ...ed to J2 J3 J4 and 4 5Vdc on A15 6 Carefully slide A15 out far enough to gain the clearance required to remove all SMA connectors 7 Reverse the order of steps used to install a new functional module To Remove A16 High Voltage Supply Module 1 Refer to the A12 removal and replacement procedure near the beginning of this section 2 Use the appropriate steps to remove and replace A16 WARNING HAZARDOUS ...

Page 184: ...port and configure for serial data communication to monitor and record the power up sequence after installation is complete 2 Set 5071A serial communications parameters so that they match the printer terminal connected 3 Set 5071A Diagnostic Log mode to Service 4 Save the settings in 5071A memory using the Store function 5 Check that communication works by selecting Info Print and pressing Enter 6...

Page 185: ...ter Continue to loosen the SMA nut with your fingers until it is completely disconnected The Microwave Adapter is a small metal device that is part of the CBT towards the rear near the tube center 8 Record the position of the two High Voltage cables for later reassembly 9 Unscrew the two High Voltage connectors using only your fingers Do not use any pliers or wrenches as these can crack the plasti...

Page 186: ...re ensures that there will be no RF leakage at the SMA connection after final torque has been applied 19 If a settable wrench is not available use both a standard 5 16 and a 1 4 open end wrench and do your best to assure a tight connection A good rule of thumb is to make the connection as tight as it was when initially removed 20 Connect the two multiple pin connectors to the A2 CBT Controller ass...

Page 187: ...ion captured 2 Connect power to the instrument noting the time 3 If the message Cs Oven is Up does not appear within 25 minutes there may be a problem with the connections to the A2 CBT Controller assembly Remove all power disconnect the internal standby battery and re check your work 4 When the message Operating Normally appears the instrument is operating No further adjustments are needed ...

Page 188: ...accordance with local environmental regulations Contact your nearest regional office of environmental health service for guidance Direct Shipment to the Symmetricom Factory The following steps describe how to package and ship a defective 5071A cesium beam tube back to the Symmetricom factory 1 If you do not have appropriate CBT packaging materials you can obtain a CBT Packaging Kit from Symmetrico...

Page 189: ...e Oscillator Module 173 To Remove A19 Reference Oscillator Module 1 Refer to the A14 removal and replacement procedure near the middle of this section 2 Use the appropriate steps to remove and replace A19 3 Reverse the order of steps used to install a new functional module ...

Page 190: ...mm output options How To Order A Part Symmetricom wants to keep your parts ordering process as simple and efficient as possible To order parts perform the following steps 1 Identify the part and the quantity you want 2 Determine the ordering method to be used and contact Symmetricom Parts Identification To identify the part s you want first refer to the exploded view in Figure 5 1 at the back of t...

Page 191: ...der A Part 175 Contacting Symmetricom When ordering parts contact your Symmetricom sales representative or distributor They can assist in placing your order To arrange for service and repair contact Symmetricom Customer Assistance ...

Page 192: ...gic Std A11 05071 60033 Power Steering Logic 48VDC Version A12 05071 60212 DC DC Power Converter Module A12 05071 60279 DC DC Power Converter 48VDC Version A13 05071 60213 Front Panel Module A14 05071 60214 Signal Amplifier Module A15 05071 60215 9 2 GHz Microwave Generator Module A16 05071 60216 High Voltage Supply Module A17 10890A Cesium Beam Tube Long Life A17 10891A Cesium Beam Tube High Perf...

Page 193: ...ndle 0510 0182 Door Latch 1251 0126 External DC Mating Connector 5 pin Circular 1400 3290 Rack Slide Hardware Kit 1494 0458 Rack Slide One pair Must also order P N 1400 3290 59991 91102 Shipping Kit for 10890A 10891A CBT 59991 91105 Shipping Kit for 5071A 10890A Standard Long Life CBT 12 year warranty 10891A High Performance CBT 5 year warranty 05071 67006 Firmware Kit ...

Page 194: ...5 Replaceable Parts How To Order A Part 178 ...

Page 195: ...ions Introduction The information in this chapter is identical to that found in the 5071A Operating and Programming manual P N 05071 90041 Please refer to Chapter 6 in that document for any references to specifications in this manual ...

Page 196: ...m com support index aspx or by calling one of the above Customer Assistance Center numbers When calling the worldwide or USA based number select Option 1 at the first prompt Telecom Solutions Division customers should then select Option 1 Timing Test and Measurement Division customers should then select Option 2 Technical Support personnel are available by phone 24 hours a day 7 days a week throug...

Page 197: ......

Page 198: ...ility 21 test 3 Stability frequency domain 21 test 3 stability time domain 21 Component locator diagram 159 Configuration RS 232C cabling setups 10 Contacting Hewlett Packard 175 Continuous operation light 5 Corrective maintenance 25 Dc power 144 Delayed failures warnings and messages 44 Depth of modulation 63 Diagnostic trees and procedures Diagnostic troubleshooting trees and procedures 33 Disas...

Page 199: ...r module 166 A15 9 2 GHz microwave generator module 167 A16 high voltage supply module 167 A17 CBT assembly 168 A17 CBT replacement operation verification 171 A19 reference oscillator module 173 covers top bottom and side 161 Repair strategy HP 5071A xiii Repair tools 160 Replacing assemblies 160 Returning the instrument to HP 25 RS 232 data communication 84 85 86 87 88 89 90 91 RS 232 verificatio...

Page 200: ...ent zero test 112 A16 preliminary set up 111 A16 CBT excess ion pump current test 52 A18 mon voltage test 119 A18 average mon voltage test 119 A18 mon signal ac content test 119 A18 power check 116 A18 A15 4 5V test 118 A18 A15 320 MHz input test 118 A18 A15 70 110 MHz input test 117 A18 A15J3 and A18J4 cable test 117 A18 A18J3 dc voltage test 118 A18 A18J3 to A15 4 5V cable test 118 A18 A18J4 sig...

Page 201: ...lation 63 diagnostic tree organization 34 diagnostic trees and procedures 33 digital supply voltage check 38 disassembly and reassembly 28 electrostatic discharge 28 equipment required 2 example error code interpretation 50 exchange part availability 31 ext dc input fuse fault 72 fatal error interpretation 45 first power on 37 functional group diagnostic trees 66 ground continuity test 29 HP 5071A...

Page 202: ...tools special 5 top level diagnostic tree 37 top level diagnostic tree organization 35 tube PROM test 46 VCXO control value 43 63 visual inspection 29 warm up and fatal error diagnostic tree 49 warm up error interpretation 51 warning message diagnostic tree 57 warning message interpretation 57 VCXO control value 43 Visual inspection 29 Warnings delayed 44 ...

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