Theory of Operation, Ahp33f.eps | Fluke 5720A instruction

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Fluke 5720A service manual Theory of Operation, 2. Analog Section Block Diagram, Part, ahp33f.eps

Contents

Multi-Function Calibrator Service Manual5700A/5720A Series 5/94 LIMITED WARRANTY & LIMITATION OF LIABILITY Bescheinigung des Herstellers/Importeurs Interference InformationDeclaration of the Manufacturer or Importer Page Terms in this Manual OPERATOR SAFETY SUMMARYHIGH VOLTAGE LETHAL VOLTAGE Use the Proper Fuse Symbols Marked on EquipmentPower Source Use the Proper Power Cord Use Care When Servicing With Power On SERVICING SAFETY SUMMARYFOR QUALIFIED SERVICE PERSONNEL ONLY Do Not Service Alone Never Accept Ordinary and General Tests for Death FIRST AID FOR ELECTRIC SHOCKFree the Victim From the Live Conductor Get Help Page Table of ContentsIntroduction and Specifications Title Theory of Operation 5700A/5720A Series ±PA Supplies Digital Control How the DAC is Used in Calibration Calibration Procedure Calibration and VerificationOhms Cal Assembly A9 Using Remote Commands Reserved for Servicing MaintenanceTroubleshooting Rear Panel Assembly Access List of Replaceable Parts Schematic Diagrams viii List of Tables Unregulated Supplies from the Filter Assembly A13A1 Oscillator Wideband SMD PCA A16A1 Power Amplifier Digital Control SIP PCATest Record for Flatness Check of the AC 2 mV Range A11A2 DAC Buffered Reference SIP PCA 5700A/5720A Series List of Figures Ohms Main Assembly Simplified Schematic A15 High Voltage/High Current PCA Power Amplifier with Calibrator Set to 22V at 1 kHz 5700A/5720A Series Chapter Introduction and Specifications 5700A/5720A Series II Calibrator Service Manual 1-1. Introduction 1-3. About this Manual 1-4. How to Use this Manual1-2. Contacting Fluke ∙ 5700A/5720A Series II Operator Reference Guide PN 1-5. Additional Instruction Manuals1-6. Wideband AC Voltage Module Option 5700A-03 ∙ 5700A/5720A Series II Getting Started Manual PN 1-8. 5725A Amplifier 1-9. Support Equipment and Services1-7. Auxiliary Amplifiers 1-13. Wideband AC Module Option 5700A-03 Calibration Support 1-11. 732B-200 Direct Volt Maintenance Program U.S.A. Only1-10. 732B Direct Voltage Reference Standard 1-12. 742A Series Resistance Standards 1-15. The Components of the 5700A/5720A Series II Calibrator 1-14. Service Centers Calibrating the 5700A/5720A Series II Calibrator 1-16. Calibrating the 5700A/5720A Series II Calibrator 1-18. Establishing Traceability 1-17. The Calibration Process 1-19. Calibration Reports 1-20. Calibration Check1-21. Developing a Performance History 1-22. Range Calibration 1-24. Specifications1-25. Specification Confidence Levels 1-26. Using Absolute and Relative Uncertainty Specifications Specifications 1-27. Using Secondary Performance Specifications 95% Confidence Level 1-28. DC Voltage Specifications5720A 99 % Confidence Level 95 % Confidence Level DC Voltage Specifications5700A 99 % Confidence Level Overshoot 5 % Common mode rejection 140 dB, DC to 400 Hz AC Voltage Specifications 1-29. AC Voltage Specifications See Volt-Hertz capability in Figure 90 Days 99 % Conf idence Level± 5 C from calibration temperature 95% Confidence Level ±ppm output + mV ± ppm output + μV0-10 C and dBm reference 600 Ω 5725A AmplifierFigure 1-2. Volt-Hertz Capability 99% Confidence Level 1-30. Resistance SpecificationsResistance Specifications 5700A active ±1 C NoteCharacterized compensation I IL Table 1-13. Current Derating Factors 5720A 95% 1-31. DC Current SpecificationsDC Current Specifications 5720A 99% 5700A Overshoot 5 % 1-32. AC Current Specifications AC Current Specifications 99 % Confidence Level 95 % Confidence Level maximum load for full accuracy Temperature Coefficient Note± ppm output + nA V rms 1-35 1-33. Wideband AC Voltage Option 5700-03 SpecificationsWideband AC Voltage Option 5700-03 Specifications Table 1-22. Wideband AC Voltage Option 5700-03 Specifications Size 1-34. General SpecificationsGuard isolation 20 5205A 220V - 1100 V ac, 0 V - 1100 V dc Overshoot 10 % 1-35. Auxiliary Amplifier SpecificationsAuxiliary Amplifier Specifications 5220A AC Current, 180-day specifications 5700A/5720A Series II Calibrator Theory of Operation 2-36 Theory of Operation 2-155 2-4. Hybrid Reference Amplifiers 2-1. Introduction2-2. Calibrator Overview 2-3. Internal References 2-6. Digital-to-Analog Converter DAC 2-7. Digital Section Overview2-8. Analog Section Overview ahp003f.eps Figure 2-1. Digital Section Block DiagramAnalog Section Overview 2-10. DC Voltage Functional Description 2-9. Functional Description Presented by Output Function ahp33f.eps Figure 2-2. Analog Section Block Diagram, Part 5700/5720A Series II Calibrator Figure 2-3. Analog Section Block Diagram, Part 2-11. AC Voltage Functional Description 2-14. AC Current Functional Description 2-12. Wideband AC V Functional Description Option2-13. DC Current Functional Description 2-15. Ohms Functional Description 2-17. Digital Motherboard Assembly A42-16. System Interconnect Detailed Circuit Description 2-19. Analog Motherboard Assembly A3 2-18. Transformer Assembly A22 ahp35f.eps Functional Description Presented by 0utput FunctionFigure 2-4. System Interconnections Figure 2-4. System Interconnections cont Connected to Assembly Table 2-1. Analog Motherboard ConnectorsMotherboard Connector 2-23. Digital Section Detailed Circuit Description 2-21. Rear Panel Assembly A212-22. Filter PA Supply Assembly A18 2-24. Digital Power Supply Assembly A19 Digital Section Detailed Circuit Description 2-25. +5V Power Supply2-26. ±12V Power Supplies 2-27. +35V Power Supply 2-29. +35V and +75V Shut-Down Circuit 2-28. +75V Power Supply 2-32. Clock Generation 2-30. CPU Central Processing Unit Assembly A202-31. Power-Up and Reset Circuit ahp004f.eps Figure 2-5. CPU Assembly Block Diagram Function Table 2-3. CPU Acronym Glossary Chip Select 2-33. Watchdog Timer2-34. Address Decoding and DTACK Data Acknowledge Table 2-4. CPU Memory Map 2-38. ROM Read-Only Memory 2-37. RAM Random-Access Memory2-35. Interrupt Controller 2-36. Glue Logic 2-41. Clock/Calendar Circuit 2-39. Electrically-Erasable Programmable Read-Only Memory EEPROM2-40. DUART Dual Universal Asynchronous Receiver/transmitter Circuit 2-45. Fan Monitor 2-42. Clock Filter Circuit2-43. CPU to Rear Panel Interface 2-44. CPU to Front Panel Interface 2-49. Decoding and Timing Circuitry 2-46. Front Panel Assembly A22-47. Clock Regeneration Circuitry 2-48. Refresh Failure Detect Circuitry êêêêêêê 2-50. Control Display Circuitry 2-51. Output Display Circuitry 2-53. Knob Encoder Circuitry 2-52. Keyboard Scanner Circuitry 2-54. Led Circuitry 2-55. Keyboard Assembly A1 2-57. Filter/PA Supply A18, Low-voltage Filter/Regulator Section 2-56. Analog Section Detailed Circuit Description 2-61. Triac Circuit 2-58. Unregulated OSC Supplies2-59. Unregulated LH Supplies 2-60. Unregulated S Supplies 2-66. ±PA Supplies Digital Control 2-65. Filter/PA Supply A18, Power Amplifier Output Supply Section2-64. FR2 Supplies ahp005f.eps Figure 2-6. Power Amplifier Output Supply Simplified Schematic ∙ PA CT is the center tap 2-67. ±250V and ±500V Supplies2-68. +PA and -PA Supplies 2-69. ±PA Supply Current Limit 2-72. Regulated OSC Supplies 2-70. Regulator/Guard Crossing Assembly A172-71. Voltage Regulator Circuitry +15V +5.975V +5.1V +44.15V +17.000V -17.000V +30.96V +30.96V 2-73. Regulated LH Supplies2-74. Regulated S Supplies +15 OSC -15 OSC +5RLH +5LH -5LH +44S -44S +17S -17S 15S +30FR1 +30FR2 2-76. FR2 Supply 2-75. FR1 Supply 2-78. Inguard CPU Memory Map 2-79. Inguard Memory Configuration2-77. Guarded Digital Control Circuitry 2-83. Break Detection 2-81. Inguard Watchdog Timer2-82. Power-Up and Reset Circuitry 2-80. Inguard Clock Circuit 2-86. Inguard CPU Interrupts 2-87. Switch Matrix Assembly A82-85. Interface to Guarded Digital Bus 2-88. Switch Matrix Digital Control System Interconnection Detailed Circuit Description Figure 2-7. Switch Matrix Assembly Simplified Schematic 3. Apply 7V to the relay coils by setting PC5 high 2-89. Switch Matrix Operation 11V DC and 22V DC Ranges ahp006f.eps Figure 2-8. Switch Matrix Configuration for 11V DC and 22V DC Ranges 2-91. Switch Matrix Operation 220V AC and DC Ranges 2-90. Switch Matrix Operation 2.2V AC and 22V AC Ranges ahp007f.eps Figure 2-9. Switch Matrix Configuration for 2.2V and 22V AC Ranges ahp008f.eps Figure 2-10. Switch Matrix Configuration for 220V DC and AC Ranges 2-92. Switch Matrix Operation 2.2V DC Range ahp009f.eps Figure 2-11. Switch Matrix Configuration for 2.2V DC Range To calibrate the offset 2-94. Switch Matrix Operation 220 mV DC Range2-93. Calibration of the 2.2V Range ahp010f.eps Figure 2-12. Calibration of the 2.2V DC Range ahp011f.eps Figure 2-13. Switch Matrix Configuration for 220 mV DC Range 2-97. Calibration of the mV Ranges 2-95. Switch Matrix Operation 220 mV AC Range2-96. Switch Matrix Operation 2.2 mV and 22 mV AC Ranges ahp012f.eps Figure 2-14. V AC, 2.2 mV AC, and 22 mV AC Range ahp013f.eps Figure 2-15. Divider Calibration 2-98. Internal CAL Zero Amplifier ahp014f.eps Figure 2-16. Divider Gain Calibration 2-101. Basic DAC Theory of Operation 2-99. Switch Matrix 5725A Amplifier Interface2-100. DAC Assembly A11 0.1 x 13V + 0.5 x 0.78 mV = ahp015f.eps Figure 2-17. DAC Assembly Simplified Schematic Programmable Peripheral Interface IC U31 is the heart of this circuit 2-102. DAC Assembly Digital Control2-103. DAC Assembly Reference Circuitry 2-104. Duty-Cycle Control Circuit REFCOM 2-105. DAC Filter Circuit2-106. DAC Output Stage 2-108. Linearity Control Circuit 2-107. Sense Current Cancellation Circuit 2-111. DAC Buffered Reference Sip 2-110. DAC Output Switching2-109. Negative Offset Circuit 2-114. ADC Input Selection 2-112. Calibration Hardware2-113. ADC Amplifier ∙ ADC reference voltage ∙ ADC dac ∙ ADC comparator/amplifier 2-115. ADC Circuit ahp016f.eps Figure 2-18. ADC Circuit Measurement Functions INPUT 2-117. DAC Assembly Calibration2-116. How the DAC is Used in Calibration 2-118. Oscillator Section Overview 2-119. Oscillator Control Assembly A12 2-120. Oscillator Control Digital Control 2-121. Oscillator Input Switching2-122. Sense Current Cancellation 2-126. Analog Amplitude Control Loop 2-124. Error Integrator2-123. Averaging Converter 2-125. Three-Pole Filter ahp017f.eps Figure 2-19. Oscillator Control Analog Control Loop 2-127. AC/DC Thermal Transfer Circuit ahp018f.eps Figure 2-20. AC/DC Thermal Transfer Circuit 2-128. Oscillator Calibration 2-129. AC/DC Frequency Response Characterization 2-130. Oscillator Output Assembly A13 ahp019f.eps Figure 2-21. Quadrature RC Oscillator Circuit 2-132. Quadrature RC Oscillator 2-131. Oscillator Output Digital Control 2-133. Oscillator Amplitude Control 2-134. Phase−locked Loop 2-135. 2.2V and 22V Range Output Amplifier 2-136. Oscillator Wideband Smd Assembly A13A1 2-137. Output Stage 2-138. Phase Shifter2-139. Power Amplifier Assembly A16 1. Write the proper data for these relays to port A of the 82C55 U11 2-140. Power Amplifier Digital Control Sip Assembly A16A1 ∙ ±185V ∙ ±365V 2-141. PA Common Circuitry2-142. +PA and -PA Supplies 2-143. PA Input Stage 2-145. PA Output Stage 2-144. PA Mid Stage 2-148. PA Operation 220V DC Range 2-146. PA Sense Current Cancellation Circuitry2-147. PA in Standby ahp020f.eps Figure 2-22. Power Amplifier Simplified Schematic 2-152. High Voltage DC 1100V Range and Current 2.2A Range 2-150. High Voltage Assembly Support Mode2-149. PA Operation 220V AC Range 2-151. High Voltage AC 1100V Range 2-154. PA Calibration 2-153. 220V DC Internal Calibration Network ahp021f.eps Figure 2-23. Power Amplifier DC Calibration Network Power Amplifier dc gain of approximately -20 is calibrated next. The Power Amplifier is configured as in the 220V dc operation, except the input is connected to the DAC’s 6.5V reference BRF6 and BSRF6 by U2C and U2D respectively. The resulting -130V at the Power Amplifier output is connected to the 175 kΩ end of the internal cal resistor network by relay K3. The 25 kΩ end of this network is connected to DAC OUT HI and DAC SENSE HI by relay K1. The output of the internal cal amplifier is connected to the DAC’s adc circuit as in the previous steps, and the DAC OUTPUT is adjusted until checkpoint is measured by the adc circuit. Since the exact attenuation of the resistor networks is already known, the exact Power Amplifier output voltage can be calculated. This in turn gives the exact Power Amplifier dc gain, since the exact value of 6.5V reference BSRF6 is known f2-24.eps Figure 2-24. Power Amplifier Calibration AC Attenuator 2-156. 1100V AC Range 2-155. High Voltage Assemblies A14 and A15 ahp022f.eps Figure 2-25. High Voltage/High Current Assembly 1100V AC Range 2-159. HV DC Output Series Pass and Current Limit Circuit 2-158. HVDC Power Supply Filter Circuit2-157. 1100V DC Range ahp023f.eps Figure 2-26. High Voltage/High Current Assembly 1100V DC Range 2-161. 2.2A Range 2-160. DC HV Amplifier/AC Sense Buffer ahp024f.eps Figure 2-27. High Voltage/High Current Assembly 2.2A AC and DC Ranges 2-162. 2.2A Power Supply Filter Circuit 2-163. High Voltage Digital Control 2-165. Calibration of the AC Function 2-164. High Voltage Calibration ahp025f.eps Figure 2-28. High Voltage/High Current Assembly Calibration 2-167. High Voltage Magnitude Control 2-166. Calibration of the Current Function ahp026f.eps 2-168. Ohms Overview 2-170. Selection of Resistance Values 2-169. Ohms Main Assembly A10 ahp38f.eps Figure 2-30. Ohms Assemblies Simplified Schematic ahp39f.eps Figure 2-31. Ohms Main Assembly Simplified SchematicAnalog Selection Detailed Circuit Description 2-174. Ohms CAL Digital Control 2-171. Ohms Main Assembly Support of Current Function Calibration2-173. Ohms Cal Assembly A9 2-172. Ohms Digital Control 2-175. 1, 1.9, and Short Resistance 2-176. Two-Wire Ohmmeter Compensation Circuit ahp027f.eps Figure 2-32. Two-Wire Lead Drop Compensation Circuit 2-180. Ohms Calibration 2-177. Two-Wire Compensation Power Supplies2-178. High Side Cancellation 2-179. Low Side Cancellation ahp028f.eps Figure 2-33. Calibration to an External 10 kΩ Standard 2-181. Calibrating to the External 10 KW Standard 2-184. Completion of High Resistance Value Calibration 2-182. Calibrating 10 KW and 19 KW2-183. Calibrating 100 KW The 10Ω, 19Ω, 100Ω and 190Ω resistance values are determined using 2V from the 2/5/10V source and using internal 101 divider Z5 in conjunction with the DAC. To get 2V, Q2 and Q3 are both turned on, which parallels both the 11.535 kΩ value and the 3.846 kΩ value with the 50 kΩ value. The lower voltage is required to lower the power dissipation in the resistors ahp029f.eps Figure 2-34. Ratio Calibration, 10 Ω From 100 Ω 2-185. Calibrating to the External 1W Standard 2-186. Current/High Resolution Oscillator Assembly Overview A7 2-187. Current Section 2-188. Current Input Switching ahp030f.eps Figure 2-35. Current Output Simplified Schematic 2-191. Shunt Resistors 2-189. Complementary Drive Circuit2-190. Transconductance Amplifiers Table 2-15. Relay Settings for Current Range Selection Range 2-193. Current Output Switching2-192. Feedback Loop 2-194. Generation of the 2.2A Range 2-197. Current/Compliance Voltage Monitor 2-198. Current Assembly Calibration2-195. Current Guard Buffer 2-196. Compliance Limiter ahp031f.eps Figure 2-36. Current Assembly Calibration ∙ 10.00 Hz to 119.99 Hz ∙ 0.1200 kHz to 1.1999 kHz 2-199. High-Resolution Oscillator Section 2-200. Reference Frequency Amp/Divider 2-201. Phase-Locked Loop 2-202. 5-500k Output Divider 2-203. Hi-Res Output Switching2-204. Rear Panel Assembly A21 ∙ RPDUARTCS*, D00000-D0001F ∙ RPIEEECS*, D00020-D0002F 2-205. Rear Panel Power Supplies2-206. Rear Panel Address Mapping 2-209. RS-232C Interface 2-207. Clock Regeneration Circuit2-208. IEEE-488 GPIB Interface 2-211. 5725A Interface 2-212. Phase Lock In/Variable Phase out2-210. Auxiliary Amplifier Interface Port A PA0-PA7 provides the input lines for relay driver U16 2-213. Rear Panel Relay Control2-214. Rear Panel CPU Interface 2-218. Wideband Oscillator Digital Control 2-216. Wideband Oscillator Assembly A62-217. Wideband Oscillator Power Supplies 2-215. Wideband AC Module Option 2-219. Phase-Locked Loop and Divider Circuit 2-221. Wideband Oscillator Filters 2-220. Amplitude Control Amplifier and X10 Wideband Amplifier Figure 2-37 is a simplified schematic for the Wideband Output assembly 2-222. Wideband Output Assembly A5 ahp032f.eps Figure 2-37. Wideband Output Assembly Simplified Schematic 2-223. Wideband Output Power Amplifier Circuit 2-226. Wideband Output Overload Control Circuit 2-224. Wideband Output Attenuators2-225. Wideband Output RMS Sensor and Amplitude Control Circuit 2-228. Wideband Output Calibration 2-227. Wideband Output Digital Control connector is connected back to the OUTPUT HI SENSE and OUTPUT LO SENSE binding posts 5700A/5720A Series II Calibrator Calibration and Verification 3-30 Calibration and Verification 3-1. Introduction 3-2. Accessing the Fuse Cleaning the Air Filter 3-3. Cleaning the Air Filter 3-6. Calibrating the 5700A/5720A Series II to External Standards 3-4. Cleaning the Exterior3-5. Calibration Calibrating the 5700A/5720A Series II to External Standards 3-8. When to Adjust the Calibrator’s Uncertainty Specifications3-7. Calibration Requirements 3-9. Calibration Procedure 732B DC STANDARD 4. Enter the ambient temperature then press E. The display shows5. Connect the 732B to the calibrator as shown in Figure Figure 3-3. 732B External Calibration Connections IF3-7.EPS IF3-5.EPSIF3-6.EPS After a few seconds, the following display appears F7-4.EPS RESISTANCE STANDARDCALIBRATOR Figure 3-4. 742A-1 and 742A-10k External Calibration Connections 16. Set the rear panel CALIBRATION switch to NORMAL 3-10. Range Calibration 4. Press the “DC V” softkey to bring up the next menu shown below IF057.EPS PREV MENU Calibrating the Wideband AC Module Option 5700A-03 3-11. Calibrating the Wideband AC Module Option 5700A-03 2. Press the “Cal “ softkey to bring up the following menu 4. Press the “Gain” softkey to bring up the following display 3-12. Performing a Calibration Check Press Pto exit the calibration menus Figure 3-7. Overview of Verification Tests 3-13. Full Verification 3-14. Required Equipment for All Tests 3-15. Warm-up Procedure for All Verification Tests Equipment Required for Wideband Ac Module Option 5700-03 Verification Table 3-2. List of Required Equipment for Main OutputEquipment Application 3-16. Resistance Verification Test 13. The low-value 1Ω, 1.9Ω, and 10Ω tests are summarized in Table 3-17. Two-Wire Compensation Verification 3-18. DC Voltage Verification Test 3-19. DC Voltage One-Tenth Scale Linearity Test 3-20. Direct Current Accuracy Verification Test 3-22. Output Level Tests For AC V Ranges 3-21. AC Voltage Frequency Accuracy Test Use Table 3-23 5720A or Table 3-24 5700A for the test records 5700A/5720A Series II Output Level 3-23. AC Current Test, 22 mA to 11A RangesTable 3-8. 5790A Adjustment Counts 5790A Adjustment Counts 1. Connect the equipment as shown in Figure 3-12A use the 2A shunt 5790A Figure 3-12. Alternating Current Test SetupA. Alternating Current Test Setup, 22 mA to 2A Using 5790A Input B. Alternating Current Test Setup, 10A Using 5790A Input Pomona Cable 1362-A-18 3-24. AC Current Test, 2 mA and 200 μA RangesHi Output Lo Metal Film Resistor Mounted on Dual Banana Plug 200 Figure 3-15. Metal Film Resistor in Test Circuit 3-25. Rationale for Using Metal-Film Resistors to Measure AC CurrentFigure 3-14. Metal Film Resistor Equivalent Circuit 3-27. Wideband AC Voltage Module Output Verification 3-26. Wideband Frequency Accuracy Test Wideband Output Accuracy at 1 kHz Test 3-28. Wideband Output Accuracy at 1 kHz Test 3-29. Wideband Output Flatness Test 3-30. Wideband Flatness Calibration Procedure 3-32. DC Voltage Load Regulation Test 3-31. Optional Tests Optional Tests 3-33. DC Voltage Linearity Test3-34. DC Voltage Output Noise 10 Hz to 10 kHz Test 2. Set the Oscilloscope Differential Amplifier controls as shown below WWarning 3-37. Wideband Distortion Testing3-35. DC Voltage Output Noise 0.1 to 10 Hz Test 3-36. AC Voltage Distortion Test 3-38. AC Voltage Overshoot Test 3-39. Minimum Use Requirements Calibration Equipment Minimum Use SpecificationsMinimum Use Requirements Table 3-15. Minimum Use Requirements 3-40. Determining Test Limits for Other Calibration Intervals 130 + 1000000*0.000000040/0.002=130 ppm + 20 ppm = 150 ppm Measured 1Ω Std Voltage DMM Error1Ω Std Res Value 1Ω Std Voltage UUT True Res Value Table 3-16. 5720A Resistance Test Record contDMM UUT Res Value UUT True Res Table 3-17. 5700A Resistance Test RecordUUT 1Ω Displayed Value UUT 1Ω Voltage Difference of Characterized to Nominal Value Table 3-17. 5700A Resistance Test Record cont Max 5720A Output Divider SettingTable 3-18. DC Voltage Test Record for 5720A 5720A Range 5700A Output Table 3-19. DC Voltage Test Record for 5700A5700A Range Table 3-20. Direct Current Accuracy Test Record 5720A UUT ErrorSetting Error A+B DC DMM Reading Table 3-21. Direct Current Accuracy Test Record 5700A5725A Amplifier DC Current Test Test Limit 90-day ppm Level Error Display ReadingTable 3-23. 5720A AC Voltage Output Test Record Output Display ErrorOutput Level Table 3-23. 5720A AC Voltage Test Record cont Table 3-24. 5700A AC Voltage Output Test Record Limits Table 3-24. 5700A AC Voltage Output Test Record contTable 3-25. AC Voltage 2 mV Range Test Record Characterized 1.9 mV Reading 2A, 200 mA, 20 mA and 10A Test Record UUT Error DisplayCalculated Error Table 3-26. 5720A AC Current 20 mA to 10A Accuracy Test Record Specs ±ppm Table 3-27. 5700A AC Current 20 mA to 10A Accuracy Test Record2A, 200 mA, 20 mA and 10A Test Record 10A Only for 5725A Test Limits ± ppm Table 3-28. 5720A AC Current 2 mA and 200 μA Accuracy Test RecordSpec ± ppm 90-day 5790A Transfer Spec ± ppm Tolerance Limits Table 3-30. Wideband Frequency Accuracy Test RecordFrequency Hz Frequency Measured 5790A 1-Year Spec ± ppm Measured ErrorMeasured Flatness Error Table 3-31. Wideband Accuracy at 1 kHz Test Record Table 3-32. Wideband Flatness Test Record cont Error Sum ppm Table 3-33. Wideband Absolute Error 10 Hz to 500 kHz1 kHz Absolute Error ppm Flatness Error ppm 5700A/5720A Series Range Div. SettingKelvin-Varley Setting Table 3-34. Load Regulation Test Record Load Resistors UUT Error Display ReadingTable 3-37. AC V Distortion Test Summary 5700A/5720A Series II Output Fluke Corporation A Message Fromstatic awareness 5. USE STATIC SHIELDING CONTAINERS FOR HANDLING AND TRANSPORT Title Maintenance 5700A/5720A Series II Calibrator 4-1. Introduction 4-2. Cleaning the Air Filter 4-9. Rear Panel Removal and Installation 4-3. General Cleaning4-4. Cleaning PCA’s 4-5. Access Procedures 4-10. Rear Panel Assembly Access 4-12. Display Assembly Removal and Installation 4-11. Front Panel Removal and Installation 4-14. Analog Assembly Removal and Installation 4-13. Keyboard Assembly Removal and Installation FRONT PANEL Figure 4-5. Analog and Digital Assemblies 4-17. Hybrid Cover Removal 4-18. Front/Rear Binding Post Reconfiguration4-15. Digital Assembly Removal and Installation 4-16. Power Transformer Removal and Installation 6. Install the Front Panel 4-20. Clearing Ghost Images from the Control Display 4-19. Installing a Wideband AC Module Option4-21. Replacing the Clock/Calendar Backup Battery ETIME 4-22. Using Remote Commands Reserved for Servicing4-23. Using the ETIME Command Using The Fatality? and Fatalclr Commands Response FATALITY?FATLCLR? 5700A/5720A Series II Calibrator Troubleshooting 5700A/5720A Series II Calibrator 2703 A7 8255 Port C Fault 5-2. Interpreting Diagnostic Fault Codes2701 A7 8255 Port a Fault 2702 A7 8255 Port B Fault 2709 A7 Current Magnitude Fault 2705 A7 Oven Regulation Fault2706 A7 Current Compliance Fault 2707 A7 Hardware Initialization Fault 2714 A7 Hi-res Loop In 1kHz Range 2718 Fault In Setting Up AC For Diagnostics2719 A7 8255 Was Reset 2713 A7 Hi-Res Loop In 100Hz Range 2804 A11 DAC Heaters Not Regulated 2801 A11 8255 Port a Wires2802 A11 8255 Port B Data Bus 2803 A11 8254 Status Words 2811 A11 -11V DC Range Fault 2808 A11 ADC Amp Gain Error2809 A11 DAC Monitoring Fault 2810 A11 +11V DC Range Fault 2818 Assembly A11 Missing 2815 A11 6.5V Reference Fault2816 A11 13V Buffered Reference Fault 2817 A11 13V Reference Fault 3102 A14 8255 Port B Fault 2822 A8/A11 -11/22V DC Zero Estimate Fault2826 A11 A/D Overload Fault 3101 A14 8255 Port a Fault 3106 A15 DC HV Amp Noise Fault 3103 A14 8255 Port C Fault3104 A15 HV Oven Regulation Fault 3105 A15 HV I Oven Regulation Fault 3112 A15 HV +DC Ref/error Amplitude Fault 3109 A15 HV +DC Preamplifier Fault3110 A15 HV +DC Series Pass & Current Fault 3111 A15 HV +DC High Voltage Output Fault 3119 A14/A15 HV +DC Current Abs. Value 3116 A15 HV -DC Reference/error Amp Fault3117 A14/A15 HV +DC Current Error Amp Fault 3118 A14/A15 HV -DC Current Error Amp Fault 3124 A14/A15 HV AC 1kHz, Preamp Hi 3126 A14/A15 HV AC 100Hz, Preamp Fault3122 A14/A15 HV AC 1kHz, Preamp Lo 3123 A14/A15 HV AC 1kHz, Preamp Mid 3131 A14/A15 HV AC 100Hz, Output Lo 3128 A14/A15 HV AC 1kHz, Output Lo3129 A14/A15 HV AC 1kHz, Output Mid 3130 A14/A15 HV AC 1kHz, Output Hi 3134 Spare 3135 Assembly A14 Not Responding3136 A14 8255 Was Reset 3137 A14/A15/A16 2.2A AC Range Mag. Fault 3141 A14/A15/A16 2.2A DC Range Dummy Load 3301 A9 8255 Port a Fault3302 A9 8255 Port B Fault 3140 A14/A15/A16 2.2A AC Range Abs. Value 3306 A9 2V Source Fault 3303 A9 8255 Port C Fault3304 A9 10V Source Fault 3305 A9 5V Source Fault 3312 A9/A10 Ohms 11 Divider Fault 3309 A9 Diff Amp Gain Fault3310 A9 Diff Amp Noise Fault 3311 A9/A10 Ohms 101 Divider Fault 3318 A9/A10 190 Kilohm Ratio Fault 3315 A9/A10 10 Ohm Cal Diag Fault3316 A9/A10 19 Ohm Cal Diag Fault 3317 A9/A10 100 Kilohm Ratio Fault 3326 A9/A10 19 Kilohm Check Fault 3321 A9/A10 10M Ohm Ratio Fault3324 A9/A10 100M Ohm Ratio Fault 3325 A9/A10 10 Kilohm Check Fault 3330 A9/A10 190 Ohm Check Fault 3327 A9/A10 1 Kilohm Check Fault3328 A9/A10 1.9 Kilohm Check Fault 3329 A9/A10 100 Ohm Check Fault 3337 A9/A10 Ohms Correction Factor Fault 3334 A9/A10 1.9 Ohm Check Fault3335 A9/A10 Ohms Short Check Fault 3336 A9/A10 2 Wire Compensation Fault 3402 A12 8255 Port B 3341 A9/A10 190 Ohm Cal Diag Fault3400 A12 8255 Control Word 3401 A12 8255 Port A 3412 A12 To A13 Interface Fault 3408 A13 Fixed Ampl. Osc Fault3409 A13 Phase Lock Loop Fault 3410 A12/A13 22V Amp Bias Adj Error 3414 A12/A13 Nonlinear Control Loop 2vrng 3416 A12/A13 DAC 15th Bit Fault3417 A12 DC Sensor Buffer Fault 3418 A12 Sensor Loop/SQ. Root Amp Fault 3426 A12 8255 Was Reset 3423 Assembly A12 Missing3424 Assembly A13 Missing 3425 Assembly A12 Or A13 Not Responding 3504 Spare 3508 A16/A14 220V AC Range Output Fault3510 A16 220V Amp Fault 3503 A16 8255 Port C 3513 Spare 3520 A16 PA Oven Regulation Fault3511 A16 Incorrect PA Input 3512 Spare 3526 220V AC Initialization Fault 3521 Assembly A16 Is Not Responding3524 A16 Power Amp Is Too Hot 3525 220V DC Initialization Fault 3602 +15S Supply Fault 3530 A16 8255 Was Reset3600 +17S Supply Fault 3601 -17S Supply Fault 3608 +5rLH Supply Fault 3605 -42S Supply Fault3606 LH Com Ground Fault 3607 -5lH Supply Fault 3614 OSC Com Ground Fault 3611 -PA Supply Fault3612 +15 OSC Supply Fault 3613 -15 OSC Supply Fault 3703 A21 8255 Port C Fault 3615 S Com Ground Fault3701 A21 8255 Port A Fault 3702 A21 8255 Port B Fault 3804 A8 Zero Amp Lo Noise Fault 3801 A8 8255 Port A Fault3802 A8 8255 Port B Fault 3803 A8 8255 Port C Fault 3814 A8 220mV Divider Fault 3815 A8 22mV Divider Fault 3816 Spare 3809 A8 Zero Amp Hi Gain Fault3810 A8 2.2V Amp Noise Fault 3811 A8 Zero Amp Offset 3812 A8 2.2V Gain Fault 3813 A8 220mV Offset Fault 3827 Assembly A8 Too Hot 3900 A5 8255 Control Word 3824 A8 Oven Regulation Fault3825 Assembly A8 Not Responding 3826 A8 8255 Was Reset 3908 A5 Rms Sensor At 30MHz 3905 A6 Phase Lock Loop At 10MHz3906 A6 Phase Lock Loop At 30MHz 3907 A5 Rms Sensor At 10MHz 3912 A5/A6 Output Offset At 10MHz 3914 A5 0DB Output Attenuation Fault3915 A5 10DB Output Attenuation Fault 3911 A5/A6 Ampl. Control At 30MHz 3922 A5/A6 Wideband Initialization Fault 3916 A5 20DB Output Attenuation Fault3917 A5 30DB Output Attenuation Fault 3918 A5 40DB Output Attenuation Fault 5-4. Troubleshooting the Wideband Output Assembly A5 5-3. Component-level Troubleshooting3923 A5 8255 Was Reset Component-level Troubleshooting All measurements are referenced to SCOM TP16 or TP17 and all 5-5. Troubleshooting the Wideband Oscillator Assembly A6 F5-2.EPS Figure 5-2. Waveform at TP1 F5-3.EPS Figure 5-3. Waveform at TP15 F5-4.EPS Figure 5-4. Waveform at Pins 14 and 15 of U1 F5-5.EPS 10 ms 5-7. Current Section 5-6. Troubleshooting the Current/Hi-Res Assembly A7 F5-6.EPS Figure 5-6. Waveform at Pin 11 of K2 K10, K13 Figure 5-7. Waveform at Pin 6 of K21.2 Ω K5C, K5D F5-10.EPS F5-9.EPS F5-11.EPS All measurements are referenced to LHCOM TP18 5-8. Hi-Res Oscillator Section F5-13.EPS Figure 5-13. Waveform at TP12 5-9. Troubleshooting the Switch Matrix Assembly A8 F5-15.EPS Figure 5-15. Waveform at TP16 5-11. Two-wire Compensation Circuit 5-10. Troubleshooting the Ohms Cal Assembly A9 5-12. Troubleshooting the Ohms Main Assembly A10 5-13. Troubleshooting the DAC Assembly A11 F5-18.EPS Figure 5-17. Waveform at TP6Figure 5-18. Waveform at TP4, Calibrator Set to F5-17.EPS F5-19.EPS Figure 5-19. Waveform at TP4, Calibrator Set to F5-20.EPS Figure 5-20. Waveform at TP7 F5-21.EPS Figure 5-21. Waveform at TP5 5-14. Duty-cycle Control Circuit F5-22.EPS Figure 5-22. Waveform at Pin 10 of U6 F5-24.EPS Figure 5-23. Waveform at Pin 6 of U13Figure 5-24. Waveform at Pin 4 of U10 F5-23.EPS U11, Q30, Q31, Q32, and their associated components 5-15. ADC Circuit 5-16. Buffered Reference SIP Assembly A11A2 5-17. Troubleshooting the Oscillator Control Assembly A12 F5-28.EPS Figure 5-27. Waveform at Anode of CR4Figure 5-28. Waveform at Pin 6 of U11 F5-27.EPS F5-29.EPS Figure 5-29. DC Sense Buffer Waveform TP6 5-18. Troubleshooting the Oscillator Output Assembly A13 ∙ TP5 positive voltage ∙ TP4 negative voltage ∙ TP3 positive voltage 5-19. Troubleshooting the High Voltage Control Assembly A14 F5-31.EPS Figure 5-31. Waveform at TP3 5-20. Magnitude Control Circuit 5-21. Troubleshooting the High Voltage/High Current Assembly A15 operation refer to Figure 2-25 in the Theory of Operation section. During normal operation in the 1100V ac mode, internal software monitors the output and makes corrections or trips the instrument into standby. This internal monitoring can cause difficulty when troubleshooting a faulty High Voltage assembly. If during the next step 8 the instrument keeps tripping into standby, defeat the monitoring by connecting a jumper from TP9 to TP10 on the DAC assembly Figure 5-32. Waveform at Pin 18 of Hybrid H4 5-22. Troubleshooting the Power Amplifier Assembly A16 Figure 5-33. Power Amplifier with Calibrator Set to 22V at 1 kHz Remove any jumpers left in place from step 8 before continuing AC elsewhere in the Calibrator 5-23. Troubleshooting the Filter/PA Supply Assembly A18 J201. The +PA supply at +180Vshould go into current limit. The oscilloscope should show a repeating pattern in which the +PA supply climbs to about +180V then drops to 0V. If a failure is detected, check Q203, VR246, VR213, U201C, and associated components 5700A/5720A Series II Calibrator List of Replaceable Parts 5700A/5720A Series II Calibrator 6-3. Manual Status Information 6-2. How to Obtain PartsA * symbol indicates a device that may be damaged by static discharge 6-1. Introduction Fluke 6-5. Service CentersManual Status Information Assembly Name Ref or Option No Fluke Stock No Service CentersTable 6-1. Front Panel Final Assembly Reference Description Designator f6-1.eps Figure 6-1. Front Panel Final Assembly5700A-T&B Table 6-1. Chassis Final Assembly f61a1.eps Figure 6-2. Chassis Final Assembly5700A T&B 1 of f61a2.eps Figure 6-2. Chassis Final Assembly cont Table 6-1. Rear Panel Final Assembly f61b.eps Figure 6-3. Rear Panel Final Assembly LED,GREEN,SUBMINIATURE ISOLATOR,OPTO,OPTICAL SWITCH,INFRAREDTable 6-2. A1 Keyboard PCA CR1-4 DT1, DT2 W1 Figure 6-4. A1 Keyboard PCA 5700A-1603 Designator Table 6-3. A2 Front Panel PCA Table 6-3. A2 Front Panel PCA cont 57001602.EPS 5700A-1602Figure 6-5. A2 Front Panel PCA Table 6-4. A3 Analog Motherboard PCA Figure 6-6. A3 Analog Motherboard PCA 5700A-1601 Table 6-5. A4 Digital Motherboard PCA 57001605.EPS 5700A-1605Figure 6-7. A4 Digital Motherboard PCA Table 6-6. A5 Wideband Output PCA, Option Table 6-6. A5 Wideband Output PCA, Option -03 cont R69,R70 R72,R73,R80-83 R74 R75 R78,R79,R86-89 R92-95 R96-99 R100 R101 57001611.EPS 5700A-1611Figure 6-8. A5 Wideband Output PCA, Option Table 6-7. A6 Wideband Ocillator PCA, Option Table 6-7. A6 Wideband Ocillator PCA, Option -03 cont CONNECTOR ,CONN,DIN41612,TYPE C,RT ANG,64 PIN R58,R112,R212 R312,R412,R512 R59 R61 R62,R64,R65,R69 R63 R68 R71 57001610.EPS 5700A-1610Figure 6-9. A6 Wideband Oscillator PCA, Option Table 6-8. A7 Current/High-Res Oscillator PCA Table 6-8. A7 Current/High-Res Oscillator PCA cont Designator 57001621.EPS 5700A-1621Figure 6-10. A7 Current/HIgh-Res Oscillator PCA Reference Designator Table 6-9. A8 Switch Matrix PCA Table 6-9. A8 Switch Matrix PCA cont 57001622.EPS Figure 6-11. A8 Switch Matrix PCA5700A-1622 Table 6-10. A9 Ohms Cal PCA Table 6-10. A9 Ohms Cal PCA cont 57001631.EPS 5700A-1631Figure 6-12. A9 Ohms Cal PCA Table 6-11. A10 Ohms Main PCA 57001630.EPS 5700A-1630Figure 6-13. A10 Ohms Main PCA C110,C111 CR1,CR3-6,CR8, CR12,CR13 CR2 Table 6-12. A11 DAC PCA Table 6-12. A11 DAC PCA cont Table 6-12. A11 DAC PCA cont VR13 VR18,VR22 VR25 VR26 VR27 VR28 VR29 VR33,VR34 X1 Z2 Z4 Z5 Z8 Z10 57001640.EPS 5700A-1640Figure 6-14. A11 DAC PCA Table 6-13. A11A1 DAC Filter SIP PCA Figure 6-15. A11A1 DAC Filter SIP PCA 5700A-1643 Table 6-14. A11A2 DAC Buffered Reference SIP PCA Figure 6-16. A11A2 DAC Buffered Reference SIP PCA 5700A-1644 Table 6-15. A12 Oscillator Control PCA Stock Table 6-15. A12 Oscillator Control PCA cont Designator 57001650.EPS 5700A-1650Figure 6-17. A12 Oscillator Control PCA Table 6-16. A13 Oscillator Output PCA Table 6-16. A13 Oscillator Output PCA cont Table 6-16. A13 Oscillator Output PCA cont 57001651.EPS 5700A-1651Figure 6-18. A13 Oscillator Output PCA Table 6-17. A13A1 Oscillator Wideband SMD PCA Figure 6-19. A13A1 Oscillator Wideband SMD PCA 5700A-1652 Table 6-18. A14 High Voltage Control PCA Table 6-18. A14 High Voltage Control PCA cont 57001661.EPS 5700A-1661Figure 6-20. A14 High Voltage Control PCA Table 6-19. A15 High Voltage/High Current PCA Table 6-19. A15 High Voltage/High Current PCA cont 57001660.EPS 5700A-1660Figure 6-21. A15 High Voltage/High Current PCA CR20,CR21,CR23 Table 6-20. A16 Power Amplifier PCA R9,R10,R16,R33, R40,R50 R59, R115,R148 R149 R11,R12 Table 6-20. A16 Power Amplifier PCA cont 5700A/5720A Series II Calibrator 57001670.EPS Figure 6-22. A16 Power Amplifier PCA5700A-7670 Table 6-21. A16A1 Power Amplifier Digital Control SIP PCA 5700A-1671 Figure 6-23. A16A1 Power Amplifier Digital Control SIP PCA Table 6-22. A17 Regulator/Guard Crossing PCA Table 6-22. A17 Regulator/Guard Crossing PCA cont 57001680.EPS 5700A-1680Figure 6-24. A17 Regulator/Guard Crossing PCA CR1,CR2,CR04, CR5 CR8,CR10, CR12,CR13 Table 6-23. A18 Filter/PA Supply PCA Table 6-23. A18 Filter/PA Supply PCA cont VR211,VR217 VR227,VR231 VR212,VR216 VR226,VR232 VR214,VR230 57001690.EPS 5700A-7690Figure 6-25. A18 Filter/PA Supply PCA C24,C25 CR1-4,CR9-12 CR8,CR16, CR21- 24,CR29-34 Table 6-24. A19 Digital Power Supply PCA Table 6-24. A19 Digital Power Supply PCA cont 57001604.EPS Figure 6-26. A19 Digital Power Supply PCA5700A-1604 Part Number Table 6-25. A20 CPU PCARef Des Table 6-26. A20 CPU PCA cont 57001606.EPS Figure 6-27. A20 CPU PCA Table 6-27. A21 Rear Panel PCA Table 6-27. A21 Rear Panel PCA cont 57001609.EPS 5700A-1609Figure 6-28. A21 Rear Panel PCA 5700A/5720A Series II Calibrator Schematic Diagrams 5700A/5720A Series II Calibrator Figure 7-1. A1 Keyboard PCA Schematic Diagrams Figure 7-1. A1 Keyboard PCA cont 5700A/5720A Series Figure 7-2. A2 Front Panel PCA Figure 7-2. A2 Front Panel PCA cont Figure 7-2. A2 Front Panel PCA cont Schematic Diagrams Figure 7-2. A2 Front Panel PCA cont Service Manual5700A/5720A Series Figure 7-2. A2 Front Panel PCA cont Figure 7-3. A3 Analog Motherboard PCA Figure 7-23. A3 Analog Motherboard PCA cont Figure 7-3. A3 Analog Motherboard PCA cont Figure 7-3. A3 Analog Motherboard PCA cont Schematic Diagrams Figure 7-3. A3 Analog Motherboard PCA cont Figure 7-4. A4 Digital Motherboard PCA Figure 7-4. A4 Digital Motherboard PCA cont ahp46f.tif Figure 7-4. A4 Digital Motherboard PCA cont Figure 7-5. A5 Wideband Output PCA Option 5700A-1611 Figure 7-5. A5 Wideband Output PCA Option -03 cont Figure 7-5. A5 Wideband Output PCA Option -03 cont Schematic Diagrams Figure 7-5. A5 Wideband Output PCA Option -03 cont Figure 7-6. A6 Wideband Oscillator PCA Option 7-235700A-7610 Figure 7-6. A6 Wideband Output PCA Option Figure 7-6. A6 Wideband Oscillator PCA Option -03 cont Figure 7-6. A6 Wideband Oscillator PCA Option -03 cont 5700A-1621 Figure 7-7. A7 Current/High-Resolution Oscillator PCA Figure 7-7. A7 Current/High-Resolution Oscillator PCA cont Figure 7-7. A7 Current/High-Resolution Oscillator PCA cont Schematic Diagrams 5700A/5720A Series Oscillator PCA cont Figure 7-7. A7 Current/High-Resolution7-31 5700A-1021 4 of 5700A-1622 Figure 7-8. A8 Switch Matrix PCA Figure 7-8. A8 Swith Matrix PCA cont Figure 7-8. A8 Switch Matrix PCA cont Figure 7-8. A8 Swith Matrix PCA cont Schematic Diagrams 5700A/5720A Series Service ManualFigure 7-8. A8 Switch Matrix PCA cont Figure 7-8. A8 Swith Matrix PCA cont 5700A-1631 Figure 7-9. A9 Ohms Cal PCA Figure 7-9. A9 Ohms Cal PCA cont Figure 7-9. A9 Ohms Cal PCA cont Service Manual5700A/5720A Series Figure 7-9. A9 Ohms Cal PCA cont Schematic Diagrams Figure 7-9. A9 Ohms Cal PCA cont Figure 7-10. A10 Ohms Main PCA Figure 7-10. A10 Ohms Main PCA cont Figure 7-10. A10 Ohms Main PCA Schematic Diagrams Figure 7-10. A10 Ohms Main PCA cont Service Manual5700A/5720A Series Figure 7-10. A10 Ohms Main PCA 5700A-7640 Figure 7-11. A11 DAC PCA Figure 7-11. A11 DAC PCA cont 200K 22uFR128 C112 Figure 7-11. A11 DAC PCA cont 7-52 Figure 7-11. A11 DAC PCA cont Schematic Diagrams Figure 7-11. A11 DAC PCA cont Figure 7-12. A11A1 DAC Filter SIP PCA Figure 7-13. A1142 DAC Buffered Reference SIP PCA Figure 7-14. A12 Oscillator Control PCA cont 5700A-7650 DG211 4. C5 AND C55 ARE NOT INSTALLED3. ALL GND CONNECTIONS DENOTED WITH A 1 ARE BUSSED AND CONNECTED TO GND3 AT ONE POINT Figure 7-14. A12 Oscillator Control PCA cont 7-60 Figure 7-15. A13 Oscillator Output PCA Figure 7-15. A13 Oscillator Output PCA cont Figure 7-15. A13 Oscillator Output PCA cont Schematic Diagrams Figure 7-15. A13 Oscillator Output PCA cont Figure 7-16. A13A1 Oscillator Wideband SMD PCA Figure 7-16. A13A1 Oscillator Wideband SMD PCA cont Figure 7-17. A14 High Voltage Control PCA Figure 7-17. A14 High Voltage Control PCA cont 7-68 Figure 7-17. A14 High Voltage Control PCA cont Figure 7-17. A14 High Voltage Control PCA cont Service Manual5700A/5720A Series Figure 7-17. A14 High Voltage Control PCA cont 5700A-1660 Figure 7-18. A15 High Voltage/ High Current PCA Figure 7-18. A15 High Voltage/High Current PCA cont Figure 7-18. A15 High Voltage/High Current PCA cont 5700A-7670 Figure 7-19. A16 Power Amplifier PCA 4. NOT INSTALLED Figure 7-19. A16 Power Amplifier PCA cont 10 M 2N4044 7-78 Figure 7-19. A16 Power Amplifier PCA cont Figure 7-20. A16A1 Power Amplifier Digitial Control SIP PCA Control SIP PCA cont Figure 7-20. A161A1 Power Amplifier Digital7-80 Figure 7-21. A17 Regulator/Guard Crossing PCA 5700A-1680 Figure 7-21. A17 Regulator/Guard Crossing PCA cont Figure 7-21. A17 Regulator/Guard Crossing PCA cont Figure 7-22. A18 Filter/PA Supply PCA 7-845700A-7690 Figure 7-22. A18 Filter/PA Supply PCA cont Figure 7-22. A18 Filter/PA Supply PCA cont Figure 7-23. A19 Digital Power Supply PCA Figure 7-23. A19 Digital Power Supply PCA cont Figure 7-24. A20 CPU PCA Figure 7-24. A20 CPU PCA cont Figure 7-24. A20 CPU PCA cont Schematic Diagrams Figure 7-24. A20 CPU PCA cont Service Manual5700A/5720A Series Figure 7-24. A20 CPU PCA cont Schematic Diagrams Figure 7-24. A20 CPU PCA cont Figure 7-25. A21 Real Panel PCA Figure 7-25. A21 Rear Panel PCA cont Figure 7-25. A21 Rear Panel PCA cont Schematic Diagrams Figure 7-25. A21 Rear Panel PCA cont Service Manual5700A/5720A Series Figure 7-25. A21 Rear Panel PCA cont Schematic Diagrams Figure 7-25. A21 Rear Panel PCA cont Figure 7-26. Hybrids Figure 7-26. Hybrids cont Figure 7-26. Hybrids cont Schematic Diagrams Figure 7-26. Hybrids cont Service Manual5700A/5720A Series Figure 7-26. Hybrids cont Schematic Diagrams 5700A/5720A Series Service Manual