HP E4418A Service Manual Download Page 72

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Theory of Operation
Introduction

4-2

HP EPM-441A/442A Service Guide

Introduction

This chapter describes how each of the power meter’s assemblies operate.
A block diagram is included at the end of the chapter giving you an overall
view of the power meter’s operation.

4402serv.book Page 2 Monday, March 11, 2002 11:34 AM

Summary of Contents for E4418A

Page 1: ...e HP Halbleiterprodukte HP chemische Analysen oder HP Test und Messwesen nun zu der Firma Agilent Technology gehören Um Verwirrung zu vermeiden wurde lediglich bei Produktname und Nummer der vo laufende Firmenname geändert Produkte mit dem Namen Nummer HP XXXX lauten nun mehr Agilent XXXX Z B das Modell HP 8648 heißt nun Agilent 8648 Questo manuale potrebbe contenere riferimenti ad HP o Hewlett Pa...

Page 2: ...YHP または横河ヒューレットパッカード株式会社という語句を Agilent またはアジレントテクノロジー株式会社と変更してくださいヒューレットパッカード社の電子計測半導体製品化学分析ビジネス部門は分離独立しアジレントテクノロジー社となりました社名変更に伴うお客様の混乱を避けるため製品番号の接頭部のみ変更しております例旧製品名 HP 4294A は現在 Agilent 4294A として販売いたしております ...

Page 3: ...Service Guide HP EPM E4418A E4419A EPM 441A 442A Power Meters HP Part no E4418 90006 January 24 1997 ...

Page 4: ...t Hewlett Packard Company All rights reserved Reproduction adaptation or translation without prior written permission is prohibited except as allowed under the copyright laws Printed in the UK 4402serv book Page ii Monday March 11 2002 11 34 AM ...

Page 5: ...he United States National Institute of Standards and Technology to the extent allowed by the Institute s calibration facility and to the calibration facilities of other International Standards Organization members Warranty This Hewlett Packard instrument product is warranted against defects in material and workmanship for a period of one year from date of shipment During the warranty period Hewlet...

Page 6: ...fications for the product or improper site preparation or maintenance NO OTHER WARRANTY IS EXPRESSED OR IMPLIED HP SPECIFICALLY DISCLAIMS THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE Exclusive Remedies THE REMEDIES PROVIDED HEREIN ARE BUYER S SOLE AND EXCLUSIVE REMEDIES HP SHALL NOT BE LIABLE FOR ANY DIRECT INDIRECT SPECIAL INCIDENTAL OR CONSEQUENTIAL DAMAGES WHET...

Page 7: ... a Safety Class I product provided with a protective earthing ground incorporated in the power cord The mains plug shall only be inserted in a socket outlet provided with a protective earth contact Any interruption of the protective conductor inside or outside the instrument is likely to make the instrument dangerous Intentional interruption is prohibited If this instrument is not used as specifie...

Page 8: ...ined service personnel Markings The CE mark shows that the product complies with all the relevant European legal Directives if accompanied by a year it signifies when the design was proven This is the symbol of an Industrial Scientific and Medical Group 1 Class A product The CSA mark is a registered trademark of the Canadian Standards Association External Protective Earth Terminal While this is a ...

Page 9: ...A1 1992 Safety Requirements for Electrical Equipment for Measurement Control and Laboratory Use and has been supplied in a safe condition The instruction documentation contains information and warnings which must be followed by the user to ensure safe operation and to maintain the instrument in a safe condition 4402serv book Page vii Monday March 11 2002 11 34 AM ...

Page 10: ... German Language User s Guide Option ABD Spanish Language User s Guide Option ABE French Language User s Guide Option ABF Italian Language User s Guide Option ABZ Japanese Language User s Guide Option ABJ HP EPM 441A 442A Service Guide is available by ordering Option 915 HP EPM 441A 442A CLIPs Component Location and Information Pack is available by ordering E4418 90007 4402serv book Page viii Mond...

Page 11: ...Packard Japan Ltd Measurement Assistance Center 9 1 Takakura Cho Hachioji Shi Tokyo 192 Japan Tel 81 426 56 7832 Fax 81 426 56 7840 Korea 82 2 769 0800 Malaysia 60 3 291 0213 Philippines 63 2 894 1451 PRC 86 10 6505 0149 Singapore 1800 292 8100 Taiwan 886 3 492 9666 Thailand 66 2 661 3900 For countries in Asia Pacific not listed contact Hewlett Packard Asia Pacific Ltd 17 21 F Shell Tower Times Sq...

Page 12: ...rica and Middle East please call your local HP sales office or representative Austria 1 25000 0 Belgium and Luxembourg 02 778 3417 Baltic Countries 358 08872 2100 Czech Republic 0042 2 4743111 Denmark 45 99 10 00 Finland 90 88 721 France 0 1 69 29 41 14 Germany 0180 532 62 33 Greece 1 7264045 Hungary 1 252 4705 Ireland 01 284 4633 Israel 03 5380 333 Italy 02 92 122 241 Netherlands 020 547 6669 Nor...

Page 13: ... Latin America Hewlett Packard Latin American Region Headquarters 5200 Blue Lagoon Drive 9th Floor Miami Florida 33126 USA 305 267 4245 4220 United States Hewlett Packard Company Test and Measurement Organization 5301 Stevens Creek Blvd Bldg 51L SC Santa Clara CA 95052 8059 1 800 452 4844 In any correspondence or telephone conversations refer to the power meter by its model number which is on the ...

Page 14: ... generating static electricity and by lodging in the rear panel 2 Use the original packaging materials or a strong shipping container that is made of double walled corrugated cardboard with 159 kg 350 lb bursting strength The carton must be both large enough and strong enough to accommodate the power meter and allow at least 3 to 4 inches on all sides of the power meter for packing material 3 Surr...

Page 15: ...wer meter s electrical performance to it s specifications Chapter 3 Adjustments This chapter contains checks and adjustments that ensure proper performance of the power meter Chapter 4 Theory of Operation This chapter describes how each of the power meter s individual assemblies operate Chapter 5 Replaceable Parts This chapter details the power meter s replaceable parts It also explains how to ass...

Page 16: ...About this Guide xiv HP EPM 441A 442A Service Guide 4402serv book Page xiv Monday March 11 2002 11 34 AM ...

Page 17: ...Power Meter Specifications 1 3 Meter 1 3 Accuracy 1 4 Power Reference 1 5 Power Meter Supplemental Characteristics 1 6 Power Reference 1 6 Measurement Speed 1 6 Zero Drift of Sensors 1 7 Measurement Noise 1 7 Settling Time 1 9 Power Sensor Specifications 1 12 General Characteristics 1 13 Rear Panel Connectors 1 13 Environmental Characteristics 1 14 General Conditions 1 14 Operating Environment 1 1...

Page 18: ...ower Reference Level Test 2 10 Description 2 10 Equipment 2 11 Test Setup 2 11 Procedure 2 11 HP E Series Power Sensor Interface Test 2 14 Procedure 2 14 HP E Series Power Sensor Functional Test 2 15 Description 2 15 Equipment 2 15 Procedure 2 16 Performance Test Record 2 18 Adjustments 3 1 Introduction 3 2 Safety Considerations 3 2 Equipment Required 3 3 Post Repair Adjustments 3 3 Power Referenc...

Page 19: ...are Upgrades 5 6 Downloading Firmware 5 6 Assembly and Disassembly Guidelines 5 7 Removing the Power Meter Cover 5 7 Removing the A1 Power Supply Assembly 5 8 Removing the A2 Processor Assembly 5 9 Removing the A4 Interface Assembly 5 10 Removing the A5 Daughter or A6 Measurement Assemblies 5 11 Removing the A7 Fan Assembly 5 12 Removing the Power Meter Battery BT1 5 13 Removing the A3 Front Panel...

Page 20: ...Contents 4 HP EPM 441A 442A Service Guide 4402serv book Page 4 Monday March 11 2002 11 34 AM ...

Page 21: ...st Setup 2 7 2 3 Power Reference Level Test Setup 2 11 2 4 Sensor Functional Test Setup 2 16 2 5 Sensor Functional Test Setup with Attenuator 2 17 3 1 Adjustment Setup 3 4 3 2 A2L9 Adjustment Location 3 5 3 3 Adjustment Setup 3 6 3 4 A2R90 Adjustment Location 3 10 4402serv book Page 5 Monday March 11 2002 11 34 AM ...

Page 22: ...Contents 6 HP EPM 441A 442A Service Guide 4402serv book Page 6 Monday March 11 2002 11 34 AM ...

Page 23: ...tions 1 8 1 4 Settling Time 1 9 1 5 Settling Time 1 10 2 1 Required Equipment 2 3 2 2 Zero Test Results 2 6 2 3 Instrument Accuracy Results 2 9 2 4 Power Reference Level Result 2 13 2 5 Functional Test Result 2 17 2 6 Performance Test Record 2 18 3 1 Post Repair Adjustments Tests and Checks 3 3 4402serv book Page 7 Monday March 11 2002 11 34 AM ...

Page 24: ...Contents 8 HP EPM 441A 442A Service Guide 4402serv book Page 8 Monday March 11 2002 11 34 AM ...

Page 25: ...1 Specifications 4402serv book Page 1 Monday March 11 2002 11 34 AM ...

Page 26: ...wise stated and after performing a zero and calibration Supplemental characteristics which are shown in italics are intended to provide information useful in applying the power meter by giving typical but nonwarranted performance parameters These characteristics are shown in italics or denoted as typical nominal or approximate For information on measurement uncertainty calculations refer to HP App...

Page 27: ...P 8480 series power sensors and HP ECP series power sensors Single Sensor Dynamic Range 90 dB maximum HP ECP series power sensors 50 dB maximum HP 8480 series power sensors Display Units Absolute Watts or dBm Relative Percent or dB Display Resolution Selectable resolution of 1 0 0 1 0 01 and 0 001 dB in logarithmic mode or 1 2 3 and 4 significant digits in linear mode Default Resolution 0 01 dB in...

Page 28: ...o Set digital settability of zero Power sensor dependent refer to Table 1 1 For HP ECP series power sensors this specification applies when zeroing is performed with the sensor input disconnected from the POWER REF Table 1 1 Zero Set Specifications Power Sensor Zero Set HP 8481A 50 nW HP 8481B 50 µW HP 8481D 20 pW HP 8481H 5 µW HP 8482A 50 nW HP 8482B 50 µW HP 8482H 5 µW HP 8483A 50 nW HP 8485A 50...

Page 29: ...1A 442A Service Guide 1 5 Power Reference Power Output 1 00 mW 0 0 dBm Factory set to 0 7 traceable to the US National Institute of Standards and Technology Accuracy 1 2 worst case 0 9 rss for one year 4402serv book Page 5 Monday March 11 2002 11 34 AM ...

Page 30: ...pe N f 50 Ω Measurement Speed Over the HP IB three measurement speed modes are available as shown along with the typical maximum measurement speed for each mode Normal 20 readings second x2 40 readings second Fast 200 readings second for HP ECP series power sensors only Maximum measurement speed is obtained using binary output in free run trigger mode 4402serv book Page 6 Monday March 11 2002 11 3...

Page 31: ...f averages set to 16 for normal mode and 32 for x2 mode Use the Noise Multiplier for the appropriate mode normal or x2 and number of averages to determine the total measurement noise value For example for an HP 8481D power sensor in normal mode with the number of averages set to 4 the measurement noise is equal to 45 pW x 2 75 124 pW Table 1 2 Noise Multiplier Number of Averages 1 2 4 8 16 32 64 1...

Page 32: ...ions For HP ECP series power sensors the measurement noise is measured within the low range Refer to the relevant power sensor manual for further information HP 8481A 10 nW 110 nW HP 8481B 10 µW 110 µW HP 8481D 4 pW 45 pW HP 8481H 1 µW 10 µW HP 8482A 10 nW 110 nW HP 8482B 10 µW 110 µW HP 8482H 1 µW 10 µW HP 8483A 10 nW 110 nW HP 8485A 10 nW 110 nW HP 8485D 4 pW 45 pW HP R8486A 10 nW 110 nW HP R848...

Page 33: ...15 0 18 0 22 0 35 0 55 1 1 1 9 3 5 6 9 14 5 33 10 dB 10 dB 10 dB 20 dB Maximum dBm Minimum dBm Power 150 ms 6 6 s 500 ms 200 ms Settling Times Sensor Dynamic Range 10 dB 10 dB 10 dB 20 dB Maximum dBm Minimum dBm Power Settling Times Sensor Dynamic Range 10 dB 10 dB 10 dB 20 dB Maximum dBm Minimum dBm Power Settling Times Sensor Dynamic Range 10 dB 10 dB 10 dB 20 dB Power 150 ms 3 5 s 350 ms 180 ms...

Page 34: ...wer step crosses the power sensor s auto range switch point add 25 ms Refer to the relevant power sensor manual for further information For HP ECP series power sensors in normal and x2 speed modes manual filter 10 dB decreasing power step Table 1 5 Settling Time Number of Averages 1 2 4 8 16 32 64 128 256 512 1024 Settling Time s Normal Mode 0 07 0 12 0 21 0 4 1 1 8 3 3 6 5 13 27 57 Response Time ...

Page 35: ...tep normal and x2 speed modes 10 dB 10 dB 10 dB 60 dB Maximum dBm Minimum dBm Power Sensor 40 ms 3 4 s 210 ms 70 ms Settling Times Typical Dynamic Range 10 dB 10 dB 10 dB 60 dB Maximum dBm Minimum dBm Power Sensor 70 ms 6 5 s 400 ms 120 ms Settling Times Typical Dynamic Range Normal Mode x2 Mode 4402serv book Page 11 Monday March 11 2002 11 34 AM ...

Page 36: ...for residual offsets Zero Drift This parameter is also called long term stability and is the change in the power meter indication over a long time usually one hour for a constant input power at a constant temperature after a defined warm up interval Measurement Noise This parameter is also known as short term stability and is specified as the change in the power meter indication over a short time ...

Page 37: ...t 1 kΩ output impedance BNC connector HP IB Allows communication with an external controller Ground Binding post accepts 4 mm plug or bare wire connection Line Power Input Voltage Range 85 to 264 Vac automatic selection Input Frequency Range 47 to 63 Hz Power Requirement approximately 50 VA 14 Watts 4402serv book Page 13 Monday March 11 2002 11 34 AM ...

Page 38: ...ence Standard EN 55011 1991 CISPR11 1990 Group 1 Class A Operating Environment Temperature 0ºC to 55ºC Maximum Humidity 95 at 40ºC non condensing Minimum Humidity 15 at 40ºC non condensing Maximum Altitude 3 000 meters 9 840 feet Location For use indoors Storage Conditions Storage Temperature 20ºC to 70ºC Non Operating Maximum Humidity 90 at 65ºC non condensing Non Operating Maximum Altitude 15 24...

Page 39: ...9 0 lb Shipping HP EPM 441A 7 9 Kg 17 4 lb HP EPM 442A 8 0 Kg 17 6 ib Safety Conforms to the following Product Specifications EN61010 1 1993 IEC 1010 1 1990 A1 CSA C22 2 No 1010 1 1993 EN60825 1 1994 IEC 825 1 1993 Class 1 Low Voltage Directive 72 23 EEC Remote Programming Interface HP IB interface operates to IEEE 488 2 Command Language SCPI standard interface commands HP EPM 441A is HP 437B code...

Page 40: ...42A Service Guide HP EPM 441A HP IB Compatibilty SH1 AH1 T6 TE0 L4 LE0 SR1 RL1 PP1 DC1 DT1 C0 Non Volatile Memory Battery Lithium Polycarbon Monoflouride approximate lifetime 5 years at 25ºC 4402serv book Page 16 Monday March 11 2002 11 34 AM ...

Page 41: ...2 Performance Tests 4402serv book Page 1 Monday March 11 2002 11 34 AM ...

Page 42: ...to the interior of the power meter A simpler operational test is included in Self Test of the User s Guide Note For valid performance tests the following conditions must be met a The power meter and test equipment must have a 30 minute warm up for all specifications b The line voltage for the power meter must be 85 to 264 Vac and the line frequency must be 47 to 63 Hz c The ambient temperature mus...

Page 43: ...ts A Adjustments Digital Multimeter HP 3458A Range 0 to 20 V Resolution 0 01 V P and A Range Calibrator HP 11683A Calibration Uncertainty 0 25 P and A Frequency Counter HP 5314A Range 10 Hz to 50 MHz Resolution 1 Hz P and A Power Meter HP 432A Range 1 mW Transfer Accuracy 0 2 P and A Thermistor Mount HP 478A Option H75 HP 478A Option H76 SWR 1 05 at 50 MHz Accuracy 0 5 at 50 MHz P and A Power Sens...

Page 44: ...signed to verify published power meter specifications Perform the tests in the order given and record the data in Table 2 6 on page 2 18 and or in the data spaces provided at the end of each procedure Calibration Cycle This power meter requires periodic verification of performance to ensure that it is operating within specified tolerances The performance tests described in this chapter should be p...

Page 45: ...etup Electrical Characteristics Performance Limits Accuracy Zero set Digital settability of zero 0 0764 µW1 1 This performance limit is determined by the zero set specification of the power sensor used in the measurement plus the measurement noise The range calibrator has a zero set specification of 0 05 µW The calibrator measurement noise specification is 110 nW at 16 averages At 512 averages a n...

Page 46: ...zero value before attempting to zero the power meter This settling would appear on the power meter display as downward drift When the drift has reached minimum typically less than 60 seconds the range calibrator is settled 6 On the power meter press select 512 from the pop up window then press 7 On the power meter press When the wait symbol disappears press Wait approximately 10 seconds for the wa...

Page 47: ...rovide these reference inputs Equipment Range Calibrator HP 11683A Power Sensor Cable HP 11730A Test Setup Figure 2 2 Instrument Accuracy Test Setup Electrical Characteristics Performance Limits Accuracy 0 5 or 0 02 dB 1 1 This performance limit does not include the corresponding sensor power linearity specification HP 11730A POWER METER CHANNEL A Power Meter Range Calibrator 4402serv book Page 7 ...

Page 48: ...tempting to zero the power meter This settling would appear on the power meter display as downward drift When the drift has reached minimum typically less than 60 seconds the range calibrator is settled 6 On the power meter press select 512 from the pop up window then press 7 On the power meter press Wait approximately 10 seconds for the wait symbol to disappear Verify that the display reads 0 0 0...

Page 49: ... of the power sensor used in the measurement plus the measurement noise Channel A Actual Results Channel B Actual Results HP EPM 442A only Max1 3 µW 3 100 µW _______________ _______________ 3 230 µW 10 µW 9 900 µW _______________ _______________ 10 10 µW 30 µW 31 40 µW _______________ _______________ 31 80 µW 100 µW 99 50 µW _______________ _______________ 100 5 µW 300 µW 0 314 µW _______________ ...

Page 50: ...ried out before this verification test is performed the result obtained here will be more accurate The power reference oscillator can be set to 0 7 using the same equipment and following the adjustment procedure To ensure maximum accuracy in verifying the power reference oscillator output the following procedure provides step by step instructions for using specified Hewlett Packard test instrument...

Page 51: ...re V0 is the voltage measured between Vcomp and VRF with no power applied and after the HP 432A has been zeroed V1 is the voltage measured between Vcomp and VRF with power applied This power is approximately 1 mW Vcomp is the voltage between the HP 432A Vcomp connector and chassis ground with power applied R is the resistance of the mount resistor in the HP 432A power meter Calibration Factor is t...

Page 52: ...s ground Note Ensure that the HP 432A and the power meter under test have been powered on for at least 30 minutes before performing the following steps 4 Press on the power meter 5 Set the HP 432A RANGE switch to Coarse Zero Adjust the front panel Course Zero control to obtain a zero meter indication 6 Fine zero the HP 432A on the most sensitive range then set the RANGE switch to 1 mW 7 Set the DV...

Page 53: ...s ground 13 Observe the DVM reading Record the reading as Vcomp Vcomp __________ 14 Calculate the Power Reference Oscillator power using the following equation 15 Verify that Pmeas is within the limits shown in Table 2 4 Record the reading Table 2 4 Power Reference Level Result Min Channel A Actual Result Channel B Actual Result HP EPM 442A Only Max 0 981 mW ________________ ________________ 1 019...

Page 54: ...ter this test should be performed on both channels Procedure 1 When there is no power sensor connected to the Channel A input the message No Sensor No Sensor ChA on the HP EPM 442A appears on the measurement window 2 Connect the HP E series power sensor to the power meter s Channel A input The message Reading Sensor ChA appears When all the data is downloaded this message disappears and a reading ...

Page 55: ...ts The HP E series power sensors operate over a 90 dB dynamic range 70 to 20 dBm However since there is an amplifier in these power sensors the voltages presented to the power sensor connector are always within the range of voltages available from the HP 11683A range calibrator Equipment Power Sensor Cable HP 11730A Reference Attenuator HP 11708A HP E series power sensor 4402serv book Page 15 Mond...

Page 56: ...ect the equipment as shown in Figure 2 4 Figure 2 4 Sensor Functional Test Setup 2 Press 3 On the power meter press Wait approximately 10 seconds for the wait symbol to disappear Verify that the display reads 0 50 pW 4 Press to calibrate the power meter 5 Turn the power reference on by pressing on the HP EPM 441A on the HP EPM 442A Power Meter HP E Series Power Sensor POWER REF CHANNEL A HP 11730A...

Page 57: ...eading 11 Press and set to LOWER 12 Disconnect the 30 dB attenuator and reconnect as shown in Figure 2 4 13 Verify that an overload error is displayed on the status line at the top of the power meter s display 14 Press and set to UPPER 15 Verify that the display reads 0 dBm 1 dB Record the reading Table 2 5 Functional Test Result Test Channel A Overload Error Channel B Overload Error HP EPM 442A O...

Page 58: ...___________ ___________ ___________ ___________ ___________ ___________ ___________ ___________ ___________ ___________ ___________ ___________ ___________ ___________ ___________ ___________ ___________ ___________ ___________ ___________ 3 230 µW 10 10 µW 31 80 µW 100 5 µW 0 318 mW 1 005 mW 3 171 mW 10 08 mW 31 94 mW 101 8 mW Power Reference Pmeas 0 981 mW ___________ ___________ 1 019 mW Interf...

Page 59: ...3 Adjustments 4402serv book Page 1 Monday March 11 2002 11 34 AM ...

Page 60: ...are required Allow 30 minutes for the power meter to warm up and then remove the cover for access to the test and adjustment points To determine which performance tests and adjustments to perform after a repair see Post Repair Adjustments on page 3 3 Safety Considerations This warning must be followed for your protection and to avoid damage to the equipment being used WARNING Adjustments described...

Page 61: ... Performance Tests or Self Tests A1 Power Supply Self Test A2 Processor Assembly Frequency and Level Adjustments Power Reference Level Test Display Brightness and Contrast Adjustment A3 Front Panel Assembly Instrument Accuracy Test Display Brightness and Contrast Adjustment A4 Interface Assembly All automated Tests A5 Daughter Assembly Instrument Accuracy Test A6 Measurement Assembly Zero Test Ins...

Page 62: ...nt on page 3 6 The power reference oscillator frequency is a nominal specification Description Variable inductor A2L9 is adjusted to set the power reference oscillator output frequency to 50 0 0 5 MHz This frequency is a supplemental characteristic Figure 3 1 Adjustment Setup Equipment Frequency Counter HP 5314A Procedure 1 Ensure that the power meter has been powered on for at least 30 minutes be...

Page 63: ...tor frequency is necessary If it is not within these limits adjust the power reference oscillator frequency as described in step 5 and step 6 5 Remove the power meter cover 6 Adjust A2L9 to obtain a 50 0 0 5 MHz indication on the frequency counter Refer to Figure 3 2 for the position of A2L9 Figure 3 2 A2L9 Adjustment Location Zero Cal Power Ref Off On Zero Cal Cal More Power Ref Off On BT1 A2R90 ...

Page 64: ... the power reference oscillator the following procedure provides step by step instructions for using specified Hewlett Packard instruments of known capability If equivalent instruments are used signal acquisition criteria may vary and reference should be made to the manufacturer s guidelines for operating the equipment Note The power meter may be returned to the nearest HP office to have the power...

Page 65: ...ltage measured between Vcomp and VRF with no power applied and after the HP 432A has been zeroed V1 is the voltage measured between Vcomp and VRF with power applied This power is approximately 1 mW Vcomp is the voltage between the HP 432A Vcomp connector and chassis ground with power applied R is the resistance of the mount resistor in the HP 432A power meter Calibration Factor is the value of the...

Page 66: ...e test power meter approximately 200 Ω R Internal Bridge Resistance _______________Ω 3 Connect the equipment as shown in Figure 3 3 The leads should be isolated from ground Ensure that the power reference oscillator is off Ensure that both the power meter under test and the HP 432A have been powered on for at least 30 minutes before proceeding to the next step 4 Set the HP 432A range switch to coa...

Page 67: ... zero switch and adjust the coarse zero control so that the DVM indicates 200 µV or less Then release the fine zero switch and proceed to the next step 9 Round off the DVM reading to the nearest microvolt and record this value as V0 V0________________µV Disconnect the DVM negative input lead from the VRF connector on the test power meter and reconnect it to chassis ground 4402serv book Page 9 Mond...

Page 68: ...2A The DVM is now set up to measure V1 which represents the power reference oscillator output level 13 Calculate the required value of V1 using equation 2 14 Remove the power meter s cover and adjust A2R90 until the DVM indicates the calculated value of V1 Refer to Figure 3 4 for the position of A2R90 Figure 3 4 A2R90 Adjustment Location Zero Cal Power Ref Off On Zero Cal Cal More Power Ref Off On...

Page 69: ...urement uncertainty the significant multimeter uncertainty parameters are for Vcomp V1 V0 and R Other uncertainties which should be included are Maths Assumptions 0 01 Effective Efficiency Calibration 0 05 Mismatch Uncertainty with Source and Mount 0 1 SWR 1 05 These values are typical 4402serv book Page 11 Monday March 11 2002 11 34 AM ...

Page 70: ...y after executing the softkey located under the softkey menu Note The contrast adjustment is subjective and varies according to individual user requirements Procedure 1 Access the softkey menu and use the softkey to increase the contrast or the softkey to decrease the contrast of the display 2 When the desired display contrast level is obtained press the softkey located under the softkey menu Set ...

Page 71: ...4 Theory of Operation 4402serv book Page 1 Monday March 11 2002 11 34 AM ...

Page 72: ...vice Guide Introduction This chapter describes how each of the power meter s assemblies operate A block diagram is included at the end of the chapter giving you an overall view of the power meter s operation 4402serv book Page 2 Monday March 11 2002 11 34 AM ...

Page 73: ...e on the power meter s rear panel HP Part Number 2110 0957 The fuse holder contains a spare fuse as standard on shipment In addition there is also a fuse on the power supply assembly HP Part Number 2110 0957 However a transient suppressor is fitted to the line input module so that any mains transient blows the line module fuse before the power supply fuse If the power supply fuse blows there is a ...

Page 74: ...wer the fan This is filtered to decouple it from the rest of the system The reference oscillator has a 50 MHz oscillator circuit with automatic level control ALC The oscillator output is level detected and that level is compared to a temperature stable precision reference voltage This comparison produces an error signal that gives negative feedback control of the oscillator output power The freque...

Page 75: ... from the microcontroller allows the optimum backlight brightness to be factory set The temperature sense voltage LED current and LCD bias voltage are all measured at self test An analog multiplexer provides means by which several diagnostic points can be switched to the A6 measurement assembly s for analogue to digital conversion The microcontroller uses this function to perform self test A6 meas...

Page 76: ...d distributed to the A4 interface assembly and the A5 daughter assembly The program memory for the microcontroller is FLASH EEPROM to allow for in circuit programming The static RAM is split into volatile and non volatile blocks with the power for the non volatile RAM being connected to the permanent battery backed power supply 4402serv book Page 6 Monday March 11 2002 11 34 AM ...

Page 77: ...ssembly and a sensor cable assembly s There are two inputs to the front panel assembly the flex circuit from connector A2J4 of the processor assembly which controls the keypad the ribbon cable from A2J3 of the processor assembly which controls the LCD display The power meter self tests contain display tests These are accessed by pressing System Inputs More Service Self Test Individual Display 4402...

Page 78: ...th a protocol controller integrated circuit and two physical interface buffers The assembly is connected to data address and control signals from the A2 processor assembly The system clock from the A2 processor assembly is divided by four to provide the HP IB controller integrated circuit s clock signal The interface assembly also provides a filtered path for the recorder output signal 4402serv bo...

Page 79: ...mbly is loaded vertically into the A2 processor assembly It contains two slotted post connectors Depending on whether you have an HP EPM 441A or an HP EPM 442A power meter either one or two of these connectors are used respectively for the A6 measurement assembly s 4402serv book Page 9 Monday March 11 2002 11 34 AM ...

Page 80: ...r sensor produce a feedback amplifier which has a gain of approximately 500 The Feedback line shown sets the gain and also biases the transistor The differential amplifier removes any common mode noise or interference It uses a special ground wire Sensor Ground connected close to the RF bulkhead in the power sensor as it s second input The band pass filter represents the filtering action of the in...

Page 81: ...he power meter s self test of both the measurement assembly and the A2 processor assembly The results are reported back to the A2 processor assembly via the Internal Serial Bus The HP E series power sensors have built in serial EEPROM and range switching which is controlled or accessed via the measurement assembly The N Chop sensor wire used by the HP 8480 series power sensors doubles as a serial ...

Page 82: ...Theory of Operation A6 Measurement Assembly 4 12 HP EPM 441A 442A Service Guide 4402serv book Page 12 Monday March 11 2002 11 34 AM ...

Page 83: ...HP EPM 441A 442A Service Guide Instrument Block Diagram pullout1 fm Page 1 Monday March 11 2002 1 39 PM ...

Page 84: ...Theory of Operation A6 Measurement Assembly 4 14 HP EPM 441A 442A Service Guide 4402serv book Page 14 Monday March 11 2002 11 34 AM ...

Page 85: ...5 Replaceable Parts 4402serv book Page 1 Monday March 11 2002 11 34 AM ...

Page 86: ... be ordered from Hewlett Packard It also details how to assemble and disassemble the power meter for repair To order parts contact your local Hewlett Packard Sales and Service Office To return your power meter for servicing at a qualified service center refer to Contacting Hewlett Packard in Chapter 2 of the User s Guide 4402serv book Page 2 Monday March 11 2002 11 34 AM ...

Page 87: ...9 A303 Front Panel Assembly for HP EPM 442A and HP EPM 442A Option 002 E4419 69019 1 A304 Front Panel Assembly for HP EPM 442A Option 003 E4419 69020 4 A4 Interface Assembly E4418 60004 5 A5 Daughter Assembly for HP EPM 441A E4418 60002 3 Daughter Assembly for HP EPM 442A E4419 60002 4 A6 Measurement Assembly E4418 60003 4 A7 Fan Assembly E4418 61004 7 BT1 Battery 1420 0338 0 MP1 Bail Handle 34401...

Page 88: ...1009 2 W2 Channel B sensor cable Assy HP EPM 442A only E4418 61009 2 W3 Recorder Output Cable Assy E4418 61015 0 Front Power Reference Cable Kit E4418 61811 4 Rear Power Reference Cable Kit E4418 61813 6 Reference Designator Description HP Part Number Check Digit 4402serv book Page 4 Monday March 11 2002 11 34 AM ...

Page 89: ...change assembly However if front panel sensor cables or power reference cables are faulty they should be replaced by ordering the appropriate kit and following the assembly disassembly procedure The instrument accuracy test should then be carried out to verify the functionality of the new part 4402serv book Page 5 Monday March 11 2002 11 34 AM ...

Page 90: ...Unix workstation is also required To determine the firmware version in your power meter press Contact your local Service Center if you require a firmware upgrade Refer to Sales and Service Offices on page ix for details of your local Service Center Downloading Firmware Instrument Firmware should be downloaded after the processor board is replaced Firmware can be accessed by HP Service Centers usin...

Page 91: ...e safety symbols on the power meter and Equipment Operation on page v before operating this power meter with the cover removed Failure to comply with the safety precautions can result in severe or fatal injury WARNING Before carrying out any assembly or disassembly of the power meter ensure that you disconnect the power cord Even with the power meter switched off there are potentially dangerous vo...

Page 92: ...y assembly and lift out the power supply When replacing these screws use a 9 lb in T15 screw driver WARNING When replacing the power supply unit in the power meter ensure that all earth wiring is reconnected There are two terminals to check the first is the force fit connector to the power supply unit itself and the second a closed loop terminal bonded to the chassis with an M3 5 machine screw use...

Page 93: ...upply connector 4 Turn the power meter upside down and remove the three screws as shown When replacing these screws use a 6 lb in T10 screw driver 5 Push the A2 processor assembly towards the front panel to release it from the 50 pin connector Lift it upwards to remove Note When re assembling the processor board ensure the A2 plastic support bracket is returned to its locked position Note After re...

Page 94: ...crew When replacing this screw use a 9 lb in T15 screw driver 4 Remove the two screws on the underside of the deck assembly then remove the assembly by sliding forward and tilting up from the rear When replacing these screws use a 21 lb in T15 screw driver 5 Unscrew the HP IB connector from the rear panel When replacing these screws use a 6 lb in 9 32 in socket 6 Disconnect the Recorder Output cab...

Page 95: ...onnector tab forward and lifting To replace the flex circuit loop it as shown on page 5 16 and connect the flex circuit as shown in the figures below 2 Slide out the measurement assembly from the side of the power meter 3 The daughter assembly is removed vertically A5 A6 1 Connector closed 2 Slide connector clamp in direction of arrow 3 Rotate connector 4 Position sensor flex circuit into connecto...

Page 96: ...e Guide Removing the A7 Fan Assembly 1 Remove the A1 power supply assembly as shown on page 5 8 2 Remove the pins which attach the fan to the chassis 3 Remove the fan cable connector from the A2 processor assembly to release the fan 4402serv book Page 12 Monday March 11 2002 11 34 AM ...

Page 97: ...ery is siliconed to the assembly It may be necessary to remove it using a scalpel 5 Store the battery individually in an anti static dissipative bag or suitable non conductive packaging 6 After replacing the battery secure it using a tie wrap This should be secured from the top of the A2 processor assembly The recommended tie wrap part number is 1400 1154 7 Replace the A2J1 link WARNING This power...

Page 98: ...ould be taken when disconnecting the flex circuit from the measurement assembly The flex circuit assembly is released by pushing the connector tab forward and lifting To replace the flex circuit loop it as shown on page 5 16 and connect the flex circuit as shown in the figures on page 5 11 3 Remove the center screw from the right hand side of the front panel 4 Remove the front panel by pressing in...

Page 99: ...ront Panel Power Sensor Cable Assemblies 1 Remove the front panel from the power meter Refer to Removing the A3 Front Panel Assembly on page 5 14 for details on removing the front panel 2 Replace the power sensor cable assembly s using the replacement kit 4402serv book Page 15 Monday March 11 2002 11 34 AM ...

Page 100: ...Replaceable Parts Assembly and Disassembly Guidelines 5 16 HP EPM 441A 442A Service Guide 4402serv book Page 16 Monday March 11 2002 11 34 AM ...

Page 101: ...ont panel from the power meter Refer to Removing the A3 Front Panel Assembly on page 5 14 for details on removing the front panel 2 Replace the power reference output cable assembly using the replacement kit and the torques indicated on the following diagrams 25 lb in Fold up tab after assembly 9 lb in 6 lb in 4402serv book Page 17 Monday March 11 2002 11 34 AM ...

Page 102: ...r meter to allow access to the rear panel connectors This is done by following steps 1 through 3 of the A4 interface assembly removal procedure on page 5 10 2 Replace the power sensor cable assembly s using the replacement kits The inner recess on the power sensor cable is used to locate the circlip when assembling to the rear chassis 4402serv book Page 18 Monday March 11 2002 11 34 AM ...

Page 103: ...Replaceable Parts Assembly and Disassembly Guidelines HP EPM 441A 442A Service Guide 5 19 4402serv book Page 19 Monday March 11 2002 11 34 AM ...

Page 104: ...n 003 1 Disassemble the power meter down to allow access to the rear panel connectors Refer to Removing the A4 Interface Assembly on page 5 10 2 Replace the power reference cable assembly using the replacement kit and the torques indicated on the following diagrams 25 lb in 6 lb in 9 lb in tie wraps 4402serv book Page 20 Monday March 11 2002 11 34 AM ...

Page 105: ...kage viii connector Recorder Output 1 13 connectors HP IB 1 13 D danger v daughter assembly description 4 9 replacement 5 11 dimensions of instrument 1 15 display resolution specification 1 3 units specification 1 3 documents viii E environmental characteristics 1 14 F fan assembly replacement 5 12 firmware upgrades 5 6 frequency adjustment 3 4 frequency range 1 13 specification 1 3 frequency char...

Page 106: ...ency 3 4 oscillator level adjustment 3 6 specification 1 5 power reference cable replacement 5 17 5 20 power reference level test 2 10 power sensor cable replacement 5 15 5 18 power supply assembly description 4 3 replacement 5 8 processor assembly description 4 4 replacement 5 9 R Recorder Output connector characteristic 1 13 relative accuracy specification 1 4 replace battery 5 13 daughter assem...

Page 107: ...record 2 18 U upgrades 5 6 user s guides viii V voltage 1 13 W warm up 1 2 warning v warranty iii weight of instrument 1 15 Z zero drift definition 1 12 drift of sensors characteristic 1 7 zero set definition 1 12 specification 1 4 zero test 2 5 4402serv book Page 3 Monday March 11 2002 11 34 AM ...

Page 108: ...Index 4 HP EPM 441A 442A Service Guide 4402serv book Page 4 Monday March 11 2002 11 34 AM ...

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