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Errata
This manual may contain references to HP or Hewlett-Packard. Please note that Hewlett-Packard's former test and
measurement, semiconductor products and chemical analysis businesses are now part of Agilent Technologies. To
reduce potential confusion, the only change to product numbers and names has been in the company name prefix: where
a product number/name was HP XXXX the current name/number is now Agilent XXXX. For example, model number
HP8648 is now model number Agilent 8648.
Ce manuel peut contenir des références à <<HP>> ou <<Hewlett-Packard.>> Veuillez noter que les produits de test et
mesure, de semi-conducteur et d'analyse chimique qui avaient fait partie de la société Hewlett-Packard sont maintenent
une partie de la société Agilent Technologies. Pour reduire la confusion potentielle, le seul changement aux noms de
reference a été dans le préfixe de nom de société : là où un nom de référence était HP XXXX, le nouveau nom de
référence est maintenant Agilent XXXX. Par example, le HP 8648 s'appelle maintenent Agilent 8648.
Diese Gebrauchsanweiseung kann Bezug nehmen auf die Namen HP oder Hewlett-Packard. Bitte beachten Sie, dass
ehemalige Betriebsbereiche von Hewlett-Packard wie 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-Packard. Si noti che le attività precedentemente gestite
da Hewlett-Packard nel campo di Test & Misura, Semiconduttori, ed Analisi Chimica sono ora diventate parte di
Agilent Technologies. Al fine di ridurre il rischio di confusione, l'unica modifica effettuata sui numeri di prodotto e sui
nomi ha riguardato il prefisso con il nome dell'azienda : dove precedentemente compariva "HP XXXX" compare ora
"Agilent XXXX". Ad esempio: il modello HP8648 è ora indicato come Agilent 8648.
Este manual puede hacer referencias a HP o Hewlett Packard. Las organizaciones de Prueba y Medición (Test and
Measurement), Semiconductores (Semiconductor Products) y Análisis Químico (Chemical Analysis) que pertenecían a
Hewlett Packard, ahora forman parte de Agilent Technologies. Para reducir una potencial confusión, el único cambio en
el número de producto y nombre, es el prefijo de la compañía: Si el producto solía ser HP XXXX, ahora pasa a ser
Agilent XXXX. Por ejemplo, el modelo HP8648 es ahora Agilent 8648.
Document Part Number 5971-2669
Printed in the UK September 2004
Advanced Test Equipment Rentals
www.atecorp.com 800-404-ATEC (2832)
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Summary of Contents for HP E4418A

  • Page 1 Agilent Technologies. Pour reduire la confusion potentielle, le seul changement aux noms de reference a été dans le préfixe de nom de société : là où un nom de référence était HP XXXX, le nouveau nom de référence est maintenant Agilent XXXX.
  • Page 2 マニュアル・チェンジ 変更 本文中の 「HP ( 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 © Copyright 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. HP EPM-441A/442A Service Guide...
  • Page 5: Legal Information

    For warranty service or repair, this product must be returned to a service facility designated by HP. Buyer shall prepay shipping charges to HP and HP shall pay shipping charges, duties, and taxes for products returned to HP from another country.
  • Page 6 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, WHETHER BASED ON CONTRACT, TORT, OR ANY OTHER LEGAL THEORY.
  • Page 7: Equipment Operation

    For continued protection against fire hazard, replace the line fuse(s) only with fuses of the same type and rating (for example, normal blow, time delay, etc.). The use of other fuses or material is prohibited. HP EPM-441A/442A Service Guide...
  • Page 8: General Safety Considerations

    This terminal is for use where the earthing cannot be assured. At least an 18AWG earthing conductor should be used in such an instance, to ground the instrument to an assured earth terminal. HP EPM-441A/442A Service Guide...
  • Page 9: Iec 1010-1 Compliance

    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. HP EPM-441A/442A Service Guide...
  • Page 10: List Of Related Publications

    List of Related Publications List of Related Publications The HP EPM-441A and HP EPM-442A User’s Guides are also available in the following languages: • English Language User’s Guide - Standard • German Language User’s Guide - Option ABD • Spanish Language User’s Guide - Option ABE •...
  • Page 11: Sales And Service Offices

    Thailand: (66-2) 661 3900 For countries in Asia Pacific not listed contact: Hewlett-Packard Asia Pacific Ltd. 17-21/F Shell Tower, Times Square, 1 Matheson Street, Causeway Bay, Hong Kong tel: (852) 2599 7070 fax: (852) 2506 9285 HP EPM-441A/442A Service Guide...
  • Page 12 Hewlett-Packard Canada Ltd. 5150 Spectrum Way Mississauga, Ontario L4W 5G1 (905) 206 4725 In Europe, Africa 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...
  • Page 13 In any correspondence or telephone conversations, refer to the power meter by its model number (which is on the front panel) and full serial number (which is on the rear panel). With this information, the HP representative can quickly determine whether your unit is still within its warranty period.
  • Page 14: Returning Your Power Meter For Service

    4. Seal the shipping container securely with strong nylon adhesive tape. 5. Mark the shipping container “FRAGILE, HANDLE WITH CARE” to ensure careful handling. 6. Retain copies of all shipping papers. HP EPM-441A/442A Service Guide...
  • Page 15: About This Guide

    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 assemble and disassemble the power meter. HP EPM-441A/442A Service Guide xiii...
  • Page 16 About this Guide HP EPM-441A/442A Service Guide...
  • Page 17: Table Of Contents

    Environmental Characteristics ............ 1-14 General Conditions..............1-14 Operating Environment ............1-14 Storage Conditions ..............1-14 General ..................1-15 Dimensions ................1-15 Weight ..................1-15 Safety ..................1-15 Remote Programming ............1-15 Non-Volatile Memory ............. 1-16 HP EPM-441A/442A Service Guide Contents-1...
  • Page 18 Power 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 ................
  • Page 19 Replacing the Front Panel Power Reference Cable Assembly ................. 5-17 Replacing the Rear Panel Power Sensor Cable Assemblies (Options 002 and 003)......... 5-18 Replacing the Rear Panel Power Reference Cable Assembly (Option 003) ............5-20 HP EPM-441A/442A Service Guide Contents-3...
  • Page 20: Hp Epm-441A/442A Service Guide

    Contents-4 HP EPM-441A/442A Service Guide...
  • Page 21: List Of Figures

    Power Reference Level Test Setup ........... 2-11 Sensor Functional Test Setup ........... 2-16 Sensor Functional Test Setup with Attenuator ....... 2-17 Adjustment Setup ..............3-4 A2L9 Adjustment Location ............3-5 Adjustment Setup ..............3-6 A2R90 Adjustment Location ............. 3-10 HP EPM-441A/442A Service Guide Contents-5...
  • Page 22: Hp Epm-441A/442A Service Guide

    Contents-6 HP EPM-441A/442A Service Guide...
  • Page 23: List Of Tables

    Required Equipment ..............2-3 Zero Test Results ............... 2-6 Instrument Accuracy Results............ 2-9 Power Reference Level Result........... 2-13 Functional Test Result .............. 2-17 Performance Test Record ............2-18 Post Repair Adjustments, Tests, and Checks ......3-3 HP EPM-441A/442A Service Guide Contents-7...
  • Page 24 Contents-8 HP EPM-441A/442A Service Guide...
  • Page 25: Specifications

    Specifications...
  • Page 26: Introduction

    These characteristics are shown in italics or denoted as “typical”, “nominal” or “approximate”. For information on measurement uncertainty calculations, refer to HP Application Note 64-1A, “Fundamentals of RF and Microwave Power Measurements”, Literature Number 5965-6630. HP EPM-441A/442A Service Guide...
  • Page 27: Power Meter Specifications

    Power Range -70 dBm to +44 dBm (100 pW to 25 W), power sensor dependent Power Sensors Compatible with all HP 8480 series power sensors and HP ECP-series power sensors. Single Sensor Dynamic Range 90 dB maximum (HP ECP-series power sensors)
  • Page 28: Accuracy

    Zero 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.
  • Page 29: Power Reference

    Power Meter Specifications 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. HP EPM-441A/442A Service Guide...
  • Page 30: Power Meter Supplemental Characteristics

    50 MHz nominal 1.05 maximum Connector Type 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 •...
  • Page 31: Zero Drift Of Sensors

    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...
  • Page 32: Power Sensor Specifications

    2. The number of averages at 16 (for normal mode) and 32 (for x2 mode), at a constant temperature, measured over a 1 minute interval and 2 standard deviations. 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.
  • Page 33: Settling Time

    Specifications Power Meter Supplemental Characteristics Settling Time 0 to 99% settled readings over the HP-IB. For HP 8480 series power sensors Manual filter, 10 dB decreasing power step: Table 1-4: Settling Time Number of 1024 Averages Settling Time (s) 0.15...
  • Page 34: Settling Time

    When a decreasing power 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...
  • Page 35 Settling Dynamic Dynamic Times Times Range Range 120 ms 70 ms 10 dB 10 dB 400 ms 210 ms 10 dB 10 dB 6.5 s 3.4 s 10 dB 10 dB Minimum dBm Minimum dBm HP EPM-441A/442A Service Guide 1-11...
  • Page 36: Power Sensor Specifications

    This parameter is also known as short term stability and is specified as the change in the power meter indication over a short time interval (usually one minute) for a constant input power at a constant temperature. 1-12 HP EPM-441A/442A Service Guide...
  • Page 37: General Characteristics

    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) HP EPM-441A/442A Service Guide 1-13...
  • Page 38: Environmental Characteristics

    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 15,240 meters (50,000 feet) 1-14 HP EPM-441A/442A Service Guide...
  • Page 39: General

    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 compatible. HP EPM-441A/442A Service Guide 1-15...
  • Page 40: Non-Volatile Memory

    Specifications General 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. 1-16 HP EPM-441A/442A Service Guide...
  • Page 41: Performance Tests

    Performance Tests...
  • Page 42: Introduction

    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 must be 0 to 55 HP EPM-441A/442A Service Guide...
  • Page 43: Equipment Required

    Option H75 HP 478A Option H76 Power Sensor HP E-series power sensor 30 dB Attenuator HP 11807A HP 8491A Option 030 Power Sensor Cable HP 11730A P and A 1. P = Performance Tests, A = Adjustments HP EPM-441A/442A Service Guide...
  • Page 44: Performance Test Record

    Equipment settings, other than those for the power meter, are stated in general terms. It is assumed that the person will select the proper cables, adapters, and probes required for test setups illustrated in this chapter. HP EPM-441A/442A Service Guide...
  • Page 45: Zero Test

    This test also takes drift and noise into account, since drift, noise and zero readings cannot be separated. Equipment Range Calibrator ........HP 11683A Power Sensor Cable ......HP 11730A Test Setup Power Meter Range Calibrator...
  • Page 46: Procedure

    The following procedure should be performed for the Zero Test. Note The procedure details the key presses required on the HP EPM-441A. For the HP EPM-442A the equivalent key presses should be performed on both channels. 1. Connect the equipment as shown in Figure 2-1.
  • Page 47: Instrument Accuracy Test

    Description The power meter accuracy is verified for various power inputs. The range calibrator is switched to provide these reference inputs. Equipment Range Calibrator ........HP 11683A Power Sensor Cable ......HP 11730A Test Setup Power Meter Range Calibrator CHANNEL A...
  • Page 48: Procedure

    Test. Note The procedure details the key presses required on the HP EPM-441A. For the HP EPM-442A the equivalent key presses should be performed on both channels. 1. Connect the equipment as shown in Figure 2-2. 2. Switch the power meter on.
  • Page 49: Instrument Accuracy Results

    3.156 mW, 10.03 mW, 31.78 mW, and 101.3 mW respectively. It is not necessary to check instrument accuracy in dBm. The Note power meter uses the same internal circuitry to measure power and mathematically converts watts to dBm. HP EPM-441A/442A Service Guide...
  • Page 50: Power Reference Level Test

    Hewlett-Packard test instruments of known capability. If equivalent test instruments are used, signal acquisition criteria may vary and reference should be made to the manufacturer’s guidelines for operating the instruments. 2-10 HP EPM-441A/442A Service Guide...
  • Page 51: Equipment

    • R is the resistance of the mount resistor in the HP 432A power meter. • Calibration Factor is the value of the thermistor mount at 50 MHz. HP EPM-441A/442A Service Guide...
  • Page 52 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.
  • Page 53: Power Reference Level Result

    V ___________ 12. Disconnect the DVM negative input lead from the V connector on the HP 432A. Reconnect it to the HP 432A chassis ground. 13. Observe the DVM reading. Record the reading as V comp __________ comp 14.
  • Page 54: Hp E-Series Power Sensor Interface Test

    HP E-Series Power Sensor Interface Test HP E-Series Power Sensor Interface Test The HP E-series power sensors have their sensor calibration tables stored in EEPROM which enables the frequency and calibration factor data to be downloaded automatically by the power meter. The frequency and calibration factor data have checksums which are compared with the data downloaded by the power meter.
  • Page 55: Hp E-Series Power Sensor Functional Test

    This test verifies that the meter/sensor combination can make RF measurements. 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.
  • Page 56: Procedure

    To complete the Functional Test the following procedure should be performed. Note The procedure details the key presses required on the HP EPM-441A. For the HP EPM-442A the equivalent key presses should be performed on both channels. 1. Connect the equipment as shown in Figure 2-4. Power Meter...
  • Page 57: Sensor Functional Test Setup With Attenuator

    Performance Tests HP E-Series Power Sensor Functional Test 6. Connect the 30 dB attenuator as shown in Figure 2-5. Power Meter HP E-Series Power Sensor HP 11708A 30 dB ATTENUATOR CHANNEL A HP 11730A Figure 2-5: Sensor Functional Test Setup with Attenuator System 7.
  • Page 58: Performance Test Record

    Performance Tests Performance Test Record Performance Test Record Model HP EPM-441A/442A Power Meter Tested by ___________________________________________ Serial Number _______________________________________ Date _______________ Table 2-6: Performance Test Record Channel A Channel B Test Min Result Actual Actual Result Result Result − 76.40 nW + 76.40 nW...
  • Page 59: Adjustments

    Adjustments...
  • Page 60: Introduction

    Maintenance should be performed only by trained personnel who are aware of the hazards involved. When the maintenance procedure can be performed without power, the power should be removed. HP EPM-441A/442A Service Guide...
  • Page 61: Equipment Required

    A5 Daughter Assembly Instrument Accuracy Test A6 Measurement Assembly Zero Test, Instrument Accuracy Test W1 or W2 Power Sensor Instrument Accuracy Test, Zero Test Cable BT1 Battery Battery Self Test Power Reference Cable Kits Power Reference Level Test HP EPM-441A/442A Service Guide...
  • Page 62: Power Reference Oscillator Frequency Adjustment

    Frequency Counter POWER 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 before making any measurements. 2. Connect the equipment as shown in Figure 3-1. Set up the counter to measure frequency.
  • Page 63: A2L9 Adjustment Location

    Adjustments Power Reference Oscillator Frequency Adjustment 3. Turn the power reference on by pressing Zero on the HP EPM-441A. Power Ref Off On Zero on the More Power Ref Off On HP EPM-442A. 4. Observe the reading on the frequency counter. If it is 50.0 ±...
  • Page 64: Power Reference Oscillator Level Adjustment

    If equivalent instruments are used, signal acquisition criteria may vary and reference should be made to the manufacturer’s guidelines for operating the equipment. The power meter may be returned to the nearest HP office to have Note the power reference oscillator checked and/or adjusted.
  • Page 65 • R is the resistance of the mount resistor in the HP 432A power meter. • Calibration Factor is the value of the thermistor mount at 50 MHz. HP EPM-441A/442A Service Guide...
  • Page 66: Equipment

    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 coarse zero and adjust the front panel coarse zero control to obtain a zero meter indication.
  • Page 67 8. Observe the reading on the DVM. If less than 400 µ V, proceed with the next step. If 400 µ V or greater, press and hold the HP 432A fine zero switch and adjust the coarse zero control so that the DVM indicates 200 µ...
  • Page 68: A2R90 Adjustment Location

    12. Reconnect the negative lead to the V connector on the rear panel of the HP 432A. The DVM is now set up to measure V which represents the power reference oscillator output level. 13. Calculate the required value of V using equation 2.
  • Page 69: Measurement Uncertainty

    R. Other uncertainties comp 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. HP EPM-441A/442A Service Guide 3-11...
  • Page 70: Display Brightness And Contrast Adjustment

    Display 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 Set Contrast Service menu. 3-12 HP EPM-441A/442A Service Guide...
  • Page 71: Theory Of Operation

    Theory of Operation...
  • Page 72: Introduction

    Theory of Operation Introduction 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. HP EPM-441A/442A Service Guide...
  • Page 73: A1 Power Supply

    (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.
  • Page 74: A2 Processor Assembly

    Circuitry for the keyboard driver includes some damage protection, but it is basically a direct connection from the keypad row and column matrix to the microcontroller’s control lines. Three LEDs on the front panel are illuminated under the following conditions: HP EPM-441A/442A Service Guide...
  • Page 75 The microcontroller circuits that control all the above functions, and provide platform for the system software to run on, comprise the microcontroller itself, memory, and clock and logic circuits. The logic circuits have the function of ensuring the correct sequencing and decoding HP EPM-441A/442A Service Guide...
  • Page 76 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. HP EPM-441A/442A Service Guide...
  • Page 77: A3 Front Panel Assembly

    • 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 System pressing Service Self Test Individual More Inputs Display HP EPM-441A/442A Service Guide...
  • Page 78: A4 Interface Assembly

    A4 Interface Assembly The interface assembly contains the circuitry required for remote control of the power meter. This assembly supports the HP-IB interface with 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.
  • Page 79: A5 Daughter Assembly

    The daughter assembly 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).
  • Page 80: A6 Measurement Assembly

    The measurement assembly amplifies and converts the chopped AC signal produced by the power sensor (either HP 8480 series power sensors or HP E-series power sensors) into a 32 bit digital word. This digital word is proportional to the input RF power level applied to the power sensor. The measurement assembly also measures the sensor resistor voltage to detect whether a power sensor is present.
  • Page 81 The DSP chip controls the logic which sets the chopper driver voltage and frequency control. For the: • HP 8480 series power sensors this is 0 V and -10 V at 217 Hz. • HP E-series power sensors this is +7 V and -3 V at 434 Hz.
  • Page 82 Theory of Operation A6 Measurement Assembly 4-12 HP EPM-441A/442A Service Guide...
  • Page 83 Instrument Block Diagram HP EPM-441A/442A Service Guide...
  • Page 84 Theory of Operation A6 Measurement Assembly 4-14 HP EPM-441A/442A Service Guide...
  • Page 85: Replaceable Parts

    Replaceable Parts...
  • Page 86: Introduction

    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. HP EPM-441A/442A Service Guide...
  • Page 87: Assembly Part Numbers

    Digit Power Supply Assembly 0950-2649 Processor Assembly E4418-60001 A301 Front Panel Assembly for: E4418-69017 HP EPM-441A and HP EPM-441A Option 002 A302 Front Panel Assembly for: E4418-69018 HP EPM-441A Option 003 A303 Front Panel Assembly for: E4419-69019 HP EPM-442A and...
  • Page 88 Description Designator Number Digit Channel A sensor cable Assy E4418-61009 Channel B sensor cable Assy E4418-61009 (HP EPM-442A only) Recorder Output Cable Assy E4418-61015 Front Power Reference Cable Kit E4418-61811 Rear Power Reference Cable Kit E4418-61813 HP EPM-441A/442A Service Guide...
  • Page 89: Front Panel Connector Repair

    The instrument accuracy test should then be carried out to verify the functionality of the new part. HP EPM-441A/442A Service Guide...
  • Page 90: Firmware Upgrades

    The power meter’s firmware can be upgraded using a 300 or 700 series Unix workstation or a PC. The current version of firmware can be accessed by HP Service Centers using the World Wide Web. An executable file on the Unix workstation is also required.
  • Page 91: Assembly And Disassembly Guidelines

    Assembly and Disassembly Guidelines The guidelines in this section describe the removal and replacement of the major assemblies in the HP EPM-441A and HP EPM-442A power meters. Once an assembly has been replaced, refer to “Post-Repair Adjustments”, on page 3-3 to ensure that the correct performance tests and adjustments are carried out.
  • Page 92: Removing The A1 Power Supply Assembly

    M3.5 machine screw (use a 9 lb/in T15 screw driver). All the protective earth wiring can be identified by the insulation color green with a yellow stripe. HP EPM-441A/442A Service Guide...
  • Page 93: Removing The A2 Processor Assembly

    After replacing a processor board, the display brightness and contrast must be adjusted. See Chapter 3 “Adjustments”. Note Firmware should be downloaded to the instrument after the processor board is replaced. Refer to “Downloading Firmware”, on page 5-6. HP EPM-441A/442A Service Guide...
  • Page 94: Removing The A4 Interface Assembly

    (When replacing these screws use a 21 lb/in T15 screw driver.) screws 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 cable.
  • Page 95: Removing The A5 Daughter Or A6 Measurement Assemblies

    2. Slide connector clamp in direction of arrow 3. Rotate connector clamp in direction of arrow 4. Position sensor flex circuit into connector in direction of arrow 6. Push clamp closed in direction of arrow HP EPM-441A/442A Service Guide 5-11...
  • Page 96: 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. 5-12 HP EPM-441A/442A Service Guide...
  • Page 97: Removing The Power Meter Battery (Bt1)

    The battery should not be subjected to short circuit of the battery terminals or to excessive heat. Do not recharge this battery or dispose of it by burning. Check local country regulatory requirements on the disposal of lithium batteries. HP EPM-441A/442A Service Guide 5-13...
  • Page 98: Removing The A3 Front Panel Assembly

    Note After replacing a front panel assembly, the display brightness and contrast must be adjusted. Refer to Chapter 3 “Adjustments”. 5-14 HP EPM-441A/442A Service Guide...
  • Page 99 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. HP EPM-441A/442A Service Guide 5-15...
  • Page 100 Replaceable Parts Assembly and Disassembly Guidelines 5-16 HP EPM-441A/442A Service Guide...
  • Page 101: Replacing The Front Panel Power Reference Cable Assembly

    2. Replace the power reference output cable assembly using the replacement kit and the torques indicated on the following diagrams. Fold up tab after assembly 25 lb/in 9 lb/in 6 lb/in HP EPM-441A/442A Service Guide 5-17...
  • Page 102: Replacing The Rear Panel Power Sensor Cable Assemblies (Options 002 And 003)

    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. 5-18 HP EPM-441A/442A Service Guide...
  • Page 103 Replaceable Parts Assembly and Disassembly Guidelines HP EPM-441A/442A Service Guide 5-19...
  • Page 104: Replacing The Rear Panel Power Reference Cable Assembly (Option 003)

    (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 tie wraps 6 lb/in 9 lb/in 5-20 HP EPM-441A/442A Service Guide...
  • Page 105 3-6 front panel repair 5-5 altitude characteristic 1-14 assembly part numbers 5-3 Hewlett-Packard offices ix battery replacement 5-13 HP E-series power sensor functional test 2-15 calibration cycle 2-4 interface test 2-14 caution v HP-IB characteristics 1-2 connector characteristic 1-13...
  • Page 106 5-8 performance test record 2-18 processor assembly 5-9 performance tests 2-2 replaceable parts 5-2 HP E-series power sensor functional test 2-15 returning for service xii HP E-series power sensor interface test 2-14 instrument accuracy test 2-7 power reference...
  • Page 107 5-6 user’s guides viii voltage 1-13 warm-up 1-2 warning v warranty iii weight of instrument 1-15 zero drift definition 1-12 drift of sensors, characteristic 1-7 zero set definition 1-12 specification 1-4 zero test 2-5 HP EPM-441A/442A Service Guide Index-3...
  • Page 108 Index-4 HP EPM-441A/442A Service Guide...

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E4419a

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