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The Technician's EMI Handbook

Book Description

A hands-on guide to finding the sources of electromagnetic interference and then fixing the problems. Includes basic theory of EMI as well as detailed explanations of why this problem is becoming more serious as the international scope of the communications and electronics industries grow. This book is not a textbook, but rather a handbook that will become a constant source of reference for anyone who runs into trouble with EMI. Includes chapters on grounding, circuit shielding and filtering, preventing EMI in circuit design, as well as EMI sources such as power lines, transmitters, television, consumer electronics, telephones, automobiles, and the ever-frustrating mystery EMI.


There are very few other books available even though EMI is constantly discussed and cursed. Most of the books on the market are about how to prevent EMI in circuit design or approaches to understanding the theory behind EMI. Though this information is important, especially to an engineering audience, these books hold no value at all to the technicians and hands-on practitioners in the fields of communications and servicing.These savvy professionals know that the book they are looking for and need is just not on the market. To get the information they need, this group is forced to read every magazine article they can find on the subject and rely on the advice of other professionals whether through technician groups or newsgroups. This book fills a void in the telecommunications and electronics industries by providing practical troubleshooting information.


Addresses the technician's needs and interests
Written by an eminent authority in the field
Covers correction and prevention of problems with EMI

Table of Contents

  1. Cover image
  2. Title page
  3. Table of Contents
  4. Copyright
  5. Preface
  6. Chapter 1: Introduction to the EMI Problem
  7. Chapter 2: Electrical and Electromagnetic Fundamentals
    1. WHAT IS ELECTRICITY?
    2. POSITIVE AND NEGATIVE ELECTRICITY
    3. ELECTRONIC MODEL OF THE ATOM
    4. THE BOHR MODEL OF THE ATOM
    5. ELECTRON SHELLS
    6. ELECTRON SUBSHELLS AND ELECTRON SPIN
    7. ELECTRON VALENCE AND FREE ELECTRONS
    8. CONDUCTORS, INSULATORS, AND SEMICONDUCTORS
    9. THE UNIT OF ELECTRIC CHARGE
    10. ELECTRICAL POLARITIES
    11. MILLIKAN’S OIL DROP EXPERIMENT
    12. ELECTRICAL POTENTIAL
    13. ELECTRICAL CURRENT AND ITS UNITS
    14. ELECTRICAL CURRENT VS ELECTRICAL CHARGE
    15. TYPES OF CURRENT FLOW
    16. RESISTANCE TO ELECTRICAL CURRENT
    17. CONDUCTANCE
    18. CURRENT FLOW DIRECTION
    19. ELECTRICAL POWER
    20. ELECTRICAL SOURCES
    21. THE ELECTROMAGNETIC FIELD
    22. SOURCES OF ELECTROMAGNETIC INTERFERENCE
  8. Chapter 3: Fundamentals of Electromagnetic Interference
    1. FUNDAMENTAL CAUSES OF EMI
    2. THE ANTENNA
    3. MODES OF ENTRY
    4. DIFFERENTIAL-MODE VS COMMON-MODE SIGNALS
    5. EQUIPMENT DESIGN CONSIDERATIONS
    6. RADIO-FREQUENCY RADIATION
    7. NEAR FIELDS AND FAR FIELDS
  9. Chapter 4: Grounding Methods for RF Systems
    1. SCHEMATIC SYMBOLS
    2. DIFFERENT GROUNDS
    3. GROUNDING SYSTEMS
    4. GROUND DESIGNS
    5. Multiple Ground Rod Systems
    6. OTHER GROUND ELECTRODES
    7. Electrolytic Grounding Systems
    8. INSTALLING GROUND RODS
    9. TOWER GROUNDING
    10. VERTICAL ANTENNA COUNTERPOISE GROUNDS (“RADIALS”)
    11. CONCLUSION
  10. Chapter 5: Shielding Electronic Circuits
    1. APPROACHES TO SHIELDING
    2. SKIN EFFECT AND SKIN DEPTH
    3. GROUND PLANES
    4. SHIELDED BOXES
    5. HOLES IN SHIELDS
    6. DOUBLE SHIELDING
    7. MULTICOMPARTMENT SHIELDING
    8. SPRAY-ON SHIELDING
    9. CONNECTORS, METERS, AND DIALS
    10. INSTALLING A COAXIAL CONNECTOR
    11. GUARD SHIELDING
    12. GROUNDING AND GROUND LOOPS
  11. Chapter 6: Filtering Electronic Circuits
    1. SHIELDING
    2. BASIC TYPES OF FILTERS
    3. FILTER CIRCUITS
    4. R-C EMI/RFI PROTECTION
    5. FEEDTHROUGH CAPACITORS
    6. NOTCH FILTERING
    7. TWIN-TEE NOTCH FILTER NETWORKS
    8. ACTIVE TWIN-TEE NOTCH FILTERS
    9. ADJUSTABLE BRIDGED-TEE CIRCUITS
    10. GYRATOR CIRCUITS
    11. GENERAL GUIDELINES
    12. CONCLUSION
  12. Chapter 7: AC Power-Line and Electrical Device EMI
    1. 120/240 VOLT ELECTRICAL SYSTEM
    2. NOISE
    3. REGULATORY/LEGAL ISSUES
    4. CORONA AND SPARK
    5. SAFETY
    6. LOCATING EMI SOURCES
    7. FILTER SOLUTION
    8. ELECTRIC MOTORS
    9. COMMON-MODE FILTERING
  13. Chapter 8: Controlling Transmitter Spurious Emissions
    1. TYPES OF TRANSMITTER
    2. OPERATING THE TRANSMITTER
    3. WHAT TO DO?
    4. BE WARY!
    5. TRANSMITTER TEST SETUP
    6. THIRD-HARMONIC OR HIGHER
    7. VHF AND UP TRANSMITTERS
  14. Chapter 9: Telephones and EMI
    1. THE FEDERAL COMMUNICATIONS COMMISSION
    2. THE TELEPHONE COMPANY
    3. THE RADIO OWNER
    4. THE TELEPHONE MANUFACTURER
    5. THE TELEPHONE OWNER
    6. TECHNICAL ISSUES
    7. TWISTED PAIR, FLAT (PARALLEL), AND SHIELDED WIRING
    8. COMMON MODE VS DIFFERENTIAL MODE
    9. RESONANCES
    10. TELEPHONE GROUND
    11. CORROSION
    12. SUBSTANDARD WIRING
    13. TELEPHONE CLASSIFICATION
    14. TELEPHONE REGISTRATION NUMBERS
    15. CAPACITORS
    16. COMMON-MODE RF CHOKES
    17. FILTERING
    18. FEDERAL COMMUNICATIONS COMMISSION COMPLIANCE & INFORMATION BUREAU
    19. SOURCES OF RADIO-PROOF TELEPHONES AND RADIO FILTERS FOR TELEPHONES
  15. Chapter 10: Noise Cancellation Bridges
    1. A SIMPLE BRIDGE CIRCUIT
    2. A DIFFERENT BRIDGE
    3. CONCLUSION
  16. Chapter 11: Locating EMI Sources
    1. RF SLEUTHING TOOLS
    2. RF DETECTORS
    3. RADIO DIRECTION FINDING
    4. FIELD IMPROVISATION
    5. REGULAR LOOP ANTENNAS
    6. SENSE ANTENNA CIRCUIT
    7. SWITCHED PATTERN RDF ANTENNAS
  17. Chapter 12: EMI to Television, Cable TV, and VCR Equipment
    1. THE BASIC TELEVISION RECEIVER
    2. FUNDAMENTAL OVERLOAD
    3. HARMONIC OVERLOAD
    4. AUDIO RECTIFICATION
    5. IMD INTERFERENCE
    6. IF INTERFERENCE
    7. DIRECT PICKUP
    8. COMMON-MODE VS DIFFERENTIAL-MODE SIGNALS
    9. COMMON-MODE FILTERS
    10. FILTERING
    11. STUBS FOR EMI ELIMINATION
    12. FARADAY SHIELDED COAXIAL CABLE
    13. CABLE TELEVISION SYSTEMS
    14. TWO-WAY CATV
    15. CHANNELIZATION
    16. LEAKAGE
    17. RESPONSIBILITY
    18. FINDING LEAKS
    19. WHAT TO DO WHEN THE INTERFERENCE IS AT THE SUBSCRIBER END
    20. WHAT TO DO WHEN THE CUSTOMER IS AT FAULT
    21. VCRS
  18. Chapter 13: EMI to Consumer Electronics
    1. ROLES AND RESPONSIBILITIES
    2. THE SOURCE OF THE PROBLEM
    3. TYPICAL AUDIO SYSTEM
    4. PATHWAYS FOR TROUBLE
    5. TROUBLESHOOTING
    6. CURES
    7. SHIELDING
    8. GROUNDING
  19. Chapter 14: EMI from Computers
    1. THE LAW
    2. THE PROBLEMS WITH COMPUTERS
    3. CABINETRY
    4. TROUBLESHOOTING COMPUTER EMI
    5. THE ROLE OF FERRITE CHOKES
    6. GROUND LOOPS
    7. EMI TO COMPUTERS
  20. Chapter 15: Mystery EMI: Rusty Downspouts and All That
    1. MOODIE AND THE CROWN VICKIE
    2. THE HIGH HUM LEVEL—FM BROADCASTING STATION
    3. THE SLACK COAX CAPER
    4. LESSON LEARNED: DON’T COMPLAIN TOO LOUDLY
    5. RUSTY DOWNSPOUTS
  21. Chapter 16: Radio Receiver Basics
    1. SIGNALS, NOISE, AND RECEPTION
    2. THERMAL NOISE
    3. THE RECEPTION PROBLEM
    4. STRATEGIES
    5. RADIO RECEIVER SPECIFICATIONS
    6. ORIGINS
    7. SUPERHETERODYNE RECEIVERS
    8. RECEIVER PERFORMANCE FACTORS
    9. UNITS OF MEASURE
    10. dBm
    11. dBmV
    12. dBμV
    13. RULE OF THUMB: To convert dBμV to dBm, subtract 113 dB; le., 100 dBμV = (100 dBμV-113 dB) = −13 dBm.
    14. NOISE
    15. SIGNAL-TO-NOISE RATIO (SNR OR Sn)
    16. NOISE FACTOR, NOISE FIGURE, AND NOISE TEMPERATURE
    17. Noise Factor (Fn)
    18. Noise Temperature (Te)
    19. NOISE IN CASCADE AMPLIFIERS
    20. RECEIVER NOISE FLOOR
    21. STATIC MEASURES OF RECEIVER PERFORMANCE
    22. SENSITIVITY
    23. SELECTIVITY
    24. IF Bandwidth
    25. IF Passband Shape Factor
    26. STABILITY
    27. AGC RANGE AND THRESHOLD
    28. DYNAMIC PERFORMANCE
    29. INTERMODULATION PRODUCTS
    30. −1 dB COMPRESSION POINT
    31. THIRD-ORDER INTERCEPT POINT
    32. DYNAMIC RANGE
    33. BLOCKING
    34. CROSS-MODULATION
    35. RECIPROCAL MIXING
    36. IF NOTCH REJECTION
    37. INTERNAL SPURII
  22. Chapter 17: Dealing with Radio Receiver System EMI
    1. INTERMOD HILL: A TALE OF WOE
    2. THE PROBLEM
    3. THE ATTENUATOR SOLUTION
    4. THE ANTENNA SOLUTION
    5. THE FILTER SOLUTION
    6. TRANSMISSION LINE STUBS
    7. SHIELDING
    8. EXPECTED RESULTS
    9. DIFFICULT CASES
    10. THE SOLUTIONS
  23. Chapter 18: Electrostatic Discharge (ESD)
    1. ESD EFFECTS
    2. IDENTIFICATION BY CLASS
    3. ESD CONTROL PROCEDURES
    4. WORK AREAS
    5. PROTECTIVE FLOORING
    6. WORKBENCHES
    7. EQUIPMENT
    8. CLOTHING
    9. ESD-PROTECTIVE MATERIALS
  24. Chapter 19: Regulatory Issues
    1. ANECHOIC CHAMBERS AND OATS
    2. SCREENED ROOMS
  25. Appendix A: Automotive Interference Solutions
  26. Appendix B: FDA Documents on EMI
  27. Index