CHAPTER HEADINGS PREFACE & ACKNOWLEDGEMENTS PART 1: THE RADIO VALVE CHAPTER
PAGE
1 INTRODUCTION TO THE RADIO VALVE 2 VALVE CHARACTERISTICS 3 THE TESTING OF OXIDE-COATED CATHODE HIGH-VACUUM RECEIVING VALVES
1 13 68
4 5 6 7 8 9 10 11
PART 2: GENERAL THEORY AND COMPONENTS THEORY OF NETWORKS TRANSFORMERS AND IRON-CORED INDUCTORS MATHEMATICS NEGATIVE FEEDBACK WAVE MOTION AND THE THEORY OF MODULATION TUNED CIRCUITS CALCULATION OF INDUCTANCE DESIGN OF RADIO FREQUENCY INDUCTORS
128 199 254 306 403 407 429 450
12 13 14 15 16 17 18 19 20 21
PART 3: AUDIO FREQUENCIES AUDIO FREQUENCY VOLTAGE AMPLIFIERS AUDIO FREQUENCY POWER AMPLIFIERS FIDELITY AND DISTORTION TONE COMPENSATION AND TONE CONTROL VOLUME EXPANSION, COMPRESSION AND LIMITING REPRODUCTION FROM RECORDS MICROPHONES, PRE-AMPLIFIERS, ATTENUATORS AND MIXERS UNITS FOR THE MEASUREMENT OF GAIN AND NOISE LOUDSPEAKERS THE NETWORK BETWEEN THE POWER OUTPUT STAGE AND THE LOUDSPEAKER
481 544 603 635 679 701 775 806 831 880
22 23 24 25 26 27 28 29
PART 4: RADIO FREQUENCIES AERIALS AND TRANSMISSION LINES RADIO FREQUENCY AMPLIFIERS OSCILLATORS FREQUENCY CONVERSION AND TRACKING INTERMEDIATE FREQUENCY AMPLIFIERS DETECTION AND AUTOMATIC VOLUME CONTROL REFLEX AMPLIFIERS LIMITERS AND AUTOMATIC FREQUENCY CONTROL
890 912 947 962 1020 1072 1140 1147
30 31 32 33
PART 5: RECTIFICATION, REGULATION, FILTERING AND HUM RECTIFICATION FILTERING AND HUM VIBRATOR POWER SUPPLIES CURRENT AND VOLTAGE REGULATORS
1161 1192 1202 1213
34 35 36 37
PART 6: COMPLETE RECEIVERS TYPES OF A-M RECEIVERS DESIGN OF SUPERHETERODYNE A-M RECEIVERS DESIGN OF F-M RECEIVERS RECEIVER AND AMPLIFIER TESTS AND MEASUREMENTS
1223 1228 1287 1297
PART 7: SUNDRY DATA 38 TABLES, CHARTS AND SUNDRY DATA See next page for detailed List of Contents. SUPPLEMENT INDEX
1328 1475 1433
(ix)
CONTENTS PART 1 : THE RADIO VALVE CHAPTER 1. INTRODUCTION TO THE RADIO VALVE SECTION
PAGE
1. ELECTRICITY AND EMISSION 2. THE COMPONENT PARTS OF RADIO VALVES (i) Filaments, cathodes and heaters (ii) Grids (iii) Plates (iv) Bulbs (v) Voltages with valve operation 3. TYPES OF RADIO VALVES (i) Diodes (ii) Triodes (iii) Tetrodes (iv) Pentodes (v) Pentode power amplifiers (vi) Combined valves (vii) Pentagrid converters 4. MAXIMUM RATINGS AND TOLERANCES (i) Maximum ratings and their interpretation (ii) Tolerances 5. FILAMENT AND HEATER VOLTAGE/CURRENT CHARACTERISTICS 6. VALVE NUMBERING SYSTEMS 7. REFERENCES
1 4 4 5 5 5 5 6 6 7 7 7 8 8 8 9 9 9 10 10 12
CHAPTER 2. VALVE CHARACTERISTICS 1. VALVE COEFFICIENTS 2. CHARACTERISTIC CURVES (i) Plate characteristics (ii) Mutual characteristics (iii) Grid current characteristics (iv) Suppressor characteristics (v) Constant current curves (vi) "G" curves (vii) Drift of characteristics during life (viii) Effect of heater-voltage variation 3. RESISTANCE-LOADED AMPLIFIERS (i) Triodes (ii) Pentodes 4. TRANSFORMER-COUPLED AMPLIFIERS (i) With resistive load (ii) Effect of primary resistance (iii) With i-f voltage amplifiers (iv) R-F amplifiers with sliding screen
13 15 15 17 18 21 22 23 23 24 24 24 26 27 27 28 28 28
(x)
CONTENTS SECTION
5.
6.
7.
8.
9.
10.
(v) Cathode loadlines (vi) With reactive loads TRIODE OPERATION OF PENTODES (i) Triode operation of pentodes (ii) Examples of transconductance calculation (iii) Triode amplification factor (iv) Plate resistance (v) Connection of suppressor grid CONVERSION FACTORS, AND THE CALCULATION OF CHARACTERISTICS OTHER THAN THOSE PUBLISHED (i) The basis of valve conversion factors (ii) The use of valve conversion factors (iii) The calculation of valve characteristics other than those published (iv) The effect of changes in operating conditions VALVE EQUIVALENT CIRCUITS AND VECTORS (i) Constant voltage equivalent circuit (ii) Constant current equivalent circuit (iii) Valve vectors VALVE ADMITTANCES (i) Grid input impedance and admittance (ii) Admittance coefficients (iii) The components of grid admittance-input resistanceinput capacitance-grid input admittance (iv) Typical values of short-circuit input conductance (v) Change of short-circuit-input capacitance with transconductance (vi) Grid-cathode capacitance (vii) Input capacitances of pentodes (published values) (viii) Grid-plate capacitance MATHEMATICAL RELATIONSHIPS (i) General (ii) Resistance load (iii) Power and efficiency (iv) Series expansion; resistance load (v) Series expansion; general case (vi) The equivalent plate circuit theorem (vii) Dynamic load line-general case(viii) Valve networks-general case(ix) Valve coefficients as partial differentials (x) Valve characteristics at low plate currents REFERENCES
CHAPTER 3. THE TESTING OF OXIDE-COATED CATHODE HIGH-VACUUM RECEIVING VALVES 1. BASIS OF TESTING PRACTICE (i) Fundamental physical properties (ii) Basic functional characteristics (iii) Fundamental characteristic tests (iv) Valve ratings and their limiting effect on operation (A) Limiting ratings (B) Characteristics usually rated (C) Rating systems (D) Interpretation of maximum ratings (E) Operating conditions (v) Recommended practice and operation (a) Mounting (b) Ventilation (xi)
PAGE
29 30 34 34 34 35 36 36 36 36 37 40 42 45 45 46 47 49 49 50 51 55 55 56 56 57 57 57 58 59 61 63 63 64 64 64 65 66
68 69 70 73 75 75 75 77 77 80 80 80 81
CONTENTS SECTION
PAGE
(c) (d) (e) (f) (g) (h)
Heater-cathode insulation Control grid circuit resistance Operation at low screen voltages Microphony Hum Stand-by operation
81 82 84 84 84 84
2. CONTROL OF CHARACTERISTICS DURING MANUFACTURE (i) Importance of control over characteristics (ii) Basic manufacturing test specification (iii) Systematic testing (iv) Tolerances on characteristics 3. METHODS OF TESTING CHARACTERISTICS (i) General conventions (ii) General characteristics (a) Physical dimensions (b) Shorts and continuity (c) Heater (or filament) current (d) Heater to cathode leakage (e) Inter-electrode insulation (f) Emission (g) Direct inter-electrode capacitances (iii) Specific diode characteristics (a) Rectification test (b) Sputter and arcing (c) Back emission (d) Zero signal or standing diode current (iv) Specific triode, pentode and beam tetrode characteristics (A) Reverse grid current (B) Grid current commencement voltage (C) Positive grid current (D) Positive voltage electrode currents (E) Transconductance or mutual conductance (F) Amplification factor (G) Plate resistance (H) A.C. amplification (I) Power output (J) Distortion (K) Microphony (L) Audio frequency noise (M) Radio frequency noise (N) Blocking (O) Stage gain testing (P) Electrode dissipation (v) Specific converter characteristics (A) Methods of operation including oscillator excitation (1) Oscillator self-excited (2) Oscillator driven (3) Static operation (B) Specific characteristics (a) Reverse signal grid current (b) Signal-grid current commencement (c) Mixer positive voltage electrode currents (d) Mixer conversion transconductance (e) Mixer plate resistance (f) Mixer transconductance (g) Oscillator grid current (xii)
85 85 85 86 88 89 90 91 91 91 93 94 94 94 95 99 99 100 100 101 101 101 102 102 103 103 104 104 105 105 106 107 107 107 107 108 108 108 108 108 109 109 109 109 109 109 109 111 111 111
CONTENTS SECTION
PAGE
(h) Oscillator plate current (i) Oscillator transconductance (j) Oscillator amplification factor (k) Oscillator plate resistance (1) Signal-grid blocking (m) Microphony (n) R-F noise (vi) Tests for special characteristics (A) Short-circuit input admittance (B) Short-circuit feedback admittance (C) Short-circuit output admittance (D) Short-circuit forward admittance (E) Perveance (vii) Characteristics by pulse methods-point by point (viii) Characteristics by curve tracer methods
113 113 113 113 113 113 113 113 113 117 117 117 117 118 119
4. ACCEPTANCE TESTING (i) Relevant characteristics (ii) Valve specifications (iii) Testing procedure
120 120 120 120
5. SERVICE TESTING AND SERVICE TESTER PRACTICE (i) Purpose and scope of service testing and discussion of associated problems (ii) Fundamental characteristics which should be tested (iii) Types of commercial testers (iv) Methods of testing characteristics in commercial service testers (a) Shorts testing (b) Continuity testing (c) Heater to cathode leakage (d) Emission testing (e) Mutual conductance testing (f) Plate conductance testing (g) Reverse grid current testing (h) Power output testing (i) Conversion conductance testing (j) Oscillator mutual conductance testing (k) Noise testing (1) A.C. amplification testing (v) A.C. versus d.c. electrode voltages in testers (vi) Pre-heating (vii) Testing procedure
121 121 122 122 123 123 123 123 123 123 124 124 124 124 124 124 124 124 125 125
6. REFERENCES
125 PART 2: GENERAL THEORY AND COMPONENTS CHAPTER 4. THEORY OF NETWORKS
1. CURRENT AND VOLTAGE (i) Direct current (ii) Alternating current (iii) Indications of polarity and current flow 2. RESISTANCE (i) Ohm's Law for d.c. (ii) Ohm's Law for a.c. (iii) Resistances in series (iv) Resistances in parallel (v) Conductance in resistive circuits
128 128 129 130 130 130 131 131 132 133 (xiii)
CONTENTS SECTION
PAGE
3. POWER (i) Power in d.c. circuits (ii) Power in resistive a.c. circuits
133 133 133
4. CAPACITANCE (i) Introduction to capacitance (ii) Condensers in parallel and series (iii) Calculation of capacitance (iv) Condensers in d.c. circuits (v) Condensers in a.c. circuits
134 134 135 135 136 137
5. INDUCTANCE (i) Introduction to inductance (ii) Inductances in d.c. circuits (iii) Inductances in series and parallel (iv) Mutual inductance (v) Inductances in a.c. circuits (vi) Power in inductive circuits
140 140 141 141 142 142 143
6. IMPEDANCE AND ADMITTANCE (i) Impedance, a complex quantity (ii) Series circuits with L, C and R (iii) Parallel combinations of L, C and R (iv) Series-parallel combinations of L, C and R (v) Conductance, susceptance and admittance (vi) Conversion from series to parallel impedance
144 144 144 147 149 153 157
7. NETWORKS (i) Introduction to networks (ii) Kirchhoff's Laws (iii) Potential dividers (iv) Thevenin's Theorem (v) Norton's Theorem (vi) Maximum Power Transfer Theorem (vii) Reciprocity Theorem (viii) Superposition Theorem (ix) Compensation Theorem (x) Four-terminal networks (xi) Multi-mesh networks (xii) Non-linear components in networks (xiii) Phase shift networks (xiv) Transients in networks (xv) References to networks
158 158 160 161 164 165 165 165 165 166 166 167 170 170 171 171
8. FILTERS (i) Introduction to filters (ii) Resistance-capacitance filters, high-pass and low-pass (iii) Special types of resistance-capacitance filters (iv) Iterative impedances of four terminal networks (v) Image impedances and image transfer constant of four terminal networks (vi) Symmetrical networks (vii) "Constant k " filters (viii) M-derived filters (ix) Practical filters (x) Frequency dividing networks (xi) References to filters
172 172 172 176 176
(xiv)
177 179 179 182 184 184 185
CONTENTS SECTION
PAGE
9. PRACTICAL RESISTORS, CONDENSERS AND INDUCTORS (i) Practical resistors (ii) Practical condensers (iii) Combination units (iv) Practical inductors (v) References to practical resistors and condensers
186 186 191 197 197 198
CHAPTER 5. TRANSFORMERS AND IRON-CORED INDUCTORS 1. IDEAL TRANSFORMERS (i) Definitions (ii) Impedance calculations-single load(iii) Impedance calculations-multiple loads-
199 199 200 201
2. PRACTICAL TRANSFORMERS (i) General considerations (ii) Effects of losses
204 204 205
3. AUDIO-FREQUENCY TRANSFORMERS (i) General considerations (ii) Core materials (iii) Frequency response and distortion (a) Interstage transformers (b) Low level transformers (c) Output transformers (iv) Designing for low leakage inductance (v) Winding capacitance (vi) Tests on output transformers (vii) Specifications for a-f transformers
206 206 207
4. MAGNETIC CIRCUIT THEORY (i) Fundamental magnetic relationships (ii) The magnetic circuit (iii) Magnetic units and conversion factors
229 229 231 232
5. POWER TRANSFORMERS (i) General (ii) Core material and size (iii) Primary and secondary turns (iv) Currents in windings (v) Temperature rise (vi) Typical design (vii) Specifications for power transformers
233 233 234 235 236 236 237 241
6. IRON-CORED INDUCTORS (i) General (ii) Calculations-general(iii) Effective permeability (iv) Design with no d.c. flux (v) Design of high Q inductors (vi) Design with d.c. flux (vii) Design by Hanna's method (viii) Design of inductors for choke-input filters (ix) Measurements (x) Iron-cored inductors in resonant circuits
242 242 242 243 243 245 247 248 249 250 251
7. REFERENCES
252
209 210 211 217 219 227 228
(xv)
CONTENTS SECTION
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CHAPTER 6. MATHEMATICS 1. ARITHMETIC AND THE SLIDE RULE (i) Figures (ii) Powers and roots (iii) Logarithms (iv) The slide rule (v) Short cuts in arithmetic
255 255 255 255 257 258
2. ALGEBRA (i) Addition (ii) Subtraction (iii) Multiplication (iv) Division (v) Powers (vi) Roots (vii) Brackets and simple manipulations (viii) Factoring (ix) Proportion (x) Variation (xi) Inequalities (xii) Functions (xiii) Equations (xiv) Formulae and laws (xv) Continuity and limits (xvi) Progressions, sequences and series (xvii) Logarithmic and exponential functions (xviii) Infinite series (xix) Hyperbolic functions (xx) General approximations
259 260 260 260 260 260 261 261 262 262 262 262 263 263 265 265 266 267 268 269 271
3. GEOMETRY AND TRIGONOMETRY (i) Plane figures (ii) Surfaces and volumes of solids (iii) Trigonometrical relationships
272 272 275 275
4. PERIODIC PHENOMENA
278
5. GRAPHICAL REPRESENTATION AND j NOTATION (i) Graphs (ii) Finding the equation to a curve (iii) Three variables (iv) Vectors and j notation
279 279 281 281 282
6. COMPLEX ALGEBRA AND DE MOIVRE'S THEOREM (i) Complex algebra with regular coordinates (ii) Complex algebra with polar coordinates (iii) De Moivre's Theorem
285 285 286 287
7. DIFFERENTIAL AND INTEGRAL CALCULUS (i) Slope and rate of change (ii) Differentiation (iii) Integration (iv) Taylor's Series (v) Maclaurin's Series
289 289 291 294 298 299
8. FOURIER SERIES AND HARMONICS (i) Periodic waves and the Fourier Series (ii) Other applications of the Fourier Series (iii) Graphical Harmonic Analysis
299 299 302 302
9. REFERENCES
304 (xvi)
CONTENTS SECTION
PAGE
CHAPTER 7. NEGATIVE FEEDBACK 1. FUNDAMENTAL TYPES OF FEEDBACK (i) Feedback positive and negative (ii) Negative voltage feedback at the mid-frequency (iii) Negative current feedback at the mid-frequency (iv) Bridge negative feedback at the mid-frequency (v) Combined positive and negative at the mid-frequency (vi) Comparison between different fundamental types at the midfrequency 2. PRACTICAL FEEDBACK CIRCUITS (i) The cathode follower (ii) The cathode degenerative amplifier and phase splitter (iii) Voltage feedback from secondary of output transformer (iv) Voltage feedback from plate-transformer input(v) Voltage feedback from plate-r.c.c. input(vi) Voltage feedback over two stages (vii) Voltage feedback over three stages (viii) Cathode coupled phase inverters and amplifiers (ix) Hum (x) Some special features of feedback amplifiers (xi) Combined positive and negative feedback (xii) Choke-coupled phase inverter 3. STABILITY, PHASE SHIFT AND FREQUENCY RESPONSE (i) Stability and instability (ii) Conditions for stability (iii) Relationship between phase shift and attenuation (iv) Design of 1 and 2 stage amplifiers (v) Design of multistage amplifiers (vi) Effect of feedback on frequency response (vii) Design of amplifiers with flat frequency response (viii) Constancy of characteristics with feedback (ix) Effect of feedback on phase shift 4. SPECIAL APPLICATIONS OF FEEDBACK 5. VALVE CHARACTERISTICS AND FEEDBACK (i) Triode cathode follower (ii) Pentode cathode follower (iii) Triode with voltage feedback (iv) Pentode with voltage feedback, transformer coupled (v) Cathode degenerative triode (vi) Cathode degenerative pentode (vii) Cathode-coupled triodes (viii) Feedback over two stages 6. REFERENCES TO FEEDBACK 7. OVERLOADING OF FEEDBACK AMPLIFIERS ON TRANSIENTS CHAPTER 8. WAVE MOTION AND THE THEORY OF MODULATION 1. INTRODUCTION TO ELECTROMAGNETIC WAVES (i) Wave motion (ii) Electromagnetic spectrum (iii) Wave propagation 2. TRANSMISSION OF INTELLIGENCE (i) Introduction (ii) Radio telegraphy (iii) Radio telephony 3. REFERENCES (xvii)
306 306 307 312 313 314 315 316 316 327 330 332 332 334 344 347 348 352 352 355 356 356 356 359 364 365 378 379 388 389 389 390 390 393 394 395 397 399 399 399 399 1477
403 403 404 404 405 405 405 405 406
CONTENTS SECTION
PAGE
CHAPTER 9. TUNED CIRCUITS 1. 2. 3. 4. 5. 6.
7.
8.
9. 10. 11. 12.
INTRODUCTION DAMPED OSCILLATIONS SERIES RESONANCE PARALLEL RESONANCE GENERAL CASE OF SERIES RESONANCE SELECTIVITY AND GAIN (i) Single tuned circuit (ii) Coupled circuits-tuned secondary(iii) Coupled circuits-tuned primary, tuned secondary(iv) Coupled circuits of equal Q (v) Coupled circuits of unequal Q SELECTIVITY-GRAPHICAL METHODS(i) Single tuned circuit (ii) Two identical coupled tuned circuits COUPLING OF CIRCUITS (i) Mutual inductive coupling (ii) Miscellaneous methods of coupling (iii) Complex coupling RESPONSE OF IDENTICAL AMPLIFIER STAGES IN CASCADE UNIVERSAL SELECTIVITY CURVES SUMMARY OF FORMULAE FOR TUNED CIRCUITS REFERENCES
CHAPTER 10. CALCULATION OF INDUCTANCE 1. SINGLE LAYER COILS OR SOLENOIDS (i) Current-sheet inductance (ii) Solenoids wound with spaced round wires (iii) Approximate formulae (iv) Design of single layer solenoid (v) Magnitude of the differences between Ls and Lo (vi) Curves for the determination of the " current-sheet" inductance (vii) Effect of concentric, non-magnetic screen 2. MULTILAYER SOLENOIDS (i) Formula for current sheet inductance (ii) Correction for insulation thickness (iii) Approximate formulae (iv) Design of multilayer coils (v) Effect of a concentric screen 3. TOROIDAL COILS (i) Toroidal coil of circular section with single layer winding (ii) Toroidal coil of rectangular section with single layer winding (iii) Toroidal coil of rectangular section with multilayer winding 4. FLAT SPIRALS (i) Accurate formulae (ii) Approximate formulae 5. MUTUAL INDUCTANCE (i) Accurate methods (ii) Approximate methods 6. LIST OF SYMBOLS 7. REFERENCES (xviii)
407 408 409 410 412 412 412 413 414 415 416 416 416 417 418 418 418 420 421 421 423 427
429 429 430 432 433 435 437 438 441 441 442 442 443 444 445 445 445 445 445 445 446 446 446 448 448 448
CONTENTS SECTION
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CHAPTER 11. DESIGN OF RADIO FREQUENCY INDUCTORS 1. INTRODUCTION
450
2. SELF-CAPACITANCE OF COILS (i) Effects of self-capacitance (ii) Calculation of self-capacitance of single-layer solenoids (iii) Measurement of self-capacitance
451 451 451 453
3. INTERMEDIATE-FREQUENCY WINDINGS (i) Air-cored coils (ii) Iron-cored coils (iii) Expanding selectivity i-f transformers (iv) Calculation of gear ratios for universal coils (v) Miscellaneous considerations
453 453 454 455 456 458
4. MEDIUM WAVE-BAND COILS (i) Air-cored coils (ii) Iron-cored coils (iii) Permeability tuning (iv) Matching
459 459 460 461 462
5. SHORT-WAVE COILS (i) Design (ii) Miscellaneous features
463 463 468
6. RADIO-FREQUENCY CHOKES (i) Pie-wound chokes (ii) Other types 7. TROPIC PROOFING (i) General considerations (ii) Baking (iii) Impregnation (iv) Flash dipping (v) Materials
474 474 475 476 476 476 477 477 477
8. REFERENCES
478
PART 3: AUDIO FREQUENCIES CHAPTER 12. AUDIO FREQUENCY VOLTAGE AMPLIFIERS 1. INTRODUCTION (i) Voltage amplifiers
481 481
2. RESISTANCE-CAPACITANCE COUPLED TRIODES (i) Choice of operating conditions (ii) Coupling condenser (iii) Cathode bias (iv) Fixed bias (v) Grid leak bias (vi) Plate voltage and current (vii) Gain and distortion at the mid-frequency (viii) Dynamic characteristics (ix) Maximum voltage output and distortion (x) Conversion factors with r.c.c. triodes (xi) Input impedance and Miller effect (xii) Equivalent circuit of r.c.c. triode (xiii) Voltage gain and phase shift (xiv) Comments on tabulated characteristics of resistancecoupled triodes
482 482 483 484 487 489 489 490 491 491 493 493 494 494 495 (xix)
CONTENTS SECTION
PAGE
3. RESISTANCE-CAPACITANCE COUPLED PENTODES (i) Choice of operating conditions (ii) Coupling condenser (iii) Screen by-pass (iv) Cathode bias (v) Fixed bias (vi) Dynamic characteristics of pentodes (vii) Gain at the mid-frequency (viii) Dynamic characteristics of pentodes and comparison with triodes (ix) Maximum voltage output and distortion (x) Conversion factors with r.c.c. pentodes (xi) Equivalent circuit of r.c.c. pentode (xii) Voltage gain and phase shift (xiii) Screen loadlines (xiv) Combined screen and cathode loadlines and the effect of tolerances (xv) Remote cut-off pentodes as r.c.c. amplifiers (xvi) Multigrid valves as r.c.c. amplifiers (xvii) Special applications (xviii) Comments on tabulated characteristics of resistancecoupled pentodes 4. TRANSFORMER-COUPLED VOLTAGE AMPLIFIERS (i) Introduction (ii) Gain at the mid-frequency (iii) Gain at low frequencies (iv) Desirable valve characteristics (v) Equivalent circuits (vi) Gain and phase shift at all frequencies (vii) Transformer characteristics (viii) Fidelity (ix) Valve loadlines (x) Maximum peak output voltage (xi) Transformer loading (xii) Parallel feed (xiii) Auto-transformer coupling (xiv) Applications (xv) Special applications 5. CHOKE-COUPLED AMPLIFIERS (i) Performance (ii) Application 6. METHODS OF EXCITING PUSH-PULL AMPLIFIERS (i) Methods involving iron-cored inductors (ii) Phase splitter (iii) Phase inverter (iv) Self-balancing phase inverter (v) Self-balancing paraphase inverter (vi) Common cathode impedance self-balancing inverters (vii) Balanced output amplifiers with highly accurate balance (viii) Cross coupled phase inverter 7. PUSH-PULL VOLTAGE AMPLIFIERS (i) Introduction (ii) Cathode resistors (iii) Output circuit (iv) Push-pull impedance-coupled amplifiers—mathematical treatment (v) Phase compressor (xx)
496 496 496 496 499 501 504 506 508 510 511 512 512 513 515 516 516 516 517 517 517 517 517 517 518 518 518 518 518 518 518 518 520 520 520 521 521 521 521 521 522 524 524 524 526 527 527 527 527 527 527 528 528
CONTENTS SECTION
PAGE
8. IN-PHASE AMPLIFIERS (i) Cathode-coupled amplifiers (ii) Grounded-grid amplifiers (iii) Inverted input amplifiers (iv) Other forms of in-phase amplifiers
529 529 529 529 529
9. DIRECT-COUPLED AMPLIFIERS (i) Elementary d-c amplifiers (ii) Bridge circuit (iii) Cathode-coupled (iv) Cathode follower (v) Phase inverter (vi) Screen coupled (vii) Gas tube coupled (viii) Modulation systems (ix) Compensated d.c. amplifiers (x) Bridge-balanced direct current amplifiers (xi) Cascode amplifiers
529 529 530 531 531 532 532 532 532 533 533 533
10. STABILITY, DECOUPLING AND HUM (i) Effect of common impedance in power supply (ii) Plate supply by-passing (iii) Plate circuit decoupling (iv) Screen circuit decoupling (v) Grid circuit decoupling (vi) Hum in voltage amplifiers
535 535 535 535 537 538 538
11. TRANSIENTS AND PULSES IN AUDIO FREQUENCY AMPLIFIERS (i) Transient distortion (ii) Rectangular pulses
540 540 540
12. MULTISTAGE VOLTAGE AMPLIFIERS (i) Single-channel amplifiers (ii) Multi-channel amplifiers
541 541 541
13. REFERENCES
542
CHAPTER 13. AUDIO FREQUENCY POWER AMPLIFIERS 1. INTRODUCTION (i) Types of a-f power amplifiers (ii) Class of operation (iii) Some characteristics of power amplifiers (iv) Effect of power supply on power amplifiers
544 544 545 545 547
2. CLASS A SINGLE TRIODES (i) Simplified graphical conditions, power output and distortion (ii) General graphical case, power output and distortion (iii) Optimum operating conditions (iv) Loudspeaker load (v) Plate circuit efficiency and power dissipation (vi) Power sensitivity (vii) Choke-coupled amplifier (viii) Effect of a.c. filament supply (ix) Overloading (x) Regulation and by-passing of power supply
548 548 550 555 558 559 559 559 560 560 560
(xxi)
CONTENTS SECTION
3. CLASS A MULTI-GRID VALVES (i) Introduction (ii) Ideal pentodes (iii) Practical pentodes-operating conditions(iv) Graphical analysis-power output and distortion(v) Rectification effects (vi) Cathode bias (vii) Resistance and inductance of transformer primary (viii) Loudspeaker load (ix) Effects of plate and screen regulation (x) Beam power valves (xi) Space charge tetrodes (xii) Partial triode (" ultra-linear") operation of pentodes 4. PARALLEL CLASS A AMPLIFIERS 5. PUSH-PULL TRIODES CLASS A, AB1 (i) Introduction (ii) Theory of push-pull amplification (iii) Power output and distortion (iv) Average plate current (v) Matching and the effects of mismatching (vi) Cathode bias (vii) Parasitics 6 PUSH-PULL PENTODES AND BEAM POWER AMPLIFIERS, CLASS A, AB1 (i) Introduction (ii) Power output and distortion (iii) The effect of power supply regulation (iv) Matching and the effects of mismatching (v) Average plate and screen currents (vi) Cathode bias (vii) Parasitics (viii) Phase inversion in the power stage (ix) Extended Class A (x) Partial triode (" ultra-linear ") operation 7. CLASS B AMPLIFIERS AND DRIVERS (i) Introduction (ii) Power output and distortion—ideal conditions—Class B2 (iii) Power output and distortion—practical conditions—Class B2 (iv) Grid driving conditions (v) Design procedure for Class B2 amplifiers (vi) Earthed-grid cathode coupled amplifiers (vii) Class B1 amplifiers—quiescent push-pull 8. CLASS AB2 AMPLIFIERS (i) Introduction (ii) Bias and screen stabilized Class AB2 amplifier (iii) McIntosh amplifier 9. CATHODE-FOLLOWER POWER AMPLIFIERS 10. SPECIAL FEATURES (i) Grid circuit resistance (ii) Grid bias sources (iii) Miller Effect (iv) 26 volt operation (v) Hum from plate and screen supplies 11. COMPLETE AMPLIFIERS (i) Introduction (ii) Design procedure and examples (iii) Loudspeaker load 12. REFERENCES (xxii)
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560 560 561 561 563 565 565 566 566 568 569 569 570 570 571 571 573 577 579 580 582 582 583 583 583 584 584 584 585 585 585 587 587 587 587 588 588 590 592 592 592 593 593 593 594 596 596 596 597 598 598 599 599 599 599 600 601
CONTENTS SECTION
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CHAPTER 14. FIDELITY AND DISTORTION 1. INTRODUCTION (i) Fidelity (ii) Types of distortion (iii) Imagery for describing reproduced sound
603 603 604 604
2. NON-LINEAR DISTORTION AND HARMONICS (i) Non-linearity (ii) Harmonics (iii) Permissible harmonic distortion (iv) Total harmonic distortion (v) Weighted distortion factor (vi) The search for a true criterion of non-linearity
605 605 606 607 609 610 610
3. INTERMODULATION DISTORTION (i) Introduction (ii) Modulation method of measurement—r.m.s. sum (iii) Difference frequency intermodulation method (iv) Individual side-band method (v) Modulation method of measurement—peak sum (vi) Le Bel's oscillographic method (vii) Comparison between different methods (viii) Synthetic bass
611 611 612 613 613 614 614 616 616
4. FREQUENCY DISTORTION (i) Frequency range (ii) Tonal balance (iii) Minimum audible change in frequency range (iv) Sharp peaks
617 617 617 617 618
5. PHASE DISTORTION
618
6. TRANSIENT DISTORTION (i) General survey (ii) Testing for transient response
619 619 619
7. DYNAMIC RANGE AND ITS LIMITATIONS (i) Volume range and hearing (ii) Effect of volume level on frequency range (iii) Acoustical power and preferred listening levels (iv) Volume range in musical reproduction (v) The effect of noise
620 620 621 623 623 624
8. SCALE DISTORTION
625
9. OTHER FORMS OF DISTORTION (i) Frequency-modulation distortion (ii) Variation of frequency response with output level (iii) Listener fatigue
626 626 626 626
10. FREQUENCY RANGE PREFERENCES (i) Tests by Chinn and Eisenberg (ii) Tests by Olson (iii) Single channel versus dual-channel tests (iv) Summing up
627 627 627 627 628
11. SPEECH REPRODUCTION (i) The characteristics of speech (ii) Articulation (iii) Masking of speech by noise (iv) Distortion in speech reproduction (v) Frequency ranges for speech
628 628 628 629 629 630 (xxiii)
CONTENTS SECTION
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12. HIGH FIDELITY REPRODUCTION (i) The target of high fidelity (ii) Practicable high fidelity (iii) The ear as a judge of fidelity 13. REFERENCES
630 630 630 632 632
CHAPTER 15. TONE COMPENSATION AND TONE CONTROL 1. INTRODUCTION (i) The purpose of tone compensation (ii) Tone control (iii) General considerations (iv) Distortion due to tone control (v) Calculations involving decibels per octave (vi) Attenuation expressed as a time constant (vii) The elements of tone control filters (viii) Fundamental circuit incorporating R and C (ix) Damping of tuned circuits (x) Tolerances of elements 2. BASS BOOSTING (i) General remarks (ii) Circuits not involving resonance or negative feedback (iii) Methods incorporating resonant circuits (iv) Circuits involving feedback (v) Regeneration due to negative resistance characteristic 3. BASS ATTENUATION (i) General remarks (ii) Bass attenuation by grid coupling condensers (iii) Bass attenuation by cathode resistor by-passing (iv) Bass attenuation by screen by-passing (v) Bass attenuation by reactance shunting (vi) Bass attenuation by negative feedback (vii) Bass attenuation by Parallel-T network (viii) Bass attenuation using Constant k filters (ix) Bass attenuation using M-derived filters 4. COMBINED BASS TONE CONTROLS (i) Stepped controls (ii) Continuously variable controls 5. TREBLE BOOSTING (i) General remarks (ii) Circuits not involving resonance or negative feedback (iii) Methods incorporating resonant circuits (iv) Circuits involving feedback 6. TREBLE ATTENUATION (i) General remarks (ii) Attenuation by shunt capacitance (iii) Treble attenuation by filter networks (iv) Treble attenuation in negative feedback amplifiers 7. COMBINED TREBLE TONE CONTROLS 8. COMBINED BASS AND TREBLE TONE CONTROLS (i) Stepped controls-general— (ii) Quality switch (iii) Universal step-type tone control not using inductors (iv) Universal step-type tone control using inductors (v) Fixed bass and treble boosting
635 635 636 636 636 637 638 639 639 639 639 640 640 640 644 645 648 649 649 649 649 650 650 651 651 652 652 653 653 653 653 653 653 654 655 655 655 655 657 657 658 658 658 659 660 661 662
(xxiv)
CONTENTS SECTION
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(vi) Step-type tone control using negative feedback (vii) Continuously-variable controls—general (viii) Single control continuously-variable tone controls (ix) Ganged continuously-variable tone controls (x) Dual control continuously-variable tone controls FEEDBACK TO PROVIDE TONE CONTROL (i) Introduction (ii) Amplifiers with feedback providing tone control (iii) Whistle filters using feedback AUTOMATIC FREQUENCY-COMPENSATED VOLUME CONTROL (i) Introduction (ii) Methods incorporating a tapped potentiometer (iii) Methods incorporating step-type controls (iv) Method incorporating inverse volume expansion with multi-channel amplifier WHISTLE FILTERS (i) Resonant circuit filters (ii) Narrow band rejection filter (iii) Crystal filters (iv) Parallel-T network (v) Filters incorporating L and C OTHER METHODS OF TONE CONTROL (i) Multiple-channel amplifiers (ii) Synthetic bass THE LISTENER AND TONE CONTROL EQUALIZER NETWORKS REFERENCES
662 662 662 664 664 669 669 669 672 672 672 672 673 673 673 673 675 675 675 676 676 676 676 677 677 677
CHAPTER 16. VOLUME EXPANSION, COMPRESSION AND LIMITING 1. GENERAL PRINCIPLES (i) Introduction (ii) An ideal system (iii) Practical problems in volume expansion (iv) Distortion (v) General comments 2. VOLUME COMPRESSION (i) Introduction (ii) Peak limiters (iii) Volume limiters (iv) Distortion caused by peak limiters or volume limiters (v) Volume compression (vi) Volume compression plus limiting (vii) Compression of commercial speech 3. GAIN CONTROL DEVICES (i) Remote cut-off pentodes (ii) Pentagrids and triode-hexodes (iii) Plate resistance control (iv) Negative feedback (v) Lamps (vi) Suppressor-grid control
679 679 680 680 681 681 681 681 682 683 683 683 684 684 684 684 685 685 685 685 686 (xxv)
CONTENTS SECTION
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4. VOLUME EXPANSION (i) Introduction (ii) Expanders incorporating lamps (iii) Expanders utilizing feedback (iv) Expanders incorporating remote cut-off pentodes (v) Expanders incorporating remote cut-off triodes (vi) Expanders incorporating suppressor-grid controlled pentodes (vii) Expanders incorporating valves with five grids (viii) Expanders incorporating plate resistance control 5. PUBLIC ADDRESS A.V.C. 6. SPEECH CLIPPERS 7. NOISE PEAK AND OUTPUT LIMITERS (i) Introduction (ii) Instantaneous noise peak limiters (iii) Output limiters (iv) General remarks 8. REFERENCES
686 686 687 688 688 689 689 691 692 693 693 694 694 694 698 699 699
CHAPTER 17. REPRODUCTION FROM RECORDS 1. INTRODUCTION TO DISC RECORDING (i) Methods used in sound recording (ii) Principles of lateral recording (iii) Frequency range (iv) Surface noise and dynamic range (v) Processing (vi) Turntables and driving mechanism (vii) Automatic record changers 2. DISCS AND STYLI (i) General information on discs (ii) Dimensions of records and grooves (iii) Styli (iv) Pinch effect (v) Radius compensation (vi) Record and stylus wear 3. PICKUPS (i) General survey (ii) Electro-magnetic (moving iron) pickups (iii) Dynamic (moving coil) pickups (iv) Piezo-electric (crystal) pickups (v) Magnetostriction pickups (vi) Strain-sensitive pickups (vii) Ribbon pickups (viii) Capacitance pickups (ix) Eddy-current pickups 4. TRACKING (i) General survey of the problem (ii) How to design for minimum distortion (iii) The influence of stylus friction 5. RECORDING CHARACTERISTICS, EQUALIZERS AND AMPLIFIERS (i) Recording characteristics (ii) Pre-amplifiers for use with pickups (iii) Introduction to equalizers (iv) High-frequency attenuation (scratch filter) (v) Equalizers for electro-magnetic pickups
701 701 702 704 704 705 705 705 706 706 706 709 711 711 712 714 714 717 719 720 721 721 722 722 723 723 723 725 726 727 727 732 732 737 738
(xxvi)
CONTENTS SECTION
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(vi) Equalizers for crystal pickups (vii) Equalizers applying negative feedback to the pickup (viii) Miscellaneous details regarding equalizing amplifiers (ix) Complete amplifiers (x) Pickups for connection to radio receivers (xi) Frequency test records DISTORTION AND UNDESIRABLE EFFECTS (i) Tracing distortion and pinch effect (ii) Playback loss (iii) Wow, and the effects of record warping (iv) Distortion due to stylus wear (v) Noise modulation (vi) Pickup distortion (vii) Acoustical radiation (viii) Distortion in recording NOISE REDUCTION (i) Analysis of noise (ii) High-frequency attenuation (iii) High-frequency pre-emphasis and de-emphasis (iv) Volume expansion (v) Olson noise suppressor (vi) Scott dynamic noise suppressor (vii) Price balanced clipper noise suppressor LACQUER DISC HOME RECORDING (DIRECT PLAYBACK) (i) General description (ii) Recording characteristic (iii) Cutting stylus (iv) Cutter head (v) Equalization of cutter (vi) Motor and turntable (vii) Amplifier (viii) Pickups for use on lacquer discs (ix) Recording with embossed groove REPRODUCTION FROM TRANSCRIPTION DISCS (i) Introduction (ii) Characteristics of record material, wear and noise (iii) Sound track (iv) Recording characteristics and equalization (v) Translation loss and radius compensation REFERENCES TO LATERAL DISC RECORDING
741 743 743 744 751 752 757 757 760 760 761 761 762 762 762 763 763 763 763 763 763 764 765 766 766 766 767 767 767 767 767 768 768 769 769 769 770 770 770 771
CHAPTER 18. MICROPHONES, PRE-AMPLIFIERS, ATTENUATORS AND MIXERS 1. MICROPHONES (i) General survey (ii) Carbon microphones (iii) Condenser microphones (iv) Crystal and ceramic microphones (v) Moving coil (dynamic)microphones (vi) Pressure ribbon microphones (vii) Velocity ribbon microphones (viii) Throat microphones (ix) Lapel microphones (x) Lip microphones
775 775 777 778 778 779 779 779 780 780 780 (xxvii)
CONTENTS SECTION
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(xi) The directional characteristics of microphones (xii) The equalization of microphones (xiii) Microphone transformers (xiv) Standards for microphones 2. PRE-AMPLIFIERS (i) Introduction (ii) Noise (iii) Hum (iv) Microphony (v) Valves for use in pre-amplifiers (vi) Microphone pre-amplifiers (vii) Pickup pre-amplifiers (viii) Gain-controlled pre-amplifiers (ix) Standard pre-amplifiers for broadcasting (x) Standard pre-amplifiers for sound equipment 3. ATTENUATORS AND MIXERS (i) Potentiometer type attenuators (volume controls) (ii) Single section attenuators-constant impedance— (iii) Single section attenuators-constant impedance in one direction— only (iv) Multiple section attenuators (v) Electronic attenuators (vi) Mixers and faders—general (vii) Non-constant impedance mixers and faders (viii) Constant impedance mixers and faders 4. REFERENCES
780 781 781 781 782 782 782 784 786 786 788 793 793 793 793 794 794 795 795 796 797 798 798 801 804
CHAPTER 19. UNITS FOR THE MEASUREMENT OF GAIN AND NOISE 1. BELS AND DECIBELS (i) Power relationships expressed in bels and decibels (ii) Voltage and current relationships expressed in decibels (iii) Absolute power and voltage expressed in decibels (iv) Microphone output expressed in decibels (v) Pickup output expressed in decibels (vi) Amplifier gain expressed in decibels (vii) Combined microphone and amplifier gain expressed in decibles (viii) Loudspeaker output expressed in decibels (ix) Sound system rating (x) Tables and charts of decibel relationships (xi) Nomogram for adding decibel-expressed quantities (xii) Decibels, slide rules and mental arithmetic 2. VOLUME INDICATORS AND VOLUME UNITS (i) Volume indicators (ii) Volume units 3. INDICATING INSTRUMENTS (i) Decibel meters (ii) Power output meters (iii) Volume indicators (iv) Acoustical instruments 4. NEPERS AND TRANSMISSION UNITS (i) Nepers (ii) Transmission units (xxviii)
806 806 807 807 808 810 810 811 812 812 813 821 822 823 823 824 825 825 825 825 825 825 825 826
CONTENTS SECTION
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5. LOUDNESS (i) Introduction to loudness (ii) The phon (iii) Loudness units 6. THE MEASUREMENT OF SOUND LEVEL AND NOISE (i) Introduction (ii) The sound level meter (iii) The measurement of noise in amplifiers (iv) The measurement of radio noise 7. REFERENCES
826 826 826 827 827 827 828 829 829 830
CHAPTER 20. LOUDSPEAKERS 1. INTRODUCTION (i) Types of loudspeakers (ii) Direct radiator loudspeakers (iii) Horn loudspeakers (iv) Headphones (v) Loudspeaker characteristics (vi) Amplitude of cone movement (vii) Good qualities of loudspeakers (viii) Loudspeaker grilles 2. CHARACTERISTICS OF MOVING-COIL CONE LOUDSPEAKERS (i) Rigid (piston) cone in an infinite flat baffle (ii) Practical cones (iii) Special constructions for wide frequency range (iv) Impedance and phase angle (v) Frequency response (vi) Efficiency (vii) Directional characteristics (viii) Field magnet (ix) Hum bucking coil (x) Damping 3. BAFFLES AND ENCLOSURES FOR DIRECT-RADIATOR LOUDSPEAKERS (i) Flat baffles (ii) Open back cabinets (iii) Enclosed cabinet loudspeakers (iv) Acoustical phase inverter (" vented baffle ") (v) Acoustical labyrinth loudspeakers (vi) The R-J loudspeaker (vii) Design of exterior of cabinet 4. HORN LOUDSPEAKERS (I) Introduction (ii) Conical horns (iii) Exponential horns (iv) Hyperbolic exponential horns (v) Horn loudspeakers-general— (vi) Folded horn loudspeakers (vii) High-frequency horns (viii) Combination horn and phase inverter loudspeakers for personal radio receivers (ix) Material for making horns 5. DUAL AND TRIPLE SYSTEM LOUDSPEAKERS (i) Introduction (ii) Choice of the cross-over frequency (xxix)
831 831 831 832 832 833 834 834 835 835 835 835 836 837 838 839 839 840 840 840 842 842 842 843 845 850 850 850 851 851 851 851 853 854 856 858 859 859 860 860 860
CONTENTS SECTION
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(iii) The overlap region (iv) Compromise arrangements LOUDSPEAKERS IN OPERATION (i) Loudness (ii) Power required (iii) Acoustics of rooms (iv) Loudspeaker placement (v) Stereophonic reproduction (vi) Sound reinforcing systems (vii) Open air Public Address (viii) Inter-communicating systems (ix) Background music in factories DISTORTION IN LOUDSPEAKERS (i) Non-linearity (ii) Frequency-modulation distortion in loudspeakers (iii) Transient distortion (iv) Sub-harmonics and sub-frequencies (v) Intermodulation distortion SUMMARY OF ACOUSTICAL DATA (i) Definitions in acoustics (ii) Electrical, mechanical and acoustical equivalents (iii) Velocity and wavelength of sound (iv) Musical scales STANDARDS FOR LOUDSPEAKERS (i) Voice coil impedance for radio receivers (ii) Loudspeaker standard ratings for sound equipment REFERENCES TO LOUDSPEAKERS
861 861 861 861 861 864 865 865 866 867 867 867 868 868 869 869 871 871 871 871 872 872 873 874 874 874 876
CHAPTER 21. THE NETWORK BETWEEN THE POWER VALVE AND THE LOUDSPEAKER LOUDSPEAKER "MATCHING" (i) Loudspeaker characteristics and matching (ii) Optimum plate resistance (iii) Procedure for " matching " loudspeakers to various types of amplifiers MULTIPLE AND EXTENSION LOUDSPEAKERS (i) Multiple loudspeakers—general (ii) Sound systems (iii) Extension loudspeakers (iv) Operation of loudspeakers at long distances from amplifier LOUDSPEAKER DIVIDER NETWORKS REFERENCES
880 880 880 881 882 882 883 883 886 887 889
PART 4: RADIO FREQUENCIES CHAPTER 22. AERIALS AND TRANSMISSION LINES 1. INTRODUCTION 2. THE TRANSMISSION LINE (i) Introduction (ii) The correct termination for a transmission line (iii) Impedance-transforming action of a transmission line
890 890 890 890 891 (xxx)
CONTENTS SECTION
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3. AERIALS AND POWER TRANSFER (i) Introduction (ii) Power transfer 4. CHARACTERISTICS OF AERIALS (i) Effective area of a receiving aerial (ii) The power gain of an aerial (iii) The beam-width of an aerial 5. EFFECTS OF THE EARTH ON THE PERFORMANCE OF AN AERIAL (i) Introduction (ii) A perfectly-conducting earth (iii) An imperfectly conducting earth (iv) The attenuation of radio waves in the presence of an imperfectly-reflecting earth 6. THE EFFECT OF THE IONOSPHERE ON THE RECEPTION OF RADIO SIGNALS 7. THE IMPEDANCE OF AN AERIAL (i) Introduction (ii) Resistive component of impedance (iii) Reactive component of impedance (iv) Characteristic impedance of aerial (v) Examples of calculations (vi) Dipoles (vii) Loop aerials 8. DUMMY AERIALS906 9. TYPES OF AERIAL USED FOR BROADCAST RECEPTION (i) Introduction (ii) Medium-frequency receiving aerials (iii) Short-wave receiving aerials (iv) V-H-F aerials 10. REFERENCES
CHAPTER 23. RADIO FREQUENCY AMPLIFIERS 1. INTRODUCTION (i) Aerial coupling (ii) Tuning methods (iii) R-F amplifiers (iv) Design considerations 2. AERIAL STAGES (i) Difficulties involved (ii) Generalized coupling networks (iii) Mutual inductance coupling (iv) Tapped inductance (v) Capacitance coupling (vi) General summary 3. R-F AMPLIFIERS (i) Reasons for using r-f stage (ii) Mutual-inductance-coupled stage (iii) Parallel tuned circuit (iv) Choke-capacitance coupling (v) Untuned and pre-tuned stages (vi) Grounded grid stages 4. IMAGE REJECTION (i) Meaning of image rejection (ii) Image rejection due to aerial stage (iii) Other considerations (xxxi)
892 892 892 893 893 894 894 894 894 894 896 896 901 901 901 902 903 903 903 904 905 907 907 907 908 909 911
912 912 913 913 914 915 915 915 916 920 921 921 922 922 922 923 924 924 925 925 925 926 926
CONTENTS SECTION
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5. EFFECTS OF VALVE INPUT ADMITTANCE (i) Important general considerations (ii) Input loading of receiving valves at radio frequencies (A) Input conductance (B) Cold input conductance (C) Hot input conductance (D) Change in input capacitance (E) Reduction of detuning effect 6. VALVE AND CIRCUIT NOISE (i) Thermal agitation noise (ii) Shot noise (iii) Induced grid noise (iv) Total noise calculations (v) Sample circuit calculations (vi) Conclusions 7. INSTABILITY IN R-F AMPLIFIERS (i) Causes of instability (ii) Inter-electrode capacitance coupling (iii) Summary 8. DISTORTION (i) Modulation envelope distortion (ii) Cross modulation distortion 9. BIBLIOGRAPHY
927 927 928 929 929 930 932 933 935 935 936 939 940 941 942 942 942 943 944 944 945 945 945
CHAPTER 24. OSCILLATORS 1. INTRODUCTION 2. TYPES OF OSCILLATOR CIRCUITS (i) Tuned plate oscillator (ii) Tuned grid oscillator (iii) Hartley oscillator (iv) Colpitts oscillator (v) Electron-coupled oscillator (vi) Negative transconductance oscillators 3. CLASS A1 B AND C OSCILLATORS 4. CAUSES OF OSCILLATOR FREQUENCY VARIATION (i) General (ii) Changes due to supply voltage (iii) Temperature and humidity changes (iv) Oscillator harmonics 5. METHODS OF FREQUENCY STABILIZATION 6. UNSTABLE OSCILLATION 7. PARASITIC OSCILLATION 8. METHODS USED IN PRACTICAL DESIGN 9. BEAT FREQUENCY OSCILLATORS 10. BIBLIOGRAPHY
947 949 949 950 951 952 953 953 954 955 955 955 955 956 957 958 959 959 960 961
CHAPTER 25. FREQUENCY CONVERSION AND TRACKING 1. THE OPERATION OF FREQUENCY CONVERTERS AND MIXERS (i) Introduction (ii) General analysis of operation common to all types (iii) The oscillator section of converter tubes (iv) The detailed operation of the modulator or mixer section of the converter stage (xxxii)
962 962 964 968 968
CONTENTS SECTION
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(v) Conclusion (vi) Appendix 2. CONVERTER APPLICATIONS (i) Broadcast frequencies (ii) Short waves (iii) Types of converters 3. SUPERHETERODYNE TRACKING (i) General (ii) (A) Formulae and charts for superheterodyne oscillator design (B) Worked examples (iii) (A) Padded signal circuits (B) Worked example 4. REFERENCES
984 985 987 987 990 996 1002 1002
CHAPTER 26. INTERMEDIATE FREQUENCY AMPLIFIERS 1. CHOICE OF FREQUENCY (i) Reasons for selection of different frequencies (ii) Commonly accepted intermediate frequencies 2. NUMBER OF STAGES 3. COMMONLY USED CIRCUITS (i) Mutual inductance coupling (ii) Shunt capacitance coupling (iii) Composite i-f transformers 4. DESIGN METHODS (i) General (ii) Critically-coupled transformers (A) Design equations and table (B) Example (C) Design extension (D) Conclusions (E) k measurement (iii) Over-coupled transformers (A) Design equations and table (B) Example (C) k measurement (when k is high) (iv) Under-coupled transformers and single tuned circuits (A) Single tuned circuit equations (B) Example (C) Under-coupled transformer equations (D) Example (v) F-M i-f transformers (vi) I-F transformer construction (vii) Appendix: Calculation of coupling co-efficients 5. VARIABLE SELECTIVITY (i) General considerations (ii) Automatic variable selectivity 6. VARIABLE BANDWIDTH CRYSTAL FILTERS (i) Behaviour of equivalent circuit (ii) Variable bandwidth crystal filters (iii) Design of variable bandwidth i-f crystal filter circuits (A) Simplifying assumptions (B) Gain (C) Gain variation with bandwidth change (D) Selectivity (xxxiii)
1005 1011 1013 1015 1017
1020 1020 1021 1021 1022 1023 1023 1024 1025 1025 1026 1026 1028 1029 1030 1030 1031 1031 1033 1033 1034 1034 1035 1035 1036 1037 1041 1043 1048 1048 1049 1050 1050 1052 1053 1053 1053 1054 1055
CONTENTS SECTION
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(E) Crystal constants (F) Position of filter in circuit (G) Other types of crystal filters (iv) Design example DETUNING DUE TO A.V.C. (i) Causes of detuning (ii) Reduction of detuning effects STABILITY (i) Design data (ii) Neutralizing circuits DISTORTION (i) Amplitude modulation i-f stages (ii) Frequency modulation i-f stages REFERENCES
1056 1057 1057 1057 1061 1061 1062 1065 1065 1065 1067 1067 1068 1069
CHAPTER 27. DETECTION AND AUTOMATIC VOLUME CONTROL 1. A-M DETECTORS (i) Diodes (A) General (B) Diode curves (C) Quantitative design data (D) Miscellaneous data (ii) Other forms of detectors (A) Grid detection (B) Power grid detection (C) Plate detection (D) Reflex detection (E) Regenerative detectors (F) Superregenerative detectors 2. F-M DETECTORS (i) Types of detectors in general use (ii) General principles (iii) Phase discriminators (A) General (B) Design data (C) Design example (iv) Ratio detectors (A) General (B) Operation (C) Types of circuit (D) Design considerations (E) Practical circuits (F) Measurement on ratio detectors 3. AUTOMATIC VOLUME CONTROL (i) Introduction (ii) Simple a.v.c. (iii) Delayed a.v.c. (iv) Methods of feed (v) Typical circuits (vi) A.V.C. application (vii) Amplified a.v.c. (viii) Audio a.v.c. (ix) Modulation rise
1072 1072 1072 1075 1075 1081 1082 1082 1084 1084 1085 1086 1087 1088 1088 1088 1088 1088 1090 1091 1095 1095 1097 1098 1099 1101 1102 1105 1105 1105 1106 1109 1111 1111 1112 1113 1114 (xxxiv)
CONTENTS SECTION
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(x) A.V.C. with battery valves (xi) Special case with simple a.v.c. (xii) The a.v.c. filter and its time constants (xiii) A.V.C. characteristics (xiv) An improved form of a.v.c. characteristic (xv) Design methods MUTING (Q.A.V.C.) (i) General operation (ii) Typical circuits (iii) Circuits used with F-M receivers NOISE LIMITING TUNING INDICATORS (i) Miscellaneous (ii) Electron Ray tuning indicators (iii) Null point indicator using Electron Ray tube (iv) Indicators for F-M receivers CRYSTAL DETECTORS (i) Old type crystal detectors (ii) Fixed germanium crystal detectors (iii) Fixed silicon crystal detectors (iv) Theory of crystal rectification (v) Transistors1138 REFERENCES
1114 1115 1115 1117 1118 1120 1125 1125 1125 1128 1130 1132 1132 1133 1134 1135 1136 1136 1136 1137 1138 1138
CHAPTER 28. REFLEX AMPLIFIERS 1. GENERAL DESCRIPTION (i) Description (ii) Advantages and disadvantages of reflex receivers 2. SOME CHARACTERISTICS OF REFLEX SUPERHET. RECEIVERS (i) Playthrough (residual volume effect) (ii) Over-loading (iii) Automatic volume control (iv) Reduction in percentage modulation (v) Negative feedback (vi) Operating conditions of reflex stage 3. DESIGN OF PLATE REFLEX SUPERHET. RECEIVERS (i) General considerations (ii) Full a.v.c. applied to both stages (iii) Fractional a.v.c. applied to both stages (iv) Full a.v.c. on converter, fractional a.v.c. on reflex stage 4. DESIGN OF SCREEN REFLEX SUPERHET. RECEIVERS (i) Screen reflex receivers (ii) Comparison between plate and screen reflexing 5. DESIGN OF T.R.F. REFLEX RECEIVERS 6. REFERENCES TO REFLEX AMPLIFIERS AND REFLEX RECEIVERS
1140 1140 1140 1142 1142 1142 1142 1143 1143 1143 1143 1143 1143 1143 1144 1145 1145 1146 1146 1146
CHAPTER 29. LIMITERS AND AUTOMATIC FREQUENCY CONTROL 1. LIMITERS (i) General (ii) Typical circuits for F-M receivers 2. AUTOMATIC FREQUENCY CONTROL (i) General principles (ii) Discriminators for a.f.c. (iii) Electronic reactances 3. REFERENCES
1147 1147 1149 1150 1150 1152 1156 1160 (xxxv)
CONTENTS SECTION
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PART 5: RECTIFICATION, REGULATION, FILTERING AND HUM CHAPTER 30. RECTIFICATION INTRODUCTION TO RECTIFICATION (i) Principles of rectification (ii) Rectifier valves and types of service (iii) The use of published curves (iv) Selenium and copper oxide rectifiers RECTIFICATION WITH CONDENSER INPUT FILTER (i) Symbols and definitions (ii) Rectification with condenser input filter (iii) To determine peak and average diode currents (iv) To determine ripple percentage (v) To determine the transformer secondary r.m.s. current (vi) Procedure when complete published data are not available (vii) Approximations when the capacitance is large (viii) Peak hot-switching transient plate current (ix) The effect of ripple RECTIFICATION WITH CHOKE INPUT FILTER (i) Rectification with choke input filter (ii) Initial transient current TRANSFORMER HEATING VOLTAGE MULTIPLYING RECTIFIERS (i) General (ii) Voltage doublers (iii) Voltage triplers (iv) Voltage quadruplers SHUNT DIODE BIAS SUPPLIES
1161 1161 1164 1165 1169 1170 1170 1170 1174 1177 1177 1177 1180 1180 1181 1182 1182 1185 1185 1186 1186 1186 1187 1187 1188
CHAPTER 31. FILTERING AND HUM INDUCTANCE-CAPACITANCE FILTERS RESISTANCE-CAPACITANCE FILTERS PARALLEL-T FILTER NETWORKS HUM—GENERAL (i) Hum due to conditions within the valves (ii) Hum due to circuit design and layout (iii) Hum levels in receivers and amplifiers 5. HUM NEUTRALIZING 6. REFERENCES
1192 1194 1194 1196 1196 1198 1199 1200 1201
CHAPTER 32. VIBRATOR POWER SUPPLIES 1. VIBRATORS—GENERAL PRINCIPLES (i) Operation (ii) Vibrator types (iii) Choice of vibrator (iv) Coil energizing (v) Waveform and time efficiency (vi) Standards for vibrators for auto-radio
1202 1202 1202 1203 1204 1205 1205
1. 2. 3. 4.
(xxxvi)
CONTENTS SECTION
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2. VIBRATOR TRANSFORMER DESIGN (i) General considerations (ii) Transformer calculations (iii) Standards for vibrator power transformers 3. TIMING CAPACITANCE (i) The use of the timing capacitance (ii) Calculation of timing capacitance value (iii) Percentage closure (iv) Effect of flux density on timing capacitance value 4. ELIMINATION OF VIBRATOR INTERFERENCE 5. 12, 24 AND 32 VOLT VIBRATOR SUPPLIES
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CHAPTER 33. CURRENT AND VOLTAGE REGULATORS 1. CURRENT REGULATORS (i) Barretters (ii) Negative temperature coefficient resistors (Thermistors) 2. VOLTAGE REGULATORS (i) Gaseous tube voltage regulators (ii) Valve voltage regulators 3. REFERENCES
1213 1213 1214 1214 1214 1215 1222
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PART 6: COMPLETE RECEIVERS CHAPTER 34. TYPES OF A-M RECEIVERS INTRODUCTION AND SIMPLE RECEIVERS (i) Types of receivers (ii) Crystal sets (iii) Regenerative receivers (iv) Superheterodyne receivers (v) Tuned radio-frequency receivers THE SUPERHETERODYNE THE SYNCHRODYNE REFERENCES
1223 1223 1223 1223 1224 1224 1225 1226 1227
CHAPTER 35. DESIGN OF SUPERHETERODYNE A-M RECEIVERS 1. INTRODUCTION 2. SPECIFICATIONS AND REQUIREMENTS 3. GENERAL DESIGN (i) A.V.C. and noise (ii) Audio-frequency response (iii) Hum (iv) Microphony (v) Instability (vi) The local oscillator (vii) Cabinet design (viii) Ratings (ix) Field testing 4. FREQUENCY RANGES (i) Medium frequency receivers (ii) Dual wave receivers (iii) Multiband receivers (iv) Bandspread receivers
1228 1229 1229 1229 1234 1239 1241 1243 1244 1248 1249 1250 1250 1250 1251 1252 1253 (xxxvii)
CONTENTS SECTION
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5. A.C. OPERATED RECEIVERS (i) Four valve receivers (ii) Five valve receivers (iii) Larger receivers (iv) Communication receivers 6. A.C./D.C. RECEIVERS (i) Series-resistor operation (ii) Barretter operation (iii) Dial lamps (iv) Miscellaneous features 7. BATTERY OPERATED RECEIVERS (i) General features (ii) Vibrator-operated receivers (iii) Characteristics of dry batteries 8. CAR RADIO (i) Interference suppression (ii) Circuit considerations (iii) Valve operating conditions 9. MISCELLANEOUS FEATURES (i) Spurious responses (ii) Reduction of interference (iii) Contact potential biasing (iv) Fuses (v) Tropic proofing (vi) Parasitic oscillations (vii) Printed circuits (viii) Other miscellaneous features 10. REFERENCES
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CHAPTER 36. DESIGN OF F-M RECEIVERS 1. F-M RECEIVERS (i) Comparison with A-M (ii) Aerial and r-f design (iii) Local oscillator design (iv) I-F amplifier (v) F-M detection and A-M rejection 2. F-M/A-M RECEIVERS (i) R-F section (ii) I-F amplifier (iii) General considerations 3. REFERENCES
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CHAPTER 37. RECEIVER AND AMPLIFIER TESTS AND MEASUREMENTS 1. A-M RECEIVERS (i) Introduction (ii) Definitions (iii) Equipment required (iv) Measurements and operating conditions (v) Measurements (vi) Tests 2. F-M RECEIVERS (i) Definitions (ii) Testing apparatus
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(iii) Test procedures and operating conditions (iv) Receiver adjustments (v) Performance tests 3. AUDIO FREQUENCY AMPLIFIERS (i) Equipment and measurements (ii) Tests 4. MEASUREMENTS ON COILS (i) Measurement of coefficient of coupling (ii) Measurement of primary resonant frequencies of aerial and r-f coils (iii) Measurement of distributed capacitance across coils 5. REFERENCES
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PART 7: SUNDRY DATA CHAPTER 38. TABLES, CHARTS AND SUNDRY DATA 1. UNITS (i) General physical units (ii) Electrical and magnetic units (iii) Photometric units (iv) Temperature 2. COLOUR CODES (i) Colour code for fixed composition resistors (ii) Colour code for fixed wire wound resistors (iii) Table of R.M.A. colour code markings for resistors (iv) Colour code for moulded mica capacitors (v) Colour code for ceramic dielectric capacitors (vi) Colour code for i-f transformers (vii) Colour code for a-f transformers and output transformers (viii) Colour code for power transformers (ix) Colour code for loudspeakers (x) Colour code for chassis wiring (xi) Colour code for battery cables (xii) Colour code for metallized paper capacitors 3. STANDARD RESISTORS AND CAPACITORS (i) Standard fixed composition resistors (ii) Standard fixed wire wound resistors (iii) Fixed paper dielectric capacitors in tubular non-metallic cases (iv) Metal encased fixed paper dielectric capacitors for d.c. application (v) Standard fixed mica dielectric capacitors (vi) Standard ceramic dielectric capacitors (vii) Standard variable capacitors (viii) Standard variable composition resistors (ix) Standard metallized paper dielectric capacitors (x) Standard electrolytic capacitors (xi) References to standard resistors and capacitors 4. STANDARD FREQUENCIES (i) Standard frequency ranges (ii) Frequency bands for broadcasting (iii) Standard intermediate frequencies 5. WAVELENGTHS AND FREQUENCIES (i) Wavelength-frequency conversion tables (ii) Wavelengths of electromagnetic radiations 6. STANDARD SYMBOLS AND ABBREVIATIONS (i) Introduction (ii) Multipliers1363 (xxxix)
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(iii) Some units and multipliers (iv) Magnitude letter symbols (v) Subscripts for magnitude letter symbols (vi) Magnitude letter symbols with subscripts (vii) Mathematical signs (viii) Abbreviations (ix) Abbreviations of titles of periodicals (x) References to periodicals (xi) References to standard symbols and abbreviations STANDARD GRAPHICAL SYMBOLS PROPERTIES OF MATERIALS AND CHEMICAL AND PHYSICAL CONSTANTS (i) Properties of insulating materials (ii) Properties of conducting materials (iii) Composition of some common plastics (iv) Weights of common materials (v) Resistance of a conductor at any temperature (vi) References to properties of materials (vii) Chemical and physical constants REACTANCE, IMPEDANCE AND RESONANCE (i) Inductive reactances (ii) Capacitive reactances (iii) Impedance of reactance and resistance in parallel (iv) Impedance of reactance and resistance in series (v) Resonance (vi) Approximations in the calculation of impedance for reactance and resistance in series and parallel (vii) Reactance chart SCREW THREADS, TWIST DRILLS AND SHEET GAUGES (i) Standard American screws used in radio manufacture (ii) B.A. screw threads (iii) Whitworth screw threads (iv) Unified screw threads (v) Drill sizes for self-tapping screws (vi) Wood screws (vii) Twist drill sizes (viii) Sheet steel gauges TEMPERATURE RISE AND RATINGS FUSES CHARACTERISTICS OF LIGHT; PANEL LAMPS (i) Visibility curves of the human eye and relative spectral energy curves of sunlight and tungsten lamp (ii) Velocity of light (iii) American panel lamp characteristics GREEK ALPHABET DEFINITIONS DECIMAL EQUIVALENTS OF FRACTIONS MULTIPLES AND SUB-MULTIPLES (i) Numerical values (ii) Factorials WIRE TABLES LOGARITHM TABLES TRIGONOMETRICAL TABLES Hyperbolic sines, cosines and tangents LOG SCALES AND LOG SCALE INTERPOLATOR (xl)
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