Monochrome And Colour Television R R Gulati
Content
1. Elements of a Television System ........... 8
1.1 Picture Transmission ......................... 8
1.2 Sound Transmission ......................... 11
1.3 Picture Reception ..... 11
1.4 Sound Reception ....... 12
1.5 Synchronization ........ 12
1.6 Receiver Controls ..... 13
1.7 Colour Television ...... 13
2. Analysis and Synthesis of Television Pictures ........ 16
2.1 Gross Structure ........ 16
2.2 Image Continuity...... 16
2.3 Number of Scanning Lines .............. 19
2.4 Flicker ........................ 21
2.5 Fine Structure .......... 25
2.6 Tonal Gradation........ 31
3. Composite Video Signal ......................... 36
3.1 Video Signal Dimensions ................. 36
3.2 Horizontal Sync Details ................... 39
3.3 Vertical Sync Details ........................ 41
3.4 Scanning Sequence Details.............. 47
3.5 Functions of Vertical Pulse Train ... 49
3.6 Sync Details of the 525 Line System ......................
49
4. Signal Transmission and Channel Bandwidth ........ 54
4.1 Amplitude Modulation ..................... 54
4.2 Channel Bandwidth ......................... 56
4.3 Vestigial Sideband Transmission .... 57
4.4 Transmission Efficiency ................... 58
4.5 Complete Channel Bandwidth ........ 59
4.6 Reception of Vestigial Sideband Signals ................
60
4.7 Frequency Modulation ..................... 62
4.8 FM Channel Bandwidth................... 66
4.9 Channel Bandwidth for Colour Transmission ....... 67
4.10 Allocation of Frequency Bands for Television Signal
Transmission .................... 68
4.11 Television Standards ........................ 68
5. The Picture Tube ............. 74
5.1 Monochrome Picture Tube ............... 74
5.2 Beam Deflection ....... 76
5.3 Screen Phosphor ....... 79
5.4 Face Plate .................. 79
5.5 Picture Tube Characteristics ........... 82
5.6 Picture Tube Circuit Controls ......... 82
6. Television Camera Tubes ...................... 86
6.1 Basic Principle .......... 86
6.2 Image Orthicon ......... 89
6.3 Vidicon ....................... 94
6.4 The Plumbicon .......... 97
6.5 Silicon Diode Array Vidicon ............. 99
6.6 Solid State Image Scanners ........... 100
7. Basic Television Broadcasting ........... 106
7.1 Television Studio .... 106
7.2 Television Cameras ........................ 108
7.3 Programme Control Room ............. 110
7.4 Video Switcher ........ 111
7.5 Synchronizing System .................... 115
7.6 Master Control Room (MCR) ......... 117
7.7 Generation of Amplitude Modulation ...................
118
7.8 Television Transmitter .................. 119
7.9 Positive and Negative Modulation ........................
120
7.10 Sound Signal Transmission ........... 122
7.11 Merits of Frequency Modulation ... 123
7.12 Generation of Frequency Modulation ...................
125
7.13 Stabilized Reactance Modulator.... 127
7.14 Generation of FM from PM............ 128
7.15 FM Sound Signal .... 130
8. Television Receiver ....... 134
8.1 Types of Television Receivers ........ 134
8.2 Receiver Sections .... 135
8.3 Vestigial Sideband Correction ....... 139
8.4 Choice of Intermediate Frequencies .....................
140
8.5 Picture Tube Circuitry and Controls ....................
143
8.6 Sound Signal Separation ............... 143
8.7 Sound Section ......... 144
8.8 Sync Processing and AFC Circuit .........................
146
8.9 Vertical Deflection Circuit ............. 146
8.10 Horizontal Deflection Circuit ........ 147
9. Television Signal Propagation and Antennas ....... 150
9.1 Radio Wave Propagation................ 150
9.2 Television Signal Transmission .... 152
9.3 Interference Suffered by Carrier Signals .............
153
9.4 Preference of AM for Picture Signal Transmission .....................
155
9.5 Antennas ................. 156
9.6 Television Transmission Antennas .......................
161
9.7 Television Receiver Antennas ....... 164
9.8 Colour Television Antennas .......... 170
9.9 Transmission Lines ........................ 173
9.10 Attenuation Pads .... 178
10. Television Applications ........................ 182
10.1 Television Broadcasting ................. 182
10.2 Cable Television...... 182
10.3 Closed Circuit Television (CCTV) .........................
186
10.4 Theatre Television .......................... 188
10.5 Picture Phone and Facsimile ......... 189
10.6 Video Tape Recording (VTR) ......... 189
10.7 Television via Satellite ................... 196
10.8 TV Games ................ 199
11. Video Detector ................ 210
11.1 Video (Picture) Signal Detection ... 210
11.2 Basic Video Detector ...................... 211
11.3 IF Filter ................... 213
11.4 DC Component of the Video Signal ......................
215
11.5 Intercarrier Sound.......................... 216
11.6 Video Detector Requirements........ 217
11.7 Functions of the Composite Video Signal .............
217
12. Video Section Fundamentals .............. 220
12.1 Picture Reproduction ..................... 220
12.2 Video Amplifier Requirements ...... 220
12.3 Video Amplifiers ..... 225
12.4 Basic Video Amplifier Operation ..........................
228
12.5 Comparison of Video Signal Polarities in Tube and
Transistor Circuits ........... 230
12.6 Relative Merits of Grid and Cathode Modulation of the
Picture Tube .............. 233
13. Video Amplifiers—Design Principles .......................
236
13.1 Vacuum Tube Amplifier ................. 236
13.2 High Frequency Compensation ..... 238
13.3. Low Frequency Compensation ...... 243
13.4 Transistor Video Amplifier ............ 245
13.5 Transistor Circuit Analysis ........... 246
13.6 Guidelines for Broad-Banding ....... 250
13.7 Frequency Compensation .............. 251
13.8 Video Driver ............ 254
13.9 Contrast Control Methods ............. 254
13.10 Screen Size and Video Amplifier Bandwidth ....... 257
14. Video Amplifier Circuits ...................... 260
14.1 Direct Coupled Video Amplifier .... 260
14.2 Problems of DC Coupling ............... 262
14.3 Partial DC Coupling ....................... 264
14.4 Consequences of AC Coupling ....... 267
14.5 DC Reinsertion ....... 269
14.6 AC Coupling with DC Reinsertion ........................
270
14.7 The AC Coupling .... 271
14.8 Video Preamplifier in an IC Chip .........................
272
15. Automatic Gain Control and Noise Cancelling Circuits .............
276
15.1 Advantages of AGC ........................ 276
15.2 Gain Control of VT and FET Amplifiers...............
277
15.3 Gain Control of Transistor Amplifiers ..................
278
15.4 Types of AGC .......... 279
15.5 Various AGC Systems .................... 281
15.6 Merits of Keyed AGC System ........ 285
15.7 Delayed AGC........... 285
15.8 Noise Cancellation .......................... 286
15.9 Typical AGC Circuits ..................... 287
15.10 AGC Adjustments ........................... 291
16. Sync Separation Circuits ..................... 296
16.1 Sync Separator—Basic Principle ..........................
296
16.2 Sync Separator Employing a Pentode ..................
298
16.3 Transistor Sync Separator ............. 299
16.4 Noise in Sync Pulses ...................... 300
16.5 Typical Tube Sync Separator Circuit ....................
302
16.6 Transistor Noise Gate Sync Separator .................
303
16.7 Improved Noise Gate Sync Separator ..................
304
16.8 Sync Amplifier ........ 305
17. Sync Processing and AFC Circuits ... 308
17.1 Sync Waveform Separation ........... 308
17.2 Vertical Sync Separation ............... 309
17.3 Horizontal Sync Separation ........... 311
17.4 Automatic Frequency Control ....... 312
17.5 AFC Circuit Employing Push-Pull Discriminator .......................
313
17.6 Single Ended AFC Circuit ............. 316
17.7 Phase Discriminator (AFC) with Push-Pull Sawtooth ................
318
17.8 DC Control Voltage ........................ 319
18. Deflection Oscillators ........................... 324
18.1 Deflection Current Waveforms...... 325
18.2 Generation of Driving Voltage Waveforms .......... 327
18.3 Blocking Oscillator and Sweep Circuits ...............
329
18.4 Multivibrator Deflection Oscillators .....................
335
18.5 Complementary-Symmetry Relaxation Oscillator ......................
340
18.6 Sine-Wave Deflection Oscillators ..........................
341
19. Vertical Deflection Circuits ................ 346
19.1 Requirements of the Vertical Deflection Stage .... 346
19.2 Vacuum Tube Vertical Deflection Stage ...............
354
19.3 Transistor Multivibrator Driven Vertical Output Stage .............
356
19.4 Blocking Oscillator Driven Output Stage.............
357
19.5 Transformerless Output Circuit.... 358
19.6 Vertical Sweep Module .................. 359
19.7 The Miller Deflection Circuit ......... 360
19.8 Integrated Circuit for the Vertical System ..........
362
20. Horizontal Deflection Circuits ........... 366
20.1 Horizontal Output Stage................ 366
20.2 Equivalent Circuit .......................... 367
20.3 Horizontal Amplifier Configurations ....................
370
20.4 Vacuum Tube Horizontal Deflection Circuit ........ 370
20.5 Sequence of Operations .................. 377
20.6 Horizontal Amplifier Controls ....... 378
20.7 ‘S’ Correction ........... 381
20.8 Improved Line Output Circuit ...... 382
20.9 Output Circuit Stabilization .......... 384
20.10 Transistor Horizontal Output Circuits .................
385
20.11 Transistor Line Output Stage ....... 386
20.12 Horizontal Combination IC-CA.920 ......................
388
20.13 Horizontal Deflection Circuits in Colour Receivers.....................
391
20.14 SCR Horizontal Output Circuit ..... 394
21. Sound System.................. 400
21.1 Sound Signal Separation ............... 400
21.2 Sound Take-off Circuits ................. 401
21.3 Inter-carrier Sound IF Amplifier ..........................
403
21.4 AM Limiting ............ 404
21.5 FM Detection .......... 405
21.6 FM Sound Detectors ....................... 408
21.7 Sound Section Integrated Circuits ........................
420
21.8 Audio Output Stage ........................ 423
22. RF Tuner .......................... 428
22.1 Tuner Operation ..... 428
22.2 Factors Affecting Tuner Design .... 429
22.3 Basic Coupling Circuits ................. 430
22.4 Tuner Circuit Arrangement .......... 434
22.5 Types of Tuners ...... 436
22.6 Various Sections of a VHF Tuner..........................
438
22.7 Electronic Tuning ........................... 441
22.8 Vacuum Tube Tuner....................... 444
22.9 Transistor Tuners ........................... 445
22.10 UHF Tuners ............ 447
23. Video IF Amplifiers ....... 452
23.1 Video IF Section...... 452
23.2 IF Amplifiers ........... 454
23.3 Vacuum Tube and Solid-State IF Amplifiers ....... 455
23.4 Vestigial Sideband Correction ....... 460
23.5 The IF Sound Signal ...................... 460
23.6 Adjacent Channel Interference ..... 460
23.7 Video IF Amplifier Circuits ........... 463
23.8 IF Sub-systems Employing ICs ..... 465
24. Receiver Power Supplies ..................... 472
24.1 Low Voltage Power Supplies ......... 473
24.2 Types of Rectifier Circuits ............. 475
24.3 Heater Circuits ....... 478
24.4 Voltage Regulators ......................... 479
24.5 Low Voltage Power Supply Circuits .....................
482
24.6 High Voltage Power Supply ........... 483
24.7 Stabilized Thyristor Power Supply .......................
484
24.8 Switch Mode Power Supply (SMPS) .....................
485
25. Essentials of Colour Television ......... 490
25.1 Compatibility .......... 490
25.2 Natural Light .......... 491
25.3 Colour Perception ........................... 492
25.4 Three Colour Theory ...................... 493
25.5 Luminance, Hue and Saturation... 495
25.6 Colour Television Camera ............. 497
25.7 The Luminance Signal ................... 498
25.8 Values of Luminance (Y) and Colour Difference Signals
on Colours ................. 502
25.9 Polarity of the Colour Difference Signals .............
503
25.10 Colour Television Display Tubes ... 505
25.11 Delta-Gun Colour Picture Tube .... 505
25.12 Purity and Convergence................. 507
25.13 Precision-in-Line (P.I.L.) Colour Picture Tube ....
510
25.14 The Deflection Unit ........................ 513
25.15 Purity and Static Convergence Adjustments ....... 514
25.16 Dynamic Convergence Adjustments .....................
516
25.17 Trintron Colour Picture Tube ........ 519
25.18 Pincushion Correction Techniques .......................
521
25.19 Automatic Degaussing (ADG) Circuit...................
522
25.20 Grey Scale Tracking ....................... 523
26. Colour Signal Transmission and Reception ........... 528
26.1 Colour Signal Transmission .......... 528
26.2 Bandwidth for Colour Signal Transmission ......... 530
26.3 Modulation of Colour Difference Signals.............. 530
26.4 Weighting Factors .......................... 533
26.5 Formation of the Chrominance Signal .................
535
26.6 NTSC Colour TV System ............... 537
26.7 NTSC Colour Receiver ................... 541
26.8 Limitations of the NTSC System ..........................
544
26.9 PAL Colour Television System ...... 544
26.10 Cancellation of Phase Errors .............. 546
26.11 PAL-D Colour System .... 547
26.12 The PAL Coder .......... 549
26.13 PAL-D Colour Receiver .................. 551
26.14 Merits and Demerits of the PAL System ..............
559
26.15 SECAM System ........ 559
26.16 Merits and Demerits of SECAM Systems ............ 563
27. Remote Control and Special Circuits .......................
566
27.1 Remote Control ....... 566
27.2 Electromechanical Control System .......................
569
27.3 Electronic Control Systems ........... 571
27.4 Electronic Touch Tuning................ 573
27.5 Frequency Synthesizer TV Tuner .........................
574
27.6 Automatic Fine Tuning (AFT) ....... 575
27.7 Booster Amplifiers .......................... 578
27.8 Automatic Brightness Control ....... 579
27.9 Instant-on Circuitry ....................... 580
27.10 Picture-tube Boosters ..................... 582
28. Alignment and Servicing Equipment .......................
586
28.1 Multimeter .............. 586
28.2 Vacuum Tube Voltmeter (VTVM) .........................
588
28.3 Digital Multimeters ........................ 590
28.4 Cathode Ray Oscilloscope (CRO)... 591
28.5 Video Pattern Generator................ 599
28.6 Sweep Generator .... 601
28.7 Marker Generator .......................... 603
28.8 The Colour Bar Generator ............. 606
28.9 Vectroscope ............. 611
28.10 High voltage Probe ......................... 613
29. Receiver Circuits and Alignment ...... 616
29.1 Monochrome TV Receiver Circuit .........................
616
29.2 Monochrome Receiver Alignment .........................
618
29.3 Television Test Charts ................... 626
29.4 All IC Television Receivers ............ 628
29.5 Alignment of Colour Receivers ...... 630
30. Receiver Servicing ........ 638
30.1 Trouble Shooting Procedure .......... 638
30.2 Trouble Shooting Monochrome Receivers ............ 641
30.3 Servicing of Various Functional Blocks ................
644
30.4 Trouble Shooting Colour Receivers .......................
663
30.5 Servicing Circuit Modules ............. 663
30.6 Safety Precautions in Televisions Servicing ........
666
Appendices ......................... 671
A. Conversion Factors and Prefixes ......................
670
B. Transient Response and Wave Shaping .......... 671
C. Television Broadcast Channels ........................
679
D. Satellite Television .................... 681
Index ........ 685
