Index

Al electrodes 211 Aspect ratio 14,246 Additive mixing 3 Attenuator, aerial 260-1 Aerial, acceptance angle 251, 252 Automatic chrominance control (a.c.c.) amplifier 260 112,113,130 attenuator 260-1 Automatic phase control (a.p.c.) 130 bandwidth 254 cable 257-8 (B'-Y') signal see Colour difference dipole 250-4 signal directivity 250 Back porch 25-6 front-to-back ratio 254 Bandwidth see also Sidebands gron 254,255,256 aerial 254 group coding 260 chrominance 18,85 impedance 254 colour difference signal 19, 85 isolating circuit 46-7 i.f. 58,60,61 i 246 log-periodic 256 luminance 85 matching 250 TV channel 17 polar diagram 251,252,253, video 12-17,79,246 255,259 Beam limiting 90,96-9 polarisation 251, 252 Beat pattern see Interference signal splitter 261-2 Bistable 134 Yagi array 253,255 Black level, clamp 80-3,124-5,247, A.F.C. (automatic frequency control) see also D.C. level restoration 50,69-72 in video waveform 25-6, 78, A.G.C. (automatic gron control), 80-1 delayed 107-8 Blanking, burst 114 fault-finding 108-9 flyback 90,95-6,170,176,195 forward 106-7 Boost h.t. 194,200,263,281, see also gated (keyed) 77, 104-5 Efficiency diode Lf. 107-8 Brightness control 82,83,90,91-3 mean level 101-2 Burst signal see also Sub carrier peak level 102-4 regeneration reverse 106-7 amplifier 126,127 tuner 48,49,107-8 blanking 113,114 Alignment see I.F. amplifiers discriminator 127, 128 Aquadag coating 212,234 formation of 23,32 289 290 Index

Burst signal (cont). Colour control see Saturation gating 126,127 Colour difference drive 89,124-5 phase 23 Colour difference signal see also Chrominance signal Cable, aerial 257-8 amplifiers 124-5 Camera, arrangements in colour TV (B'-Y') 10,29,30 11-12 bandwidth 19 tube 6-7 demodulation 119-21,113 Casco de amplifier 64 de-weighting 89,122 Cathode modulation of c.r.t. 74, 88, formation of 10, 11 122-3 (G'-Y') 11,29,30,89,121 Cathode ray tube (c.r.t.) 42-3 (R'-Y') 10,28,29 colour 210,211 waveforms see Colour bar signal convergence see Convergence weighting of 22,32,33 correction Colour killer 87,113,132,137 delta gun 213-16 Colour tubes see Cathode ray tube electrodes 211 Colours, complementary 4 grey scale see Grey scale tracking mixing of 2-5 in-line gun 216-17 primary 4 linearity (of picture) 212, 213, Contrast control 93-5, 102, 103, 114 s"ee also Field time base, Line Convergence correction 212,215-16, time base 218-19 monochrome 210, 211 adjustments 236, 239-40, pincushion distortion see Pin• 240-2 cushion correction circuit diagrams 219-25 precision in-line (PIL) 217,238, delta gun tube 215, 219-23, 244 240-2 purity 212,237-8 differential 219,222,241 replacement of 213,234 dynamic 216,219-25,240-2, safety precautions 233-4 247 shadowmask 214 field 219-23,224-5,240-1 Trinitron 217-18 'in-line'tube 223-5,239,242 voltages 79,125,211 lateral 216,221 waveforms see Colour bar signal line 221-3,224,240-1 Ceramic filter 146, 149 matrixed 219,241 Chrominance signal (chroma), amplifiers precision in-line (PIL) tube 240 112-19 radial 216,221 bandwidth 19,112 static 216,220,239-40,241, delay line 116-19 245,247 formation of 20-2,32-3 waveforms 218-19 modulation of 120 Cross-hatch signal 219,245,247 phase errors 22-3,114-16 Cross-over distortion 150-1, 175 phasor diagram 31,32,115 Crowbar circuit 285 U and V signals 21-2,31,32, Crystal oscillator 129 116 waveforms see Colour bar signal Darlington pair 271 Clamp circuit see Black level clamp D.C. amplifiers 79-80,151-2 Colour bar signal 27,245,248 D.C. level see also Black level waveforms 27,28-33,122-3 of convergence waveform 223 Index 291

restoration of 80-1,90 of 194,201-4 of video waveform 78-9 overwind 201,202,203 Decoder, colour 40-1,110-42 rectifiers 201, 202 De-emphasis 147-8,150 tuning 203-4 Degaussing, automatic 232-3 Electronic smoothing 271 manual 237 Encoder, colour 20-2 Delay line, chrominance 116-19 Equalising pulses 34,35,160 luminance 85-6, 248 Demodulator see Detector Fault-finding, in a.f.c. 72 Desaturated colours 5,30,123-4 a.g.c. 108-9 Detector see also Discriminator colour decoder 140-2,245,246, a.f.c. 70-2 247 a.g.c. 102-3 d.c. amplifiers 108 chrominance 112 field time base 179-80 coincidence 148-50 I.C.s 142-3 colour difference 119-21 Lf. strip 65 diode 74-5 line time base 206-9 Foster-Seeley 70, 71 luminance rtages 86 Lf. 50 power supplies 286 phase 128,182-5 sync. separator 157,178-9,245 quadrature 77, 148-50 tuner 57 ratio 146-7 video amplifiers 108 slope 148 Field time base 42,164-70,171-6, sound 146-50 176-80 suppressed carrier 20, 119-21 amplifiers 168,175-6, 176-8 synchronous 75-9, 119-21 fault-finding 179-80 video 39,73-9,98 linearity 161-4, 170, 175, 180 Diac 275 oscillators 165-7,168,171-4 Dichroic mirrors (prisms) 11 switched mode 178 Differentiating circuits 160-1 synchronisation 34-5, 159-60, Diode, attenuator 113 168,173 detector 74-5 waveforms 162,169-70,174, dropper 265 175 mixer 50,74 Fifth harmonic tuning 203 modulator 230-1 Flashover, tube 198,233 rectifier 266-8 Flyback, blanking 90,95-6, 170, 176 Diode split winding 202 tuning see line time base Diplexer 257 Flywheel synchronisation 181-5 Dipole 250-4 Frame see Field time base Discriminator, burst 127-8 Frame frequency 15 line sync. pulse 181 Frequency interleaving 18-19 Driveramplifier 99,119,151,175, Front porch 25-6 190 (G'-Y') signal see Colour difference Efficiency diode see also Boost h.t. signal semiconductor 193,195,197, Gating see A.G.C., Burst 204 Ghost images 248,250,254,258,259 valve 200 Grid modulation of C.Lt. 89,125 E.H.T.(extra high tension), generation Grey scale tracking 90,231-2,243-4 292 Index

Hanover bars 115,119,133,142,247 output transformer 194-5, Highlights, picture 243 199-201 Horizontal deflectiDn see line time stabilisation 198-9 base synchronisation 34-5, 161, Hue 1,5 181-5 waveforms 162,185-6,190 I.C.s (integrated circuits), a.f.c. 71, 77 width control 194,197,198, a.g.c. 77 199,231,236,281 colour decoder 136-40 linearity see Cathode ray tube, Field fault-finding 142-3 time base, line time base field time base 176-8 linearity sleeve 212-13 line time base 185,189 L.O.P.T. see line time base, output luminance 92, 137-40 transformer power supplies 48,269,280-3, Luminance signal 5 285 amplifiers 85-7, 100, see also sound stages 149-50 Video amplifiers sync. separator 177 bandwidth 85,87 tuner control 48,54,55,56,57 delay line 85-6 video stages 75-7,92,137-40 formation of 11, 28 Ident signal 129, 130, 131, see also waveforms see Colour bar signal PAL switch I.F. amplifiers 39, 58-69 Matrix see Convergence correction, alignment 66-9 Encoder, (G'-Y') signal, R', G', B' response shaping 58-65 matrix Illuminant D 244 Mixer stage 50, 52-3, 74 Integrating circuits 157-60,191 Moire pattern 236 Intercarrier sound see Sound stages Multivibrator 165-7, 171-4 Interference signals 59,60,74, 75, 105, 107, 145, 148, 181, 277, see also Noise signal Negative feedback 63, 84, 151, 153, Interlace filter 164, 168 164,170,175 Interlaced scanning 15,180,247 Negative modulation 8-9, 73 Noise signal 9, 37, see also Interference Keystone distortion 231 signal N.T.C. see Thermistor Lecher bars 47,49,50,53 N.T.S.C. colour system 23 Umiting amplifier 69, 145 line frequency 26 Oscillator, blocking 166,167,189 line time base 41, 181-209, see also crystal 129 E.H.T. field see Field time base driver amplifier 190 Hartley 186-8 fault-finding 206-9 line see Line time base flyback tuning 191-2,193,194, multivibrator 165-7,171-4 195,200 subcarrier see Sub carrier linearity 161-4,194,197 regeneration oscillators 177, 185-9 tuner 50 output stage 192-5,195-8, Overcurrent protection 283-4 198-201 Overvoltage protection 284-6 Index 293

PAL colour system 22-3, 114 colours PAL-D 116 control 95,113-14,137 PALoS 116,119,137 S-correction 162-4,193,194,197,200 PAL switch 133-6, 140, 142 S.C.S. (silicon controlled switch) 173, Parabola waveform 170-5,218-19, 174,175,273 227,230 SECAM system 24 Peak white 8,25,26,122 Shadowmask 214,217 Phase errors 22-3, 24, 114-17 Shift, picture 213 Phasor diagrams 31 , 32, 115 Sidebands 15-17, 19, 59 Picture tube see Cathode ray tube Silicon controlled rectifier (SCR) Pincushion distortion 213,225-7 see Thyristor colour TV 225-31, 243 Simple PAL see P AL-S monochrome TV 213 Sound muting 57 correction transductor 227-9 Sound system 41 Positive modulation 8-9,73 amplifiers 145, 150-3 Pre-emphasis 147, 148 de-emphasis 147-8,150 Primary colours 4 detection 146-50 Protection circuits see Beam limiting, intercarrier principle 36, 144 Overcurrent protection, Overvoltage pre-emphasis 147, 148 protection, Voltage regulators Spark gaps 234 P.T.C. see Thermistor Stabilisation of e.h.t. 198-9,203, Purity correction 212,237-8 279,284 height 170 Quadrature modulation 20,120 power supplies see Voltage Quiescent current 150,152 regulators width 198-9,281 Raster 41 Stability, amplifier 61, 63 Raster correction see Convergence Striations 198,208 correction, Pincushion distortion Sub carrier , colour, burst see Burst Reactance stage 129, 186 signal Rectifier circuits 194,265-8 choice of frequency 19 Reference oscillator 125-30 dot pattern 19, 60 Reflected signal see Ghost signal filter, notch 86-7 Remote control 55-7 90° phase shift 134, 140 R', G', B' amplifiers 82,83,87-9 regeneration of 125-30,137 R', G', B' drive 87-9,100,111,122-24 suppression of 19-20 R', G', B' matrix 38,40,88,122,140 Surface acoustic wave filter 64 Ringing 65,189,190,198,282, see Swinging burst 23 also Stability Switch-off spot suppression 91-3 Switched mode field time base 178 Safety 69, 209, 283-7 Switched mode power supplies 272-83 aerial installation 46-7 Synchronising pulses 7, 25, 34-5, cathode ray tube 233-4 157-61 components 209, 287 Synchronous demodulation 75-9, legal implications 44, 209, 287 119-21 power supplies 44 Sync. pulse separator 41, 154-7, 176, X-rays 209,234 178-9 Saturation 5, see also Desaturated noise gated 155-6 294 Index

Teietext 36,79,260 Video detector 39, 73-9 Test cards 245-8 diode circuit 74-5 Thermistor 170,175,233,264 filtering 75,77 Third harmonic tuning 203 polarity of 73 Thyristor 273 synchronous 75-9 line time base 204 Video recorder 185 power supplies 273-7 Video signal, black level of 25-6, 78, Tilt control 219 80-2 Time constant 158,162 d.c.levelof 78, 79 Tint control 24, 232 formation of 7,8-9,13-14, Transductor 227-9 32-3 Triad 214 polarity of 73 Trinitron 217-18 time/amplitude relationship 25 TripIer 202 Vision buzz 145, 148 Tuner 37 Vision carrier, channel allocation 17, a.f.c. 50 58,59 a.g.c. 48,49,107-8 negative modulation 8-9 diode switching 52-3 positive modulation 8-9 electronic see varicap Vision Lf. 58 fault-finding 57 Voltage multipliers 201-2 integrated 50-3 Voltage regulators, chopper circuit mecha'nical 47-8,50 277-8 mixer 50,52-3 I.C. 48,269,280-3 oscillator 50,52-3,58 line output 278-80 remote control 55-7 protection circuits 275-6,282, r.f. amplifier 46-7, 48-50 283-6,288 touch control 53-5 series transistor 269-71, 277-8, u.h.f. 46-50 284 varicap 48-50 shunt transistor 272, 278-83 v.h.f. 50-3 switched-mode 272-83 thyristor 273-7 U and V signals see Chrominance signal Zener diode 268-9

Varicap diode 48 Waveforms see Colour bar signal, Con• VDR (voltage dependent resistor) 91, vergence correction, Field time base, 93,168,198,199,269 Line time base, Pincushion distortion Vertical deflection see Field time base Weighting factors 22, 33 Vestigial sideband transmission 17, 59 Wideband amplifiers 61 Video amplifiers 39,79-85,99-101, Width control 194, 197, 198, 199, 231, see also Luminance amp., R', G', B' 236,281 amp. Wobbulator 67 bandwidth 79 brightness control 82,83,90, X-rays 209,234 91-3 X-tal see Crystal oscillator contrast control 93-5 d.c. amplification 79-83 Y-signal see Luminance signal fault-finding 108 frequency response 60,74,79, Zener diode 268-70,272,276,284, 83-5,90,246 285