Kenwood CS-1352 Instruction Manual

shown in Fig. 15B. The distance between cor-responding points on the horizontal axis for the twow a v e f o r m s then represents the phase shiftbetween the two waveforms. In this case, the zerocrossover points of the two waveforms are com-pared. It is shown that a difference of 1 div exists.This is then interpreted as a phase shift of 4 5 ° .Television Servicing:Many of the video servicing procedures can be per-formed using single-trace operation. These areoutlined later in the applications section coveringsingle-trace operation. One of these procedures,viewing the V I T S (vertical interval test signal), canbe accomplished much more effectively using adual-trace oscilloscope. A s outlined in the single-trace applications section and as shown in Fig. 19and 26, the information on the Field 1 and Field 2vertical blanking interval pulse is different. This isshown in detail in Fig. 19. Also, because the os-cilloscope sweep is synchronized to the verticalblanking interval waveform, the Field 1 and Field 2waveforms are superimposed onto each other.With dual-trace operation, the signal informationon each blanking pulse can be viewed separatelywithout overlapping. Fig. 18 indicates the os-cilloscope control setting for viewing the alternateV I T S .Most network television signals contain built-intest signals (VITS) that can be very valuable tools introubleshooting and servicing video equipment.The V I T S can localize trouble to the antenna, tuner,IF or video sections and shows when realignmentmay be required. The V I T S signal is being used insome television receivers for automatic color cor-rection.The V I T S signal is transmitted during the verticalblanking interval. On the television set, they can beseen as a bright white line above the top of the pic-ture, when the vertical linearity or height is ad-justed to view the vertical blanking interval. (On T Vsets with internal retrace blanking circuits, theblanking circuit must be disabled to see thesesignals.)The transmitted V I T S is precision sequences ofspecific frequencies, amplitudes and waveshapesa s shown in Fig. 16. The television networks usethe precision signals for adjustment and checkingof network transmission equipment, but the techni-cian can use them to evaluate television set perfor-mance. The first frame of V I T S at the " B " section(line 18) in Fig. 16 begins with a white reference16Fig. 16 V I T S signal. Fields 1 and 2( M U L T I - B U R S T )V E R T I C A L B L A N K I N G I N T E R V A L ( N O : 1 ~ N O . 2 1 )H O R I Z . S Y N C . P U L S EV E R T I C A L B L A N K I N G I N T E R V A L ( N O . 2 6 3 ~ N O . 2 8 2 )( M U L T I - B U R S T )F I E L D IF I E L D 2F I E L D I & 2L I N E No.17 No. 18No.279 No.280No. 17No.279No. 18No.280