625 line T. V. The frequency of the video signal is 0 Hz (DC) to 5 MHz. Hence double bander, M transmission requires 10MHz bandwidth. But it is not possible to experimentally design a filter through which the sideband can be sharpened. Hence the experimental band band width is more than 10 MHzShe lives. A guard band of 0.5 megahertz is also transmitted with each sideband. Therefore, the total side band becomes II MHz, the band width increases by 0.25 MHz due to the voice signal, so the total side band becomes 11.25 MHz She lives. A guard band of 0.5 megahertz is also transmitted with each sideband. Therefore, the total side band becomes II MHz, the band width increases by 0.25 MHz due to the voice signal, so the total side band becomes 11.25 MHz She lives. A guard band of 0.5 megahertz is also transmitted with each sideband. Therefore, the total side band becomes II MHz, the band width increases by 0.25 MHz due to the voice signal, so the total side band becomes 11.25 MHz.
Total Bandwidth (DSB) System |
Channel bandwith
The sound carrier is always at the end of the fully radiated upper side and is 5.5 MHz away from the picture carrier. This is the place where the least interference occurs, between the two signals. F . M . The sound signal receives a spectrum of frequencies around 75 MHz, around the sound carrier. TV. A 0.25 mega Haj guard band is also sent on the sound carrier for the channel. The total channel band is thus found at 7 MHZ, and it exhibits 4.2 MHz band pass saving in each channel when compared to 11.25 MHz, which is required for the double side band signal.
CCIR TV Channel side band spectrum |
T.V. Channel and band
It is not possible to use acoustic or vision for long distance communication. Rather we use radio wire or cable for this. Different channels are used for this. The term channel is used to denote the frequency range assigned to a particular communication facility. Like - TV In channel number 1, D.D. Sports channel etc.
Band means the path through which the effective frequency passes and in which the performance level of the system's functioning remains satisfactory. The satisfactory range is determined in a convenient manner on an appropriate basis. The band is basically known by the path or group of frequencies.
Video bandwidth
In 625 line systems, 40 lines are lost in vertical retrace and active scanning lines are reduced from 625 to (625-40) 585. Taking the kell factor 0.7, the vertical resolution becomes 585, 0.7 or 410 lines. Thus active or effective lines; The vertical resolution remains at 410, and the horizontal resolution maintains a uniform magnitude. Thus their approximate ratio is 4: 3. Thus the black and white vertical lines will be the following for matching horizontal resolution
= 410× 4/3 ≃ 546
It is equivalent to 273 cycles of the Elementary Area of Black and White. Retrace time for a horizontal line.
fH = 1/fH = 2/15,625
= 64 μs
Maximum baseline video frequency
f max = Active Number of Line × Cal Factor × Aspect Ratio/2 × Line forward scan perior
fmax =Na×k×a/2Hf
tHf(TH - TR)
= 52 μs
TR is the time used for blatting
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