A is used ,which is suitably polarized to rectify either positive or negative peaks of the input signal. 9. Draw diagram of a monochrome TV receiver and briefly explain the operation of TV receiver. A black and white receiver has six main sections:- Tuner section, IF sub system ,Video section ,Audio section, Deflection and power supply. section: This section consists of RF amplifier ,mixer and local oscillator.It selects the desired channel signal from those picked up by the antenna and converts it into the IF band. IF subsystem: The IF subsystem includes IF section ,AGC circuit and video detector.The IF section provides large amplification to the weak IF signals and the video detector that follows IF amplifiers produces composite video and intercarrier FM sound signals. Video section: The Video signal is accorded large amplification and fed to the picture tube. Audio section: The sound associated with the picture is transmitted as an FM signal with a center frequency 5.5MHz above the station picture carrier frequency. The sound signal BW is only about 150Khz as compared to the large bandwidth of 5MHz for the picture signal. Sync separation and processing: The horizontal and vertical sync pulses that form part of the composite video signal are separated in the sync separator. The composite video signal is either taken from the video detector output or after one stage of video amplification. DC supplies: All the active devices ,ICs and picture tube need a dc source for their operation. Rectifiers are used to convert ac to dc and filters provided to eliminate ac ripple in the dc output. 10. Explain briefly the operation of IF subsystem. The IF subsystem includes IF section ,AGC circuit and video detector.The IF section provides large amplification to the weak IF signals and the video detector that follows IF amplifiers produces composite video and intercarrier FM sound signals. The factors that influence the choice of intermediate frequencies in TV receivers are: Image Rejection Ratio: Image rejection ratio is defined as the output due to desired station divided by output due to image signal. Pickup due to local oscillator radiation from TV receivers Image Frequencies should not lie in the FM band Interference or direct pickup from bands assigned for other services
A is used ,which is suitably polarized to rectify either positive or negative peaks of the input signal. 9. Draw diagram of a monochrome TV receiver and briefly explain the operation of TV receiver. A black and white receiver has six main sections:- Tuner section, IF sub system ,Video section ,Audio section, Deflection and power supply. section: This section consists of RF amplifier ,mixer and local oscillator.It selects the desired channel signal from those picked up by the antenna and converts it into the IF band. IF subsystem: The IF subsystem includes IF section ,AGC circuit and video detector.The IF section provides large amplification to the weak IF signals and the video detector that follows IF amplifiers produces composite video and intercarrier FM sound signals. Video section: The Video signal is accorded large amplification and fed to the picture tube. Audio section: The sound associated with the picture is transmitted as an FM signal with a center frequency 5.5MHz above the station picture carrier frequency. The sound signal BW is only about 150Khz as compared to the large bandwidth of 5MHz for the picture signal. Sync separation and processing: The horizontal and vertical sync pulses that form part of the composite video signal are separated in the sync separator. The composite video signal is either taken from the video detector output or after one stage of video amplification. DC supplies: All the active devices ,ICs and picture tube need a dc source for their operation. Rectifiers are used to convert ac to dc and filters provided to eliminate ac ripple in the dc output. 10. Explain briefly the operation of IF subsystem. The IF subsystem includes IF section ,AGC circuit and video detector.The IF section provides large amplification to the weak IF signals and the video detector that follows IF amplifiers produces composite video and intercarrier FM sound signals. The factors that influence the choice of intermediate frequencies in TV receivers are: Image Rejection Ratio: Image rejection ratio is defined as the output due to desired station divided by output due to image signal. Pickup due to local oscillator radiation from TV receivers Image Frequencies should not lie in the FM band Interference or direct pickup from bands assigned for other services
television___video_engineering.docx