Television Engineering - Dec 2013
Electronics & Telecomm. (Semester 6)
TOTAL MARKS: 80
TOTAL TIME: 3 HOURS (1) Question 1 is compulsory.
(2) Attempt any three from the remaining questions.
(3) Assume data if required.
(4) Figures to the right indicate full marks. 1(a) What do you understand by positive and negative modulation? Justify the choice of modulation for TV transmission.(5 marks) 1(b) What are the video amplifier section requirements in order to preserve the video signal contents.(5 marks) 1(c) Why is vestigial side-band transmission used for transmission of TV picture signals?What is the need for vestigial correction?(5 marks) 1(d) What are the various streaming media protocols?(5 marks) 2(a) Show that a total channel bandwidth of 7MHz is necessary for successful transmission of both picture and sound signals in the location of picture and sound signal carrier frequencies.Why is the sound carrier located 5.5 MHz away from the picture carrier/(10 marks) 2(b) Explain the following terms w.r.t colour transmission:
Additive and subtractive Mixing(10 marks) 3(a) In an image orhticon
Why is the electron Beam given a cycloidal motion before it hits the target plate?
Why is electron beam velocity brought close to zero on reaching the target plate?
What is the function of the decelerator grid?(10 marks) 4(a) List the important equipment needed for trouble shooting a TV receiver.Suggest the common procedure to be followed while troubleshooting a TV receiver.(10 marks) 4(b)(i) Draw a neat block diagram of a sync separator and explain its operation.(5 marks) 4(b)(ii) What are the essential requirement to be satisfied to make a colour TV system fully compatible with monochrome system?(5 marks) 5(a) Explain at least four test signals used for testing /aligning a TV receiver.(10 marks) 5(b) Describe the working of a Digital TV system.(10 marks) 6(a) Draw the block diagram of NTSC encoder and decoder.Explain the function of each block.(10 marks) 6(b) What do you mean by interface error?How does it affect the quality of picture?Calculate the percentage interface error when the second field is delayed by 16μs
retrace time may be assumed to be negligible.(10 marks) 7(a) Describe the working of a CCTV system.(6 marks) 7(b) What are the advantages of geostationary satellites?Explain the terms 'uplink' 'downlink' as used in satellite system.(6 marks) 7(c) What is the function of a degaussing coil in a TV receiver?(4 marks) 7(d) What are the advantages of interface scanning?(4 marks)