In this report on television I will discuss television signals, the components the make up a television, and how a television produces the picture and sound for the final output.

The sound carrier is at the upper end of the spectrum. Frequency modulation is used to impress the sound on the carrier. The maximum frequency deviation is twenty-five kilohertz, considerably less than the deviation permitted by confessional FM stereo. As a result, a TV sound signal occupies less bandwidth in the spectrum than a standard FM broadcast station. Stereo sound is available in TV, and the multiplexing method used to transmit two channels of sound information is virtually identical to that used in stereo transmission for FM broadcasting.

The picture information is transmitted on a separate carrier located 4.5 MHz lower in frequency than the sound carrier. The video signal derived from a camera is used to amplitude modulate the picture carrier. Different methods of modulation are used for both sound and picture information so tha

The I and Q color signals are also called the R - Y and the B - Y signals as the combination of the three color signals produces the effect of subtracting Y from the R or B signals. The phase of these signals with respect to the original 3.58 MHz subcarrier signal determines the color to be seen. In many TV sets an extra phase shift of 57 degrees is inserted to ensure that maximum color detail is seen. There is still 57 degrees between the I and Q signals but their position is moved 57 degrees. The reason for this extra phase shift is that the eye is more sensitive to the color orange. If the I signal is adjusted to the orange phase position better detail will be seen. Because of the frequency of the subcarrier, the sidebands produced during amplitude modulation occur in clusters that are interleaved between the other sidebands produced by the video modulation.

At the same time the voice or sound signals frequency modulate a carrier that is amplified by class C amplifiers and fed to the same antenna by way of the diplexer. The resulting VHF or UHF signal travels by line-of-sight propagation to the antenna and receiver.

A picture tube is a vactume tube called a cathode-ray tube (CRT).Both monochrome and color picture tubes are available. The tube is housed in a bell shaped glass enclosure. A filament heats a cathode that emits electrons. The negatively charged electrons are attracted and accelerated by positive-bias voltages on the elements in an electron gun assembly. The electron gun also focuses the electrons into a very narrow beam. A control grid that is made negative with respect to the cathode controls the intensity of the electron beam and the brightness of the spot it makes.

Around the neck of the picture tube is a structure of magnetic coils called the deflection yoke. The horizontal and vertical current linear sawtooth waves generated by the sweep and synchronizing circuits are applied to the yoke coils, which produce magnetic fields inside the tube that influence the position of the electron beam. When electrons flow, a magnetic field is produced around the conductor through which current flows. The magnetic field that occurs around the electron beam is moved or deflected by the magnetic field produced by the deflection coils in the yoke. Thus the electron beam is sweep across the face of the picture n tube in the interlaced manner.

The R, G and B signals also contain the basic brightness or luminance information. If the color signals are mixed in the correct proportion, the result is the standard B&W video or luminance Y signal. The Y signal is generated by scaling each color signal with a tapped voltage divider and adding the signals together. The Y signal is made up of 30 percent red, 59 percent green and 11 percent blue. The resulting Y signal is what a B&W TV set will see.

The video signal described so far contains the video or luminance information, which is a black and white version of the scene. To add the color detail, this is done by dividing the light in each scan line into three separate signals, each representing one of the three basic colors, red, green or blue.

To recover the sound part of the TV signal a separate sound IF and detector section are used. The sound and picture IF signals are fed to a sound detector circuit. This is a nonlinear circuit that heterodynes the two IFs and generates the sum and

Some common words found in the essay are:
VHF UHF, KHz Dividing, United TV, B&W TV, Fundamentals Television, Additional TV, picture tube, color signals, video signal, sync pulses, 358 mhz, electron beam, mhz subcarrier, 358 mhz subcarrier, red green blue, tv sets, green blue, tv signal, coils picture tube, horizontal sync pulses, color signals transmitted,
Approximate Word count = 6955
Approximate Pages = 28 (250 words per page double spaced)