The books, Electronic signals and systems: television, stereo, satellite TV, and automotive by Stan Prentiss, and Digital video and audio broadcasting technology a particle engineering guide by Walter Fischer provide sufficient information that is relevant to the research question. Stan Prentiss is one of the leading writers in the field of engineering.
In his book Electronic signals and systems: television, stereo, satellite TV, and automotive, he explains to the reader the process of signal transmission and reception. He targets students and anyone who interested in learning the basics of signal transmission from a broadcaster to the screen of a television.
Prentiss has writer several books on the topic of signal transmission and reception. These have been augmented by research that he has conducted on the same topic. In addition, it has been published by TAB books, a publishing company that publishes academic books.
On the other hand, Walter Fischer is a prolific writer who has authored several books in the field of engineering. In his book Digital video and audio broadcasting technology a particle engineering guide, he takes a similar approach to that of Prentiss to explicate the process of signal transmission and reception. The book is published by TAB books, a publisher with a positive reputation for publishing educational books.
Fischer uses a language that is simple to understand. Therefore, he targets both professionals and non-professionals who are interested in engineering as a scientific discipline. This source is authentic and relevant because it has been cited by many professionals in many leading universities around the world when writing their dissertations.
Transmission of television signals
Fischer (1961, p.87) gives an overview of signal transmission by stating that a transmitter tower transmits signals in form of audio and video components that are relayed in form of a carrier wave. The transmitter tower modulates the two components into one unit for ease of transmission. He further explains what modulation involves.
Modulation is the addition or removal of certain components in the signal in order to facilitate transmission. Prentiss (1991, p.193) adds to this by stating that modulation is carried out to eliminate any chance of interference between the video and audio component. Amplitude modulation is used to modulate the video component while frequency modulation is used to modulate the audio component.
Prentiss (1991, p.193) discusses modulation in digital televisions by stating that phase modulation is utilized. When two signals share the same timing when they are transmitted, they are said to be in phase. If not, they are out of phase. Transmission is done at very high frequencies (VHF) and ultra high frequencies (UHF) because at these frequencies, TV signals can travel long distances (Fischer, 1961, p.91).
In addition, signals can easily penetrate structures thus improving reception. Before transmission, several requirements are fulfilled. The video line resolution of the video signal is set and the cycling speed is determined (Fischer, 1961, p.96).
In addition, the speed of frame display is set in order to enhance reception. An important aspect of transmission is signal compression. Signals are compressed in order to improve transmission and to avoid loss of integrity during transmission.
First, a video camera takes a picture of a certain object at a certain recommended frame rate (Fischer, 1961, p.98). Secondly, the camera turns the object into pixels of different intensity and color. Thirdly, the pixels are paired with synchronisation signals to improve reception and display (Prentiss, 1991, p.145). This results in a generation of a composite video signal that is then transmitted.
Transmitters possess gadgets that convert transport stream into signals that are conveyed in both the audio and video format. Transmitter towers convey three main types of signals depending on type and frequency of transmission. These include antenna signals, satellite signals, and cable signals (Prentiss, 1991, p.147). Antenna signals are conveyed from radio transmitters.
They are significantly weak and a television antenna must be close enough to a broadcast tower in order for it to receive a signal that is strong enough to display images and produce sound.
Satellite signals are transmitted from a broadcaster to a satellite in space, and then to a dish that acts as a receiver. The dishes must be in line with a conveying satellite in order to receive signals without interference. Transmission of satellite signals usually occurs at very high frequencies.
As such, satellite signals behave like light waves. They can travel long distances without losing their integrity (Prentiss, 1991, p.99). On the other hand, certain signals are converted to electrical signals to improve the speed of transmission. The main advantage of antenna signals is that they do not lose their integrity during transmission unlike cable signals that do.
Reception of television signals
After signals are transmitted over air, the antenna or receiver mounted a television set receives them (Prentiss, 1991, p.134). Antennas perform two main functions. These include reception and amplification of signals. TVs contain special gadgets that convert received signals into a form that enables them to be displayed on a screen.
Quality of signal reception depends on the type of television set that receives it. For example, a satellite TV uses a receiver to convert signals into video and sound (Prentiss, 1991, p.137). On the other hand, modern TVs have inbuilt receiving units that eradicate the need for special receiving units. After a signal is received, it is decoded by the receiving unit and separated into video and sound components for display.
The receiver converts the received TV programs that are in form of waves into signals that are displayed as images (Prentiss, 1991, p.142). TVs possess display devices that are referred to as Cathode Ray Tubes (CRTs).
CRTs convert television signals into visible light for enhanced display. According to Prentiss (1991, p.107), a CRT contains steering coils that transmit the signal that is converted into an electron beam to the screen. TVs also contain sound devices that turn electrical signals into sound.
Conclusion
Transmission of television signals involves transmission of both audio and video components from a transmitter. The transmitter modulates the two components into one unit for ease of transmission. The signal is conveyed to the atmosphere in form of a carrier wave that is conveyed over air and received by an antenna or receiver mounted on a TV. TVs have inbuilt receiving units that eradicate the need for a special receiving unit.
After a signal is received, it is decoded by the receiving unit and separated into two components: video and sound. The video component is displayed on the screen while the sound component is transmitted to the sound device. The two books used in the research provide sufficient information that covers the research topic satisfactorily.
References
Fischer, W 1961, Digital Video and Audio Broadcasting Technology a Particle Engineering Guide, TBA Books, New York.
Prentiss, S 1991, Electronic Signals and Systems: Television, Stereo, Satellite TV, and Automotive, TBA Books, New York.