TV (Television) stations are equipped with all necessary devices which interdependently work to make the broadcasting a live or recorded program through satellites or air. Although billions of people around the world watch TV daily but above 95% of them don't know that how the technology works. In this article, we will learn what a TV station is and how a it works.
What is a TV Station?
As we discussed it in the beginning that a TV station is comprised of several devices or components which make a program to be telecast or broadcasted. TV stations are equipped with different devices and components which make it possible to broadcast videos and audios aggregately. The major components, which make a TV station working, are discussed below:
Image or Video Source
Image or video source is the most fundamental component of a TV station. This source may be a movie, pre-recorded program or any device like video cam for capturing the images. Flying spot scanners can also be used to capture the images.
We hear the sound and image combinely in our TV sets, but both of these are not recorded with a single device. Audio recorders are used to record the sound separately. The sound can be recorded as mono, stereo or digitally depending on the recording device. Thus sound is recorded and added to the movie or video to make it complete before telecasting or broadcasting.
Video and Audio Processing
Video and audio are processed after retrieving them. Several devices are used by experts to perform the task. The sound and video are processed in a way that they could be watched and listened comfortably by the audience.
When the sound and video are recorded, retrieved and processed, now the next step is to broadcast or telecast them over air or through satellites. Transmitters are equipped on boosters which convert the video and audio signals into specific formats like electromagnetic waves etc. then transmit them. In a such a way, the video and audios are scattered and sent to the receivers.
TV sets receive the signals and convert them back into video and audio signals which are seen by the audience. If a program is broadcasted over air, then only a TV set can be used to receive the signals, but if the signals are telecasted through satellites, then DVB (Digital Video Broadcasting) receivers along with TV sets are needed to watch the programs.
FTA and Encrypted TV Programs
There are both FTA (Free to Air) and encrypted TV stations in the world. An FTA TV station broadcasts the programs without encrypting them and anyone can watch the broadcasting using the required devices. Alternatively, encrypted TV programs are mostly paid and signals of such broadcasting are encrypted using different technologies, so common TV sets and receivers can't decode them. Such type of broadcasting is accessible to the customers only.
TV programs are broadcasted by a TV station in two basic forms which are discussed below:
- Broadcasted TV: This type of broadcasting is usually made through a ground transmitter and the signals can be accessed for free. Broadcasted TV is sometimes referred as terrestrial broadcasting. The programs can be sent to short distances only using this type of broadcasting.
- Satellite TV: Satellite TV is the next type of broadcasting which is done through satellites. This type of broadcasting is digitally processed and the signals can be received distantly by a dish-antenna and a DVB receiver.
Transmission bands vary from country to country. These bands are different frequencies in which a program is broadcasted. Following basic bands are used in transmitting a TV progam:
- Band I: It is a lower-bandwidth band which cannot carry much information. It means that a TV program broadcasted in this frequency band will of very poor quality. Band I is not used to broadcast the TV programs commonly. Audios or radio signals can be broadcasted using this frequency band.
- Band II: Band II is much stronger than Band I but still it is not strong enough to carry the high quality data. Such type of frequency bands are usually used to broadcast the radio signals over the satellite.
- Band III: TV programs are broadcasted on the frequency bands higher than III. Band III is allocated a bandwidth of 54 to 88 MHz, so it can carry enough information. i.e. video and audio can be carried together.
- Band IV: Band IV frequencies are much stronger and they can carry even more details. Most TV stations broadcast their programs in Band IV. The frequency range of Band IV is between 174 to 216 MHz.
- Band V: These bands are much powerful and can carry the bandwidth between 470 to 890 MHz. This type of broadcasting delivers quality content to its audience.
- VHF and UHF: VHF (Very High Frequency) and UHF (Ultra High Frequency) are the most powerful signals which can carry the maximum possible details. These are very powerful frequencies which can travel long and can penetrate the obstacles like walls etc. also.
PAL and NTSC
PAL and NTSC are two standards which are followed in broadcasting of TV programs. PAL stands for Phase Alternating Lines while NTSC stands for National Television Standard Committee. These standards vary from country to country.
This was an introduction to TV stations that how they work and how they telecast or broadcast the programs. I hope that this has helped you understand what the basics of TV broadcasting are.