How Television Broadcasting Works

Jordan Guyette
4/4/08 Period 2
Mrs. Lechinger


How Does Television Get Broadcasted?
(Lets Find Out)

Television, can get broadcasted and heard throughout the world but you should be most familiar with these first 5; through an antenna, VCR or DVD players connected to antenna terminals, large 6-12 feet satellite dishes located at the top of your house that also connect to antenna terminals, or smaller 1-2 feet with the same properties of the larger one of the two. Those are the main five ways to get a signal on your TV set. That is how Television is seen, but how would we hear it?

A typical TV uses 4MHz of bandwidth, but as you add in sound, a little something called vestigial bandwidth requires 6MHz. As in doing that, the FCC allows three band of frequencies in the radio spectrum, also allowing TV channels:
• 54 to 88 MHz for channels 2 to 6
• 174 to 216 MHz for channels 7 through 13
• 470 to 890 MHz for UHF channels 14 through 83


As you have probably been wondering, since I brought it up, is how you can hear a TV. Well, there is also a complicated way to explain how you get sound, but for my readers, I will simplify it for you. If your VCR, DVD or TV has a yellow composite video jack, you have then probably noticed that there are separate sound jacks right next to it. The result of this is to show that sound and video are completely separate on an analog television.

Now lets get a little more detailed. The image source is what you see on the screen without the sound. The image source can be a movie, reality show, any TV show, but it is usually filmed with a camera or a flying spot scanner. Again with the sound, we already have the image but what’s seeing something without hearing it? The source of the audio is the TV programming whether coming from a movie TV show, news channel, etc. the sound can come from mono, stereo, or even digitally remastered surround sound. Now, we wouldn’t have any of this mesmerizing image or audio if it weren’t for the transmitter and receiver. Let’s start with the transmitter. The transmitter is what sends the image and the audio In a radio frequency from the station, to a combined analog, and then to your house. Which is where the receiver comes in? The receiver practically tells you what it does in the name, it receives the frequencies and lets you watch and listen in perfect harmony. The saying goes, you cant have one without the other. There are many chains this almost never-ending story, but we are getting to the end. Now we have the display device. The display device will usually be a TV, or a monitor. Inside, there is the technology that to turn the electrical signals received into visible light. The end is coming, we shall now move onto the sound device. The sound device is usually built in speakers or speakers that accompany the display device in the package. The sound device does the same thing the display device does but just with sound. The technology inside lets it turn the electrical signals into sound waves to play the audio that goes with the display.


http://electronics.howstuffworks.com/tv12.htm
http://www.hdradio.com/how_does_hd_digital_radio_work.php
http://www.tech-faq.com/television-broadcasting.shtml