Cable Television
Television and Video
HDTV

How is a TV picture sent to your home?

User Avatar
Wiki User
September 12, 2011 11:56PM

If the tv signal is coming to your house by a tv antenna on the roof, then a special very wide band radio signal is used. Your classic tv tuner can pick one tv channel out of all the different channels that are in the air. Same idea is used for satellite dishes except the signal has been converted to be a very high microwave frequency, and you need a satellite receiver to convert the microwve signals back to regular tv tuner signals.

If you have cable tv, the similar tv signals come to your house, only they get to your tv through a wire and there is no antenna used.

The signal for a single channel is about 4-5 megahertz wide. That's like an FM radio station channel that goes all the way from 100 to 105 on the FM dial, for a single channel. You could only squeeze 3 or 4 channels in to whole FM radio band.

The tv pictures are sent one at a time, about 30 per second, so it looks like smooth motion.

To visualize the structure of a tv signal: At about 100 mhz would be special pulses and codes to start the picture. From 100.5 to 104.5 would be the thousand of color dots you see on the picture tube, and the briteness of each dot. Then at 104.5 you would find the soundtrack which very much like an FM radio station, infact you can listen to the audio without watching the picture, on some radios.

Every second many slightly different pictures are flashed before your eyes on the screens and all you see is the smooth tv motion pictures.

Hope this helps a little.