How Does a Portable Digital TV Work?

by Quinten Plummer


Portable DTVs receive digital signals from television station towers by adjusting to the station's broadcast frequency. For example, if a station's broadcast frequency is 126mhz, you would have to match your digital TV to that frequency. The device then demodulates, or decodes, the signal and displays the results on your screen.

The Signals Channels

Digital signals require less bandwidth than analog signals. The efficiency of digital broadcast allows stations to do other things with the freed bandwidth. With the extra bandwidth, some channels provide interactive enhancements like Internet polls and maps. The extra space also allows broadcasters the ability to produce sub-channels. Sub-channels can be used to broadcast HD versions of the same channel or cover out of market sporting events.

The Screen

Portable DTVs use LCD screens, or "liquid crystal displays." Images are produced via an electric current that stimulates the "liquid crystals" that are pressed between to glass panes. Light from a bulb at the back of the screen is filtered through the crystals. As the electricity morphs crystals, different hues and color are refracted and reflected from the light--producing moving pictures on your screen.

About the Author

Quinten Plummer began writing professionally in 2008. He has more than six years in the technology field including five years in retail electronics and a year in technical support. Plummer gained his experience in music by producing for various hip-hop acts and as lead guitarist for a band. He now works as a reporter for a daily newspaper.