In the summer of 2009, TV stations in the United States stopped broadcasting in analog format and started broadcasting digitally. Digital TV signals allow such things as high-definition TV (HDTV), as well as serving as a more efficient means of broadcasting in general. Understanding how analog and digital broadcasting works is key to understanding why the transition took place.
Analog
Analog TV signals are sent on a wave analogous to the original signal. It works well, but takes up a lot of space on the bandwidth.
Digital
Digital TV signals are sent as a complex series of bursts--each identical to the other--which forms a code of 1's and 0's. String enough code together, and you can recreate the images and sound of the TV show.
The Change
Digital is preferred over analog because it takes up much less space on the bandwidth. The extra space can be used both to produce a sharper, clearer image, and for emergency services.
TVs
All TVs sold after March 2007 in the United States need to include a digital tuner, allowing them to receive digital signals.
Converters
Older analog TVs require a digital converter to receive the new signals. Converters plug into the TV like a cable box and shift the signals into an analog format that the older TV can read.
Tags: analog format, Digital signals, signals Converters, signals sent, space bandwidth