In 2009, television transmissions switched from analog to digital, which provided crisper television signals. If you still have an analog television, though, you need a digital TV converter box to receive any of these signals. In the past, it was enough to have an antenna on the roof to pick up local channels. When the signals switched to digital, those antennas stopped working. With the digital-to-analog TV converter box, you get a much better picture than you do with the old antenna. If you have an HD television, then a regular converter box may not give you exactly the picture you want. An HD digital TV converter box works with HD televisions to translate the signal properly so you see HD channels in all of their glory, just as you hoped when you purchased your high-definition television. With the vast inventory on eBay, you can find a digital TV converter box for all of your older televisions. Some are even so small that you will barely notice they are there.