When television broadcasts make the digital switch next February, viewers with analog sets who rely on an antenna will need a converter box to view their favorite shows – or any shows.

Consumer Reports tested two dozen converters models on the market to see which ones worked the best.

Converter boxes are available for sale online, at electronics stores like Radio Shack and Circuit City, and at general retailers like Sears, Target and Wal-Mart.

All converters tested had the same basic features, including a remote control. Some also provided a comprehensive program guide or let you adjust the closed captioning to make it bigger and easier to read.

Consumer Reports found that the converter boxes it tested produced picture quality ranging from acceptable to outstanding.

So many factors can affect television reception that even the best converter box might not work in every situation.

"Where you live, the local terrain, the number of stations that are broadcasting in your area, signal strength and the type of antenna that you're using" all impact the picture you see, Consumer Reports' Jim Wilcox said.

Consumer Reports tests suggest that if you have trouble getting a picture, it is more likely related to location, antenna or set-up than to the converter box. To get the best picture, WRAL-TV engineers suggest adjusting your antenna, moving it to a different part of the room or getting a rooftop antenna.

One of the best performers in the tests was the Tivax STB-T9, which costs just $10 after the $40 coupons being offered by the federal government.