Keep reading. You're about to discover just about the most unlikely thing you could ever expect to make out of cardboard.

As a high-definition TV owner, you're looking for the easiest and least expensive way to get your local network channels. You may have realized that this is something you don't have to pay your cable TV provider for. Crisp, clear, digital, high-definition signals are available for free from your local TV stations: All you need is the right antenna.

But HDTV antennas can be expensive: $40 to $70 for a good indoor model. This is one of the best HDTV antenna designs ever, and also the least expensive, because you will make it yourself using cardboard and foil.

Here's a secret you won't hear from an antenna manufacturer: The TV signals themselves don't care what the antenna is made from, as long as the correct arrangement of electrical conductors is present. With this antenna, that's aluminum foil. As outrageous as it may sound, this antenna can be just as effective and powerful—or more so—as any other antenna, no matter the cost or construction.

I have taken some of the best antenna designs I could find and modified, experimented, built, and rebuilt them until I had the best performing HDTV antenna I have ever tested. They just happen to be made out of cardboard.