If your TV is less than 5 years old, you don't need a converter box. The TV has built in DTV tuner. You will need to find in the menus where to set the input, and change it to "air" or "antenna" depending on your model, and then do a channel scan (with the antenna attached of course). Check your manual if you still have it. The flat antenna may, or may not, work for you depending on your location. If you would post the URL for the "radar plot" from
TV Fool here, we would be able to help you with antenna selection and pointing for best reception.