Most antenna are broadband antenna, in order for them to receive VHF channels 2-13. The element of the antenna vary in length from short to long. The longest element is used for channel 3. After storms and high winds, the antenna can often suffer damage or have been moved. The longer elements are the ones that are generally damaged.
Many viewers choose to place their antenna in their attics.
Because most attics are small and cramped spaces, these tight spaces often do not allow the antenna to be aimed correctly. Some people will even break off the longer elements in order for them to swing the antenna around in attic to find the best aiming point. By removing these longest elements, they have removed the receiving elements for Channel 3.