English: Masts that carried VHF/UHF antennas from the 1970s and 80s had to be very strong in order to support the large antennas and their rotors. This made them difficult to take down when the owners switch to cable or satellite. More recently many have found a second life as masts for new generation antennas, like this example.
With the transition to digital television in the 2000s, most of the VHF channels were abandoned and moved to UHF. Additionally, UHF channels from 51 to 81 were also abandoned. This greatly reduced the total range of frequencies being used and allowed new antenna designs to be introduced, with the reflective array antenna, like this example, becoming the most popular. It is much smaller than the Yagi-Uda designs formerly used for UHF, as well as being somewhat less directional.
This particular example is an "8-bay" design, with eight bow-tie dipole antennas placed in two vertical groups of four each in front of two reflectors. The structure holding the two together, and acting as the mounting point to the mast, allows the two halves to be rotated in respect to each other. This is normally sold as a feature allowing signals from two different locations to be picked up, but in practice this rarely works in a simple fashion due to the complexity of the phase relationships between the two sides.