LG sets have this. It can be a bit of a pain too. They have a habit of updating the software and re-enabling the power output from the RF socket.Common for sat dish inputs, but I have never come across that on the terrestrial antenna socket, though I did wonder if that might be a possibility. To work and allow other sets on the other outputs to get a signal, it would need to be able to be set to always on, even when that TV was off.