Line noise can be very tough to fix. Usually some hardware on the pole needs to be replaced or tightened. If you can locate the pole with a portable airband or AM broadcast radio then you will be ahead of the game. Then you have to get friendly with your local power company.
Another thing that people have tried is lightly banging on the pole with a sledge hammer. But I am not advising that.
(It usually does not work, and even if it does, it's usually only a temporary fix.)
Dave