I agree with Al, you should at least have the cap. I couldn't change polarities, when I checked the cap it had dry rotted and had a good size hole in it and the feedhorn was full of wasp. Couple of squirts of Raid and all was well. I used a piece of nylon stocking until I got a new cap. As for a cover, I leave it uncovered during the summer and put a plastic bag over it during the winter. Used to use duct tape, but the plastic ties are much better (eaiser to get off). My reasoning is that rain will run off and dry pretty quick during the summer, but snow will stick to it and could be there the duration of the winter.