I have an Ac unit just out my window i could put an antenna on. But it cant be too big. Would a small jpole or discone antenna work? If so which one would i recieve the best results with?
If you already have a horizontal metal plate outside your window a simple 1/4 wavelength antenna on a ground plane is a good option too.
An issue with all antenna's is that large objects in the neighbourhood of the antenna (walls and windows in your case) influence the direction sense of the antenna. Don't be surprised if moving your antenna a few inches horizontally makes the difference between noisy and clear reception.