I usually leave some slack at the top weather it is a loop or not. It will give some extra cable just incase you need to change the connector up there. It is better to have some slack to put a new connector on than replace the coax because its too short. I am currently using a antenna with the so239 connector on it but thinking of replacing it with one that comes with the N connector, so I would have the cable up there to change my coax to a N connector.