They say that they hate bright lights.  If you can put a lot of lighting around your coop,  even solar ones that will come on when something enters the area would help if you don't have power that will help.  Also my Nite Guard lights are good for Foxes too.  I don't know if you have access to any websites that sell things such as coyote urine as that scares them away if you put it around the coop.  Also having a dog is a big help as they hate dogs even if it is not around the coop itself,  just the smell of one keeps them at bay.  Very strong fencing for your coop area will help deter them but they can climb so electric wire around the bottom of it would be a great way to stop them from climbing.  Good luck in protecting your flock.