Sorry to hear this Alan.
Make sure when you get your new antenna that they give you the right gasket and that it hasn't been crinkled. A friend of mine had to replace his and it still leaked due to the bad gasket.
I've been running the Cooper "Discoverer ST" for 10,000 miles and love them. They work better in mud and snow than the BFG AT Km2's they replaced. I'm running 235/86/16 Tall and Skinny.