A) Moisture contamination
Moisture contamination is a common cause of failure in coaxial cables. However, what causes moisture contamination? In our own case, we have had it caused by chewing! No, we do not have a penchant for dining on coaxial cable. However, it seems that squirrels and dogs do. On one occasion, a squirrel attacked and chewed the sheath of the coaxial cable that ran up the side of a large maple tree. On another occasion, our dog was bored and decided to dig and chew on about 3 feet of Bury Flex coaxial cable. Fortunately, neither animals were hurt.
Expensive lessons on both occasions since the cables were useless once the jacket was penetrated. The next time around we buried conduit to provide an underground run from the entrance to the point just below the antenna. The cable is now safe from the elements, dogs, and lawn mowers.