[John Candle]

It is always correct to ground the coax that is connected to the antenna using a coax grounding block. The first choice of ground location is the house ground rod. A second choice is a cold water pipe , the cold water pipe must be real metal not plastic and the cold water pipe must be real metal that goes down into the ground out to the water main or to the well. Do Not connect to a hot water pipe. Grounding the shield part of the coax using a coax grounding block directs unwanted signals such as but not limited to - multipath - to ground. All manner of grounding supplies can be found at place like Homedepot and Lowes.