Recently purchased Raymarine 18 inch raydome for my 40ft Tashiba. Here is my question: I obviously have to drill a hole in the mast for the 5/8 inch cable. What kind of strain relief do I use to hold the weight of the cable and also keep the cable from chafing on the hole I drilled in the mast? The only thing I could find was called Cable Clam. I am wondering if this is the proper procedure. I would hate to find out that two months down the road the cable would chafe and cut and then short out. Any comments would be appreciated.