I would install a cable tie mount just above the hole and use a cable tie to support the cable at that point. The cable should be going up into the hole, rather than down, to minimize the amount of water that flows down the cable into the mast. The hole should be lined with a rubber or plastic grommet to prevent the cable's jacket from chafing against the aluminum.
If the cable is thick enough, long enough and heavy enough, it may be worth getting some spectra cord, say 1/8" diameter and twisting the cable about it and taping it off every few feet, then attaching the upper end of the spectra cord to the same cable tie mount. This would allow the spectra cord to take the weight of the cable, rather than the cable itself. They do this in other cable bundles I've worked with.
A cable clam is generally used to run a cable through the deck and prevent the cable entry from allowing water through, while giving a large enough opening so the terminal end of the cable can pass through the opening.
07-16-2008 08:03 AM
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.