Don is correct. In my former work I installed radio systems on boats and considered 5-years trouble-free operation "full life cycle". I sealed those cables with a layer of scotch-30 annealing tape with Scotch 33+ over that. The boats were in 27 to 45 foot class so subject to considerable saltwater spray. We also had two 200-foot oil well support vessels on Cook Inlet in Alaska.
My Ham Radio use of LMR-400 gets about ten years life, even with super diligent sealing. The aluminum tape shield is subject to corrosion in presence of moisture. Using true hardline like LDF cables will outlast LMR cables. Why they are used in commercial radio sites. I live two miles from Cook Inlet.
My main VHF/UHF transmission line is 120 foot of LDF7-50A which is 1-5/8 inch in diameter and cost me $1.00/foot new surplus (got a 160-foot remnant). It has about 0.27 dB/100 foot loss at 150-MHz. I get about 5w on 1296 with 15w input over a 170-foot combined run of LMR-600 & LDF7-50A.
Coax does not live forever - unless used as a dummy load (LOL)
73, Ed - KL7UW 35-years experience in 2-way communications (FCC 2nd class with Marine Endorsement)
This has been an interesting chain of posts and I have copied it for distribution at our club.? Thanks. I will continue to follow it.
However, to those out there that think that you can eliminate water in coax with proper sealing, you are only delaying the inevitable, especially if you live in a humid climate like New Orleans