Coaxial cable is always suspect, especially if you didn't buy it in bulk and install the connectors yourself. Almost all actual failures are at a connector, and those occur simply because they're not installed properly. That includes a lot of 'factory preassembled' coaxial cable assemblies. The 'factories' don't do the kind of job I do. Also, re the LDG tuner, remember the tuner can't tune itself when you're receiving; it can only 'tune' and tune correctly when you transmit, and that requires a carrier and not SSB. If you use the tuner in line and don't transmit, there's no way to know where it's tuned and if mistuned, they can introduce a whole lot of loss.