I have an Internet modem/router device connected to a 20 foot LMR400 coaxial cable which uses N-to-N type connectors to connect to a 10 foot LMR400 cable, which is then connected into an omnidirectional antenna for cellular Internet reception. This is all on top of a very large metallic structure (a big metallic tower basically)
I've been told that I shouldn't let the N-type connectors touch any of the metal on the structure, as that creates a "ground loop" and additional paths to ground. I'm supposed to put rubber on the connectors or at least wrap them in electrical tape.
But I don't quite understand the electrical/physical reasons as to why the connectors should not touch any metal. Why does this cause a problem? I've read something about "reference" and "potential" being messed up by multiple paths to ground... could someone explain what people mean by that?