Fourstringburn is 110% correct on that ground plane for a mobile antenna. I don't care who it's made by. They simply don't work. Wilson makes them too. Snake Oil!! Spend the money on other things, good coax and connectors like Jazzsinger said. Amphenol connectors are great, the 83-1SP-15RFX, are the ones with the reducer. Nickel plated brass body and silver tipped. Coax wise, Beldin, times microwave, Davisrf, and a few others make good rg8x and lmr240uf. Worth the investment IMO. Spend what you can on the antenna system as a whole. Some mounts are better than others. Everything these guys are telling you is right. Good luck and hope you get it sorted.