I have a 16 cam system that I have upgraded to hdtvi using the coax in place. I am having trouble getting a 2mp ptz to work. The coax cable is about 60m long with 3 breaks. If I disconnect the last 20m the picture is clear on my tester but connecting the last 20m massively distorts the picture. All the other 2mp cams work fine and the ptz cable has been tested with one of the other cams. Is this likely a ground loop issue or do I need a booster? I haven’t got one yet to test. The ptz is powered locally.