I have a couple of these Systems 9000 boxes and a larger Syntor x9000 radio(?) I have never played with these and really cant find a lot of information on them. Attached are some pictures of what I have. Where do I interface the serial cable to? Is that the actual radio? I believe these may just be siren boxes, I have some of the panels needed for the radios as well. But one of the 9000s boxes has a coax connector so I am really not sure on these. You guys know more then I do. Just want to maybe get a couple of these running for fun (photos through imgur since they are too large)