I'm replacing a Slingbox Tuner with possibly a SlingBox PRO-HD. I don't have a cable set top box. Can I connect the SlingBox PRO-HD directly to the wall with a coax cable and then to the TV with a coax cable? Does it have to be special coax signal? In other words, can I swap out the Slingbox Tuner with the SlingBox PRO-HD with the same type of connecting cables? Thanks.