Like many in rural areas, the OTA antenna installed w/ my Voom system only got 2 of 4 networks and not even both of them all the time. Because of neighborhood covenants, I decided to put a large HD antennae in the attic.I installed a Radio Shack VU120XR VHF/UHF/HD/FM antenna in the attic and ran the cable into the same combiner(?) switch where Voom runs thier antenna into beneath the satellite dish. The antenna not only doesn't work for local channels it Blocks the satellite signal! The satellite icon on the Motorola receiver turns form green to red- when I disconnect the antenna from the cable, it turns green again. As a reality check, I tried to hook up a set of rabbit ears to the cable in the attic- it blocks the satellite signal too! With nothing connected to the end of the cable the satellite signal is fine. Can anyone explain whats' going on?? I thought there was essentially no difference between so-called HD antenna's like the ones Voom uses and a regular antenna.