I installed an ota antenna to pick up local digital channels and want to feed a 622 and a 722. If I run direct to either of the receivers I pick up 14 channels on each. If I use a splitter I only pick up 2. The splitter says from 5-800mhz. Do I need something with a higher frequency or need to get a preamp splitter? I am running about 25' feet of cable to the splitter and another 25' from the splitter to the receivers. The cable is 3ghz tested. Thanks for any info anyone has.