Is there a way to combine or split a siganl feed through one cable from the dish into sat 1 & 2? Or do I need to run a separate cable. Thanks

Just hooked up a new HR21-DVR to switch out my HD20 hooked it up and not recieving all my HD channels and the C sat has very little or no signal. I'm replacing the cables tonight and see if that helps. TS is making a service call tomorrow unless the cables help. Sorry if this is a repeated post...