I have split a exist cable to support another tv . one be get basic cable with no problem . the original hdtv really suffer from the split . I be get virtually no channel beyond basic cable through hdtv cable box . I hook up the Motorola 2-port signal booster in minute . I do have to do a cold restart of the cable box for it to sense the improved signal . the signal be now better than it ever be . I be really glad I buy this .