charter cable with dvr works good but if i use a splitter and run 1 cable to the dvr and 1 to the back of my tv. the signal gets weak and the tv is pixely. i would like to do this and just switch imputs. sometimes i like to record 2 shows and still be able to watch 1. if i watch the tv on the cable direct to the tv i can still record 2 on the dvr. if i amplify the signal before the splitter will it help?