first of all did you put your own connectors on the cable if so are they store bought twist on, are they crimp, are they compression? have any of the service call techs pulled the wall plates and checked the fittings, do they have suck outs? have they checked for kinks in the cable? when you ran you own cable did you step on it in the attic? Did the die-electric get crushed? If you change the ohms on coax it is ruined, coax must be 75 ohms. you could have good signal despite all these potential problems. another problem is you do not know if your provider is all digital, are they analog? this creates more questions. i know i know. you are thinking it is digital because i have a dct. not true. too many varying factors for you average diy cable guy. Cable is no longer just hooking shit up. it has become much more than that. feel free to ask away i will answer your questions.