We get Time Warner cable on a commercial account with no cable boxes in our housing track. We use our TV controller to change channels. About one third of us get poor/snowy reception on the lower channels 4,5 and 6 while on the higher channels 8 and down the reception is great. Time Warner has been out several times and says it is our equipment. How can the reception be bad on certain channels and good on others. Would a HD cable box help?