TV goes black for a few minutes then comes back on... happens 3-4 times a day

I just upgraded to X1 last month after having the basic Comcast/Xfinity cable for 20 years. Ever since upgrading, the TV picture/sound goes out randomly 3-4 times a day (It works perfectly 90% of the day). Sometimes it'll go a day or two with no problems if I'm lucky. It stays off for a few minutes, then comes back on. Sometimes there will be an error code, RDK-03033, "we're having trouble connecting to the internet..." I don't even have internet with Xfinity (or even cable internet for that matter). Everything is securely tightened. The old cable box I had worked perfectly for 20 years using the same exact connection. 

Does the X1 box require a stronger or different signal or connection? Right now, the coaxial cable coming from the street is actually a double cable, with one end going into the cable box and the other going to nothing. This is the same exact double coax cable that was used for TV in this house in the 80's. 

Does anyone have any idea what could be going on? Maybe I need to combine those two ends of the cable into an adapter of some sort to get a stronger signal? Maybe I need a whole new cable coming from the street? I'm hoping there's an easy fix I can do before calling a tech.

Any info would be appreciated. Thanks.