Your cable TV signal will be improved if it is properly grounded. This means the ground cable, usually green, is connected to a ground rod that goes deep into the earth.
Cable Internet Speed
I was hoping that the cable internet speed would also improve by reconnecting ground. But I saw no improvement in that. I ran a test at speedtest.net.
The cable internet connection here gave these test results:
9.75 Mb/s download
0.25 Mb/s upload
A proper ground connection improved my TV signal, but not my internet speed.