What the OP needed was an Actiontec 3000N01 Coax network and wireless network extender.
This device will extend the wireless radios with both 2.4 Ghz & 5Ghz signals using exsiting coax. (Splitter 1 Leg TV other to device. )
While I use both Powerline and MOCA with success the MOCA is superior. No interference, higher speeds and more stable.