antenna signal on existing home coax?

[kjs5555]

hi all - just starting the liberating process of cutting out digital cable from my life. I will be adding an antenna in the attic for starters. Ideally I am hoping to use the existing coax throughout my house to get the signal in 4 rooms with TVs.

I also plan to keep my Comcast cable for high speed broadband and phone in the house

Questions:
1. Can I somehow put the antenna signal on to the same coax home network? Will it interfere with the Comcast broadband?
2. If the signals don’t interfere with each other, how do I get the antenna signal on the coax cable along with the Comcast signal?
3. Can one antenna service my entire house (4 TVs, rough house size 3500 sq ft 2 stories so I have some lengthy coax runs)?

[GroundUrMast]

Don't connect your antenna system to the cable TV network.

Cable TV is a closed system, meaning no signal is to get in or out of the system. As a result, Cable TV networks are able to use frequencies that are assigned to licensed 'over the air' services including police, fire, ambulance and aircraft service.

If you connect an antenna to a cable TV system, you risk causing harmful interference to a variety of legitimate services.

You can disconnect any or all cables in your home from the cable TV network, then use those cables to distribute your antenna signal. Just leave the cable modem connected to the cable TV system.

[GroundUrMast]

If done with care (to avoid mixing cable company signals with OTA), there are technologies that allow you to run data over your OTA coax. You must use an amplifier or filter to prevent radiating a signal into the air via your antenna.

http://forum.tvfool.com/showthread.php?t=13034

[Battledad]

I did the same thing. Here's my experience:

Cable Internet (Comcast): I identified each outlet in the house and matched/labeled each in the box on the side of the garage. I then had Comcast connect to the feed that went to the room where the modem would go. Note: i do not use tv in the room where the modem is.

Next I set up my antenna and took the coax to the box where I attached it to a good splitter to which I attached the outgoing coax leads to the various rooms where I had TV's. I did add an amp (depending on the sigals, coax length, etc., you may or may not need an amp and/or of different boost +12; +18; +24).

Doing it this way I have no interference at all and using my wireless router connect to the TV's (either direct or through something like a Roku).