I have cable internet only (no tv). My house coax is split into every room. I want to feed a cable modem from house coax, then I want to pipe video from the internet on channel 4 back into my house coax. Can it be done?
You need to re-word what you are trying to do, it really does not make any sence here. What internet is on channel 4? "Channel 4" would be a TV channel, and video does not just go on the cable from the internet, you are getting just the data that moves on it. To actually see "video" from the internet connection you need a modem and a computer connected to that modem. To share that in the house, you setup up a modem, hook up a router to that modem and connect the computers to the router with ethernet or wifi connections.
Thank you. I would feed a cable modem in the normal way by connecting to house coax. I would open a browser and get on the internet. I would pick a video on the internet. I would feed audio and composite video (the output of a scan converter) to an RF modulator set to output on channel 4. I would hook this coax back into house coax through use of some kind of coax coupler (maybe a splitter). I am asking for predictions whether this could work, or whether I risk damaging something if I tried it. Thanks for any help.
If you can get the signal out of the PC with a coax cable in regular video form that a TV will recognize, you can use a coax cable to connect to the TVs, but you will need a totally separate cable run for that, you can't just splice it into the cable you have now. So you will need 2 wiring setups for cable, one from the cable company, and another one that will go from your output.
Since you are not using the house coax for anything that should work. Your TVs have to have analog TV tuners in them though. The RF modulator will connect directly to the splitter. If the signal is not strong enough you may have to use a distribution amplifier instead of the splitter but you can try it first. The picture quality may be disappointing.