Can hd signals run through coax?

Backstory: My mom gave me her old computer monitor (Samsung SyncMaster 2232BW), it is now my desktop monitor. I threw out my crt tv after getting the new monitor and bought a ATSC Tv tuner(Newegg.com - KWORLD PlusTV HD PCI 120 ATSC 120 PCI Interface - TV Tuners & Video Devices ) for my computer.


Currently: I watch all the same channels i could watch on my old tv through my monitor with the same quality. But, i want MORE, i want to watch hd tv, so i tryed to make a hdtv antenna, that didn't work out for me, for some reason it isnt picking up any hd channels only sd. I have a 720p version of transformers which i forced 16:10 aspect ratio with vlc media player and it looked great.

Problem: i want hdtv but my tuner only has a coax input. However, i do have a vga to component cable with couplers, for some reason when i plug my 360 in with that vga to component cable it displays all green(something to do with RGB and YhPhRh, right?). Will the IO box do this? How can i watch hdtv through this monitor with my current setup(can i get a dvi to hdmi female adapter.)Btw, the native resolution for this 1680x1050.

One last thing: for christmas i was thinking of getting surround sound for this room assuming i get everything situated what are some suggestions for a decent set that doesnt cost too much.
Edit- These any good(http://www.amazon.com/Logitech-540-m...8080936&sr=1-4)
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yes you can get HD signals through coax. It's how they are delivered today. All your virgin signals come into the house via copper coax cable 50ohm. All your FTA signals from the aerial on freeview come down a 75ohm copper coaxial cable.
As for the rest I don't understand it.
Where is your HD signal coming from? If you are getting it DTA from the BBC then chances are you need to connect your tuner to the rooftop aerial.
If you are getting it from virgin have they switched you on to HD ( they'll want money for a box ) and have you got that signal going into a tuner?

 

so if i get a new io box, i can just run a coax cable into the back of it and a coax cable into the atsc tv tuner?

 

I'm not sure what it is you are exactly trying to do. You need to take the cable that is carrying the HD signal ( be it from Virgin or Free to air digital ) put on a plug that marries the signal in socket of your tuner and plug it in. Then you rescan. any channels you are able to get will show. Any you are not authorised to see won't.

edit. That's actually wrong. Forget about Virgin. It's a TV tuner and not a cable tuner I notice.

You can plug your roof aerial into it. Whatever you get is whatever BBC HD channels are transmitted right now. That's it. You can not turn all of your channels into HD by viewing them at a higher resolution if that's something you were thinking.

 

i mean since my "tv" has no component inputs, if i get an hd cablevision(io) box in my room and plug the coax they send me outside into the box(into the input) and then plug a coax(output) into the atsc tv tuner i have(opposed to hdmi or component.)

 

I don't think that the HD boxes work like that. I'm sure you can loop the digital signal out to anither decoder but the inly way of sending the signal out of most boxes is scart or s-video.
You don't need a TV tuner for what you want to do. You need an HD box with an uncoming HD signal. You need either S-Video out or HDMI out going to a VIVO ( video in video out ) graphics capture card that is HD compliant. Then you can capture your TV signal on the PC and view it.

The only thing you can do with your tuner is plug the roof antenna into it and get whatever it receives. You can not put a cable TV signal to it because it's not a CAM decoder and you can't put an output from a box because all that will do id loop the RF feed from the antenna to your card which is just the dame as plugging it in directly.

Digiboxes do not loop their video output from the RF out port.

 

i see, so... My monitor has vga in and dvi in, hopefully the cablebox has dvi or vga out, if not, i can get a dvi to hdmi coupler (http://www.monoprice.com/products/product.asp?c_id=104&cp_id=10419&cs_id=1041902&p_id=2029&seq=1&format=1#largeimage) then hdmi cable connecting the dvi/hdmi input to the hdmi output on the box?