Your question does not make a lot of sense and I think you need to at least clarify here what you are wanting to do, or you are at risk of getting nonsense responses, as you got from Robert below.

The coaxial connection on the back of a TV is the RF antenna input. It is a modulated signal that has to go to the TV's ATSC tuner first to be demodulated.

>Is there a cheap adapter/converter which will convert from coax to component audio/video or VGA video and RCA (red/white) audio<

If you really want to go from an antenna input to component video, then you need to buy a tuner, such as this:

http://www.amazon.com/HUMAX-Digital-ATSC…

Now, I do have to warn you that I do not know for certain what AV outputs this device supports, I would assume it to be component video and possibly HDMI, but that it just a guess.

Robert is giving you information on this type of cable:

http://en.wikipedia.org/wiki/S/PDIF

which I see no indication that you are asking about from your post.

There's probably a good answer for you somewhere, but it won't be forthcoming without some more information. Is this for a commercial operations of some sort? What exactly is the source of your video signal? (Satellite or cable TV account, disc player and distribution system, etc.). What type of coaxial cable is used to distribute the signal to the monitors? What is the make and model of the monitors?

Update your question with that kind of detail for the best answer.

If the coax is carrying video from an antenna (ATSC), then you could use one of the DTV converter boxes, but the result would only be in SD. Most of the boxes have composite video and audio outputs (not component).

If the video is from a cable provider, then you need a cable box from them. Another alternative, if you're willing to hook up a PC to the monitor, is to use one of the HD HomeRun units from SiliconDust. These are networked ATSC/QAM tuners. They have both single and dual tuner units for about $80 and $130, respectively.

http://www.ramelectronics.net/audio-vide…

There's probably a good answer for you somewhere, but it won't be forthcoming without some more information. Is this for a commercial operations of some sort? What exactly is the source of your video signal? (Satellite or cable TV account, disc player and distribution system, etc.). What type of coaxial cable is used to distribute the signal to the monitors? What is the make and model of the monitors?

Update your question with that kind of detail for the best answer.

http://www.ramelectronics.net/audio-vide…

Your question does not make a lot of sense and I think you need to at least clarify here what you are wanting to do, or you are at risk of getting nonsense responses, as you got from Robert below.

The coaxial connection on the back of a TV is the RF antenna input. It is a modulated signal that has to go to the TV's ATSC tuner first to be demodulated.

>Is there a cheap adapter/converter which will convert from coax to component audio/video or VGA video and RCA (red/white) audio<

If you really want to go from an antenna input to component video, then you need to buy a tuner, such as this:

http://www.amazon.com/HUMAX-Digital-ATSC…

Now, I do have to warn you that I do not know for certain what AV outputs this device supports, I would assume it to be component video and possibly HDMI, but that it just a guess.

Robert is giving you information on this type of cable:

http://en.wikipedia.org/wiki/S/PDIF

which I see no indication that you are asking about from your post.

If the coax is carrying video from an antenna (ATSC), then you could use one of the DTV converter boxes, but the result would only be in SD. Most of the boxes have composite video and audio outputs (not component).

If the video is from a cable provider, then you need a cable box from them. Another alternative, if you're willing to hook up a PC to the monitor, is to use one of the HD HomeRun units from SiliconDust. These are networked ATSC/QAM tuners. They have both single and dual tuner units for about $80 and $130, respectively.