VGA to COAX - Having trouble

[NightOwls]

Hello everyone. I have been reading these forums for years and always found what I was looking for. However, today I found something I needed help with that I could not find the answer to. Here is the situation:

I have a client who needs to run video off his computer to 12 separate televisions with audio. This video feed is going into 12 separate rooms. Already wired in the walls are coax cables that he wants to continue to use (he will not even think about updating to HDMI).

Here is what I have penned/thought out:

Computer (VGA to Composite or HDMI cable / and / audio cable from audio-out) to Break-Out Box (with 12 outputs out). From the Break-Out Box we need 12 sets of composite cables. From each composite cable set to an RF Modulator to Coax to the final TV in each room.

My question... is this possible? And if so, where the heck do I find a 12 out port break out box?

[jagabo]

Look for video distribution amplifiers. You can probably use a passive splitter to split the output of your RF modulator and send it to a pair of amps like this: http://www.jr.com/boss-audio/pe/BS1_BVAM7/

Keep in mind the output of a VGA->composite scan converter will be standard definition.

[usually_quiet]

This would also only provide SD vide over coax, but as an alternative to a scan converter, would the client be willing to replace his current video card with one that has a TV-Out port? The TV-out would be connected to an RF modulator, and the RF modulator would be connected as jagabo suggested.

These are two exmples:
http://www.newegg.com/Product/Product.aspx?Item=N82E16814139041
http://www.newegg.com/Product/Product.aspx?Item=N82E16814130395

[nic2k4]

Then you need to inject the HTPC feed into the existing signal. Use a quality combiner, connect it before the coax is split to all the TVs, run a coax from the PC to the combiner. This drop amp would have been perfect and someone had 10 of them selling for $20, just a few weeks ago; it has 3 inputs and 8 outputs and can be daisy chained.

[NightOwls]

WOW! You guys are amazing! I have just opened all the links you made and going to do some research. Thank you all so very much! I hope this helps, I will write back once I figure something out.

Thank you again!