I have kind of figured out how to use Jaadu VNC on my computer/iPhone, and now want to use it to view my stored media on my HTPC via my homes existing coax.

What is the best way to output to a coax, so I can backfeed to the rest of the house, on channel 3?
If it matters, I also will be connected via DVI-HDMI to my HDTV
Thanks in advance

If you have a base-band composite output from your htpc (yellow RCA Video), then you need an R.F. modulator.

You don't want to feedback into Channel 3 though if you have basic cable running. It will interfere with the existing channel 3. You want to use a channel that isn't otherwise used.

Therefore, you need a "frequency agile" R.F. modulator. These are available from many companies including Channel Master, Aspen, and many others. It will cost about $100 for 1 channel, $200 for 3 channels.

The result will be low definition quality, but available to all T.V.'s connected to the cable system.

My video card only outputs dvi, and all of the tv's are CRT, so I'm not too concerned with picture quality. To be honest, cost is the biggest factor (cheap). Is there any USB type coax output devices, or will it have to be a new video card? Do they make hdmi/coax output cards? Or would I have to go composite and add a rf modulator?

Have you looked at the old video game adapters? I think those used to take rca and then convert to coax!

or here you go http://sewelldirect.com/belkin-rf-modulator.asp

One other basic idea would be to use an ond VCR with input then just use the rf output to feed the house. sure its not elegant but hey vcrs can be had for like $5 :)

Or get a used media extender

I have 2 xbox's that I plan to use in the future to stream, but I have to climb into the attic to finish wiring the cat5, which I really don't want to do, and that would only solve 2 of the streaming tv's...
I'm hoping to find a card that outputs coax, or I guess I can get one that outputs composite, and get another rf modulator to get the signal to coax...
I'm guessing we will mainly use it for watching movies, but I wouldn't mind being able to surf the net on the tv's too....
I guess I should get into the attic, before the temps start hitting 30! :o

You should be able to get an old video card that outputs composite fairly cheaply. But I wouldn't count on surfing the net - it will be so blurry that the text will be almost unreadable unless it is a huge size. Video will look ok but text will be an issue.

Another issue to solve your problem, in an indirect way, is to get broadband over coax adapters. I got a set of 3 Motorola NIM-100 adapters on eBay for about US$80 six months ago. Unfortunately I haven't seen these very recently on eBay but keep your eyes open.

Also look for the Linksys Media adapters that have just been discontinued - they do work on wifi networks. You will need Vista HP or better or Win7 (which is free for the next year or so) installed on your PC.