S-Video TV Out to Coax w/Signal Amplifier. Best quality way?

[SVCD4Ever]

Hi there everyone,
I am planning on getting a Sigma RealMagic card (Xcard most likely) and I want to use the S-Video out and convert it to a Coax signal.

The coax (RG6 cable) is what I want to output to as my house is wired for it and will be like a home tv network of my htpc setup of video/tv tuner/satellite tuner.

I will probably buy a Monster Cable ConnectAlll 200 S-Video RF Modulator which has svideo in. Link: http://www.monstercable.com/productPage.asp?pin=1915
This seems like a good option to get S-Video to Coax, the other I know of is using S-video to Composite to VCR then out through the RF from the VCR. But I would think this method will result in better quality. The Monster Cable RF also has "Video input booster provides brighter picture for low output video components"

But I also plan to get a coax signal amplifier as it is (15db to 35db increase, some even 50db). Perhaps something like the Motorola Signal Booster: http://broadband.motorola.com/consumers/products/signal_booster/
But I was not sure technically what frequency range a tvout in such a way would be. My guess is it would be low. (5mhz-500mhz). Would anyone know?

Also would this be "Stereo" being outputed through the coax if the audio is inputed with a headphone to composite stereo in. Not sure if the RF Modulator will retain stereo even though it has Right and Left Audio inputs.

This is what I have thought up....
But there may be a easier/better quality way of getting TV out to coax. Any thoughts?

Also someone had once mentioned DVI to TV Out... is that possible and would that be of better quality then S-Video out on a Realmagic card?

I am sure these questions will help clear up some gray areas of "TV Out" optimum quality issues that others may have also.

Thanks for reading my post.
And thank you for any feedback. It is greatly appreciated.

[Suntan]

It will work, but the overall quality will be quite low. As for pumping the signal up with a 50db line amp, I would not do that. The signal coming out of the modulator should be strong enough so it will only amplify the noise at best, and could blow out the tuner in your TV. Unless you are looking to send the signal down the block to your friends house you will most likely not need any amp.

-Suntan

[Ste]

If you can get ahold of some sort of ATSC Modulator (really expensive and only used in the broadcast industry) and then use DTV tuners to grab the signal for your TVs scattered around the house. This is the only way to get a better picture than what you suggested, but it is quite unreasonable.

Also someone had once mentioned DVI to TV Out... is that possible and would that be of better quality then S-Video out on a Realmagic card?

Since your final product in both cases is going to be Coax, then your source (DVI or S-video) isn't going to make a difference.

I have that motorola signal booster and it doesn't do much. It's mainly used for cable modem users because normal cable amplifiers don't have a return DC pass. And plus, that thing only amplifies cable channels and you're sending a CH 3 or 4 VHF signal. You'd only want to be using a distribution amp with this project.

Also, RF signals can carry stereo so I don't know why that Monster Cable one cannot do it. Try to find one that is capable of stereo if sound is really important to you.

[Suntan]

Another possibility, if you happen to have CAT5 (or even CAT3 phone wire) going to all the places you want to watch TV and a receiver that can decode digital PCM stereo at every location, would be to send the composite signal (without modulating) through the RG6 and run the PCM stereo over a twisted pair of the CAT5/CAT3 (if you also have your phone line running through these wires then don't use the blue and green wires use any of the others) You alos need to have a soundcard that has a spdif out (most newer cards do.)

This will give much better results than RF and you can even pass 5.1 Dolby Digital along this way. Although it only makes sense if you already have the equiptment throughout the house.

Let me know if you want more info.

-Suntan

[lgh529]

This seems like a good option to get S-Video to Coax, the other I know of is using S-video to Composite to VCR then out through the RF from the VCR. But I would think this method will result in better quality.

It makes no difference in quality, since you end up with the same signal.

But I also plan to get a coax signal amplifier as it is (15db to 35db increase, some even 50db).

The only time you need a signal amplifier, actually its really a distribution amplifier, is when you have excessive signal loss. This happens with long cable runs and splitting the signal. For example, if you run an RF signal through a 2-way splitter, the signal loss on the output is 3 dB less, a 4 way is a 5dB decrease in signal, etc. RG6 cable also looses about 3dB of signal per 100 feet in the VHS band (more loss for higher frequency). So the only time you would need a 50dB Amplifier is if you splitting the signal to 25 different TV's and running over a 1000 feet of cable.

Keep in mind that a signal amplifier has absolutely nothing to do with the quality of signal. It only compensates for loss.

Not sure if the RF Modulator will retain stereo even though it has Right and Left Audio inputs.

You need a stereo modulator for this to happen. Not all modulators are stereo, even if they have right and left inputs.

Suntans CAT5 idea is better than coax for you. If you got creative, you could probably make an S-Video adapter to CAT5. S-Video cable is just a pair of coax cables molded into one, and the bandwidth for each is only 6MHz. CAT5e cable is rated at 550MHz and the common mode rejection in the twisting will probably isolate the two signals sufficient for a home application.

Maybe I'll have to try that myself.

[Suntan]

Well I tried passing the video signal along the CAT5 as well and it does work, but in the end you will find it somewhat unacceptable. If you only pass the video signal over the CAT5 it is somewhat acceptable (constant diagnal "ghosting") but if you send the PCM audio on another twisted pair you get messy ghosting that swims around the screen. Although you can get Baluns spicifically for this purpose, Google for them I believe they are about $80 for a pair that will send Svideo and audio across unsheilded CAT5, but I never tried them as it was just easier for me to pull another run of RG6.

Somewhat related, over on the AVSforum I read about some guys haveing very good luck making long homebrew component/VGA cables from sheilded CAT5 cable...

-Suntan