Best Cabling/hardware to boost signal?

[Bel]

Hey, I've just started playing around with my tv card to do some capturing. Works great with the cable signal that I have in my computer room, but I'm trying to get a sattelite signal from the room next door, approximately 50 feet. I have a long RCA cable with one connector to a smaller cable. As you can imagine, I get quite a bit of noise and interference which mainly manifests as a couple of lines which scroll upwards.

My question is what are the best methods of getting a clear signal to my capture card? A signal booster? I'd imagine getting a longer RCA cable without a connector will help a bit, but I still think there will be some noise due to the length of the cord. If anyone has a good setup and equipment they like, I'd love to hear about it. Thanks.

[Anonymous65]

You basically have two options, go RF or composite. It sounds like you're going compoiste video at the moment, and you have a ground loop problem (2 noise bars slowly moving over the picture). Try to lift ground at one end might help to stop the ground loop. Either way, you have to isolatre the ground an one end to remove the ground loop. Or, you can use the RF out and the tuner on the capture card. This will not five you the same quality video, but if you're capturing VCD, I don't you will see much difference. Also, using RF there should be no ground loop problem.

[Mirror_Image]

I'd be interested to see how well this thing works 50 or 100 feet away:

http://www.s-video.com/svideobalun1.html

[Bel]

Thanks for the replies. That CAT-5 solution looks kinda cool, but I'd rather not dump $70 odd bucks into the solution. Although, if all else fails I will probably give it a shot.

Skittelsen, you nailed the ground loop problem on the head me thinks. That's exactly what it looks like. What you failed to mention, and I in my ultimate ignorance do not know, is what do I do to cure a ground loop problem? <crosses fingers praying for an easy solution>

Also, ultimately (at least for the good stuff) planning to capture and burn to dvd in mpeg2 so the best quality I can get the better. Although now that you mention it, I do remember the last time I did this and didn't run into this problem, I was using coax.

[Riccardom]

I made a 10 meters composite cable with RG58 video cable and two gold plated RCA connectors.
The connectors were quite cheap, I found them in electronic store, compared to the high-fidelity version.
It works very well for me, without noise, compared to a 1.5 meter already-made cable.

Hope it helps
Riccardom

[Bel]

Well, that ground loop thing is definitely the problem. I did some research on it, and it turns out thats what I get for buying a house with crappy electricity. I did manage to solve it, so thanks skilttlesen I never wound have been able to if I didn't know what the hell was causing it.

I had to take the plugs of my tv and sattelite out of the grounded power strip, and plug them into a non grounded outlet. I figured that the grounding differential (whatever the heck that means) between the plug my computer was plugged into and the one that my tv was plugged into was causing the interference. I switched to RF for the video and still using composite for the audio as the tuner in my cheapo capture card is only a mono tuner. The wierd thing is when I plugged the coax directly into my sattelite, the ground loop noise appeared on my TV. Instead, I ran the cable through my VCR and now have a clear signal on both

Thanks again Skittelsen

[BJ_M]

all you need is a passive hum suppressor transformer on your cable lines between the two areas ... the shield on a video should never be lifted - though on a balanced audio line this is a proper thing to do.

a good quality composite cable can be run 100'+ and the same with very high quality s-video cables (where the y and c are carried on seperate cables).

here are some sources for the transformers: http://www.milestek.com/videohum.htm
http://www.allenavionics.com/VideoHumEliminator/VideoHumEliminators.htm
http://www.tectonrd.demon.co.uk/humbug.html
http://www.vac-brick.com/

there are a lot more and also active devices ...

[BJ_M]

http://www.epanorama.net/documents/groundloop/video_isolation.html

very good article on it all ..

also home equipment is only 2 prong into your mains for the most part ...

when you have potential diff through out your system and you have a loose neutral and/or other problems -- you could be setting yourself up for a nasty shock if grounding is not properly done on a distrubuted system.

[Bel]

Well, I did a bit more experimenting... I'm fairly happy with the quality of the video at this point, through the coax. The problem I'm having now is with my audio. I'm getting a lot of noise which I assume is part of this whole ground loop thing.

Now, ALL of my audio equipment is only 2 pronged. As far as I understand electricity (which is next to nothing) none of them are protected by grounding, even if they are plugged into a three pronged grounded power strip. Correct? Believe me, I don't want to kill myself here. As I understand this whole ground loop thing, it's only caused when there are two different grounds with different differentials (or whatever). So, I assumed that if I removed the power strip from the equation than the only grounding in the whole setup would be from the computer, which everything attached to it is three pronged and grounded. Therefore, no loop right? I did have the audio signal clear on the computer end during one instance, but that was when the interference was coming from the TV setup.

I'm still playing with it, but any ideas are appreciated. Although those video noise reducers seem cool, I definitely don't want to spend that much money to get rid of this noise. It would be cheaper to just buy the stereo version of the tv card and use the coax for it all. Oh wellz, back to pullin cables...

[Anonymous65]

Good to hear you found a solution to stop the ground loop.

Lifting the ground is fine, it is actually better than not lifting it if there are different ground levels. Different grounds can give some nasty and strange problems. All electronics today have an isolated (switch mode) power supply, so a floating ground, or a ground connecting the devices together is fine. As long as one end is grounded, you're fine. One-end grounding is often used in professional audio shielding and lightning protection.