How do you reduce interference through a coax cable?

[GoingUp]

Here is the scoop... I have a 27" TV in my room and an ATI 9700 Pro All in Wonder. When I use a splitter to send cable tv to my computer to record, the signal looks like garbage on my TV and on my computer. If I just have it hooked up to the TV, and the other end of the cable is lying on the ground comin out of the splitter, everything looks fine.

Is there some material that I can use to help shield the cable better? I really would like to be able to record on my PC while watching TV on my 27" television...

 

[yoda291]

can't you use aluminum foil as shielding? /shrug

 

[Wingznut]

I'm not sure that it has to do with shielding, as much as it is a weak signal that doesn't like being split.

 

[conjur]

Can you elaborate on 'garbage'? Is it just snowy/grainy? Is there electrical interference?

 

[blackdogdeek]

Originally posted by: Wingznut
I'm not sure that it has to do with shielding, as much as it is a weak signal that doesn't like being split.

that's what i was thinking. you might need to pump up the signal with a signal amplifier. i think radio shack sells them. every time you split the signal, the weaker it gets, i believe.

 

[GoingUp]

The image just looks more grainy, and I get more snow and artifacts on the screen

 

[loup garou]

Originally posted by: blackdogdeek

Originally posted by: Wingznut
I'm not sure that it has to do with shielding, as much as it is a weak signal that doesn't like being split.

that's what i was thinking. you might need to pump up the signal with a signal amplifier. i think radio shack sells them. every time you split the signal, the weaker it gets, i believe.

Signal amp

 

[GoingUp]

So would I put that before or after the splitter?

 

[Fausto]

Originally posted by: werk

Originally posted by: blackdogdeek

Originally posted by: Wingznut
I'm not sure that it has to do with shielding, as much as it is a weak signal that doesn't like being split.

that's what i was thinking. you might need to pump up the signal with a signal amplifier. i think radio shack sells them. every time you split the signal, the weaker it gets, i believe.

Signal amp

Would this help with a regular cable signal as well? Mine is split once (for cable internet) and my TV picture is slightly grainy. Nothing horrible, but if I can clean it up for $30 it would be worth it.

 

[loup garou]

I'm no expert, but I'd imagine that in your case Gobadgrs, I'd put it before the split (since you have grainy picture on both), and in your case Fausto, after the split (I don't know what it would do to your filter/cable modem and wouldn't want to find out). I think the RS brand ones are hit or miss though, my roomate had one and it worked great, but my boss has one and it did nothing or made the picture worse. RS has a pretty liberal return policy, so I'd give it a shot and return it if it doesn't work.

 

[conjur]

The RS amps are suck. I'd look around for something by Channel Master or Wineguard. I had a RS pre-amp on my antenna setup and the interference it introduced was awful. The CM I got was much better.

Also, what type of cable are you running and for what lengths? RG59 isn't the best, esp. if you have longer runs. And, look for a low-loss splitter, too. Some can be bought that are only -3db. Yours is probably much worse...maybe -7.5db or worse?

 

[Dizway]

Use a better splitter like Monster and RG11 cables. If that doesn't help, try the Motorolla AMP booster... definitely solved my problem of too many TVs.

 

[loup garou]

Originally posted by: conjur
The RS amps are suck. I'd look around for something by Channel Master or Wineguard. I had a RS pre-amp on my antenna setup and the interference it introduced was awful. The CM I got was much better.

Also, what type of cable are you running and for what lengths? RG59 isn't the best, esp. if you have longer runs. And, look for a low-loss splitter, too. Some can be bought that are only -3db. Yours is probably much worse...maybe -7.5db or worse?

Good to see someone who knows what they are talking about....like I said I'm no expert.

 

[conjur]

heh...I'm no expert either. Just going off my experience in setting up an antenna array on my roof last year in the hope of picking up DTV signals from >70 miles away. I learned a lot about cables/amps/RF signal strength/interference/etc. But have much more to go!

Also, if the signal amp fails or doesn't do as well as you'd hoped, look to the PC in terms of reducing RF. Maybe replace the power supply, put it on a UPS, stop o/c if you are o/c.

 

[woowoo]

RG-11 is overkill
Go with RG-6
You may want to try a DC-Blocker on the computer side.
Most "cable" problems are in the grounding.
(Bad return path)
You could try a unity gain amp on the computer side
Reading your post it seems that you have plenty of signal
The computer is loading it down
Need----Isolation......

 

[Sepen]

Originally posted by: conjur
The RS amps are suck. I'd look around for something by Channel Master or Wineguard. I had a RS pre-amp on my antenna setup and the interference it introduced was awful. The CM I got was much better.

Also, what type of cable are you running and for what lengths? RG59 isn't the best, esp. if you have longer runs. And, look for a low-loss splitter, too. Some can be bought that are only -3db. Yours is probably much worse...maybe -7.5db or worse?

Any recommedations for a store to purchase either one? I have the same problem. Thanks.

 

[conjur]

Originally posted by: Sepen

Originally posted by: conjur
The RS amps are suck. I'd look around for something by Channel Master or Wineguard. I had a RS pre-amp on my antenna setup and the interference it introduced was awful. The CM I got was much better.

Also, what type of cable are you running and for what lengths? RG59 isn't the best, esp. if you have longer runs. And, look for a low-loss splitter, too. Some can be bought that are only -3db. Yours is probably much worse...maybe -7.5db or worse?

Any recommedations for a store to purchase either one? I have the same problem. Thanks.

Stark Electronic

About 2/3 down the page.

 

[GoingUp]

Thanks for all the input! I will give it a shot!

 

[Sepen]

Originally posted by: conjur

Originally posted by: Sepen

Originally posted by: conjur
The RS amps are suck. I'd look around for something by Channel Master or Wineguard. I had a RS pre-amp on my antenna setup and the interference it introduced was awful. The CM I got was much better.

Also, what type of cable are you running and for what lengths? RG59 isn't the best, esp. if you have longer runs. And, look for a low-loss splitter, too. Some can be bought that are only -3db. Yours is probably much worse...maybe -7.5db or worse?

Any recommedations for a store to purchase either one? I have the same problem. Thanks.

Stark Electronic

About 2/3 down the page.

Before I purchased the CM I went out and bought some of the low loss splitters and hooked them up today. OMG, what a difference. I no longer have to buy the CM, thanks!

 

[conjur]

Originally posted by: Sepen

Before I purchased the CM I went out and bought some of the low loss splitters and hooked them up today. OMG, what a difference. I no longer have to buy the CM, thanks!

Good deal.

That's the best place to start. Get as much of the original signal thru as possible. Adding an amp otherwise amplifies noise as much as actual signal and the old adage of garbage in/garbage out....

 

[Sundog]

I had this exact problem, and as others have advised.....get a top quality splitter. Those Radio Shack models are crap.