Cable splitter interfering with connection?

[Ruahrc]

We have only one cable outlet downstairs in our house, and we want to drive both a cable modem and a TV at the same time. So we got a cable splitter and put one output into the cable modem and the other output into the TV.

So recently we have been having connection issues, and we can't figure out the source of the problem. Sometimes it seems like removing the splitter and going straight to the cable modem fixes it, but sometimes it doesn't.

Could it be that having the splitter is making the signal too week or too noisy for a reliable connection, or is all of that bogus? Do we need a special splitter that is capable of handling data streams? (The one we use now is just a standard RS gold VHF/UHF splitter)

What do you guys think? Any ideas? If we called up Comcast (Comcrap) and told them we were having problems would they (of course) pinpoint it on the splitter and tell us to take it out, despite the fact that we still have problems even if the splitter is not even in the picture?

Ruahrc

[RobRich]

It could be the splitter, interference, and/or singal quality. What type of coax are you running, and how far is the connection being ran?

[Paluccie]

you can also try, a higher frequency splitter. Lowes/Home Depot I know sells one. The one that would work would be any that range up to 2ghz. It may or may not work. RadioShack also sells one but they are way over priced.

[Atomic Rooster]

Sounds more like the problem is on their end. We use a splitter that was installed by the Comcast cable tech dude with a 10ft cable to our modem with no problems. You might want to contact Comcast, and/or run the Comcast support software.

[RobRich]

I has been a long time since purchasing splitters at RS, but I believe the gold series models offer extended frequency coverage up to 1GHz. If so, that is plenty for cable Internet.

BTW, this may sound stupid, but have you tightened all connections with a pair of pliers? I have fixed plenty of cable problems for other people caused by nothing more than a lose connector.

[Atomic Rooster]

Good idea Rob. Forgot all about that one.

[Siliconjunkie]

Also, make sure that you have good quality ends on the cable, the little crimp on one are terrible.

TW here installs an "unbalanced" splitter that sends 50% to the modem, 25% to one TV and 25% to the other TV. Mine is in my attic, TV is downstairs, modem is right next to the splitter. Probably 150-200 feet from the tap to the TV, 100-150 to the modem with no problems.

[Jeordiewhite]

Hmm, a guy I knew was helping me with my cable internet and said to avoid the splitters used for sattelite equipment. I.e. the ones above 5-1000Mhz range, the 5-1000Mhz is what you want tho. Anything above that will have problems with your cable internet. The guy who installed my cable internet from comcast told me the same thing, since I had a spare splitter around with a higher signal range that was sitting around from my friend leaving it. He said dont use ones like this for cable internet and got me a new splitter from comcast.
If a problem isn't from the cable, like if you had all rg6 and splitter was good, you can call comcast to come out and up the signal going to the house so it provides enough signal strength for each componant in your house.

[Ruahrc]

We have I believe a 25foot cable running from the wall to the splitter, and then about a 2-3ft cable running into the modem from the splitter. The cable going from the splitter to the TV is a 25-ft cable.

All the coax used is pretty thick and high quality- at least it seems like it is. I will try the pliers thing too, I usually just hand-tighten them all the way down. One last question- the splitter has this grounding attachment on it- would it help any to use that? I presume that just running a wire between it and say a metal computer chassis would work? I don't have a water pipe or anything fancy like that nearby where the splitter is.

Maybe I should just call Comcast and have them boost the signal strength, is that an easy thing to do/something that requires them to come out on site?

Ruahrc

[jdahl1979]

How many splices are in your house. Your TV's can stand a 7.5db loss and distribute say 3.5db or less of a loss if possible by the splitter to your modem. I think you need a different setup for your distributing splitter at the service outside or a new one all together.

[pphalan]

Check your cable junction box mounted on the house, there will be a barrel conector with a ground for static. You may need to replace it and put new ends on the cable, now if the signal is sharp and clear on all channels of your TV set then its not your cable connections.

[excuzzzeme]

Have found that splitting closer to the source ( where it comes into the house), and then running cable to the modem is far superior with less line-loss than with any other method. (Probably not what you want to hear). A larger multi-port splitter has less loss than using smaller multiple splitters. Learned this from some network techs that specialize in cable runs.

[Siliconjunkie]

The ground is for static more than anything just like pphalan said. Unless there is alot of static on the line it wont change anything and also like he said it should be grounded where it enters the house.

as for "some network techs that specialize in cable runs" not sure what to make of that. Sounds like an electrician that specializes in cable TV, the only thing the two have in common is that they use wires, beyond that it is apples and fish.

A larger multi-port splitter has less loss than using smaller multiple splitters.

You still have X amount of signal to start with and split it Y number of times, so you get X/Y signal, unless it is an unbalanced splitter. The difference is that if you put a splitter off a splitter the signal going into the second splitter is lower so the output will obviously be lower. You have to figure out what works best for your situation.

It may be best to put a 2 way splitter with one leg going to the modem and the other going to another splitter to feed your TVs. TVs are generally more tolerant of low signals than the modem. Doing this lets you send the max possible to your modem and enough to work to your TV.

[Sweeper]

Hmmm.... TW has mine split outside the house in the cable box which they lock. The cable line and then the rest of the house (each room: 4 + kitchen) are run around the house into a junction on each wall in each room.

[electric]

does the existing cable to your downstairs room exit from the wall [cable]or
are you using a wall outlet;if you are take a look at that outlet
for loose connection inside the wall outlet and the female connector for
wear .as mention loose connections will cause grief


fyi most shielded cables are only grounded at the source

[pphalan]

.
So recently we have been having connection issues, and we can't figure out the source of the problem. Sometimes it seems like removing the splitter and going straight to the cable modem fixes it, but sometimes it doesn't.

What do you guys think? Any ideas? If we called up Comcast (Comcrap) and told them we were having problems would they (of course) pinpoint it on the splitter and tell us to take it out, despite the fact that we still have problems even if the splitter is not even in the picture?

Ruahrc

Starting with your original description the splitter is not your problem, If your not having any problems with any channels on your TV that demostrates your line is handling a wide band of frequencies, So I would look at comcast or the modem. I get paid an obsene amount of money to troubleshoot hardware.

[The Hound]

I would never use a splitter for a cable modem. It just opens you to the unwanted like EMI and RFI, issues usually only associated with your TV and radio because of reduced sheilding of the signal. If you must use a splitter, yours is crap. A VHF/UHF splitter doesn't even cover up to 900 MHZ, which after that, they make no claim about signal quality, even for your less vulnerable TV. Some cable networks go slightly above 2 ghz or more, so an expensive splitter that claims insane frequencies like 5ghz is a very reasonable idea. Check your saignal with it installed and accept nothing below 35db/mv, at very least to make up for sheild loss. Your modem should have a login IP address URL, if it's a modem/router it's usually 192.168.100.1 or 192.168.0.1. That is the default for most home networks and the login will stay the same even if you change your ip or use a dynamic one. While you're in there, if your modem is a router, the firewall may be causing you connection issues. Check the required ports for all your applications http://www.portforwarding.com has many common ports for applications and is a useful resource. And for speeds sake, ditch the VHF/UHF splitter or you may as well have dial-up as it is probably killing your speed. Peace!!

[pphalan]

Hound he has the same problem WITHOUT the splitter.

[The Hound]

Maybe comcast does't use such high frequencies, dude. I know Roadrunner in some areas does. A higher frequency never hurts, as I have one for my plasma Tvs to handle the HD signal, which almost amounts to one-way broadband signal just for TV. My signal was always fine for digital cable, but both my HDTV service and cable internet were troublesome until they installed coax that handled 5ghz because the cable internet changed their frequency from starting at 800Mhz to starting at about 2. Bottom line be safe and get a higher frequency splitter. It does not affect lower frequencies and may actually improve them because better shielding is required on these high ones, And as far as the preoblem w/o the splitter goes, as I just saw from pphlan, do check for any gateway firewalls, as i said, and configure accordingly. Some of these gateway firewalls are touchy and will kill your whole connection if they are made to block too much(I had that problem the first day with cable). Oh and one last thought, check for spyware and trojans as they may try to communicate on ports your firewall isn't allowing.