Cable tv "networking"

[112]

I'm not sure what you call splitting your cable service between several tv's in your home. I wanted to split my cable so that I can get cable tv in multiple tv's in my house. I checked and saw that i have a 2 way splitter installed. One running to my cable tv, and the other running to my cable modem. If i wanted to add an additional tv i supposed i would have to purchase a 3 way splitter. I also noticed that the coaxial cable running towards my house has a "filter" or metal device that connects 2 cables. I was wondering what that was. Its on both my cable tv and cable modem cable. If i wanted to add an additional tv, what supplies would i need to purchase? Would i just need a 3 way splitter and coaxial cable? Or would i also need to get that "filter?" Are generic brands good enough, or should i get high quality (more expensive) items to get better, cleaner reception? Thanks a lot!

 

[Utterman]

The filter blocks premium channels from being accessed. You do not need to worry about that. I suggest that you leave the cable going from the splitter to the cable modem alone so it has the best signal. The other cable going to the TV is the one you can split off of. Get a multiport splitter for the number of TVs you want to hook up.

You can either buy cable that is premade or you can purchase a crimper and stripper to make you own cable. IMO, if you don't feel like buying the equipment to make you own cable or don't know how to make the cable, the premade would be a lot better for you.

First take a cable and run it from the original splitter to the input of the new one. Then run cable from the new splitter to the TVs and make sure the connections are nice and tight. If you have any problems with the picture, then I suggest going to radioshack for advice on an amp. to make the cable signal stronger.

 

[AnMig]

just use a splitter from radio shack.

If you start to have signal degradation from to many splitters. Get a signal amplifier also at radio shack.
I was ther last week and they have a signal amplifier with a adjustable gain for $29 but it rang up $10
since it was in clearance.

They say you need a signal booster for every 100 feet of extension

good luck.

 

[Ark]

Originally posted by: AnMig
... Get a signal amplifier also at radio shack

Make sure you get bi-directional amp, if you have cable modem.

 

[Texun]

The cylindrical devices you see are filters of some type. They may be used for blocking pay stations but those are usually placed at the pole or backyard ped. If you see them in your house they are probably being used to filter unwanted noise from the active devices in your home, like the TV, VCR, cable boxes etc. If this is the case, then I suggest that you leave them alone since they would be there to keep either the forward or return signals clean. Noise generates packet loss and can lead to dropped connections causing your modem to cycle.

I would also suggest that you leave the coax feeding the cable modem as-is. Additional splitting before the modem will necessitate a higher transmit level from the modem, and the modem can only transmit so high before it gives up and starts cycling again in an attempt to lock in at a lower power level.

Use quality hardware if you want to do this on your own. Poorly shielded hardware will lead to ingress, wavy lines, and noise being generated back in to the same line that feeds the forward and return of your cable modem.

Or, you could call the cable company and let them do it. The fee where I live is $20 and they take care of everything, including future repairs, as long as I don't need cabled fished inside a wall.

Do not get an amp unless you are 100% sure you need one. They can cause more harm than good when they are not needed, or when they are installed at the wrong point. Never use an amp inside at the modem or TV. It will only amp what it sees..... which at that point will be noise. The place to amp the signal is before it degrades to a point where there is a need.

 

[Trevelyan]

Originally posted by: texun
The cylindrical devices you see are filters of some type. They may be used for blocking pay stations but those are usually placed at the pole or backyard ped. If you see them in your house they are probably being used to filter unwanted noise from the active devices in your home, like the TV, VCR, cable boxes etc. If this is the case, then I suggest that you leave them alone since they would be there to keep either the forward or return signals clean. Noise generates packet loss and can lead to dropped connections causing your modem to cycle. I would also suggest that you leave the coax feeding the cable modem as-is. Additional splitting before the modem will necessitate a higher transmit level from the modem, and the modem can only transmit so high before it gives up and starts cycling again in an attempt to lock in at a lower power level. Use quality hardware if you want to do this on your own. Poorly shielded hardware will lead to ingress, wavy lines, and noise being generated back in to the same line that feeds the forward and return of your cable modem. Or, you could call the cable company and let them do it. The fee where I live is $20 and they take care of everything, including future repairs, as long as I don't need cabled fished inside a wall. Do not get an amp unless you are 100% sure you need one. They can cause more harm than good when they are not needed, or when they are installed at the wrong point. Never use an amp inside at the modem or TV. It will only amp what it sees..... which at that point will be noise. The place to amp the signal is before it degrades to a point where there is a need.

I was wondering about this myself.... I have a 3way splitter in my wall, which sends signal to three different TVs.... if I buy an amp, should I hook it up right before the cable splits into three?

 

[Barnaby W. Füi]

i talked to a cable guy a bit about cabling, what he told me is that most of the signal loss is from bad/low quality connectors, and sharp bends in the cable.

i'd say, if you get a splitter, dont get a POS, dont use POS cable, and put the cable modem as close to where the connection comes into the house as possible. the filter thingies i believe are to filter noise from the cable modem, and i believe should be put on the split cables that go to your tv's, although i could have that backwards, all of my cable is buried behind things and i'm too lazy to dig it up

 

[Texun]

Originally posted by: Trevelyan

I was wondering about this myself.... I have a 3way splitter in my wall, which sends signal to three different TVs.... if I buy an amp, should I hook it up right before the cable splits into three?

You got it.

Add an amp under these conditions:

1. The picture quality is poor, especially on the higher channels after you add the splitter and more coax.

2. Always add the amp before the split... have it feeding the input of the splitter. The three way will cut the signal by 7dBmv. For every 3dB the power level is cut in half which. Adding the amp after the power loss gives the amp more noise to amplify. Your levels will be strong again but the quality of that signal will be dirty.

Less is often a good thing in this case so do not let anyone sucker you into getting a big amp. A high quality amp somewhere in the range of 8-12dB should be more than enough. A gain of more than 10-12dB could be difficult to manage depending on the signal level it is amplifying. Too much gain will cause cross mod, whereas the picture will be horrible and you have to start playing with attenuators on the front end and doing a lot of guesswork.

One more note: More signal does not always produce a better picture and will do nothing to improve modem speeds unless you have a problem of another sort, such as a S:N problem in which case the amp could trick the modem but it will not be the solution.

 

[Trevelyan]

Ok great! Thanks a lot!

 

[MedicBob]

Be carefull of adding an Amp to the line. I have been reading, but haven't seen for myself, that an bi-directional amp will add "noise" to the cable line, hence addin more interferance to everyone on your node.

Not positive myself, but a buddy that used to do line quality checks says the above is basically right.

 

[Texun]

Originally posted by: MedicBob
Be careful of adding an Amp to the line. I have been reading, but haven't seen for myself, that an bi-directional amp will add "noise" to the cable line, hence addin more interference to everyone on your node.

Not positive myself, but a buddy that used to do line quality checks says the above is basically right.

Yep. This can happen, but it is not specific to bi-directional amps only. Excessive noise from any active device can do this.

Fortunately, there is pretty good isolation at the line which helps keep impulse noise from entering the node. If not for the isolation many of us would not be reading this page right now. I have seen situations where noise coming from one house was significant enough that the cable company shut the customer off until the problem could be resolved. This isn't an every day thing, but it is not that unusual either.

Unless a person wants to experiment with some do-it-yourself cabling, it seems that the best method is to pay the $20 average fee and have the cable company supply the hardware and do it for you. Still.... there are those like me who would rather do things their own, way which is why I have a small fortune tied up in a stack of PC's with a current street value of a only few hundred dollars. Either way works as long as you get what you want in the end.

Adding cable and splitters is easy. Getting everything to work perfectly is another matter. Even cable techs often miss that one. All too often I hear someone refer to something that was professionally assembled and say, "It looks good so why won't it work?" I then ask how it looks on the inside, meaning performance wise, and usually get the old deer in the headlights response.

Get some quality parts (don't go for the gold plated crap... the only purpose that serves is to catch the buyer's attention) and go for it!
Have fun!