# Using splitters on coaxial cable



## svaic00 (Jul 2, 2012)

Hello, 

Have a question with regards to using splitters on coaxial cable. 

I live in Chicago suburbs, have comcast as my cable company. 

Currently I believe my setup has the cable coming into the house, going to a 2 way splitter, one line goes to my computer room (cable modem, router for wifi, etc.), the other line goes to another splitter that is a 5 way I believe. Those 5 runs then go to each of the different cable outlets in each of the different rooms. The installer said they did it this way, so as to have the internet and cable modem get a really strong signal, then the rest of the signal is split between the other TV spots.

1. Does that mean the computer room/wifi is getting 50% of the signal, and the other 5 TV's are getting 10% of the original signal? (Guessing there are a few db's lost with regards to the splitting?).

2. I am adding a TV in the basement, and may add another TV outlet by the bar for a smaller TV, so now I need a 7 way splitter (do they make that or do I need an 8 way)? 

3. If I need to get an 8-way, but say I only use 6 or 7 of those outputs, I've read somewhere that I should cap off those unused terminals, is that true? What kind of cap is needed?

4. Should I keep the setup that I have, cable in to a 2-way, one line to the computer room, other line to the 7 or 8 way splitter, and then those 7 or 8 runs to the TV's in each room? With an 8 way, that means each TV is only seeing like 6% of the original signal. Will this be OK with the new TV in the basement being a 4K TV? What is the typical db level of the signal coming into a house, and what is typically needed for each TV? 

5. What kind of splitter should I get?

Thanks,
Steve


----------



## jimn (Nov 13, 2010)

The installer was smart. Splitting first for the cable modem is the way it should be done. As far as the TVs go, the fewer the splitters the better. The splitter is rated on each output with the signal drop. If you need that many drops you will likely need a signal distribution amplifier to properly support that number of TVs. Best Buy must love you  .


----------



## ddawg16 (Aug 15, 2011)

A 2-way splitter will have about half power (3.5DB loss) at each output

A 5-way splitter.....oh boy....
One port on that 5-way will be 25% of the original signal (50% of the 50% from the 1st splitter)....the others? Way down there

I would suggest an amp. I have one that is bi-directional. In other words, it will also amplify the signal from the cable modem back to the cable


----------



## ktkelly (Apr 7, 2007)

svaic00 said:


> Hello,
> 
> Have a question with regards to using splitters on coaxial cable.
> 
> ...



The installer did it wrong.



> 1. Does that mean the computer room/wifi is getting 50% of the signal, and the other 5 TV's are getting 10% of the original signal? (Guessing there are a few db's lost with regards to the splitting?).
> 
> 2. I am adding a TV in the basement, and may add another TV outlet by the bar for a smaller TV, so now I need a 7 way splitter (do they make that or do I need an 8 way)?
> 
> ...





I'll answer each:

1. No, it isn't that simple a matter. There will typicallt be a 3.5 db loss on each port, so the loss could be about 50%, or it could be much more, as it depends on the signal strength at the demarc (outside location where it enters the house).

2. You need ONE 8 way splitter/amplifier.

3. You typically use a 75ohm cap on unused ports to prevent signal leakage, although it's not the end of the world if you don't.

4. Dump the current installation if possible.

5. http://www.amazon.com/gp/product/B0..._m=ATVPDKIKX0DER&pf_rd_r=1J26A2F2A95CSGCY0RTA


Now, you would install this splitter/amplifier outside, IN the demarc box or just inside the home near the coax entry point, using and extra piece of coax to feed the power to the amplifier if need be.

What you would have at that point is almost exactly the same signal strength at every coax drop. The only difference being that since each drop will be a different length, each will have a slightly different strength.

Coax typically has a 7db loss per 100 feet (using the worst case scenario, since it varies by frequency) that also has an effect.


There's more, but I don't want to overload you...:smile:


----------



## indigo (Dec 14, 2009)

http://www.amazon.com/gp/product/B0..._m=ATVPDKIKX0DER&pf_rd_r=1ZEYY5ZWZCM5R6Z88TQW

This is a better option for you as it provides a dedicated port for the modem connection and will allow for the moca communications across the boxes and has some spare outputs for you.


----------



## svaic00 (Jul 2, 2012)

ktkelly said:


> The installer did it wrong.
> 
> 
> 
> ...


I was slightly mistaken in our set up, there are 3 total splitters from the original set up, not 2. Cable comes into house to a 2 way, one line to comcast cable modem for phone and internet, other line goes to another 2 way splitter. One line goes to our family room (most watched tv currently), other line goes to a 4 way. That 4 way then goes to the 4 bedrooms. Right now I'm trying to add another line for the basement. So would need another 2 way or a larger splitter. I know it's bad too have numerous splitters, so I like the single 8 way splitter/amp you showed. 

With regards to the splitter amp you showed, I see there is an input and 8 output, the other port is a power port? You mentioned to use a spare piece of coax to power the amp if need be, where does that power come from if your using coaxial cable, where do I connect it to? With this 8 way, will the internet decrease in speed since the line going to the cable modem is 1/8th the original signal (plus a little bit from he amplifier)? Where before it was 1/2 the signal? Also, how do I know if they already installed an amplifier outside in the box? I thought I read somewhere you don't want to amplify and already amped signal?

What about the moca communication across boxes that indigo mentioned? Is that needed for the comcast x1 platform?
Thanks,
Steve


----------



## svaic00 (Jul 2, 2012)

indigo said:


> http://www.amazon.com/gp/product/B0..._m=ATVPDKIKX0DER&pf_rd_r=1ZEYY5ZWZCM5R6Z88TQW
> 
> This is a better option for you as it provides a dedicated port for the modem connection and will allow for the moca communications across the boxes and has some spare outputs for you.


Is this also an amplifier? With regards to the dedicated port for the modem connection, does a larger % of the signal go that way, and the rest is divided between the remaining ports? 

On this splitter, I see 11 ports, is that 1 input, 9 regular outputs, and 1 output for the dedicated modem connection? Or is it similar to my comment to ktkelly? Where one of the ports is for power? Where does that connect to then?

Thanks,
Steve


----------



## indigo (Dec 14, 2009)

Here's a link to the install guide for the PPC piece:

http://www.ppc-online.com/docs/MKTimages/upload/Installation-Guide-9-port-Generic-2.pdf

Yes, it has an amp. Yes, it needs external power supplied via coax. Yes, MoCA is absolutely needed for Comcast X1 service. 

The modem port is a passthrough which is helpful for the return signal and keep voice service functional if there's a loss of power to the amp. Incoming signal is then split and amplified to the additional 8 outputs.

As for whether they already installed an amp at your house -- it's highly doubtful. Given it's comcast you probably just have a single drop from a pole (or underground) and then the stack of splitters.


----------



## svaic00 (Jul 2, 2012)

indigo said:


> Here's a link to the install guide for the PPC piece:
> 
> http://www.ppc-online.com/docs/MKTimages/upload/Installation-Guide-9-port-Generic-2.pdf
> 
> ...


Thanks. With regards to some of the coax runs we have, there are two lines that go to bedrooms that have no tv's or cable boxes. The line just ends at the wall outlet in the bedroom. Should I cap the outlet in the wall with a 75 ohm cap in the bedroom, or should I actually detach those two lines from this splitter, and cap off those extra ports on the splitter? And then in time if/when we get a tv/cable box for that room, just reconnect the line(s) that are needed? OR is that not really much of an issue?

Thanks,
Steve


----------



## ktkelly (Apr 7, 2007)

svaic00 said:


> With regards to the splitter amp you showed, I see there is an input and 8 output, the other port is a power port? You mentioned to use a spare piece of coax to power the amp if need be, where does that power come from if your using coaxial cable, where do I connect it to? With this 8 way, will the internet decrease in speed since the line going to the cable modem is 1/8th the original signal (plus a little bit from he amplifier)? Where before it was 1/2 the signal? Also, how do I know if they already installed an amplifier outside in the box? I thought I read somewhere you don't want to amplify and already amped signal?
> 
> What about the moca communication across boxes that indigo mentioned? Is that needed for the comcast x1 platform?
> Thanks,
> Steve



Since this is an amp, all ports will have no loss. Basically what goes in will come out at each port (7.5db input is 7.5db output on all ports).

Since there is a passive return (two way signal passing), it will work with moca.


For power feed you simply use a piece of coax between the amp power input and wherever you find a place to plug in the power supply (the cable guys will tend to use the coax in an unused room for this purpose).


----------



## indigo (Dec 14, 2009)

svaic00 said:


> Thanks. With regards to some of the coax runs we have, there are two lines that go to bedrooms that have no tv's or cable boxes. The line just ends at the wall outlet in the bedroom. Should I cap the outlet in the wall with a 75 ohm cap in the bedroom, or should I actually detach those two lines from this splitter, and cap off those extra ports on the splitter? And then in time if/when we get a tv/cable box for that room, just reconnect the line(s) that are needed? OR is that not really much of an issue?
> 
> Thanks,
> Steve


Isn't that much of an issue. I wouldn't bother with either unless there's really an issue.


----------



## indigo (Dec 14, 2009)

ktkelly said:


> Since there is a passive return (two way signal passing), it will work with moca.


Moca is not the same as return path. Return path is effectively your upload from a modem -- what you send back to the ISP. Moca is communication within your house, which a non-moca certified amp can get in the way of. Not saying the one you linked to won't work (as I didn't look that closely) but it's worth a double check.


----------



## ktkelly (Apr 7, 2007)

indigo said:


> Moca is not the same as return path. Return path is effectively your upload from a modem -- what you send back to the ISP. Moca is communication within your house, which a non-moca certified amp can get in the way of. Not saying the one you linked to won't work (as I didn't look that closely) but it's worth a double check.




An amp without a return path will not work. An amp with a return path will.


The bottom line is that the original install WAS done improperly, and this, or any other amp with a return path is the correct way for it to have been done.

FWIW: although it really doesn't make all that much difference, having a 75ohm cap on any unused wall pate is a violation of the FFC rules. Rules that hardly anyone bothers going by of course.


----------

