# Coax splitter



## miamicuse (Nov 13, 2011)

If I have ain incoming coax cable that is connected to a two way splitter inside the wall, then one end runs to a wall jack that's connected to a digital cable box (Comcast), the other end runs up to the attic and down to another room's wall jack but there is no TV or cable box connected to it,

Is the signal going to the cable box still "degraded" by the splitter even though the other end is not used?

I understand that there are coax "terminators" that you can use to cap off unused connections, does doing so gives better quality and signal to the actually used connections?


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## Guap0_ (Dec 2, 2017)

Yes & yes. The splitter lowers the signal & there are caps available.


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## del schisler (Aug 22, 2010)

miamicuse said:


> If I have ain incoming coax cable that is connected to a two way splitter inside the wall, then one end runs to a wall jack that's connected to a digital cable box (Comcast), the other end runs up to the attic and down to another room's wall jack but there is no TV or cable box connected to it,
> 
> Is the signal going to the cable box still "degraded" by the splitter even though the other end is not used?
> 
> I understand that there are coax "terminators" that you can use to cap off unused connections, does doing so gives better quality and signal to the actually used connections?


been doing this for yrs and the line comes in and to the center of the splitter and that 1 end to the box and the line out of the box to tv? that works ? now the other line out from the other end of splitter goes to the other run and it need a box for tv their that line will not degrade the signal where you will notice may 4 or d db's which is not much , do this hook up tv look at pic and than disconect the other line see and difference ?? bet not


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## ktkelly (Apr 7, 2007)

You are not going to see any difference if you remove that splitter.

No way, now how.

Assume 7db incoming (as required), the splitter having a 3.5db insertion loss, will still have you on the plus side.

In the ideal situation you will have 0db at the TV, but as long as the signal isn't too hot, you will be fine.

Honestly, all will work well at near -7db.

In other words, don't worry about it.


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## carmusic (Oct 11, 2011)

didnt think that some cable provider still use co-ax, here everything is cat5e or wifi


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## ktkelly (Apr 7, 2007)

carmusic said:


> didnt think that some cable provider still use co-ax, here everything is cat5e or wifi



On what planet do you reside? :devil3:

Service to the home is going to be either coax, or fiber, and there are very few places that have FTH (fiber to home).


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## MTN REMODEL LLC (Sep 11, 2010)

Don't know the veracity of this, but the cable guys (installers) have said very similar to above.

That multiple splitters (used or unused) do eat up some of the signal, but in most practical applications, should not be a problem.

And that they cap unused splitters/coax-end to shield them from picking up any interfearance.


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## ktkelly (Apr 7, 2007)

MTN REMODEL LLC said:


> Don't know the veracity of this, but the cable guys (installers) have said very similar to above.
> 
> That multiple splitters (used or unused) do eat up some of the signal, but in most practical applications, should not be a problem.
> 
> And that they cap unused splitters/coax-end to shield them from picking up any interfearance.



A splitter downstream, after a splitter, CAN be a problem. It's just a math issue though. Most often see problems with larger structures and businesses where there are a lot of drops.

Used to be a FCC rule that unused "active" coax connections had to be capped. It was to prevent "leakage". I don't know of anyone doing that any longer. Don't even know if the rule is still in effect.


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## MTN REMODEL LLC (Sep 11, 2010)

ktkelly said:


> A splitter downstream, after a splitter, CAN be a problem. It's just a math issue though. Most often see problems with larger structures and businesses where there are a lot of drops.
> 
> Used to be a FCC rule that unused "active" coax connections had to be capped. It was to prevent "leakage". I don't know of anyone doing that any longer. Don't even know if the rule is still in effect.


KT..... Now my curiosity is begging..... what is "leakage" in reference to a coax cable signal..... any idea.???


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## ktkelly (Apr 7, 2007)

MTN REMODEL LLC said:


> KT..... Now my curiosity is begging..... what is "leakage" in reference to a coax cable signal..... any idea.???


I always had to laugh about the term myself. Always picture a water fall picture coming out of the wall plate.

I believe what they were referring to is the fact that there is voltage in the line, however small it may be (it's measured in millivolts), and someone thought some of the voltage would leak if the line wasn't capped.

I really have no idea, as I was just the guy that could design the distribution network and have it work as it should. 

As to the interference issue, generally the shielding in the coax takes care of that, unless you're installation is near some high power lines, then you go to quad shield in an effort to get it down to acceptable levels.


Truth be told, that mention of data wiring and WIFI isn't far off the mark. In a distributed audio/video system, both data wiring Cat5e/6/7, or even some wireless options are available. Wireless I wouldn't fool with as it's just not that stable. But, cat wiring is used quite a bit. Especially so now, what with the HDMI thing being so prevalent.

Fun biz to be in, although I really enjoy building and remodeling. Enjoy fixing up old cars too.


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## FrodoOne (Mar 4, 2016)

miamicuse said:


> I understand that there are coax "terminators" that you can use to cap off unused connections, *does doing so gives better quality and signal to the actually used connections?*


The "loss" caused by any 2-way splitter will be at least 3.1dB (and, actually, a bit more.)

A "cap" or "Terminator" - at the "Characteristic Impedance" of the cable concerned, (usually, 75 Ohms) is used to prevent "Standing Waves" being generated, at a particular frequency, on an un-terminated length of cable. (http://www.ebay.com/bhp/75-ohm-terminator)

Such a "Standing Wave" may act to cancel out a small range of frequencies, which may be seen as "interference". 

(In the early days of analog Colour Television, I have seen a "situation" due to a "Standing Wave" where the color-burst signal of one local TV channel was cancelled out, preventing colour being received for only that Channel on the TV concerned, but with a perfectly normal monochrome picture for that Channel - and colour on all the other Channels.)


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## rcicatello (Mar 11, 2018)

A splitter wont harm the signal if it is not faulty. Most cable systems are designed to support at least a 3 way splitter at the entry point. As for terminating the unused line, it is recommended to avoid any possible ingress issues caused by FM Band or HAM radio users nearby. Remember a coax system is designed to be closed so any open ports is a possible issue in the right environment.


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## ddawg16 (Aug 15, 2011)

FrodoOne said:


> The "loss" caused by any 2-way splitter will be at least 3.1dB (and, actually, a bit more.)
> 
> A "cap" or "Terminator" - at the "Characteristic Impedance" of the cable concerned, (usually, 75 Ohms) is used to prevent "Standing Waves" being generated, at a particular frequency, on an un-terminated length of cable. (http://www.ebay.com/bhp/75-ohm-terminator)
> 
> ...


Another term for 'standing wave' is 'reflected wave'. Otherwise, all the above it correct.



rcicatello said:


> A splitter wont harm the signal if it is not faulty. Most cable systems are designed to support at least a 3 way splitter at the entry point. As for terminating the unused line, it is recommended to avoid any possible ingress issues caused by FM Band or HAM radio users nearby. Remember a coax system is designed to be closed so any open ports is a possible issue in the right environment.


Mine didn't. 3-way splitters (3 outputs) means one output is about 3.5 db loss....the other 2 are down about 7db or more.

The other issue....if you are using cable for internet....your modem may not put out enough power to overcome the loss in the splitter.

And....not all splitters are equal. You have to look at the freq range....it needs to be good to at least 1 Ghz...which is where most of the providers put the internet signal


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## rcicatello (Mar 11, 2018)

DDAWG you are correct. the HSD Downstreams are usually on the higher end and not all splitters are equal. just dont buy gold Radio Shack Splitters lol. Your unbalanced(3.5 hot leg and 7 on the down legs) is what you would want when you seperate a particular leg for a modem and the others to feed additional splitters. Balance 3 ways are 5.5db on all 3 legs and treats ever outlet equal. Most MSO's dont seperate modems anymore because todays Converters are modems for VOD and Interactive features.

As long as the downstreams are within range splitter configs are not important. personally I prefer all home runs and a single splitter unless you have more than 8 outlets.


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## ddawg16 (Aug 15, 2011)

rcicatello said:


> DDAWG you are correct. the HSD Downstreams are usually on the higher end and not all splitters are equal. just dont buy gold Radio Shack Splitters lol. Your unbalanced(3.5 hot leg and 7 on the down legs) is what you would want when you seperate a particular leg for a modem and the others to feed additional splitters. *Balance 3 ways are 5.5db on all 3 legs and treats ever outlet equal.* Most MSO's dont seperate modems anymore because todays Converters are modems for VOD and Interactive features.
> 
> As long as the downstreams are within range splitter configs are not important. personally I prefer all home runs and a single splitter unless you have more than 8 outlets.


The 3-way I had was 3.2 on one leg and 7.5 db on the other 2 legs. 

But I now use a powered amp (bi-directional) and it works like a champ. We 'were' using it for the cable....but when our provider decided they wanted to use a decoder box to watch even local channels...we went OTA and the cable is just for internet. 

We have 4 TV's in the house....all smart TV's...so we can watch OTA or stream from Amazon or Netflix. Who needs HBO?

This is my 'data central' setup.....yea, I know, I need to clean up the wiring....saving that for a rainy day....


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