Splitting Cable Internet

Geronimo

Thread Starter
Supporting Founder
Supporting Founder
Lifetime Supporter
Sep 9, 2003
11,840
1,435
I was splitting my cable signal for years. i split it in the attic to go to several room. One of those rooms which I call the Man Cave is where the Cable modem was. In that room I was splitting it two ways to go to the cable modem and to a DVR+D Recorder. i recently decided to split it three ways to also go to the TV.

About two weeks later I started to experience loss of internet connection. I have tried upgrading the 3 way splitter to one handling 5-2400 MHz For only $3.30 each when QTY 50+ purchased - PREMIUM 4 way Coax Cable Splitter F type Screw - 5~2400 MHz (for Video VCR Cable TV antenna) | Video Splitters From F-Type
and have tried amps one from rocketfish and one that was recommended bya friend Amazon.com: 4 PORT CABLE TV / HDTV / DIGITAL AMPLIFIER INTERNET MODEM SIGNAL BOOSTER INTERNET AMP: Electronics.


None of this solved the problem. Right now I have replaced my old splitter in the attic with the Amp shown above. That temporarily allowed me to get signal in the man cave but eventually the same problem recurred. I finally just went from the wall to the modem with no splitter but that means no cable on the DVD recorder or TV.


Are there any thoiught ona better way to make that final split?
 

RandallA

Supporting Founder
Supporting Founder
Dec 13, 2004
10,550
59
San Francisco Bay Area
As you have already found out, going straight from the wall to the modem works because there is less loss. Because your signal is not that high, you should try the amp at the point of entry in the house. The 4 way splitter you bought at Monoprice has too much loss IMO. I have a 3 way splitter that has one leg loss at 3.5 db and the other two at 7 db. You should find something similar so you use the 3.5 db leg for the modem.

What signals are you getting at the modem? With and without splitters. For most modems you can check the signal by going to 192.168.100.1.
 

grohgreg

SatelliteGuys Pro
Aug 21, 2008
523
1
Dawson Springs, KY
Yeah, it's a signal loss compounded by confusing signal grounds. The basic problem is that your internet connection is bi-directional, the other signals are uni-directional. I personally wouldn't split them at all, I'd dedicated the internet. But if you have no other choice, use a 2-way splitter at your service entrance. One output for the bi-directional computer modem, the other for the uni-directional video stuff. That way you only lose 3db going to the cable modem. Not that 3db is insignificant, it actually represents half power (as opposed to no splitter at all).

Anyway - then put a 2nd splitter on the unidirectional (video only) port. For my money it's better to suffer a bit on picture quality than it is to squander internet speed. And I wouldn't cheap out on 2.4 GHz stuff either. I buy minimum 3GHz fittings, and the 4GHz hardware has started to become reasonably priced now as well.

//greg//
 
  • Like
Reactions: Stargazer

rcbridge

SatelliteGuys Pro
Sep 22, 2003
583
0
Limerick Pa
As stated I would take the feed into your house and use a 2 way splitter and use one leg to feed the cable modem and the other for all else.
A higher frequency rated splitter is not needed.
The problem you are seeing is most likely due to the Upstream levels needed to complete the 2 way communication, that amp is actually acting like a 4 way splitter for the return path signal (7db loss).

Just split the signal with a 2 way and run a line directly to the modem take the other and feed the 4 way amp and distribute as needed.

Once your modem is working put 192.168.100.1 into your browser this should give you the modem diag screen, then check the up and downstream levels.

Let us know what they are.
 

grohgreg

SatelliteGuys Pro
Aug 21, 2008
523
1
Dawson Springs, KY
A higher frequency rated splitter is not needed.
You're going to have a hard time supporting that position. It's a physical law that - ass frequency rises - so does resistance. So the higher the frequency rating of a fitting - including splitters and amps - the lower the resistance to throughput. Point in case, the old 900 MHz analog cable splitters. Would you have any reservations in recommending one of them? If yes, then the same reservation is applicable to 2.4GHz versus 3.0 or 4.0 GHz rated stuff

Besides that; the negligible cost difference between/among 2.2/2.4/3.0/4.0 GHz rated fittings make it foolish not to overbuild.

//greg//
 
Last edited:

RandallA

Supporting Founder
Supporting Founder
Dec 13, 2004
10,550
59
San Francisco Bay Area
Sorry but I agree with rcbridge, there's no need for a high frequency splitter. The cable frequencies go up to around 900 Mhz. Any splitter rated to up to 1000 Mhz should be fine.
 

grohgreg

SatelliteGuys Pro
Aug 21, 2008
523
1
Dawson Springs, KY
Moving on. Besides selecting a digital splitter and/or amp with the lowest throughput resistance, all unused splitter/amp ports should be terminated with 75 ohm plugs to balance signal ground.

//greg//
 

stardust3

SatelliteGuys Master
Pub Member / Supporter
Lifetime Supporter
Mar 7, 2006
8,024
5,578
.....
It is possible you have a bad drop also. There are too many possibles here. You have to have good signal/return to begin with @ tap. The drop whether it's overhead or underground has to be in decent shape. Overhead drops can water log in as little as 10 yrs. Quality connectors, cable and splitters are essential also.
Your best starting point is to get on the phone with tech support and have them run an eqa test or the equivalent of their own test. This will point you in the right direction. Intermittent modem sync can also be a modem problem. There is too many variables. There is 1 simple rule I always followed regardless of splitters, +10 To -10. Without having the right test equipment to check signal & return it is just a guessing game. I'd start with a call to tech support & go from there.
 

rcbridge

SatelliteGuys Pro
Sep 22, 2003
583
0
Limerick Pa
The basic problem is that your internet connection is bi-directional, the other signals are uni-directional
I don't know what type of Cable boxes the OP has but keep in mind that most are bi-directional this is what allows you to have Video on Demand or PPV items.

Today most cable systems are below 900mhz and I truly don't expect them to go much higher.
 

rcbridge

SatelliteGuys Pro
Sep 22, 2003
583
0
Limerick Pa
To the OP getting tech support is a good idea but if you want to try something yourself I would do the following.
Put the 2 way back in line and if your modem is working okay type in 192.168.100.1 into your browser you should get the diagnostic screen for the modem.
Look for the UP and downstream levels at the modem.
Your D/S should be somewhere between +10 and -10dbmv.
Your U/S should be somewhere between +55dbmv (max) and anything lower.
If the U/S is about that 55dbmv range when you added the 3 way your modem needs to work harder (more power) which it can't do so you lose your U/S going back to the CMTS.
Again if it works with the 2 way back in line and your numbers are are close to the edge of the UP or Down stream when you add additional attenuation (3 way splitter) that is the cause of your problem.
At a minimum I would ask the cable company to measure the power into your home.
Let us know what happens if you do any ofthese things.

Good luck!!
 

Geronimo

Thread Starter
Supporting Founder
Supporting Founder
Lifetime Supporter
Sep 9, 2003
11,840
1,435
As you have already found out, going straight from the wall to the modem works because there is less loss. Because your signal is not that high, you should try the amp at the point of entry in the house. The 4 way splitter you bought at Monoprice has too much loss IMO. I have a 3 way splitter that has one leg loss at 3.5 db and the other two at 7 db. You should find something similar so you use the 3.5 db leg for the modem.

What signals are you getting at the modem? With and without splitters. For most modems you can check the signal by going to 192.168.100.1.

There is an amp where the signal enters the house. There was before too. Right now I have replaced the original amp with the amp I mentioned above but cannot even split the signal two ways in the room (even though I could until recently). I still can't split it in the mancave.

Tech support told me I had no problem and that i could not have spit the signal before.


As for getting a splitter with a lower range down to 5-1000m would that be better than the splitters I have tried recently? If not why trade down? I reaaly don't understand that guidance but maybe I am missing something.


satellite internet is out. I would rather be stuck in the current situation with internet but no cable to the TV or DVD recorder.

In fact that is pretty much where I am leaving it. Keeping the internet and getting TV from another source.


As for cable boxes Ia m not using a cable box. I am trying to go straight to a TV and a DVD recorder with QAM tuners.


Sorry if I sound frustrated. It is not with you guys it is with the situation and tech support.
 
Last edited:

stardust3

SatelliteGuys Master
Pub Member / Supporter
Lifetime Supporter
Mar 7, 2006
8,024
5,578
.....
There is an amp where the signal enters the house. There was before too. Right now
I have replaced the original amp with the amp I mentioned above but cannot even split the signal two ways
in the room (even though I could until recently). I still can't split it in the mancave.

Tech support told me I had no problem and that i could not have spit the signal before.


As for getting a splitter with a lower range down to 5-1000m would that be better than the splitters I have tried recently? If not why trade down? I reaaly don't understand that guidance but maybe I am missing something.


satellite internet is out. I would rather be stuck in the current situation with internet but no cable to the TV or DVD recorder.

In fact that is pretty much where I am leaving it. Keeping the internet and getting TV from another source.


As for cable boxes Ia m not using a cable box. I am trying to go straight to a TV and a DVD recorder with QAM tuners.


Sorry if I sound frustrated. It is not with you guys it is with the situation and tech support.
That very well could be the problem. Have you tried bypassing the amp? Amps are not created equal. The best ones I've used are similar to an amp but are called a zero loss splitter. They pass two way easily & have the same signal on all outputs as the input signal, they are also powered like an amp.
You should try bypassing the amp & as a test have a single home run from the cable drop ground block/demarc to the modem. If that works start introducing a splitter at a time for your other runs and checking to see how pictures look & if modem is synced up. The best scenario is 1 splitter location & all runs coming back to that point. This eliminates the need for an amp or zero loss splitter a lot of times. Typical splitter losses are 3.5 on each leg of a 2 way, 3 ways can come either 3.5, 7, 7 or 5,5,5. 4 ways are 7,7,7,7, & 8 ways lose 12 on all ports. Signal losses can accumulate quick with multiple splitter locations. If a 1 location splitter is not an option go your attic & put the room where modem is on 1 leg of a 2 way & feed the other leg to a splitter to accommodate the rest of your runs. That will get you the most signal where you need it. Catv is finicky and varies from place to place & highly depends on your internal wiring & the amount of splitters, amps, etc. I know your frustrated, but isolate the problem by bypassing everything and introduce the components 1 at a time until you find the problem.
 

stardust3

SatelliteGuys Master
Pub Member / Supporter
Lifetime Supporter
Mar 7, 2006
8,024
5,578
.....
After reading a little more on the amp you bought I see that only 1 port is bi directional. If your modem is not on that port you will not have internet.
 

stardust3

SatelliteGuys Master
Pub Member / Supporter
Lifetime Supporter
Mar 7, 2006
8,024
5,578
.....
Extreme IPA1008D-RSVF Cable TV, Modem, Signal Amplifier | eBay

This is without a doubt the best zero loss splitter/amp out there. It is completely bidirectional on every port, which means a cable modem, cable box(VOD) or mta(voip) will work off any port. It also has a passive port that many cable companies require their installers to use for modem/voip installs. This is a truly a gem for a household with many cable runs.
 

rcbridge

SatelliteGuys Pro
Sep 22, 2003
583
0
Limerick Pa
Do you still have the old amp?
If so you could try putting it back in line and trying the modem test.
The new one while boosting the forward (D/S) signal strength is also lowering the Return (U/S) signal that the modem needs to send info back to the CMTS.
You need an amp that has either an active return or minimal loss. The link that you posted in the original post, contains such an amp as an alternative but that has 8 ports.
 

Geronimo

Thread Starter
Supporting Founder
Supporting Founder
Lifetime Supporter
Sep 9, 2003
11,840
1,435
things are better (not worse) since i replaced the amp but still too inconssitent I will continue to look for a suitable replacement.
 

Geronimo

Thread Starter
Supporting Founder
Supporting Founder
Lifetime Supporter
Sep 9, 2003
11,840
1,435
Extreme IPA1008D-RSVF Cable TV, Modem, Signal Amplifier | eBay

This is without a doubt the best zero loss splitter/amp out there. It is completely bidirectional on every port, which means a cable modem, cable box(VOD) or mta(voip) will work off any port. It also has a passive port that many cable companies require their installers to use for modem/voip installs. This is a truly a gem for a household with many cable runs.

thanks I am currently hooked up to the bidirectional port but this looks worth investigating especially at that price. As for those who think I am using the wrong port---remember that the amp is in the attic which is the entry point. The problem is the sudden inability to split the signal in the room that has the modem. If i had the wrong port in the attic I would have no internet in that room whether I had it split or not.
 
Last edited:

RandallA

Supporting Founder
Supporting Founder
Dec 13, 2004
10,550
59
San Francisco Bay Area
Geronimo,

Have you been able to check the signal levels on the modem? It would make things easier and would allow you to compare signal levels when you make changes. Go to: 192.168.100.1, Diagnostics.
 

Users Who Are Viewing This Thread (Total: 1, Members: 0, Guests: 1)

Top