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I have a cable TV plus Internet coming into the house and into an 8-way splitter (CE Tech Home Command Center). From this splitter I have coax going to the cable modem plus 3 TV's. When I have my cable provider refresh my signal everything works fine for about two months. Then the interet gets gradually slower, and I have to have a signal refresh again. When I take the splitter out, the internet is back to full strength.

My question is how can the splitter gradually degrade the signal? It is just physical coax connections, no amplification or other electronics. I don't see how it can work on day 1 and gradually get slower.

Also, I could split the cable from outside, connect one to the modem and the other to the command center for the 3 TVs. Or I could buy a signal amplifier and boost the signal before it gets to the command center. Any recommendations on this?

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I can't speak to gradual degradation but you don't want to be splitting the signal that much without a powered splitter. I'd look into a powered splitter and see if that fixes things. – DA01 May 28 '14 at 1:11
One reason that your signal can degrade over time is changes in the network outside your home. Every time they add someone else to your local loop, your signal level goes down a fraction. The cable companies should be monitoring those levels; your cable boxes and modems report their signal levels back for precisely this reason. When they notice, then they either split the loop or they boost the transmit output for that loop. That's in a perfect world, though. – longneck Jul 6 at 18:22

It sounds like you might just be dealing with a bad splitter, so my first recommendation would be to just replace the splitter.

There is a loss associated with every port on the splitter. If you look on the splitter, you'll probably see something like -4dB printed on each port. This is how much signal loss there is on that port.

Typically your cable modem will be connected to a splitter directly from the source feed, then all other TVs split from a secondary splitter.

Amplifiers usually just add noise and if there is a signal quality issue, it's best to work with your service provider to get the addressed.

Bad connector fittings on the end of the cable can make a huge difference, as can the length and quality of the cable used. By SOP, most cable installers would probably replace every RG6 compression fitting between the source and the modem.

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A couple follow-on points: 1) the more outputs a splitter has, the more signal is lost, even if some of them are unused. 2) Higher quality splitters lose less signal. Look for the dB rating, as you say. 3) Some splitters are "unbalanced" meaning the outputs have different strengths. This may be useful for something like an internet modem, which you would want on the strongest signal. – Henry Jackson May 27 '14 at 20:29
Unbalanced is known as a Tap. Charter recommends the first splitter be a tap with the low loss leg going to the cable modem. – Fiasco Labs May 27 '14 at 20:40

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