What kind of Coax Splitter is best?

Old 10-11-18, 02:29 AM
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What kind of Coax Splitter is best?

I have collected about 40 different coax cable splitters in my days dealing with Comcast. They all have different ratings and different uses. I do not know what the ratings mean or which connections are important for Internet vs TV.

Can someone please tell me what the dB ratings on coax splitters mean?

What about the MhZ rating, the EMI rating and whether digital or analog is best?

If there are different ratings for output, which is best for TV and which works best for the Internet?

Most of them have grounding screws, do they need to be wired to a dedicated ground or can they be grounded on the box the cable comes out of? Or can they be grounded to the plumbing?

Is it required?

Do they need to be shielded or can they run next to other wires?

Are there some brands that are better than others?

Is there anything I should avoid when splitting out my TV and Cable Modem connections?

What about source cables that have the extra wire with them, should that be attached to the grounding terminal?

Currently, I am having T3 Timeouts on my Cable Modem that the cable company thinks is a bad cable. I am running a new RG6 quad cable from their box to my single splitter. I am not having timeouts on my DVR (the TV side of the splitter), but I am on the much shorter run to my cable modem. I have replaced all the cables, but not the splitter until I know how to pick the best splitter for the job.

Any help would be greatly appreciated.

I have read the articles on here about coax cable splitters and I have to say that I am a little shocked about the quality of information provided. To split them into the 5 categories they mentioned seems like a humor piece rather than a useful article. In fact, they forget Vertical Flex Mount as one of the hilarious categories.
Old 10-11-18, 01:01 PM
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a 5 - 1000mhz splitter should be fine. You can read a lot of tech data on the web, but the real question to ask is "what does your cable provider recommend?"
Old 10-11-18, 04:46 PM
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Minus 3 dB (decibels) means getting half of the strength of the original signal. Minus 6dB means getting a quarter of the original signal strength. Plus 3 dB means getting twice the signal strength (and would apply only if the splitter had a booster amp within it).

A passive splitter is not 100% efficient so with two output ports, each will deliver a signal strength a little less than half the original, Minus 3.5 dB is considered good.

The 5 to 1000 mHz figures should stand for the frequency bandwidth. This correctly is the frequency range where the frequency that comes out worst is at least half the strength of (no more than 3 dB down from) the frequency that comes out best. Usually it is the low end and the high end that come out worse than the middle. This discrepancy is stacked or combined with the split loss in the sense that when an output port delivers the signal minus 3.5 dB then within the bandwidth stated the frequencies will come out anywhere between -3.5 dB and -6.5 dB.

I am not sure what frequencies are used by what cable or satellite systems for TV but if I remember correctly, channel 2 is always 54 to 60 mHz and FM broadcast radio is 87.9 to 108.1 mHz., What frequency range the splitter has to span depends on the actual frequencies used for the desired TV channels and the actual frequencies used for the internet signals.

Last edited by AllanJ; 10-11-18 at 05:05 PM.
Old 10-12-18, 10:44 AM
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Modems are usually "first on the line" (in other words, they need the strongest signal). They should have only only 1 splitter in front of them and should be on the tap with the lowest attenuation.

Electrical codes require that external devices be grounded just prior to entering the building. Do not ground at additional locations; that will likely create problems.

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