coax spliting 101

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bth0mas20

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Maryland
I need a rundown of the do's and dont's of spliting coax cable for cable and direct tv/ dish tv.

Im ok with spliting cable tv. What are your recomendations for db's or mhz and how many times you can split it before the pic gets worse?

Also mostly is it possible to split direct/dish tv or do you have to make a run all the way back to the main splitter? If so what kind of spliter do I use?
 
bth0mas20 said:
Also mostly is it possible to split direct/dish tv or do you have to make a run all the way back to the main splitter? If so what kind of spliter do I use?
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You cant use splitters with satellite. everything must be a homerun back to the multiswitch. You cant use diplexer's with Directv's new dish either.
 
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For cable, just think about a few simple things.

As a simple rule of thumb, figure the signal is coming in at +8dB, and don't let it go under +3dB. Every splitter has losses, written right on the splitter. For instance, a 2-way splitter has a -3dB loss per leg, so you'd be down to 5dB using the rules of thumb.

If you have a cable modem, split the incoming cable line with a 2-way immediately, and run the cable modem on one port of that 2-way splitter. Take the other leg to go to your TV's. If you need to run 8 Tv's, for instance, you're going to need an amp. Amp it first, before you split it! In our example, with a cable modem and 8 TV's, you'll run from that 2nd leg of that 2-way splitter to your amp. The amp will probably add +15dB. From the amp, run to your 8-way splitter. Each leg of that 8-way will go to each of your tv jack plates. Each port of an 8-way splitter has a -11dB loss. In our example, you'll likely have +9dB at each jack. (8 in - 3 for the 2-way + 15 for the amp - 11 for the 8-way = 9dB)
 
Great reply marc that helps alot.
What amp would you recommend?
also if my channels are fuzy in the lower channels and clearer in the higher ones would you think theirs a bad crimp somewhere?
 
bth0mas20 said:
also if my channels are fuzy in the lower channels and clearer in the higher ones would you think theirs a bad crimp somewhere?
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About 90% of the problems related to cable TV are bad terminations. By now, everyone should be using the Snap-n-Seal type connectors. Many manufactures make them. They're the cat's ass. Beyond simply replacing all the terminations, you need equipment to check levels to find out where things start to drop off. This equipment is prohibitively expensive for occasional use. You're immediately into a couple grand and up.

For amps, I favor those made by Extreme Broadband. Not only do I find them to be of high quality, but the lead from the wall-wart transformer to the amp can be made from co-ax, with regular co-ax connectors for a slick install. Some of their amps have built in splitters. Stay away from junk from Radio Shack or Wal-Mart.


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bth0mas20 said:
I need a rundown of the do's and dont's of spliting coax cable for cable and direct tv/ dish tv.

Im ok with spliting cable tv. What are your recomendations for db's or mhz and how many times you can split it before the pic gets worse?

Also mostly is it possible to split direct/dish tv or do you have to make a run all the way back to the main splitter? If so what kind of spliter do I use?
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You need multi-switches for splitting sat signal. Solid Signal should have what you need; some local electronics shops have the equipment.
 
bth0mas20 said:
do I need to buy a transformer to feed the amp? How does that work?
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The one in my picture comes with the little plug-in transformer. Most amps just come with a cord on them. The fact that you make your own "cord" with the Extreme amps is one reason I like them so much. You could, and I have, plug the amp in a bedroom someplace in the house, backfeed the 12 volts through an unused TV jack plate, and to the amp in the basement. Saves installing a receptacle in an old basement without any.
 
mdshunk said:
Any minute now, Hal will post that electricians have no business installing TV cable. Love you Hal. :)
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I think electricians have no business doing low-voltage work. It's far too specialized.
 
Marc or Peter, When you guys rough in a house up there, are you required to do the low voltage, cable, phone ,ect or does someone else do it. I'm still learning that stuff, just because I'm doing House's now? Any good books on the subject manner?
 
jmsbrush said:
Marc or Peter, When you guys rough in a house up there, are you required to do the low voltage, cable, phone ,ect or does someone else do it. I'm still learning that stuff, just because I'm doing House's now? Any good books on the subject manner?
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Required to? No. But if I don't, nobody will. It's easy work, in reality. Just home run everything and you're good. Most homes I do get a phone and cable home run to each room, sometimes two places in each room, and the whole bundle is just left to hang out of the side of the house at the demarc location.
 
mdshunk said:
Required to? No. But if I don't, nobody will. It's easy work, in reality. Just home run everything and you're good. Most homes I do get a phone and cable home run to each room, sometimes two places in each room, and the whole bundle is just left to hang out of the side of the house at the demarc location.
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Cool, thanks My last house I had subbed out, but now he works for me. Our next house coming up has allot of cable.
 
Yeah, pretty much what Marc said.

It's pretty much assumed that the electrician will take care of the low voltage work here. The only exceptions to that are the alarm systems (generally) and really large custom homes.

Commercial work is another animal though. That work is usually broken up by system and done by a specialty low voltage contractor or lo-voltage division of an electrical contractor.
 
SiddMartin said:
running the LV is an easy upsell
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'Round here, it's just part of the job. The only time an LV contractor gets involved in resi is when there's alarm work or a home theater system involved. They can sometimes snatch the phone and cable work out from under the EC if you're not proactive about it. Certain times, it might be better for them the handle that work though, depending on how much systems integration is planned.
 
peter d said:
I think electricians have no business doing low-voltage work. It's far too specialized.
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And I think you are completly wrong. Lets take myself for an example: I have been learning about electricity since I was 10, out of high school I took some college courses and became certified by the FOA [Fiber optic associasion] took a few tests and passed the copper and fiber part of the class. I know how to run the cable [any low voltage] the proper way, as well as terminating it the proper way. Then I became an electrician. So, I am an electrician that can also do low voltage, and for someone to say I have no business doing it should just step back. The electricians that have never learned how to pull/termininate low voltage have no business doing it, but not every electrician in general.

~Matt
 
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