Television cabling question(s)

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Old 09-04-12, 02:54 PM
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Television cabling question(s)

To any cable TV experts out there... I know that using a splitter on a coaxial cable will degrade the signal somewhat. This may be a dumb question but... Does the signal suffer from simply being attached to the splitter? Or does it suffer when multiple televisions are actually using the signal? In other words, if I run a coax into a 2 way splitter, but have a single television connected to one of the legs, will I still have signal loss on that one television?

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Old 09-04-12, 03:13 PM
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I researched this recently and the answer is yes, the signal will degrade anyway, based on what I read, but I don't remember where I read it. They make terminator caps that reduce or eliminate the problem but I'm afraid to link to them or mention where they're sold because I tried that with another product recently and the post was deleted.
 
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Old 09-04-12, 06:36 PM
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You should be able to find the termination caps at your home store, or electronics type store (IE: Radio Shack) Also, you get what you pay for when it comes to splitters. Spend the $6 rather the bargain bin 99 cent ones.

@ Borad - You can suggest a store by name as an example as I did, but do not link to their site.
 
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Old 09-05-12, 01:48 AM
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A splitter does not degrade the signal, but it does cut the strength of the signal by half (3dB) for every doubling of ports. It also has an "insertion loss" of about .5dB (point-five). This loss happens at the splitter's outputs whether or not there are devices connected.

Terminators protect the cable system from ingress (noise entry through unused ports) and egress (signal bleed), but they don't affect the signal quality or strength in any way.
 
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Old 09-05-12, 06:39 AM
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Thanks Rick... Just to make sure I understand... Sounds like you are saying that the signal will be split between the outputs whether those outputs are connected or not. Correct? If this is the case, is there a device or some other type of splitter where one could direct the full signal to one or more of the outputs? For example, is there a two way splitter where you could choose one or the other outputs without any signal loss, but would still be able to select both if you wanted to? Or even better, a four, six, or eight way splitter where you could set the signal to be split between whichever output(s) you choose? Seems like this would be a much better setup than just splitting the signal "across the board" regardless of how many outputs are being used.
 

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Old 09-05-12, 06:49 AM
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Thanks Tolyn, I feel like I'm blindfolded when shopping for a splitter. How can you determine if you are buying a quality product?
 
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Old 09-05-12, 08:32 AM
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A page on the website of a DIY magazine says "Judge a splitter by the numbers. If you have cable service, buy one labeled 5-1450 MHz. For satellite TV, look for a high end of at least 2200 MHz." Cablevision sent me a splitter that's rated to something below 1450 MHz for my modem and it seems to work fine. I even subjected it to some vibration when I cut the mounting and grounding holes off so it would fit in a 2" raceway and no apparent problem.
 
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Old 09-05-12, 09:17 AM
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Short version is use the smallest splitter you can - don't use an eight way to go to two TVs.
 
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Old 09-05-12, 01:52 PM
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Borad, Thanks for the info on specs. The problem is though that you can find splitters with similar specs but vastly different prices. You can always go the route of assuming a higher price yields a better product but that is not always the case.
 
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Old 09-05-12, 02:00 PM
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Mitch, I guess that's the most straight forward approach, and that would be fine if you only had two TVs that never get moved. But if you have a house with eight rooms all wired for cable, then I suppose you might need to keep several splitters on hand and also swap lines in and out as you move/add televisions. I was just wondering if there was a product similar to a patch panel so you could simply activate wall jacks as necessary.
 
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Old 09-05-12, 02:25 PM
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Off the top of my head, I have eight coax jacks in my house and I have three TVs and one PC hooked up. The initial feed is split by a two way with one leg going to the PC. The other leg is then split four ways, one going to each of three TVs and one capped. The third TV got added after everything was initially set up and it did mean I had to go get a new splitter, as there was only another two way there at the time.
 
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Old 09-05-12, 02:48 PM
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I'll often use a term like this in my favorite search engine:

"makes good splitters" coaxial

When a search like that returns too many commercial websites trying to sell me their product, I'll add the name of my favorite commercial message board software (which happens to be the same that this forum uses but I'm still afraid to say it) to the search term so I'll get discussions rather than ads.

My splitter is currently in conduit that I'm not allowed to touch, but if you could find out what splitter an ISP includes in their self-install kit, or what an ISP installs themselves, I think that would be a clue to quality. But I wonder if an ISP likes a certain number of service calls.
 
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Old 09-06-12, 01:45 AM
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Blonger-Tongue and Toner are two quality brands.

Three-way splitters come in two flavors: A "balanced" 3-way divides the signal evenly between the three output ports, and the "unbalanced" 3-way has two of the ports at higher dB loss than the third. Other than that, all splitters' ports are equal.

Today's typical home is wired with as many splitter ports as there are rooms, plus a couple of spares. An amplifier is inserted prior to the splitter to make up the loss. Most cable systems have a bandwidth of 1GHz (1,000MHz), so 5 - 1GHz splitters will work fine.
 
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Old 09-06-12, 03:34 AM
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Great info! Thanks everyone!
 
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Old 09-09-12, 01:54 AM
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If you happen to see one of your cable company's trucks around, ask the tech if you can buy a splitter or two off of him. Usually they'll give you one or two for free, or they'll sell them to you for a couple bucks. They use really good ones.
 
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