someone tell me about cable amplifiers

Discussion in 'Beginners, General Questions' started by Vince Maskeeper, Jan 26, 2004.

  1. Vince Maskeeper

    Vince Maskeeper Producer

    Jan 18, 1999
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    I have a cable splitter in my house, a passive one, currently feeding 3 sets. I'd like to be able to feed one or two more, and I'm sure the first three are already suffering from the split, so I thought adding some sort fo line amp would be the way to go. But I had some questions:

    1) It seems like radioshack carries one of these, but the amplifier level is not variable. I come from an audio background and wonder immediately about the potential to OVER amplify a signal. Are these things automatically regulated? Do they just guess and hope the signal doesn't clip?

    2) It seems radioshack also has one that does offer a gain adjustment- is this a better idea? Is variable gain necessary- or is it usually ok with a fixed boost?

    3) Is there another source for these other than Radio Shack. I don't mind cehap- this is not overly critical- just trying to keep from getting a ton of noise in the line from hooking up to 5 TVs.

    Anyone have any advice on these things?
  2. Jim Rakowiecki

    Jim Rakowiecki Stunt Coordinator

    Sep 2, 2003
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    If you only have three sets you should still have plenty of signal at the back of the set. I'd get the cable guy out to check.
    I would also ask about the amp when he's there. If you have digital you may need a two way amp otherwise your return path would be blocked.
    If you want to buy your own look for fixed amp that has a 10db gain. unless you have an exceptionally long run in your house all you need the amp to do is overcome the loss in the splitter. Your three way should be losing about 5.5 db if it's working properly and a four way will lose about 7db, and a six or eight way splitter would lose about 10 db.
    In any case the gain from the amp is negligible and the signal gain shouldn't hurt your TV's.
  3. Bob McElfresh

    Bob McElfresh Producer

    May 22, 1999
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    It might be more than you are ready to spend, but I wired a house from a central distribution point with a Channel Plus amplifier/splitter for $125. While it did not have variable gain, it did have slant compensation for longer runs and the outputs were clearly marked for the longer runs of coax.

    (This means it amplifies the higher-frequencies more than the lower frequencies for the longer runs of coax to avoid over-amplifying the channels that travel well down long coax.)

    Before this, I was re-buying the Radio Shack amplifiers every 2 years or so. They just seemed to go belly-up every few years. The Channel Plus unit lasted 5 years and was still going strong when I sold the house.

    I would recommend you buy the little termination-resistors from Radio Shack and cap off any un-used outputs on your splitter. This can help prevent reflections. They are nice and cheap.
  4. Wayne A. Pflughaupt

    Aug 5, 1999
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    Katy, TX
    Real Name:

    I’m not an expert on this stuff, but I’ll give you what I do know.

    Personally, Vince, I wouldn’t worry about it unless you find that you have a problem after you make your connections. If that turns out to be the case, try using the amplifier in front of the splitters.

    The cable TV people frown upon this, but I configured my house so that the most important equipment (i.e. the home theater system) gets the strongest signal. That is, one side of the split feeds the system and the other side is further split to feed everything else. I haven’t had a problem at any location with this arrangement.

    Wayne A. Pflughaupt
  5. PaulT

    PaulT Supporting Actor

    Oct 28, 2002
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    I've been using an RS amplifier / splitter (15-1116X) for about 3 years now. The unit has a fixed gain of 8db per output. It is in front of another splitter as per Wayne's post above. I have digital cable and there has been no problems with it. The cable guy wasn't bothered by it when he was looking for another problem in the house.

    Here's the link from Radio Shack Canada,
    I couldn't find an equivalent part on the US site, but they do have a couple of bidirectional CATV amps listed:
    15-1195 (1 TV) and 15-1197 (4 TV's).

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