weird problem: My cable modem only works with one coaxial cable.

Discussion in 'OT Technology' started by Accido, Sep 20, 2003.

  1. Accido

    Accido New Member

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    And surprisingly It's not even the one Adelphia set it up with. Okay, so my cable modem was working fine for two months, then this past week the connection has been extremely flaking, getting worse as times passes. I troubleshooted everything but the coaxial cable, so I checked behind the walls where it's stored for chewing, crimps, or loose connection and everything was fine. So I changed the cable coming from the wall to the modem with an older one and it worked. Puzzled, I then tried every coaxial cable in the house, 6 all together, and only one works, which wasn't even the original cable. Anyone else experience this? All coaxial cables still receive singles for digital cable but dont want to work with the modem, except that one. :confused:
     
  2. d0rkus

    d0rkus I has a booger. OT Supporter

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    weird
    what comcast/att did, or what they said is that they usually have the main coax cable to your modem...then split the rest, to the toher room for the TV..
    so the modem should get the best reception or something like that
    :dunno: if that helps
     
  3. Accido

    Accido New Member

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    It does :) I asked them to install another drop and wire it directly to my cable modem, making a total of three I think, but somehow he talked me out of it and the modem is on two splitters. Maybe I should call adelphia
     
  4. Astro

    Astro Code Monkey

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    Coax, like twisted pair network cables, come in different flavors and different levels of insulation and shielding. The quality I bet you'd need is something heavy duty that is recommended to be used out in the backyard to be buried between your house and a sat. dish. Coax cables that go from the TV to the VCR probably won't cut it (depends on the cable company and what their voltage levels are like on the line).

    I've used some crappy cables and they would work under Time Warner. I go to Adelphia and you can see the crappy reception. Just swap the cable out with another and presto! All fixed.
     
  5. DatacomGuy

    DatacomGuy is moving to Canada

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    Astro is right..

    There are tons of variables when it comes to coax and related problems.. and its not just the cable. The quality of the splitter and connectors makes a big difference too.

    For high speed internet, a minimum of RG6 is required, although I always install or recommend RG6 Quad Shield, which gives maximum protection.

    Sounds like you have too many drops and your loss is too high at your desk. It's what happened at my apartment.. I had digital cable installed in living room and master bedroom, and then had it installed in the second bedroom and wanted to put TV and cable modem and couldn't because I had reached the end of the power available for my unit.

    Basically you may have too much going at once in the house. I'd recommend you call them with your problem, and they can better address the situation... but I can also tell you that splitting the coax for anything digital is a bad idea.

    Also - Chances are that the cables Adelphia gave you are fine. Rule of thumb in the physical layer of voice/data/video: It's never the cable. Sometimes coax can go bad if has been bent in half or somehow the center conductor has been screwed up.. but 98% of the time the cable is never the problem.
     
  6. Rob

    Rob OT Supporter

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    Spoken like a true Layer 1 guy. :big grin:


    I could never understand why they insisted on running new cable to the modem when I had coax that was > 20 years old going from the box to the house. This cable was DEFINATELY not as good of grade as what they just put in.
     
  7. DatacomGuy

    DatacomGuy is moving to Canada

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    :bigok:

    Me neither. Never makes sense...Your bandwidth is only as good as its weakest link. :eek3:
     
  8. Accido

    Accido New Member

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    I thought adding more drops gave you more power for singals? Isn't it also a rule of thumb to have one drop for 4 tvs? I have about six active not including the cable modem itself.
     
  9. DatacomGuy

    DatacomGuy is moving to Canada

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    Technically each outlet is considered a "drop". If you have one outlet in 4 rooms of the house, this would equal 4 drops. If you have one feed from the provider (poll to house), then you have one feed, 4 drops.

    Adding more feeds from the provider will give you more bandwidth or power.. not more drops.

    Depending on the provider, its best to have 2 or less active devices on each drop (single coax). Splitting for digital cable or high speed is considered a :nono:, although possible, doable, and done very very often.
     
  10. Accido

    Accido New Member

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    oh okay, thanks. that's what I wanted him to do: install a third line from the poll to the house, and have the third one directly connected to my cable modem, but he did some stupid bandwidth test and said, "it's at 0 so you should get all the speed you need. it's up to you" He talked me out of if basically. :sad2:
     
  11. DatacomGuy

    DatacomGuy is moving to Canada

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    Lazy bastard.
     
  12. Accido

    Accido New Member

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    hahaha cable guys are here right now making fun of him. :rofl:
     
  13. Accido

    Accido New Member

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    said I had a negative 9 in the cable outlet and normal is supposed to be 0
     
  14. DatacomGuy

    DatacomGuy is moving to Canada

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    Exactly. You had too much loss and drain from other drops.

    Normal is 0 with +/- 1% allowance.
     

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