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Bradlewis's avatar
Bradlewis
Dialled in
24 days ago
Solved

High power levels affecting connection.

Hi, 

I have recently moved house and below are my current power levels already with a 6db Wideband Attenuator attched, which was left by the previous owner of the house. 

I am having some connection issues now and then along with quite a few daily "DBC-REQ Mismatch " warnings in the hub network log so it seem the 6db might not be enough. 

Please can i request an engineer so this can be looked into :) 

 

Kind regards

 

engineer
Power level
  • Bradlewis's avatar
    Bradlewis
    19 days ago

    Thank you for arranging an engineer to come out. 
    He confirmed the levels were high. Hes replaced the box / internals on the wall where the line comes in as it was old and added a newer 10bd attenuator onto the back of the router. 
    Noise isnt "Perfect" but much better sitting at around 6 - 8db on the downstream for 3.0.... 7db for the 3.1. 
    He advised that is didnt want to push the noise lower as other levels can start to be affected but currently all his tests passed and any further issues to contact again. 

10 Replies

    • Bradlewis's avatar
      Bradlewis
      Dialled in
      24 days ago

      Hi, 
      These are the levels with the 6db attenuator removed

       

       

      • unisoft's avatar
        unisoft
        Super solver
        21 days ago

        You have DocSIS 3.1 channels. You need engineer to fit an Equalizer not the old attenuator (these usually had a pinkish rectangle label stating level of attenuation e.g. 6db).

        The equaliser is needed for DocSIS 3.1 channels as it will attenuate the stronger signals, but not affect the weaker ones used for DocSIS 3.1 channels. It is selective on frequencies whereas the standard attenuator does everything. The engineer will know if your area runs DocSIS 3.1 channels on the weaker spectrum, most areas do. You can't merely go by power levels alone. You'll probably need the equivalent of a 10db equalizer.

    • Bradlewis's avatar
      Bradlewis
      Dialled in
      24 days ago

      My post with snips needs to be approved but the levels increase to around 15 - 17ish with the 6db attenuator removed

      • Carley_S's avatar
        Carley_S
        Icon for Forum Team rankForum Team
        21 days ago

        Hi Bradlewis 

        Welcome to the Community Forums. 

        Sorry to hear of your service concerns. We can see on the systems on our side as well that our downstream power levels are out of specification. This would require an engineer to attend to investigate further. 

        Please join me in a private message so I can locate your account and pass the account security. You can see your private messages at the top of the page, in the envelope icon, or if you're using a smaller device, you can see your private messages by clicking on the Virgin Media logo at the top right and selecting 'Messages' from the drop-down. 

  • Tudor's avatar
    Tudor
    Very Insightful Person
    24 days ago

    We need to see all the upstream channels. You cannot guess how to adjust the downstream without seeing the upstream figures. You may just need moving to another tap on the street cabinet with or without an attenuator or just an attenuator. 

    • Bradlewis's avatar
      Bradlewis
      Dialled in
      24 days ago

      Does this help? Ive just copy and paste as when i attach a snip i have to wait for them to be approved. (this is with the current 6db Attenuator attched) 
      just fyi, im not guessing anything, ive asked for an engineer so hopefully this is something they can help with. Thanks. 

      3.0 Upstream channels
      Channel    Frequency (Hz)    Power (dBmV)    Symbol Rate (ksps)    Modulation    Channel ID
      0    49600000    43    5120    QAM 64    1
      1    43100000    42.5    5120    QAM 64    2
      2    36600000    41.5    5120    QAM 64    3
      3    30100000    41    5120    QAM 64    4
      4    23600000    41    5120    QAM 64    5

      3.0 Upstream channels
      Channel    Channel Type    T1 Timeouts    T2 Timeouts    T3 Timeouts    T4 Timeouts
      0    ATDMA    0    0    1    0
      1    ATDMA    0    0    1    0
      2    ATDMA    0    0    1    0
      3    ATDMA    0    0    1    0
      4    ATDMA    0    0    1    1

      3.1 Upstream channels
      Channel    Channel Width (MHz)    Power (dBmV)    FFT Type    Modulation
      6    10    37.0    2K    QAM 256

      3.1 Upstream channels
      Channel    Channel Type    Number of Active Subcarriers    First Active Subcarrier (Hz)    T3 Timeouts    T4 Timeouts
      6    OFDMA    200    74000000    18    0

      • Tudor's avatar
        Tudor
        Very Insightful Person
        24 days ago

        Those upstreams look good, probably just need a forward path attenuator. Definitely a technician’s visit required.