can internal wiring fault cause ADSL failure?

Discussion in 'Broadband' started by davek, Nov 24, 2005.

  1. davek

    davek Guest

    I had a call from BT Wholesale today in relation to my ongoing problem
    with lack of ADSL and it left me a bit confused.

    I have already been told by visiting engineers that I can't have ADSL
    because I am too far from the exchange, but the chap on the phone seemed
    to think that a 512k connection ought to work and that the real problem
    was not line length (he seemed to be denying that line length in itself
    could cause ADSL to fail) but a fault on my internal wiring.

    He told me that the signal quality drops from 600 outside my house to
    400 inside. To quote my old maths teacher: "600 what? 600 Mars bars?"
    I'd be grateful if someone could explain to me what these figures might

    Also, how do they measure them? I don't understand how it can be
    possible to be so precise about where the fault is without actually
    coming round to my house and physically testing the wiring.

    Anyway, the upshot of this is that an engineer will be coming to my
    house tomorrow to attempt to fix the fault and maybe I will be able to
    have broadband after all. But I'm not holding my breath.

    While I had him on the line, I asked a few other questions, and got some
    interesting answers. It seems these figures (the 600 and the 400) have
    been available to them all along, and yet for some reason they did not
    see fit to make use of the information when assessing the suitability of
    my line for ADSL.

    What's even more confusing is that I asked one of the visiting engineers
    very specifically about the possibility of internal wiring being faulty
    and that being the cause of the problem, and he very specifically denied
    it could even be possible.

    Ho hum!

    davek, Nov 24, 2005
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  2. davek

    cw Guest

    Really, every BT engineer we had out during having an annoying fault took
    one look at our master socket and immediately blamed all our extensions for
    causing the problem...until they spoke to me and I told them to look
    closely at the wires for the extension, the *disconnected* wires for the
    extension :0)

    I'm not sure what the figures are though, they are normally quoted in
    decibels but they don't look like that...
    cw, Nov 24, 2005
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  3. davek

    Kraftee Guest

    Line length is a misnomer, it's the construction of the line, the state
    of the line & other external factors which afftects the signal, which is
    why you can have people who live relatively close to their exchanges
    being unable to have ADSL & yet you can get 1Mb connections out as far
    as 7Km on other circuits (came as a shock as I have always been led to
    believe that it's 10dB per Km normally, you learn something new
    Without the labels/context it could mean anything & so are meaningless
    Exactly, push for a home visit, you're internal wiring could be part of
    the problem, but the BT engineer (soon to be Openreach engineer, same
    vans, purple overalls, yuk) should test to your NTE5. If it's succesful
    there then you can make a valued decision about whether you want BT to
    sort out your internal wiring (expensive) or do it yourself, takes a bit
    longer but what the hell you may learn something.
    Make sure he tests your circuit at the NTE with all extensions/burglar
    alarms etc disconnected.
    As I said, figures without labels are meaningless & if they are from
    remote testing, are very often inacurrate.
    Sorry but he is in error, I've known internal wiring to causes excessive
    loop attenuation ( in one case the end user installed extension doubled
    the loop attenuation) and also SNR problems (effectively how clean the
    ADSL signal is), An extension can act as a aeriel picking up any
    RF/electric noise & feed it back into the ADSL signal effectively
    drowning it out.
    Kraftee, Nov 24, 2005
  4. davek

    davek Guest

    So, supposing the state of my line were perfect, along its full length,
    I might even get a 2mb connection? Oh for a perfect world...
    Well, the context is phone lines, which I was hoping would be enough for
    someone to work out what the labels might likely be. But they certainly
    aren't likely to relate to anything from my limited knowledge of the
    Thanks, that's a useful tip - I shall make sure he does that. Even
    though I don't know what one of those is. :)
    The chap who phoned me kept going on about other things being attached
    to the line, suggesting it was probably something like a burglar alarm,
    but as far as I know we don't have anything like that attached to the
    line - we just have the DECT base station and the wireless router
    plugged into the master socket, and a short extension from the master
    socket to a second socket in the kitchen. We don't even have a Sky box,
    which was something else he mentioned, but I don't see why a Sky box
    would cause a problem like that anyway (we had a Sky box at our last
    house and it never affected our connection).

    Could there be some other device on the line that I don't know about?
    The only possible candidate I can think of would be the doorbell, but I
    have looked and I can't see any evidence of a connection there.
    I should have made that clearer - he was denying it was the cause of
    /my/ problem, rather than saying it could never happen, but he came to a
    decision without actually testing anything, as far as I could tell.
    This may be a daft question, but can DECT phones cause a problem? They
    didn't prevent us getting adsl at our last house, but there we were much
    closer to the exchange.

    Thanks for your comments,

    davek, Nov 25, 2005
  5. davek

    davek Guest

    .... but I do know now because I just looked it up. Aha!

    davek, Nov 25, 2005
  6. davek

    Kraftee Guest

    Well it could be volts, ohms, nano farads, etc etc etc.... A number
    without a label is meaningless & because of the values given you can't
    even make an educated guess...
    Socket with a line across the middle, it should be the first socket on
    the line, once it's inside your house/garage/loft, the actual telephone
    socket would be about 3/4 of the way down the faceplate..
    If the equipment is properly filtered it should have little effect, the
    problems are when they are not!

    One thing which hasn't been mentioned yet, have you got a
    external/seperate bell in the circuit (known to cause problems &
    depending on what type it may be virtually impossible to filter)
    See above
    Argh the good old wet finger hold it up in the air & make a random
    diagnosis, wish some of my colleagues would stop doing that & put all
    their efforts into doing what they are paid to do, that is get their
    hands dirty & test the circuits
    If the DECT phones are correctly filtered (& aren't faulty) they should
    give you no problems at all, some of the early Synergy did have problems
    though so it's not unknown.
    Kraftee, Nov 25, 2005
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