BT iPlate

Discussion in 'Broadband' started by Woody, Aug 3, 2014.

  1. Woody

    Woody Guest

    I have been helping an elderly neighbour who has just got a
    laptop, and broadband supplied by the Post Office. They
    posted him a Zyxel wireless router complete with two plug-in
    phone line filters and expected him - at 89 - to set it up
    himself, so I did it for him. He has two extension wired
    phones both of which had plug-in filters as well.

    Speedtest using the Warwick University servers showed a ping
    of 36mS and peaking at 7.47Mb/s on a wireless connection.

    I suggested a BT iPlate (actually intended for vDSL but
    backward compatible) having read much about it on line.

    To cut a long story short I ran Speedtest again yesterday,
    same speed 7.47Mb/s but this time with a wired connection. I
    then fitted the iPlate and removed the additional filters as
    well. Left the router to settle for about 15 mins then ran
    Speedtest again on the same server: this time 31mS ping and
    10.69Mb/s download.

    Now I would have believed possibly a minor improvement, but
    over 50%?? Amazing.

    There again as a cable user it might amaze me!
     
    Woody, Aug 3, 2014
    #1
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  2. Woody

    fred Guest

    Not using an iPlate but with a filtered faceplate I have recently
    changed an installation with appalling extension wiring from a
    downstream SNR margin of 6.0 to 13.1. Download speed remains 9.75M down
    but I am hoping for 16M plus after a bit of re-training, otherwise I
    will ask them to reset the profile. The 7dB lift came as a bit of a
    surprise to me too.
     
    fred, Aug 3, 2014
    #2
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  3. Woody

    Woody Guest


    Actually my mistake, this was a fully filtered faceplate
    marked as BT Openreach vDSL Interstitial Faceplate Mk2, not
    just the iPlate.
    The iPlate would not, I think, have made any difference as I
    believe all it does is filter the ringing line which this
    installation does not have.

    I'll get my neighbour to run Speedtest again later this week
    and see if has got any better - between the ADSL dropouts
    that is........
     
    Woody, Aug 3, 2014
    #3
  4. Woody

    Peter Able Guest

    An iPlate does more than isolate the ongoing bell wire. It also
    rebalances the line pair. This can make a slightly unbalanced line
    quieter/more noise-immune from the adsl modem's point of view.

    PA
     
    Peter Able, Aug 4, 2014
    #4
  5. I too would have expected it only to make a difference where the modem
    was on the end of an extension and therefore possibly affected by the
    bell wire. However, if iPlates really do contain superior filters that
    can make a difference, and as they're not very expensive, I think I
    should count this as an experiment I can't afford not to try...

    Rod.
     
    Roderick Stewart, Aug 4, 2014
    #5
  6. Woody

    Woody Guest


    I found it for £5.19 plus 50p p&p - and it arrived in two
    days. Look in Amazon for JLCD Ltd.
     
    Woody, Aug 4, 2014
    #6
  7. Woody

    Peter Able Guest

    It is not a "superior" filter, but it is a DIFFERENT sort of filter
    entirely from the one which is used to split broadband and POTS signals.

    The latter filters by frequency and works because the broadband
    frequencies are different from the POTS frequencies.

    The former tries to remove what are called "common mode" signals from
    the line and to re-balance "differential mode" signals - and works
    because the wanted signals are the transmitted into the line in a
    differential mode whilst the unwanted ones being picked up by the line
    manifest as common-mode signals.

    I could go into more depth - in fact I did, but have cut a lengthy
    exposition that might be too much to take in. Suffice it to say that -
    fortunately - there are several physical characteristics which
    differentiate what is wanted and what isn't wanted. The two sorts of
    filters I've mentioned go to work on different characteristics and so
    can be regarded as complementary means of enhancing the
    wanted-to-unwanted signal ratio.

    PA
     
    Peter Able, Aug 4, 2014
    #7
  8. So it balances the line as well as filtering. Doesn't that make it
    superior?

    On the available testimony (yet to be verified by me, but I'm
    definitely going to give it a try) the use of an iPlate can give a
    faster connection and/or a better SNR, even with ADSL. Doesn't that
    make it superior too?

    We may disagree on exactly what the word "superior" means, but I hope
    we can agree that an iPlate contains a filter which differs in a way
    that makes it work better, whatever word you want to use for that.

    Rod.
     
    Roderick Stewart, Aug 4, 2014
    #8
  9. Woody

    Peter Able Guest

    No, I made it quite clear that the filters discussed are DIFFERENT and
    complementary. Their function(s) do not overlap one jot. Therefore the
    concept of "superior", "better" ( your word - below) - or whatever
    synonym you choose - has no meaning.
    No, we can't agree because you don't seem to realise ("a filter which
    differs in a way that makes it work better") that different filters
    address different issues. As for the two filters I commented upon, if
    the installation has no active bell wiring and the lines are reasonably
    balanced and not subject to much EM induction then the iPlate will not
    help significantly. If the installation has no POTS equipment then a
    splitter filter would be a waste of money.

    I bought an iPlate. As you say, it isn't that expensive. It didn't
    help me, personally, one jot but it has been helpful when I've been
    helping others. More to the point, I understand its engineering
    functions and therefore its relationship to other elements in the
    installation. If you flame my notes, then that attempt to share that
    knowledge has gone down the pan.

    PA
     
    Peter Able, Aug 4, 2014
    #9
  10. Since the input to just about every router ever has a common mode
    balanced input doofus, getting rid of common mode hash is pretty
    irrelevant at the filter plate
     
    The Natural Philosopher, Aug 4, 2014
    #10
  11. Woody

    Peter Able Guest

    I wish that you were right. I've come across several that don't.
    Netgear DG834s actually have the layout on the pcb - but no choke, just
    0R0 resistors.

    There's a second issue, too. I've seen designs with diode clamps at the
    inputs. Differential signals are never going to activate them even if
    you're next to an exchange - but common-mode can - especially if you've
    a radio amateur in the vicinity. The resulting humping of the internal
    supply rails does the modem's operation no good at all.

    FWIW, in the presence of such common-mode mayhem I've found that a
    common-mode choke as close to the modem as possible seems to outperform
    an iPlate / Broadband Accelerator at the Master Socket.

    PA
     
    Peter Able, Aug 4, 2014
    #11
  12. No.
    All it does is rebalance the line.
    As I understand it it doesn't filter at all.

    Filtering is only for the non ADSL equipment.
     
    Brian Gregory, Aug 4, 2014
    #12
  13. Whatever it does, if it works better then it's better. The experience
    of several people here suggests that that's what happens, so I think
    that as it's not very expensive it's worth a try. That has a meaning
    for me, and if it does work better, it'll mean even more.

    Rod.
     
    Roderick Stewart, Aug 4, 2014
    #13
  14. Woody

    Woody Guest

    message
    [snip]
    Remember this is fundamentaly a vDSL filter which is
    backward compatible with ADSL so there may be a bit more to
    it than meets the eye?
     
    Woody, Aug 5, 2014
    #14
  15. The difference between an i-plate and a filtered socket are explained here:
    http://www.increasebroadbandspeed.co.uk/I-Plate-broadband-accelerator-adsl-faceplate

    I had an i-plate a few years ago and it *did* increase my broadband speed.
    However, since then, I had some re-wiring done and the Openreach
    engineer installed a *proper* filtered faceplate in place of the
    i-plate. This increased my speed even more.
     
    George Weston, Aug 5, 2014
    #15
  16. Woody

    Peter Able Guest

    Replace the "explained" with "muddied", George. Just like many other
    iPlate articles - probably all derived from each other - the presence
    and function of the common-mode choke is ignored - and yet all the
    (well, five) iPlates I've ever opened up include a common-mode choke.

    Has anyone got a circuit diagram for the "filtered socket" mentioned in
    the article? I've opened up one of the earlier 1.0A type - which has no
    common functionality with an iPlate - but the later one may.

    PA
     
    Peter Able, Aug 5, 2014
    #16
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