• Northern line woes

    From boltar@boltar@caprica.universe to uk.transport.london,uk.railway on Thu Oct 23 15:51:37 2025
    From Newsgroup: uk.transport.london

    Sounds like LU need to get some better engineers:

    https://www.bbc.co.uk/news/articles/c0kpxvkjvpno

    Its a radio based signalling system FFS , either the radio signal is there
    and correct at stockwell or it isn't. If it is then trace the data route back towards the main computer until you find the fault component. If it isn't then replace the dodgy tranceivers and/or cabling. This shouldn't take 5 days and counting.

    --- Synchronet 3.21a-Linux NewsLink 1.2
  • From Tweed@usenet.tweed@gmail.com to uk.railway,uk.transport.london on Thu Oct 23 16:07:55 2025
    From Newsgroup: uk.transport.london

    <boltar@caprica.universe> wrote:
    Sounds like LU need to get some better engineers:

    https://www.bbc.co.uk/news/articles/c0kpxvkjvpno

    Its a radio based signalling system FFS , either the radio signal is there and correct at stockwell or it isn't. If it is then trace the data route back
    towards the main computer until you find the fault component. If it isn't then
    replace the dodgy tranceivers and/or cabling. This shouldn't take 5 days and counting.



    Radio based?

    --- Synchronet 3.21a-Linux NewsLink 1.2
  • From Recliner@recliner.usenet@gmail.com to uk.transport.london,uk.railway on Thu Oct 23 16:31:46 2025
    From Newsgroup: uk.transport.london

    Tweed <usenet.tweed@gmail.com> wrote:
    <boltar@caprica.universe> wrote:
    Sounds like LU need to get some better engineers:

    https://www.bbc.co.uk/news/articles/c0kpxvkjvpno

    Its a radio based signalling system FFS , either the radio signal is there >> and correct at stockwell or it isn't. If it is then trace the data route back
    towards the main computer until you find the fault component. If it isn't then
    replace the dodgy tranceivers and/or cabling. This shouldn't take 5 days and
    counting.



    Radio based?

    Very short range. It uses the Thales Seltrac system which uses a regularly looped pair of wires between the rails as seen on the DLR. Basically,
    distances are measured by counting the loops traversed under the train.
    ItrCOs possible that some track debris was blocking the signal, or that the wires had been shifted, so the radio connection was intermittent.

    https://www.railengineer.co.uk/lu-northern-line-goes-cbtc/

    Anyway, itrCOs apparently sorted now.

    --- Synchronet 3.21a-Linux NewsLink 1.2
  • From Coffee@martin.coffee@round-midnight.org.uk to uk.transport.london,uk.railway on Fri Oct 24 11:42:13 2025
    From Newsgroup: uk.transport.london

    On 23/10/2025 16:51, boltar@caprica.universe wrote:
    Sounds like LU need to get some better engineers:

    https://www.bbc.co.uk/news/articles/c0kpxvkjvpno

    Its a radio based signalling system FFS , either the radio signal is there and correct at stockwell or it isn't. If it is then trace the data route back towards the main computer until you find the fault component. If it isn't then
    replace the dodgy tranceivers and/or cabling. This shouldn't take 5 days and counting.


    I don't see how we comment about this until we know what the fault is.
    It is obviously something unusual.

    I suspect the engineers can only examine their equipment when the line
    is closed. I suspect if it's not fixed by Saturday or Sunday they will
    close the line by day to give the engineers longer and better access.

    The system is relatively new and hopefully they will learn from this and understand potential fault conditions better should this happen again.
    --- Synchronet 3.21a-Linux NewsLink 1.2
  • From boltar@boltar@caprica.universe to uk.transport.london,uk.railway on Fri Oct 24 10:59:57 2025
    From Newsgroup: uk.transport.london

    On Fri, 24 Oct 2025 11:42:13 +0100
    Coffee <martin.coffee@round-midnight.org.uk> gabbled:
    On 23/10/2025 16:51, boltar@caprica.universe wrote:
    Sounds like LU need to get some better engineers:

    https://www.bbc.co.uk/news/articles/c0kpxvkjvpno

    Its a radio based signalling system FFS , either the radio signal is there >> and correct at stockwell or it isn't. If it is then trace the data route back

    towards the main computer until you find the fault component. If it isn't >then
    replace the dodgy tranceivers and/or cabling. This shouldn't take 5 days and >> counting.


    I don't see how we comment about this until we know what the fault is.
    It is obviously something unusual.

    I suspect the engineers can only examine their equipment when the line
    is closed. I suspect if it's not fixed by Saturday or Sunday they will >close the line by day to give the engineers longer and better access.

    The system is relatively new and hopefully they will learn from this and >understand potential fault conditions better should this happen again.

    It might be a new install but its not a new system by any means and Thales should have enough diagnostics to figure out what an issue is PDQ. Is it hardware or software, if its hardware where is the fault etc etc. This shouldn't take 5 days.

    --- Synchronet 3.21a-Linux NewsLink 1.2
  • From Clive Page@usenet@page2.eu to uk.transport.london,uk.railway on Fri Oct 24 12:20:10 2025
    From Newsgroup: uk.transport.london

    On 24/10/2025 11:42, Coffee wrote:

    I don't see how we comment about this until we know what the fault is.
    It is obviously something unusual.

    I suspect the engineers can only examine their equipment when the line
    is closed.-a I suspect if it's not fixed by Saturday or Sunday they will close the line by day to give the engineers longer and better access.

    The system is relatively new and hopefully they will learn from this and understand potential fault conditions better should this happen again.

    But this lasted five days. Surely the line was closed over night every
    night (or could have been without much inconvenience to passengers) when
    it should have been possible to do comprehensive tests. I gather that
    it is now fixed, but having such an important line more or less unusable
    for 5 whole days is simply not acceptable.
    --
    Clive Page

    --- Synchronet 3.21a-Linux NewsLink 1.2
  • From Recliner@recliner.usenet@gmail.com to uk.railway,uk.transport.london on Fri Oct 24 11:29:22 2025
    From Newsgroup: uk.transport.london

    Coffee <martin.coffee@round-midnight.org.uk> wrote:
    On 23/10/2025 16:51, boltar@caprica.universe wrote:
    Sounds like LU need to get some better engineers:

    https://www.bbc.co.uk/news/articles/c0kpxvkjvpno

    Its a radio based signalling system FFS , either the radio signal is there >> and correct at stockwell or it isn't. If it is then trace the data route back
    towards the main computer until you find the fault component. If it isn't then
    replace the dodgy tranceivers and/or cabling. This shouldn't take 5 days and >> counting.


    I don't see how we comment about this until we know what the fault is.
    It is obviously something unusual.

    I suspect the engineers can only examine their equipment when the line
    is closed. I suspect if it's not fixed by Saturday or Sunday they will close the line by day to give the engineers longer and better access.

    They said they might cancel the Night Tube service if more access is
    needed.


    The system is relatively new

    ItrCOs been in operation for over a decade, so any teething problems should have been resolved long ago.

    and hopefully they will learn from this and
    understand potential fault conditions better should this happen again.


    The line returned to normal operation yesterday, but they werenrCOt quite
    sure how theyrCOd fixed it! I think itrCOs almost certainly to do with the looped signalling cables between the tracks, which might have been
    disturbed in some way.

    --- Synchronet 3.21a-Linux NewsLink 1.2
  • From Recliner@recliner.usenet@gmail.com to uk.railway,uk.transport.london on Fri Oct 24 11:29:23 2025
    From Newsgroup: uk.transport.london

    <boltar@caprica.universe> wrote:
    On Fri, 24 Oct 2025 11:42:13 +0100
    Coffee <martin.coffee@round-midnight.org.uk> gabbled:
    On 23/10/2025 16:51, boltar@caprica.universe wrote:
    Sounds like LU need to get some better engineers:

    https://www.bbc.co.uk/news/articles/c0kpxvkjvpno

    Its a radio based signalling system FFS , either the radio signal is there >>> and correct at stockwell or it isn't. If it is then trace the data route back

    towards the main computer until you find the fault component. If it isn't >> then
    replace the dodgy tranceivers and/or cabling. This shouldn't take 5 days and
    counting.


    I don't see how we comment about this until we know what the fault is.
    It is obviously something unusual.

    I suspect the engineers can only examine their equipment when the line
    is closed. I suspect if it's not fixed by Saturday or Sunday they will
    close the line by day to give the engineers longer and better access.

    The system is relatively new and hopefully they will learn from this and
    understand potential fault conditions better should this happen again.

    It might be a new install but its not a new system by any means and Thales should have enough diagnostics to figure out what an issue is PDQ. Is it hardware or software, if its hardware where is the fault etc etc. This shouldn't take 5 days.

    ItrCOs almost certainly something to do with the looped signalling cables between the tracks. There might have been some movement in it, or the
    signal might have been intermittently blocked by track debris.

    --- Synchronet 3.21a-Linux NewsLink 1.2
  • From boltar@boltar@caprica.universe to uk.railway,uk.transport.london on Fri Oct 24 14:55:44 2025
    From Newsgroup: uk.transport.london

    On Fri, 24 Oct 2025 11:29:23 GMT
    Recliner <recliner.usenet@gmail.com> gabbled:
    <boltar@caprica.universe> wrote:
    On Fri, 24 Oct 2025 11:42:13 +0100
    Coffee <martin.coffee@round-midnight.org.uk> gabbled:
    On 23/10/2025 16:51, boltar@caprica.universe wrote:
    Sounds like LU need to get some better engineers:

    https://www.bbc.co.uk/news/articles/c0kpxvkjvpno

    Its a radio based signalling system FFS , either the radio signal is there >>>> and correct at stockwell or it isn't. If it is then trace the data route >back

    towards the main computer until you find the fault component. If it isn't >>> then
    replace the dodgy tranceivers and/or cabling. This shouldn't take 5 days >and
    counting.


    I don't see how we comment about this until we know what the fault is.
    It is obviously something unusual.

    I suspect the engineers can only examine their equipment when the line
    is closed. I suspect if it's not fixed by Saturday or Sunday they will >>> close the line by day to give the engineers longer and better access.

    The system is relatively new and hopefully they will learn from this and >>> understand potential fault conditions better should this happen again.

    It might be a new install but its not a new system by any means and Thales >> should have enough diagnostics to figure out what an issue is PDQ. Is it
    hardware or software, if its hardware where is the fault etc etc. This
    shouldn't take 5 days.

    ItrCOs almost certainly something to do with the looped signalling cables >between the tracks. There might have been some movement in it, or the
    signal might have been intermittently blocked by track debris.

    Surely any issue with the cables would have been evident in about 5 mins
    once they had their test equipment on site.

    --- Synchronet 3.21a-Linux NewsLink 1.2
  • From Recliner@recliner.usenet@gmail.com to uk.railway,uk.transport.london on Fri Oct 24 15:55:15 2025
    From Newsgroup: uk.transport.london

    <boltar@caprica.universe> wrote:
    On Fri, 24 Oct 2025 11:29:23 GMT
    Recliner <recliner.usenet@gmail.com> gabbled:
    <boltar@caprica.universe> wrote:
    On Fri, 24 Oct 2025 11:42:13 +0100
    Coffee <martin.coffee@round-midnight.org.uk> gabbled:
    On 23/10/2025 16:51, boltar@caprica.universe wrote:
    Sounds like LU need to get some better engineers:

    https://www.bbc.co.uk/news/articles/c0kpxvkjvpno

    Its a radio based signalling system FFS , either the radio signal is there
    and correct at stockwell or it isn't. If it is then trace the data route >> back

    towards the main computer until you find the fault component. If it isn't >>>> then
    replace the dodgy tranceivers and/or cabling. This shouldn't take 5 days >> and
    counting.


    I don't see how we comment about this until we know what the fault is. >>>> It is obviously something unusual.

    I suspect the engineers can only examine their equipment when the line >>>> is closed. I suspect if it's not fixed by Saturday or Sunday they will >>>> close the line by day to give the engineers longer and better access.

    The system is relatively new and hopefully they will learn from this and >>>> understand potential fault conditions better should this happen again.

    It might be a new install but its not a new system by any means and Thales >>> should have enough diagnostics to figure out what an issue is PDQ. Is it >>> hardware or software, if its hardware where is the fault etc etc. This
    shouldn't take 5 days.

    ItrCOs almost certainly something to do with the looped signalling cables
    between the tracks. There might have been some movement in it, or the
    signal might have been intermittently blocked by track debris.

    Surely any issue with the cables would have been evident in about 5 mins
    once they had their test equipment on site.


    Obviously, it wasnrCOt that simple. The cables would still be transmitting their usual signals, but if the cables were slightly displaced, the
    reception on the trains might have been marginal, hence the intermittent
    nature of the reported fault.

    --- Synchronet 3.21a-Linux NewsLink 1.2
  • From Coffee@martin.coffee@round-midnight.org.uk to uk.transport.london,uk.railway on Fri Oct 24 17:48:33 2025
    From Newsgroup: uk.transport.london

    On 24/10/2025 12:20, Clive Page wrote:
    On 24/10/2025 11:42, Coffee wrote:

    I don't see how we comment about this until we know what the fault is.
    It is obviously something unusual.

    I suspect the engineers can only examine their equipment when the line
    is closed.-a I suspect if it's not fixed by Saturday or Sunday they
    will close the line by day to give the engineers longer and better
    access.

    The system is relatively new and hopefully they will learn from this
    and understand potential fault conditions better should this happen
    again.

    But this lasted five days.-a Surely the line was closed over night every night (or could have been without much inconvenience to passengers) when
    it should have been possible to do comprehensive tests.-a-a I gather that
    it is now fixed, but having such an important line more or less unusable
    for 5 whole days is simply not acceptable.



    But it is only closed for about four, or perhaps five, per night.

    Anyway it is fixed now so hopefully they will reveal what was wrong shortly. --- Synchronet 3.21a-Linux NewsLink 1.2
  • From boltar@boltar@caprica.universe to uk.railway,uk.transport.london on Sat Oct 25 09:00:11 2025
    From Newsgroup: uk.transport.london

    On Fri, 24 Oct 2025 15:55:15 GMT
    Recliner <recliner.usenet@gmail.com> gabbled:
    <boltar@caprica.universe> wrote:
    Surely any issue with the cables would have been evident in about 5 mins
    once they had their test equipment on site.


    Obviously, it wasnrCOt that simple. The cables would still be transmitting >their usual signals, but if the cables were slightly displaced, the
    reception on the trains might have been marginal, hence the intermittent >nature of the reported fault.

    Which should have been obvious with any decent test equipment. Anyway, I suspect the changes of the cables being displaced enough to cause issues is highly unlikely. Probably a hardware fault further upstream.

    --- Synchronet 3.21a-Linux NewsLink 1.2
  • From boltar@boltar@caprica.universe to uk.transport.london,uk.railway on Sat Oct 25 09:01:30 2025
    From Newsgroup: uk.transport.london

    On Fri, 24 Oct 2025 17:48:33 +0100
    Coffee <martin.coffee@round-midnight.org.uk> gabbled:
    On 24/10/2025 12:20, Clive Page wrote:
    On 24/10/2025 11:42, Coffee wrote:
    But this lasted five days.-a Surely the line was closed over night every
    night (or could have been without much inconvenience to passengers) when
    it should have been possible to do comprehensive tests.-a-a I gather that >> it is now fixed, but having such an important line more or less unusable
    for 5 whole days is simply not acceptable.



    But it is only closed for about four, or perhaps five, per night.

    Anyway it is fixed now so hopefully they will reveal what was wrong shortly.

    Unlikely. Bith TfL and Thales will want it all to be forgotten about given
    the inability to diagnose the issue for so long.

    --- Synchronet 3.21a-Linux NewsLink 1.2
  • From Tweed@usenet.tweed@gmail.com to uk.railway,uk.transport.london on Sat Oct 25 11:07:13 2025
    From Newsgroup: uk.transport.london

    <boltar@caprica.universe> wrote:
    On Fri, 24 Oct 2025 15:55:15 GMT
    Recliner <recliner.usenet@gmail.com> gabbled:
    <boltar@caprica.universe> wrote:
    Surely any issue with the cables would have been evident in about 5 mins >>> once they had their test equipment on site.


    Obviously, it wasnrCOt that simple. The cables would still be transmitting >> their usual signals, but if the cables were slightly displaced, the
    reception on the trains might have been marginal, hence the intermittent
    nature of the reported fault.

    Which should have been obvious with any decent test equipment. Anyway, I suspect the changes of the cables being displaced enough to cause issues is highly unlikely. Probably a hardware fault further upstream.


    Have you done any debugging of electronics? Even with the best equipment available a subtle fault can be hard to find, and thatrCOs in the comfort of
    a lab. Gets much harder in a dirty tube tunnel with limited access time.
    The fault is usually blindingly obvious once yourCOve identified it, but getting to that point can be hard.

    --- Synchronet 3.21a-Linux NewsLink 1.2
  • From Recliner@recliner.usenet@gmail.com to uk.railway,uk.transport.london on Sat Oct 25 11:36:33 2025
    From Newsgroup: uk.transport.london

    Tweed <usenet.tweed@gmail.com> wrote:
    <boltar@caprica.universe> wrote:
    On Fri, 24 Oct 2025 15:55:15 GMT
    Recliner <recliner.usenet@gmail.com> gabbled:
    <boltar@caprica.universe> wrote:
    Surely any issue with the cables would have been evident in about 5 mins >>>> once they had their test equipment on site.


    Obviously, it wasnrCOt that simple. The cables would still be transmitting >>> their usual signals, but if the cables were slightly displaced, the
    reception on the trains might have been marginal, hence the intermittent >>> nature of the reported fault.

    Which should have been obvious with any decent test equipment. Anyway, I
    suspect the changes of the cables being displaced enough to cause issues is >> highly unlikely. Probably a hardware fault further upstream.


    Have you done any debugging of electronics? Even with the best equipment available a subtle fault can be hard to find, and thatrCOs in the comfort of a lab. Gets much harder in a dirty tube tunnel with limited access time.
    The fault is usually blindingly obvious once yourCOve identified it, but getting to that point can be hard.


    In this case, they apparently fixed it without quite knowing what theyrCOd done. Of course, if the fault has (temporarily?) disappeared, that makes it even harder to positively identify and permanently fix it.

    --- Synchronet 3.21a-Linux NewsLink 1.2
  • From Tweed@usenet.tweed@gmail.com to uk.railway,uk.transport.london on Sat Oct 25 11:53:39 2025
    From Newsgroup: uk.transport.london

    Recliner <recliner.usenet@gmail.com> wrote:
    Tweed <usenet.tweed@gmail.com> wrote:
    <boltar@caprica.universe> wrote:
    On Fri, 24 Oct 2025 15:55:15 GMT
    Recliner <recliner.usenet@gmail.com> gabbled:
    <boltar@caprica.universe> wrote:
    Surely any issue with the cables would have been evident in about 5 mins >>>>> once they had their test equipment on site.


    Obviously, it wasnrCOt that simple. The cables would still be transmitting >>>> their usual signals, but if the cables were slightly displaced, the
    reception on the trains might have been marginal, hence the intermittent >>>> nature of the reported fault.

    Which should have been obvious with any decent test equipment. Anyway, I >>> suspect the changes of the cables being displaced enough to cause issues is >>> highly unlikely. Probably a hardware fault further upstream.


    Have you done any debugging of electronics? Even with the best equipment
    available a subtle fault can be hard to find, and thatrCOs in the comfort of >> a lab. Gets much harder in a dirty tube tunnel with limited access time.
    The fault is usually blindingly obvious once yourCOve identified it, but
    getting to that point can be hard.


    In this case, they apparently fixed it without quite knowing what theyrCOd done. Of course, if the fault has (temporarily?) disappeared, that makes it even harder to positively identify and permanently fix it.



    IrCOd hazard a guess that it was a marginally faulty connector. Disturbing
    the wiring has remade the connection, at least for the time being. Tracing
    a fault that has gone away is even harder.

    --- Synchronet 3.21a-Linux NewsLink 1.2
  • From boltar@boltar@caprica.universe to uk.railway,uk.transport.london on Sat Oct 25 14:40:23 2025
    From Newsgroup: uk.transport.london

    On Sat, 25 Oct 2025 11:07:13 -0000 (UTC)
    Tweed <usenet.tweed@gmail.com> gabbled:
    <boltar@caprica.universe> wrote:
    On Fri, 24 Oct 2025 15:55:15 GMT
    Recliner <recliner.usenet@gmail.com> gabbled:
    <boltar@caprica.universe> wrote:
    Surely any issue with the cables would have been evident in about 5 mins >>>> once they had their test equipment on site.


    Obviously, it wasnrCOt that simple. The cables would still be transmitting >>> their usual signals, but if the cables were slightly displaced, the
    reception on the trains might have been marginal, hence the intermittent >>> nature of the reported fault.

    Which should have been obvious with any decent test equipment. Anyway, I
    suspect the changes of the cables being displaced enough to cause issues is >> highly unlikely. Probably a hardware fault further upstream.


    Have you done any debugging of electronics? Even with the best equipment >available a subtle fault can be hard to find, and thatrCOs in the comfort of >a lab. Gets much harder in a dirty tube tunnel with limited access time.
    The fault is usually blindingly obvious once yourCOve identified it, but >getting to that point can be hard.

    Why would you need to debug anything? Its like modern car maintenance - if
    a black box isn't working change it. You don't take the lid off and get
    the soldering iron out.

    --- Synchronet 3.21a-Linux NewsLink 1.2
  • From boltar@boltar@caprica.universe to uk.railway,uk.transport.london on Sat Oct 25 14:41:38 2025
    From Newsgroup: uk.transport.london

    On Sat, 25 Oct 2025 11:53:39 -0000 (UTC)
    Tweed <usenet.tweed@gmail.com> gabbled:
    Recliner <recliner.usenet@gmail.com> wrote:
    In this case, they apparently fixed it without quite knowing what theyrCOd >> done. Of course, if the fault has (temporarily?) disappeared, that makes it >> even harder to positively identify and permanently fix it.



    IrCOd hazard a guess that it was a marginally faulty connector. Disturbing >the wiring has remade the connection, at least for the time being. Tracing
    a fault that has gone away is even harder.

    I highly doubt a single faulty connector would take out an entire section of the line.

    --- Synchronet 3.21a-Linux NewsLink 1.2
  • From Tweed@usenet.tweed@gmail.com to uk.railway,uk.transport.london on Sat Oct 25 15:13:17 2025
    From Newsgroup: uk.transport.london

    <boltar@caprica.universe> wrote:
    On Sat, 25 Oct 2025 11:07:13 -0000 (UTC)
    Tweed <usenet.tweed@gmail.com> gabbled:
    <boltar@caprica.universe> wrote:
    On Fri, 24 Oct 2025 15:55:15 GMT
    Recliner <recliner.usenet@gmail.com> gabbled:
    <boltar@caprica.universe> wrote:
    Surely any issue with the cables would have been evident in about 5 mins >>>>> once they had their test equipment on site.


    Obviously, it wasnrCOt that simple. The cables would still be transmitting >>>> their usual signals, but if the cables were slightly displaced, the
    reception on the trains might have been marginal, hence the intermittent >>>> nature of the reported fault.

    Which should have been obvious with any decent test equipment. Anyway, I >>> suspect the changes of the cables being displaced enough to cause issues is >>> highly unlikely. Probably a hardware fault further upstream.


    Have you done any debugging of electronics? Even with the best equipment
    available a subtle fault can be hard to find, and thatrCOs in the comfort of >> a lab. Gets much harder in a dirty tube tunnel with limited access time.
    The fault is usually blindingly obvious once yourCOve identified it, but
    getting to that point can be hard.

    Why would you need to debug anything? Its like modern car maintenance - if
    a black box isn't working change it. You don't take the lid off and get
    the soldering iron out.


    And when each black box when tested works just fine, but when assembled
    into a system things donrCOt work as expected? And when you substitute black boxes and still have the same fault?

    I spent a day or two debugging a transmitter fault. Worked fine up in the
    lab plugged into a dummy load. Took it downstairs to the container where it
    was due to operate. WouldnrCOt work. Measured container dummy load, fine. Tested load and coax cable into expensive test gear. Measured correctly.
    Took transmitter back up to lab. Worked. Took it downstairs and plugged
    into aforementioned tested load and cable, tripped. Only conclusion was
    that the fault was altitude dependentrCa..

    Actual fault was RF connector on the dummy load cable was slightly out of
    spec. It didnrCOt mate properly with the transmitterrCOs connector, but did mate with the test instrumentrCOs connector. Silly fault, but took ages to track down. All black boxes worked individually but not together.

    --- Synchronet 3.21a-Linux NewsLink 1.2
  • From boltar@boltar@caprica.universe to uk.railway,uk.transport.london on Sat Oct 25 15:20:28 2025
    From Newsgroup: uk.transport.london

    On Sat, 25 Oct 2025 15:13:17 -0000 (UTC)
    Tweed <usenet.tweed@gmail.com> gabbled:
    <boltar@caprica.universe> wrote:
    Why would you need to debug anything? Its like modern car maintenance - if >> a black box isn't working change it. You don't take the lid off and get
    the soldering iron out.


    And when each black box when tested works just fine, but when assembled
    into a system things donrCOt work as expected? And when you substitute black >boxes and still have the same fault?

    Then its not the boxes.

    Actual fault was RF connector on the dummy load cable was slightly out of >spec. It didnrCOt mate properly with the transmitterrCOs connector, but did >mate with the test instrumentrCOs connector. Silly fault, but took ages to >track down. All black boxes worked individually but not together.

    So trying some different cables never occured to you? Ok....

    --- Synchronet 3.21a-Linux NewsLink 1.2
  • From Tweed@usenet.tweed@gmail.com to uk.railway,uk.transport.london on Sat Oct 25 15:27:19 2025
    From Newsgroup: uk.transport.london

    <boltar@caprica.universe> wrote:
    On Sat, 25 Oct 2025 11:53:39 -0000 (UTC)
    Tweed <usenet.tweed@gmail.com> gabbled:
    Recliner <recliner.usenet@gmail.com> wrote:
    In this case, they apparently fixed it without quite knowing what theyrCOd >>> done. Of course, if the fault has (temporarily?) disappeared, that makes it >>> even harder to positively identify and permanently fix it.



    IrCOd hazard a guess that it was a marginally faulty connector. Disturbing >> the wiring has remade the connection, at least for the time being. Tracing >> a fault that has gone away is even harder.

    I highly doubt a single faulty connector would take out an entire section of the line.



    Why not? Unless the system is designed with hot redundancy (unlikely) that
    one connector has a purpose. If it doesnrCOt work that functionality stops. Even worse if that connector is making intermittent contact, perhaps disconnecting in the presence of a train. As manufacturers discovered after
    the Covid supply chain disruptions, securing supply of all the fancy
    components wasnrCOt enough. Without the boring bits as well, such as a regulator chip or a usb interface chip, you couldnrCOt manufacture a working board.

    --- Synchronet 3.21a-Linux NewsLink 1.2
  • From Tweed@usenet.tweed@gmail.com to uk.railway,uk.transport.london on Sat Oct 25 15:32:58 2025
    From Newsgroup: uk.transport.london

    <boltar@caprica.universe> wrote:
    On Sat, 25 Oct 2025 15:13:17 -0000 (UTC)
    Tweed <usenet.tweed@gmail.com> gabbled:
    <boltar@caprica.universe> wrote:
    Why would you need to debug anything? Its like modern car maintenance - if >>> a black box isn't working change it. You don't take the lid off and get
    the soldering iron out.


    And when each black box when tested works just fine, but when assembled
    into a system things donrCOt work as expected? And when you substitute black >> boxes and still have the same fault?

    Then its not the boxes.

    Actual fault was RF connector on the dummy load cable was slightly out of
    spec. It didnrCOt mate properly with the transmitterrCOs connector, but did >> mate with the test instrumentrCOs connector. Silly fault, but took ages to >> track down. All black boxes worked individually but not together.

    So trying some different cables never occured to you? Ok....


    When a -u30k vector network analyser (you are the one saying test gear
    should be used) tells you the cable and load are fine it takes a while to conclude that the cable isnrCOt fine.

    --- Synchronet 3.21a-Linux NewsLink 1.2
  • From Recliner@recliner.usenet@gmail.com to uk.railway,uk.transport.london on Sat Oct 25 15:48:12 2025
    From Newsgroup: uk.transport.london

    <boltar@caprica.universe> wrote:
    On Sat, 25 Oct 2025 11:53:39 -0000 (UTC)
    Tweed <usenet.tweed@gmail.com> gabbled:
    Recliner <recliner.usenet@gmail.com> wrote:
    In this case, they apparently fixed it without quite knowing what theyrCOd >>> done. Of course, if the fault has (temporarily?) disappeared, that makes it >>> even harder to positively identify and permanently fix it.



    IrCOd hazard a guess that it was a marginally faulty connector. Disturbing >> the wiring has remade the connection, at least for the time being. Tracing >> a fault that has gone away is even harder.

    I highly doubt a single faulty connector would take out an entire section of the line.

    ItrCOs clear that there was interference in the radio signals from the pair
    of cables in the four foot in one tunnel just north of Stockwell. The train calculates its position by counting the phase changes every 25m, when the
    wires cross over. If it briefly loses the signal, it canrCOt be sure if itrCOs missed any phase changes, and therefore the accuracy of its location, and
    the fail-safe brakes are automatically applied. What we donrCOt know is
    whether the problem was in the cable connectors, the cables themselves or something interfering with the radiated signals.

    --- Synchronet 3.21a-Linux NewsLink 1.2
  • From boltar@boltar@caprica.universe to uk.railway,uk.transport.london on Sat Oct 25 15:49:00 2025
    From Newsgroup: uk.transport.london

    On Sat, 25 Oct 2025 15:27:19 -0000 (UTC)
    Tweed <usenet.tweed@gmail.com> gabbled:
    <boltar@caprica.universe> wrote:
    On Sat, 25 Oct 2025 11:53:39 -0000 (UTC)
    Tweed <usenet.tweed@gmail.com> gabbled:
    Recliner <recliner.usenet@gmail.com> wrote:
    In this case, they apparently fixed it without quite knowing what theyrCOd >>>> done. Of course, if the fault has (temporarily?) disappeared, that makes it

    even harder to positively identify and permanently fix it.



    IrCOd hazard a guess that it was a marginally faulty connector. Disturbing >>> the wiring has remade the connection, at least for the time being. Tracing >>> a fault that has gone away is even harder.

    I highly doubt a single faulty connector would take out an entire section of

    the line.



    Why not? Unless the system is designed with hot redundancy (unlikely) that

    I would bloody well hope a safety critical system like ATO has redundancy!


    --- Synchronet 3.21a-Linux NewsLink 1.2
  • From boltar@boltar@caprica.universe to uk.railway,uk.transport.london on Sat Oct 25 15:50:07 2025
    From Newsgroup: uk.transport.london

    On Sat, 25 Oct 2025 15:32:58 -0000 (UTC)
    Tweed <usenet.tweed@gmail.com> gabbled:
    <boltar@caprica.universe> wrote:
    On Sat, 25 Oct 2025 15:13:17 -0000 (UTC)
    Tweed <usenet.tweed@gmail.com> gabbled:
    <boltar@caprica.universe> wrote:
    Why would you need to debug anything? Its like modern car maintenance - if >>>> a black box isn't working change it. You don't take the lid off and get >>>> the soldering iron out.


    And when each black box when tested works just fine, but when assembled
    into a system things donrCOt work as expected? And when you substitute black

    boxes and still have the same fault?

    Then its not the boxes.

    Actual fault was RF connector on the dummy load cable was slightly out of >>> spec. It didnrCOt mate properly with the transmitterrCOs connector, but did >>> mate with the test instrumentrCOs connector. Silly fault, but took ages to >>> track down. All black boxes worked individually but not together.

    So trying some different cables never occured to you? Ok....


    When a -u30k vector network analyser (you are the one saying test gear
    should be used) tells you the cable and load are fine it takes a while to >conclude that the cable isnrCOt fine.

    Kind of an obvious thing to do I would have thought. When I was having
    issue with my Mac talking to the TV I didn't try and debug the Mac, I changed the HDMI cable. Problem solved.

    --- Synchronet 3.21a-Linux NewsLink 1.2
  • From Tweed@usenet.tweed@gmail.com to uk.railway,uk.transport.london on Sat Oct 25 16:13:50 2025
    From Newsgroup: uk.transport.london

    <boltar@caprica.universe> wrote:
    On Sat, 25 Oct 2025 15:27:19 -0000 (UTC)
    Tweed <usenet.tweed@gmail.com> gabbled:
    <boltar@caprica.universe> wrote:
    On Sat, 25 Oct 2025 11:53:39 -0000 (UTC)
    Tweed <usenet.tweed@gmail.com> gabbled:
    Recliner <recliner.usenet@gmail.com> wrote:
    In this case, they apparently fixed it without quite knowing what theyrCOd
    done. Of course, if the fault has (temporarily?) disappeared, that makes it

    even harder to positively identify and permanently fix it.



    IrCOd hazard a guess that it was a marginally faulty connector. Disturbing >>>> the wiring has remade the connection, at least for the time being. Tracing >>>> a fault that has gone away is even harder.

    I highly doubt a single faulty connector would take out an entire section of

    the line.



    Why not? Unless the system is designed with hot redundancy (unlikely) that

    I would bloody well hope a safety critical system like ATO has redundancy!


    Safety critical systems donrCOt necessarily need redundancy. You can design them to fail safe. Safe may not necessarily mean convenient.

    --- Synchronet 3.21a-Linux NewsLink 1.2
  • From Tweed@usenet.tweed@gmail.com to uk.railway,uk.transport.london on Sat Oct 25 16:17:45 2025
    From Newsgroup: uk.transport.london

    <boltar@caprica.universe> wrote:
    On Sat, 25 Oct 2025 15:32:58 -0000 (UTC)
    Tweed <usenet.tweed@gmail.com> gabbled:
    <boltar@caprica.universe> wrote:
    On Sat, 25 Oct 2025 15:13:17 -0000 (UTC)
    Tweed <usenet.tweed@gmail.com> gabbled:
    <boltar@caprica.universe> wrote:
    Why would you need to debug anything? Its like modern car maintenance - if
    a black box isn't working change it. You don't take the lid off and get >>>>> the soldering iron out.


    And when each black box when tested works just fine, but when assembled >>>> into a system things donrCOt work as expected? And when you substitute black

    boxes and still have the same fault?

    Then its not the boxes.

    Actual fault was RF connector on the dummy load cable was slightly out of >>>> spec. It didnrCOt mate properly with the transmitterrCOs connector, but did
    mate with the test instrumentrCOs connector. Silly fault, but took ages to >>>> track down. All black boxes worked individually but not together.

    So trying some different cables never occured to you? Ok....


    When a -u30k vector network analyser (you are the one saying test gear
    should be used) tells you the cable and load are fine it takes a while to
    conclude that the cable isnrCOt fine.

    Kind of an obvious thing to do I would have thought. When I was having
    issue with my Mac talking to the TV I didn't try and debug the Mac, I changed the HDMI cable. Problem solved.

    Difficult when the transmitter to load cable is not a commodity item. This,
    and railway signalling systems, are not built using consumer grade items.

    --- Synchronet 3.21a-Linux NewsLink 1.2
  • From Recliner@recliner.usenet@gmail.com to uk.railway,uk.transport.london on Sat Oct 25 16:30:05 2025
    From Newsgroup: uk.transport.london

    <boltar@caprica.universe> wrote:
    On Sat, 25 Oct 2025 15:27:19 -0000 (UTC)
    Tweed <usenet.tweed@gmail.com> gabbled:
    <boltar@caprica.universe> wrote:
    On Sat, 25 Oct 2025 11:53:39 -0000 (UTC)
    Tweed <usenet.tweed@gmail.com> gabbled:
    Recliner <recliner.usenet@gmail.com> wrote:
    In this case, they apparently fixed it without quite knowing what theyrCOd
    done. Of course, if the fault has (temporarily?) disappeared, that makes it

    even harder to positively identify and permanently fix it.



    IrCOd hazard a guess that it was a marginally faulty connector. Disturbing >>>> the wiring has remade the connection, at least for the time being. Tracing >>>> a fault that has gone away is even harder.

    I highly doubt a single faulty connector would take out an entire section of

    the line.



    Why not? Unless the system is designed with hot redundancy (unlikely) that

    I would bloody well hope a safety critical system like ATO has redundancy!

    Yes, the computers are duplicated, but thererCOs only one radio signal. If thatrCOs lost, the train stops.

    --- Synchronet 3.21a-Linux NewsLink 1.2
  • From boltar@boltar@caprica.universe to uk.railway,uk.transport.london on Sun Oct 26 09:39:05 2025
    From Newsgroup: uk.transport.london

    On Sat, 25 Oct 2025 15:48:12 GMT
    Recliner <recliner.usenet@gmail.com> gabbled:
    <boltar@caprica.universe> wrote:
    I highly doubt a single faulty connector would take out an entire section of

    the line.

    ItrCOs clear that there was interference in the radio signals from the pair >of cables in the four foot in one tunnel just north of Stockwell. The train

    Well yes, otherwise there wouldn't be an issue. What they clearly didn't know and possibly still don't is what part of the chain cause the problems with
    the signal.

    the fail-safe brakes are automatically applied. What we donrCOt know is >whether the problem was in the cable connectors, the cables themselves or >something interfering with the radiated signals.

    It could have been in whatever box the cables were ultimately wired in to in
    a cabinet somewhere.

    --- Synchronet 3.21a-Linux NewsLink 1.2
  • From boltar@boltar@caprica.universe to uk.railway,uk.transport.london on Sun Oct 26 09:41:41 2025
    From Newsgroup: uk.transport.london

    On Sat, 25 Oct 2025 16:17:45 -0000 (UTC)
    Tweed <usenet.tweed@gmail.com> gabbled:
    <boltar@caprica.universe> wrote:
    Difficult when the transmitter to load cable is not a commodity item. This, >and railway signalling systems, are not built using consumer grade items.

    One would hope they might have the odd spare knocking about. These arn't
    100KV transmission cables 3 inches thick , they're about the same dimensions
    as a 240V mains lead so should be quite simple to carry around.

    --- Synchronet 3.21a-Linux NewsLink 1.2
  • From Certes@Certes@example.org to uk.railway,uk.transport.london on Sun Oct 26 10:24:06 2025
    From Newsgroup: uk.transport.london

    On 26/10/2025 09:41, boltar@caprica.universe wrote:
    On Sat, 25 Oct 2025 16:17:45 -0000 (UTC)
    Tweed <usenet.tweed@gmail.com> gabbled:
    <boltar@caprica.universe> wrote:
    Difficult when the transmitter to load cable is not a commodity item. This, >> and railway signalling systems, are not built using consumer grade items.

    One would hope they might have the odd spare knocking about. These arn't 100KV transmission cables 3 inches thick , they're about the same dimensions as a 240V mains lead so should be quite simple to carry around.

    It might be instructive to insert a -u5 consumer-grade wire as a
    temporary replacement and see what happens. If the system suddenly
    starts working then it's time to order an approved gold-plated cable.

    --- Synchronet 3.21a-Linux NewsLink 1.2
  • From Tweed@usenet.tweed@gmail.com to uk.railway,uk.transport.london on Sun Oct 26 10:36:22 2025
    From Newsgroup: uk.transport.london

    Certes <Certes@example.org> wrote:
    On 26/10/2025 09:41, boltar@caprica.universe wrote:
    On Sat, 25 Oct 2025 16:17:45 -0000 (UTC)
    Tweed <usenet.tweed@gmail.com> gabbled:
    <boltar@caprica.universe> wrote:
    Difficult when the transmitter to load cable is not a commodity item. This, >>> and railway signalling systems, are not built using consumer grade items. >>
    One would hope they might have the odd spare knocking about. These arn't
    100KV transmission cables 3 inches thick , they're about the same dimensions >> as a 240V mains lead so should be quite simple to carry around.

    It might be instructive to insert a -u5 consumer-grade wire as a
    temporary replacement and see what happens. If the system suddenly
    starts working then it's time to order an approved gold-plated cable.



    What consumer grade cable? The connectors will likely be different, the
    number and type of conductors etc. ThererCOs a whole world of cables and connectors outside of that commonly seen in the consumer area.

    --- Synchronet 3.21a-Linux NewsLink 1.2
  • From Recliner@recliner.usenet@gmail.com to uk.railway,uk.transport.london on Sun Oct 26 11:34:48 2025
    From Newsgroup: uk.transport.london

    Certes <Certes@example.org> wrote:
    On 26/10/2025 09:41, boltar@caprica.universe wrote:
    On Sat, 25 Oct 2025 16:17:45 -0000 (UTC)
    Tweed <usenet.tweed@gmail.com> gabbled:
    <boltar@caprica.universe> wrote:
    Difficult when the transmitter to load cable is not a commodity item. This, >>> and railway signalling systems, are not built using consumer grade items. >>
    One would hope they might have the odd spare knocking about. These arn't
    100KV transmission cables 3 inches thick , they're about the same dimensions >> as a 240V mains lead so should be quite simple to carry around.

    It might be instructive to insert a -u5 consumer-grade wire as a
    temporary replacement and see what happens. If the system suddenly
    starts working then it's time to order an approved gold-plated cable.

    This isnrCOt just a routine cable. ItrCOs one of a pair of antenna wires in the four foot (on either side of the negative rail) that radiate a 56kV signal.
    The wires cross over every 25m, and passing trains detect and count the
    phase changes.

    They use their own odometers to measure distances between these null
    points, so even if a point is missed, they still know roughly where they
    are, to within a few metres. Apparently it is permissible to miss one phase change, but the train must report it to the central computer. Another miss
    is considered a failure.

    --- Synchronet 3.21a-Linux NewsLink 1.2
  • From Recliner@recliner.usenet@gmail.com to uk.railway,uk.transport.london on Sun Oct 26 11:34:50 2025
    From Newsgroup: uk.transport.london

    Tweed <usenet.tweed@gmail.com> wrote:
    Certes <Certes@example.org> wrote:
    On 26/10/2025 09:41, boltar@caprica.universe wrote:
    On Sat, 25 Oct 2025 16:17:45 -0000 (UTC)
    Tweed <usenet.tweed@gmail.com> gabbled:
    <boltar@caprica.universe> wrote:
    Difficult when the transmitter to load cable is not a commodity item. This,
    and railway signalling systems, are not built using consumer grade items. >>>
    One would hope they might have the odd spare knocking about. These arn't >>> 100KV transmission cables 3 inches thick , they're about the same dimensions
    as a 240V mains lead so should be quite simple to carry around.

    It might be instructive to insert a -u5 consumer-grade wire as a
    temporary replacement and see what happens. If the system suddenly
    starts working then it's time to order an approved gold-plated cable.



    What consumer grade cable? The connectors will likely be different, the number and type of conductors etc. ThererCOs a whole world of cables and connectors outside of that commonly seen in the consumer area.


    And as the individual wires form a paired antenna, it would presumably
    require both wires to be replaced and anchored in the right physical
    layout. I donrCOt think yourCOd want to do all that just as an experiment. You might well want to replace a stretch of the wires, but on a permanent
    basis, once you know where the fault is.

    --- Synchronet 3.21a-Linux NewsLink 1.2
  • From Tweed@usenet.tweed@gmail.com to uk.railway,uk.transport.london on Sun Oct 26 11:53:07 2025
    From Newsgroup: uk.transport.london

    Recliner <recliner.usenet@gmail.com> wrote:
    Certes <Certes@example.org> wrote:
    On 26/10/2025 09:41, boltar@caprica.universe wrote:
    On Sat, 25 Oct 2025 16:17:45 -0000 (UTC)
    Tweed <usenet.tweed@gmail.com> gabbled:
    <boltar@caprica.universe> wrote:
    Difficult when the transmitter to load cable is not a commodity item. This,
    and railway signalling systems, are not built using consumer grade items. >>>
    One would hope they might have the odd spare knocking about. These arn't >>> 100KV transmission cables 3 inches thick , they're about the same dimensions
    as a 240V mains lead so should be quite simple to carry around.

    It might be instructive to insert a -u5 consumer-grade wire as a
    temporary replacement and see what happens. If the system suddenly
    starts working then it's time to order an approved gold-plated cable.

    This isnrCOt just a routine cable. ItrCOs one of a pair of antenna wires in the
    four foot (on either side of the negative rail) that radiate a 56kV signal. The wires cross over every 25m, and passing trains detect and count the
    phase changes.

    They use their own odometers to measure distances between these null
    points, so even if a point is missed, they still know roughly where they
    are, to within a few metres. Apparently it is permissible to miss one phase change, but the train must report it to the central computer. Another miss
    is considered a failure.



    Did you mean kHz rather than kV?

    --- Synchronet 3.21a-Linux NewsLink 1.2
  • From Recliner@recliner.usenet@gmail.com to uk.railway,uk.transport.london on Sun Oct 26 12:08:55 2025
    From Newsgroup: uk.transport.london

    Tweed <usenet.tweed@gmail.com> wrote:
    Recliner <recliner.usenet@gmail.com> wrote:
    Certes <Certes@example.org> wrote:
    On 26/10/2025 09:41, boltar@caprica.universe wrote:
    On Sat, 25 Oct 2025 16:17:45 -0000 (UTC)
    Tweed <usenet.tweed@gmail.com> gabbled:
    <boltar@caprica.universe> wrote:
    Difficult when the transmitter to load cable is not a commodity item. This,
    and railway signalling systems, are not built using consumer grade items. >>>>
    One would hope they might have the odd spare knocking about. These arn't >>>> 100KV transmission cables 3 inches thick , they're about the same dimensions
    as a 240V mains lead so should be quite simple to carry around.

    It might be instructive to insert a -u5 consumer-grade wire as a
    temporary replacement and see what happens. If the system suddenly
    starts working then it's time to order an approved gold-plated cable.

    This isnrCOt just a routine cable. ItrCOs one of a pair of antenna wires in the
    four foot (on either side of the negative rail) that radiate a 56kV signal. >> The wires cross over every 25m, and passing trains detect and count the
    phase changes.

    They use their own odometers to measure distances between these null
    points, so even if a point is missed, they still know roughly where they
    are, to within a few metres. Apparently it is permissible to miss one phase >> change, but the train must report it to the central computer. Another miss >> is considered a failure.



    Did you mean kHz rather than kV?

    Yes, sorry, my typo. I was thinking of the voltage on the power rails in
    the vicinity, and accidentally typed V rather than Hz.

    --- Synchronet 3.21a-Linux NewsLink 1.2
  • From Marland@gemehabal@btinternet.co.uk to uk.transport.london,uk.railway on Sun Oct 26 19:33:08 2025
    From Newsgroup: uk.transport.london

    Certes <Certes@example.org> wrote:
    On 26/10/2025 09:41, boltar@caprica.universe wrote:
    On Sat, 25 Oct 2025 16:17:45 -0000 (UTC)
    Tweed <usenet.tweed@gmail.com> gabbled:
    <boltar@caprica.universe> wrote:
    Difficult when the transmitter to load cable is not a commodity item. This, >>> and railway signalling systems, are not built using consumer grade items. >>
    One would hope they might have the odd spare knocking about. These arn't
    100KV transmission cables 3 inches thick , they're about the same dimensions >> as a 240V mains lead so should be quite simple to carry around.

    It might be instructive to insert a -u5 consumer-grade wire as a
    temporary replacement and see what happens. If the system suddenly
    starts working then it's time to order an approved gold-plated cable.


    Russ Andrews probably has something.

    <https://www.russandrews.com>

    GH


    --- Synchronet 3.21a-Linux NewsLink 1.2
  • From boltar@boltar@battlestar-galactica.com to uk.railway,uk.transport.london on Sun Oct 26 19:34:17 2025
    From Newsgroup: uk.transport.london

    On Sun, 26 Oct 2025 11:34:48 GMT
    Recliner <recliner.usenet@gmail.com> wrote:
    Certes <Certes@example.org> wrote:
    It might be instructive to insert a -u5 consumer-grade wire as a
    temporary replacement and see what happens. If the system suddenly
    starts working then it's time to order an approved gold-plated cable.

    This isnrCOt just a routine cable. ItrCOs one of a pair of antenna wires in the

    four foot (on either side of the negative rail) that radiate a 56kV signal.

    56Khz presumably?

    The wires cross over every 25m, and passing trains detect and count the
    phase changes.

    Odd choice to use phase given there'll be points where the signals from 2 cables will cancel plus its more complicated to detect phase changes. Why
    on earth didn't they just use 2 seperate frequencies?


    --- Synchronet 3.21a-Linux NewsLink 1.2
  • From Recliner@recliner.usenet@gmail.com to uk.transport.london,uk.railway on Sun Oct 26 21:25:07 2025
    From Newsgroup: uk.transport.london

    <boltar@battlestar-galactica.com> wrote:
    On Sun, 26 Oct 2025 11:34:48 GMT
    Recliner <recliner.usenet@gmail.com> wrote:
    Certes <Certes@example.org> wrote:
    It might be instructive to insert a -u5 consumer-grade wire as a
    temporary replacement and see what happens. If the system suddenly
    starts working then it's time to order an approved gold-plated cable.

    This isnrCOt just a routine cable. ItrCOs one of a pair of antenna wires in the

    four foot (on either side of the negative rail) that radiate a 56kV signal.

    56Khz presumably?

    Yes, sorry, my typo.


    The wires cross over every 25m, and passing trains detect and count the
    phase changes.

    Odd choice to use phase given there'll be points where the signals from 2 cables will cancel plus its more complicated to detect phase changes. Why
    on earth didn't they just use 2 seperate frequencies?

    The crossing points are called null points, for precisely that reason.

    How would using two frequencies work?



    --- Synchronet 3.21a-Linux NewsLink 1.2
  • From boltar@boltar@battlestar-galactica.com to uk.transport.london,uk.railway on Mon Oct 27 19:56:17 2025
    From Newsgroup: uk.transport.london

    On Sun, 26 Oct 2025 21:25:07 GMT
    Recliner <recliner.usenet@gmail.com> wrote:
    <boltar@battlestar-galactica.com> wrote:
    Odd choice to use phase given there'll be points where the signals from 2
    cables will cancel plus its more complicated to detect phase changes. Why
    on earth didn't they just use 2 seperate frequencies?

    The crossing points are called null points, for precisely that reason.

    How would using two frequencies work?

    Is this is a trick question?


    --- Synchronet 3.21a-Linux NewsLink 1.2
  • From Recliner@recliner.usenet@gmail.com to uk.transport.london,uk.railway on Mon Oct 27 22:35:00 2025
    From Newsgroup: uk.transport.london

    <boltar@battlestar-galactica.com> wrote:
    On Sun, 26 Oct 2025 21:25:07 GMT
    Recliner <recliner.usenet@gmail.com> wrote:
    <boltar@battlestar-galactica.com> wrote:
    Odd choice to use phase given there'll be points where the signals from 2 >>> cables will cancel plus its more complicated to detect phase changes. Why >>> on earth didn't they just use 2 seperate frequencies?

    The crossing points are called null points, for precisely that reason.

    How would using two frequencies work?

    Is this is a trick question?

    No rCo please explain.

    --- Synchronet 3.21a-Linux NewsLink 1.2
  • From boltar@boltar@caprica.universe to uk.transport.london,uk.railway on Tue Oct 28 16:02:16 2025
    From Newsgroup: uk.transport.london

    On Mon, 27 Oct 2025 22:35:00 GMT
    Recliner <recliner.usenet@gmail.com> gabbled: ><boltar@battlestar-galactica.com> wrote:
    On Sun, 26 Oct 2025 21:25:07 GMT
    Recliner <recliner.usenet@gmail.com> wrote:
    <boltar@battlestar-galactica.com> wrote:
    Odd choice to use phase given there'll be points where the signals from 2 >>>> cables will cancel plus its more complicated to detect phase changes. Why >>>> on earth didn't they just use 2 seperate frequencies?

    The crossing points are called null points, for precisely that reason.

    How would using two frequencies work?

    Is this is a trick question?

    No rCo please explain.

    Arn't you always telling us what a genius engineer you are?

    Have the 2 frequencies one after the other on the line. A couple of simple band pass filters with level detection and your sorted.

    --- Synchronet 3.21a-Linux NewsLink 1.2
  • From Recliner@recliner.usenet@gmail.com to uk.railway,uk.transport.london on Tue Oct 28 16:23:37 2025
    From Newsgroup: uk.transport.london

    <boltar@caprica.universe> wrote:
    On Mon, 27 Oct 2025 22:35:00 GMT
    Recliner <recliner.usenet@gmail.com> gabbled:
    <boltar@battlestar-galactica.com> wrote:
    On Sun, 26 Oct 2025 21:25:07 GMT
    Recliner <recliner.usenet@gmail.com> wrote:
    <boltar@battlestar-galactica.com> wrote:
    Odd choice to use phase given there'll be points where the signals from 2 >>>>> cables will cancel plus its more complicated to detect phase changes. Why >>>>> on earth didn't they just use 2 seperate frequencies?

    The crossing points are called null points, for precisely that reason. >>>>
    How would using two frequencies work?

    Is this is a trick question?

    No rCo please explain.

    Arn't you always telling us what a genius engineer you are?

    Have the 2 frequencies one after the other on the line. A couple of simple band pass filters with level detection and your sorted.


    ThererCOs just one pair of wires in the four foot, which together form the aerial, and no electronic devices. So how would your system deliver a
    variable frequency system?

    --- Synchronet 3.21a-Linux NewsLink 1.2
  • From boltar@boltar@caprica.universe to uk.railway,uk.transport.london on Tue Oct 28 16:47:24 2025
    From Newsgroup: uk.transport.london

    On Tue, 28 Oct 2025 16:23:37 GMT
    Recliner <recliner.usenet@gmail.com> gabbled:
    <boltar@caprica.universe> wrote:
    On Mon, 27 Oct 2025 22:35:00 GMT
    Recliner <recliner.usenet@gmail.com> gabbled:
    <boltar@battlestar-galactica.com> wrote:
    On Sun, 26 Oct 2025 21:25:07 GMT
    Recliner <recliner.usenet@gmail.com> wrote:
    <boltar@battlestar-galactica.com> wrote:
    Odd choice to use phase given there'll be points where the signals from 2

    cables will cancel plus its more complicated to detect phase changes. Why

    on earth didn't they just use 2 seperate frequencies?

    The crossing points are called null points, for precisely that reason. >>>>>
    How would using two frequencies work?

    Is this is a trick question?

    No rCo please explain.

    Arn't you always telling us what a genius engineer you are?

    Have the 2 frequencies one after the other on the line. A couple of simple >> band pass filters with level detection and your sorted.


    ThererCOs just one pair of wires in the four foot, which together form the >aerial, and no electronic devices. So how would your system deliver a >variable frequency system?

    How does it deliver a phase shifted system?

    --- Synchronet 3.21a-Linux NewsLink 1.2
  • From Recliner@recliner.usenet@gmail.com to uk.railway,uk.transport.london on Tue Oct 28 17:41:26 2025
    From Newsgroup: uk.transport.london

    <boltar@caprica.universe> wrote:
    On Tue, 28 Oct 2025 16:23:37 GMT
    Recliner <recliner.usenet@gmail.com> gabbled:
    <boltar@caprica.universe> wrote:
    On Mon, 27 Oct 2025 22:35:00 GMT
    Recliner <recliner.usenet@gmail.com> gabbled:
    <boltar@battlestar-galactica.com> wrote:
    On Sun, 26 Oct 2025 21:25:07 GMT
    Recliner <recliner.usenet@gmail.com> wrote:
    <boltar@battlestar-galactica.com> wrote:
    Odd choice to use phase given there'll be points where the signals from 2

    cables will cancel plus its more complicated to detect phase changes. Why

    on earth didn't they just use 2 seperate frequencies?

    The crossing points are called null points, for precisely that reason. >>>>>>
    How would using two frequencies work?

    Is this is a trick question?

    No rCo please explain.

    Arn't you always telling us what a genius engineer you are?

    Have the 2 frequencies one after the other on the line. A couple of simple >>> band pass filters with level detection and your sorted.


    ThererCOs just one pair of wires in the four foot, which together form the >> aerial, and no electronic devices. So how would your system deliver a
    variable frequency system?

    How does it deliver a phase shifted system?


    Read the thread.

    --- Synchronet 3.21a-Linux NewsLink 1.2
  • From Clank@clank75@googlemail.com to uk.railway,uk.transport.london on Tue Oct 28 20:49:37 2025
    From Newsgroup: uk.transport.london

    On 28/10/2025 18:47, boltar@caprica.universe wrote:
    On Tue, 28 Oct 2025 16:23:37 GMT
    Recliner <recliner.usenet@gmail.com> gabbled:
    <boltar@caprica.universe> wrote:
    On Mon, 27 Oct 2025 22:35:00 GMT
    Recliner <recliner.usenet@gmail.com> gabbled:
    <boltar@battlestar-galactica.com> wrote:
    On Sun, 26 Oct 2025 21:25:07 GMT
    Recliner <recliner.usenet@gmail.com> wrote:
    <boltar@battlestar-galactica.com> wrote:
    Odd choice to use phase given there'll be points where the signals from 2

    cables will cancel plus its more complicated to detect phase changes. Why

    on earth didn't they just use 2 seperate frequencies?

    The crossing points are called null points, for precisely that reason. >>>>>>
    How would using two frequencies work?

    Is this is a trick question?

    No rCo please explain.

    Arn't you always telling us what a genius engineer you are?

    Have the 2 frequencies one after the other on the line. A couple of simple >>> band pass filters with level detection and your sorted.


    ThererCOs just one pair of wires in the four foot, which together form the >> aerial, and no electronic devices. So how would your system deliver a
    variable frequency system?

    How does it deliver a phase shifted system?

    By crossing the streams (TM Ghostbusters) every few feet, based on what
    I'm reading above. Sounds like they basically implement a simple linear encoder with a long loop* of cable, and each time the two wires cross
    you get another 'tick' on the encoder, detected by the phase change of
    the received signal (the signal will flip 180 degrees when the cables
    swap sides.)

    Quite neat, really! Getting a secondary benefit - detection of linear movement - out of the same loop of cable you had to install anyway to communicate the ATC signals to the train.


    Phase detection is also pretty trivial - easier than your two bandpass filters. You just need a local oscillator generating a reference
    signal, and 4 Schottky diodes, and that's it. (In fact given we don't
    even need to detect the phase, we just need to detect when it changed
    180 degrees, you can probably do it even more simply.)

    In any event, phase detection is not some novel complex technology; it's
    a fundamental part of a phase-locked loop, which is the basis for
    practically every radio receiver design in living memory (and plenty of applications outside of RF as well - e.g. maintaining clock
    synchronisation on data buses.) They probably didn't even need any
    additional components, since they need a receiver for the ATC signal anyway.



    * so strictly speaking it's not a pair of wires, it's one long wire
    looping back on itself.


    --- Synchronet 3.21a-Linux NewsLink 1.2
  • From Recliner@recliner.usenet@gmail.com to uk.railway,uk.transport.london on Tue Oct 28 22:35:09 2025
    From Newsgroup: uk.transport.london

    Clank <clank75@googlemail.com> wrote:
    On 28/10/2025 18:47, boltar@caprica.universe wrote:
    On Tue, 28 Oct 2025 16:23:37 GMT
    Recliner <recliner.usenet@gmail.com> gabbled:
    <boltar@caprica.universe> wrote:
    On Mon, 27 Oct 2025 22:35:00 GMT
    Recliner <recliner.usenet@gmail.com> gabbled:
    <boltar@battlestar-galactica.com> wrote:
    On Sun, 26 Oct 2025 21:25:07 GMT
    Recliner <recliner.usenet@gmail.com> wrote:
    <boltar@battlestar-galactica.com> wrote:
    Odd choice to use phase given there'll be points where the signals from 2

    cables will cancel plus its more complicated to detect phase changes. Why

    on earth didn't they just use 2 seperate frequencies?

    The crossing points are called null points, for precisely that reason. >>>>>>>
    How would using two frequencies work?

    Is this is a trick question?

    No rCo please explain.

    Arn't you always telling us what a genius engineer you are?

    Have the 2 frequencies one after the other on the line. A couple of simple >>>> band pass filters with level detection and your sorted.


    ThererCOs just one pair of wires in the four foot, which together form the >>> aerial, and no electronic devices. So how would your system deliver a
    variable frequency system?

    How does it deliver a phase shifted system?

    By crossing the streams (TM Ghostbusters) every few feet, based on what
    I'm reading above.

    Every 25m. The trainrCOs odometers are used to measure distances within that block.

    Sounds like they basically implement a simple linear
    encoder with a long loop* of cable, and each time the two wires cross
    you get another 'tick' on the encoder, detected by the phase change of
    the received signal (the signal will flip 180 degrees when the cables
    swap sides.)

    Quite neat, really! Getting a secondary benefit - detection of linear movement - out of the same loop of cable you had to install anyway to communicate the ATC signals to the train.


    Phase detection is also pretty trivial - easier than your two bandpass filters. You just need a local oscillator generating a reference
    signal, and 4 Schottky diodes, and that's it. (In fact given we don't
    even need to detect the phase, we just need to detect when it changed
    180 degrees, you can probably do it even more simply.)

    In any event, phase detection is not some novel complex technology; it's
    a fundamental part of a phase-locked loop, which is the basis for practically every radio receiver design in living memory (and plenty of applications outside of RF as well - e.g. maintaining clock
    synchronisation on data buses.) They probably didn't even need any additional components, since they need a receiver for the ATC signal anyway.


    * so strictly speaking it's not a pair of wires, it's one long wire
    looping back on itself.

    Yes, and itrCOs actually referred to as a loop. It can be up to 1 km long.

    --- Synchronet 3.21a-Linux NewsLink 1.2
  • From Sam Wilson@ukr@dummy.wislons.fastmail.co.uk to uk.railway,uk.transport.london on Wed Oct 29 11:48:11 2025
    From Newsgroup: uk.transport.london

    Tweed <usenet.tweed@gmail.com> wrote:
    <boltar@caprica.universe> wrote:
    On Fri, 24 Oct 2025 15:55:15 GMT
    Recliner <recliner.usenet@gmail.com> gabbled:
    <boltar@caprica.universe> wrote:
    Surely any issue with the cables would have been evident in about 5 mins >>>> once they had their test equipment on site.


    Obviously, it wasnrCOt that simple. The cables would still be transmitting >>> their usual signals, but if the cables were slightly displaced, the
    reception on the trains might have been marginal, hence the intermittent >>> nature of the reported fault.

    Which should have been obvious with any decent test equipment. Anyway, I
    suspect the changes of the cables being displaced enough to cause issues is >> highly unlikely. Probably a hardware fault further upstream.


    Have you done any debugging of electronics? Even with the best equipment available a subtle fault can be hard to find, and thatrCOs in the comfort of a lab. Gets much harder in a dirty tube tunnel with limited access time.
    The fault is usually blindingly obvious once yourCOve identified it, but getting to that point can be hard.

    <AOL>

    Sam
    --
    The entity formerly known as Sam.Wilson@ed.ac.uk
    Spit the dummy to reply
    --- Synchronet 3.21a-Linux NewsLink 1.2
  • From boltar@boltar@caprica.universe to uk.railway,uk.transport.london on Wed Oct 29 15:23:37 2025
    From Newsgroup: uk.transport.london

    On Tue, 28 Oct 2025 20:49:37 +0200
    Clank <clank75@googlemail.com> gabbled:
    On 28/10/2025 18:47, boltar@caprica.universe wrote:
    ThererCOs just one pair of wires in the four foot, which together form the >>> aerial, and no electronic devices. So how would your system deliver a
    variable frequency system?

    How does it deliver a phase shifted system?

    By crossing the streams (TM Ghostbusters) every few feet, based on what
    I'm reading above. Sounds like they basically implement a simple linear >encoder with a long loop* of cable, and each time the two wires cross
    you get another 'tick' on the encoder, detected by the phase change of
    the received signal (the signal will flip 180 degrees when the cables
    swap sides.)

    Quite neat, really! Getting a secondary benefit - detection of linear >movement - out of the same loop of cable you had to install anyway to >communicate the ATC signals to the train.


    Phase detection is also pretty trivial - easier than your two bandpass >filters. You just need a local oscillator generating a reference

    Almost irrelevant for something the size of a train. Simple analogue filter chips cost buttons.

    signal, and 4 Schottky diodes, and that's it. (In fact given we don't
    even need to detect the phase, we just need to detect when it changed
    180 degrees, you can probably do it even more simply.)

    I don't imagine detecting the phase change is much good because taking any given point on the cable the relative phase of other points of the cable will vary all the way from 0 to 180 degrees and back again so you can't have one section of cable at 0 phase and another at 180.

    Detecting the null point seems rather asking for problems given depending
    on the frequency used the cable crossover would need to be set up very accurately - the higher the hz, the less it would take to knock it out of alignment.

    * so strictly speaking it's not a pair of wires, it's one long wire
    looping back on itself.

    2 wires with 2 frequencies seems like it would be far more robust but then
    no doubt it would cost more to install so they didn't bother.

    --- Synchronet 3.21a-Linux NewsLink 1.2
  • From Recliner@recliner.usenet@gmail.com to uk.railway,uk.transport.london on Wed Oct 29 16:13:21 2025
    From Newsgroup: uk.transport.london

    <boltar@caprica.universe> wrote:
    On Tue, 28 Oct 2025 20:49:37 +0200
    Clank <clank75@googlemail.com> gabbled:
    On 28/10/2025 18:47, boltar@caprica.universe wrote:
    ThererCOs just one pair of wires in the four foot, which together form the >>>> aerial, and no electronic devices. So how would your system deliver a
    variable frequency system?

    How does it deliver a phase shifted system?

    By crossing the streams (TM Ghostbusters) every few feet, based on what
    I'm reading above. Sounds like they basically implement a simple linear
    encoder with a long loop* of cable, and each time the two wires cross
    you get another 'tick' on the encoder, detected by the phase change of
    the received signal (the signal will flip 180 degrees when the cables
    swap sides.)

    Quite neat, really! Getting a secondary benefit - detection of linear
    movement - out of the same loop of cable you had to install anyway to
    communicate the ATC signals to the train.


    Phase detection is also pretty trivial - easier than your two bandpass
    filters. You just need a local oscillator generating a reference

    Almost irrelevant for something the size of a train. Simple analogue filter chips cost buttons.

    signal, and 4 Schottky diodes, and that's it. (In fact given we don't
    even need to detect the phase, we just need to detect when it changed
    180 degrees, you can probably do it even more simply.)

    I don't imagine detecting the phase change is much good because taking any given point on the cable the relative phase of other points of the cable will
    vary all the way from 0 to 180 degrees and back again so you can't have one section of cable at 0 phase and another at 180.

    Rubbish. The phase change happens quickly, and then stays constant till the next null point.


    Detecting the null point seems rather asking for problems given depending
    on the frequency used the cable crossover would need to be set up very accurately - the higher the hz, the less it would take to knock it out of alignment.

    * so strictly speaking it's not a pair of wires, it's one long wire
    looping back on itself.

    2 wires with 2 frequencies seems like it would be far more robust but then
    no doubt it would cost more to install so they didn't bother.

    How would that allow trains to detect their position?

    --- Synchronet 3.21a-Linux NewsLink 1.2
  • From Certes@Certes@example.org to uk.railway,uk.transport.london on Wed Oct 29 18:12:28 2025
    From Newsgroup: uk.transport.london

    On 29/10/2025 16:13, Recliner wrote:
    <boltar@caprica.universe> wrote:
    On Tue, 28 Oct 2025 20:49:37 +0200
    Clank <clank75@googlemail.com> gabbled:
    On 28/10/2025 18:47, boltar@caprica.universe wrote:
    ThererCOs just one pair of wires in the four foot, which together form the
    aerial, and no electronic devices. So how would your system deliver a >>>>> variable frequency system?

    How does it deliver a phase shifted system?

    By crossing the streams (TM Ghostbusters) every few feet, based on what
    I'm reading above. Sounds like they basically implement a simple linear >>> encoder with a long loop* of cable, and each time the two wires cross
    you get another 'tick' on the encoder, detected by the phase change of
    the received signal (the signal will flip 180 degrees when the cables
    swap sides.)

    Quite neat, really! Getting a secondary benefit - detection of linear
    movement - out of the same loop of cable you had to install anyway to
    communicate the ATC signals to the train.


    Phase detection is also pretty trivial - easier than your two bandpass
    filters. You just need a local oscillator generating a reference

    Almost irrelevant for something the size of a train. Simple analogue filter >> chips cost buttons.

    signal, and 4 Schottky diodes, and that's it. (In fact given we don't
    even need to detect the phase, we just need to detect when it changed
    180 degrees, you can probably do it even more simply.)

    I don't imagine detecting the phase change is much good because taking any >> given point on the cable the relative phase of other points of the cable will
    vary all the way from 0 to 180 degrees and back again so you can't have one >> section of cable at 0 phase and another at 180.

    Rubbish. The phase change happens quickly, and then stays constant till the next null point.

    Indeed.

    Detecting the null point seems rather asking for problems given depending
    on the frequency used the cable crossover would need to be set up very
    accurately - the higher the hz, the less it would take to knock it out of
    alignment.

    * so strictly speaking it's not a pair of wires, it's one long wire
    looping back on itself.

    2 wires with 2 frequencies seems like it would be far more robust but then >> no doubt it would cost more to install so they didn't bother.

    How would that allow trains to detect their position?

    They'd count frequency changes rather than phase changes. It works, but
    is more complex in hardware and software than the current arrangement.
    --- Synchronet 3.21a-Linux NewsLink 1.2
  • From Recliner@recliner.usenet@gmail.com to uk.railway,uk.transport.london on Wed Oct 29 21:07:50 2025
    From Newsgroup: uk.transport.london

    Certes <Certes@example.org> wrote:
    On 29/10/2025 16:13, Recliner wrote:
    <boltar@caprica.universe> wrote:
    On Tue, 28 Oct 2025 20:49:37 +0200
    Clank <clank75@googlemail.com> gabbled:
    On 28/10/2025 18:47, boltar@caprica.universe wrote:
    ThererCOs just one pair of wires in the four foot, which together form the
    aerial, and no electronic devices. So how would your system deliver a >>>>>> variable frequency system?

    How does it deliver a phase shifted system?

    By crossing the streams (TM Ghostbusters) every few feet, based on what >>>> I'm reading above. Sounds like they basically implement a simple linear >>>> encoder with a long loop* of cable, and each time the two wires cross
    you get another 'tick' on the encoder, detected by the phase change of >>>> the received signal (the signal will flip 180 degrees when the cables
    swap sides.)

    Quite neat, really! Getting a secondary benefit - detection of linear >>>> movement - out of the same loop of cable you had to install anyway to
    communicate the ATC signals to the train.


    Phase detection is also pretty trivial - easier than your two bandpass >>>> filters. You just need a local oscillator generating a reference

    Almost irrelevant for something the size of a train. Simple analogue filter >>> chips cost buttons.

    signal, and 4 Schottky diodes, and that's it. (In fact given we don't >>>> even need to detect the phase, we just need to detect when it changed
    180 degrees, you can probably do it even more simply.)

    I don't imagine detecting the phase change is much good because taking any >>> given point on the cable the relative phase of other points of the cable will
    vary all the way from 0 to 180 degrees and back again so you can't have one >>> section of cable at 0 phase and another at 180.

    Rubbish. The phase change happens quickly, and then stays constant till the >> next null point.

    Indeed.

    Detecting the null point seems rather asking for problems given depending >>> on the frequency used the cable crossover would need to be set up very
    accurately - the higher the hz, the less it would take to knock it out of >>> alignment.

    * so strictly speaking it's not a pair of wires, it's one long wire
    looping back on itself.

    2 wires with 2 frequencies seems like it would be far more robust but then >>> no doubt it would cost more to install so they didn't bother.

    How would that allow trains to detect their position?

    They'd count frequency changes rather than phase changes. It works, but
    is more complex in hardware and software than the current arrangement.


    How would the radiated frequency change every 25m?

    --- Synchronet 3.21a-Linux NewsLink 1.2
  • From Certes@Certes@example.org to uk.railway,uk.transport.london on Wed Oct 29 21:48:15 2025
    From Newsgroup: uk.transport.london

    On 29/10/2025 21:07, Recliner wrote:
    Certes <Certes@example.org> wrote:
    On 29/10/2025 16:13, Recliner wrote:
    <boltar@caprica.universe> wrote:
    On Tue, 28 Oct 2025 20:49:37 +0200
    Clank <clank75@googlemail.com> gabbled:
    On 28/10/2025 18:47, boltar@caprica.universe wrote:
    ThererCOs just one pair of wires in the four foot, which together form the
    aerial, and no electronic devices. So how would your system deliver a >>>>>>> variable frequency system?

    How does it deliver a phase shifted system?

    By crossing the streams (TM Ghostbusters) every few feet, based on what >>>>> I'm reading above. Sounds like they basically implement a simple linear >>>>> encoder with a long loop* of cable, and each time the two wires cross >>>>> you get another 'tick' on the encoder, detected by the phase change of >>>>> the received signal (the signal will flip 180 degrees when the cables >>>>> swap sides.)

    Quite neat, really! Getting a secondary benefit - detection of linear >>>>> movement - out of the same loop of cable you had to install anyway to >>>>> communicate the ATC signals to the train.


    Phase detection is also pretty trivial - easier than your two bandpass >>>>> filters. You just need a local oscillator generating a reference

    Almost irrelevant for something the size of a train. Simple analogue filter
    chips cost buttons.

    signal, and 4 Schottky diodes, and that's it. (In fact given we don't >>>>> even need to detect the phase, we just need to detect when it changed >>>>> 180 degrees, you can probably do it even more simply.)

    I don't imagine detecting the phase change is much good because taking any >>>> given point on the cable the relative phase of other points of the cable will
    vary all the way from 0 to 180 degrees and back again so you can't have one
    section of cable at 0 phase and another at 180.

    Rubbish. The phase change happens quickly, and then stays constant till the >>> next null point.

    Indeed.

    Detecting the null point seems rather asking for problems given depending >>>> on the frequency used the cable crossover would need to be set up very >>>> accurately - the higher the hz, the less it would take to knock it out of >>>> alignment.

    * so strictly speaking it's not a pair of wires, it's one long wire
    looping back on itself.

    2 wires with 2 frequencies seems like it would be far more robust but then >>>> no doubt it would cost more to install so they didn't bother.

    How would that allow trains to detect their position?

    They'd count frequency changes rather than phase changes. It works, but
    is more complex in hardware and software than the current arrangement.

    How would the radiated frequency change every 25m?

    I didn't devise this inferior scheme, but I guess each wire would have shielding which starts and stops every 25m, one pair's shield starting
    where the other stops. I can understand why the actual design was used.
    --- Synchronet 3.21a-Linux NewsLink 1.2
  • From Recliner@recliner.usenet@gmail.com to uk.railway,uk.transport.london on Wed Oct 29 22:04:55 2025
    From Newsgroup: uk.transport.london

    Certes <Certes@example.org> wrote:
    On 29/10/2025 21:07, Recliner wrote:
    Certes <Certes@example.org> wrote:
    On 29/10/2025 16:13, Recliner wrote:
    <boltar@caprica.universe> wrote:
    On Tue, 28 Oct 2025 20:49:37 +0200
    Clank <clank75@googlemail.com> gabbled:
    On 28/10/2025 18:47, boltar@caprica.universe wrote:
    ThererCOs just one pair of wires in the four foot, which together form the
    aerial, and no electronic devices. So how would your system deliver a >>>>>>>> variable frequency system?

    How does it deliver a phase shifted system?

    By crossing the streams (TM Ghostbusters) every few feet, based on what >>>>>> I'm reading above. Sounds like they basically implement a simple linear >>>>>> encoder with a long loop* of cable, and each time the two wires cross >>>>>> you get another 'tick' on the encoder, detected by the phase change of >>>>>> the received signal (the signal will flip 180 degrees when the cables >>>>>> swap sides.)

    Quite neat, really! Getting a secondary benefit - detection of linear >>>>>> movement - out of the same loop of cable you had to install anyway to >>>>>> communicate the ATC signals to the train.


    Phase detection is also pretty trivial - easier than your two bandpass >>>>>> filters. You just need a local oscillator generating a reference

    Almost irrelevant for something the size of a train. Simple analogue filter
    chips cost buttons.

    signal, and 4 Schottky diodes, and that's it. (In fact given we don't >>>>>> even need to detect the phase, we just need to detect when it changed >>>>>> 180 degrees, you can probably do it even more simply.)

    I don't imagine detecting the phase change is much good because taking any
    given point on the cable the relative phase of other points of the cable will
    vary all the way from 0 to 180 degrees and back again so you can't have one
    section of cable at 0 phase and another at 180.

    Rubbish. The phase change happens quickly, and then stays constant till the
    next null point.

    Indeed.

    Detecting the null point seems rather asking for problems given depending >>>>> on the frequency used the cable crossover would need to be set up very >>>>> accurately - the higher the hz, the less it would take to knock it out of >>>>> alignment.

    * so strictly speaking it's not a pair of wires, it's one long wire >>>>>> looping back on itself.

    2 wires with 2 frequencies seems like it would be far more robust but then
    no doubt it would cost more to install so they didn't bother.

    How would that allow trains to detect their position?

    They'd count frequency changes rather than phase changes. It works, but >>> is more complex in hardware and software than the current arrangement.

    How would the radiated frequency change every 25m?

    I didn't devise this inferior scheme, but I guess each wire would have shielding which starts and stops every 25m, one pair's shield starting
    where the other stops. I can understand why the actual design was used.


    Yes, inferior it certainly is: more than twice as expensive, much more
    complex to install, more than twice as many failure points, but with no advantages at all.

    --- Synchronet 3.21a-Linux NewsLink 1.2
  • From Clank@clank75@googlemail.com to uk.railway,uk.transport.london on Thu Oct 30 10:43:52 2025
    From Newsgroup: uk.transport.london

    On 29/10/2025 17:23, boltar@caprica.universe wrote:
    On Tue, 28 Oct 2025 20:49:37 +0200
    Clank <clank75@googlemail.com> gabbled:
    On 28/10/2025 18:47, boltar@caprica.universe wrote:
    ThererCOs just one pair of wires in the four foot, which together form >>>> the
    aerial, and no electronic devices. So how would your system deliver a
    variable frequency system?

    How does it deliver a phase shifted system?

    By crossing the streams (TM Ghostbusters) every few feet, based on
    what I'm reading above.-a Sounds like they basically implement a simple
    linear encoder with a long loop* of cable, and each time the two wires
    cross you get another 'tick' on the encoder, detected by the phase
    change of the received signal (the signal will flip 180 degrees when
    the cables swap sides.)

    Quite neat, really!-a Getting a secondary benefit - detection of linear
    movement - out of the same loop of cable you had to install anyway to
    communicate the ATC signals to the train.


    Phase detection is also pretty trivial - easier than your two bandpass
    filters.-a You just need a local oscillator generating a reference

    Almost irrelevant for something the size of a train. Simple analogue
    filter chips cost buttons.

    signal, and 4 Schottky diodes, and that's it.-a (In fact given we don't
    even need to detect the phase, we just need to detect when it changed
    180 degrees, you can probably do it even more simply.)

    I don't imagine detecting the phase change is much good because taking
    any given point on the cable the relative phase of other points of the
    cable will vary all the way from 0 to 180 degrees and back again so you can't have one section of cable at 0 phase and another at 180.

    Detecting the null point seems rather asking for problems given depending
    on the frequency used the cable crossover would need to be set up very accurately - the higher the hz, the less it would take to knock it out of alignment.

    * so strictly speaking it's not a pair of wires, it's one long wire
    looping back on itself.

    2 wires with 2 frequencies seems like it would be far more robust but then
    no doubt it would cost more to install so they didn't bother.

    Have you ever considered *not* pontificating on things which you are
    clearly completely unqualified for? For the avoidance of doubt, having
    a Radio Shack 150-in-1 Electronic Project Kit in the 1970s is not a
    recognised qualification.

    Honestly, it's super liberating winding your neck in when you're
    clueless about something - that's why you don't see me commenting on
    threads about cars. You can save so much time.



    (Incidentally, the loop with crossings & phase-change detection used in Seltrac was first developed in the *1950s*, and deployed in the 1960s.
    I'm surprised that Ulf hasn't already popped up to note that it's also
    known as "LZB" and reliably provides in-cab signalling to many hundreds
    of kilometres of high-speed rail lines in Germany, Austria and Spain.)


    --- Synchronet 3.21a-Linux NewsLink 1.2
  • From boltar@boltar@caprica.universe to uk.railway,uk.transport.london on Thu Oct 30 10:03:00 2025
    From Newsgroup: uk.transport.london

    On Wed, 29 Oct 2025 16:13:21 GMT
    Recliner <recliner.usenet@gmail.com> gabbled:
    <boltar@caprica.universe> wrote:
    I don't imagine detecting the phase change is much good because taking any >> given point on the cable the relative phase of other points of the cable >will
    vary all the way from 0 to 180 degrees and back again so you can't have one >> section of cable at 0 phase and another at 180.

    Rubbish. The phase change happens quickly, and then stays constant till the >next null point.

    Really? You do realise the phase relative to whats measuring it would constantly change along the length of the wire. Its why 10base2 ethernet could only have specific lengths before the terminator at the end otherwise you'd get destructive interference at certain points due to reflection.

    2 wires with 2 frequencies seems like it would be far more robust but then >> no doubt it would cost more to install so they didn't bother.

    How would that allow trains to detect their position?

    How do you think.

    --- Synchronet 3.21a-Linux NewsLink 1.2
  • From boltar@boltar@caprica.universe to uk.railway,uk.transport.london on Thu Oct 30 10:04:30 2025
    From Newsgroup: uk.transport.london

    On Wed, 29 Oct 2025 18:12:28 +0000
    Certes <Certes@example.org> gabbled:
    On 29/10/2025 16:13, Recliner wrote:
    How would that allow trains to detect their position?

    They'd count frequency changes rather than phase changes. It works, but
    is more complex in hardware and software than the current arrangement.

    Why would it be more complex? Please explain.

    --- Synchronet 3.21a-Linux NewsLink 1.2
  • From boltar@boltar@caprica.universe to uk.railway,uk.transport.london on Thu Oct 30 10:05:04 2025
    From Newsgroup: uk.transport.london

    On Wed, 29 Oct 2025 21:07:50 GMT
    Recliner <recliner.usenet@gmail.com> gabbled:
    Certes <Certes@example.org> wrote:
    They'd count frequency changes rather than phase changes. It works, but
    is more complex in hardware and software than the current arrangement.


    How would the radiated frequency change every 25m?

    You really are having a lot of senior moments this week. Go have a lie down.

    --- Synchronet 3.21a-Linux NewsLink 1.2
  • From boltar@boltar@caprica.universe to uk.railway,uk.transport.london on Thu Oct 30 10:06:45 2025
    From Newsgroup: uk.transport.london

    On Thu, 30 Oct 2025 10:43:52 +0200
    Clank <clank75@googlemail.com> gabbled:
    On 29/10/2025 17:23, boltar@caprica.universe wrote:
    2 wires with 2 frequencies seems like it would be far more robust but then >> no doubt it would cost more to install so they didn't bother.

    Have you ever considered *not* pontificating on things which you are
    clearly completely unqualified for? For the avoidance of doubt, having

    It never stopped you in the past.

    a Radio Shack 150-in-1 Electronic Project Kit in the 1970s is not a >recognised qualification.

    Honestly, it's super liberating winding your neck in when you're
    clueless about something - that's why you don't see me commenting on
    threads about cars. You can save so much time.

    Blah blah , get to your point...

    (Incidentally, the loop with crossings & phase-change detection used in >Seltrac was first developed in the *1950s*, and deployed in the 1960s.
    I'm surprised that Ulf hasn't already popped up to note that it's also
    known as "LZB" and reliably provides in-cab signalling to many hundreds
    of kilometres of high-speed rail lines in Germany, Austria and Spain.)

    Oh right, you didn't have one. As usual.

    --- Synchronet 3.21a-Linux NewsLink 1.2
  • From boltar@boltar@caprica.universe to uk.railway,uk.transport.london on Thu Oct 30 10:16:42 2025
    From Newsgroup: uk.transport.london

    On Wed, 29 Oct 2025 21:48:15 +0000
    Certes <Certes@example.org> gabbled:
    On 29/10/2025 21:07, Recliner wrote:
    How would the radiated frequency change every 25m?

    I didn't devise this inferior scheme, but I guess each wire would have >shielding which starts and stops every 25m, one pair's shield starting
    where the other stops. I can understand why the actual design was used.

    No shielding required. You'd measure the relative levels of the signals,
    you wouldn't need to isolate them.

    --- Synchronet 3.21a-Linux NewsLink 1.2
  • From Clank@clank75@googlemail.com to uk.railway,uk.transport.london on Thu Oct 30 12:21:13 2025
    From Newsgroup: uk.transport.london

    On 30/10/2025 12:06, boltar@caprica.universe wrote:
    On Thu, 30 Oct 2025 10:43:52 +0200
    Clank <clank75@googlemail.com> gabbled:
    On 29/10/2025 17:23, boltar@caprica.universe wrote:
    2 wires with 2 frequencies seems like it would be far more robust but
    then
    no doubt it would cost more to install so they didn't bother.

    Have you ever considered *not* pontificating on things which you are
    clearly completely unqualified for?-a For the avoidance of doubt, having

    It never stopped you in the past.

    a Radio Shack 150-in-1 Electronic Project Kit in the 1970s is not a
    recognised qualification.

    Honestly, it's super liberating winding your neck in when you're
    clueless about something - that's why you don't see me commenting on
    threads about cars.-a You can save so much time.

    Blah blah , get to your point...

    (Incidentally, the loop with crossings & phase-change detection used
    in Seltrac was first developed in the *1950s*, and deployed in the
    1960s. I'm surprised that Ulf hasn't already popped up to note that
    it's also known as "LZB" and reliably provides in-cab signalling to
    many hundreds of kilometres of high-speed rail lines in Germany,
    Austria and Spain.)

    Oh right, you didn't have one. As usual.

    My point was, you're making yourself look like an idiot. But as this is
    an endeavour in which you have clearly have considerably more experience
    than I - do carry on. I'll leave you to it.
    --- Synchronet 3.21a-Linux NewsLink 1.2
  • From Recliner@recliner.usenet@gmail.com to uk.railway,uk.transport.london on Thu Oct 30 10:56:09 2025
    From Newsgroup: uk.transport.london

    <boltar@caprica.universe> wrote:
    On Wed, 29 Oct 2025 21:48:15 +0000
    Certes <Certes@example.org> gabbled:
    On 29/10/2025 21:07, Recliner wrote:
    How would the radiated frequency change every 25m?

    I didn't devise this inferior scheme, but I guess each wire would have
    shielding which starts and stops every 25m, one pair's shield starting
    where the other stops. I can understand why the actual design was used.

    No shielding required. You'd measure the relative levels of the signals,
    you wouldn't need to isolate them.


    You still havenrCOt explained how distances will be measured along the tunnel using your ridiculous idea.

    --- Synchronet 3.21a-Linux NewsLink 1.2
  • From Recliner@recliner.usenet@gmail.com to uk.railway,uk.transport.london on Thu Oct 30 10:56:10 2025
    From Newsgroup: uk.transport.london

    <boltar@caprica.universe> wrote:
    On Wed, 29 Oct 2025 18:12:28 +0000
    Certes <Certes@example.org> gabbled:
    On 29/10/2025 16:13, Recliner wrote:
    How would that allow trains to detect their position?

    They'd count frequency changes rather than phase changes. It works, but
    is more complex in hardware and software than the current arrangement.

    Why would it be more complex? Please explain.


    Twice as much of everything, plus additional components not needed in the working system.

    --- Synchronet 3.21a-Linux NewsLink 1.2
  • From Recliner@recliner.usenet@gmail.com to uk.railway,uk.transport.london on Thu Oct 30 10:56:12 2025
    From Newsgroup: uk.transport.london

    <boltar@caprica.universe> wrote:
    On Wed, 29 Oct 2025 16:13:21 GMT
    Recliner <recliner.usenet@gmail.com> gabbled:
    <boltar@caprica.universe> wrote:
    I don't imagine detecting the phase change is much good because taking any >>> given point on the cable the relative phase of other points of the cable
    will
    vary all the way from 0 to 180 degrees and back again so you can't have one
    section of cable at 0 phase and another at 180.

    Rubbish. The phase change happens quickly, and then stays constant till the >> next null point.

    Really? You do realise the phase relative to whats measuring it would constantly change along the length of the wire.

    But it doesnrCOt. It reverses abruptly at the null points, every 25m. Unlike your notional system, this is a widely-used, proven approach that actually works.


    Its why 10base2 ethernet could
    only have specific lengths before the terminator at the end otherwise you'd get
    destructive interference at certain points due to reflection.

    No signals need to be sent along the loop for the phase changes to occur.


    2 wires with 2 frequencies seems like it would be far more robust but then >>> no doubt it would cost more to install so they didn't bother.

    How would that allow trains to detect their position?

    How do you think.

    I have no idea. ItrCOs your grand plan rCo please explain how you think it would work.


    --- Synchronet 3.21a-Linux NewsLink 1.2
  • From Certes@Certes@example.org to uk.railway,uk.transport.london on Thu Oct 30 10:59:36 2025
    From Newsgroup: uk.transport.london

    On 30/10/2025 10:04, boltar@caprica.universe wrote:
    On Wed, 29 Oct 2025 18:12:28 +0000
    Certes <Certes@example.org> gabbled:
    On 29/10/2025 16:13, Recliner wrote:
    How would that allow trains to detect their position?

    They'd count frequency changes rather than phase changes.-a It works, but
    is more complex in hardware and software than the current arrangement.

    Why would it be more complex? Please explain.

    More wires, and more processing to do on the signals from them. But the
    people who chose the installation know far more about this than either
    of us, so let's trust their judgement.

    --- Synchronet 3.21a-Linux NewsLink 1.2
  • From Recliner@recliner.usenet@gmail.com to uk.railway,uk.transport.london on Thu Oct 30 11:49:03 2025
    From Newsgroup: uk.transport.london

    Certes <Certes@example.org> wrote:
    On 30/10/2025 10:04, boltar@caprica.universe wrote:
    On Wed, 29 Oct 2025 18:12:28 +0000
    Certes <Certes@example.org> gabbled:
    On 29/10/2025 16:13, Recliner wrote:
    How would that allow trains to detect their position?

    They'd count frequency changes rather than phase changes.-a It works, but >>> is more complex in hardware and software than the current arrangement.

    Why would it be more complex? Please explain.

    More wires, and more processing to do on the signals from them. But the people who chose the installation know far more about this than either
    of us, so let's trust their judgement.


    Indeed so.

    Incidentally, not surprisingly, the track workers donrCOt like the pair of wires in the four foot, and two pairs would be even worse. So, with the 4LM scheme, LU has switched to the newer Thales radio-based Seltrac system to accurately locate the trains. This whole system is more complicated,
    because the trains are of varying length, and share tracks with other
    trains in some parts, including engineering trains. Also, there are steeply graded leafy sections on the northern part of the Met, where odometer-based distance measurements are less accurate.

    https://www.railengineer.co.uk/progress-with-the-four-lines-modernisation-project/

    --- Synchronet 3.21a-Linux NewsLink 1.2
  • From Tweed@usenet.tweed@gmail.com to uk.railway,uk.transport.london on Thu Oct 30 12:32:02 2025
    From Newsgroup: uk.transport.london

    Recliner <recliner.usenet@gmail.com> wrote:
    Certes <Certes@example.org> wrote:
    On 30/10/2025 10:04, boltar@caprica.universe wrote:
    On Wed, 29 Oct 2025 18:12:28 +0000
    Certes <Certes@example.org> gabbled:
    On 29/10/2025 16:13, Recliner wrote:
    How would that allow trains to detect their position?

    They'd count frequency changes rather than phase changes.-a It works, but >>>> is more complex in hardware and software than the current arrangement.

    Why would it be more complex? Please explain.

    More wires, and more processing to do on the signals from them. But the
    people who chose the installation know far more about this than either
    of us, so let's trust their judgement.


    Indeed so.

    Incidentally, not surprisingly, the track workers donrCOt like the pair of wires in the four foot, and two pairs would be even worse. So, with the 4LM scheme, LU has switched to the newer Thales radio-based Seltrac system to accurately locate the trains. This whole system is more complicated,
    because the trains are of varying length, and share tracks with other
    trains in some parts, including engineering trains. Also, there are steeply graded leafy sections on the northern part of the Met, where odometer-based distance measurements are less accurate.

    https://www.railengineer.co.uk/progress-with-the-four-lines-modernisation-project/



    Thanks for the link. The article doesnrCOt really go into too much technical detail. IrCOm curious to know how the radio link to the train provides
    accurate position information. Any ideas?

    --- Synchronet 3.21a-Linux NewsLink 1.2
  • From Andy Burns@usenet@andyburns.uk to uk.railway,uk.transport.london on Thu Oct 30 13:19:14 2025
    From Newsgroup: uk.transport.london

    Tweed wrote:

    IrCOm curious to know how the radio link to the train provides
    accurate position information. Any ideas?

    I know nothing, other than how to feed search engines ...

    <https://files.core.ac.uk/download/pdf/154333578.pdf>

    --- Synchronet 3.21a-Linux NewsLink 1.2
  • From Tweed@usenet.tweed@gmail.com to uk.railway,uk.transport.london on Thu Oct 30 13:48:20 2025
    From Newsgroup: uk.transport.london

    Andy Burns <usenet@andyburns.uk> wrote:
    Tweed wrote:

    IrCOm curious to know how the radio link to the train provides
    accurate position information. Any ideas?

    I know nothing, other than how to feed search engines ...

    <https://files.core.ac.uk/download/pdf/154333578.pdf>



    ThatrCOs a useful find - thank you. From reading that I conclude that radio
    is not used to determine position, but only to communicate a calculated position. The primary position reference is to pass over a balise placed in
    the 4 foot and then to use a secondary method, eg wheel rotation counting
    or radar, to calculate the offset from that reference.

    --- Synchronet 3.21a-Linux NewsLink 1.2
  • From Sam Wilson@ukr@dummy.wislons.fastmail.co.uk to uk.railway,uk.transport.london on Thu Oct 30 15:24:50 2025
    From Newsgroup: uk.transport.london

    Recliner <recliner.usenet@gmail.com> wrote:
    <boltar@caprica.universe> wrote:
    On Wed, 29 Oct 2025 21:48:15 +0000
    Certes <Certes@example.org> gabbled:
    On 29/10/2025 21:07, Recliner wrote:
    How would the radiated frequency change every 25m?

    I didn't devise this inferior scheme, but I guess each wire would have
    shielding which starts and stops every 25m, one pair's shield starting
    where the other stops. I can understand why the actual design was used.

    No shielding required. You'd measure the relative levels of the signals,
    you wouldn't need to isolate them.


    You still havenrCOt explained how distances will be measured along the tunnel using your ridiculous idea.

    DonrCOt be silly! BoltarrCOs off the cuff ideas are always hugely superior to anything any group of experienced engineers in a specialised field could
    ever devise. Just accept that thererCOs only one boltar and herCOs much too busy to get round to making everying that anyone has ever made better.

    Sam
    --
    The entity formerly known as Sam.Wilson@ed.ac.uk
    Spit the dummy to reply
    --- Synchronet 3.21a-Linux NewsLink 1.2
  • From Recliner@recliner.usenet@gmail.com to uk.railway,uk.transport.london on Thu Oct 30 16:21:23 2025
    From Newsgroup: uk.transport.london

    Tweed <usenet.tweed@gmail.com> wrote:
    Andy Burns <usenet@andyburns.uk> wrote:
    Tweed wrote:

    IrCOm curious to know how the radio link to the train provides
    accurate position information. Any ideas?

    I know nothing, other than how to feed search engines ...

    <https://files.core.ac.uk/download/pdf/154333578.pdf>



    ThatrCOs a useful find - thank you. From reading that I conclude that radio is not used to determine position, but only to communicate a calculated position. The primary position reference is to pass over a balise placed in the 4 foot and then to use a secondary method, eg wheel rotation counting
    or radar, to calculate the offset from that reference.


    Yes, I think there are balises (transponders) in the four foot that provide precise positional information, as with ETCS. I think each transponder
    knows its exact position, so the train doesnrCOt have to count them. IrCOll try to take a look for them next time IrCOm using an SSL train.

    I think the radio link provides the two-way communication link with base:
    the train broadcasts its location, speed and length, and in return gets
    sent frequent instructions on the allowable speed and movement authority.
    This method is presumably more expensive than the simple inductive loops in
    the track, so some of the fixed locations are further than the usual 25m
    apart.

    --- Synchronet 3.21a-Linux NewsLink 1.2
  • From Tweed@usenet.tweed@gmail.com to uk.railway,uk.transport.london on Thu Oct 30 17:02:11 2025
    From Newsgroup: uk.transport.london

    Recliner <recliner.usenet@gmail.com> wrote:
    Tweed <usenet.tweed@gmail.com> wrote:
    Andy Burns <usenet@andyburns.uk> wrote:
    Tweed wrote:

    IrCOm curious to know how the radio link to the train provides
    accurate position information. Any ideas?

    I know nothing, other than how to feed search engines ...

    <https://files.core.ac.uk/download/pdf/154333578.pdf>



    ThatrCOs a useful find - thank you. From reading that I conclude that radio >> is not used to determine position, but only to communicate a calculated
    position. The primary position reference is to pass over a balise placed in >> the 4 foot and then to use a secondary method, eg wheel rotation counting
    or radar, to calculate the offset from that reference.


    Yes, I think there are balises (transponders) in the four foot that provide precise positional information, as with ETCS. I think each transponder
    knows its exact position, so the train doesnrCOt have to count them. IrCOll try
    to take a look for them next time IrCOm using an SSL train.

    I think the radio link provides the two-way communication link with base:
    the train broadcasts its location, speed and length, and in return gets
    sent frequent instructions on the allowable speed and movement authority. This method is presumably more expensive than the simple inductive loops in the track, so some of the fixed locations are further than the usual 25m apart.

    IrCOve noticed that balises have appeared on the Glasgow Subway, presumably
    in preparation for that going fully automatic and eventually driverless.

    --- Synchronet 3.21a-Linux NewsLink 1.2
  • From boltar@boltar@caprica.universe to uk.railway,uk.transport.london on Fri Oct 31 10:26:12 2025
    From Newsgroup: uk.transport.london

    On Thu, 30 Oct 2025 12:21:13 +0200
    Clank <clank75@googlemail.com> gabbled:
    On 30/10/2025 12:06, boltar@caprica.universe wrote:
    On Thu, 30 Oct 2025 10:43:52 +0200
    Clank <clank75@googlemail.com> gabbled:
    On 29/10/2025 17:23, boltar@caprica.universe wrote:
    2 wires with 2 frequencies seems like it would be far more robust but >>>> then
    no doubt it would cost more to install so they didn't bother.

    Have you ever considered *not* pontificating on things which you are
    clearly completely unqualified for?-a For the avoidance of doubt, having >>
    It never stopped you in the past.

    a Radio Shack 150-in-1 Electronic Project Kit in the 1970s is not a
    recognised qualification.

    Honestly, it's super liberating winding your neck in when you're
    clueless about something - that's why you don't see me commenting on
    threads about cars.-a You can save so much time.

    Blah blah , get to your point...

    (Incidentally, the loop with crossings & phase-change detection used
    in Seltrac was first developed in the *1950s*, and deployed in the
    1960s. I'm surprised that Ulf hasn't already popped up to note that
    it's also known as "LZB" and reliably provides in-cab signalling to
    many hundreds of kilometres of high-speed rail lines in Germany,
    Austria and Spain.)

    Oh right, you didn't have one. As usual.

    My point was, you're making yourself look like an idiot. But as this is

    That never stopped you in the past either.

    --- Synchronet 3.21a-Linux NewsLink 1.2
  • From boltar@boltar@caprica.universe to uk.railway,uk.transport.london on Fri Oct 31 10:28:19 2025
    From Newsgroup: uk.transport.london

    On Thu, 30 Oct 2025 10:56:09 GMT
    Recliner <recliner.usenet@gmail.com> gabbled:
    <boltar@caprica.universe> wrote:
    On Wed, 29 Oct 2025 21:48:15 +0000
    Certes <Certes@example.org> gabbled:
    On 29/10/2025 21:07, Recliner wrote:
    How would the radiated frequency change every 25m?

    I didn't devise this inferior scheme, but I guess each wire would have
    shielding which starts and stops every 25m, one pair's shield starting
    where the other stops. I can understand why the actual design was used.

    No shielding required. You'd measure the relative levels of the signals,
    you wouldn't need to isolate them.


    You still havenrCOt explained how distances will be measured along the tunnel >using your ridiculous idea.

    Ok, just for your geriatric brain:

    | | -- = wire
    |---F1---| | = track
    | | F = frequency
    |---F2---|
    | |
    |---F1---|
    | |

    Is that simply enough or do you need it done in crayon with help from Big Ted?

    --- Synchronet 3.21a-Linux NewsLink 1.2
  • From boltar@boltar@caprica.universe to uk.railway,uk.transport.london on Fri Oct 31 10:29:29 2025
    From Newsgroup: uk.transport.london

    On Thu, 30 Oct 2025 10:56:12 GMT
    Recliner <recliner.usenet@gmail.com> gabbled:
    <boltar@caprica.universe> wrote:
    On Wed, 29 Oct 2025 16:13:21 GMT
    Recliner <recliner.usenet@gmail.com> gabbled:
    <boltar@caprica.universe> wrote:
    I don't imagine detecting the phase change is much good because taking any

    given point on the cable the relative phase of other points of the cable >>> will
    vary all the way from 0 to 180 degrees and back again so you can't have >one
    section of cable at 0 phase and another at 180.

    Rubbish. The phase change happens quickly, and then stays constant till the >>> next null point.

    Really? You do realise the phase relative to whats measuring it would
    constantly change along the length of the wire.

    But it doesnrCOt. It reverses abruptly at the null points, every 25m. Unlike

    Umm, yet it does.

    your notional system, this is a widely-used, proven approach that actually >works.


    Its why 10base2 ethernet could
    only have specific lengths before the terminator at the end otherwise you'd >get
    destructive interference at certain points due to reflection.

    No signals need to be sent along the loop for the phase changes to occur.

    So a wire with no signals along it magically has a phase change occur at
    some point with nothing to cause that change.

    Right you are.

    --- Synchronet 3.21a-Linux NewsLink 1.2
  • From boltar@boltar@caprica.universe to uk.railway,uk.transport.london on Fri Oct 31 10:30:48 2025
    From Newsgroup: uk.transport.london

    On Thu, 30 Oct 2025 10:59:36 +0000
    Certes <Certes@example.org> gabbled:
    On 30/10/2025 10:04, boltar@caprica.universe wrote:
    On Wed, 29 Oct 2025 18:12:28 +0000
    Certes <Certes@example.org> gabbled:
    On 29/10/2025 16:13, Recliner wrote:
    How would that allow trains to detect their position?

    They'd count frequency changes rather than phase changes.-a It works, but >>> is more complex in hardware and software than the current arrangement.

    Why would it be more complex? Please explain.

    More wires, and more processing to do on the signals from them. But the >people who chose the installation know far more about this than either
    of us, so let's trust their judgement.

    2 wires instead of 1 and no worrying about crossing points working properly. But then manufacturers always go for the best solution, not the one that just about works but costs far less to make and install hence more profit.

    --- Synchronet 3.21a-Linux NewsLink 1.2
  • From boltar@boltar@caprica.universe to uk.railway,uk.transport.london on Fri Oct 31 10:33:13 2025
    From Newsgroup: uk.transport.london

    On Thu, 30 Oct 2025 11:49:03 GMT
    Recliner <recliner.usenet@gmail.com> gabbled:
    Certes <Certes@example.org> wrote:
    More wires, and more processing to do on the signals from them. But the
    people who chose the installation know far more about this than either
    of us, so let's trust their judgement.


    Indeed so.

    Incidentally, not surprisingly, the track workers donrCOt like the pair of >wires in the four foot, and two pairs would be even worse. So, with the 4LM >scheme, LU has switched to the newer Thales radio-based Seltrac system to >accurately locate the trains. This whole system is more complicated,
    because the trains are of varying length, and share tracks with other

    Why would the length of the train make the slightest bit of difference to
    the computer knowing where it is and how fast its going? The length will be known by the main computer so it'll know when its beyond any crossings etc.

    --- Synchronet 3.21a-Linux NewsLink 1.2
  • From Clank@clank75@googlemail.com to uk.railway,uk.transport.london on Fri Oct 31 12:43:55 2025
    From Newsgroup: uk.transport.london

    On 31/10/2025 12:26, boltar@caprica.universe wrote:
    On Thu, 30 Oct 2025 12:21:13 +0200
    Clank <clank75@googlemail.com> gabbled:
    On 30/10/2025 12:06, boltar@caprica.universe wrote:
    On Thu, 30 Oct 2025 10:43:52 +0200
    Clank <clank75@googlemail.com> gabbled:
    On 29/10/2025 17:23, boltar@caprica.universe wrote:
    2 wires with 2 frequencies seems like it would be far more robust
    but then
    no doubt it would cost more to install so they didn't bother.

    Have you ever considered *not* pontificating on things which you are
    clearly completely unqualified for?-a For the avoidance of doubt, having >>>
    It never stopped you in the past.

    a Radio Shack 150-in-1 Electronic Project Kit in the 1970s is not a
    recognised qualification.

    Honestly, it's super liberating winding your neck in when you're
    clueless about something - that's why you don't see me commenting on
    threads about cars.-a You can save so much time.

    Blah blah , get to your point...

    (Incidentally, the loop with crossings & phase-change detection used
    in Seltrac was first developed in the *1950s*, and deployed in the
    1960s. I'm surprised that Ulf hasn't already popped up to note that
    it's also known as "LZB" and reliably provides in-cab signalling to
    many hundreds of kilometres of high-speed rail lines in Germany,
    Austria and Spain.)

    Oh right, you didn't have one. As usual.

    My point was, you're making yourself look like an idiot.-a But as this is

    That never stopped you in the past either.

    Oh do come along now, you can do better than that I'm sure. Something
    about gypsies or something, you know, your greatest hits. "Nyahhhh, you
    too" - and that's the second time you've been reduced to that this
    thread - really is beneath a troll of your calibre.
    --- Synchronet 3.21a-Linux NewsLink 1.2
  • From Sam Wilson@ukr@dummy.wislons.fastmail.co.uk to uk.railway,uk.transport.london on Fri Oct 31 11:21:21 2025
    From Newsgroup: uk.transport.london

    <boltar@caprica.universe> wrote:
    On Thu, 30 Oct 2025 10:59:36 +0000
    Certes <Certes@example.org> gabbled:
    On 30/10/2025 10:04, boltar@caprica.universe wrote:
    On Wed, 29 Oct 2025 18:12:28 +0000
    Certes <Certes@example.org> gabbled:
    On 29/10/2025 16:13, Recliner wrote:
    How would that allow trains to detect their position?

    They'd count frequency changes rather than phase changes.-a It works, but >>>> is more complex in hardware and software than the current arrangement.

    Why would it be more complex? Please explain.

    More wires, and more processing to do on the signals from them. But the
    people who chose the installation know far more about this than either
    of us, so let's trust their judgement.

    2 wires instead of 1 and no worrying about crossing points working properly. But then manufacturers always go for the best solution, not the one that just about works but costs far less to make and install hence more profit.

    As one of my lecturers pointed out (IrCOm not sure I entirely agree with him) the point of engineering is to make money. If what you design doesnrCOt do that then it may be great art or great something else, but itrCOs not good engineering.

    Sam
    --
    The entity formerly known as Sam.Wilson@ed.ac.uk
    Spit the dummy to reply
    --- Synchronet 3.21a-Linux NewsLink 1.2
  • From Recliner@recliner.usenet@gmail.com to uk.railway,uk.transport.london on Fri Oct 31 11:24:58 2025
    From Newsgroup: uk.transport.london

    <boltar@caprica.universe> wrote:
    On Thu, 30 Oct 2025 10:56:12 GMT
    Recliner <recliner.usenet@gmail.com> gabbled:
    <boltar@caprica.universe> wrote:
    On Wed, 29 Oct 2025 16:13:21 GMT
    Recliner <recliner.usenet@gmail.com> gabbled:
    <boltar@caprica.universe> wrote:
    I don't imagine detecting the phase change is much good because taking any

    given point on the cable the relative phase of other points of the cable >>>> will
    vary all the way from 0 to 180 degrees and back again so you can't have >> one
    section of cable at 0 phase and another at 180.

    Rubbish. The phase change happens quickly, and then stays constant till the
    next null point.

    Really? You do realise the phase relative to whats measuring it would
    constantly change along the length of the wire.

    But it doesnrCOt. It reverses abruptly at the null points, every 25m. Unlike

    Umm, yet it does.

    Yes, exactly. ItrCOs an elegant, simple, reliable system thatrCOs been in service around the world for decades.

    The fault that occurred on the Northern Line was a surprise because itrCOs so rare. Such faults would be frequent with your cockeyed idea.



    your notional system, this is a widely-used, proven approach that actually >> works.


    Its why 10base2 ethernet could
    only have specific lengths before the terminator at the end otherwise you'd >> get
    destructive interference at certain points due to reflection.

    No signals need to be sent along the loop for the phase changes to occur.

    So a wire with no signals along it magically has a phase change occur at
    some point with nothing to cause that change.

    Yup, but there is something obvious and visible to case the phase change,
    which has been mentioned repeatedly in this thread. But your geriatric
    brain simply canrCOt comprehend it. Just look at the DLR for a reminder of
    how it works.


    Right you are.

    Well, obviously.

    And you are, as always, completely wrong. Luckily,we already know that,
    because yourCOre so reliable.


    --- Synchronet 3.21a-Linux NewsLink 1.2
  • From Recliner@recliner.usenet@gmail.com to uk.railway,uk.transport.london on Fri Oct 31 11:42:09 2025
    From Newsgroup: uk.transport.london

    <boltar@caprica.universe> wrote:
    On Thu, 30 Oct 2025 10:56:09 GMT
    Recliner <recliner.usenet@gmail.com> gabbled:
    <boltar@caprica.universe> wrote:
    On Wed, 29 Oct 2025 21:48:15 +0000
    Certes <Certes@example.org> gabbled:
    On 29/10/2025 21:07, Recliner wrote:
    How would the radiated frequency change every 25m?

    I didn't devise this inferior scheme, but I guess each wire would have >>>> shielding which starts and stops every 25m, one pair's shield starting >>>> where the other stops. I can understand why the actual design was used. >>>
    No shielding required. You'd measure the relative levels of the signals, >>> you wouldn't need to isolate them.


    You still havenrCOt explained how distances will be measured along the tunnel
    using your ridiculous idea.

    Ok, just for your geriatric brain:

    | | -- = wire
    |---F1---| | = track
    | | F = frequency
    |---F2---|
    | |
    |---F1---|
    | |

    Is that simply enough or do you need it done in crayon with help from Big Ted?


    Please describe how this would work over a length of several hundred
    metres, providing precise positional information to the train to within a
    few cm, every 25m. Note that you canrCOt have a power supply, junctions or
    any electronic components in the four foot.

    --- Synchronet 3.21a-Linux NewsLink 1.2
  • From Tweed@usenet.tweed@gmail.com to uk.railway,uk.transport.london on Fri Oct 31 13:59:42 2025
    From Newsgroup: uk.transport.london

    Sam Wilson <ukr@dummy.wislons.fastmail.co.uk> wrote:
    <boltar@caprica.universe> wrote:
    On Thu, 30 Oct 2025 10:59:36 +0000
    Certes <Certes@example.org> gabbled:
    On 30/10/2025 10:04, boltar@caprica.universe wrote:
    On Wed, 29 Oct 2025 18:12:28 +0000
    Certes <Certes@example.org> gabbled:
    On 29/10/2025 16:13, Recliner wrote:
    How would that allow trains to detect their position?

    They'd count frequency changes rather than phase changes.-a It works, but >>>>> is more complex in hardware and software than the current arrangement. >>>>
    Why would it be more complex? Please explain.

    More wires, and more processing to do on the signals from them. But the >>> people who chose the installation know far more about this than either
    of us, so let's trust their judgement.

    2 wires instead of 1 and no worrying about crossing points working properly. >> But then manufacturers always go for the best solution, not the one that just
    about works but costs far less to make and install hence more profit.

    As one of my lecturers pointed out (IrCOm not sure I entirely agree with him) the point of engineering is to make money. If what you design doesnrCOt do that then it may be great art or great something else, but itrCOs not good engineering.

    Sam


    Scientific deep space probes employ some rather brilliant engineering, but
    they certainly donrCOt make money. Good engineering might reduce the losses. Even thatrCOs not a certainty, because missions that survive beyond the
    planned lifetime often get extended, with additional costs for ground
    support.

    --- Synchronet 3.21a-Linux NewsLink 1.2
  • From boltar@boltar@caprica.universe to uk.railway,uk.transport.london on Fri Oct 31 15:18:22 2025
    From Newsgroup: uk.transport.london

    On Fri, 31 Oct 2025 12:43:55 +0200
    Clank <clank75@googlemail.com> gabbled:
    On 31/10/2025 12:26, boltar@caprica.universe wrote:
    That never stopped you in the past either.

    Oh do come along now, you can do better than that I'm sure. Something
    about gypsies or something, you know, your greatest hits. "Nyahhhh, you >too" - and that's the second time you've been reduced to that this
    thread - really is beneath a troll of your calibre.

    When you start bathering about how wonderful Romania is again - despite
    a significant percentage of its youngsters leaving - then I might.

    --- Synchronet 3.21a-Linux NewsLink 1.2
  • From boltar@boltar@caprica.universe to uk.railway,uk.transport.london on Fri Oct 31 15:21:59 2025
    From Newsgroup: uk.transport.london

    On Fri, 31 Oct 2025 11:24:58 GMT
    Recliner <recliner.usenet@gmail.com> gabbled:
    <boltar@caprica.universe> wrote:
    Umm, yet it does.

    Yes, exactly. ItrCOs an elegant, simple, reliable system thatrCOs been in >service around the world for decades.

    Whoosh.

    The fault that occurred on the Northern Line was a surprise because itrCOs so >rare. Such faults would be frequent with your cockeyed idea.

    Why's that then?

    So a wire with no signals along it magically has a phase change occur at
    some point with nothing to cause that change.

    Yup, but there is something obvious and visible to case the phase change, >which has been mentioned repeatedly in this thread. But your geriatric
    brain simply canrCOt comprehend it. Just look at the DLR for a reminder of >how it works.

    I'm not sure you have a clue what you're talking about. The phase of a different section of a wire will be different, the overall phase of the signal in the wire won't change however. Also laying out the wire so the phase
    changes enough in a high frequency signal to be noticed requires very
    precise positioning.


    --- Synchronet 3.21a-Linux NewsLink 1.2
  • From boltar@boltar@caprica.universe to uk.railway,uk.transport.london on Fri Oct 31 15:23:08 2025
    From Newsgroup: uk.transport.london

    On Fri, 31 Oct 2025 11:42:09 GMT
    Recliner <recliner.usenet@gmail.com> gabbled:
    <boltar@caprica.universe> wrote:
    You still havenrCOt explained how distances will be measured along the >tunnel
    using your ridiculous idea.

    Ok, just for your geriatric brain:

    | | -- = wire
    |---F1---| | = track
    | | F = frequency
    |---F2---|
    | |
    |---F1---|
    | |

    Is that simply enough or do you need it done in crayon with help from Big >Ted?


    Please describe how this would work over a length of several hundred
    metres, providing precise positional information to the train to within a
    few cm, every 25m. Note that you canrCOt have a power supply, junctions or >any electronic components in the four foot.

    I can't tell if you're genuinely this thick or you're just trolling. I'll be kind and assume the latter.

    --- Synchronet 3.21a-Linux NewsLink 1.2
  • From Sam Wilson@ukr@dummy.wislons.fastmail.co.uk to uk.railway,uk.transport.london on Fri Oct 31 15:29:57 2025
    From Newsgroup: uk.transport.london

    Tweed <usenet.tweed@gmail.com> wrote:
    Sam Wilson <ukr@dummy.wislons.fastmail.co.uk> wrote:
    <boltar@caprica.universe> wrote:
    On Thu, 30 Oct 2025 10:59:36 +0000
    Certes <Certes@example.org> gabbled:
    On 30/10/2025 10:04, boltar@caprica.universe wrote:
    On Wed, 29 Oct 2025 18:12:28 +0000
    Certes <Certes@example.org> gabbled:
    On 29/10/2025 16:13, Recliner wrote:
    How would that allow trains to detect their position?

    They'd count frequency changes rather than phase changes.-a It works, but
    is more complex in hardware and software than the current arrangement. >>>>>
    Why would it be more complex? Please explain.

    More wires, and more processing to do on the signals from them. But the >>>> people who chose the installation know far more about this than either >>>> of us, so let's trust their judgement.

    2 wires instead of 1 and no worrying about crossing points working properly.
    But then manufacturers always go for the best solution, not the one that just
    about works but costs far less to make and install hence more profit.

    As one of my lecturers pointed out (IrCOm not sure I entirely agree with him)
    the point of engineering is to make money. If what you design doesnrCOt do >> that then it may be great art or great something else, but itrCOs not good >> engineering.

    Sam


    Scientific deep space probes employ some rather brilliant engineering, but they certainly donrCOt make money. Good engineering might reduce the losses. Even thatrCOs not a certainty, because missions that survive beyond the planned lifetime often get extended, with additional costs for ground support.

    ThatrCOs one of the ways IrCOm not sure I agreed with him, but if you want to add a rCLwithin scope and within budgetrCY clause IrCOd be happy with that.

    Sam
    --
    The entity formerly known as Sam.Wilson@ed.ac.uk
    Spit the dummy to reply
    --- Synchronet 3.21a-Linux NewsLink 1.2
  • From Recliner@recliner.usenet@gmail.com to uk.railway,uk.transport.london on Fri Oct 31 16:21:45 2025
    From Newsgroup: uk.transport.london

    <boltar@caprica.universe> wrote:
    On Fri, 31 Oct 2025 11:42:09 GMT
    Recliner <recliner.usenet@gmail.com> gabbled:
    <boltar@caprica.universe> wrote:
    You still havenrCOt explained how distances will be measured along the
    tunnel
    using your ridiculous idea.

    Ok, just for your geriatric brain:

    | | -- = wire
    |---F1---| | = track
    | | F = frequency
    |---F2---|
    | |
    |---F1---|
    | |

    Is that simply enough or do you need it done in crayon with help from Big >> Ted?


    Please describe how this would work over a length of several hundred
    metres, providing precise positional information to the train to within a
    few cm, every 25m. Note that you canrCOt have a power supply, junctions or >> any electronic components in the four foot.

    I can't tell if you're genuinely this thick or you're just trolling. I'll be kind and assume the latter.


    IrCOm sorry, but simply have no idea how your hare brain scheme is supposed
    to work. Your ASCII diagram gives no clue, which suggests that yourCOre clueless about it.

    --- Synchronet 3.21a-Linux NewsLink 1.2
  • From boltar@boltar@caprica.universe to uk.railway,uk.transport.london on Fri Oct 31 16:33:11 2025
    From Newsgroup: uk.transport.london

    On Fri, 31 Oct 2025 16:21:45 GMT
    Recliner <recliner.usenet@gmail.com> gabbled:
    <boltar@caprica.universe> wrote:
    Ok, just for your geriatric brain:

    | | -- = wire
    |---F1---| | = track
    | | F = frequency
    |---F2---|
    | |
    |---F1---|
    | |

    Is that simply enough or do you need it done in crayon with help from Big >>> Ted?


    Please describe how this would work over a length of several hundred
    metres, providing precise positional information to the train to within a >>> few cm, every 25m. Note that you canrCOt have a power supply, junctions or >>> any electronic components in the four foot.

    I can't tell if you're genuinely this thick or you're just trolling. I'll be >> kind and assume the latter.


    IrCOm sorry, but simply have no idea how your hare brain scheme is supposed >to work. Your ASCII diagram gives no clue, which suggests that yourCOre >clueless about it.

    Fucking hell, you really are on the senile bus arn't you. When you've arrived at Muppet Central go have a lie down and think about how alternating frequencies being picked up from wires spaced at regular known intervals might help with knowing position and speed.

    --- Synchronet 3.21a-Linux NewsLink 1.2
  • From Recliner@recliner.usenet@gmail.com to uk.railway,uk.transport.london on Fri Oct 31 16:55:27 2025
    From Newsgroup: uk.transport.london

    <boltar@caprica.universe> wrote:
    On Fri, 31 Oct 2025 16:21:45 GMT
    Recliner <recliner.usenet@gmail.com> gabbled:
    <boltar@caprica.universe> wrote:
    Ok, just for your geriatric brain:

    | | -- = wire
    |---F1---| | = track
    | | F = frequency
    |---F2---|
    | |
    |---F1---|
    | |

    Is that simply enough or do you need it done in crayon with help from Big >>>> Ted?


    Please describe how this would work over a length of several hundred
    metres, providing precise positional information to the train to within a >>>> few cm, every 25m. Note that you canrCOt have a power supply, junctions or >>>> any electronic components in the four foot.

    I can't tell if you're genuinely this thick or you're just trolling. I'll be
    kind and assume the latter.


    IrCOm sorry, but simply have no idea how your hare brain scheme is supposed >> to work. Your ASCII diagram gives no clue, which suggests that yourCOre
    clueless about it.

    Fucking hell, you really are on the senile bus arn't you. When you've arrived at Muppet Central go have a lie down and think about how alternating frequencies being picked up from wires spaced at regular known intervals might
    help with knowing position and speed.

    Both wires will in any case have to follow the track, so how would you
    ensure the wrong signal isnrCOt detected, particularly when the tracks are running side-by-side? ItrCOs also not fail-safe, as no signal will be picked up for most of the time. And the wires canrCOt also be used to communicate
    with the train.

    So your system would be much more expensive, less safe and much less functional. Truly a work of genius!

    --- Synchronet 3.21a-Linux NewsLink 1.2
  • From boltar@boltar@caprica.universe to uk.railway,uk.transport.london on Sat Nov 1 16:33:56 2025
    From Newsgroup: uk.transport.london

    On Fri, 31 Oct 2025 16:55:27 GMT
    Recliner <recliner.usenet@gmail.com> gabbled:
    <boltar@caprica.universe> wrote:
    Fucking hell, you really are on the senile bus arn't you. When you've arrived

    at Muppet Central go have a lie down and think about how alternating
    frequencies being picked up from wires spaced at regular known intervals >might
    help with knowing position and speed.

    Both wires will in any case have to follow the track, so how would you
    ensure the wrong signal isnrCOt detected, particularly when the tracks are >running side-by-side? ItrCOs also not fail-safe, as no signal will be picked >up for most of the time. And the wires canrCOt also be used to communicate >with the train.

    Huh? You'd have a detector mounted in the middle of a bogie widthways which would pick up the signals. Wouldn't matter if it picked up low level signals from the wires by the side, it would have a trigger level below which it
    would ignore anything. And so what if no signal is picked up for the majority of the time? You'd have a timeout based on the speed beyond which the emergency brakes would be applied. I'm fairly sure thats how some wireless RF ATO systems work.

    As for not being able to use the wires for communication, you think there couldn't be a third modulated frequency on one or both of the wires to do
    just that? Signal mixing has been a stable of cable and RF systems for 60
    years or more.

    So your system would be much more expensive, less safe and much less >functional. Truly a work of genius!

    Given you don't even seem to understand basic principles of signalling I'm
    not sure you're the right person to comment.

    --- Synchronet 3.21a-Linux NewsLink 1.2
  • From Recliner@recliner.usenet@gmail.com to uk.railway,uk.transport.london on Sat Nov 1 17:07:46 2025
    From Newsgroup: uk.transport.london

    <boltar@caprica.universe> wrote:
    On Fri, 31 Oct 2025 16:55:27 GMT
    Recliner <recliner.usenet@gmail.com> gabbled:
    <boltar@caprica.universe> wrote:
    Fucking hell, you really are on the senile bus arn't you. When you've arrived

    at Muppet Central go have a lie down and think about how alternating
    frequencies being picked up from wires spaced at regular known intervals
    might
    help with knowing position and speed.

    Both wires will in any case have to follow the track, so how would you
    ensure the wrong signal isnrCOt detected, particularly when the tracks are >> running side-by-side? ItrCOs also not fail-safe, as no signal will be picked
    up for most of the time. And the wires canrCOt also be used to communicate >> with the train.

    Huh? You'd have a detector mounted in the middle of a bogie widthways which would pick up the signals. Wouldn't matter if it picked up low level signals from the wires by the side, it would have a trigger level below which it would ignore anything. And so what if no signal is picked up for the majority of the time? You'd have a timeout based on the speed beyond which the emergency
    brakes would be applied. I'm fairly sure thats how some wireless RF ATO systems work.

    As for not being able to use the wires for communication, you think there couldn't be a third modulated frequency on one or both of the wires to do just that? Signal mixing has been a stable of cable and RF systems for 60 years or more.

    You really are completely clueless, arenrCOt you? CanrCOt you see that your proposal simply wouldnrCOt work at all? ItrCOs not just a rCypoorrCO solution; itrCOs a completely unworkable one. I must admit, I thought even you could do better than this.


    So your system would be much more expensive, less safe and much less
    functional. Truly a work of genius!

    Given you don't even seem to understand basic principles of signalling I'm not sure you're the right person to comment.


    ItrCOs true that IrCOm not a specialist signalling engineer, just as itrCOs obvious that that you know about 1% as much I do on this topic.

    --- Synchronet 3.21a-Linux NewsLink 1.2
  • From boltar@boltar@caprica.universe to uk.railway,uk.transport.london on Mon Nov 3 09:39:30 2025
    From Newsgroup: uk.transport.london

    On Sat, 01 Nov 2025 17:07:46 GMT
    Recliner <recliner.usenet@gmail.com> gabbled:
    <boltar@caprica.universe> wrote:
    As for not being able to use the wires for communication, you think there
    couldn't be a third modulated frequency on one or both of the wires to do >> just that? Signal mixing has been a stable of cable and RF systems for 60
    years or more.

    You really are completely clueless, arenrCOt you? CanrCOt you see that your >proposal simply wouldnrCOt work at all? ItrCOs not just a rCypoorrCO solution;


    Ah, your usual bluster when you've been caught out.

    Do explain why it wouldn't work, give specific reasons.

    Given you don't even seem to understand basic principles of signalling I'm >> not sure you're the right person to comment.


    ItrCOs true that IrCOm not a specialist signalling engineer, just as itrCOs >obvious that that you know about 1% as much I do on this topic.

    Well 1% of zero is still zero so I guess we're even.

    --- Synchronet 3.21a-Linux NewsLink 1.2