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[burakkucat]

I've read about the bell wire, I need to have a look at that.  From memory I think we have a LJU2 Master but again I need to check - no test socket, we've certainly never had it switched out since we've been in the house.  Where would the NTE5 typically live, assuming that there was one?  Could we ask BT to fit one, presumably at a price?

In terms of vulnerability to interference, well, the junction point to the house looks about as old as the house which is, well, old.  They recently shifted our pole lines underground, so the outside line comes up from the pavement through a small grey box enclosure and then up in parallel to the mains power line (some separation, granted) up to the guttering level, then I think along to a black junction box then back down into the house.  Even then I'm not entirely sure what route it follows because there are two extensions upstairs, neither of which we use.

   Hmm . . . It does read as if your non-optimised-for-DSL-wiring is a contributory factor to your woes. If you are definite that you do not have an NTE5/A anywhere in your home, I would suggest that you contact your ISP and tell them of that non-existence. Let them know that you would like to fit a SSF (service specific faceplate) but you are currently unable to do so due to the antique wiring and sockets. Say that you would appreciate an Openreach visit to rationalise / normalise the wiring. That will then get you an NTE5/A fitted. If the engineer is in a good mood -- provide tea / coffee / chocolate biscuits / bacon sandwiches -- you might be able to persuade her / him to replace the service cable into your home to provide a direct feed to the new NTE5/A. (Thus abandoning the up / around / in / down / who-knows-where route that the existing, probably well jointed, service cable currently takes.)

[Excelsior]

Hello burakkucat.  I'm surprised this is even a possibility, I thought the internal wiring was the homeowner's responsibility? Or is it BT's up until the point of termination, hence them being persuadable to put a new socket in?  Thing is, Sky fought us tooth and nail before begrudgingly agreeing to send a new router out so I'm really not sure they'll pay for an Openreach engineer to come out "just because"?

I have however had a minor brain wave which irritatingly comes at a time when I can't immediately test it.  I'm wondering if the electronic dimmer downstairs might itself be an issue, because my wife now tells me that the lights went down and up slowly - not just on and off, which seems a little odd.  So I'm going to take the router upstairs to one of the extension points we don't use to try and get some distance on that dimmer.  I guess ultimately if the line is "infected" with interference then it might make no difference, but I thought it would be worth a try in order to eliminate possibilities.

Incidentally I apologise if I'm rambling on this thread, but I thought it might be of historical interest down the line if someone were experiencing something similar.

[Excelsior]

I'm starting to believe in Gremlins when it comes to this house, I really am...

Lol next you will be telling us a zombie Apocalypse is coming our way 

Gary

Look behind you.
It has already begun.

  MUAAHAHAHAHAHAHAH!

[burakkucat]

I thought the internal wiring was the homeowner's responsibility? Or is it BT's up until the point of termination, hence them being persuadable to put a new socket in?

All wiring and sockets prior to the network termination point (NTP) are the responsibility of Openreach. In the case of a domestic situation, the NTP is defined as an NTE5/A (or an NTE5/B).

Wiring and sockets downstream from the NTP are the customer's responsibility. Until such time as Openreach fit a recognised NTP for you, all of that wiring and all of the sockets within your home are the responsibility of Openreach.

The cost to rationalise / normalise a legacy set-up, such as currently existing in your home, will be free to you and free to your ISP (Sky). Openreach will not charge for that service because it is in their own interest to provide it. Once the work has been done and an appropriate NTP is fitted (an NTE5/A, in this case), it frees them of all responsibility of whatever may be connected downstream of the NTP.

It is surprising how many ISPs and their respective customers that are unaware of the above facts.

Please feel free to show Sky a copy of this posting. 

[Excelsior]

Well I'll be.  I'd better make bloomin' sure there isn't another socket lurking somewhere then, although I can't imagine there can be.  When did NTE5s become the norm?  I'm not sure I've ever had a test socket, anywhere.  I'm sure it will be an old(ish) installation.  But maybe I still need to bottom out the source of this interference, otherwise a new socket may not make much odds.  I was familiar with the concept of them being responsible up to the point the line hits the interior, but had no idea there was a minimum standard of termination required.  Learn something new every day...

Back on the original topic, if there is interference on the line, why does only my downstream noise get impacted?  The upstream figure remains stable...

[coolsnakeman]

100% agree with BK. Cause you have no test point to isolate internal wiring then it is OR obligation to come out and fix your wiring up to standards free of charge. Your line provider can get this engineer arranged for you all you got to do is ring up and ask. They may advise of charges but don't worry about that you will only be charged if you have taken a hammer to BT's network and destroyed your excisting socket or gone rampage on the actually line with a flame thrower or perhaps a sawn off shotgun  Other than that you will get the socket upgraded and wiring upgraded all free of charge 

Gary

[burakkucat]

Back on the original topic, if there is interference on the line, why does only my downstream noise get impacted?  The upstream figure remains stable...

Ah, that's quite easy to explain.    The frequencies involved.

First of all, recall that the modulation technique used is DMT (discreet multi-tone). The total available bandwidth is split into separate tones or channels. For ADSL or ADSL2, there are 256 channels available. For ADSL2+, there are 512 channels available. Each of those channels is 4.3125 kHz wide. There are two blocks of channels defined for an ADSL service, the upstream band (US) and the downstream band (DS). The US band is lower in frequency to the DS band.

As an example, attached below, are "screen-scrapes" of the bit loading per channel for my line. I've split it into two, the lower frequency US band and the higher frequency DS band. (I have an ADSL2+ service but due to the line length, thus the attenuation and other factors, my modem/router selects ADSL2 mode. Hence 256 available channels.)

More channels are used by the DS band than the US band. (The asymmetric part of ADSL.) The DS band runs from approximately 142 kHz to 1100 kHz whereas the US band runs from approximately 26 kHz to 129 kHz (I've rounded the frequency to the nearest 1 kHz).

So, basically, the more (in terms of numbers) "higher frequencies" used the more chance to be "splatted". A higher frequency channel will tend to be attenuated more than a lower frequency one -- hence less "carrying power" (as in "staying power").

Finally, look at that notch at channel 46. That corresponds to the Droitwich transmitter, on 198 kHz in the LW broadcast band. A long wavelength signal (low frequency, LF) will propagate further than a medium wavelength or short wavelength (MF or HF) signal.

I've probably typed far too much and in a confusing fashion.    I'm sure if you look at the main Kitz site you will find a far more eloquent description. 

[Excelsior]

Caution - these images contain images telecom tinkerers may find disturbing.  I think the black line is the outside feed in. But it has yellow unconnected wires? Not the colours stated here. Then an alarm link up but also not visible outside another white line that presumably feeds the extensions upstairs. I think they're picking up the interference. What would be the most effective way to isolate them without wrecking the primary wire?  Would Openreach have a fit if they saw this?
http://via.me/-wko3ai  http://via.me/-wko4fy

[burakkucat]

Caution - these images contain images telecom tinkerers may find disturbing.  I think the black line is the outside feed in. But it has yellow unconnected wires? Not the colours stated here. Then an alarm link up but also not visible outside another white line that presumably feeds the extensions upstairs. I think they're picking up the interference. What would be the most effective way to isolate them without wrecking the primary wire?  Would Openreach have a fit if they saw this?
http://via.me/-wko3ai  http://via.me/-wko4fy

Let's work through things, step-wise. First and foremost I won't ask the questions: "Who is Andy Thomas? And why does he make is so difficult to download a copy of those two images?" because the former is best left unanswered and the latter has been achieved by some feline cunning. To prove the latter point, I attach the two images below. 

Now some clarification, please. Am I correct in assuming both images are of the same socket?

I think the black line is the outside feed in. But it has yellow unconnected wires? Not the colours stated here.

Correct, two-fold. Don't worry about the colours or the unconnected yellow wires -- it is the end of an external grade, multi-pair cable you are looking at.

Then an alarm link up but also not visible outside another white line that presumably feeds the extensions upstairs.

   Huh?. Please explain again, as b*cat has no idea what it is that you are attempting to describe. 

I think they're picking up the interference.

That is a distinct possibility. 

What would be the most effective way to isolate them without wrecking the primary wire?

No comment can possibly be made until a full understanding of the current wiring configuration is known. There's many a way to skin a donkey (deceased, as a result of old age).

Would Openreach have a fit if they saw this?

No.    Just a figurative "Big Sigh". That is a prime example of what Openreach regularly come across every working day and the wiring would be rationalised / normalised by fitting an NTE5/A in place of that existing master socket. At no cost to your ISP or yourself.

If you are determined to take the DIY route, I will need to have the above mysterious sentence translated plus further pictures of the insides of each of the other sockets. Also, I will need to have a clear description of the terminal to which each coloured wire is connected and from which cable the wire originates. 

[Excelsior]

My apologies, let me clarify.  Photo was taken on my mobile of the same socket.  Too big to attach, only other think I could do was Twitter it and use those image links.  Call it a workaround for speed!

So, black cable is outside cable.  Shiny.  We have an alarm system which can call us and allow us to tell a thief to get lost should the need arise.  This involves a cable running into this master socket.  Obviously your telepathy isn't working in this weather!  The white wire with the bell wire wrapped around it looks to be that one.  There is then a second white wire.  My best guess is that it's feeding the extension - it seems to go into the wall behind the socket because you can't see it externally (whereas you can with the alarm).

Now, the extension boxes are just that - one socket boxes connected to white wires.  One has a single wire exiting, one has two.  Just simple PCBs in them.  These are both on the first floor.  Which is, of course, where the ground floor halogens are closest too.  These are both "floating" boxes - not sockets attached to a wall.  My guess would be that the white wire from the master socket goes up to the double-wired box, which then feeds on to the final extension.  Does that seem reasonable?

At this point I am certainly minded to call in Openreach and bribe them heavily to simply kill off the extensions and keep the alarm wire in place.

Would I be correct in assuming that those extension cables are going to be an issue even if I just literally chop them off?  If I'm unlucky would I still end up with interference from the first floor?  Best to remove the problem at the master socket?

[burakkucat]

Ah, yes. Now I "see" it. Thank you for squeezing out the water, which was causing the confusion!

You can certainly perform some DIY but, of course, the alarm system is an added complication. Yet another question for you: Is it a monitored alarm system (i.e. monitored via the telephone circuit) or does it just make a call to a pre-programmed number if it, the alarm, is triggered? I suspect it is the latter case and, so, we will have no real problems.

This is what I would like you to do, please. At the master socket, make a clear identifying mark on the white sheath of the cable which you presume to be the connected to the alarm. So now we can talk about the "black", "white marked" and "white" cables. Next, identify which coloured wires, from which cable, are connected to the six screw terminals (numbered 1 to 6). Upstairs, at the "two white cables" socket note the coloured wires, from which cables and similarly the same from the "one white cable" socket.

Once you have all that information collated, please post it for my consideration. 

[Excelsior]

Hello Burakkucat, yes, your telepathy seems to be back on, the alarm box just calls us.  Not monitored.  As for further investigations - that will probably have to wait until the wife is out of the house and to be honest I really don't think she's going to let me do any more work on it!  If she gets frustrated enough I'm sure we'll end up with Openreach out and I think that would be by far the best option.  If I do something silly and kill our phone line my life will literally not be worth living!  If I do get an opportunity one evening I'll try and gather the information, if only for interest, if Openreach don't get there first!

[burakkucat]

I understand. 

Mrs E, a.k.a. "She who must be obeyed" or "'Er indoors", appears to read as a very formidable lady. I certainly wouldn't like to meet the soggy-end of her mop, out in the back entry, if she was both busy and in a bad mood! 

It is unfortunate that you do not live in my home town, for I would happily pad around and put things to rights! (Claws are so useful for manipulating a solitary wire out of a bundle.) 

[Excelsior]

Well, this is the extension box upstairs that has two wires coming out of it.  It looks... evil.  Clearly two wires feeding out from the same attachment point.  Can't be healthy from an interference point of view?  Problem is, I don't even know where this is fed from - how it's routed upstairs.  It must go near the light transformers one way or another.  Presumably the second upstairs extension feeds off this one, as it only has one cable going into it.  The mind boggles.

Had a look at the lights last night; hard to see, but probably a transformer set up and I could see a thick gray cord running towards our inside wall, assuming that's repeated then the telephone wire for the extensions must cut across them at some point.

Even if the transformers were working fine, which they may not be, I can't see how this set-up is ever going to not cause interference.  Perhaps we've just been lucky until this point not to have noticed it and chalked poor speeds up to where we are.  Very, very tempted to just try and disconnect the extension if I can't get Openreach out, but I'd need to do it at the master socket to take that wiring out of the equation?  Such a shame we don't have the test socket... 

[burakkucat]

It's not too bad, compared to some of the wiring I have seen. 

I note some botcher has previously snipped the orange-with-white-stripe wires from terminal three. Obviously the work of the previous owner of your house. 

It will be a very simple job to disconnect those two (upstairs) extension sockets. To empower you with the knowledge and confidence to achieve the required result, I shall refer you back to my posting, two ago. In particular --

This is what I would like you to do, please. At the master socket, make a clear identifying mark on the white sheath of the cable which you presume to be the connected to the alarm. So now we can talk about the "black", "white marked" and "white" cables. Next, identify which coloured wires, from which cable, are connected to the six screw terminals (numbered 1 to 6).

Let me know the wire colours, from which cable, to which screw terminal and I will provide you with a plan of action.