Unresolved support ticket open for more than six months - is this a record?

[#1]

is that from all the people on this thread helping Mal? 
It could be Harmonics of a Crappy airline, I live a fair distane from Stansted, on the outer limit of one of the\controlled take of routes, I find that Ryan Air and only them blot out my reasonable quality radio and I get clear speech.  There are also Airport information and Weather reports broadcast at the lower end of the FM Spectrum from the airport, and possible as AM broadcast.

[#2]

Quote from: mal0z

Is it: ... --- ...   ... --- ...   ... --- ...

Sometimes, but I've been seeing more of this pattern recently 
... -. .- ..-. ..-
Still crawling along at 192kbps and noise margin is now 31.4Db - I wonder if BT would respond better if I asked for help using morse code? Latest DMT graph is as grim as last night's...
Going out for a while, but will check back later this afternoon.

[#3]

I tell you what's really odd about that is that the upstream graph isn't too bad, but at the transition it just flatlines.
That suggests it's more likely something specific to the downstream, i.e. equipment on the end of the line rather than anything in between or interference.
Or it could be interference that's very local to you and doesn't propagate to the exchange down the line.
To save going back over this huge thread, have you tried another router recently? You really ought to have one to hand, even if it's just an old USB job.

[#4]

I'm sure the answer is within grasp now....
Can you record the sounds from the radio as evidence for BT and upload them somewhere we can listen to them.
Can you then do a walk test with each frequency you heard in turn. Where is it loudest? Near any equipment? Does it get quieter anywhere? Is it the same volume outside your house? Up in the loft? At you neighbours house? Near the street cabinets you mentioned?
I hopeful the radio will help you find the culprit if it is in your house, OR give you enough evidence to prove to BT it is on your ADSL line itself, OR prove it is airbourne outside and needing OFCOM to investigate!
I'm hopeful that this noise means the cause is much closer now.
Mike

[#5]

But do Ofcomm have a remit to investigate interference to ADSL ?.
I'm not sure they do, only TV , broadcast radio and of course interference to public radio systems like emergency services, military and unlicensed radio transmitters.
I would like to shown I'm wrong - but I fear not ?

[#6]

Mal,
If you can hear the frequencies clearly airbourne on your radio, would they have to investigate (you don't even need to mention ADSL). Hypothetical anyway, as the walk test might prove the source to be in the house, or on the line. If it is airbourne, there is still the question of why it is affecting the OP, and not the neighbour... so still potentially possible to resolve locally, by router positioning, adding some shielding etc.
I think the airbourne option is the least likely, so we would only have to cross that bridge if it came up as the scenario. I'd like to think that OFCOM could be coerced into action if required, because ADSL is a valid use of those frequencies, so if it really was an airbourne frequency that was affecting them, then hopefully it could be argued that they should investigate it's source. Equally BT could also be coerced to investigate an airbourne source, even if only to provide some sort of shielding to isolate it.
I suspect that it is most likely to be in the house if it is clear on the radio, unless it is only heard near the router, or phoneline in which case it is probably line bound, since OP has tried multiple routers already.
Did the earth problem get fully sorted yet? Or is that still waiting the electrician to do the next phase?

Mike

[#7]

Mike - to be honest , I'm not 100% up to speed on the Ofcomm rules these days - and even in some companies ( even very large ones ) some staff aren't either. But an email or call to them might be a good idea for the OP. I can't vouce for them now, but when I dealt with the investigation people a number of years ago, they were very good and helpful. If we had interference and plotted it on a spectrum anylyser - and reported it, they would get on to their monitoring stations and triangulate it and tell us it was a ship, oil rig, station on land and they would even tell us the exact frequency accurate to one herz and the effetive power output !!!.
But I agree - that as it is not effecting the neighbour - it is unlikely to be the cause of this problem - as presumably their lines go down the same multipair cable to the exchange.
One solution - is for the OP to search out his local amateur radio club, as they have some knowledgeable people with direction finding radios and they may be interesting in helping just as an exercise ?.

[#8]

I know this sounds stupid, but,
Have you tried fitting an i-plate or disconnecting the bell wire?
I had a weird problem where every time someone picked up a phone, my noise margin went down by 6dB (and recovered when they came off the phone)
I'm guessing that I was getting some kind of strange earth loop problem????
The i-plate fixed it - it filters the bell wire.

[#9]

Quote from: Catweazle

... found various degrees of buzzing at the following (approximate) frequencies 520, 600, 650, 710, 790 (this one sounds more like very rapid morse code), 990.

The bit about morse reminded me - beacons for aircraft navigation usually transmit their identity in morse code, modulated on top of their normal frequency.
http://en.wikipedia.org/wiki/Non-directional_beacon
However, that link implies their frequency would be in the range of 280 - 530 kHz.
This link shows Gatwick has 2 NDBs on frequencies of 338 and 365 kHz.
http://www.pilotfriend.com/flightplanning/flight%20planning/uk_navaids3.htm
They're shown on the map at the front of this PDF:
http://www.caa.co.uk/docs/299/DAP_ACD_HeathGat.pdf
As others say though - these would be affecting the neighbours too.

[#10]

The frequencies of the transmitters don't have to be the frequency to affect you. They can be harmonics, or two transmitters together interfering, because of what is called intermodulation - and I I may have said either earlier in this thread or another - it could be what is known as a "rusty bolt", which acts as a non-linear devise and could be any nearby metals objects which are not bonded to each other properly.
But the two or more transmitters and or the badly bonded conductive elements would need to fairly close to you. So we are back to a poorly bonded earth on the premises perhaps ?.
Tracking down radio Interference is quite challenging and potentially expensive - and then determining whose fault is is can be even more of a problems.
http://www.ofcom.org.uk/complain/inter/radio/293505/?itemid=300133
http://www.ofcom.org.uk/radiocomms/ifi/enforcement/br

[#11]

going back several years the radio tracking service was deregulated and the only one that they would look at are to the licensed channels, i.e. Radio (BBC Etc) and Television, they were no interested in either CB or Ham Radio any more, and dont seem to be very interested in stopping Pirate radio now either

[#12]

Post Office it was - a prime receiving station at Baldock that we phoned  IIRC

[#13]

Quote from: HPsauce

I tell you what's really odd about that is that the upstream graph isn't too bad, but at the transition it just flatlines.

Something even odder about the graph is the text next to it - where it lists the statistics.
Note that there are NO errors whatsoever. Over 13 hours.
If interference was the primary problem (during those 13 hours), then surely we'd be seeing some errors? Something in the RSCorr especially, but also RSUnCorr, HEC, ES, SES or CRC fields.
With an SNRM of 31.4 shown, it looks like the modem (or DSLAM) has pulled back to giving the barest minimal service, even in the absence of interference.
Can the DSLAM be set to do that - either through its automatic monitoring, or through manual O&M?
Or is this a sign that the modem might be having problems?
Mike

[#14]

No, I think that whatever causes the problem is transient (or even just at sync time).
So, when running, as has been seen before, there are no errors as the SNRM is huge.
When the SNRM is that high, and it's been running like that for a while, a resync is called for I think.
I also think rather than speculate about morse code from wherever we should wait until Catweazle and/or BT provide more information. Remember the neighbours are fine.

[#15]

Perhaps the neighbour has a giant white noise generator.