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[aesmith]

Latest update after BT OR attendance today.  As before we had everything in the house switched off before he arrived, and nothing plugged into the line except a phone into the test socket.   As before he tested the line and said it was all within spec for voice.  He tested for DSL and it was showing loads of FECs and a few CRCs, however he said that this due to interferences (the famous REIN) and not to a line fault.   

He had deduced this by listening with the van radio as he drove up to the house, he said he was picking it up a couple of hundred yards from the house, increasing as he approached but then stopping when he was alongside the house.   We went for a spin in his van and sure enough I could hear exactly the same harsh hum as we hear on the phone line, even 100 yards or so N of the house where there is absolutely nothing, over a hundred yards from our electric supply and even further from our phone line.   Driving slowly past the house the noise shut off as if by a switch, just exactly when he moved the gear lever into neutral, and it didn't reappear when we went round the house again.  I nipped inside and the noise on the phone line was exactly the same.

Following his visit I've done some tests plugging our appliances back in and listening with an AM radio, I can't say I'm any the wiser because just about every appliance seems to make some sort of noise.   Nothing makes that harsh humming/buzzing noise that we hear on the phone line.   So I have a few questions ..

(1) That testing with the van radio, how authoritative is that?  It seems to me that you're driving round with a bunch of potential interference sources in the van, for all I know it was a phone charger or invertor or something in the van causing it.

(2) Are there particular signatures I'm looking for in noise from appliances, and if I find these how can I tell if the signal strength is enough to upset the DSL?

Thanks,  Tony S

[Black Sheep]

Couple of points ............

1) The 'Noise' you can hear on your phone will NOT be the same 'Noise' that you hear on the radio. The REIN noise the engineer is looking for via his van radio, is well out of the phones frequency spectrum, as such the human ear won't be able to hear it .... it is high frequency.

2) As with your AM/MW radio 'telling you' there is HF noise on most electrical items you go near, it is exactly the same with the van-radio scenario. The 'Buzz' you hear on the radio could be deafening, but it does not automatically follow that this is SERVICE AFFECTING REIN. It merely points to the fact that there are 'Noisy' electrical items in the area.

The only way to tell if the noise you heard on the van-radio WAS service affecting REIN, would have been for the engineer to use the Spectrum Analyser on the Hand-Held Tester to view the ADSL/VDSL spectrum bandwidth.

The thing with REIN faulting is, it comes down to experience. So, I'm not calling the engineer here. Another thing to consider is the make-up of your cable feed ?? I had a REIN fault a few months ago that turned out to be 1.5Km of Aluminium cable causing the high amount of FEC's. The engineer who had raised the task had done everything right, and he could hear the same 'Buzzing' noise demonstrated to you today next to the EU's telegraph pole.
The SA is the only TRUE way to determine if REIN is present. You'll need a skip for all the 'Faulty' items your radio will find. 

[aesmith]

Thanks.  I understand what you mean about the noise, but it sounded the same.  Maybe what I mean is that the radio output, from the OR guys van, sounded the same as listening to our telephone line.  That let me (and him) to conclude that it was linked.   I guess technically what it was picking up was 50Hz modulation on that 612kHz frequency.

The other thing that gets me, was we were picking this up in the van to the N of the house, and there's no electrical equipment or cables for a good hundred yards in any direction in any direction.   I only have a photo from winter, so ignore the snow but this is about how far we travelled with no change in the signal.   Nearest electricity is the shed with the gable facing the camera, but there's nothing powered on there.  The house is around 50 further away, and the phone line comes down the hill in the background and enters the house at the far end to the south.

[burakkucat]

Latest update after BT OR attendance today.  As before we had everything in the house switched off before he arrived, and nothing plugged into the line except a phone into the test socket.   As before he tested the line and said it was all within spec for voice.  He tested for DSL and it was showing loads of FECs and a few CRCs, however he said that this due to interferences (the famous REIN) and not to a line fault.   

Was the visit for a noisy (audible) telephony fault or for a DSL fault? Quite simply, if it was the former and you were able to demonstrate --

I nipped inside and the noise on the phone line was exactly the same.

-- then the statement --

he tested the line and said it was all within spec for voice.

-- was wrong. An "in spec" line for a telephone service does not have any audible noise present upon it.

Puzzled. 

[aesmith]

Both really.  ISP is reporting errors on the DSL, corresponding with the time we first started hearing this buzzing on the phone line.  Openreach position appears to be that if the line is within spec for all their parameters like impedance, ac and dc balance etc etc, then the line is not faulty.  Their position appears to be that if the line tests OK in that way but still has audible noise then the noise must be an external factor.  That's what the guy was trying to demonstrate.  If the signal he was picking up hadn't stopped dead in that way, while the phone noise continued, then I might have accepted that.

Black Sheep I notice has not fully endorsed the "van radio" testing methodology.  I wonder if anyone has any comment about the detected "REIN" stopping so suddenly, as I say it was as if the switch had been thrown.   At that time we were around 40m from any electrical equipment or lines.  I'm really now pretty convinced the source of this "REIN" was within the van itself.

[burakkucat]

A spectrum analyser and a set of directional aerials appears to be called for. 

I have a small (hand sized) ICOM IC-R5 Communications Receiver that is capable of tuning to 300 kHz (and below) and will use it when attempting to trace electrical noise sources. I will do a sweep at 300 kHz, 303 kHz and 306 kHz before checking the higher harmonics of those three frequencies.

[aesmith]

As well as frequency, how does one assess magnitude?  I mean supposing a signal on the appropriate frequencies is detected, how do you determine whether this will or will not affect a line say 20m or 50m away?   I must say I find it a little odd that the first point of call isn't to measure for interference on the line, then to try and track down the source once it is known to affect the line.   The actual process seems to be the wrong way round.

[roseway]

I think it's a matter of where their responsibility lies. The only obligation Openreach have is to maintain the physical connection. Any investigations into external interference may or may not be carried out on a goodwill basis, depending on the availability of appropriate people, etc.

[Black Sheep]

I think it's a matter of where their responsibility lies. The only obligation Openreach have is to maintain the physical connection. Any investigations into external interference may or may not be carried out on a goodwill basis, depending on the availability of appropriate people, etc.

As roseway states above, OR's job is to test the 'Pair of wires' up to a particular standard. If that standard is met, then it will be due to faulty levels of interference coupling into their network that is causing REIN issues. Normal levels of interference would be rejected on a good pair of wires.

So, for example, if your pair of wires passes the tests, and an electric welder in a shed nearby is giving of REIN, then that will never be the fault of OR. Again, as Eric has pointed out and have you have experienced personally, OR as a gesture of goodwill regularly despatch a REIN-trained engineer to have a cursory glance in the hope of resolving the problem. This will generally be when our workstacks dictate, as REIN faulting is a gratis service ...... as a rule, nobody pays OR to attend REIN faults.

So with that in mind, to answer your question again, the only way you can measure the presence and magnitude of the unwanted signal is via a Spectrum Analyser connected directly to the pair of wires.

Our Hand Held Testers have a SA in-built, and below are three examples of a trace from a JDSU. The other HHT is an EXFO but I have no info on that device as I don't possess one.
Picture REIN1 is an example of a normal DSL circuit. REIN2&3 are circuits suffering from REIN. 

The slight problem with the HHT SA's is they are not good at capturing all types of REIN patterns due to their slow refresh rate. An electric fence giving of REIN would likely be missed for example.
As I mentioned earlier today, REIN training is virtually non-existant, because we can't leave a REIN source switched on for any length of period in our training rooms within the Telephone Exchanges for obvious reasons. It really is a case of 'time spent on jobs = experience in the bag'. I kinda remember that awful feeling in the pit of my stomach on the first dozen or so REIN jobs. Fish out of water, nervous, unconvincing to the EU when explaining outcomes etc etc ........ a bl00dy nightmare !! 

Can I ask how the engineer left the job ..... did he say he would keep the REIN case open, or that he would close it off ??
 

[aesmith]

So with that in mind, to answer your question again, the only way you can measure the presence and magnitude of the unwanted signal is via a Spectrum Analyser connected directly to the pair of wires.

That wasn't done. 

Can I ask how the engineer left the job ..... did he say he would keep the REIN case open, or that he would close it off ??

Not sure to be honest, he didn't specify. When the detected signal "switched off" the guy drove off after explaining to me that if noise on the line reappeared I could check with an AM radio to see if the signal was back.  At that stage neither of us had rechecked the phone line.  He came back because he thought he'd left something with us, and I told him the phone line noise was unchanged.   I have yet to see how the job's been reported to the ISP, but I've updated their ticket to make it clear that I don't think we have a conclusive result.

You, and the OR guy speak about "neighbours", but we have nobody with 1/4 mile of us, and no electric installations either.  I really can't see a nearby source of interference unless it's within our premises.   What I think I'll do at the weekend is switch the power off at the cutout and listen to the line like that.  I already know that switching off every appliance makes no difference, but let's test with the whole house and outbuildings de-energised.   If the noise disappears I can switch off at the CU, re-energise and then bring the final circuits on one at a time.  We do have some stuff around, like electric fence energiser, but nothing near the phone line.  (the electric fence is a pulse every 3 seconds, so it's signature should be readily recognisable, and it can be shut off for testing)

[burakkucat]

One other thing both Walter and I have done in the past is to listen to the line via an amplifier that presents a high impedance across the pair (thus not looping the pair and signalling to the exchange that a call is wished to be originated). It is surprising just what can be heard when the "proceed to call" tone (a.k.a. "dialling" tone) is absent.

[aesmith]

Presumably the same effect could be obtained by using one of those yellow test phones (aka "butt set", like you use to check to AC15 tones without interfering with the signalling.  I'll see whether we have one at work.

I must say I'm tempted to check at one of the many joints, to see whether the noise is any different a few hundred yards towards the exchange.  That's what OR has done on previous faults, whereas currently the seem to be focussing only on what's happening within our house.

I'm not convinced my issue is REIN at all.

[burakkucat]

Presumably the same effect could be obtained by using one of those yellow test phones (aka "butt set", like you use to check to AC15 tones without interfering with the signalling.

Yes, that would do nicely.

[tickmike]

How does your Electric supply come to your property ?, Is there a pole transformer ?.
Could be a HR joint !, can you borrow a infrared camera to look at the joints to see if any are getting hot .

[aesmith]

I'll put up a plan/map.  My feeling is that the transformer is too far from the line to be an issue, but maybe I'm wrong there.