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[Ezzer]

set top boxes forgot about those, and yes i do remember a suspect aerial booster in a leaky roof space.

If you use a CAT, don't know if youve noticed the lump/bulge at the foot of the cat. Its a ferrite coil antenna. just mentioned it as knowing that it may make using a MW radio for REIN that little bit clearer. And for tracing some along d/w's its similar to a cat but using a 444 with a rods measuring. With REIN transmitted down O/H plant that really speeds things up 

Although I think its time I made a bit of a confession. When on the task where about 4-5 square kilometers where knocked out. A guy from Martlesham came up with a spectral anyliser. And another guy from london who had something to do with setting up the REIN course. He asked me a question to which my answer shocked him.

"How long ago did you do the REIN course ?" "I didn't !" 

[burakkucat]

And another guy from london who had something to do with setting up the REIN course. He asked me a question to which my answer shocked him.

"How long ago did you do the REIN course ?" "I didn't !" 

 

[razpag]

set top boxes forgot about those, and yes i do remember a suspect aerial booster in a leaky roof space.

If you use a CAT, don't know if youve noticed the lump/bulge at the foot of the cat. Its a ferrite coil antenna. just mentioned it as knowing that it may make using a MW radio for REIN that little bit clearer. And for tracing some along d/w's its similar to a cat but using a 444 with a rods measuring. With REIN transmitted down O/H plant that really speeds things up 

Although I think its time I made a bit of a confession. When on the task where about 4-5 square kilometers where knocked out. A guy from Martlesham came up with a spectral anyliser. And another guy from london who had something to do with setting up the REIN course. He asked me a question to which my answer shocked him.

"How long ago did you do the REIN course ?" "I didn't !" 

Ha ha ha ..... you're a man after my own heart Ezzer. I too have performed REIN tasks when not trained, and ended up on the REIN distribution lists !!! I used to get called approx once a month and asked to shoot off to some far distant town/city to remedy the fault. As I say, I'm now officially capable (apparently  ) of picking these types of job up.

I do indeed use the 'Cat and Genny' as part of my job, although it's getting less and less as I seem to be permanently picking BB work up. Yes, I did notice the bulge and thought it was just a poor manufacturing job. We were told on the course about the measuring rods and 444b method, thank you though for mentioning it. 

[Ezzer]

Yay, nice to hear some feedback gets through to the REIN training. Some of the guys thought I looked a loon using the rods like that.

Thats how I got on to REIN too. I was given the 444 to use after a while. used to leave it in the dsl stores cupboard in case anyone else wanted to use it. But no one wanted to touch REIN with a barge pole, so I ended up doing them all.

 

[MartinGoose]

Fascinating read for the intelligent non-specialist! I hope I qualify for this description.

In respect of my REIN fault, Openreach were back on site yesterday to investigate the particular premises that was identified before the weekend. I was not involved initially, but Openreach reported afterwards that they had located the source of the REIN. It was the power supply for a Belkin USB hub.  Once this was taken out of use my SNR margin improved by about 2 dB.

However my problems were intermittent not continuous, and the SNR drop could be 10 dB. Clearly Openreach found a fault, but I don't think it is the fault that is doing the serious damage! Time will tell.

After Openreach departed I spoke to my neighbour and we did some 'testing' of the faulty unit. We plugged it in, in my house, and used my radio on 612 kHz.  There was clear interference but the sound was entirely different to the recording I made previously and linked to above in this thread. The volume also appeared to be much lower, but this could just be a different setting on the volume control on my radio.  When I checked my Routerstats traces, I had lost 2 dB of SNR during the test.

I also looked back and saw the effect of the Openreach testing in my neighbours house earlier in the day. Temporary 2 dB gain when they switched off at the consumer unit followed by a permanent 2 dB gain when the offending item was taken out of use.

So a small step in the right direction but I await the next serious outage and further 'fun and games'!

[burakkucat]

Thank you for the update, Martin. As you say, a step in the right direction.

As the signal produced by that PSU was not identical to the "treadmill", there still is a source of intermittent REIN "out there".

Have you ensured that your ISP / CP have noted that fact in the log for this issue?

[MartinGoose]

Have you ensured that your ISP / CP have noted that fact in the log for this issue?

Oh, yes!!!

[snadge]

Im subscribing to this thread as I find it very interesting (I'm not a Specialist or anything I just find it intriguing),

one thing I want to ask though; Martin says that his SNR "drops" when the REIN is effective... I always thought SNR was 'raised' by Interference? and decreases when that Interference goes away? - is there something I'm missing?

- stating the obvious, but, judging from the Router Stats graph its obviously something thats only on during the day as SNR drops during the night and increasing from 6.5db at about 2/3am to 12db by 6am , the day before at 6/7am it was 2db less (10db) - this could be the USB hub 'off' and the "second" cause of interference on its own (then the USB Hub coming on at lunchtime which would explain the 2db spike up to 12db)

please correct me if I've said anything incorrect here as Iam still learning myself and another reason for following this thread.

[waltergmw]

Hi Snage again,

You'll see that we usually talk about signal to noise ratio and not just noise on its own.

So you can imagine the SNR as the freeboard on a boat, the more freeboard you have the better your chances of not being swamped by a large noise "wave".

Kind regards,
Walter

[snadge]

Hi Walter,

I prefer the "shouting over a noisy hall" analogy myself hehe, yeah I know what SNR Margin is etc (I actually know quite a bit about ADSL but not as much as some of these guys) I'm just saying that im confused at Martin saying:  "Yes. I have only heard the radio noise when the SNR has plunged. I have never heard the radio noise when the SNR has *not* plunged. "  Iam on the understanding that SNR 'raises' when there is interference on the line - or is he using that term meaning the line has dropped?

[razpag]

Hi Walter,

I prefer the "shouting over a noisy hall" analogy myself hehe, yeah I know what SNR Margin is etc (I actually know quite a bit about ADSL but not as much as some of these guys) I'm just saying that im confused at Martin saying:  "Yes. I have only heard the radio noise when the SNR has plunged. I have never heard the radio noise when the SNR has *not* plunged. "  Iam on the understanding that SNR 'raises' when there is interference on the line - or is he using that term meaning the line has dropped?

Take it from me Walter, Snadge knows his stuff mate. Obviously you weren't to know that though and being the gentleman that you are, offered up your wisdom.

[MartinGoose]

I'm just saying that im confused at Martin saying:  "Yes. I have only heard the radio noise when the SNR has plunged. I have never heard the radio noise when the SNR has *not* plunged. "  Iam on the understanding that SNR 'raises' when there is interference on the line - or is he using that term meaning the line has dropped?

Let me explain my use of the word plunge.  To me it means 'to go down' or 'get worse'.  To me, going down in the Routerstats display means that the SNR margin is getting smaller numerically.  If the required data signal is unchanged then the noise is getting worse and may eventually drown out the required data.

In some cases this causes the router to resync with the DSLAM at the exchange at a lower rate, effectively strengthening the required data signal and improving (making numerically larger) the SNR margin.

In other cases the router does not resync and the required data is indistinguishable from the noise on arrival and has to be retransmitted over and over again.  This leads to download speeds (more correctly called bandwidth) of uncorrupted data to drop dramatically and the connection effectively becomes unusable.

I hope that I have that right!

[jeffbb]

Hi
quote @ Snadge : I always thought SNR was 'raised' by Interference? and decreases when that Interference goes away? - is there something I'm missing?
Not quite right

SNR Signal to noise ratio that is the total ratio between the noise baseline and the signal level  The LARGER the Better .
Routers  normally display SNR margin ,the default is 6db(the target set for stability) on a good quality line . So if a line has an SNR of 50db then then there is 44db available for data .

If suddenly noise increases on the line say by 3db then your SNR margin will drop by 3db . So if you see a gradual or sudden drop in SNR margin then it is caused by gradual or sudden increase in noise . The opposite is also true if your SNR margin increases the the line conditions are improving .
Regards Jeff
 

[snadge]

ahh right... i see what iam missing now...lol - where raising the SNR Margin just keeps the 'margin' at 6db regardless and does help to keep the line stable (even with less speed) but it doesnt hide from the fact that noise has increased on the line and a shrinking margin would reveal that happening...  you know, ive been helping others on broadband forums for years now and im still learning basics like that ...sheesh..

thanks for clearing that up Jeff, much appreciated

[razpag]

LOL Snadge.

You're not on your own bud. I have to gen up on certain info from time-to-time (like SNR Margins), just to put the correct info back into my brain. As I learn new stuff, things like that seem to dissapear to the back of my tempal lobes. JeffBB is the man when it comes to SNR though.