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Standard User deleted
(deleted) Wed 04-Jan-12 16:31:48
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Re: Noisy Line?


[re: deleted] [link to this post]
 
I've left it a few days so thought i'd check the connection

Comedy SNR

I need to go through the logfile but it's not a specific time, but generall in the 5pm->6:30pm SNR increases and 9am drops, neither of which tie into anything on a time in the premises.

I suspect this is either effecting the whole estate, or could just be something on this pair.

tbh it's time i probably involved Zen / BT to get them to investigate. But given they have no minimum's or sla's it's going to be a nightmare.
Standard User ukhardy07
(committed) Wed 04-Jan-12 17:05:55
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Re: Noisy Line?


[re: deleted] [link to this post]
 
That is some REIN there! Never seen anything quite so drastic.

In my household I had some massive issues. Turned out a neighbour was building a plane in his garage. Whenever he started work on the plane, the broadband dropped and synod slower... Turned out the BT lines ran underground below where he was working & his equipment was interfering.

He didn't stop though, but now the planes finished the broad bands great again.
Administrator MrSaffron
(staff) Wed 04-Jan-12 17:15:28
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Re: Noisy Line?


[re: ukhardy07] [link to this post]
 
The steps are fairly well apart, so suggests its not constant, but maybe something switching off/on

I would monitor and when all the christmas lights are down in the area, talk to neighbours and see if they have similar issues. If so, then easier to get investigations going, with co-operative neighbours you might be able to identify the source of noise, e.g. new security light, treadmill, flourescent light, LV lighting.

An AM radio at around 600kHz tuned off a station can be a good tool for hunting down RF noise sources, and also a bin plot from the ADSL modem, to see at what frequencies the noise is most prevalent.

Andrew Ferguson, [email protected]
www.thinkbroadband.com - formerly known as ADSLguide.org.uk
The author of the above post is a thinkbroadband staff member. It may not constitute an official statement on behalf of thinkbroadband.


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Standard User deleted
(deleted) Thu 05-Jan-12 10:36:38
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Re: Noisy Line?


[re: deleted] [link to this post]
 
That is such a regular pattern it's got to be a timed source - my bet would be central heating or christmas lights.

Get out in the street and look for the set that come on at 5pm and stay on all night.
Standard User deleted
(deleted) Thu 05-Jan-12 13:03:31
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Re: Noisy Line?


[re: MrSaffron] [link to this post]
 
I thought i'd post a ADSL Spectrum from the Draytek.

ADSLSpectrum

for reference, 4.8Mb @ 8.5 SNR - daytime

Have some reading to do in relation to using an AM radio to find the source.

Don't forget though that the SNR is increasing during the evening not decreasing. The noise is therefore only during the day, typically when Central heating and lighting is off.

Edited by deleted (Thu 05-Jan-12 13:39:30)

Standard User MHC
(legend) Thu 05-Jan-12 13:37:04
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Re: Noisy Line?


[re: deleted] [link to this post]
 
There is not too much wrong with that ... There is just one notch at around 50 which is about 210 khz. The notch at 64 is the pilot frequency and not used for data.

Can you get a set for different SNR values.





~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~


M H C


taurus excreta cerebrum vincit
Standard User deleted
(deleted) Thu 05-Jan-12 13:40:50
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Re: Noisy Line?


[re: MHC] [link to this post]
 
Yeah, i'll check a little later this evening.

I've updated the OP as to the speed and snr value the sprectrum referenced so we can compare.
Standard User deleted
(deleted) Wed 11-Jan-12 22:36:00
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Re: Noisy Line?


[re: deleted] [link to this post]
 
Sorry for the delay in getting back to you all,

ADSL Spectrum during the evening, doesn't look much different than during the day tbh.

22.5db SNR @ 4.8Mb
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