RX SNR Margins -unusual question

[selldoor]

Hi
I am having a bad time with my internet - it has never worked great and recently decided to do something about it. I have joined my ISP forum and they are trying to help. I have installed a program to track what the router is doing and some improvements were made. Then after the Easter Bank holiday it all seemed a lot worse.
Trouble is I dont know how long the problem has been there.
Tend not to do gaming or streaming or skyping so speed doesnt really matter but having opened a can of worms I am trying to follow it through.
One suggestion is part of my wiring to the master socket is not twisted pair making it more likely to pick up interference. I am OK with that.
Please look at the attached graph showing the snr margin when the problem starts. Usually starts at the same time but has finished at odd times on four consecutive days. (wasnt on on the holiday weekend or today Saturday

The unusual question is: the graphs have a similar pattern and I was wondering if anyone had seen anything like them and had discovered what might cause it. Thoughts are some heavy machinery starting up but I am in a residential area with a few shops and only big establishment with a km is the hospital. Long shot I know but badcaps is a bigger forum than my ISP one.
and there is vast amount of knowledge out there.

[stj]

Re: RX SNR Margins -unusual question

interesting time 8.45 ish.
opening time.
any shops or schools near you ?

btw, try here:
http://forum.kitz.co.uk/index.php
it's infested with openreach engineers who know this stuff.

[diif]

Re: RX SNR Margins -unusual question

What router are you using ? Some are more sensitive to snr than others. Have you tried another ?

http://www.hmmm.ip3.co.uk/adsl-snr/

[stj]

Re: RX SNR Margins -unusual question

What router are you using ? Some are more sensitive to snr than others. Have you tried another ?

http://www.hmmm.ip3.co.uk/adsl-snr/

the DG834 is a very good router, but has a few bad caps and needs custom firmware from DGteam.

[selldoor]

Re: RX SNR Margins -unusual question

Hi thanks for the replies.
I have read a lot of kitz stuff - I think he also features on thinkbroadband.

I have not tried another router - it is a plusnet thompson TG582n which I believe has poor rep. However it has worked pretty well for 14 months
I dont have any drop outs and normally the slow speed doesnt bother me.
Its only now that I see something is bombing me I am trying to do something about it. Before that when it went really slow I just assumed it was various things updating.
Apparently this type of problem is difficult to resolve as no-one wants to take responsibilty I think it comes in the same category as REIN. ISPs say their end is ok BT say the line is ok. There is no legislation at the moment to cover it so legally no-one has to do anything.
I am pretty much scuppered as the bit of cable that joins the down wire to the masterbox - about 20 feet - is not twisted pair so it may act as aerial.
I dont want to replace it as it is behind heavy difficult to move furniture
china cabinet with hundreds of bits in, partly under a fitted carpet and it is wallpapered over for a good length.
Thing is with this problem it is so difficult to find the problem BT openreach whoever seem to want to try and make it better without stopping the problem. It could even be someone a few doors off with a dodgy dtb or skybox. Yes they are manufactured so as not to cause "noise" but if they go wrong they can work just the same and cause havoc for someone.
If it was someone broadcasting a radio signal ( basically the same thing) but it was interfering with a TV then the BBC have powers to do something about it but not interest in adsl broadband.
Anyway I am on steep learning curve with it - so maybe just quoting other peoples heresay- I knew it was a longshot but someone may have come across something similar before.
I will go back to trying to find the signal on a MW radio and then see if I can see where it comes from.Lot of trial and error! I am keeping a record of all the times and may try writing to any likely places to ask if they switch anything on regularly around those times. School is near but has been closed for half term.
At the moment a few shops in a cluster and a non nhs part of the hospital are favourite. - They are between me and my bt cabinet

[stj]

Re: RX SNR Margins -unusual question

there is some stuff about hunting electrical noise - i'll try & find it.

[stj]

Re: RX SNR Margins -unusual question

in some of these.
http://www.dkars.nl/index.php?page=magazine_uk

[diif]

Re: RX SNR Margins -unusual question

If you're not tied to your current ISP with a contract, you could leave and join BT. They then don't have anyone to shift the blame to, which is their current trick.
It might also be worth trying another router, to see if it handles the problem better.

[stj]

Re: RX SNR Margins -unusual question

if it always takes a hit at 08:45 am, when does it come back up?
the specific times will help you track it down.

[selldoor]

Re: RX SNR Margins -unusual question

in some of these.
http://www.dkars.nl/index.php?page=magazine_uk


Thanks STJ will have a read



If you're not tied to your current ISP with a contract, you could leave and join BT. They then don't have anyone to shift the blame to, which is their current trick.
It might also be worth trying another router, to see if it handles the problem better.


Currenty tied ( I think) another 4 months then I will change unless they come up with an unbeatable offer.
May even try fibre the prices seem to be converging though if its FTTC then it may not fix it if it is very localised.

if it always takes a hit at 08:45 am, when does it come back up?
the specific times will help you track it down.

Yes I started a table after day 2
DATE ..................................ON....................................OFF
Mon 6 April Bank Hol - -
Tue 7 April ......................... 08-34 .............................. 19-01
Wed 8 April ......................... 08-36............................... 17-11
Thu 9 April ........................ 08-40 ...............................12=51
Fri 10 April ....................... 08-34 ...............................16-10
Sat 11 April ok ok
Sun 12 April
Mon 13 April

[stj]

Re: RX SNR Margins -unusual question

so weekdays only.
fixed start, but not so fixed that it's an electronic timeswitch.
friday was before 5 so it's probably not a shop - probably.
thursday is interesting.
is it half day on thursday in your area?

[selldoor]

Re: RX SNR Margins -unusual question

Yes Thursday is a half day for some but I checked the shops nearby and they were all open. Favourite of the shops has to be a computer repair shop!!!
at least if that appears to be a problem area he will have some clue as to what I am talking about. I may even go in for a chat and see if he has had any problems. He will likely try to sell me anew router.

Daft as it seems I am now hoping the problem is back tomorrow so I can try a few more things. My car radio may show up the noise and as I can scan through the MW band on that it if it finds anything it will show the khz on the dial then I can go out with a portable set on that and try and find where it comes from.

Did wonder about trying some ferrite rings on the downwire if I can make loops in the wire. Think they are normally used on mains cables to stop interference from a dodgy appliance infecting the mains? might also try that on the router cable.

[stj]

Re: RX SNR Margins -unusual question

the noise could be airborne, or on the adsl or even mains - if it's on the same transformer output.
some shit may have an ancient am/fm over mains intercom or something!

[Per Hansson]

Re: RX SNR Margins -unusual question

Have you tried the obvious and disconnected everything on the phone line so you only have the two required lines to your ADSL modem and then nothing?

If so you can try the next cool thing: swap the cables around, see any improvement?
ADSL actually only uses one cable for data transmission, the other one is for canceling out the noise (twisted pair cabling)

The theory is that if only one of the two wires is affected that might get around the problem...

You say it's too difficult to put a new cable in, but you could try putting one besides it temporarily to see if it makes any difference.

[selldoor]

Re: RX SNR Margins -unusual question

Hi Per - thanks for the interest.

Have you tried the obvious and disconnected everything on the phone line so you only have the two required lines to your ADSL modem and then nothing?

Only have the one master connector connected to the down wire - no extensions. Phone is on the same outlet with a filter ( changed for test)

If so you can try the next cool thing: swap the cables around, see any improvement?
ADSL actually only uses one cable for data transmission, the other one is for canceling out the noise (twisted pair cabling)
The theory is that if only one of the two wires is affected that might get around the problem...

You mean swap the two wires that go into the master? I have not tried that
- I and the ISP cummunity forum I raised the problem with seem pretty sure it has to be external Noise. Maybe changing the wires over is something to try
but the forum gurus dont want me to change anything on the current set up.

When they get bored with it I might try that BUT there is another snag which also replies to the last point. In the UK you are not supposed to touch any wiring up to BT Master Box.
I did look at it to check the wires were in and no "spare" wires just floating about causing trouble. They are just just push in with an IDC tool at the box but where they connect
they have BT gel connectors so cant really disconnect and similarly if I cut the wires to insert a new length of cable to test I will have to re solder the old one and they are bound to notice that.
( Probably making any visit chargeable - Min £60 +vat I think)

You say it's too difficult to put a new cable in, but you could try putting one besides it temporarily to see if it makes any difference.

see above

[stj]

Re: RX SNR Margins -unusual question

legal bit.
BT are responsable for the incoming feed upto and including the master box.
after that it's your problem.