Router Interference causing DSL resync?

Hi Folks,

I've been battling with an issue for about 10 to 12 weeks now, and
cannot get to the bottom of it. I'm totally sick of it now!!

I have an ADSL2+ connection from Be* (Upto 24Mbps) - by default they
supply a Thomson Speedtouch 780 router.
Also by default they put you on a 6dB SNR profile with Interleaving.

About 3 or 4 times a day the DSL signal would drop causing the router
to resync with the exchange.
I've logged the times and it ALWAYS happens during the daytime - from
what I can see, it never happens between 9pm and 7am.

Over the past couple of months, I have tried the following:-

Adjust SNR from 6dB to 9dB and 12dB - no change

Purchased a Netgear DG834N - same problem with this router

Eliminated extension sockets, and run from master socket with
faceplate removed - no change

Monitored connection with 'DMT' tool - interesting finding!

The interesting finding is that periodically the router gets a blast
of noise at about 1700KHz, which drops the SNR by -20dB (at about that
1700KHz frequency).

It has been suggested that something like EMI from a fridge, freezer,
central heating, fairy lights, AC to DC transformers, possible HAM
radio or old analogue cordless phones in the vicinity could cause
this.

I've been to all neigbours houses - they all have either DECT phones
or standard phones plugged into the wall sockets.
I even switched off all electricity in the house for 24 hours, and ran
an extension cable from neighbours garage to the PC and Router (yes..
I know running extension between building is a no-no, but I was at
wits end!) - anyway - the router still reset itself, so I've ruled out
my central heating, fridge, freezer, microwave and every other
electric device in my house.

Could anyone please advise anything else that's causing this problem??
Has anyone seen or heared of anything like this before??

I've had the call open with the ISP for 10 or 12 weeks now, but they
don't seem to think this is a line problem.. Keep telling me it's a
"local issue"..

Any help or tips gratefully appreciated.

Regards

Steve

(E-Mail Removed) wrote:
> Hi Folks,
>
> I've been battling with an issue for about 10 to 12 weeks
> now, and cannot get to the bottom of it. I'm totally
> sick of it now!!
>
> I have an ADSL2+ connection from Be* (Upto 24Mbps) - by
> default they supply a Thomson Speedtouch 780 router.
> Also by default they put you on a 6dB SNR profile with
> Interleaving.
>
> About 3 or 4 times a day the DSL signal would drop
> causing the router to resync with the exchange.
> I've logged the times and it ALWAYS happens during the
> daytime - from what I can see, it never happens between
> 9pm and 7am.
>
> Over the past couple of months, I have tried the
> following:-
>
> Adjust SNR from 6dB to 9dB and 12dB - no change
>
> Purchased a Netgear DG834N - same problem with this router
>
> Eliminated extension sockets, and run from master socket
> with faceplate removed - no change
>
> Monitored connection with 'DMT' tool - interesting
> finding!
>
> The interesting finding is that periodically the router
> gets a blast of noise at about 1700KHz, which drops the
> SNR by -20dB (at about that 1700KHz frequency).
>
> It has been suggested that something like EMI from a
> fridge, freezer, central heating, fairy lights, AC to DC
> transformers, possible HAM radio or old analogue cordless
> phones in the vicinity could cause this.
>
> I've been to all neigbours houses - they all have either
> DECT phones or standard phones plugged into the wall
> sockets.
> I even switched off all electricity in the house for 24
> hours, and ran an extension cable from neighbours garage
> to the PC and Router (yes.. I know running extension
> between building is a no-no, but I was at wits end!) -
> anyway - the router still reset itself, so I've ruled out
> my central heating, fridge, freezer, microwave and every
> other electric device in my house.
>
> Could anyone please advise anything else that's causing
> this problem?? Has anyone seen or heared of anything like
> this before??
>
> I've had the call open with the ISP for 10 or 12 weeks
> now, but they don't seem to think this is a line
> problem.. Keep telling me it's a "local issue"..
>
> Any help or tips gratefully appreciated.
>
> Regards
>
> Steve

Could be anything electrical in a house along the line of route of
your telephone line. It's been known for a such problems to be caused
by faulty equipment upto a mile away (so far) & I wouldn't say that is
the maximum distance.

Get yourself a AM radio tune it to radio 5 (easy to find) or 612Khz
(not 1700khz) & just keep your ears open as you move around your
neighbour & you find the source but won't have a leg to stand on if
you do as DSL is not a protected service.

Try & get Be to raise a REIN fault with BT wholesale they will have a
better chance of finding it, but as already said it's not a protected
service (that's one of the reasons for using radio 5 as that is) & the
engineer will have to negotiate with who ever is causing the problem
to see if it can be resolved to everybodies satisfaction.

Got an ongoing case quite near me, I found it (the problem) around a
month before I was sent out to it (some of us have a habit of driving
around listen to the ambient RF on 612khz, I know it's sad). Have
(hopefully) traced it to a house but they are refusing to get in
contact so there is little we can do at this point.

But check your house out first, yes I know you've run everything from
your neighbours house BUT you used the same power supply for the
router (this is where the AM radio comes into play) have a listen with
the radio quite close to the power supply & also close to the
telephone wiring, you may get a nasty shock..

Kraftee,
Thank you very much for your post. Sad as it is, I had been out with
the car on AM frequency just 1650? or so just before end of AM band
cuts off.. obviously barking up wrong tree.. but shows the length
we'll go to !

BTW - here's a link to the DMT stats when that 1700Khz blast was
picked up:

http://mychestnut.files.wordpress.co...dmt-180207.JPG



On Mon, 26 Mar 2007 22:59:35 +0100, "kraftee"
<Kraftee@b&e-cottee.me.uk> wrote:

>Could be anything electrical in a house along the line of route of
>your telephone line. It's been known for a such problems to be caused
>by faulty equipment upto a mile away (so far) & I wouldn't say that is
>the maximum distance.

Despite the <800m as crow flies, my cable length is nearer 1.8KM
so it's defintely going around the housing estate before going to
exchange.
BT OpenReach came in before Christmas when I was on 8Mbps ADSL Max
because of another issue, and reported I was *direct* to exchange
without going through any cabs. But I know there's a series of
manholes and plenty of cabling past houses (all underground) before
getting to the exchange.


>
>Get yourself a AM radio tune it to radio 5 (easy to find) or 612Khz
>(not 1700khz) & just keep your ears open as you move around your
>neighbour & you find the source but won't have a leg to stand on if
>you do as DSL is not a protected service.

If the EMI (assuming it is EMI) is blowing away the 1700KHz range, do
you think the AM radio at 612Khz will pick this up??? - I understand
the reasoning for Radio 5 / protected service, but will I actually be
able to hear the "noise" at this frequency?

>
>Try & get Be to raise a REIN fault with BT wholesale they will have a
>better chance of finding it

OK.. I'll do the Radio AM check first, before doing this as it sounds
like a one way ticket!
>
>Got an ongoing case quite near me, I found it (the problem) around a
>month before I was sent out to it (some of us have a habit of driving
>around listen to the ambient RF on 612khz, I know it's sad). Have
>(hopefully) traced it to a house but they are refusing to get in
>contact so there is little we can do at this point.

That is annoying..I could take 6 months or more to find this, and then
not be able to do anything. makes you want to *burn* the culprit !!
LOL


>
>But check your house out first, yes I know you've run everything from
>your neighbours house BUT you used the same power supply for the
>router (this is where the AM radio comes into play) have a listen with
>the radio quite close to the power supply & also close to the
>telephone wiring, you may get a nasty shock..
>
OK.. Thanks again.. Please clarify that you think the 1700KHz signal
should be picked up by AM radio on 612Khz, and I'll go and find
someone with an old radio so I can do this. I guess the 1700Khz
picked up by the router with 20dB is ***strong*** so most AM band
would pick it up??

Cheers

Steve

(E-Mail Removed) wrote on Mon, 26 Mar 2007 at 23:31:55:
>BTW - here's a link to the DMT stats when that 1700Khz blast was picked
>up:
>
>http://mychestnut.files.wordpress.co...dmt-180207.JPG

A quick sanity check. Why does the 3rd graph have a time axis, even
though the plotted points seem to line up with the downstream tones?

HTH,
--
Tony

On Tue, 27 Mar 2007 08:07:29 +0100, Tony
<(E-Mail Removed)> wrote:


>A quick sanity check. Why does the 3rd graph have a time axis, even
>though the plotted points seem to line up with the downstream tones?
>
Hi Tony,
A very valid point there.
That time axis doesn't seem to indicate anything as far as i can see.
As the times it shows were not relevant to the actual time period the
monitoring was running!!
I'd posted the link to that screen shot on the Bethere forum and
quite a few people seem to think / agree that ~1700KHz is the
frequency of the unwanted noise though, so I'm just ignoring that time
axis.

The more I look into this (other than being totally sick of it now!)
is making me think AM radio is only way to go. Perhaps I can't rely
on the info portrayed in that graph??

Steve

SteveC wrote:
> On Tue, 27 Mar 2007 08:07:29 +0100, Tony
> <(E-Mail Removed)> wrote:
>
>
>>A quick sanity check. Why does the 3rd graph have a time
>>axis, even though the plotted points seem to line up with
>>the downstream tones?
>>
> Hi Tony,
> A very valid point there.
> That time axis doesn't seem to indicate anything as far
> as i can see. As the times it shows were not relevant to
> the actual time period the monitoring was running!!
> I'd posted the link to that screen shot on the Bethere
> forum and quite a few people seem to think / agree that
> ~1700KHz is the frequency of the unwanted noise though,
> so I'm just ignoring that time axis.
>
> The more I look into this (other than being totally sick
> of it now!) is making me think AM radio is only way to
> go. Perhaps I can't rely on the info portrayed in that
> graph??

The 1700knz could be a third harmonic of the actual problem signal so
don't get to worried about that. 612khz is the frequency which the BT
REIN Investigator has been told (trained, if you can call it that,
informed is more like it) to use & by the the time you put the fudge
factor in 1700 is not that far away. Remember the AM radio is useful,
specially around your house, but if you do find a likely candidate in
another property you won't be able to do anything about it.

The only way forward is to check your house (remember it's anything
electrical, yep even those wonderful super efficient light bulbs have
been known to cause problems) so just wander around the house with
your ears open. If you've got a friend who is an amateur radio
licencee ask to see if he has got an RF sniffer which you could borrow
(hell he'll most probably try & help as it would pique his interest).
If you've got a BT field engineer as a friend beg, borrow (well steal
really) an RF3 filter to fit on your line, just in case the signal
really is at 1700khz. In other words do everything you can to help
yourself but also keep on a Be to get it it passed to BT
Wholesale ------> Openreach as it may be a local problem but if it's
outside your property how the hell are you supposed to fix it?

On Mar 26, 5:59 pm, "kraftee" <Kraftee@b&e-cottee.me.uk> wrote:
> Get yourself a AM radio tune it to radio 5 (easy to find) or 612Khz
> (not 1700khz) & just keep your ears open as you move around your
> neighbour & ...

What is the significance of 612 Khz? Why that frequency?

w_tom wrote:
> On Mar 26, 5:59 pm, "kraftee" <Kraftee@b&e-cottee.me.uk>
> wrote:
>> Get yourself a AM radio tune it to radio 5 (easy to
>> find) or 612Khz (not 1700khz) & just keep your ears open
>> as you move around your neighbour & ...
>
> What is the significance of 612 Khz? Why that frequency?

Don't ask where abouts it is on the ADSL set of frequencies but that
is the one the REIN SFI desk will tell you to check on & it's the one
which I was told to use on the one day 'training' event which they
gave before throwing the RF sniffer at us before telling us to go &
play. We used to have a crude RR Spectrometer in one of the test
packages we used, it was never supported & it was withdrawn on a later
release.

So it boils down to I was told to use it & it hasn't been proved
incorrect _yet_ .

On 2007-03-28, w_tom <(E-Mail Removed)> wrote:
> On Mar 26, 5:59 pm, "kraftee" <Kraftee@b&e-cottee.me.uk> wrote:
>> Get yourself a AM radio tune it to radio 5 (easy to find) or 612Khz
>> (not 1700khz) & just keep your ears open as you move around your
>> neighbour & ...
>
> What is the significance of 612 Khz? Why that frequency?

The most common downstream ADSL frequency band is 138 kHz to 1104 kHz.
612 kHz is pretty close to the center of it, so if you had to pick
one frequency to listen to that wouldn't be a bad choice.

Dennis Ferguson

On Wed, 28 Mar 2007 17:52:54 -0500, Dennis Ferguson
<(E-Mail Removed)> wrote:

>On 2007-03-28, w_tom <(E-Mail Removed)> wrote:
>> On Mar 26, 5:59 pm, "kraftee" <Kraftee@b&e-cottee.me.uk> wrote:
>>> Get yourself a AM radio tune it to radio 5 (easy to find) or 612Khz
>>> (not 1700khz) & just keep your ears open as you move around your
>>> neighbour & ...
>>
>> What is the significance of 612 Khz? Why that frequency?
>
>The most common downstream ADSL frequency band is 138 kHz to 1104 kHz.
>612 kHz is pretty close to the center of it, so if you had to pick
>one frequency to listen to that wouldn't be a bad choice.

Except of course the OP is on ADSL2+ so his bins go all the way up to
2MHz (and beyond) and the interference isn't at 612kHz - its a classic
double sideband centred around 1700kHz.......

The problem for the OP is that 1700kHz is in a radio ham band so
nobody is likely to do anything at all about it. If the noise was in
fact within the broadcast radio bands there would at least be someone
he could complain to.
--
John Naismith