Shallow tale

[JohnP]

about internet failing when a TV is turned on.

Any explanations?

[Dave Liquorice]

This the welsh village that has suffered poor internet speeds for 18 months?

xDSL uses carriers every 8.625 kHz from about 8 kHz up to 2.2 MHz, each one signalling up to 16 bits. It doesn't take much interference to knock out a carrier or three. MW/LW broadcast stations can do it easyly, at night foriegn stations come to play as well. A Broadband noise source can affect all the carriers severly limiting the number of bits that can be signalled.

SMPSU's are noitorious sources of such RF noise (anything from wall warts to internal PSU's to LED/CFL lightbulbs) and all the digital electonics around these days doesn't help. Then you have deliberate radiation of broadband RF generated by ethernet power line devices.

[The Natural Philosopher]

Its all explained in The Register

Probably an arcing switch. When my boiler fires up the arc igniter plays hell with wifi and power over mains..

[Dave Liquorice]

Not overly convinced that a single shortish noise event would cause the the DLM to knock the speed back and for it to recover overnight to be knocked back the next day. In my experience the DLM needs quite a prolonged period of noise/disconnections, as in minutes, to kick in and takes up three days to recover.

A continious broadband noise source would just push the number of bits each carrier can signal down, thus reducing the total available throughput. This would manifest itself as speed changes that followed the level of interference quite quickly. ie Telly on slow, telly off fast.

That ought to looked at, the old or new (oil) boiler had no affecct on the WifI at all. Didn't even make any noise on a MW radio tuned between stations. I wonder why 612 kHz is mentioned by the Openreach bods?

[The Natural Philosopher]

The story didn't say that.It said that people lost broadband for a short period every morning

It wasn?t a 'continuous broadband noise source', it was specifically a single very powerful burst that splattered the spectrum and knocked everyone off line for a moment

This would manifest itself as speed changes that followed

Except it wasn't that.

Perhaps yours is gas, not oil. And has a pilot light

>

[charles]

That depends on which paper you read. In the Times "As long as the tv set was on, it was generatingb interference." The article also says that the interference got into the owner's router and was then fed out onto tehnphone network.

[Dave Liquorice]

cause

overnight

That's not how I read the first version I saw on the BBC News site a couple of days ago or the ISPreview version. Got bored reading the same verbatim (ish) and randomly embroidered press release after that... B-)

But unless that noise burst upset the DLM and it knocked the speed back people wouldn't notice the short outage and/or complain about "slow broadband", particulary at 0700 in the morning. My ADSL2+ connection drops occasionally, A&A send me a text when it does. The text is normally the first thing I know about it, even if I'm using the net at the time. The connection resyncs at the same speed as it was (+/= 100 kBps ish) within 60 seconds.

affecct

Er, then why did I write "the old or new (oil) boiler"?

Thought pilot lights had been banned ages ago but not having access to gas for 20 odd years I'm a little behind the times for gas boilers.

[JohnP]

Would it have to have been a CRT TV?

[charles]

That is definitely NOT what the Times reported

my boiler has a pilot light. It was installed in 1989, but I don't think there has been any retrospective banning - just not used on new boilers.

[alan_m]

And would anyone have noticed a short outage at 7am?

[The Natural Philosopher]

Not according to El Reg, who specifically IDed it as a short duration spike ofnoise

Well that might be in some sense true, but it sounds more like ignorant bollocks.

Newspapers do not employ STEM graduates these days.

And the times produces as much fake science news as the rest, apart from the guardian which is ALL fake science news...

[The Natural Philosopher]

If you get a long enough noise burst the connection will in fact drop and you will get a new attempt to train - possibly at a higher noise margin, this is very noticeable

My ADSL2+

That is just a glitch. My ADSL never dropped at all, although it would dynamically adjust its bit buckets and connection speed, unless there was a burst of noise on te line, when I would contact the ISP and get that sorted.

No idea

Well me too.

[The Natural Philosopher]

Almost certainly

[The Natural Philosopher]

Someone obviously did. OTOH it MIGHT have been something in the TV oscillating at MF and spewing crap out if the aerial.

Linescan is what - 16Khz? - with harmonics going well up.

[Andrew]

Cheapo plug-in mechanical timers for switching on/off lamps clobber stb's for a coule of seconds, depending on proximity.

Jeremy Vine had the 'expert' from Openreach who tracked it down on his program today Just after 1PM. Fault was caused by 2nd hand TV/DVD combo being turned on at the same time every morning, though broadband download speeds were said to be barely 1 meg anyway in the area.

[Andrew]

Openreach bloke said it was a TV/DVD combo, which must rule out a CRT TV. Did these ever have DVD players ?.

[Andy Burns]

Don't suppose he mentioned whether it gave continuous interference all the time it was left on, or just a spike at the time it was turned on?

[Andy Burns]

[JohnP]

Andy Burns [e-mail] wrote in news:ht1nuaF6t2cU1 @mid.individual.net:

Always amazes me if a luxury house or hotel is being described inevitably a "Flat Screen TV" gets a mention. As though it is something to yearn for.

[charles]

yes they did.