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[Bodge99]

Hello All,

I'm in the middle of upgrading to FTTC from ADSL2.. this is due to be completed today.

I've posted in the networking section on this forum regarding this (see http://forum.kitz.co.uk/index.php?topic=14304.0 ).

Anyway, as part of the ongoing house redecoration/revamp I've totally redone the front room. Part of the work involved lowering the ceiling (1911, old cracked & blowing plaster etc. Anyone who has an old house knows exactly what I mean.). I also installed new insulated plasterboard (foil backed insulation, both for heat and sound insulation.) on walls and ceiling.

New LED lighting was also fitted.. can you guess what is coming next?

Yes, turning on the LED lights caused so much RFI that the router disconnected from the line and would not reconnect until the lights were turned off.

Before I did this, the ADSL router was on a shelf in the back room.

The first thing I did was to move the router upstairs to where the telephone line enters the house.
This allowed the lights to be used without service disconnections. The lights did cause some speed reduction as could be clearly seen with the use of Dslstats. The bitloading graph clearly showed problems with drops in the higher frequency bins.

I've spent a great deal of time looking at this and have identified the majority of the problem is caused by EMI induced into the house telephone cabling. Disconnecting this reduces the problem markedly.

Now this problem occurs with both a Billion 7700 and a 7800N. I was prepared to tolerate this as I'm in the process of revamping everything (network and telephone cabling) and have devised a layout that totally cures this.

Now the interesting bit:

As part of the upgrade to VDSL, I purchased a couple of HG612s from Ebay. I've unlocked them and am currently using one in ADSL2 mode.

SWMBO got me to put up a wall cabinet in the front room yesterday evening. I had to turn the LED lights on so that I could see clearly what I was doing. I did a quick check of the line stats to see how the current RFI problem was affecting the HG612.

I was very surprised to see no line stat degradation whatsoever. This indicates to me that the Billion routers **may** be more susceptible to RFI/EMI problems?

Has anyone else seen this?

Comments appreciated.

Bodge99.

[JGO]

I also installed new insulated plasterboard (foil backed insulation, both for heat and sound insulation.) on walls and ceiling.

Is this Ali foil ?  If so would have some effect on radiated/induced RFI at XDSL frequencies, so your front room could now be a screened box to some extent.

------------------

This indicates to me that the Billion routers **may** be more susceptible to RFI/EMI problems?

In the 1950s RF people realised that receiver sensitivity to weak signals has to be sacrificed to work in the presence of interference. A modem is a specialised receiver but the same principles don't always seem to be applied, so you could be right. 

[Bodge99]

Hello,

Not quite a perfect Faraday cage... but a pretty good approximation of one!

I'm able to get some wireless from the AP in the room above, but speeds are reduced somewhat.
The 3rd router in this room solves this and other problems.

Bodge99