This will NOT `help` you but I wanted to let you know that I have a very similar problem. Since the first connecting of a Router to my telephone line - Ihave had the same noise/interferance problerm.
I also have tried `every` combination of microfilters and changing microfilter brands etc. - nothing that I have tried worked - the ONLY thing that stops the noise/interferance is to turn off the Router - which I do to make/take telephone calls.
I narrowed the problem down to the Router fairly quickly and obtained a replacement - that ALSO had the same problem! - I borrowed a Router of a different manufacturer - [somehow configured by a friend to `work on my ISP]- that also had the same noise/interference so I thought that I had `eliminated everything EXCEPT `faulty` internal wiring.
I called in a telephone engineer [B.T.] who checked out my Incoming AND Internal wiring - NO FAULT was found - nor could he diagnose what was happening regarding the noise/interferance!! - so I am `stuck` with having to turn off the Router when making/taking telephone calls.
Sorry that this is no help - BUT I wanted to let you know that - in my case - the `problem` could NOT be resolved!.
As an Engineer [Heating] - I am not used to `unsolvable` problems - I know how frustrating this is for you - "Good Luck" - CHRISMUR.

Edited by deleted (Mon 22-Mar-10 21:21:37)

What you describe is almost certainly a high resistance fault. If you report the problem through your ISP you should get an ADSL trained engineer - some of these guys actually have opposable thumbs and may even find the fault and fix it.

I agree entirely, and I think this could be the OP's problem too.

Except he says it is the same with the router turned off. I suppose it is vaguely possible that the DSLAM is faulty and continues to transmit even in the absence of a signal from the client but even then it doesn't expain why the noise can only be heard with a filter plugged in unless the loading of the phone stops the transmission???

My own theory remains that the problem is caused by the switch mode psu for the dect phone despite the distance - it is maybe radiated by the mains wiring. That would require two dodgy ones of course according to what the o/p said....

Edited by kwikbreaks (Tue 23-Mar-10 09:20:30)

In reply to a post by kwikbreaks:

Except he says it is the same with the router turned off.

Yes, but he also later said that he wasn't totally sure that this was the case, and was going to take another look.

In reply to a post by kwikbreaks:

My own theory remains that the problem is caused by the switch mode psu for the dect phone despite the distance - it is maybe radiated by the mains wiring. That would require two dodgy ones of course according to what the o/p said....

Yep, I was under the impression that he'd tried at least two different types of DECT phone. One thing that occurred to me - would noise pickup from adjacent pairs in the cable be enough to cause a problem if there was an HR joint somewhere ?

In reply to a post by zebedeee:

One thing that occurred to me - would noise pickup from adjacent pairs in the cable be enough to cause a problem if there was an HR joint somewhere ?

So crosstalk causes an HR fault in the line to show up but only with a filter in circuit?

Maybe but I reckon the odds are comparable with those for it being a joke perpetrated by an alien in a UFO parked on the lawn and hidden by a SEP field.

I'm not even convinced I could solve this one on site so I reckon I'm going to stop taking guesses based on the certainly incomplete and possibly incorrect information posted here.

Still cannot find my card reader for showing you guys the connections. But I have checked them and they appear "clean" and simple (no crossed wires etc).

I haven't been able to get out and get a voltmeter to test the incoming cable just yet to see if that's reversed, but most of you guys don't seem to think that will make a great difference.

What I have been able to do is shoot some quick video on my iPhone with and without the filter attached taken at the master socket, so show you guys (mostly so you can hear) what the situation is like.

I used two DECT phones, the first is a magicbox phone: http://www.johnlewis.com/230649923/Product.aspx and the second is a Panasonic: http://www.johnlewis.com/230588206/Product.aspx The Panasonic is MUCH worse than the Magicbox, but you can (hopefully) hear a difference on both with and without the filter.

Might have to turn up your volume a fair amount.

Distance from plug, base unit, to master wall socket: http://www.youtube.com/watch?v=BhPCUlTgpSc

First phone (magicbox) with no filter involved: http://www.youtube.com/watch?v=KDVZH5tl5Ds

Quite a big difference, but you can still hear the dial tone.

First phone (magicbox) with filter involved: http://www.youtube.com/watch?v=rnl3I1cE36w

Second phone (Panasonic) with no filter involved: http://www.youtube.com/watch?v=0zvmZbZc4v4

HUGE difference between these two, I struggled to get the iPhone to pick up the feint dial tone / white noise...

Second phone (Panasonic) with no filter involved: http://www.youtube.com/watch?v=EiuK_nKl_Y0

The bangs/pops are the phone earpiece hitting the iPhone microphone.

This is with ALL router, computers, wireless devices in the house switched off and unplugged.

Here's some photos of the socket (master) and extension.

I've done most testing with the extension disconnected, but it really doesn't seem to make any difference at all. Certainly nothing I can detect by ear alone!

Flickr images, master socket wired up only: http://www.flickr.com/photos/oxleywoodsphotos/446615...

Master with extension: http://www.flickr.com/photos/oxleywoodsphotos/446615...

Extension: http://www.flickr.com/photos/oxleywoodsphotos/446693...

Doubt these add much to the conundrum, but maybe there's a clue I can't see and someone else can?!

First observation, thats a cheap and nasty 'master' socket.

Reverse the polarity on the incoming pair, then reconnect the extension as it is, blue to two, and white/blue to 5.

You mentioned ages ago that theres a joint on the feed pair, is there any way you can move the master up to the joint and connect there, ruling out the current wire feeding the master ?

Do you think a new socket might be a wise investment? I'm not at all surprised it's cheap and nasty, the builders will cut every cost possible I'm sure.

I already removed the "bridge" outside the house so the drop wire is coming straight in. The wire reaches easily inside the house, no idea why they felt the need to add some connections and wire to the equation!

I'll have a go at reversing the polarity and see if that makes any difference too.