In reply to a post by kwikbreaks:

Makes it more puzzling doesn't it?

I wonder if we really have the entire story or if something is accidentally omitted.

I think you're right. I still think there's a wiring fault somewhere. What I'd like to see done is to disconnect all the indoor wiring, attach a master socket to the incoming pair, and then connect the DECT base unit via the ADSL Nation filter. While he's doing that, he could check the polarity of the A & B wires (that only needs a £5 meter which you can get from Maplins or a host of DIY stores).

It does, doesn't it ? I wonder if this will turn out to be a line card fault at the exchange ?

You have tried new filters, another DECT phone, problem exists whether the router is connected or not. You have removed the ringwires.

All the wiring has been disturbed. Not very difficult for one wire in one IDC to have become a problem.

I would suggest that you go round the sockets remove all the wires except those in terminals 2 & 5. Before you put the socket back together reseat the wires in terminals 2 & 5. If there is anywhere that there are more than two wires in any IDC connector that also could be a problem area. From what I understand you have a master and one extension so there should not be more than 2 wires in any IDC.

Also check that the same colour wire is in terminal 2 in the master as is in terminal 2 of the extensions and the same for terminal 5.

Sorry for the lack of feedback lately. We've had a house full of sick little and big people.

Anyway... I've taken photos, and I have removed the extension lead too during my endless "I'll try this combination then..." fault finding mission.

Someone mentioned the polarity of the incoming cables. Does this make a difference? The advice I read elsewhere suggested that as long as the correct two were connected to the correct points it didn't matter if they were "reversed"?

If it might matter, can someone suggest the correct meter to buy from the local Maplin?

I've taken it right down to only having the master socket wired up and using the X1-Fe filter and still the difference is there. Telephone is fine without the filter, noisy with it.

I've got pictures but lost my damned card reader so can't do it.

Can you confirm that if you plug your phone directly into an unfiltered, ADSL enabled "master" socket that it works fine, but when you add an ADSL filter you get a "hissing" sound and low volume?

I'm doubting my own sanity so I wont say "yes" right off the bat. I'll check it again and report back ASAP.

In reply to a post by BernieSteak:

Someone mentioned the polarity of the incoming cables. Does this make a difference? The advice I read elsewhere suggested that as long as the correct two were connected to the correct points it didn't matter if they were "reversed"?

If it might matter, can someone suggest the correct meter to buy from the local Maplin?

The polarity can be important under certain circumstances. A suitable meter would be the N20AX at £6.99, or the UZ82D at £9.99. The first one is digital, and the second one is an analogue meter. The A wire is positive with respect to the B wire, so a digital meter should not display a minus sign when the red probe is on the A wire, and the black lead on the B wire. On the analogue meter, the needle should move when the red + wire is connected to the A wire. You should set the meters to the 100V DC range, and you should read about 50V DC across the wires when the phone is on the hook.

Edited by deleted (Sun 21-Mar-10 00:02:30)

A & B would be on which connectors when they're numbered only. I do not have the "A/B" style master socket.

I'm sure I have a voltmeter somewhere, if not I'll try and get to Maplins.

Thanks for all the advice.

The A wire usually goes to pin 5 and the B wire to 2. You may find this useful.

'The polarity can be important under certain circumstances.'

My point was that an A/B reversal, if on the extension wiring may give faint problems with cordless phones. The OP seems to have ruled this out now. I'd love to go have a look at this one.