For the master socket the power point for the DECT phone is about 10 feet away on another wall.

I'm glad I'm not the only one flummoxed by this!

It is very very strange. To rule out the DECT psu can you try it using the standard phone + filter but with the DECT phone powered up.

I really can't see how things like A & B reversal or incorrect wire type could possibly lead to the symptoms you have.

In reply to a post by kwikbreaks:

I really can't see how things like A & B reversal or incorrect wire type could possibly lead to the symptoms you have.

Ditto.

In reply to a post by kwikbreaks:

I really can't see how things like A & B reversal or incorrect wire type could possibly lead to the symptoms you have.

The use of a non-twisted cable could lead to higher radiation of RF from the wiring, and all DECT phones have audio amplifiers in them which can be affected by signals which are not far out of the audio range. These audio amplifiers have an automatic gain control to prevent feedback between the earpiece and the microphone, and it doesn't take much to push them over the edge, and you can get feedback, which is often heard as a rushing sound or an echo.

P.S. The use of stranded cable rather than solid core can cause bad connections when IDC connectors are used.

Edited by deleted (Thu 18-Mar-10 10:59:01)

In reply to a post by zebedeee:

The use of a non-twisted cable could lead to higher radiation of RF from the wiring, and all DECT phones have audio amplifiers in them which can be affected by signals which are not far out of the audio range. These audio amplifiers have an automatic gain control to prevent feedback between the earpiece and the microphone, and it doesn't take much to push them over the edge, and you can get feedback, which is often heard as a rushing sound or an echo.

P.S. The use of stranded cable rather than solid core can cause bad connections when IDC connectors are used.

yes yes I know all that (although you seem to put a lot more faith in 4 or 5 twists per meter than I do) but that still doesn't explain why the problem only occurs when there is a filter in circuit even when there is no ADSL signal present - you need an awfully long length of cable for 3kHz to radiate very much.

Well, you assumed in one of your posts that the fault occurred with no ADSL router connected, but I've seen no confirmation of that from the OP.

In reply to a post by zebedeee:

Well, you assumed in one of your posts that the fault occurred with no ADSL router connected, but I've seen no confirmation of that from the OP.

First post

In reply to a post by BernieSteak:

Now, this happens even if we disconnect and switch off the modem and all other wireless enabled products in the house.

I stand corrected, sorry !

Makes it more puzzling doesn't it?

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

Certainly the ferrite cored inductors in the filters could make passable antennas but what is the source of the RF noise and what is rectifying it? Maybe a bad joint because of using multicore wire as you suggested but I doubt that.

Edited by kwikbreaks (Fri 19-Mar-10 10:34:58)

"When the DECT phone is plugged into the wall socked, any wall socket (we have the master and one extension) the line is fine.

When we plug the phone into a microfilter, regardless of brand (I shelled out on a new XF-1e as apparently they do amazing things) we get a great deal of line noise, and the phone is extremely quiet. Unusably quiet voices, and unbearably loud "noise" (hiss)."

Sounds back to front to me if the line is ADSL enabled.........

Edited by deleted (Fri 19-Mar-10 11:03:34)