We’ve got cordless phones at home and are getting more white-noise & crackling when the cable to the router is plugged in.
The master socket has an upgraded ADSL Nation XTE-2005 filtered faceplate, and the cable to the router (a Dlink 740R) is an upgraded screened RJ11 cable. The router cable runs along skirting board on its own, away from power cables.

It’s not always bad, but the phone wasn’t really usable last night for example, until I disconnected the router cable temporarily, but is pretty much ok today.
It does seem to be worse since BT did some work with laying new cables / fibres in the last year or so…

Has anyone else experienced this, and what helped improve it for you?

Interwebs searching has revealed that cordless phones are often prone to interference from Wi-Fi & vice-versa.
New, better, phone time then!

Might not be the router. We’ve got an intermittently crackly line at work, which gets interference at random. Sometimes it’s fine for days, sometimes it’s unusable. Wet weather seems to make it worse but not exclusively. The odd thing is it goes away completely all of a sudden, sometimes, when you plug and unplug the phone, or plug a different phone in – and then it comes back later, even with a new, known-good phone connected. Same thing happens when BT run a line test – it magically fixes itself. Bizarre.

Anyway, BT have spectacularly failed to do a sodding thing about it despite repeated calls and complaints, and it’s got to the point where I’m considering just cancelling the line and going back to using my mobile for all calls again.

Have you tried replacing the Microfilter?

It was like this before fitting the fancy master socket faceplate with integrated filter & screened cable, they made no difference so £20 wasted!
As Mr Mint says, it’s random so perhaps is affected by general atmospheric conditions. Or a neighbour with a microwave on, etc.

Apparently changing to DECT phones will help, but I don’t get why it gets better if I disconnect the cable to the router, as the Wi-Fi will still be on anyway.

Have you any extension sockets or is it just the single Master socket?

What state’s your internet connection in?

One master socket, one cordless basestation off that, another handset at the other end of the flat. Wi-Fi router directly from master socket and in the middle of the two handset locations.
The phones are DECT as well, don’t really get it why the problem happens?!
ADSL connection occasionally craps out, in the past this seemed to happen when we were getting this interference too.

Did it do it before you introduced this ‘shielded’ RJ11 cable?

Does it do it as soon as you connect the router, or after 30 seconds or so?

Yes it did do it before, which is why I upgraded the filtered faceplate & cable from cheap ones.
When it’s bad you can disconnect the RJ11 cable and it gets better (though still a bit crackly), but reconnect and it’s bad again.
I replaced the router and it didn’t really make any difference.
The majority of the time it’s ok, and we couldn’t identify a pattern to it happening. I suppose a nighbour above/below us could have something electrical switched on?
When it’s bad, the adsl connection/speed usually gets worse too.
I haven’t tried switching off the router itself yet to check that effect.

In honesty, I think I’d be tempted to get BT involved. It’s sounding like a line fault to me. If the only thing you’ve got connected is the phone and it’s still crackly, it’s either a bad phone or a bad line.

To confirm this you could jam the phone into the test socket (where the ADSLnation plate plugs into) without a microfilter or anything, just temporarily, to see if it still persists. That’ll rule out routers, home wiring, etc.

If you can, I’d beg / borrow / steal another phone for testing purposes first (you can pick up a corded handset for pennies these days, and it’s worth having in a cupboard in case you ever have a powercut for an extended period of time).

Is the wireless phone using ‘digital wireless’? If so, then forget interference from whatever. My guess is a crappy analogue phone degrading after use and abuse. Failing that, either a fault either on the line or in the wiring in your house.