Background warbling noise when using DECT phone

[#1]

Recently we have been getting a background warbling noise when we use a DECT cordless phone. It used to happen every now and again but now we are getting it all the time. We don't hear the noise when we used a wired phone. In order to try and track down the issue I have tried the following:

- tested the phone at my sister's house and there is no noise there so the phone seems to be ok

- tried a different DECT phone and handset but got the noise with them as well.

- plugged the phone directly into the master socket and get the noise

- plugged into the master socket with the cover off (there by disconnecting the internal extensions) and I get the noise

- turned off the mains electric to all circuits but the circuit the phone was plugged into to ensure that nothing in the house was generating the noise and still had the noise (don't have a smart meter so the phone was the only thing powered up)

- DECT Handset to handset internal calls don't have the noise.

- I tried the online line checker but it said there was no fault with the line. 

Any one got any suggestions?

Thanks

Jonathan

[#2]

My initial thought was that it could be the interrupted dial tone that occurs when a voicemail (1571) message is waiting. Im not sure why that wouldnt be the same on a wired phone though?

Its probably worth trying 1571 to see if there are messages and are causing the strange dialtone

[#3]

Thanks for the suggestion. I have checked and I have no voice mail messages so that's not it

[#4]

Have you tried switching off all electrical equipment in the house, to see if the noise disappears, the back on one at a time?

[#5]

Yes, I have turned everything off in the house apart from the phone and the noise is still there.

[#6]

Did that include the router?

Are you close to any other houses/flats?

[#7]

yes the router was off as well. I live in a detached bungalow.  The nearest house would be 3 meters away (from outside wall to outside wall) Any other house would be 20+ meters away from an outside wall of my house

[#8]

Then alas I am running out of ideas! It does sound like it is some kind of electrical/radio interference, could you rule that out by trying it elsewhere?

Unless it is aliens trying to make contact!

[#9]

Hi @jmagee 

This is certainly a cracker of a mystery! Initial thoughts are that it's some kind of RF interference getting into the base.

If it's at all possible, I'd try obtaining, or borrowing, a long telephone extension lead/reel, to remove the cordless base as far as possible from the house while plugged into the master test socket. Try it on various sides of the house. If it's weaker or stronger in different directions it might give a clue as to the source.

Can you describe the 'warbling' in any more detail eg is it constant in frequency and timing? Is it comparable to any sounds we might be familiar with? Is it the same day or night?

@Mustrum The OP did say that it's OK at his sister's house.

[#10]

I will look into getting an extension lead and trying the phone away from the house. I have tried it in my home office which is behind the house which has an wired telephone extension to the house and the noise is there. I also have tried wrapping the telephone lead of the base station round a ferrite core which didn't make any difference.

In terms of the sound I have been able to record it by calling myself using skype. The short audio file can be found here:

https://jmagee.com/phone.wav

Thanks for all the suggestions so far

[#11]

@jmagee 

Thanks for new info and the sound file. I don't recognise the sound.  🤔

What happens if you try the phone without the base being plugged into a phone socket, first with, and then without the lead plugged into the base?

[#12]

Hello  @jmagee

Thanks a lot for reaching out and I'm sorry to hear that you've been having problems with a noisy phone service. I've just run some tests on the line though which have not picked anything up to be honest.

I'd suggest having a quick look through our Phone Troubleshooting Guide to see if there's anything that you might have missed, and if not, head over to faults.plus.net and get the matter raised with our Technical Support Team.

As our tests aren't picking anything up though, an engineer visit will likely be required.

Troubleshooting Guide - https://www.plus.net/help/phone/phone-line-troubleshooting/