Help! does anyone understand cordless phone signals?

[Reprint]

I have the weirdest issue with cordless landline phone reception. It is stumping the techie people I know in RL so am hoping someone here may be an expert ......

I have a single landline phone point in the house.
The first phone I plugged in allowed me to roam a long way - but only for the first couple of weeks. Reception then became increasingly poor (I sound burbly to callers, and phone actually cut out altogether if I went too far) This phone then died a death (no relation to signal issue .... I dropped it into a cup of tea! don't ask )

Next phone. Brand new. Excellent roaming reception which started to decay after 10 days. Returned to shop and exchanged as faulty.
Third phone - exactly the same problem. Took 12 days before I was restricted to indoors only.
4th (and current) phone. I paid a lot more for. Gave superb range for a week, and I am now back to exactly the same problem .....the signal breaks up within a very short range.

Troubleshooting has given the following clues:

• it is not a phone issue (now on mk 4/all work fine at the start)
• it is not a line issue (works fine for some days)
• it cannot be an interference issue (unless there is an almighty co-incidence that the interference only occurs when it knows I have had a new phone for a week)
• brand new phones do have some reduction of signal on the left of the garden (much more than on the right)
• I have an alarm system (but it is switched off so not sure how it could affect anything)
• it seems to settle at the external house walls as a boundary line, but with continuing use I even start to sound burbly even within the house.

So, does anyone have any ideas? what could cause reception to deteriorate in this way? every blessed time!

All input welcome ..... I work from home and need to sound clear and professional with clients. Can't afford to keep buying a new phone every week, and have zero option to use mobile instead as that only really has signal if I lean out of the bathroom window!!!

Have you got your base unit next to any large metal objects ? For example fridge? They should be a metre away if you can and also the same from a TV or microwave.
Also if you have Broadband do you have a micro filter in your socket ? You don't need one with fibre BB I don't think.
DH works from home and got a cordless headset instead which links to a plugged in phone.

No large metal objects (closest metal is a radiator about 10 feet away)
Micro filter on socket - and changed recently as part of troubleshooting v3 phone
Sky not connected to line (also part of troubleshooting v3 phone)

Thanks for responding though - I rather thought it might sit ignored !!

Good signal requires good power - could there be any link there?

It's not right next to your router is it ? If the router and base work on the same frequency it can cause interference.
Is the issue occurring when you are next to the base too ?
Also can be affected by wall thickness but as you say it starts off ok and then fades.
Hmmm I'm not back at work (telecoms)for the next few days but let me see what I can find out for you then . (Unless a MNetter wiser than me can solve!)

Wo - helpful people. Thank you.

It is relatively close to the router - but had discounted this as the issue because the signal is fine for a week or two. Surely if it was a proximity problem, it would happen from the getgo?
Also - thinking back - I separated them out on troubleshoot for v2 phone. It made no difference.

Miconium - I don't have a way to test current strength, but all appliances work fine, no dim lights etc. and I am on mains electric not generator.

Thinks .....
Sky dish is installed (externally) on the same wall as the phone line ....about 25 feet above the phone.
Could this affect it?

Again though .... I come back to the issue that, if it is that, it would affect it immediately - not give the slow decay of range.

I have known cordless phones interrupt the satellite signal on certain channel frequencies . Something to do with connection insulation. Suppose it may be possible - my dish is on same wall as phone entry point / base station as well without any issues.