We bought a twin set of BT Freestyle 750's a couple of weeks ago, and ever since we've had an irritating crackling sound on the line when we use them. Sometimes it's worse than others. These weren't brand new, but were 'Refurbished Grade A', so I didn't expect to have any problems with them.

I've tried a few different things to diagnose the problem, all to no avail. These include:-

-Checking all connections are secure
-Switching electrical appliances around the base off
-Taking the micro filter the base is plugged into out

Still the crackling is there though It's on both handsets too. Is this a line problem? Is there anything else I can do to try and fix it? Any help much appreciated

Edit: Some additional info - our phone service is with Talk Talk, and the phones we had previously didn't have this problem.

Do you have a corded phone you can plug into the line?

If so swap that for the base station and see if you get any crackles on that. If the corded phone is crackle free then chances are it's not a line problem.

If you have the phones plugged into an extension socket try the corded phone at the master socket. If the master socket is one of the NTE5 types with a removable lower half to the front panel open it up to expose the test socket attached to the bit that stays on the wall.

The test socket connects directly to the incoming BT line and removing the front panel should isolate all your internal wiring (if it's wired properly). If you get crackling on that with a corded phone then it's a line fault.

If the corded phone is quiet but the cordless phones crackle in the same socket then the most likely cause is a fault with the cordless phones or interference getting into them. The only way to work out which is to try and find a similar phone you can try in the same location. If a known working cordless phone does not crackle on your line then chances are it's the phones you've got. If however it too crackles there may be something causing interference. Tracing what that is can be a right royal pain in the bottom however.