BT Everyday cordless - noisy on FFTP?

[rootfourme]

Hi,

Wondering if anyone can provide a steer on this one please.  

Had FFTP installed, removing the external copper requirement and feeding entirely digital telephony system.    Do have internal extensions to different rooms and the BT Everyday twin cordless handsets (under a year old...possibly 1st or 2nd quarter  2021) are off an original extension.   They were clear lines previously.  Now moved to FFTP they are hissy noisy when answer them or listen to dial tone. Assumed the extension was causing issues.

Deskphone next to the Full Fibre and plugged in to the router directly is crystal clear.  When add the BT Everyday handset via a proper splitter (x1 to the deskphone, x1 to the handset master unit) the deskphone remains crystal clear and the Everyday stays noisy.    Then when plug the BT Everyday cordless base unit *directly* to the router (base unit straight to router's telephone port, absolutely nothing in between)......still noisy!   So certainly not extension cable or splitter.  Absolutely linked to the cordless unit.  All microfilters have been removed, but hissing noise present if put one back in-line.

OK so some interference then?  Moved to different points in the house off the extensions.  No change.  So was clear when phone line came over copper, but now on fibre there is hissing background noise whilst all other deskphones are crystal clear.  All microfilters have been removed as none are required for FFTP digital telephony.

What am I missing please?  Any hints or suggestions? Many thanks.  

[imjolly]

Did you activate the existing phone so let's following procedure here.

https://community.bt.com/t5/Home-phone-including-Digital/Correct-way-to-enable-all-BT-sockets-after-...

[rootfourme]

Hi,  Thanks for quick response.

Well I've not specifically purchased the "Telephone Modular Cable, BT631A Plug to BT631A Plug".    The copper line in to the property is dead, cold chopped by BT engineer during the FFTP install, but the extension *does* still connect to and  through the old BT master socket.     The extension starts by the router with a "extension socket / back box", routes up and to the master socket and then spurs to the 2 other locations in the house.      The reply in that linked thread by jonstatt (‎12-06-2021 19h10 - edited ‎12-06-2021 19h12) is one I'll look into.  

However, even if I did use the BT631A to BT631A plug on the extension.........should there not be a crystal clear line when the BT Everday cordless base station is plugged directly to the SH2 telephone port?  Exactly like the deskphone is crystal clear?  That's the part of that thread which doesn't quite tally.  

Will work through that thread again.  Thanks again.  

R4M

[rootfourme]

Just disconnected the extension wiring  i) to SH2 router and 2) out to bedroom which converged in the now defunct BT master socket 5c.  Hence, the internal extension wiring is directly connected to each other now bypassing any connection within the 5c master socket.   

BT Everday cordless  is still hissy whilst at dial tone, but seemed clear (ish) when rang mobile and talked to someone in location elsewhere within the house.  Will check a few further details out..  Thanks