Thanks. I've noted all your suggestions. Ideally the hub would be in the living room along with the TV and the main BT socket.
The problem is that connecting the TV to the hub, even in the same room has to be done by mini connectors or have extensive wiring going round room and 2 door frames to stretch between only possible location of tv and BT master socket.
I don't know if the hub can power 2 sets of mini connectors, but even this would mean a heavy load on my electrical sockets. This is something to be advised on by the visit.
I don't know the mini-connectors but you should just be able to add a third that will link to the others. The electrical load will be negligible. But if you mean occupying sockets then there are "passthrough" version with a mains socket built in, so you don't lose the use of the socket.
If the Box is the latest Pro that also has WiFi connectivity.
Thanks. Been considering your suggestions and the idea of using another filter sounds possible.
As I understand it, I can leave the Hub and computer in the bedroom plugged into the extension BT socket through the existing filter with the mini connector linking it to the TV in living room as at present. I can then switch the main phone back to the living room and plug it into the main BT socket through another adsl filter, moving the extension phone handset into the bedroom.
Googled it just now and also read that BT and several other providers require a filter to be fitted to every phone socket in house, so sounds like my interference problem.
Will go out tomorrow and buy a filter and see how this works.
Thanks very much. Problem seems to have been solved. Your suggestion about the second filter was correct. Bought second filter and moved the master cordless phone with answering machine through to the living room, connected to the main BT phone socket through an ADSL filter.
Quiet line test showed crackling noise when used without filter, but no sound at all when passing through the filter.
We don't have much selection of shops here, but found the filter on line at Argos and Currys. Half price at Argos so went to retail park to get one. Passed the EE/BT phone shop in town centre and thought I'd try there first as they were advertising mobile phone and broadband. Explained I was looking for ADSL filter but assistant said he'd never heard of such a thing. Asked what I wanted it for so explained needed to attach to BT landline socket to filter through broadband and phone. When he said I must have misunderstood and I explained that I had one already and needed a second one, the coversation finished. Not very impressed with service there!!!
I'm not sure how I change my entry showing solution accepted here.