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Old 21st Jul 2019, 2:55 pm   #14
Riccardo Grillo
Join Date: Jul 2019
Location: Colchester, Essex, UK.
Posts: 15
Default Re: Two DSL filters, two 706 phones, bell tinkle

Hi dagskarlsen,

Your link made very interesting reading, and if I had the time, it would be the sort of thing I might want to play with - but who am I kidding? Still, it is nice to have it on here for reference.

Interestingly, when I finally went into my loft to look for a spare electrical enclosure to put my filter in, I found an old linebox-type BT master socket Virgin Media had fitted to this house on the day they presumably took away the previous BT linebox and left the cut line under the carpet and that I (annoyed at having to pay Openreach to fit a new master socket when the old one was removed by Virgin Media) had taken off and removed the Virgin Media wiring back to the ugly grey box outside my front wall.

Given that the smaller capacitor on my DSL filter did result in the ring being a a tad hesitant on one of my phones (one of the bell coil securing screws is missing and this makes it hard to adjust the bell accurately), I decided to use this spare master socket.

So I still have the Openreach 5C master socket at the end of the Openreach line (new a year ago and already the contacts between the faceplate and the socket are not entirely reliable, and why it has those awful click-in plastic capped IDC terminals instead of the usual kind of IDC ones is beyond me: they are terrible).

Into the extension terminals 2 and 5 of the Openreach master socket I have wired my orange pair - an unfiltered pair to the router extension in the lounge. Also a spare offcut pair, soldered onto the unfiltered side of the DSL filter circuit board is wired to this same pair of terminals.

The filtered side of the DSL filter is fed to the A and B inputs of 'my' internal master socket. Then the blue pair is fed to 2 and 5 and the green pair is fed to 3 and 5 on the extension side of my internal master socket and these cores are fed to my telephone extension sockets.

So now, if I understand Oldcodger correctly (from various threads), I think he DID intend a system very close to what I have ended up with here. Leave the Openreach master socket where it is. Wire an extension in a convenient location _using two cores only_ but otherwise in the conventional way, plug in a DSL filter to your extension socket, plug in your router to the DSL filter and then plug your own internal master socket into the DSL filter. Any internal extension you may require can be connected to the output terminals of your internal master socket.

Using your own master socket to provide the ring capacitor instead of using the one inside the filter ensures you have the 1.8 microFarad capacitor to allow you to ring multiple phones better. So there _is_ sense in using a master socket after the DSL filter if you have multiple phones and phones require a traditional 3-wire installation.

Thank you all for your help. I feel I have learnt a lot doing this.
Riccardo Grillo is offline