BT master socket 5C Mk4 extension wiring.

[#1]

I've wired in a 5C Mk4 master socket, with my router plugged into the Mk4 front plate and a telephone extension connected to the terminals on the 5C rear plate. Is this extension already filtered, or do I still need an ADSL splitter to connect my extension phone?

[#2]

This https://www.run-it-direct.co.uk/blog/installing-a-mk4nte5c-combined-socket-14.php should help

The connector on the 5c rear plate is filtered by the mk4 faceplate. It seems strange but the plug that connects the faceplate has connectors top and bottom. The incoming line is connected via the top pins and then the return filtered connection is fed back to the rear plate by the bottom pins.

Hope that helps

[#3]

These sockets also have terminals giving you unfiltered output too, useful if you need to plug your router into a remote ADSL socket.

[#4]

Thank you MisterW. What you say confirms what I thought. The problem with the 'run-it-direct' info, which I think I've seen before, is that it says 'extensions for telephones ...' which implies telephones only but does not actually say so.

Ed

[#5]

Hi Gel. Your reply appears to contradict the advice given by MisterW. If the terminals are filtered for telephones only, then I don't see how they can be used for ADSL. I am aware there are separate ADSL terminals on the Mk4 faceplate for a dedicated ADSL extension.

Ed

[#6]

The terminals on the 5c backplate ( 2nd picture in the link ) are filtered, so extensions wired to this can ONLY be used for telephones.

The terminals on the back of the mk4 faceplate ( 3rd picture ) are unfiltered. Extension wired to this can be used for broadband or telephones BUT will need a filter to be plugged in to the extension.

[#7 · Accepted solution]

Thank you again MisterW. That has clarified things. I didn't realise that the Mk4 faceplate terminals could also be used for telephone so Gel is also correct.