Need to replace the cable from ADSL splitter to broadband port on SH2. What cable fitting required?

[licquorice · Accepted solution]

RJ11 - RJ11

[SuffolkSufferer]

Thank you very much

[Colin_London]

Do you still have an analogue phone line or have you been migrated to digital voice?

If you only have digital voice you can sometimes improve your broadband performance by eliminating the filter altogether and using a BT phone plug to RJ45 cable (cannot post links to examples unfortunately as it is against the rules).

[rbz5416]

Make sure the replacement RJ11 cable is wired "straight" & not "crossover".

[chrisjp]

BT's installation diagram for digital voice with VDSL copper is a bit misleading as it shows the filter as a must-have between the wall socket and the cable connecting to the RJ11 socket on the SH2. In fact it serves no function other than to convert the RJ11 plug to the BT plug to fit into the wall socket. As Colin London & rbz5416 say, the cable & filter can be replaced with a suitable RJ11 to BT plug straight cable.

[SuffolkSufferer]

Thanks for messages everyone. I had wondered if splitter was still needed.

[Colin_London]

I got an improvement of a meg or so from removal of the filter insertion loss. Always best to remove as much unnecessary circuitry as possible.

[licquorice]

There should be no insertion loss from a filter, the broadband path is directly connected, it is the phone path that is filtered.

[Colin_London]

Connectors themselves can have a loss, and there can be parasitic effects of the parallel filter. Getting rid of the filter gave me a small improvement bump (IIRC 0.8dB improvement in noise margin).