BT master socket + re-wiring + i-plate

[PeterC]

Thanks, I'll have look.

[Chris Bartram]

I stand corrected- I thought the overnight would miss the resistor in the NTE.

[Denis McMahon]

You can do all the work yourself, although you may wish to ask BT Openreach to re-site the master socket (they will replace it with an NTE5 if they do so).

The best strategy for ADSL is:

Firstly, fit an NTE-5 or get Openreach to fit one at a suitable location.

Then:

1) Fit a filtered faceplate[1] (which as others have said, is not the same as an I-Plate) on the NTE5. 2) Install the ADSL modem / router adjacent to the new NTE5. 3) Use a UTP[2] modem cable. 4) Replace all existing telephones with modern 2-wire dtmf signalling phones. 5) Wire extension sockets in parallel as one or two daisy chains from the filtered connections on the faceplate using connections 2 and 5 using either CW1308 standard telephone cable or cat-5 utp data cable.

If (2) is not possible, and you have purchased a faceplate with an unfiltered connection, you can use cat-5 utp data cable or CW1308 telephone cable to run a separate unfiltered connection. You may wish to purchase an RJ-11 faceplate connection for this socket which will accept the adsl modem lead. I used euro module faceplates and an rj-11 euro module from e-bay.

If (4) is not an option (it should be, you can get Binatone Trend 3 LCD for less than £10.00 each new!) then you can provide local bell signals in the sockets by using what used to be called a "PABX Master Socket". These can be made by removing the "out of service resistor" and "surge suppressor" from a pre NTE-5 style master socket, leaving just the connectors, socket and ringing capacitor on the circuit board. There's a good guide to different LJUs here

As you will be fitting several sockets, I suggest that you invest in a proper punchdown tool. Search for "krone tool" in ebay.

You may find the write-up I did here interesting.

Note that each terminal in a punch-down idc connector can only take 2 wires. You can buy a connection block that is designed to connect 4 x 6- way CW1308 using 2 parallel sets of 6 way idc connectors. This is often implemented as 4 x 3-way idc, with one pair providing capacity for pins

1,2,3 and the other linked pair providing capacity for pins 4,5,6. This can be used to feed 7 sockets from one pair as follows.

Given the usual arrangement of 4 sets of 3 terminals, two sets labelled as 1-2-3 and two sets as 4-5-6, designate one complete set as 1a-6a and the other set as 1b-6b.

Link 1a-2a, 2a-3a [2a now has 2 wires] Link 4a-5a, 5a-6a [5a now has 2 wires] Incoming pair to 1a, 6a [1a, 6a now each have 2 wires] Socket 1 to 3a, 4a [3a, 4a now each have 2 wires] Socket 2 to 1b, 6b Socket 3 to 1b, 6b [1b, 6b now each have 2 wires] Socket 4 to 2b, 5b Socket 5 to 2b, 5b [2b, 5b now each have 2 wires] Socket 6 to 3b, 4b Socket 7 to 3b, 4b [3b, 4b now each have 2 wires]

Rgds

Denis McMahon

[1] In my experience, active filters are not automatically better than (or even as good as) passive ones. [2] I tried a shielded twisted pair (stp) adsl modem lead and it actually gave a worse performance than a flat modem cable. The best modem lead I have found so far was a utp one.

[Bob Eager]

That is the right way round. But for most purposes it's immaterial - only some older US modems, and answering machines, care.

[George Weston]

Or even better, rip out all the internal wiring and buy a DECT phone system.

George

[The Natural Philosopher]

stanley knife works. also credit card or similar.

[Andy Wade]

470k on the end of (potentially) several miles of PVC cable? - unlikely I think. It would have to be an AC test, because of the series capacitor. Even at fairly low frequency the capacitive reactance of the line and the shunt dielectric loss (leakance) will surely both be much lower. In the old GPO days of hard-wired phones and low-impedance bells I believe they used to keep records of the on-hook impedance of each line, as seen at the exchange, for diagnostic purposes. That way they could detect when mods were made (illicit extension phones etc.), but I guess the coming of the LJU600 put paid to all that. For finding line faults I think they now use TDR techniques.

[Graham J]

[snip]

Also you could fit a filtered faceplate to the master socket, distribute the filtered phone signal as desired, and plug a standard Cat5 patch lead of suitable length into the ADSL socket on the filtered faceplate. Yes it will plug in, the socket is actually RJ45.

At the far end of the Cat5 patch lead you put the router. Terminate the cat5 patch lead in an RJ45 socket, or simply fit a back-to-back RJ45 adapter. Then put the short lead with the RJ11 plug from the router into the patch lead.

Result: the unfiltered signal from the faceplate filter is carried over the high quality twisted pair Cat5 cable directly to the router. This should give at least as good performance as siting the router beside the master socket.

-- Graham J

[Bob Eager]

Perhaps on some faceplates; not on mine, though (from Clarity).

[Graham J]

Yes, I thought that too, until I tried it!

But mine are from ADSLNation or BT.

[Dave Liquorice]

And when dialling.

Wonder how many people these days could make a phone call if the keypad had stopped working?

[Dave Liquorice]

And put up with the distortion. DECT isn't as appalling as mobiles but it's still noticably worse than the incoming line.

And make sure there is some other provision for making a call (999?) when the power is off.

[Denis McMahon]

The Pressac, Austin-Taylor and ADSLNation faceplates I have are all RJ45 sockets (albeit not with all contacts fitted).

Microfilters are RJ12.

Rgds

Denis McMahon

[dennis]

Not surprising, that's exactly how BT did my parents house.

[Peter Johnson]

If, having read all of these constructive replies, you are still uncertain about your ability to diy look in the yellow pages under telecommunications engineers for an ex-BT engineer to do it for about £30 plus parts.

[Andrew Gabriel]

and some callerid circuits, such as used in first batch of CD50's, and in some modems which handled BT callerid. They failed to detect the line reversal if the line polarity was wrong.

BT/GPO always required all their supplied equipment to work with the line connections reversed, and for the most part, this continues now with all phone equipment even though it's all been deregulated.

[Allan]

Thanks. That was a very good lead, which prompted several thoughts and more research based on all the info in the other postings on this thread. Thanks to all.

[J.G.Harston]

I could do 121, but I wouldn't be able to do 999. ;)

JGH

[Bob Eager]

But 112 would be far more useful!

(I wonder if that's why they use that number. I know why they originally chose 999, before anyone asks...)