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Converting 3-wire phonelines to 2-wire

Disclaimer: This kind of work requires some level of DIY competency and the ability to use a ladder and comfort with being on a roof and in possibly confined spaces under the house and in rafters. An immunity to cobwebs (ahhh! spiders!) is useful. Also be aware that when working in rafters and under houses, you may be exposed to Asbestos. So be aware of asbestos and how to treat it – stay away from it unless you know what you’re doing. At worst this work will give you some pink bats itchiness, and maybe a headache. Either way, if you are at all missing confidence about doing any part of this – don’t bother! The returns are probably not worth it. Call 123 and pay for a professional to do it. You have been warned, all care – no responsibility!

Preamble: A mate of mine, Tijs, and his partner recently purchased their first house. And it’s a great place, all except for the DSL. For some reason they cannot sync up with the local exchange at any faster than about 768kbps. Which is not ideal, considering that they’re paying for 3.5Mbps.

So a bit of troubleshooting later and it turns out he has some archaic wiring in his house, namely 3-wire. Existence of 3-wire generally indicates that the wiring was probably installed between 1983 and 1996, so is between 10 and 23 years old. The Telepermits on 3-wire equipment expired over 1999 and 2000, and the standard since 1996 has been the simpler and more reliable 2-wire system.

What you need to know:
* You can perform maintenance on any phone wiring in your house. You own it.
* Telecom will look after the cabling between the exchange and your house. That’s what you pay a wiring maintenance fee for. Don’t tell me you’re one of those idiots who insisted on saving the $2.53 a month?! It’s not a meaningless fee you smeghat! Refuse to pay that fee and you void your right to whinge.
* The point where the two responsibilities change hands is called the demarcation point. This will usually be in a small box on the side of your house called an External Termination Point, or ETP. (see fig. something or rather)
* You have to keep to Telecom’s Standards, otherwise they might disconnect you and charge you to have it professionally fixed
* You will need these or similar

3-wire tended to have a Test Termination Unit (TTU) and a Ringing Capacitor on the PCB of the master jack, so this is a dead giveaway of which is your master jack:

Compared to a Secondary jack:

The existence of 3 wires being connected to your jack’s PCB too is a glaring indicator that you’ve got the 3-wire heebiejeebies. The cabling will also generally have 6 wires, this is known as 3-pair. The modern standard will have two wires connected to the PCB, blue and blue/white, and will only have 4 wires, which is known as the now obvious 2-pair.

This is a picture of Tijs’ cat, Calvin. Moving on…

Before ADSL, “good enough for voice” was good enough. So installer technicians tended to use whatever was available – nasty runs of bell cable and higher guage figure-8 are still dotting a lot of installs, and coupled with the caps and TTU’s, can cause a bit of havoc for the less-robust of DSL equipment. The latest Telecom spec states that cable runs of non-standard wire should be replaced all the way back to the ETP.

So we have to investigate what we have. Inside Tijs’ ETP we have some heavy duty Figure-8, which then enters the house and runs through the rafters to the floor of his attic, where it connects with a run of bell cable. This then goes down inside his pantry to underneath the floor, where it connects up with the 3-pair cable that is running throughout his house.


So we’ve basically got one of the worst case scenarios. If you do have 3-pair or similar right back to your ETP though, you can simply swap in some new 2-pair jacks and disuse the blue cable (connecting red and white to pins 2 and 5 respectively), if you dont have 3-pair or similar between your master jack and your ETP, then you’re going to have to make like us and replace it.

So to the Warehouse we went. You can get Telepermitted phone jacks just about anywhere, just not on Queen’s Birthday. The Warehouse was open though, and they sell Telepermitted jacks, so that’s where we went. We got one extension kit that has a jack, 10m of 2-pair cable and a cheap crimping tool, and we got two extra jacks. You will need enough jacks to replace all the ones in your house that you need to replace.

So with the 10m of cable, we planned to replace the run of cable from the ETP (figure 8 – bell cable) all the way to the 3 pair. This would reduce the amount of connections, cable segments and bring the house up to the current standard. We could also switch to using the modern blue/white pair instead of red/white, which would make it easier for any future work to be done by other techs. One of the things you learn when cabling is to futureproof and document for other techs – ETP’s are normally packed with excess cable for the purpose of future work. Tijs’ ETP was an unfortunate exception.

So we got under the house by making an access manhole:

Then got some excess 3-pair and pulled it as taut as possible, cut the bell cable connection clear off and pulled the bell cable up into the pantry. The 3-pair followed closely into the pantry and was pulled tight and stapled to the inner wall of the pantry.


By the way – if you need to do a cable run from rafters to piles, use cupboards/wardrobes or unused chimneys. It’s amazing how easily you can stealth your wiring. You should always staple/cablemount your wiring though, this is to keep the cable away from moisture and rodents.

Then up in the rafters we cut the link between the bell and the figure 8. The figure 8 was then pulled out at the ETP and the 2-pair pushed through to replace it. The 2-pair was then run along the rafters and down into the pantry, where it was linked up with the 3-pair using the following schema:

2 Pair ———- > 3 pair
Blue ———— > Blue
Blue/White —–> White
Orange ———> Orange
Orange/White -> Black

By the way – if you are needing to pass a new cable through a bulkhead which is in an awkward position; Don’t pull the old cable through. Strip about 5cm of sheath off the old cable and the same with the new cable, then tightly loop the two around one another. Then pull the old cable through, the new cable follows it through the bulkhead – easy!

Now, before getting up into the ETP and reconnecting everything – go through the house and replace all the jacks first. As I said before, if you have good cabling already, dont bother with the ETP and just use the Red and White pair on pins 2 and 5. If, like us, you’re modernising everything as much as possible, use Blue and White on pins 2 and 5. Once all your jacks are ready to go, then you can rewire the contents of the ETP.

Now we go up onto the roof, because for us it was the easiest way to work inside the ETP. Usually you’ll be at the top of a ladder though.

There’s always time for posing like an idiot:

And enjoying the view:

But as you can tell, we were running out of daylight, so back to work. Here I am perched safely on the roof, working in the ETP:

And from the ground, to prove that gravity is not a problem:

The ETP inside when all rewired, showing blue to blue, and blue/white to blue/white, with the orange-orange/white pair tucked back. You can also see in the bottom corner that I have marine siliconed where the 2-pair enters the house.

By the way – If you can locate a good DSL splitter, you can install it in the ETP while you’re at it. DSL frequencies are split and sent across the Orange pair. Ensure you have a full circuit from the ETP, and terminate the orange pair at another jack. This jack will become a dedicated DSL jack. You could alternatively use a dual jack to perform this purpose instead of two jacks side-by-side. In our case, we just had to connect orange to orange and black to black behind each jack from the master jack onwards, at the last jack in the line – the orange and black pair can be used for a dedicated DSL jack if Tijs so chooses.

So what advantage does this all have? It can potentially decrease noise on your line, and provide better connectivity for sensitive DSL equipment. Or it could do nothing. Either way, you’re up to the latest spec so you’re potentially eliminating your house wiring as the cause of any issues. Then it’s all in Telecom’s ballpark.

Did this fix Tijs’ problems?  Nope.  Using a super secret diagnostics number we got some technical specs about his line, and judging by the capacitance reading on the line – he’s probably in the 5.5km to 6km range from his exchange.  The rest of the line specs check out quite favourably, so his line could be tweaked a bit further if he paid for it.