Rotary Phone Wiring

redstarblanch

I set up an old rotary NT telephone and it works perfectly except it doesn't ring. I read that alot of new eircom wall sockets don't have the ring wire terminated but I can't find any info on how this should be done.

There is white/orange to L1 and orange/white to L2 (screw in terminals).
There is white/blue to L1 and blue/white to L2 (block terminals).
The green/white and white/green wires are disconnected.

I think the orange wires come from outside and the blue wires are from a phone socket upstairs.

Any help is greatly appreciated.

swampgas

redstarblanch wrote: »

I set up an old rotary NT telephone and it works perfectly except it doesn't ring. I read that alot of new eircom wall sockets don't have the ring wire terminated but I can't find any info on how this should be done.

There is white/orange to L1 and orange/white to L2 (screw in terminals).
There is white/blue to L1 and blue/white to L2 (block terminals).
The green/white and white/green wires are disconnected.

I think the orange wires come from outside and the blue wires are from a phone socket upstairs.

Any help is greatly appreciated.

I'm pretty sure you can't fix this by moving wires around - you will need an adapter (BT -> Eircom) which will allow the ring signal to be fed to the third wire of the old phone. I'm assuming that the phone has a standard RJ11 two-wire plug in it, you may need to replace it with a BT plug /cable so the adapter can be used.

redstarblanch

While searching for information I came across the following image and a quote from the thread relating to it states "You can ignore the "R" terminals, they're only used when wiring up old fashioned rotary dial telephones with bells".
This is why I'm looking for wiring info.

[IMG]file:///Users/tonymccrossan/Desktop/jack-diagram.gif[/IMG]

swampgas

redstarblanch wrote: »

While searching for information I came across the following image and a quote from the thread relating to it states "You can ignore the "R" terminals, they're only used when wiring up old fashioned rotary dial telephones with bells".
This is why I'm looking for wiring info.

[IMG]file:///Users/tonymccrossan/Desktop/jack-diagram.gif[/IMG]

A phone line has about 50V DC on it, the ring signal is about 90V AC superimposed on top.

In a BT system (I'm assuming this is an old BT phone), where the two wires from the exchange enter the house, there is a box with some components in it (a capacitor and resistor) to extract the ring signal and put it on a separate wire. This was done to avoid an issue where the bell on other phones in the house would "tinkle" whenever a phone was dialling a number. The end result is that the BT phone gets the ring voltage on a separate wire.

An Irish phone socket does not split the ring signal to a separate wire, which is why you need to have the adapter.

http://www.marcspages.co.uk/tech/6104.htm

http://uk.answers.yahoo.com/question/index?qid=20110104075453AASlFxR
http://www.rob-r.co.uk/other/UKphonecatwiring.htm

redstarblanch

Thanks for your input. The old rotary phone is an old P&T/Eircom phone that was used in my Grand Parents house in Dublin. It has a standard phone jack just like a modern phone!

swampgas

redstarblanch wrote: »

Thanks for your input. The old rotary phone is an old P&T/Eircom phone that was used in my Grand Parents house in Dublin. It has a standard phone jack just like a modern phone!

I have to admit I don't know much about older Irish P&T wiring - whether they used the BT method in the past or not?

Can you open the phone up and see what the internal wiring is like? Is there a terminal in it for a bell wire? Is there definitely a bell in it ?

redstarblanch

I've attached a (bad) photo of the bell. There are two bells linked to a red and black wire via what looks like a motor!
Hopefully you can make this out from the photo.

swampgas

Looks like a circuit board in there with enough components to mean that the bell is handled internally - i.e. no BT adapter required, maybe.

I think it's out of my league at this stage though :-(

Solair

The reason those old phones had 3 wires was to allow an anti-tinkle circuit to be used.

If it wasn't used, the phone could potentially 'tinkle' when you dialled on any other phone connected to the same line. The dial pulses caused the bell to ring!

P&T wired them like this:

If you only had one phone, they'd just connect two of the wires to one terminal of your phone line and the remaining wire to the other.

They had some kind of a box with a capacitor in it if you'd more than one phone and used 3rd wire ringing, but it depended on the model of the phones used, as some were immune to bell tinkle and didn't need it.

I don't know what the colour code was.

Telecom Eireann / Eircom branded phone sockets contain circuitry that allows an old phone like this to be hardwired to them.

You need to connect the phone's wires to terminals marked L1, L2 and R (Ringer). However, not all of the phone sockets have those circuits enabled. The R terminal is usually left unconnected for normal phone wiring here.

If the phone doesn't ring, or tinkles a lot, you can use a BT master socket - just connect it to the extension wiring side and the line to the line side.

The Brits still use that now obsolete 3-wire anti-tinkle system for some reason!

Telecom Eireann / Eircom / P&T ditched it in the 1970s when they introduced the current RJ11 modular sockets when they introduced digital exchanges and all that current generation stuff.

Third wire ringing was used in quite a few countries e.g. France, but it was mostly dumped by everyone except the UK who seemed to cling onto it out of tradition or something and actually implemented it in their modular phone plug/socket system introduced in the 80s!

So, basically, if you use a British socket you can connect up an ancient phone!

I would suggest that you figure out the colour codes by trial and error.

Just try all possible combinations of the 3 wires on the L1, L2 and R terminals.
Ring your phone and test it. When it works, you've got it!

Capt'n Midnight

Try the phone on it's own , disconnect all other stuff on the line. if it works then it's because of the REN ring equilivant number - the line only supplies so much power for ringing


anyone know a way to convert from pulse to tone ?

Solair

It shouldn't be any issue with REN on an eircom line, there's plenty of power to ring bells.

The issue is that the phone needs a capacitor in the socket to shunt the ringing voltage onto a 3rd wire.

You need to connect it to a BT master socket.

Any of these will do : http://www.screwfix.com/search.do;jsessionid=yNBRT1DGtNbL13WjJjYnyflGZxn1wm5nbdvTNTg1fWJbXFmLPDt5!-1166497430?fh_search=master+socket



Irish phones no longer use this setup, all phones are just connected to the A / B incoming wires i.e. they're standard 2-wire phones the same as the US/Canada and most of Europe.

BTW: Eircom sockets do have this circuitry on board, but it seems it's not connected in most of them. The idea was that if a modular socket system was being added in the early 1980s, the end user could retain their old rotary dial-telephones on other extensions.

In reality, Telecom Eireann didn't leave old rotary-dial phones in place if they upgraded wiring in a house. They'd just rip out all the old 1960s/70s stuff and replace it with modular sockets and push-button / tone dial phones. Everything was just wired the most straight forward way i.e. with 2 wires.


For DSL, this is actually a big advantage as the ringer circuit on British internal telephone wiring tends to degrade DSL signals and add interference. Many UK DSL users cut it as most modern phones don't need it anyway.

Also, where there was only one rotary dial phone installed, i.e. most houses, and no extensions, there was no need for ringer wiring. Two wires are connected to the "A" side of the line and one wire to the "B" side so the ringer is in the same circuit as the phone. If you connect extension to this setup without installing the ringer wire circuitry, every time you pick up a phone or pulse dial on a phone, the other phones' bells would 'tinkle'. So, if you dialed 5 on an extension phone, the other bells would tinkle 5 times and so on.

There were also all sorts of wiring methodologies used and different wiring plans depending on what type of phones were used. They weren't standard and were not intended to be user-installed. So, really, without knowing a lot about 1960s/70s wiring standards used by P&T, you'd kind of have to experiment and figure it out yourself.

Alternatively, try and find some old guy who worked for Telecom in the 1970s They can usually be identified by a smug luck and a huge pension (joke)

mbur

Our old pulse dialling 'coffee grinder' is wired the irish way with only two wires. There is a little mechanical lever at the bottom that silences the bells.

musically challenged

I wired my mothers old NT and Ericsson rotary phones by shunting/shorting the B line with the R ringer, no master socket or capacitor involved.
If you are confused with which wire is which try the various combinations as previously suggested.

Solair

musically challenged wrote: »

I wired my mothers old NT and Ericsson rotary phones by shunting/shorting the B line with the R ringer, no master socket or capacitor involved.
If you are confused with which wire is which try the various combinations as previously suggested.

That's not shorting them, that's how P&T wired them when there was only a single phone on the line.

Two wires connected to 1 lug and 1 to the other.

You won't really get much tinkling anyway as your other phones will be using tone dialling these days. Although you may get a little ring of the bell when you pick up the phone / put it down or press "R" to answer call waiting.

It was only an issue when all the phones on the wiring system were rotary dial.

Also, some of those phones don't have any tinkling issues and are happy enough to be wired in a two-wire system.

If you have an eircom branded socket, just take a feed off the L1, L2 and R.

On the newer sockets, there's a connection point at the back of the face plate.
On the older ones, there are punch-down connectors at the top of the socket.

In normal Telecom Eireann / Eircom wiring the R terminal is just totally ignored. But, it is there and can be used.

Worth a try though!