ECN Forum
Posted By: Belgian Telephone - 11/03/02 08:38 PM
What do phone plugs look like in your country?
This is how they look like here
[Linked Image from catalog.geindustrial.com]

[Linked Image from catalog.geindustrial.com]

[Linked Image from catalog.geindustrial.com]

[Linked Image from catalog.geindustrial.com]

[Linked Image from catalog.geindustrial.com]

[Linked Image from catalog.geindustrial.com]

Paul, I don't understand much about phone system but I know that in britain too, they use 2 wires in residential phone sockets. About 10 years ago I worked on a phone system in Britain and it used 3 wires. One, I believe was for the ringing. Can you explain to me more about the differences, how it works and why it changed to 2 wires?

[This message has been edited by Belgian (edited 11-03-2002).]
Posted By: C-H Re: Telephone - 11/03/02 09:31 PM
[Linked Image from i.kth.se]

Two or sometimes four-wire. Four wires are used to prevent eavesdropping. (If you have picked up one phone, the other phones on the line are "dead")

The plastic pin has to do with this too. When inserted it loops the feed-through via the phone (or other equipment) inserted. Imported two-wire modems and phones give you problems when you want both phone and modem on same socket. Phones are not my cup of tea, really. Therefore I doubt I can answer any questions.

As you can see, they accept RJ-11 plugs. However, the trusted old "Rikstelefon"-sockets remain the standard in new construction, despite serving only as RJ-11 adapters.

For some reason RJ-45 has now caught on as phone plug. I installed RJ-45 sockets for this use a few years ago, when they were not normally used for this purpose. Today you can buy RJ-45 extension reels.

[This message has been edited by C-H (edited 11-03-2002).]
Posted By: Hutch Re: Telephone - 11/03/02 09:56 PM
I've posted this before so sorry for the repeat at https://www.electrical-contractor.net/ubb/Forum9/HTML/000063.html . Here is the old (pre-1990) South African standard. There are six contact surfaces: The outer pair are line 1 and the inner pair line 2. I assume the intermediate pair (not connected in the photos) would be line 3.

[Linked Image from elkonv.com]

[Linked Image from elkonv.com]

RSA now used the US standard as found on the back of your PC.

As PaulUK mentioned in the thread referred to above, it is similar to the older Australian phone jacks (these appear to have an extra pin with an additional pair of contacts that makes the design asymmetric). I was lucky enough to get a look at one of those in situ recently.


[This message has been edited by Hutch (edited 11-03-2002).]
Posted By: C-H Re: Telephone - 11/03/02 10:09 PM
Deleted post on phone dials.


[This message has been edited by C-H (edited 11-04-2002).]
Posted By: Hutch Re: Telephone - 11/04/02 02:18 AM
C-H,

Did you change your dial rotations when you switched road sides in the seventies? You yielded to the dark side of the force!

[Linked Image] [Linked Image] [Linked Image]

[This message has been edited by Hutch (edited 11-03-2002).]
Posted By: Texas_Ranger Re: Telephone - 11/04/02 02:05 PM
You guys sure you don't mix up stuff here? I don't want to be impolite, but I think it was New Zealand dials that were backwards, not British.
And what's that stuff about Sweden having changed road sides in the 70es??????
I thought the last European country to change was Austria after Hitler occupied it in 1938!
Posted By: C-H Re: Telephone - 11/04/02 02:39 PM
No, the dials haven't changed. But, yes, we did change side of the road in 1967 after a referendum where the vast majority of people voted for not changing (!)

But the cars have always had the steering wheel on the left hand side. Buses used to have it on the right hand side. (Have you noticed that we try to make things differently here? [Linked Image] )

[This message has been edited by C-H (edited 11-04-2002).]
Posted By: SvenNYC Re: Telephone - 11/04/02 03:09 PM
I have a British-made phone here. The dial is similar to a standard American phone (it spins clock-wise with the numbers on the left side).

What is notable is the abscence of the letters that go with digits 2-9 (you know, like ABC-2, DEF-3, GHI-3, etc.).
Posted By: C-H Re: Telephone - 11/04/02 03:47 PM
I went to check on old phones. They have the same dial as the British. [Linked Image]

Where have I seen one that was reversed? Perhaps my mind has been playing tricks on me...

This just goes to show that I should always check before I write. I'll better call the doc and ask him to prescribe something...
Posted By: Texas_Ranger Re: Telephone - 11/04/02 07:26 PM
No, you read it about British phones imported to New Zealand and fitted with a backwards dial. It spins the same direction, but the numbers are the other way round.
Posted By: pauluk Re: Telephone - 11/04/02 10:30 PM
C-H,
Are you sure that all the Swedish dials were the same as British? [Linked Image]

I've never come across a genuine old Swedish phone, but I've always been led to believe that zero was at the opposite end of the dial. The NZ dial had zero in the same place as the U.K., but went backwards on all the other digits: i.e. going counter-clockwise:

British/American: 1-2-3-4-5-6-7-8-9-0
Swedish: 0-1-2-3-4-5-6-7-8-9
New Zealand: 9-8-7-6-5-4-3-2-1-0

You can see this reflected in some of the choice of codes. For example, London was assigned STD code 01 as being the shortest to dial. Auckland got 09 as being the quickest on the NZ dial.

I'd always assumed that the Swedish emergency number 90-000 was also assigned at least partly because all those zeros would be fairly quick to dial. (Compare also the NZ emergency code 111, which in terms of dial pulses is exactly the same as the British 999).

Phones here did have letters on the dials years ago. They were used as the exchange prefix in London and some other large cities, and within STD (Subscriber Trunk Dialing) codes. They were phased out by 1970 or thereabouts, after which the letters were dropped from the dials. Evidence of the system can still be seen in area codes and some prefixes today.

The letter assignments differed from those used in America slightly though.
1 (none)
2 ABC
3 DEF
4 GHI
5 JKL
6 MN (UK), MNO (USA)
7 PRS
8 TUV
9 WXY
0 OQ (UK), Operator (USA)



[This message has been edited by pauluk (edited 11-04-2002).]
Posted By: pauluk Re: Telephone - 11/04/02 10:48 PM
Quote
Paul, I don't understand much about phone system but I know that in britain too, they use 2 wires in residential phone sockets. About 10 years ago I worked on a phone system in Britain and it used 3 wires. One, I believe was for the ringing. Can you explain to me more about the differences, how it works and why it changed to 2 wires?

Belgian,
The current British arrangement (introduced about 20 years ago) still needs 3 wires to each phone, although as in practically every other country the line from the house back to the exchange is only 2 wires.

Two of the lines to each jack are connected directly to the tip and ring of the incoming line (called the "A" and "B" wires here). The third line is wired to the B-wire via a capacitor and provides a separate feed to the ringer on each phone, the other side of each ringer being commoned to the A-wire.

Telephone jacks in residential work are most commonly wired with 4-core cable. The fourth wire is generally connected at the jacks, but is spare.

Have a look here for the wiring diagrams and some pictures of the plugs and sockets.

Prior to this system, single phones were most often hardwired to a junction box. Where a phone needed to be used at more than one location, we had a system of 1/4-inch Post Office jacks (follow the "Plug 420" link from the above link).

The wiring on these was different to that used in the modern system.


[This message has been edited by pauluk (edited 11-04-2002).]
Posted By: C-H Re: Telephone - 11/05/02 08:54 AM
You are 100% right, Paul! I went home and had a really good look at my phone. The position of the zero was what confused me from the start.

This also explains the problem a friend of mine had with his pulse dial phone. It has buttons, not a dial. When you dialed a phone number you ended up at someone with a number displaced one position:

445533 became
334422

(or if it was the other way round)

We eventually managed to set it to tone dial.
Posted By: pauluk Re: Telephone - 11/07/02 10:03 PM
The international problem was another reason for dropping letters from dials. Calling ACOrn 1234 or HOLborn 9876 from a phone within London, or within the UK was fine, but imagine the trouble it would have caused placing a direct-dialed international call to one of these exchanges from North America.

By the way, some of the very early automatic exchanges (i.e. turn of the century) in America used phones with an 11-hole dial. The extra position was marked "Long distance" and stepped the selector to an 11th level for accessing an operator.
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