ECN Forum Forums General Topics of the Trade Non-US Electrical Systems & Trades A common telephone connector

There seems to be 2 different types of UK > IRL adaptors on the market they're both very small white boxes with an RJ11 on a 4cm cable and BT socket.

I'd suspect that the cheaper ones just connect the 2 line cables to the correct pair on the BT socket ignoring the ring wiring.

The more sophisticated version with its own capacitor is prob. better able to cope with any standard RJ11 sockets carrying the line on the centre pair. It would work fine in the USA, Ireland, Spain or anywhere else.

Some of the circuitry in the Irish sockets is used for automatic line testing. Irish Alcatel and Ericsson exchanges seem to run a regular overnight test cycle presumably to ensure that the loop is intact / working. We had DIY wiring hooked up in the US style and at about 3am every night all the phones would ring once!

As for the dial tones etc. The Irish network didn't really follow the same development pattern as the UK and used different equipment manufacturers to BT. Many of the tones and codes would be more like France than the UK

Originally most of the automatic switching was based around Ericsson ARF crossbar, more like scandinavia/other parts of europe. in the UK it would have been stowger step-by-step & various british systems.

from 1981-1985 all of the older generation equipment was removed and rapidly replaced by one of two digital switches ; Alcatel E10 and Ericsson AXE, some of the local crossbar switches installed in the 1970s remained through the 1980's but were relatively sophisticated and "parented" by the nearest digital switch. By about 1990 they were all replaced. The trunk network was fully digital by the mid-80s though. At the time telecommunications investment was seen as absolutely vital to developing the economy.

You'll notice a lot of french features in the system.
Dial tone, progress tone (bebebebe) if the system is waiting for a call to switch (e.g. phoning a mobile / abroad)

minitel was even introduced in the 1980s although it flopped rather badly.

even the first generation cardphones were identical to some of the France Telecom ones.

Eircom's audio samples of network tones probably from an Alcatel E10 switch: http://www.eircomlab.com/audio/narrowband.htm

Sorry about the double post! I must have clicked submit reply twice opps!

No problem, I've deleted the duplicate.

I hadn't realized that crossbar switching was used so widely in Ireland. I'd always assumed that SxS would have been the mainstay of Irish telephone exchanges, as it was in Britain. A wrong assumption of my part, as Eire was independent by the time automatic switching was widely installed.

Unlike the U.S. and some other countries, Xbar never really caught on in a big way in the U.K. There were a few local exchanges that adopted it, often as trials, but it was largely confined to large tandems. In many areas the local central offices went straight from SxS to TXE (Electronic), or even from SxS to System X (digital).

Do you know when Irish STD was introduced?

The history of the telecommunications network over here is a little different.

There were some SxS exchanges in the old P&T network but as far as I'm aware they were confined to local switching and would have been of a very old vintage dating back to the 1930s. There were definitely a few in Dublin and possibily in Cork etc.

Ericsson ARK and ARF crossbar systems seem have made up most of the network in the 60s and 70s though. I don't think we ever had any electronic (non-digital) switches.

The upgrade to digital appears to have followed this route:

SxS, any remaining manual and other switches went straight to Alcatel E10 digital switching in the early to mid 1980's

Ericsson ARF switches seem to have had an upgrade path to AXE digital switching so sites that were ARF seem mostly now to be AXE.

It works out that 50% of the exchanges are Alcatel E10 based and 50% are Ericsson AXE 10 based.

As for the backbone of the network I'm not 100% sure what's used for major trunk switching although I know that they only use Ericsson and Alcatel switches. Recently eircom has invested pretty heavily in "Ericsson Engine" . VPN, 1800 etc and Chargecard is all AXE based.

As for STD it was available for many years between major population centres but some very remote spots would have gone straight from manual switching to AXE or E10 in the early 80s so I guess that 100% nationwide STD didn't become available until then.

If you look around the countryside here you'll see small prefabricated green containers with airconditioning units on top (usually near a post office). They contain an Alcatel E10B that would have replaced manual switching directly!!

The Alcatel E10 (identical to most of France Telecom's network) and Ericsson AXE switches have been pretty heavily modified and upgraded over the years so they're still pretty much cutting edge and provide the full raft of services.

Thanks for that -- Interesting history. I've never been able to track down much detailed information about the development of the Irish telephone network.

Small villages in the U.K. were often served by a GPO-designed UAX (Unit Automatic eXchange), a small SxS switching system housed in a "cottage" style building.

In places which finally outgrew the UAX you often see a larger early-1970s exchange housing TXE within a few hundred yards of the old building. The old UAX buildings are still there in some villages, serving as small homes, doctors offices, etc.

For those unfamiliar with small English villages, let me point out that most UAX systems had only 3-digit local numbers and even by the end of the 1970s some of these had assigned numbers only in the 2xx and 3xx ranges, i.e. less than 200 subscribers!

By the way, DJK, which part of Ireland are you in?

Here's a full explanation of BT versus Eircom wiring and what happens when you plug a UK modem into an Irish phone socket ... (no dialtone)
http://members.toast.net/leslie/testpage/wiring.htm

Thankfully WiFi (Airport/WaveLAN etc) should put an end to all this stuff as more and more hotels and public spaces get wireless LANs installed