Wanted...mobile phone ...subject matter ends way o

Fidgits · June 17, 2003

Hi, last night my mobile phone went for a swim

I am trying to dry it out, without much success, so if anyone has a tri-band Ericsson for sale, please let me know, as I may be interested in buying it off you.

rhaines · June 17, 2003

I won't even ask who you were talking/listening to or what you were doing while it was that close to the water....

:P :D

Fidgits · June 17, 2003

I was on a 2 hour conference call, and decided to make a coffee... as I filled the kettle, the phone slipped from my shoulder/ear into the sink... which was full of water

And becuase it's a T39, all my buisness numbers are stored on the phone not the sim!

Scorpion · June 17, 2003

Sorry to hear that mate but funny how we insure our.............

lives,house,contents,car the list goes on but not the mobile

LET THIS BE A WARNING!!!

Fidgits · June 17, 2003

I thought it was insured... except when i called them, they said it wasn't part of the package.

:tsktsk: At 500 quid a month, you'd think they'd include a 4 quid insurance charge for me wouldn't you!

Fidgits · June 17, 2003

Zee... I make international calls all day long...

And every week I end up spending 4 hours on our company conference call (to the US).

Although, I am going to look around in October when it's due for renewal, i just need to keep my number.

Fidgits · June 17, 2003

so which provider do you use??

(my bills been around 500 since i started this job??)

Fidgits · June 17, 2003

so which provider do you use??
(my bills been around 500 since i started this job??)

Company used to have a contract with Vodafone, but have recently switched to 02. Hundreds of minutes free (for mobiles, local and national) and international calls are very cheap (Europe and Stateside).

I will ask about the tariff if you are interested....

Yes please, because (strangely) I have a Vodafone contract through O2 (don't ask), so i might be able to change it asap...

Thanks Zee

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IF YOU VALUE YOUR SANITY ........ STOP READING HERE.......

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Edited June 17, 2003 by Fidgits

insider · June 17, 2003

try ur home insurance claimed of mine when the baby decided to play boats with mine in the bath that was an erickson r380 world they payed up for a p800 which was cool didnt even want the old phone as proof just a thought :P

TonyGoose · June 17, 2003

You guys may be interested in a radical new phone service ...

It uses 'wires' to transmit calls through a series of exchanges.

You won't believe how much cheaper than mobile calls it is too

Tried and tested for decades and available nationwide through BT and others i believe :D

It never ceases to amaze me the number of people round where i work ...

who routinely use mobiles while sitting next to a perfectly good deskphone ....

AND THEN winge and moan like hell about the size of their mobile bill :iraqi-info-minister:

Derrrr :duh: :iraqi-info-minister: :iraqi-info-minister:

:D :D

Monster-Mat · June 17, 2003

and for those that went to the cotswolds meet heres something.....................

In 1974 Stow could still be found in the dialling instructions, but it was soon to vanish from the list and together with Bourton-on-the-Water and others was to form the Cotswold group of exchanges (STD code 0451). The exchanges and equipment on the ground remained in place of course. Stow remained electro-mechanical almost until the end of Strowger in the UK. The racking, stripped of its equipment, is still in place and can be glimpsed through the windows. The building is a smaller version of the one at Chipping Norton. The flat-roofed section to the right houses toilets and mess room.

rhaines · June 17, 2003

I missed that...

Little telephony history lessons :)

Monster-Mat · June 17, 2003

Telephone exchanges

What types of exchange are there, and which can be digital ?

The types are

Strowger - rotary switches, etc (UAXs, SAX, TXS)

Electromechanical crossbar (TXKs)

Electronic-control reed-relay switches (TXE2)

SPC non-digital (TXE4*)

Digital (Systems X and Y - AXE10: may be further categorised as to whether they're ISDN-capable, I suppose; 5ESS; DMS100; UXD5.)

The last crossbar and Strowger exchanges have now been removed from service.

The UXD5, a public-exchange variant of the Monarch digital PABX, probably remains only in the Highlands of Scotland and rural Wales.

You can tell whether you have an electronic exchange by trying to dial a number with DTMF dialling. If you get unobtainable when you dial * or # then you have an electronic one, but not digital.

On TXE4(RD) exchanges (the original design), a change to the class-of-service threading is needed to enable DTMF. The TXE4A (with a newer design of processor and register) has DTMF enabled for all lines.

Dial *#001#. If you get "No services are in operation on this line" or a list of services, you're System-X. If you get "Sorry, you have dialled an invalid service code" it's AXE10.

Also, *55* will prompt you for a time on System-X; it won't on AXE10. If you get Number Unobtainable, you're not on a digital exchange. If you still have dial tone, you're on an "old technology" exchange. If you hear nothing (except crackling in your case) you're probably on an Ericsson (System-Y)

Now, type (a) accepts your dialling at the point in the switching matrix that your call has so far reached. Every switch has its own dial pulse decoding and routing intelligence. Short of generating the dial pulses at the MDF (where the lines come into the exchange), there's no way to convert them to DTMF. And what would be the point? - pulsing dial pads are _so_ cheap that pretty much everyone's telephone can do the job.

All but type (a) accept the digits you dial into a register, and make the routing decisions centrally based on the contents of the register. In principle, any such exchange can easily be converted to accept DTMF: it simply requires a different input box for the register.

(Historical note: the first electronic research exchange to hit public service in the mid-60s, the TXE1 at Leighton Buzzard (RIP) was DTMF capable. As a person involved with fiddling 'phones at the time, I arranged to go round it with some like-minded friends: we were shown a DTMF 'phone in the exchange manager's office, and were told that there was precisely one `public' user of the service.)

Pretty much any SPC exchange (types (d) and (e)) can in principle offer network services. We know that type (d) can in some cases, since we've had a post to that effect from someone at STC (was it - sorry, I've forgotten your name). We know that type (e) can do it, since they all do...

Five designs of digital exchange are being installed. System X, AXE 10, UXD 5, 5ESS PRX and DMS100. System X is an all-British family of digital exchanges manufactured by GEC Plessey Telecommunications (GPT); AXE 10 is a Swedish design and manufactured in the UK by Ericsson Telecommunications Ltd; UXD 5 is a small system specifically devleoped by BT for rural areas, and 5ESS PRX is the European version of a system developed by the American company AT&T and widely used in North America. The DMS100, designed and built by Northern Telecom (NT) is being used for Featurenet services.

The last analogue switch was removed from the trunk network in June 1990. All traffic on the trunk network is now handled by 59 fully interconnected Digital Main Switching Units (DMSUs) and four partially connected Digital Switching Units (DSUs) which help handle high call volumes from between London and the Home Counties. International traffic is handled by 4 dedicated exchanges.

At the local level, around 97% of customers are connected to digital or modern electronic exchanges.

At 30th September 1993, BT operated 7,537 local exchanges in the UK, comprising 5,532 digital, 1,301 electronic, 38 crossbar and 666 Strowger (electromechanical). By March 1996 all customers will be served by modern electronic exchanges.

What is the difference between a System X and System Y exchange ?

System X was a co-operative development by Post Office Telephones, GEC, Plessey and STC. There was a big bust-up in which STC were removed (and given exclusive rights to supply TXE4) and GEC and Plessey were given all the rights and obligations to develop System X as a commercial system which BT would then buy by competitive tender.

It was decided that there should be at least TWO suppliers to the PO/BT, and there was a large international tender to decide on a second, competitive system. Ericsson made the AXE10 which offered practically the same flexibility in a smaller box (mainly because System X was designed by committee: it was already dated before the first release model became available). The AXE10 was chosen and was then (and still is) bought by BT in competition with System X. The AXE10 became BT's 'System Y' just to keep things 'simple'.

If anything the AXE10 is more full-featured than the 'X' but BT only took the basic software package on each, so both offer practically the same. Incidentally, Cellnet tried to use System X as their mobile switch but dumped it as it was very old tech. Vodafone tried Ericsson, and that is why Vodafone runs totally on AXE10s.

Monster-Mat · June 17, 2003

and a few things you never knew your phone could do..............

What is the number that will dial my 'phone back to test the ringing?

Dialling 174 on modern electronic exchanges.will make the exchange ring back when you put the phone on hook.

On a System X/Y dialling 177 will make the exchange read out your number, and dialling 175 will produce the exchange test...

A replacement for both 174 and 175 has also been mentioned, which is

17070

Ringing 17070 results in

"This circuit is defined as <number> " and then " BT line test

facilities, please press 1 for ring-back test or clear down."

Keying 1 then results in

"BT ring-back test, please clear down."

After a few seconds, phone rings, and announcement is

"BT ring-back test completed."

When I called 175 from home there was a message telling me my phone number, then when I hung up I was called back and offered a mysterious menu. Anyone know how to work it?

1. Dial 175

2. Exchange answers and says "You are connected to <number>. Start test."

3. Hang up

4. Exchange calls back and says "line testing ok" (assuming it is ok, of course). Then it enters a loop, inviting you to "dial next test" and performing a test based on the single-digit code you give it. From memory, test 1 is the keypad test (dial 123456789*0#) and 3 is the coin pulse test.

Exchange Test Numbers

Abbreviations

SPM = Subscriber Pulse Metering FRB = Ringback Test

CPI = Cable Pair Indicator (Loud tones on line to identify cable)

LPI = Line Pair Indicator (Gives telephone number connected to)

SALT = Subscriber automatic line test

TXE4 - Electronic Equipment:

SALT Dial 175 and wait for "Start Test" message

Replace handset. Rings

Message: "Line Testing Ok" or fault if present.

Continue, wait for dial tone for dial test.

Dial 1 3 0 5. Rings. Message "Testing Ok" or fault if present

FRB Dial 174

LPI Dial 188 gives directory number & equipment, or if not,

Dial 187 gives equipment number.

CPI 176 plus full national code (i.e. 176 081 553 7104)

Tone is present on line when dialled. Replace receiver

to cancel tone.

TXD-X - System X Equipment

SALT Dial 175

FRB Await ringback and listen for message.

Continuation tests. Await interrupted dial tone.

Dial "1" for dial test. On LD phone, dial 1-0.

On MF phone, dial 1-9*0#.

Dial "4" for SPM test. 10 metering pulses are sent, then

NU tone, followed by 10 more pulses.

CPI Dial 176 plus full national code (i.e. 176 081 553 7104)

(This will only work from same processor)

Wait for short burst of tone reminder, then tone is transferred

to the specified line. To disconnect tone, replace handset.

TXD-Y - System Y Equipment

SALT Dial 175

Await ringback and listen for tone.

Dialtone=OK Engaged=Suspect Faulure=Fault

Dial next test if required, tests as follows:

2 Low A/B Insulation test |

3 A/B to earth | Insulation tests

4 A/B to Battery |

5 A/B loop to earth |

9 Bell answer before 5th ring

11 SPM test

7 Loop Res test

8 Dial test. LD Dial 0. MF Dial 1-9 0

10 Rec all pre

6 Line reversal for diode check

Dialtone=OK Engaged=Suspect Faulure=Fault

FRB 174

What do the various messages from the 175 tester on System X really mean, eg. "Earth A, Battery B"?

A-wire (leg) - connected to earth at the exchange via effectively a current source.

B-wire (leg) - connected to negative 50v at the exchange likewise.

Looking from the exchange, there should be a large resistor (100k I think), across 2microfarads, and a slice of resistance in series (1k nominal at dc) - the bell. (the 100k is only on new lines)

Earth or Battery A, as reported by the tester is a fault. it should be isolated totally. Earth or Battery B likewise.

Low resistance A to B likewise again.

Each indicates a weak insulation, and it depends on what path the weakness has allowed. other exchange lines around it are still connected, to earth and -50v after all ...

Is there a way I can pulse-dial a digital exchange number and then tone dial from there?

Well, if you are not in an area served by Mercury, I would think the only way to do this would be with a BT ChargeCard - you pulse dial the "144", and can tone dial from then on.

All BT payphones switch to tone dialling as a matter of course, after receiving a metering pulse. Most dual-equipped phones, if switched to pulse dialling, will change over to tone dialling by pressing the '*' key. Operator and non-payment numbers (144, 0800) do not switch.

The main snag, (apart from the extra delay caused by entering your ID and PIN), is that you then have to pay for your call at call-box rates (8.5p/unit +VAT instead of about 4.2p +VAT).

--------------------------------------------------------------------------------

Fidgits · June 17, 2003

Just to put this thread back on topic...

I spoke to the phone company, and they have been great, and are shipping me a new phone free of charge (a good one too :D )

Monster-Mat · June 17, 2003

sorry........

but who actually read the info above......some of its quite intresting

Monster-Mat · June 17, 2003

i know

but you have one coming now......... :winky:

djanderso · June 17, 2003

I've lost the will to live after reading all that!

:P

Monster-Mat · June 17, 2003

when Jim Wallace comes along he can tell us more................. :D

rhaines · June 17, 2003

Now you have a phone, back to the history....

UK Telephne history can be found here

Monster-Mat · June 17, 2003

Location of British Telecom Telephone Exchanges

ALB-Nl Newington Green TSVC, 21 Albion Road, Newington Green, London N16 9QI

ALB-SE Hampton House, 20 Albert Embankment, London SE1 7TL

ALD-GU Aldershot TE, Ordnance Road, Aldershot, Hampshire GU11 2AH

ALM-SO 6 Alma Road, Romsey, Hampshire S05 8ED

ALS-SE 1-8 Alaska Street, London SE1 8UG

ANG-EC The AngelCentre, 403 StJohns Street,London EC1 4PL

ASH-AL St Albans TSVC, Ashiey Road, St Albans, Hertfordshire AL1 5JS

ASH-N2 Ashley House, 235-239 High Road, Wood Green, London N22 4HP

ASH-TW Ashford PMC, Shed 1, Ashford Hll Road, Ashford, Middlesex TW15 1HE

ATE-CR Croydon ATE, Teevan Road, Croydon, Surrey CR9 6DL

AVE-SE New Eltham Depot, 1 Avery Hill Road, London SE9 2BB

AVN-RG Avonbank House, 1 Pembroke Road, Newbury, Berkshire RG13 lBZ

AYL-ME Aylesford ATE, High Street, Aylesford, Kent ME20 7AZ

AZH-IP Anzani House, Trinity Avenue, Felixstowe, Suffolk IPI1 8XB

BAS-WC Bastion House, 31-34, Bow Street, London WC2B 5HL

BAT-EC Bath House, 52 Holborn Viaduct, London EClA 2ET

BAT-SW Battersea TE, 60-62 Altenburg Gardens, Lavender Hill, London SW11 lJN

BAY-EC Baynard House, 135 Queen Victoria Street, London EC4V 4AT

BCK-BR Chislehurst TE, Bickley Park Road, Chislehurst, Bromley, Kent BRl 2BH

BCK-CT Becket House, New Dover Road, Canterbury, Kent CTl 3BB

BCK-HG SpaTEC, Back Royal Parade, Harrogate, North Yorkshire HG3 ONG

BDD-MK Bedford ATE, Harpur Street, Bedford, Bedfordshire MK40 1RA

BEC-SE Becket House, 60-68 St Thomas Street, London SE1 3QU

BET-Nl Power Section Workshops, Betstyle Road, New Southgate,London N11 1JA

BEU-SE Beulah Hill TE, Church Road, London SE19 2QN

BIL-EN Bilton Way, Enfield, Middlesex EN3 7PD

BLC-SE 19-23 Biackfriars Road, London SE1 8NY

BLK-NW West Hampstead TSVC, Blackburn Road, West Hampstead, London NW6 lRZ

BLK-WF Batley ATE, Blakeridge Lane, Batley, West Yorkshire WF17 8PD

BLL-NW 30-34 Bell Street, London NWl 5BU

BLT-SW Earls Court, The Boltons, Old Brompton Road, Earls Court, London SW10 9TB

BLT-W5 Bilton House, 54-58 Uxbrldge Road, Ealing, London W5 2TL

BLY-W4 Chiswick TE, Barleymow Passage, Chiswick, London W4 4PL

BNT-RG Basingstoke TE, Bounty Road, Basingstoke, Hampshire RG21 2BX

BOV-HP Bovingdon TE, Hyde Lane, Bovingdon, Hemel Hempstead, Hertfordshire HP3 OEF

BRD-AL Welwyn Garden City TSVC, 73 Bridge Road East, Welwyn Garden City, Hertfordshire AL7 1JL

BRD-BR Bradway House, 3 High Street, Bromley, Kent BRl lLF

BRD-SW Westminster ATE, 1A Broadway, Westminster, London SW1H OAY

BRD-TN Tunbridgewells TEC,Broadwater Lane,Tunbridgewells,KentTN2 5RE

BRD-UB Southall Assembiy Centre, Unit A, Bridge Road, Southall, Middlesex UB2 4AB

BRD-W1 Bird Street TE, 8-13 Bird Street, London W1M 6AD

BRD-W5 Broadwalk, 54 The Badway, Broadway Centre, Ealing, London W5 5JY

BRH-SM Burgh Heath ATE, Garrats Lane, Banstead, Surrey SM7 2EE

BRK-B1 Berkley House, 245 Bload Street, Birmingham, West Midiands B12 HQ

BRK-EC Broken Wharf House, High Timber Street, London EC4 3DL

BRL-RG Newbury ATE, Bear Lane, Newbury, Berkshire RG14 5QR

BRN-EN Barnet TE, 5-15, Leicester Road, New Barnet, Hertfordshire EN5 5EP

BRN-IG Barking TE, 62 Vctoria Street,, Barking, Essex IGll 8JE

BRN-N1 Palmers Green ATE, 2 Bourne Hill, Palmers Green, London Nl3 4LG

BRN-NW Burne House, Bell Street, North Paddington, London NWl SBZ

BRT-EC 43 Bartholomews Close, LoDdoD EClA 7HP

BRW-SE Bear Wharf, 27 BaDkside, London SEl 9BA

BRX-SW Brixton TE, 45 Gresham Street, London SW9 7NU

BSN-RG Reading Trunk Exchange, 11 Basingstoke Rosd, Reading, Berkshire RG2 OEW

BST-ME Medway Exchange, Best Street, Chatham. KeDt ME4 4AB

BTC-EC British Telecom Centre, 81 Newgate Street, London EClA 7AJ

BTH-BH Bournemouth TE, 18-20 Bath Road, Bournemouth, Dorset BHl 2NR

BTH-TW Skyport TE, Bath Road, Hounslow, Middlesex TW6 2DU

BTL-KT Walton On Thames TSVC, Badey Court, Rydens Road, Walton-on-Thames, Surrey KT12 3BU

BTT-W1 British Telecom Tower, 60 Cleveland Street, London WlP 6EA

BUN-EC Bunhin Row OAC, 103-105 Bunhill Row, London EClY 8LR

BUS-N1 Unit B, Bush Industrial Estate, Station Road,Tufnell Park, London Nl9 5UW

BXL-DA Bexleyheath TE, 313 The Broadway, Bexleyheath, Kent DA6 8DU

CAL-EH Caledonian House, l9a, Canning Street, Edinburgh, Scotland. EH3 8TA

CAM-SE Camelford House, 87 Albert Emhankment, London SE1 7TS

CAM-UB Southall TE, Cambridge Road, Southall, Middlesex UBl 3BH

CAN-N5 Canonbury TE, 1-3 Highbury Grove, London N5 1HG

CAP-EH Capital House, 2 Festival Square, Edinburgh, Scotiand EH3 9ST

CAR-EC Caroone House, 14 Farringdon Street, London EC4A 4DX

CAT-SE Catford TSVC, 2 Fordmill Road, Catford, London SE6 3TH

CAV-EC Cavendish TE, 107 Houndsditch, London EC3A 7NB

CAX-EC Caxton House, 2-12 Farringdon Road, LDndon EClM 3LU

CCC-AB City Communications Centre, 9 Bridge Street, Aherdeen, Scotland. AB1 2JL

CDH-WC Control Data House, 179 Shafteshury Avenue, London WC2H 8AR

CFD-DA Crayford TE, Southworld Road, Crayford, Bexley, Kent DA5 1LZ

CFD-W1 West End EPMC, 6-7 Cillford Street, London WlX 2DJ

CGY-EC Barbican Computer Centre, 26/28 Glasshouse Yard, London EClA 4JY

CHC-RG Caversham TE, 15 Church Street, Caversham, Reading, Berkshire RG4 8AZ

CHE-KT Chessington TSVC, Cox Lane, Chessington, Surrey KT9 1TX

CHL-BR Orpington TE, Chislehurst Road, Orpington, Kent BR6 OBD

CHP-EC Cheapside House, 138 Cheapside, London EC2V 6JH

CHR-KT Chertsey TE, Guildford Street, Chertsey, Surrey KT6 9AA

CHS-EC 5 Cheapside, London EC2V 6AA

CHS-RH Chesterfield Park, Buckland Road, Reigate, Surrey RH2 9TB

CHS-SW Belgravia TE, 21-24 Chesham Piace, London SWlX 8HG

CLA-CO Ciacton Word Processing Centre, 103-105 Carnarvon Road, Ciacton-on Sea, Essex CO15 6PR

CLC-RM Ingrehourne TE, Colchester Rosd, Harold Wood, Ingrebourne, Romford, Essex RM3 OXD

CLL-OL Rochdale TE, 2 College Road, Rochdale, Grester Manchester OL12 6RZ

CLM-SE Columbo House, Joan Street, London SEl 8BE

CLN-N1 Coppetts TSVC, Colney Hatch Road, New South Gate, London Nll 3DG

CLN-NW Colindale House, The Hyde, Edgeware Road, Colindale, London NW9 6HH

CLN-RH Redhill OAC, 22 Clarendon Rosd, Redhill, Surrey RHl lDY

CLR-CB Clarendon House, Clarendon Road, Cambridge, Cambridgeshire CB2 2BA

CLR-CO Information Systems Unlt,9 Clarendon Way,Colchester,Essex COl lBE

CLT-EC 29 Clothfair, London EClA 7JQ

CLW-EC Clerkenwell ATE, 1 Ironmonger Row, London ECI 3QN

CML-NW 103 Carmley Street, London NWI 0PU

CMM-E1 Stepney Green TE, 419-425 Cormmercial Road, Stepney Green, London El OHA

CMM-SY Communications House, Harlescott Lane, Shrewsbury, Shropshire SYI 3AQ

CNG-El Canning Town TSVC, Stephenson Street, Canning Town, London E16 4SL

CNH-SW Chantrey House, 4 Eccleston Street, London SWlW 9LN

CNN-HA Pinner ATE, Cannon Lane, Plnner, Middlesex HA5 1JL

CNS-KT Chessington TE, Coniston Way, Chessington, Surrey KT9 IED

COM-HX Halifax ATE, Commercial Street, Halifax, West Yorkshire HX1 IBT

CON-SW Connect House, 133-137 Alexandra Road, London SW19 7JY

CRD-EC Cardinal House, 12 Farringdon Road, London EClM 3ND

CRD-RG Reading CC, 128-130 Cardiff Road, Reading, Berkshire RGI 8PQ

CRG-EH Capital TE, 357 Gorgie Road, Edinburgh, Scotland EH14 2RP

CRG-SW Whitehall TE, 6 Craigs Court, Whitehall, London SWlA 2DB

CRG-SY BT Radio Station Criggion, PO Box 2, Oswestry, Shropshire SY10 8PA

CRO-CR Croydon ATE, Scarbrook Road, Croydon, Surrey CR9 lXL

CRT-PO Portsmouth TEC, Court Lane, Cosham, Portsmouth, Hampshire PO6 2LL

CRV-W5 Ealing TSVC, 1 Craven Road, Ealing, London W5 2UA

CRY-BR Common Service Centre, Cray Avenue, Orpington, Kent BR5 3QF

CRY-DA Crayford TSVC, 158-160 Crayford Road, Crayford, Kent DA1 4ES

CRY-SE Sydenham TE, 2 Crystal Palace Park Road, Sydenham, London SE26 6EF

CSH-PO Cosham Trunk TE, Vectis Way, Cosham. Hampshire PO6 3AN

CST-Wl Castle House, Gordon Road, London W13 8QD

CTG-E7 City Gate House, 246-250 Romford Road, Forest Gate, London E7 9HZ

CVH-UB Cave House, Osborne Road, Uxbridge, Middlesex UB2 2TT

CWD-CO Colchester TEC/MTW, Cowdray Avenue, Colchester, Essex CO1 1YD

DAR-DA Dartford DAC, Suffolk Road, Dartford, Kent DA1 1EH

DCS-E1 Docos House, 62-82 Commercial Road, London E1 1NR

DEF-EC Defoe Court, 44 Feathertone Street, London EC1Y 8RN

DGL-SW Regency Street TSVC, 8-14 Douglas Street, London SWlP 4PD

DHH-EC Dowgate Hill House, Dowgate Hill, London EC4R 2SU

DKS-SO Dukes Keep, Marsh Lane, Southampton, Hampshire SO1 1EX

DLH-WC Dial House, 151 Shaftesbur Avenue, London WC2H 8BA

DLT-CR Delta Point, 35 Wellesley Road, Croydon, Surrey CR9 2YZ

DNS-LN Danesgate House, Grantham Street, Lincoln, Lincolnshire LN2 1BA

DNS-LU Luton ATE, Dunstable Place, Luton, Bedfordshire LU1 1QD

DRK-G4 Casdemilk TEC, 179 Drakemire Drive, Castlemilk, Glasgow, Scotland G45 9SS

DRR-WC Dury Lane TSVC, 141-143 Drury Lane, London WC2 5TB

DRY-SW South Kensington TE, 76 Draycott Avenue, South Kensington, London SW3 3AB

DUL-SE Dulwich TE, 512 Lordship Lane, East Dulwich, London SE22 8NF

EDH-SE Edinburgh House, 154-182 Kennington Lane, London SE11 4EZ

EDS-BR Bromley TE, 1 Edison Road, Bromley, Kent BR2 OEQ

ELH-MK Elder House, 564 Eldergate, Milton Keynes, Buckinghamshire MK9 ILK

ELL-G3 75 Elliot Street, Glasgow, Scottand. G3 8EX

ELL-IG Elliot House, 6 Ilford Hill Ilford, Essex IG1 2BA

END-WC Euston TE, 30 Endsleigh Gardens, London WClH OEJ

ENF-EN Enfield ATE, 28 Cecil Road, Enfield, Middlesex EN2 6SX

ENT-RH Enterprise House, Worthing Road, Horsham, West Susses RH12 1TL

EPS-KT Epsom TE, East Street, Epsom, Surrey KT17 1BA

ERL-SE Erlang House, 125 Blackfriars Road, Saint George Circus, London SEl 8BA

ERP-TN Europa House,Church Road,Tunbridge Wells,KentTN1 1HT

ESH-KT Esher TE/AMC, Hare Lane, Claygate, Esher, Surrey KT10 9BX

EST-HP High Wycombe ATE, 17-18, Eastern Street, High Wycombe, Buckingharnshire HP11 1NR

EST-NW Euston TE, 165 Euston Road, Euston, London NW1 2BH

EST-UB Hayes North TE, East Avenue, Hayes, Middlesex UB3 2HJ

ETT-NW Euston Tower, 286 Euston Road, London NW1 3DG

EUR-EC Europa House, 13-17 Ironmonger Row, London EClV 3QN

EUS-NW Mobile House, Euston Square, London NW1 2DW

EWE-KT Ewell TE, 5 London Road, Ewell, Surrey KT17 2AY

EWL-KT Surbiton TE, 5 Ewell Road, Surbiton, Surrey KT6 6AB

EXC-RM Romford TE/GSC, Exchange Street, Romford, Essex RM11 RR

FAL-EC Falcon House, Aldersgate Street, London EClA 4ET

FAR-EC Meridian House, 34-35 Farringdon Street, London EC4A 4ED

FBR-W1 45 Fouherts Place,Regents Street,London WlV 2DN

FLD-SE Fielden House, 28-42 London Bridge Street, London SE1 9SG

FLH-SW Chelsea TSVC, 234 Fullham Road, Chelsea, London SW10 9HB

FLK-MK Faulkner House, Bletchley Park, Milton Keynes, Buckinghamshire MK3 6EA

FLM-SE Southwark TSVC, 25 Falmouth Road, Southwark, London SE1 4JH

FLT-EC Fleet Buildung, 40 Shoe Lane, London EC4V 3DD

FNC-IG Hainault TE, 358 Fence Piece Road, Hainault, Essex IG7 SDY

FNC-NW Hampstead TE, 361 Finchley Road, London NW3 6EX

FOR-HA Edgware Installation Office, The Forum, High Street, Edgware, Middlesex HA8 7 BB

FRD-B9 Fordrough Lane, Bordesley Green, Birmingham, West Midlands B9 SLD

FRD-EC Faraday Building, Queen Vlctoria Street, London EC4V 4BU

FRD-N7 Lower Holloway TE, Faraday Close, Lower Holloway Road, London N7 8EH

FRH-RG Farley Hall, London Road, Binmeld, Bracknell Berkshire RG12 SEU

FRH-SO Friary House, Briton Street, Southampton, Hampshire SO9 1BB

FRN-BR Farnborough TE, Church Road, Farnborough, Kent BR6 7DB

FRS-WD Watford TE, First Avenue, Garston, Watford, Hertfordshire WD2 6PS

FRT-EC Moorgate ATE, 72 Fore Street, Moorgate, London EC2Y SEQ

GDM-IG Goodmayes TE, 87 High Street, Goodmayes, llford, Essex IG3 8TB

GLN-UB Yeadung TSVC, Glencoe Road, Yeading, Hayes, Middlesex UB4 95J

GNH-TR Goonhilly Satellite Earth Station, Goonhilly Downs, Helston, Cornwall TR12 6LQ

GRB-BS Graham Bell, Telephone House, Queen Charlotte Street, Bristol, Avon BSl lBA

GRF-HP Aylesbury TEC, Griffin Lane, Aylesbury, Buckinghamshire HP19 3BW

GRL-N2 Winchmore Hill TE, 892 Green Lane, Winchmore Hill, London N21 2BG

GRL-RH East Grinstead ATE & TRS, Garlands Road, East Grinstead, West Sussex RH19 LED

GRN BN Grenville House, 52 Churchill Square, Brighton, East Sussex BN1 2ER

GRN-N2 Green Ridings House, 245 High Road, Wood Green, London N22 3HF

GRN-SW Pimlico TE, 34-36 Greencoat Piace, Pumlico, London SWlP lEE

GRN-UB Greenford TE, 398 Greenford Road, Greenford, Middlesex UB6 9AL

GRR-WC Gerrard Buildiung, 8/13 Lisle Street, London WC2H 7BQ

GRS-EC 2-12 Gresham Street, London EC2V 7AG

GRT-EC Monument TE, 11/13 Great Tower Street, London EC3R SEA

GRV-SM Sutton TE, 17 Grove Road, Sutton, Surrey SM1 lBA

GRY-WC Kings Cross TE, 233 Grays Inn Road, Kings Cross London WClX 8RD

GWR-WC 151 Gower Street, London WClE 6BA

HAM-W6 Hammersmith TE, Riverside Gardens, Hammersmith, London W6 9LQ

HAY-SR Hayes Common ATE, 10 Hayes Street, Bromley, Kent BR2 7LF

HDD-W1 Haddon House, 2-4 Fitzroy Street, London W1P SAD

HEN-NW Hendon West Telephone Exchange, 75 Watford Way, London NW4 3BT

HGH-EN Enfield TE, 40 High Street, Ponders End, Enfield, Middlesex EN3 4EP

HGH-WC 203 High Holborn, London WClV 7BU

HGM-E1 Highams Park TE, Brookescroft Road, London E17 4LH

HGS-SE Penge TSVC, 66 High Street, Penge, London SE20 7HB

HHL-WC Holborn TE, 268/270 High Holborn, London WClV 7EJ

HIL-SE Hill House, 133-150 Blackfriars Road, St. Georges Circus, London SEl 8BA

HLR-EC 150 Holborn, London EClN 2NS

HLC-EC Holborn Centre, 120 Holborn, London EClN 2TE

HLF-DA Sidcup TSVC, 37-39 Halfway Street, Sidcup, Kent DA15 8LH

HLL-CR Downland TE, 2 Hollymeoak Road, Downland, Coulsdon, Surrey CR5 3YH

HLL-E1 Wanstead TE, Holly Lodge, Gordon Road, Wanstead, London E11 2RB

HLL-NW Lords TE, Hall Road, Lords, London NW8 9RD

HLL-TW Hounslow TE, Holloway Street, Hounslow, MiddlesexTW3 lBD

HLN-E1 Walthamstow TSVC, Hale End Road, Walthamstow, London E17 4DJ

HLS-TN TW+Tenterden ATE, Hales Close, Tenterden, Kent TN30 6RJ

HND-EC Houndsditch TE & TSVC, 107-11O Houndsditch, London EC3A7NB

HNR-TW Annandale House, 1 Hanworth Road, Sunbury on Thames, Middlesex TW16 SDJ

HOD-EN Hoddesdon TE, High Road, Broxbourne, Hertfordshire EN10 7HU

HPS-E9 Hackney TSVC, Hepscott Road, Hackney, London E9 SHB

HCL-UB Harmondsworth ISU, Colnbrook By-Pass, Harmondworth, West Dryton, Mlddlesex UB7 OHA

HRB-E1 Harbour TE, Harbour Exchange Square, Isle of Dogs, London E14 9GE

HRN-BH Heron House, 8-10 Christchurch Road, Bournemouth, Dorset BHl 3NA

HRN-G2 Heron House, 255 St Vincent Street, Glasgow, Scotland. G2 SBA

HRR-WC Harrison Street TE, 39/40 Harrison Street, London WClV 7EJ

HTF-EN Potters Bar TE, Hatfield Road, Potters Bar, Hertfordshire EN6 lHR

HVL-TN Operator Exchange, Havelock Road, Hastings, Sussex TN34 lDQ

HYD-NW Hyde House, The Hyde, Edgeware Road, Colindaie, London NW9 6LH

HYS-UB Aeradio House, Hayes Road, Southall Middlesex UB2 SNJ

ILF-IG Peachey House, 39 Ilford Hi4 Ilford, Essex IGl 2BA

IMP-L2 Imperial Bulldings, Exchange Street, Liverpooi, Merseyside L2 3PQ

INT-SE Intel House, 24 Southwark Bridge Road, London SEl 9HJ

IVC-WD Iveco Ford House,Station Road, Watford, Hertfordshire WDl lSR

JDD-WC Kelvin House, 123 Judd Street, London WClH 9NP

JPP-E1 Stratford TE, 20-30 Jupp Road, Stratford, London E15 lAF

JRM-E1 Bishopsgate TE, Jerome Street, Bishopsgate, London El 6NJ

KEN-SE Kennington TE, Kennington Park Road, Kennington, London SE11 STP

KNG-CR New Addington TE, King Henrys Drive, Lodge HilL New Addlington, Surrey C R9 ODY

KNa-E8 Kingsland Green TE, Kingsland Green, London E8 2LA

KNG-ME Maidstone ATE, 9-11 King Street, Maidstone, Kent ME14 lAD

KNG-PO Portsmouth CTE, King Henry 1 Street, Portsmouth, Hampshire P01 2BZ

KNT-NW Kentish Town Road, 177 Kentish Town Road, London NW1 8PE

KRK-UB Kirk House, 97-109 High Street, West Drayton, Middlesex UB7 7BJ

KYB-SW Keybridge House, 80 South Lambeth Road, London SW8 1 RE

LBS-SE 20 London Bridge Street, London SE1 9SH

LCC-LS Leeds Computer Centre, 307 Dewsbury Road, Leeds, West Yorkshire LSll SUQ

LFL-OX BT College, Leafield, Oxford, Oxfordshire OX8 5PB

LFN-IG llford North, 227 Cranbrook Road, Ilford, Essex IG1 4TL

LGR-SE Lee Green TE, 133 Lee High Road, Lee Green, London SE13 SPG

LGT-IG Loughton TE, 17-19 Priory Road, Loughton, Essex IG10 LF

LHM-SE Lewisham OAC, 199/201 High Street, Lewisham, London SE13 6LY

LIL-SW Fulham TE, 84 Lilly Road, Fulham, London SW6 lTJ

LMB-SE 6 Lambeth Road, St Georges Circus, London SEl 6HU

LMP-CR Warlingham TE, Limpsfield Road, Warlingham, Surrey CR3 9YX

LNC-EN Enfield TEC, 277 Lincoln Road, Enfield, Middlesex ENl lSY

LND-EC Loodon House, 173 Aldersgate Street, Loodon EClA 4H H

LND-HA Wembley TE, Loodon Road, Wembley, Middlesex HA7 4PT

LND-PO Waterloovill ATE, 210 Loodon Road, Waterlooville, Hampshire P07 7AJ

LND-SS Southend Main TE, 221 London Road, Southend-on-Sea, Essex SS0 7BT

LNG-CB Cambridge TE, Long Road, Camhridge, Cambridgeshire CB2 2HG

LNG-KT Long Ditton Repeater Station, Avondale Avenue, Esher, Surrey KT10 ODA

LNS-EC Landsec House, 23 New Fetter Lane, Loodon EC4A lAE

LPL-GU Guildford ATE, Leapale Road, Guildford, Surrey GU14BD

LRD-PR Guild Centre, Lords Waik, Preston, Lancashire PRl 1RA

LRL-HA Harrow TE, The Laurels, 54 Harrow View, Harrow, Middlesex HAl 1RF

LTH-EC Lintas House, 15-19 New Fetter Lane, Loodon EC4P 4EU

LTH-SE 9 Leathermarket Street, Loodon SEl 3HN

LTT-CT Liffkebourne TEC, Liffdebourne Road, Canterbury, Kent CTl lTN

LVE-EN Lea Valley Telephooe Echange, Britannia Road, Lea Valley, Waitham Cross, Hertfordshire EN8 7NR

LVR-AL St Albans TE, Liverpool Road, St Aibans, Hertfordshire ALl 3UL

LVR -SE Walworth TE, Liverpool Grore, Walworth, Loodon SE17 2HH

LYM-NW 27 Lymington Road, West Hampstead, Loodon NW6 lHZ

LYN-SE Bermondsey TE, Lynton Road, Bermondsey, London SE1 SRN

MAL-KT Malden TE, Coombe Road, Malden, Surrey KT3 4QN

MAN -MK The Mansion, Bletchley Park,, Milton Keynes, Buckinghamshire MK3 6EA

MAY-SW Mayfair Works, Opposite Arch 11 Off Miles St, Loodon SW8 2LR

MAY-W1 Mayfair TE, 41 Farm Street, London W1X 8HB

MDL-HR Madley Communication Centre, Street House Farm, Madley, Hereford Worcester HR2 9NH

MDV-W9 Maida Vaie TE, 136-138 Maida Vale, Loodon W9 lQD

MIL-IG Mill House, 11 Ilford Hill, Ilford, Essex IGl 2BZ

MIL-NW Mill Hill TE, 81-83 The Broadway, Loodon NW7 3BU

MLB-SM Wallington TE, Melbourne Road, Wallington, Surrey SM6 8SE

MLC-SE Milcote House, 1-7 Library Street, London SEl ORN

MLL-SE Chelsea TE, 19 Mallord Street, London SE3 6AP

MLT-N1 West Green TSVC, Milton Road, West Green Road, London N15 8DS

MNC-M2 Mancos House, 1 Crewe Road, Wythenshawe, Greater Manchester M23 9BE

MND-SE Central Warehouse, Mandela Way, Bricklayers Arms, London SEl 5SS

MNR-N7 ManorGardens, 10-18 Manor Gardens, London N7 6JY

MNS-RG Reading ATE, 41 Minster Street, Reading, Berkshire RG1 2JE

MON-EC Mondial House, 994 Upper Thames Street, London EC4R 3UB

MOR-N2 Mooreham House, 3-5 Bounds Green Road, Wood Green, Loodon N22 4HE

MPL-W1 9-18 Magpie Place, London WlP SFX

MRC-BS Mercury House, Bond Street, Bristol, Avon BSl 3TD

MRD-CR Mitcharn TSVC, 145 Morden Road, Mitcham, Surrey CR4 4DG

MRL-CR Southern London District Warehouse, Marlowe Way, Beddington Farm Road, Croydon, Surrey CR9 4QN

MRL-SE Merlewood House, 20 Well Hall Road, Eltham, London SE9 6SF

MRS-HA Old Pinner TE (Pinner B), Marsh Road, Pinner, Middlesex HA5 SNW

MRT-NW Merit House, The Hyde, Edgware Road, Colindaie, London NW9 SBB

MSC-W2 Bayswater TE, Moscow Road, Bayswater, London W2 4LH

MSM-EC Museum House, 174-176 Aldersgate Street, London EClA 4HN

MTC-CR Mitcham TE, 267 London Road, Mitcham, Surrey CR4 3UA

MTC-SW Streatham TSVC, 55-57 Mitcham Lane, Streatham, London SW16 6NQ

MZH-SE Greenwich DAC, 14 Maze Hill Road, Greenwich, London SE10 9XF

NSR-SE Southwark TE, 5 Nebraska Street, Great Dover Street, Southwark, London SEl 4LT

NET-LS Netel House, 6 Grace Street, Leeds, West Yorkshire LSl 1 EA

NET-NW Network House, 1 Eversholt Street, London NWl 2DN

NEW-EN New River House, Southury Rnad, Enfield, Middlessx ENl iAS

NRH-RM Hornchurch TSVC, 108a North Street, Hornchurch, Essex RMll lSU

NRT-CT Northgate House, ll5-120 Northgate, Canterbury, Kent CTl lBH

NRT-HA Northgate House, 72 Northholt Road, South Harrow, Middlesex HA2 ODW

NRT-RM Hornchurch TE, 64 North Street, Hornchurch, Essex RMll lSS

NRT-WC Bloornsbury AMC, 5 North Crescent, Chenies Street, Bloomsbury, London WClE 7ES

NSH-SN North Star House, North Star Avenue, Swindon, Wiltshire SN2 lBS

NST-HP Aylesbury ATE, New Street, Aylesbury, Buckingharmshire HP20 2N N

NTH-SE Woolwich TSVC, 7 Nathan Way, Woolwich, London SE28 OAU

NTT-Wl Marylehone ATE, 11 Nottingham place, Marylebone, London WlM 3FL

NWD-HA Northwood TE, Dene Road, Northwood, Hertfordshire HA6 2AB

NWH-HP Network House, Brindley Way, Doolittle Meadows, Aspley, Hemel Hempstead, Hertfordshire HP3 9RR

NWO-WC Commonwealth House, 1-19 New Oxford Street, London WClA lNU

NWT-AB New Telecom House, 73-77 South College Street, Aberdeen, Scotiand. ABl 2FD

OAK-IG Oakwood House, Oakwood Hill Industrial Estate, Oakwood Hiii, Loughton, Essex IG10 3TZ

OLD-EC 207 Old Street, London EClV 9PS

OLS-EC 211 Old Street, London EClV 9PS

ORP-WD Watford TSVC, Orphanage Road, Watford, Hertfordshire WDl 1PW

OXF-UR Denham ATE, Oxford Road, Uxbridge, Middlesex UB9 9DP

PET-CO St Peters House, 22 St peters Street, Colchester, Essex COl lET

PFH-EC Priory Fields House, 120 Aldersgate Street, London EClA 4JQ

PLS-EC Engineering Training Centre, 69-77 Paul Street, London EC2A 7LX

PND-CF The Coryton Building, 25 Pendwyallt Road, Coryton, Cardiff South Glamogan, Wales. CF4 7YR

PNT-Nl 91-99 Pentonvilie Road, London Nl 9LZ

PNX-MK Phoenix House, Central Piaza, 202 Eldergate North, Milton Keynes, Buckinghamshire MK9

POR-IP Telephone Exchange, Portman Road, Ipswich, Sufolk IPl 2AU

PPL-TW Ashford TSVC, Shed 3b, Popular Road, Asmbrd, Middlessex TW15 lYF

PRC-CF Coryton DEO, 29A Pendwyaiit Road, Coryton, Cardiff, South Glamorgan, Wales CF4 7XS

PRC-WC Procter House, 100-110 High Holhorn, London WClV 6LD

PRD-W2 Paddington TSVC, 12 Praed Street, Paddington, London W2 lNH

PRG-SW Parsons Green TE, 30-36 Peterborough Road, London SW6 3BN

PRK-IG Ilford TSVC, Perkins Road, Barkingside, Ilford, Essex lG2 7NQ

PRK-SE Gipsy Hill TE, 20-26 Parkhall Road, Gipsy Hill London SE21 8DW

PRK-WC Parker Tower, 43-49 Parker Street, London WC2B SPS

PRN-WC Princess Court, 8-18 Wild Street, Drury Lane, London WC2B 4DL

PRR-DN Doncaster TE, 24 Priory Place, Doncaster, South Yorkshire DNl LAA

PRR-El London Teleport, Pier Road, North Woolwich, London E16 2JJ

PRT-M0 1 Portland Street, Manchester, Greater Manchester M60 lHR

PRT-W1 WED Training Centre, 13A Portobello Road, London W11 3DA

PTR -GU Petersfield ATE, Charles Street, Petersfield, Surrey GU32 1EH

PTY-SW Albany House, 94-96 Petty France, London SWlH 9EA

PUR-CR Purley TE, 88 Brighton Road, Purley, Surrey CR2 4YD

PUT-SW Putney TE, Montserrat Road, London SW15 2LB

ONC-BS Queen Charlotte House, 53/55 Queen Charlotte Street, Bristol, Avon BS1 lBA

ONS-W5 North Ealing TSVC, 96 Queens Drive, Ealing, Londnn W5 3HY

OYH-El Quay House, Admirals Way, isle of Dogs, London E14 9XG

RBN-HA South Harrow TE, Northolt Road, South Harrow, Middlesex HA2 OBA

RCH-OL Rochdale Computer Centre, Townhead, Pitt Street, Rochdale, Greater Manchester OL12 0UW

RCH-WC Colquhoun House, 5 Richbell Piace, London WClN 3LA

RCK-Sl 220 Rockingham Street, Sheffield, South Yorkshire S1 3PL

RCS-AL Record Centre Senices, Riverside Lndustrial Estate, Lowbell Lane, London Colney, Hertfordshire AL1 7AY

RDG-E4 Chingford OAC, 145 The Ridgeway, Chingford, London E4 6QX

RDR-RM Dagenham TE, Reede Road, Dagenham, Essex RM10 8DR

RGN-CB Cambridge TE, 1 Regent Street, Cambridge, Cambridgeshire CBI IBA

RGN-SW 90-100 Regency Street, London SWIP 4AW

RLS-WC Churchill House, 35 Red Lion Square, London WCIR 4SG

ROD-El Rodwell House, 100 Middlesex Street, London El 7ilD

ROF-TN Rotherfield Exchange, New Road, Rotherfield, Crowborough, Sussex TN6 3JR

ROR-SW 17-19 Rochester Row, Victoria, London SWlP lLA

RSK -SE Ruskin House, 185 Shakespeare Road, Herne Hill London SE24 0PZ

RSL-HA Ruislip TE, High Street, Ruislip, Middlesex HA4 7BJ

RSL-UB Greenford TE, Rulslip Road, Northolt, Greenford, Middlesex UB5 6HE

RSS-WC Covent Garden ATE, 24-28 Russell Street, Covent Garden, London WC2B SHL

RVR-N2 River Park House, 225 High Road, Wood Green, London N22 4LN

RVR-SE Riverside House, 2a Southwark Bridge Road, London SE1 9BA

RWN-SO Rownhams TR, Rownhams Lane, Rownhams, Southampton, Hampshire SO1 8AP

RYL-CR Ryland House, Church Road, Croydon, Surrey CR9 lPA

RYL-E1 Wapping TE, Royal Mint Street, Wapping, London E1 8LQ

SCT-SP Salisbury TE, Scotts Lane, Salishury, Wiltshire SP1 3TW

SDC-DA Sidcup TE, 4-6 Station Rnad, Sidcup, Kent DA15 7ED

SDD-SW Sloane Square TE, Sedding Street, Sloane Square, London SWlX 9DF

SEN-TW Osterley Computer Centre, Unit 1, Centaurs Business Park, Syon Lane, Osterley, Middlesex TW7 SQD

SGB-HA Stanmore Government Buildung, London Road, Stanmore, Middlesex HA7 4BT

SHA-WC 177-199 Shaftesbury Avenue, London WC2H 8BA

SHF-WC 125 Shatteshury Avenue, London WC2H 8BE

SHN -UK Shenley Church End ATE, Wolfscote Lane, Emerson Valley, Milton Keynes, Buckinghamshire MK5 6A

SHR-El Shoreditch High Street OAC, 74 Shoredltch High Street, London E1 6JN

SHT-SE Kidbrook TE, 401 Shooters Hill Road, Kidbrook, London SE18 4LH

SKY-TW Skyport House, IA Bath Road, Heathrow, Hounslow, Middlesex TW6 2HS

SLV-Nl Edmonton TE, 56-62 Silver Street, Edmonton, London N18 lQT

SNB-TW Sunbury on Tharnes TE, Hanworth Road, Sunbury on Thames, Middlesex TW13 SAF

SND CR Sanderstead TE, Church Way, Sanderstead, Surrey CR2 OYE

SND-SM Sandiford TSC, 14 Sandiford Road, Sutton, Surrey SM11 BA

SPD-OX Oxford TE, 35 Speedwell Street,, Oxford, Oxfordshire OX11 RH

SPW-NW 22/24 St Pancras Way, London NW1 OQG

SST-RM Romford South ATE, 192 South Street, Romford, Essex RM1 lHL

STA-AL St Albans Computer Centre, 156 St Albans Road, Sandridge Street, St Albans, Hertfordshire AL4 9NH

STA-BN Eastbourne Neville Exchange, 31 St Annes Road, Eastbourne, West Sussex BN21 2DD

STA-EC St Alpbage House, 2 Fore Street, London EC2Y 6XA

STA-TW Staines CSC, Fairfield Avenue, Staines, Middlesex TW18 4AB

STA-W7 Hanwell ATE, Station Road, London W7 3JF

STB-EC St Botolph House, 138 Hounditch, London EC3 7ND

STD-N1 Studd Street, London N1 OQL

STF-CR Croydon TSVC, Stafford Road, Croydon, Surrey CR9 SQU

STG-LE 1 St Georges Way, Leicester, Leicestershire LEI IBA

STG-WC St Giles House, I Drury Lane, London WC2V SRS

STH-DT Dorchester TE, South Walks, Dorchester, Doret DTI I EA

STH-RM Romford GSC, 192 South Street, Romford, Essex RMI ITR

STJ-LS St Joseph's Well Hanover Walk, Leeds, West Yorkshire LS3 IAB

STL-N1 Edmonton ATE/AMC, Stirling Way, Edmonton, London N18 IQII

STM-PO Ryde ATE, St James Street, Ryde, Isle of Wight PO33 2N H

STM-SE New Cross TE, 24 St Mary's Road, New Cross, London SEI5 2DP

STM-W2 Paddington TE, 75 77 St Michaels Street, Paddington, London W2 IQS

STM-W5 Ealing TE, St Marys, The Green, Ealing, London W5 SEI

STN-HA Stanmore TE, Elm Park, Stanmore, Middlesex HA7 4AX

STN-ME Stoneborough House, King Street, Maidstone, Kent MEI5 6AW

STN-TW Staines TE, Tothill Street, Staines, Middlesex TW8 4PZ

STP-NW Cricklewood TSVC, Staples Corner, North Circular Road, Cricklewood, London NW2 ILY

STR-CO Stuart House, St Peters Street, Colchester, Essex COI IHU

STR-KT Ashstead TE, 13 The Street, Ashstead, Surrey KT21 2AF

STT-RH Merstham TE, Station Road North, Merstham, RedhilI Surrey RH1 3ED

STT-W4 Chiswick DQ, 14 Sutton Court Road, Chiswick, London W4 4NQ

STW-SW Nine Elms TE, 180 Stewarts Road, Battersea, London SW8 4UQ

SVH-IP St Vincent House, Cutler Street, Ipswich, Suffolk IP1 IUX

SWN-NE Swan House, 157 Pilgrim Street, Newcastle-Upon-Tyne, Tyne and Wear NEl IBA

SWN-UB West Drayton TE, Swan Road, West Drayton, Middlesex UB7 7BS

TAV-KT Taverner House, 101 Birkenhead Avenue, Kingston-Upon-Thames, Surrey ICI 2 6RP

TEC-S6 Birmingham TEC, 41 Essex Street, Birmingham, West Midlands B5 4TS

THM-DA Crayford Distribution Centre, Thames Road, Crayford, lient DAl 4QX

THO-CR Thornton Heath TE, 147 Brigstock Road, Thorton Heath, Surrey CR4 7XE

THP-PR Telephone House, 170-175 Moor Lane, Preston, Lancashire PRl I BA

TLC-HH Telecom House, 35 Holdenhurst Road, Bournemouth, Dorset BH8 8EI

TLC-SN Telecom House, 125-135 Preston Road, Brighton, East Sussex BN1 6BG

TLC-GU Telecommunications House, Alexandra Road, Aldershot, Hampshire GUI I 31A

TLC-M6 Telecom House, 91 London Road, Manchester, Greater Manchester M60 IHQ

TLC-MK Telecom House, 25-27 St Johns Street, Bedford, Bedfordshire MK42 OBA

TLC-N8 Telecom House, 71 Crouch End Hill, Crouch End, London N8 8BA

TLC-OX Telecom House, 16 Paradise Street, Oxford, Oxfordshire OX1 lBA

TLC-RG Telecom House, 49 Friar Street, Reading, Berkshire RGl lBA

TLC-WR Telecom House, Charles Street, Worcester ,Hereford & Worcester WR12BE

TLH-BR Telephone House, 25-27 Elmfield Road, Bromley, Kent BRl lLT

TLP-BH Telephone House, 18 Christchurch Road, Bournemouth Dorset BHl 3BA

TLP-CH Telephone House, Tower Wharf Chester, Cheshire C Hl 1 BA

TLP-CT Telephone House, Rheims Way, Canterbury, Kent CTl 3BA

TLP-E7 Telephone House, 4-20 Woodgrange Road, Forest Gate, London E7 OBA

TLP-EC Telephone House, Temple Avenue, London EC4Y OHL

TLP-EH Telephone House, 357 Gorgie Road, Edinburgh, Scotland. EHll 2RP

TLP-IP Telephone House, 153 Princes Street, Ipswich, Suffolk IPl lQB

TLP-LS Telephone House, 35 Lisbon Street, Leeds, West Yorkshire LS1 1 BA

TLP-NR Telephone House, 41-45 St Giles Street, Norwich, Norfolk NR2 lBB

TLP-NW Telephone House, 1-15 Shoot-Up Hill Kilburn, London NW2 3BA

TLP-PE Telephone House, Wentworth Street, Peterborough, Cambridgeshlre PE11 BA

TLP-PO Telephooe House, 64-68 Elm Grove, Southsea, Hampshire P05 lBA

TLP-Sl Telephooe House, Charter Row, Shefield, South Yorkshire S1 lBA

TLP-SE Telephone House, 10-18, London Bridge Street, London SEI 9SH

TLP-SO Telephone House, 70-75 High Street, Southampton, Hampshire SO9 lBB

TLP-SS Telephone House, 45 Victoria Avenue, Southend-on Sea, Essex SS2 6BA

TLP-TN Telephone House, Church Road, Tunbridge Wells, Kent TN 11 BA

TLS-SW Tulse Hill ATE, 64 New Park Road, London SW2

TNT-EC Tenter House, 45 Moorfields, London EC2Y 9TH

TSC-NE Hadrian Trunk Switching Centre, 5th Floor, Melhourne Street, Newcasde-Upon-Tyne, Tyne and Wear N El 2JQ

TUF-Nl Tufnell Park Complex, Unlt D, Bush Industriai Estate, Station Road, London N19 SUW

TWC -TW Isleworth TE, Twickenham Road, Isleworth, Middlesex TW7 6AS

TWN-NW Primrose Hill TE, 41-43 Townsend Road, Primrose Hill London NW8 6LL

UPH-N4 Upper Holloway TE, 15 Pine Grove, Lonon N3 3LL

UPP-SW Mortlake TE, 166 Upper Richmond Road West, Mortlake, London SW14 8AW

VXH-SE Vauxhall TE, 100 Kennington Park, Vauxhall London SE11 4EF

WBL-HA North Wembley TE, Carlton Avenue East, Preston Road, Wembley, Mlddlesex HA9 8LU

WDC-PO Waterlooville Data Centre, 1 Relay Road, Waterlooville, Hampshire P07 7AX

WDS-Ll Royal ATE, 100 Wood Street, LiverpooL Merseyslde Ll 4DA

WEL-AL Welwyn Garden TE, Wigmores North, Welwyn Garden Clty, Hertfordshue AL8 6PH

WEL-CO Wellington House, 90-92 Butt Road, Colchester, Essex C03 3DQ

WFD-WD Watford TE, 57-71 Exchange Road, Watford, Hertfordshire WD11 BB

WFT-IG Woodford TE, 4, Snakes Lane West, Woodford Green, Essex IG8 OBS

WHT-SY Whittington House, Park Hall, Oswestry, Shropshire SY11 4TB

WLD-BR Bromley TSVC, 39 Woldham Road, Bromley, Kent BRl 9LA

WLD-SE Forest Hill TE, 3 Waldram Park Road, Forest Hill London SE23 2PP

WLH-WC Wellington House, 6-9 Upper St Martin's Lane, London WC2H 9DL

WLL-KT Kingston TSVC, Willow Road, Kingston, New Malden, Surrey lT3 3RD

WLL-Nl West Green TSVC, Willow Walk, West Green Road, London N15 3DJ

WLL-SL Slough ATE, 100 Wellington Street, Slough, Berkshire SLl lTR

WLP-W5 Walpole House, 18-20 Bond Street, Ealing, London W5 SM

WLS-El Walthamstow TE, 317 Hoe Str eet, London E17 9 B E

WLT-KT Walton TE, New Zealand Avenue, Walton-on-Thames, Surrey KT2 lPR

WLT-NG Walton House, 34 StJames Street, Nottingham, Nottinghamshire NGl lBA

WNH-EC Williams National House, 11-13 Holhorn Viaduct, London EClA 2AT

WNT-RM Dagenham TSVC, Wantz Road,, Dagenham, Essex RM10 3PS

WOL-SE Woolwich TE, 28 Spray Street, London SE18 6AL

WOR-KT Worcester Park TE, Rear of Post Otice, Green Land, Worcester Park, Surrey KT4 8AB

WRC-W1 West Kensington TE/TSVC/MTW, 213-215 Warwick Road, West Kensington, London W148BQ

WRP-SW Telecom House, 21-33 Worple Road, Wimbledon, London SWl9 4BA

WRR-SW Wandsworth TSVC, 65 Weir Road, Wimbledon, London SWI9 8UG

WRW-Wl Warwick House, 8-13 Great Poultney Street, London Wl R 3DG

WST-BH West Howe TEC, 891 Ringwood Road, West Howe, Bournemouth, Dorset BHll 8LS

WST-G2 Westergate, 11 Hope Street, Glasgow, Scotland. G2 6AB

WST-SL Maidenhead ATE, West Street, Maidenhead, Berkshire SL6 I RG

WST-SW Westminster TE, la Broadway, London SWlH OAY

WST-W5 Westel House, 32-38 Uxbridge Road, London W5 2BA

WTH-BN Withdean Grange, London Road, Brighton, East Sussex BNl 6YQ

WTH-WC Weston House, 246 High Holborn, London WClV 7DQ

WVR-W1 Waverley House, 7-12 Noel Street, London WlV 3PB

WXB-NW Harlesden TSVC, Waxlow Road, Harlesden, London NW10 7NU

WYB-KT Weybridge TE, Heath Road, Weybridge, Surrey KT13 8TA

rhaines · June 17, 2003

Well I was close...

"AUTO is short for automatic. Almon Strowger, an undertaker from Kansas (USA), invented a basic electromechanical exchange for automatically switching telephone calls. He did this because he thought that his rivals wife, who worked on the towns manual telephone exchange, was diverting his calls to her husband. Strowgers system automatically routed calls without the assistance of an operator. The telephone instrument has to have a dial and his system known as `Strowger' was still used in UK public exchanges until a few years ago.

Strowger systems are not the only type of automatic exchange in existence. Many others were made based on a variety of components ranging from relays to wafer switches.

The BPO introduced Crossbar and Electronic exchanges in the late 1960's - early 1970's and these were superseded by System X and System Y (both digital).

These and other public exchange systems are too complex a subject to describe in this document and you are advised to read Telephony by Atkinson for a complete technical description"

Fidgits · June 17, 2003

Monster-Mat · June 17, 2003

How the Telephone Works

When a person speaks into a telephone, the sound waves created by his voice enter the mouthpiece. An electric current carries the sound to the telephone of the person he is talking to. A telephone has two main parts: (1) the transmitter and (2) the receiver.

The Transmitter of a telephone serves as a sensitive "electric ear." It lies behind the mouthpiece of the phone. Like the human ear, the transmitter has an 14 eardrum." The eardrum of the telephone is a thin, round metal disk called a diaphragm. When a person talks into the telephone, the sound waves strike the diaphragm and make it vibrate. The diaphragm vibrates at various speeds, depending on the variations in air pressure caused by the varying tones of the speaker's voice.

Behind the diaphragm lies a small cup filled with tiny grains of carbon. The diaphragm presses against these carbon grains. Low voltage electric current travels through the grains. This current comes from batteries at the telephone company. The pressure on the carbon grains varies as sound waves make the diaphragm vibrate. A loud sound causes the sound waves to push hard on the diaphragm. In turn, the diaphragm presses the grains tightly together. This action makes it easier for the electric current to travel through, and a large amount of electricity flows through the grains. When the sound is soft, the sound waves push lightly on the diaphragm. In turn, the diaphragm puts only a light pressure on the carbon grains. The grains are pressed together loosely. This makes it harder for the electric current to pass through them, and less current flows through the grains.

Thus, the pattern of the sound waves determines the pressure on the diaphragm. This pressure, in turn, regulates the pressure on the carbon grains. The crowded or loose grains cause the electric current to become stronger or weaker. The current copies the pattern of the sound waves and travels over a telephone wire to the receiver of another telephone.

The Receiver serves as an "electric mouth." Like a human voice, it has "vocal cords." The vocal cords of the receiver are a diaphragm. Two magnets located at the edge of the diaphragm cause it to vibrate. One of the magnets is a permanent magnet that constantly holds the diaphragm close to it. The other magnet is an electromagnet. It consists of a piece of iron with a coil of wire wound around it. When an electric current passes through the coil, the iron core becomes magnetized. The diaphragm is pulled toward the iron core and away from the permanent magnet. The pull of the electromagnet varies between strong and weak, depending on the variations in the current. Thus, the electromagnet controls the vibrations of the diaphragm in the receiver.

The electric current passing through the electromagnet becomes stronger or weaker according to the loud or soft sounds. This action causes the diaphragm to vibrate according to the speaker's speech pattern. As the diaphragm moves in and out, it pulls and pushes the air in front of it. The pressure on the air sets up sound waves that are the same as the ones sent into the transmitter. The sound waves strike the ear of the listener and he hears the words of the speaker.