UK Vintage Radio Repair and Restoration Powered By Google Custom Search Vintage Radio Service Data

Go Back   UK Vintage Radio Repair and Restoration Discussion Forum > Specific Vintage Equipment > Vintage Telephony and Telecomms

Notices

Vintage Telephony and Telecomms Vintage Telephones, Telephony and Telecomms Equipment

Closed Thread
 
Thread Tools
Old 9th Sep 2018, 12:36 pm   #21
Oldcodger
Octode
 
Join Date: Oct 2014
Location: West Midlands, UK.
Posts: 1,134
Default Re: Dialling before STD

ref #16 - thanks for that Pellseinydd. I knew of the existence of the operator's trunk network. We had access to it at one TRS I worked at and it very useful when systems went down and the STD network got congested. Sometimes knowing the routing of a group could help locate the source of the problem and get a faullt no.
Oldcodger is offline  
Old 16th Sep 2018, 12:50 am   #22
midshires
Triode
 
Join Date: May 2007
Location: Northampton, UK.
Posts: 32
Default Re: Dialling before STD

Actually VIF stood for Visible Index File. There's one for sale on eBay last week (https://www.ebay.co.uk/itm/vintage-G...-/263927216697) but it was empty, missing all those tasty trunk dialling codes!.
midshires is offline  
Old 16th Sep 2018, 9:15 pm   #23
Scott37
Triode
 
Join Date: Aug 2018
Location: Glasgow, Scotland, UK.
Posts: 40
Default Re: Dialling before STD

Just as I thought I understood this, I visited the Postal Museum and saw a few call boxes. I noticed this list of dialling codes. It appears they have 'redacted' the name of the local exchange though I assume it was to the north of London. As far as I can see, for a local number you dialled the number only (no code). How would the exchange know this was a local number? Nowadays all codes start with '0'. In earlier days of all-figure numbers I think they were '0', '8' or '9'. How did this previous system work? Did they have to find all the codes and exclude local numbers starting with the same digits, or did they take the first digit of the local numbers and make sure this was not used as the start of any code? How did this fit in with the idea of having meaningful codes?
Attached Thumbnails
Click image for larger version

Name:	IMG_3959.jpg
Views:	36
Size:	48.5 KB
ID:	169424  

Last edited by Scott37; 16th Sep 2018 at 9:36 pm. Reason: Comprehensibility
Scott37 is offline  
Old 17th Sep 2018, 11:48 am   #24
Pellseinydd
Hexode
 
Join Date: Jul 2007
Location: Flintshire, UK.
Posts: 376
Default Re: Dialling before STD

Within the London (or any other) Director area, you dialled the first three letters of the exchange name followed by the four numeric digits - effectively it was a seven digit number with the first three letters being the routing code to the required exchange. (Don't worry about how it was achieved). Hence you still dialled the first three letters to indicate it was an 'own exchange' call. To reach exchanges outside the Director area but within the local call charge area, you dialled a local code of letters/digits to reach the required exchange. The length of the local codes varied such that the total number of digits required was seven (same length as the 'Director' exchange numbers'. Outside the Director areas, you just dialled the number on your own exchange (or another exchange in a 'Linked Numbering Scheme' where the first digit/s indicate the required exchange) . For other local exchanges you would dial between one and seven digits to reach the other exchange in the local call area. With the coming of STD, the number of digits in the code for a local call was reduced. STD codes could be used for a local call and charged at the local rate as is done these days. To think it is nearly a quarter of a century since local dialling codes ended. However we still have them 'preserved' on CNet, our replica of the old GPO UK phone network as it was back in the days before the coming of 'Linked Numbering Schemes. I can reach 'Chester' numbers by dialling the old local code 91 or I can dial 0244 - makes no different except that with the STD code can't dial Chester numbers beginning with a 9 or 0 after the 0244 - just as it was in the good old days. Interesting that we now have subs numbers beginning with 9 so that rule has obviously gone!
Pellseinydd is offline  
Old 17th Sep 2018, 12:08 pm   #25
Pellseinydd
Hexode
 
Join Date: Jul 2007
Location: Flintshire, UK.
Posts: 376
Default Re: Dialling before STD

Quote:
Originally Posted by Scott37 View Post
Just as I thought I understood this, I visited the Postal Museum and saw a few call boxes. I noticed this list of dialling codes. It appears they have 'redacted' the name of the local exchange though I assume it was to the north of London. As far as I can see, for a local number you dialled the number only (no code). How would the exchange know this was a local number? Nowadays all codes start with '0'. In earlier days of all-figure numbers I think they were '0', '8' or '9'. How did this previous system work? Did they have to find all the codes and exclude local numbers starting with the same digits, or did they take the first digit of the local numbers and make sure this was not used as the start of any code? How did this fit in with the idea of having meaningful codes?
Incidentally, the notice is a reproduction that someone has made - As it refers to dialling from exchanges in the London Director Area , they all just dialled the seven digit number or the listed codes and numbers - no need to define the exchange. But at the bottom of the notice, it indicates that the notice was for 'Non-Director exchanges and UAXs' !! See a attached similar reproduction notice which has the top few lines correctly worded but still with the 'ND & UAXs' at the bottom.
Attached Thumbnails
Click image for larger version

Name:	CO22LondonDA.jpg
Views:	24
Size:	78.7 KB
ID:	169450  
Pellseinydd is offline  
Old 17th Sep 2018, 1:09 pm   #26
Scott37
Triode
 
Join Date: Aug 2018
Location: Glasgow, Scotland, UK.
Posts: 40
Default Re: Dialling before STD

Thanks for the replies. I'm still a bit puzzled. I assumed the notice was for a non-Director exchange, with the name of the exchange blanked out. Should the missing space read 'London'? This still leaves the question of what would happen in a non-Director exchange. How would the system know that a local number was indeed a local number and not one of the local codes; and that a code was not the start of a local number? Was there one reserved digit for the local numbers?
Scott37 is offline  
Old 17th Sep 2018, 4:16 pm   #27
OscarFoxtrot
Heptode
 
OscarFoxtrot's Avatar
 
Join Date: Apr 2011
Location: Edinburgh, UK.
Posts: 603
Default Re: Dialling before STD

Yes.

Either there was a Linked Numbering Scheme, or there were local codes. In a Linked Numbering Scheme the parent exchange would have numbers starting eg 7xxxx. Satellite exchanges would have numbers starting 81xxxx, 82xxxx, 83xxxx etc. Dialling from a satellite exchange the exchange would recognise what was an own-exchange call and drop the first two digits, and calls for another satellite exchange would route to the parent exchange by the 8, then the outgoing junction circuit 1, 2, 3 etc.

Subscribers on the parent exchange had direct access to the junctions by dialling 81, 82, 83 etc.

With exchanges not in Linked Numbering Scheme, there were local codes, usually starting 9 (or sometimes 8). Eg 9 for the parent exchange then 8081 for the Speaking Clock. This lead to local codes like 981 from B to A, but A to B would be 81. C to B might be 9812 etc. Basically with local codes you had to dial the digits that controlled the actual routing of the call over the junction circuits. In the Director system the director part of the exchange took the exchange code (ABBey etc) and translated it into the digits required to route the call even if that was through two or three tandem (intermediate) exhcanges).
OscarFoxtrot is offline  
Old 17th Sep 2018, 4:49 pm   #28
Pellseinydd
Hexode
 
Join Date: Jul 2007
Location: Flintshire, UK.
Posts: 376
Default Re: Dialling before STD

Quote:
Originally Posted by Scott37 View Post
Thanks for the replies. I'm still a bit puzzled. I assumed the notice was for a non-Director exchange, with the name of the exchange blanked out. Should the missing space read 'London'? This still leaves the question of what would happen in a non-Director exchange. How would the system know that a local number was indeed a local number and not one of the local codes; and that a code was not the start of a local number? Was there one reserved digit for the local numbers?
The codes on the notice that you saw were the local codes to be dialled to reach the exchanges that could be dialled and charged at the local rate (pre-STD working). The wording is for 'Non-Director' and UAXs - not a Director area. It has been reproduced to go in the Frames Notice No 30 on a small 'renters' backboard for use with an A/B box in pubs, hotels, boarding houses etc. I've attached a copy of an original notice (CO7) from a red K6 kiosk which has the correct wording in the upper part for a London Director Area exchange and in lower part how to reach the exchanges in the local area outside the London Director Area. I've also attached a copy of a notice for a 'Non-Director' exchange that acts as a 'Group Switching Centre - the 'main exchange' that acted as a 'parent' exchange for a number of smaller UAXs (Unit Automatic eXchanges). - most local cards were two digits starting initially with an '8' and when they had been exhausted aa '7'. But there were plenty of exceptions. Then I've added the dialling code cards for Aidensfield and Emmerdale - two small country exchanges (UAXs)with three digit numbers. Note how they dial a '9' to reach the parent exchange (Whitby in the case of Aidensfield and Hotten in the case of Emmerdale) then if it was another exchange a 'local' code from the GSC/parent exchange was dialled. Some small exchanges, mainly in pre-STD days, had a direct route to another local exchange using say an '8' - see the local code from Aidensfield to Ashfordly as an example. Some of these local codes survived into the days of 'STD' if the number of calls warranted it. For instance a local exchange to here (Buckley 0244 54 in STD days but 54 from Chester) had a direct local code to the nearby (2.5 miles) GSC at Mold (0352) by dialling 85. Conversely, Mold subscribers could reach Buckley by dialling 94. There are very many exceptions to the numbering but in the main in later years a smaller exchange dialled a '9' to reach its parent/Group Switching Centre. There was also 'call barring' on some routes such that a call coming into a GSC from one 'side' couldn't dial a code which took it outside the 15 mile 'local call' area. But on occasions, the strapping on the call barring was missing and it became possible to 'daisychain' dialling codes to get way outside your 'local' area. We've recreated most of this on CNet so that we can dial these old codes. Great to be able to pick an old rotary dial telephone - the likes of an old 'Bakelite' Tele 332 - and dial the digits to reach a distant telephone/recording. You need to get yourself connected to try it all out - the best way to learn.
Attached Thumbnails
Click image for larger version

Name:	CO7-London-Dir-Area-upper.jpg
Views:	15
Size:	64.6 KB
ID:	169454   Click image for larger version

Name:	CO7-London-Dir-Area-lower.jpg
Views:	15
Size:	60.8 KB
ID:	169455   Click image for larger version

Name:	CO31-Porthmadog-1956.jpg
Views:	15
Size:	31.9 KB
ID:	169456   Click image for larger version

Name:	CO22-Aidensfield-Emmerdale.jpg
Views:	14
Size:	55.2 KB
ID:	169457  
Pellseinydd is offline  
Old 17th Sep 2018, 4:58 pm   #29
Scott37
Triode
 
Join Date: Aug 2018
Location: Glasgow, Scotland, UK.
Posts: 40
Default Re: Dialling before STD

Thanks, but I think you may be referring to a later era. The list I posted shows codes which - after converting letters to numbers - start with all sorts of digits. Could it be that this list applies only to Director areas? If so, did other exchanges have lettered local codes? How did the system distinguish between code starts and number starts?
Attached Thumbnails
Click image for larger version

Name:	IMG_3959 edited.jpg
Views:	15
Size:	104.7 KB
ID:	169459  
Scott37 is offline  
Old 17th Sep 2018, 5:12 pm   #30
Pellseinydd
Hexode
 
Join Date: Jul 2007
Location: Flintshire, UK.
Posts: 376
Default Re: Dialling before STD

Quote:
Originally Posted by Scott37 View Post
Thanks, but I think you may be referring to a later era. The list I posted shows codes which - after converting letters to numbers - start with all sorts of digits. Could it be that this list applies only to Director areas? If so, did other exchanges have lettered local codes? How did the system distinguish between code starts and number starts?
Before the introduction of 'All Figure Numbering' (AFN) in the mid 1960's, the 'letters' were dialled which obviously have a numeric equivalent. Once AFN came in, the same codes were dialled but with the numeric equivalent being quoted. Thus 'UX' for Uxbridge became '89' or 'CU4' for Cuffley became '284' . However over time as the length of the numbers on these exchanges became longer, the codes would be changed by becoming shorter to keep the same seven digit long numbers.

Around that time, London had 'sectorisation' were the exchange names were done away with and the first three letters (or their numeric equivalent) replaced with a different three digits - thus WHI (944) became 930.

All helps to confuse the issue
Pellseinydd is offline  
Old 17th Sep 2018, 5:25 pm   #31
Scott37
Triode
 
Join Date: Aug 2018
Location: Glasgow, Scotland, UK.
Posts: 40
Default Re: Dialling before STD

Thanks, Pellseinydd, but I am actually more confused! (1) Leaving aside Director areas (which I think I understand thanks to your explanation), in the other areas if lettered codes were used how did the system distinguish between the numerical equivalent of the lettered code and a local number? I am sure you did not have to dial your own code at that time. (2) For London, were all exchanges sectorised or just the new ones. I lived in 274, which translates to BRIxton. I worked in 432, which translates to HEAdquarters and I'm sure I remember others that were direct equivalents. I know Glasgow is sectorised. All ours are 3xx, city centre 2xx etc. Ours used to be WEStern so clearly the numbers do not correspond to the letters any more. I hope others are as intrigued as I am.
Scott37 is offline  
Old 17th Sep 2018, 5:30 pm   #32
Pellseinydd
Hexode
 
Join Date: Jul 2007
Location: Flintshire, UK.
Posts: 376
Default Re: Dialling before STD

Quote:
Originally Posted by Scott37 View Post
Thanks, but I think you may be referring to a later era. The list I posted shows codes which - after converting letters to numbers - start with all sorts of digits. Could it be that this list applies only to Director areas? If so, did other exchanges have lettered local codes? How did the system distinguish between code starts and number starts?
The local codes from London DA would be those digits that hadn't already be used as the initial digits of exchange names (the letters were only used to make remembering numbers easier). That list that you have is purely from exchanges in the London 'Director' area. Codes between those exchanges .outside the Director area would have been quite different. Bear in mind that a 'Director' as used in a Director Area was a mechanism that translated the initially dialled digits into the actual code that was needed to be dialled through usually more than one exchange to reach the distant exchange - whether it was in the Director area or one of the local 'fringe' area exchanges.

Don't look to deeply as in later years, the local code from London DA to 'Lea Valley' exchange on the east side of London was '9' (Lea Valley had six digit numbers) but at the same time, the local code from the LDA to Walton-on-Thames on the opposite side of London was '98' or to Redhill in Surrey was '91' . It was all handled by the Director which looked up the digits dialled and translated them into the digits actually required to be sent to set the call up.
Pellseinydd is offline  
Old 17th Sep 2018, 5:43 pm   #33
Scott37
Triode
 
Join Date: Aug 2018
Location: Glasgow, Scotland, UK.
Posts: 40
Default Re: Dialling before STD

Thanks, Pellseinydd. I think our posts may have crossed. I hope I understand the situation in the Director area. My latest - and I hope final - question is what coding system was used elsewhere and how were the local numbers distinguished from the codes.
Scott37 is offline  
Old 17th Sep 2018, 9:29 pm   #34
Scott37
Triode
 
Join Date: Aug 2018
Location: Glasgow, Scotland, UK.
Posts: 40
Default Re: Dialling before STD

I think I have answered my own question now The lettered codes were only used in Director areas (where they were co-ordinated with exchange names to avoid conflicts). Outside the Director areas the codes were numerical with different starting digits to the local numbers (usually 8 or 9). I hope this is correct
Scott37 is offline  
Old 18th Sep 2018, 12:10 pm   #35
Scott37
Triode
 
Join Date: Aug 2018
Location: Glasgow, Scotland, UK.
Posts: 40
Default Re: Dialling before STD

Thanks for everyone's contributions to this thread. I feel better informed now. I see we got an encouragingly large number of views
Scott37 is offline  
Closed Thread

Thread Tools



All times are GMT +1. The time now is 11:56 am.


All information and advice on this forum is subject to the WARNING AND DISCLAIMER located at https://www.vintage-radio.net/rules.html.
Failure to heed this warning may result in death or serious injury to yourself and/or others.


Powered by vBulletin®
Copyright ©2000 - 2018, vBulletin Solutions, Inc.
Copyright ©2002 - 2018, Paul Stenning.