The website has become a fascinating mine of information on the U.K. Communications Networks, the U.K.W.M.O. and Royal Observer Corp, thanks entirely to the wonderful feedback of information and photographs from visitors since its inception in 2001. I wish to express my thanks to all those who have helped over the years and encourage others to share anything they know as this might be the little missing piece of the jigsaw needed to complete the full picture.
24/09/2018 Added page 'All Underground Network'
23/09/2018 Website layout completely revised
04/06/2018 Improved images of Maroon Trainer and PDRM82
27/04/2018 Added 4 Images to S+DX gallery. 2 Testers to WB400 page
29/01/2018 Proposed RN5 replacement Last Ditch Network HF Radio added to LDN
28/12/2017 4 new thermostat photos from Paul Lawrence to Power Siren page. Updated RBDxxx routing codes text
11/12/2017 WB1400 Pt1 - Added topic East Kilbride CCA receiver points.
28/11/2017 EMSS - Rewrite of page thanks to Dave McKay G1JWG finding a EMSS network diagram in National Archives.
05/11/2017 Added 2 photos from Trevor Bishenden, 1 from Roy Coulter to Siren page.
05/10/2017 Added BT Heritage Film from 1982, Wire Broadcast Warning Systems for the Future.
25/09/2017 Added Switch Panel Type III and 8 new photos from Paul Lawrence: SECOMAK siren.
09/09/2017 Added Switch Panel in situ (tnx Richard Bowden).
03/07/2017 Added 6 photos of the construction of Portsdown PR1.
13/05/2017 Six additional photos of control unit to System-E gallery from the BT Archives.
12/05/2017 From BT Archives: WB200 Carrier Control Point, Unit Sig. WB600 added.
29/04/2017 Added 12 Images to the galleries from BT Archives.
2016 Seven Updates
2015 Nine Updates
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Many of us signed the Official Secrets Act, this protected information for 30 years, so anything pre-1987 is now open. The National Archives in Kew have files previously classified Secret open to public inspection which form the basis for a number of pages on this website. The Freedom of Information Act, has opened younger files too.
A lot more has been discovered in the National Archives But this topic needs a little more exploring. Clear photographs of the jack fields on any remaining basement switchboards or a list of their routes would be equally helpful. The incoming jacks usually repeat themselves every four or six appearances, so its not necessary to photograph the whole of the switchboard.
Have you worked on a transistorised 24-ch carrier system, where certain pairs were intercepted and amplified in manholes while the remaining pairs went inside the TRS. Some parts were upgraded to Digital with the EDL8.
GPO / BT may not recognise this codeword for the network explained in the topic National Communications / All Underground I suspect there is more to the network than shown on the map on that page, perhaps a missing leg to Shrewsbury - any ideas?
Do you remember any Carrier Control Area three digit numbers, as I'm trying ascertain the numbering scheme. A few are listed in topic National Warning Scheme / Development of
The A886's for WB1400 have PW numbers 103xxx, where xxx is the carrier area number, I am trying to find.
Diagram titles suggest there may have been WB400 CCP's without HANDEL phones, where were they and how did they receive the national warning message if not connected to the speaking clock ?
Colour photos of WB600 receiver external or internal sub boards to replace the B/W from BT Archives.
Any ROC Post Radios Group frequencies, using the ATE Countryman radio, in high-band before the move to 80 MHz.
Any pre-RN1 / RN2 era, VHF links for Home Defence / UKWMO, those shown as "Route Unknown" on Page: Core Communications Network / First Generation, expand the route diagram found toward bottom of page titled "UKWMO VHF Link Details and Frequencies". I have been supplied with two sets of personal notes / diagrams drawn by DTELs staff used to build this diagram. Do you have anything similar?
Any sketches or lists of links (however small an area covered) of the UHF home defence network between Regional Government HQ's and local authority emergency centres. Era prior to the introduction of RN1, possible using Plessey valve operated multiplex - ATE800 / 900
Already showing RN1 network diagram but have next to nothing for RN2, so any tiny scrap of information in or around one county or RGHQ would aid understanding immensely. Aerial direction diagrams for masts would be useful too. Do you have any examples of the actual GHz frequencies of RN1 links to determine the channel spacing.
Still more to find out. Do you know of a location actually issued with the SSB125 radios. We now know the bands involved but not the actual Regional Frequencies used for training? A recently opened PRO file mentions RN5 as a replacement for the SSB125 radios. Did this ever roll out ?
There is a great shortage of information about all UKWMO communications in Scotland so even the smallest scrap would be helpful.
ROC Standard Operation Procedures (SOP) Annex G shows the English / Welsh / NI 80 MHz ROC Post frequencies for RN4, but the Scottish section is marked 'Details not Available'. I am still missing those 80MHz frequencies for Ayr and Edinburgh Groups. We have none of the five Scottish groups frequencies used prior to the introduction of RN4, at a time when England and Wales were on VHF highband. Did they even have radios in posts before RN4, as Belfast Group didn't.
UHF / Microwave links equivalent to the RN1 and RN2 in England & Wales, are any details of the network available.
I became interested in the UK Civil Defence for the Cold War, as a result of working as a engineer for 'Post Office Telephones' later privatised and renamed 'British Telecom'. Between 1978 and 1981 I maintained the early warning equipment and visited ROC posts in part of North Northamptonshire and South Leicestershire. At the time I never disclosed this information even to my closest friends. Now twenty-five years have passed since the Cold War ended the Internet provides a good medium to disseminate the details of these defunct systems.
I am always pleased to hear from visitors to the website whether or not you have anything to add to the topics discussed.
Contact Details for Steve Scanlon