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No.8 - Spring 1982 Please circula te The Quarterly for BBC Engineering StaH In this edition of ENG 'NF ENHANCED CEEFAX ON AIR Page I EDITORIAL Page 2 TRANSMITIERS OPENING AND CLOSING Page 2 ELECTRONIC STILLS STORE Page 3 TV WAVEFORM ANALYSER Page 4 NEWSTUDIOS FOR BH Page 4 AUTOMATIC TESTING The BBC has made the first public Blue (RGB) samples, occupying some Page 5 broadcast of high quality still pictures 1.2 M bytes of storage space. This by means of the UK Telctext system. represents an active picture size of 702 EXTENDED PAL The broadcast high-quality pictures and by 576 pixels, or picture elements, to Page 5, 6, 7 . other enhancements were demonstrated fIll the television screen with the high- to a technical committee of the quality picture. For the experimental DIGITAL TRANSCODER European Broadcasting Union (EBU) on transmission, a montage of the startling Page 8 February lIth, and at a meeting of the pictures of Saturn taken from the Institution of Electrical Engineers (lEE) Voyager 2 spacecraft was used to NCl RE-ENTERS SERVICE on March 8th. The UK teletext system demonstrate the capability of the Page 9 has, for many years now, represented an system. The picture was fed from a efficient and rugged way of trans- conventional 35 mm slide scanner into 4000 VPR 2'S mitting, receiving and decoding data for the digital picture store. After sampling Page 10 display on a television receiver. None of at 13.5 MHz it was fed to a the efficiency or ruggedness is lost in microcomputer and data generator that RADIO MAINTENANCE the transmission of the enhancements. sorted the information into a form Page 10 The recent transmissions were the suitable for transmission. The special culmination of several years work by equipment was used temporarily to TRANSPORT DEPT. COMPUTER engineers from Special Projects Section replace two of the conventional four Page 11 at Research Department. The line Ceefax signals on BBC 2 for the equipment used to generate the transmission. STEERABLE ARRAY enhancements contained a teletext The Voyager 2 picture was Page 11 generator. a microcomputer system and included in a series of pages that a high-quality digital picture store. displayed an improved character font. SILVER STREAK LICENSED whose content was displayed on a The new character generator in the Page 12 screen. On the UK television standard decoding equipment enabled the (System 1) the store opcrates at thc characters to be more easily read, with AWARD TO ENGINEERS CCIR recommended sampling rate of individual characters being weJI spaced Page 12 13.5 MJ-Iz. with 8-bit Red, Green and 'continued on Page 3' 'ENG INF' Spring 1982 - Page 1 Editorial The recent announcement that the BBC is to be allowed to operate two satellite channels has been welcomed. Thus the BBC enters another era of broadcasting. As technology has improved, so have the services which the BBC has been able to offer its audience. None of these improvements would have been possible without the dedication and skill of BBC engineers. For many years now BBC engineers have been investigating the problems to be found in the 12 GHz band, and seeking solutions. Some of the problems have been answered, others await international agreement. Fifty years ago the BBC entered a new era when it moved its headquarters from Savoy Place to Broadcasting House. At that time the Press were quick to blame the BBC's high-power medium-wave transmitters for the series of wet summers that had been The following 405 line transmitters experienced. With the advent of are expected to close as shown: satellites, how long before the Press 1983 make this accusation about satellite BBC Transmitters - First Quarter broadcasting? Bath (Avon) Congratulations Weymouth (Dorset) Mr. Peter Rainger, Deputy Direct- Manningtree (Essex) or of Engineering, has been elected Wensleydale (N. Yorkshire) a Fellow of the Royal Society for Richmond (N. Yorkshire) Weardale (Co. Durham) contributions to electronic techniques Llangollen (Clwyd) used in television. Our warmest Newry (Co. Down) congratulations to him. Frank Be"isford, Assistant Head Wenvoe Channel I3 (South Glamorgan) Welcome of Engineering Information We welcome Keith Hunter from IBA Transmitters -First Quarter Department, retired on 1st March after Bath (Avon) VT in Cardiff to our team of 25 years' service. Ridge Hill (Hereford) contributors. Keith has kindly agreed . After serving in the Royal Navy S1. Hilary Channel 10 (South Glamorgan) to supply Eng Inf with cartoons, and an BBC Transmitters Second Quarter example of his excellent work is from 1940 till 1946 and in Government - Bamstaple (N. Devon) published elsewhere on this page. We Communications until 1956, Frank joined the BBC as an Engineer in Thrumster (Caithness) look forward to seeing some more of his Orkney cartoons in the future. Broadcasting House. He moved to External Services in 1958 and became a Bressay (Shetland) Alan Lafferty Senior Maintenance Engineer at the Grantown (Badenoch & Strathspey) Caversham monitoring station three Kingussie (Badenoch & Strathspey) Transmitters years later. Ammanford (Dyfed) Opened Frank is probably best known for Kilvey Hill (Swansea) his work in E.I.D. which he joined in Llanidloes (powys) The following uhf tv relay stations have 1964. His wide knowledge and IBA Transmitters -Second Quarter opened since January: enthusiasm ensured that the public, the Huntshaw Cross (N. Devon) Ipstones Edge, Staffordshire retail trade, and the radio and television Rumster Forest (Caithness) Romaldkirk, Co. Durham industry were all reliably informed Aviemore (Badenoch & Strathspey) Weaverthorpe, North Yorkshire about BBC engineering developments, BBC Transmitters -Third Quarter Wivenhoe Park, Essex particularly those affecting transmission Douglas (Isle of Man) Newry South, Co. Down or reception. There can be few Ballater (Kincardine & Deeside) Llanharan, Mid Glamorgan representatives of the industry that have Toward (Argyll) St. Anthony-in-Roseland, Cornwall not heard his witty explanations of BBC Lochgilphead (Argyll) . Bretch Hill, Oxon policy from some platform or other. Rosneath (Dumbarton) West Wycombe, Buckinghamshire Since he became A.H.E.I.D. three Millburn Muir (Dumbarton) Coleford, Gloucestershire years ago Frank has represented the IBA Transmitters -Third Quarter Pinwherry, Strathclyde BBC in many negotiations with the Richmond Hill (Isle of Man) Ballantrae, Strathclyde Home Office on frequency planning and Whitehaven (Cumbria) Vhf Radio policy matters. Rothesay (Argyll) Wrotham -now mixed polarisation Phil Laven, the BBC's Senior Rosneath (Dumbarton) Local Radio Engineer in New York for the last three BBC Transmitters -Fourth Quarter Radio Guernsey - Rohais (mf only) years, takes over as the new Assistant Lame (Co. Antrim) Radio Jersey -Trinity (mf only) Head. Whitby (N. Yorkshire) Page 2 - 'ENG INF' Spring 1982 "ENHANCED CEEFAX" Electronic Stills Store Evaluated 'continued from Page l' An experimental prototype of an the new digital coding standard. The in the words. electronic store for still pictures was main signal storage is provided by one Another innovation that was constructed for studio operation to of the latest 8" Winchester magnetic broadcast was "linked pages". In the enable pictures originated in electronic disc drives which is completely sealed. present Ceefax system there are often form to be stored and selected for trans- Two digital semiconductor picture pages where the content has some mission at the studio. stores are used as buffer stores. relevance to another page in the The need for such a stills store Operation of the equipment is magazine. Viewers wishing to retrieve was identified some time ago. controlled by a Z80.based the additional pages need to re-select Traditionally, artwork and captions, microprocessor which also provides the page number and wait for the etc., have been photographed and slides picture processing for grabbing moving magazine to cycle round until they produced, and these have been pictures. receive them. Using "linked pages" the broadcast using a studio slide scanner. Initial tests with the prototype Ceefax Editor would decide which pages More recently, however, direct studio store were most encouraging and were associated with each other, and electronic methods have become showed that such a system could be would add extra information to link available for originating many of these readily incorporated into existing them together. In the enhanced signals. Extensive use is. now made 0f studios. Throughout last December and decoder the pages would be stored and electronic character generators and the January, the prototype studio store was instantly displayed when the relevant BBC Broadcast Computer is also used in installed in the apparatus room of TC7 . linked page number was selected. For the generation of electronic pictures. It was established that the unit could example, the news index on page 201 With the advent of new electronic provide an extremely valuable general on BBC 2 could be linked to graphic drawing systems like 'Flair', it studio facility. Studio cameras were background information, news head- has become important that studios are used to enable still pictures of general lines, and complete news stories which provided with an all-electronic studio activities or artwork to be stored. the viewer could retrieve at the touch of equivalent of the slide scanner. It was also found to be beneficial to a button without waiting for the The prototype studio store store signals from the slide scanner so magazine