---- -- ,,- -.-.-- - .- , - -,-.- -~ .... - --- , -- ., ., No.20- Spring1985 The Quarterly for BBC Engineering Staff Please Circulate BBC 1 - Bright New World Recently many viewers will have Descrip tion by a spotlight above tlte viewer. noticed a new look to BBC 1. For The symbol generated by the many years the channel logo has equipment is a rotating image of Design been the familiar 'rotating world', the world with a caption displayed Graphic Design at Television generated from a mechanical beneath. The image is larger than Centre undertook the artistic model. Originally this was pro- its predecessor, and there is no design of the symbol. Clearly this duced by a remotely controlled reflecting mirror, but the detail had to be done in very close con- camera, affectionately known as and accuracy are much greater. junction with the engineers in Nod dy, which was also used for the old mechanical clock and fault captions. Most of Noddy's functions have been replaced by electronic generators, but the World was still being produced by a caption scanner, followed by a colour synthesiser and PAL coder. This required regular maintenance, and alignment of the video pro- cessing to produce consistent resul ts. On February 18th a new Symbol was introduced. The generating equipment is all electronic, using the latest digital techniq ues. Some digitally generated pictures suffer from an effect known as 'aliassing'; this is most noticable on sloping lines and circles as small steps, which show the graphic being made up of discrete lines. The new equipment is fully 'anti-aliassed' on both the logo and the captions, which sub- stantially improves the overall The caption is customised for each Designs Department. Over the last quality. of the various regions. few years, with the design of By using internal frame stores The symbol of the world several electronic graphic devices, there is no restriction on the comprises three coloured parts. A a good relationship has developed colours, which can be properly gold shell, which is painted black between the two disciplines. While shaded. Since the colour inform- on the inside, with a shaded blue neither party fully understands ation is internally stored there is disc behind it. The sea areas are the restrictions and principles of no need for an external synthesiser etched away, leaving the land the other, each now has a good or clipper, thus reducing both day- masses highlighted in gold on the grasp. of one anothers limitations. to-day and long-term variations. outer surface, and black on the Interestingly this even transcends All National and Regional Centres inner surface. Where the shell is the use of jargon. which opt-out of BBC I have been completely transparent, that is provided with their own equipment Designs Department devel- where there is sea on the front and oped the principles of the system. whose outputs, apart from their back, then the shaded blue disc is The most important part of this customised caption, are all seen. The outside is highlighted to was the data compression format identical and of consistent quality. make it appear as though it is lit continued on page 8 'ENG /NF'Spring /985 - Page 1 \ Editorial I Do you cringe when you hear disc- jockeys refer to "97.5 FM" or "1548 kHz medium-wave"? (It is almost as infuriating as hearing ten pence referred to as ten pee!) These "station idents" as they are known, are intended to tell the audience which station they are listening to should they have tuned-in by chance. But they are, to say the least, contradictory, since 1548 kHz refers to frequency and not wavelength; similarly 97.5 refers to the VHF band and not to the modulation system. For those Brian Marsden (left) from GEC McMichael, and ADE, Charles Sandbank whose notes at Wood Norton have sign a licence agreement that allows GEC McMichael to manufacture and long since gathered dust in the market the CD3M/546 digital PAL decoder attic, the wavelength in metres disc-jockeys and presenters should it is likely that "FM" will be equals 300,000 divided by the use phrases that listeners are more adopted, and your editor will be frequency in kilohertz; thus familiar with. in a permanent state of cringe! 1548 kHz equals a wavelength of I~ an attempt to persuade Incidently, in technical writ- about 194 metres. The correct more hsteners to use Band 11,BBC ings it is right and proper to use phrases, from an engineer's point Radio has tried to formalize this VHF MF LF and HF when of view, are therefore "97.5 MHz situatio~, by sug~~s~ing that the refer;ing t~ frequencies, and FM, VHF and 1548 kHz medium phr~s~ VHF-F~ 1S used, thus AM, PCM, DPSK etc when referring frequency". However, research has aVOldmg a con~'hct between engin- to modulation systems. shown that very few radio receivers e~rs and the hsten~rs. .Eventually There are no prizes for (or should I call them sets?) have e1ther VHF or FM w1ll become guessing which service might carry tuning dials marked "VHF and normal as the listeners become a signal via NICAM 3/PCM, FM, MF"; they are far more likely to accustomed to the phraseology, and DPSK with C-MAC E-MAC be marked "FM and AM or MW". and the alternative phrase will be D2-MAC, or B-MAC in Band VI: Therefore it makes sense that the dropped. Sadly for the engineers, Answers on the back of a 500 pee note to my office please! The Cost of ITV Alan Lafferty The following article from Corporate Publicity provides some useful facts when discussing the BBC's finances: Transmitters Opened Figures provided by MEAL, the market research organisation, to the 'Did You See ?' programme on the financing of broadcasting (Sunday 10 February) show in detail the amounts paid by consumers towards ITV The following uhf transmitters and Channel 4 through the shopping basket. have opened since January: Out of a basket of everyday goods which cost a total of £6.20, the following amounts go towards the cost of television advertising: Upper Soudley Glos Occom be Valley Devon ( Chocolate 200 g 1.74 P Cheselbourne Dorset Crisps 150 g 0.84 p Bidston Merseyside Cereal 150 g 2.75 p St. Albans Herts Tea Bags 80 1.81 p Stokein teignhead Devon Cat Food 415 g 0.56 p Inverness Highland Soap 142 g 1.43p Gellifendigaid Mid. Glam Toothpaste 175 ml 8.28 p Tregynon Powys Stockcu bes 24 5.27 p Deodorant 150 p 8.91 p The following vhf transmitters have opened or changed: Total cost of products £6.20 31.59p to TV advertising costs Ludlow Salop MEAL reports that the most heavily advertised group of products are Brougher Mtn. Co. Fermanagh baby care items. A box of disposable nappies costing £3.25 contains in its Lame Co. Antrim price 47.61p for television advertising - 14.6% of its price. The price of a family car (1.6HL) includes £24.40 for television The following local radio trans- advertising. mitter has changed: All prices provided by MEAL include an allowance for airtime discounts and for agency commission'. Les Touillets Guernsey Cl Page 2 - 'ENC INF' Spring 1985 different ~upplier, and a different So, in 1979, a BBC specifi- TV 36 set of problems emerged. These cation for TV36 type cable was cables had all the same colour produced, this being coded Camera Cable insulation (white) on the inner PIF36/1M. Initially this specifi- conductors and sadly little cation called for three versions, A, One of the necessary parts of a attention was given to the B, and C (rubber, polyurethane television studio is the camera and allocation of conductor functions and pvc sheaths respectively). The lens, and a lot of time is spent or pin layout. Thus syncs could resulting cables were free of earlier maintaining and lining them up run next to talk-back circuits, problems of return loss, colour before use. In the last few years resul ting in a permanent buzz on coding of cores, and the lie of the however, one of the weak links in the cameraman's headphones. This cable. After further development a the chain has been the multi-core problem was particularly evident single cable, the 'D' version, with an camera cable, now known as on the Philips LDK series cameras. overall diameter of 17.5 mm, TV36, that connects the camera All TV36 cable up to this date sheathed in Arctic grade pvc, was to the studio control rooms. With was designed for use with baseband produced. This improved the recent modifications it is hoped frequencies, and it could ha.ve a flexibility and avoided the 'squeak' that the problems associated with poor return loss when multIp~ex problem which occurred on some the cable and its terminating signals up to 27 MHz were bemg studio floors with the polyurethane connector will be resolved. carried. Slight differences between sheathed cable. It was also thick F or non tv-studio engineers it manufacturers' designs resulted in enough to prevent it going under is perhaps worth considering what connectors that did not mate, pedestal guards. The 'D' version the cable does, and what the problems were. As the name suggests, the cable has thirty-six Outer inner core conductors carrying the cover Clar;nping Groove for moulding camera picture outputs, camera s~:~~s locat!ng controls, talk-back and intercom, clamping . Clamp nut syncs etc. between the studio or OB and production control areas. A cross-section through the cable shows its complexity.