No.6 - Autumn 1981

The Quarterly For BBC Engineering StaH

Cameraman Chris Wickham covers the procession from St. Clement Danes Church

The Royal Wedding on July 29th was the largest single outside broadcastever mounted by OB's. Production facilities involved some seventeen Colour MobileControl Rooms (CMCR's) and over sixty cameras, providing cover of all the weddingcelebrations nationwide. 109 broadcasting organisations from 74 countries took thepictures to an estimated worldwide audience of 750 million viewers. In this specialfeature we take a look behind the scenes at some of the facilities and people thatmade the broadcast possible.

The engineer behind the broadcastwas Frank Hughes, Head of EngineeringPlanning at Kendal Avenue "It was justlike any other outside broadcast really",said Frank, "except on a larger scale."TechnIcal planning for the broadcasthad been going on ever since theengagement announcement in March.Some of the early plans had to bechanged when clearance for camerapositions was refused by the Police;other details, such as the honeymoondeparture point, were only known a fewdays in advance.

Focal point for the outsidebroadcast was the Colour MobileCentral Control Room (CMCCR) whichwas located at St. Paul's Cathedral andhad only entered service in April for theBoat Race (Eng Inf No. 4). It wasdesigned by Bill Rhodes of SCPD andhis team with broadcasts such as RoyalCeremonials, Open Golf Championships

and Wimbledon Tennis in mind.In productions involving many

cameras or other sources, it is notpossible to display all of the inputs onmonitors because of the limited numberavailable in a conventional CMCR. Evenadding additional monitors creates aproblem because of the limited spaceavailable. Vehicles of conventionalroadwidth are just too small for the job,so the CMCCR uses an unusual designto overcome the problem. The sides ofthe production area in the middle ofthe vehcile are expanded by 1 metre oneach side, increasing the width from2.4 metres to 4.4 metres. This allows abank of thirty-four monochrome andfour colour monitors to be seen by allof the production staff at the controldesk, and all of the picture sources cannormally be displayed. For the Royal

'continued on page 3'

In this edition ofENG 'Nf:

The RoyalWedding

pages 1,3-10and12

Wrothammixed

polarisationpage 2

Transmittersopened page 2

SatelliteTerminal

made by RDpage 11

Editorialpage 2

'ENG INF' Autumn 1981 - Page

Wrotham - mixed polarisation

h.l the end of this year the vhf/fmtransmissions from Wrotham forLondon and the south-east of Englandwill change to mixed polarisation. Itwill be the first high power station inthe country (and probably in Europe)to use this form of transmission. Ineffect, the power of the transmission isbeing doubled by the addition of anequal vertically-polarized component tothe existing horizontally-polarized one.The change is being made to givebetterreception to listeners with portableradios and those in cars, all of whom

TransmittersOpened

The following uhf tv relay stations haveopened since June:JuneKirkoswald, StrathclydeBroad Haven, DyfedCrucorney, GwentDelph, Greater ManchesterUnion Mills, Isle of ManBackwell, AvonJulyLauder, BordersStow, BordersMonmouth, GwentDolwyddelan, GwyneddLlanarmon-yn-Ial, ClwydCerrigydrudion, ClwydSunderland, Tyne & WearCartmel, CumbriaUrswick, CumbriaStaveley-in-Cartmel, CumbriaHawkshead, CumbriaKettlewell, N. YorksAugustCollafirth Hill, Shetland IslesBeer, DevonBelper, DerbyshireSeptemberKirkfieldbank, StrathclydeMethven,Tayside .

Strathallan, TaysideFintry, Central ScotlandFishguard, DyfedGilfrew, West GlamorganGulval, CornwallMillbrook, HantsPenny Bridge, CumbriaBackbarrow, CumbriaTransmitter ChangesVhf -AugustMynydd Pencarreg, Dyfed - new vhf 3service stationLocal RadioJune - Radio Leicester goes stereoAugust -Radio Medway: Extension ofservice to Tunbridge and RoyalTunbridge Wells.

'HNGINF' Autumn 1981 - Page 2

tend to use simple vertical aerials.Research Department investigationsover the past few years indicate thatthese listeners should get a benefitequivalent to increasing power on thepresent polarization between four andeight times. Listeners who use fixedroof-top or loft aerials are asked tomake no change to their installationsand should not notice any significantdifference in reception on them. (Theremay be small differences owing to theinability to match the radiation patternsof the new aerial precisely to those ofthe existing one).

Some local radio stations,. andthose relay stations recently built in thenational regions, already radiate mixedpolarisation although it may have beengiven a different name. . Slantpolarization implies that the vertical andhorizontal components are in phase,whereas circular polarization impliesthat they are in phase quadrature. Onsmall, simple aerials it is possible toachieve either of these conditions, buton large and complicated aerials likeWrotham the phase difference betweenthe components varies with azimuth sothat in most directions the polarizationis neither slant nor circular butelliptical. Accordingly the more generalterm mixed polarization has beenadopted to cover all these conditions.

The work at Wrotham startedwith the installation by TransmitterCapital Projects Department (T.C.P.D.)of four new Pye 10 kW transmitters tocarry the Radio 2 and 3 transmissionstemporarily while the' Architects andCivil Engineers Department (A.C.E.D.)modified the building ready for all thenew equipment. Since then a new masthas been built and the outside work onaerials and feeders completed. Insidethe building the installation of six new20 kW Marconi transmitters is welladvanced and the transmitter combiningunits are now in the preliminary stagesof installation. The project also involvesnew monitoring and control gear, drivesand auto-phasing equipment.Commissioning tests are due to start inNovember for service by the end of theyear. . .

This is the first station m amassive programme of re-engineeringbeing carried out by T.C.P.D. andA.C.E.D. covering all ninety-one largeand small vhf stations in the UK. Thenext major stations to be re-engineeredare Sutton Coldfield and Holme Moss(by 1983) and the whole programme isscheduled for completion by 1989.

* * *

EditorialOctober has been designated

"National Teletext Month", by theDepartment of Industry and the publicare being bombarded with informationabout the new facilities available. Tocoincide with the promotion, the BBCwill increase the number of linescarrying data information from two tofour, halving the page access t~e,and removing one of the majorcriticisms of the system. It isencouraging to see that development ofthe system continues at ResearchDepartment, with work on improvedgraphics, rounded character sets, andphotographic quality pictures which willenhance the basic system in years tocome.

The viewer should not fear thesechanges, however, as all of t~edevelopments and enhancements willretain the overall compatibility withexisting decoders.

BBC engineers can be proud thatthey have introduced a revolutionaryservice, and that broadcaster,manufacturer and public will all benefit.

ROYAL WEDDING

This letter is one of many receivedfrom grateful viewers. Well done allconcerned.

Dolwyddelan,Gwynedd,

Wales.Dear Sirs,

Would you kindly convey to allthose responsible and all those whohelped them, our most grateful thanksfor the new transmitter to serve thisvillage: more especially for getting itfunctioning in time for the RoyalWedding.

Many of us have writtengrumbling letters in the past, so myhusband and I wanted to say "Thankyou" for the superbly improved t.V.picture we now receive - very muchappreciated.

Yours gratefully, .(Mrs.) Dorothy Valentine

'continued from page l'

The Royal Wedding

BBC cameras were in position long before the procession passed

Wedding an extra eight monochrome wedding and carried three Link 110 andmonitors were mounted on racking; the one Link 120 camera. Special ductsadditional space created by the were constructed under Constitutionexpanding sides allowing plenty of room Hill to carry the triaxial camera controlto accommodate them. The extra space and other cables from Buckinghamalso allows greater freedom of move- Palace camera positions to the CMCR's.ment for staff around the control desk. Sound and vision signals from theseAt the rear of the vehicle is a sound area cameras were mixed locally, and passedwith a 44 channel Neve stereo sound to the CMCCR at St. Paul's Cathedralmixer and a central communications via an shf radio link. Commentarysystem, the heart of which is a boxes were established on Queen50 x 100 pin-board matrix which Victoria's memorial in the middle ofenables the system to be tailored to suit The Mall, and emergency commentaryeach broadcast. The front of the vehicle facilities were provided in the Welshcontains engineering and vision control, scanner just in case the crowds provedwhere all of the vision signals from the to be too dense for the commentator,smaller CMCR's were fed to the CMCCRallowing Michael Lum1ey the Producer,to have complete production contro1.

Near Buckingham Palace atechnical area was established behindthe wrought iron work of Canada Gate,in the corner of Green Park. ThamesTelevision, CBC and ABC shared thesite, which soon became festooned withcables and cameras.

The BBC had two type 5 CMCR'sin the Park. These vehicles carry a

normal complement of four cameras,although they can accommodate up toeight with the associated control equip-ment. Vision mixing is effected on anABCD mixer, and a Neve 24 chaimelsound desk handles the sound mixing.One of the CMCR's, L02, carried a fullcomplement of eight Philips LDK5cameras, which were mounted in andaround the Buckingham Palace area.The second CMCR was detached fromthe BBC Cardiff OB base for the Radio OB caravansat Canada Gate

Tom Fleming, to reach the commentarybox; fortunately this "facility was notrequired.

Further along The Mall anotherCMCR, L03, had been sited byengineering manager John Livingstoneclose to Admiralty Arch. Six PhilipsLDK5 cameras were connected to thisvehicle, one of which was mountedon top of the Arch itself, providing thehigh level shots of the processions inThe Mall. Local sound and visionmixing were available to the director,Peter Cleaver, on this, the latest of thetype 5 scanners. The output of thisvehicle was, like the vehicles at GreenPark, connected to the CMCCR atSt. Paul's Cathedral via an shf radiolink.

The London skyline is not helpfulto the communications engineers whorequire a clear line-of-site path for theshf radio link equipment. An inter-mediate relay point was thereforeestablished, on top of New ZealandHouse in Pall Mall. Several shf linkswere established, four relaying signals toSt. Paul's and one to Television Centre.A single LDK5 camera was alsomounted on New Zealand House,providing the spectacular aerial shotsacross the roofs of central London.

In The Strand, Don Craske hadbrought a three camera CMCR from theOpen University production centre atMilton Keynes. Link 110 cameras hadbeen removed from the studios for thebroadcast, and these were mounted onSimon hoists which had been parked inside roads leading from The Strand. A'continued on page 4'

'ENG INF' Autumn 1981 - Page 3

'continued from page 3'

The Royal Wedding

Cameraman Ken Moia outside Buckingham Palace

single-camera unit carrying an EMI200 I camera was located nearby, and itsoutput was fed to the Open UniversityCMCR. Local mixingwas providedforthe director, Ken Griffin, the outputbeing fed to St. Paul's Cathedral viawide-band underground cables providedby British Telecom.

Three Philips LDKS cameras wereconnected to another CMCR nearTemple Bar, where Peter Greenyer hadobtained permission for the vehicle topark in the yard of the Royal Courts ofJustice. One camera was located in themiddle of the road, on the island by St.Clement Danes Church, and another waslocated on a Simon hoist in Bell Yard.The third was located on scaffoldingprotruding from a solicitor's office inFleet Street, where the platform had tobe counter-balanced to prevent thecamera, and Jerry Ellis the cameraman,toppling into the crowds on the narrowstreets below. The platform wascleverly concealed behind red, whiteand blue bunting specially bought forthe occasion by Peter Greenyer."Concealing the platform was noproblem" says Peter, "it was the 4kmcable run around the back streets to theCMCR that caused the biggestheadache!" British Telecom, onceagain, provided wideband undergroundcables from the CMCR to St. Paul'sCathedral.

At St. Paul's Cathedral a specialfence was erected around the complexof outside broadcast vehicles. The shfradio links were sited high up on theCathedral roof by Roy Carpenter whowas responsible for co-ordinating thecommunications for the broadcast.

'ENG INF' Autumn 1981 - Page 4

The communication facilities forthe broadcast were complex, with eachof the local cameras requiring talk-backfacilities, as well to the CMCR's locatedalong the route. The MobileCommunications Area vehicle (MCA)housed all of the radio equipment usedfor the broadcast, as well as sixindependent vhf radio telephonesystems used for talk-back. The vehiclehas facilities for monitoring and qualitychecking both the shf radio links, andthe lines provided by British Telecom;after any necessary correction thesignals were passed to the CMCCRnearby.

As well as the CMCCR and MCA,under the watchful eye of John Kempthe engineering manager, two type

5 CMCR's and a two-camera CMCRwere co-located in this area. Theseprovided the base-stations for theeighteen cameras in and around St.Paul's Cathedral. A Philips LDKScamera was mounted on the roof of theAbbey Life building overlooking thewest door of the Cathedral, where thedifficulty of laying cables was overcomeby using radio-data control equipmentto connect the camera to its basestation. Another camera was mountedon Queen Anne's statue, where specialscreens were painted to match thesurrounding stonework, and afforded adegree of camouflage. Inside theCathedral the cameras were alsomounted and decorated so that theyblended with the natural surroundings.

From St. Paul's Cathedral twoseparate outputs from the CMCCRwere fed via two individual shf radiolinks and wideband cables to studio 6 inTelevision Centre, where Angela Ripponand Michael Woods provided linkingmaterial and interviews. Next door, instudio 7, forty commentalY positionswere rigged for use by foreignbroadcasting organisationscommentating "off-tube".

Programme feeds were madeavailable to the EBU headquarters inBrussels for distribution around Europe,and to three Intelsat satellites,one over the Indian Ocean for receptionand distribution to Asia, and two overthe Atlantic for North and SouthAmerica. Over fifty countries took thebroadcast live: a two camera CMCRwas made available to foreign broadcast

--Cameraman Jack Hayward mounts his LDK 514 in the Golden Gallery

organisation's for in-vision shots ofnational cornment<~tors; it was locatedoutside Buckingham Palace.

The honeymoon departure fromBuckingham Palace to Waterloo Stationw~ covered by the same cameras in TheMall that had covered the earlierwedding procession. A Scottish type 5CMCR and the lightweight productionunit (LPU) were at Waterloo Station.Other units were hired from TVInternational and Trillion to cover theroute from Horse Guards Parade intoWhitehall, in Parliament Square, and attounty Hall.

After the honeymoon departurethe OB crews worked quickly to de-rigthe vehicles and cameras so that theycould be re-deployed onto otherlocations. Two days later the sameunits were covering athletics fromCrystal Palace, showjumping fromHickstead and the ''Much Loved MusicShow".

LIGHTING A ROYAL WEDDINGby Bryan WiIkes, Head of ,Lighting,Television Outside Broadcasts

For some in BBC Television theRoyal Wedding was, in many ways, justanother multi-camera OutsideBroadcast, following the pattern set byprevious Royal events. However, thisone proved to be different -the sense ofoccasion did 'get to' some of thesteeliest professionals, when it wasrealised this would be 'The Wedding ofthe Century' with probably the biggest'live' audience of all time. around 600million or even more -like a country'sGNP, figures of this magnitude aredifferent to comprehend.

What distinguished the event forbroadcasters was not only its scale andits setting but its significance in the lifeof the nation . the wedding of ourfuture King and Queen -which meantthat it would be the most importantOB for some time, demandingmeticulous planning and execution andthe best resources available. Lightingalone accounted for nearly £100,000of combined BBC and ITV cash, anexpenditure in modern lightingtechnology unparalleled in the historyof Outside Broadcasts.

Because the venue for theWedding was not immediately known, Iassumed, like many others that it wouldbe Westminster Abbey, but quicklylearned that it was to be St. Paul'sCathedral, giving me a bigger and loftierbuilding to light. Just as impressive, butin a different way. Of course, previousbroadcasts from St. Paul's had paved theway; we had last lit the Cathedral forthe Queen Mother's 80th birthday, andbefore that there had been QueenElizabeth's Jubilee Service' and

One of the camera positions in The Mall

Sir Winston Churchill's Funeral Service.But, with the developments which hadtaken place in lighting technology andthe improved standards, we could nowachieve a higher incident level for alower Kilowattage.

After several sessions at theCathedral with producer MichaelLumley and ITV's Jim Pople, I preparedan outline lighting plot relating lights tocamera positions, and then discussed thearrangements with Lee Electric(Lighting) Ltd., Wembley. Lee hold theBBC contract for all OB lighting in theUK and EEC countries. In this case ITVhad already agreed that we shoulddesign and organise the lighting, withITV sharing the costs. Three Movietonefilm cameramen and over 50 stillsphotographers' selected to cover theWedding would automatically benefittoo.

Lee management indicated thatthey could meet our needs from theirextensive stock of equipment, relyingon the high-technology Thorn CSI(compact source iodide) and CID(compact iodide, daylight) lamps formost of the lighting because of theirsuperior efficacy and colour stability.

I wanted to light the Cathedral toa level of at least 1700 lux, so thatcameras could use aperture settings ofaround f4 . 5.6 achieving good depth offield and the best optical performancefrom their lenses. In previousbroadcasts we had barely bettered 1000lux, leaving cameras operating atmaximum lens aperture with thedifficulties of short depth of field whenzoomed into narrow angle of view.

When I had completed my lightingplot, a number of visits were necessary'continued on page 6'

Lighting the Wedding required some 270 or more luminaires

'ENG INF' Autumn 1981 - Page 5

'continued from page 5'

Bryan Wilkes checks the lighting levelsinside the Cathedral

to the Cathedral, with my ElectricalSupervisor, to detail our layout and planthe installation. This involved liaisingwith a number of different authoritiesincluding the Receiver of St. Paul's andhis Clerk of Works, London ElectricityBoard who would provide the power,and with the police over security.Camera dispositions

Eventually it was decided by theproducer that twelve camera positionswere required to enable us to cover theceremony adequately, and ITV usednine. Several of these were jointpositions at which our own Philipscamera was located next to ITV'sMarconi or Philips equipment.Fortunately the movements of the mainparticipants in the ceremony were to befairly straightforward. Our chosencamera positions would be able to cover

. the full ceremony and congregationquite easily.

A camera high above the WestPortico would proVide a wide angle shotof the Cathedral, with the ability tozoom into closer shots in the Nave andChancel. Another camera on the Northside of the aisle just inside the WestPortico with a lens height of about 8feet provided pictures of arrivals. Thelighting in this area was provided byeight of Thorn's 2.5kW CID andfourteen IkW CID. I found the colourtemperature of 5,500K an admirablematch with the daylight pouringthrough the West Door. ITV had asimilar camera position on the Southside of the aisle. The respective vision,engineers ,had been briefed beforehand

'ENG INF' Autumn 1981 - Page 6

The Royal Weddingthat as the cameras panned away fromthe CID lit area there would be agradual transition of colour temperaturefrom 5500 to 4300K, the Nave and theremainder of the Cathedral being lit byThorns lkW CSI lamps in the LeeElectric designed housings, known as -lK single and Twin CSI. This change ofcolour temperature extended over anarea of some 30 feet by mixing CSI andCID light, until the CSI colour tookover completely. This worked well inpractice - camera colour balancingcontrols only needing Sligllt adjustmentin vision - as we now know the changewas not obvious on the screen. Furthereastwards along the Nave, cameras werepositioned on both sides of the mainaisle and in the North and SouthTransepts. One camera was positionedin the North Transept by the Font -providing a side-on shot of the BachChoir and the Symphony Orchestra.Two large windows in this area eachtwenty-two foot by ten foot had tobe colour corrected by using acombined filter of .3 neutraldensity/orange which prevented a bluecast from falling across the Choir.Three other large windows on the Southside of the Cathedral had fIlter framesfIxed to the exterior of the windows, .

each with .6 N.D./orange correctionfIlter which reduced and corrected theincoming sunlight by 2 stops.

Other cameras were positionedbehind the Royal Family and EarlSpencer's family in the N.E. and S.E.'transept aisles. They were able toprovide frontal sQ.otsof the respective

.\I'

.The orange plastic filter stretched overone of the Cathedral windows

families as well as side shots of PrinceCharles and Lady Diana, also shots ofguests sitting under the Dome area -mainly close friends of the Bride andGroom and the Crowned Heads ofcountries around the world. A cameraplaced just above the North Choir stallsgave an 'over the shoulder' (theArchbishop's) shot of the couple. Twomore cameras placed at East and Westsides of the Whispering Gallery wereable to zoom the length of the Nave andto the Altar. One fmal camera - givingthe now well known shot lookingvertically down from the centre of theDome completed the disposition ofcameras within the Cathedral.

Lighting equipment in the triforium is adjusted

The Bach Choir of some 200members - complete with opera singer,Kiri Te Kanawa, and a symphony

-orchestra all under the direction ofSir David Wilcocks were to add so muchto this Royal occasion by the majestyof their music. Lighting this largenumber' of people squeezed into theNorth Transept for close-up shotsproved to be difficult: the angle fromthe Triforium above them was verysteep, too steep for a pleasant keylighteffect. I had no alternative but to usea number of Twin CSI lampheads fromthe South side of the Dome - an areaknown locally as the South WestQuarter Dome -lamp to subject distanceof some 200 feet! Diffused spotspreader lenses did the trick and allowedme to skate the light past an immensechandelier, without creating a shadowproblem. Other lighting of the Choirand Orchestra was done from a lowerlevel - 29 feet high each side of therostra -CSI with medium angle spreaderlenses and 2kW I.Q. lamps provided thenecessary incident level, the latter beingcolour corrected to match the CSI.The Dome

At floor level, under the Domethere is a seating area of some 150 feetin diameter. The nearest position forlampheads is in three of the four quarterdomes, the fourth being forbiddenterritory - it's full of organ equipment!The quarter domes are above the levelof the Triforium and even further awayfrom the subject. For such a large areaand a tremendous throw for the lamps,I used three Dino-lights on molevatorstands each with 24 x lkW PAR 64Thorn lamps, colour corrected to matchCSI: they provided an incident level of1,400 lux. To this I added 12 x TwinCSI bringingthe levelup to 1,700 lux _

the CSI's providing that extra punch

Michael Lumley checks out the mixing desk in the CMCCR2

and sparkle. The interior of the Dome enhanced the mosaics by giving them ahas eight frescoespainted by Sir lames warmcast -adding richness.ThornhiIl, illustrating the life of Altogether 273 Thorn lkW CSISt. Paul. Six twin CSIs on the lamps in Lee fittings were installed.Whispering Gallery lit these to a level Most of these were in fixed positions,that allowed the cameras to zoom into but seven CSI twin fittings in theextreme narrow angle and gave many Whispering Gallery were on moveablepeople - viewers, and those present - stands. The fixed lampheads weretheir first clear glimpse of his work. clamped to scaffold tubing installed onThe ceiling mosaics above the Choir and the narrow Triforium by St. Paul'sAltar - gold and delicate shades of blues, scaffolders and at the lower level bygreens and reds, needed a different Lee Scaffolding Ltd.lighting technique to enhance the In my view, CSI was the onlycolours and to make the gold sparkle practical choice for this event. In theeven more than it normally does. This old days, we would have had to rely onwas achieved by using uncorrected PAR lOkW tungsten lamps, with their36 lamps in Lee's eight-light fittings attendant problems of bulk, weigllt andpositioned in the Triforium. By using heat. I have calculated that our totalthe cameras colour balanced for the electrical load for lighting would thenceremony to CSI lamps and without have been 1.6MW rather than therebalancing them for the lower blue gain 690kW we actually used. CSI hassetting on the camera control unit, it proved to be a valuable lamp for OB's;

the BBC was the first to recognise itspotential in our specialised field andworked closely with Thorn as theydeveloped it as a Source able to meet thestringent requirements of TV lightingdirectors and film cameramen. Wehave now used it successfully for adecade. The lamp has revolutionisedlocation lighting of some events, andwithout it we would have needed two orthree times the 17 tons of lightingequipment that was eventually movedinto St. Paul's. The only other possiblealternative, CID lamps throughout theCathedral, would have resulted in evenbetter colour rendering for the cameras,but would have meant a 15% powerpenalty. In any case, the CID lamp _

while promisingmuch for the future _

is still relatively new and we could takeno chances on this occasion.

This camera covers the North Choir during rehearsals'continued on page 8'

'ENG INF' Autumn 1981 - Page 7

'continued from page 7'

The Royal Wedding

The expanded sides of the CMCCR 2

With CSI there are few problems.The lamp is well tried, reliable and -because it is compact -did not dominatevisually or take up too much room inthe Cathedral. Heat generated is modestand is readily conducted away by fmson the lamp housing. Musicians, thoughalways concerned about any nearbysources of heat, were far less likely tobe put out by CSI than by the sourceswe might have used a few years ago.

Our mains power supply wasdrawn from the National Grid througha main sub-station, near the Cathedral.In the event of failure of the main, thepower would have been restoredimmediately by either of two standbysupplies routed from different parts ofthe Grid system. From the sub-stationthree separate supplies enter theCathedral precincts. We drew about400 amps per phase from a 1500 ampper phase capacity supply near theChoir School on the east side. Anothersimilar supply was. drawn from theChaper House area on the north sideand a third supply from the south side.A major concern ihough, was thepossiblity that a momentary failurewould extinguish the CSI and CIDlamps. To cover this situation, a 130kVA standby generator was separatelycabled to 3 Dino-lights and 9Maxibrutes. Between them theseaccounted for 126kW of lighting -PAR 64's -which would survive mainsfailure-just sufficient to allow picturesto be transmitted if the worst happened.The Maxi-Brutes and Dino-lights hadcolour correctipn ftlters fitted togetherwith specially made glare shields . they

'ENG INF' Autumn 1981 - Page 8

served four purposes: correction oftungsten to CSI; the ftlter was heldneatly and securely away from contactwith the lamps; Side spill light wasavoided, and in case of a "bubble burst"they afforded additional security to thenonnal safety mesh. At all times,electricians had access to generousstocks of chokes and lamps at strategicpoints within the Cathedral.Installation

Electricians started work in theCathedral on 13th July, and had fivenights and two days in which to installall the lighting equipment. Lampsstarted to go in on the 15th. 'Setting'of the lamps took three nights, work ofany nature during the day not being

possible, as the Cathedral remainedopen to the public and nonnal dailyServices right up to Sunday evening -with the Wedding on the Wednesday.

All personnel, including the 130or so BBC staff at the Cathedral on theday, had to be security vetted. Indeedthe heavy security surrounding thepreparations created additionalproblems for us; one was that explosive-sniffmg dogs and their police handlershad to check every piece of equipmentand scaffolding tubing, including ouradditional fire extinguishers, pluswalking round the narrow Triforium atirregular intervals. They could easilyhave knocked the lamps off their settingangle, so that their alignment had to bechecked after each search. However,with close co-operation all round, wejointly and amicably overcame theproblem.

On the day, six electriciansstationed in the Triforium were linkedby portable 2-way radio to a supervisorwho was, in turn, in direct contact withme in the master control vehicle parkedwith other OB technical vehicles in anarea immediately to the north ofSt. Paul's.

After the Wedding we had to actquickly to move some of our camerasimmediately, eight miles of cable and17 tons of lighting equipment out by8.30 a.m. on Friday 31st July, to fit inwith St. Paul's constant programme ofevents and services.

11

Sound AssIstant Penny Kirt checks the microphone performance at St. ClementDanes

'continued from page 8'

THE SOUND STORY

.~~,

;.i:r

Harold Kutscheraurer adjusts amicrophone near the High Altar

Engineers from Radio OutsideBroadcasts rigged 57 microphones tobring the sound of the wedding serviceto the worldwide audience estimated atl,OOOmillion including listeners to BBCand ILR and viewers of BBC and ITV.The sound was fed to a sound controlroom set up in St. Paul's Crypt where a64-channel mixer produced a clean-feedof stereo sound and a second mixed-feed mixer added the commentaries toproduce the feed for Radio 4. BBCTelevision carried out their own soundmixing and other broadcastingorganisations either took directmicrophone feeds or outputs from oneof the mixers.

The needs for producing varioussound recordings had also to beconsidered: BBC Enterprises needed aclean-feed of sound for theircommercial disc and cassette releasedsoon after the wedding, and two digitalrecordings were made, one of clean-feedsound and the other including the Radiocommentary. And as a completelyseparate exercise, a surround-soundrecording was made.

All in all, the whole operation hadthe largest number of stereo OBroutings for any BBC broadcast, for inaddition to the eleven radiocommentary positions along theprocessional route, roving radio linksprovided interviews with the public andsounds of street celebrations created awide spectrum of sound for BBC Radio.

The Royal Wedding

Cathedral's good-natured acoustics andthe use of close mic techniques ensurethat sound levels rarely rise high enoughto excite any troublesome echoes. Thecriteria followed in siting for thisparticular event were:

1. Primarily to provide completecoverage bearing in mind thesound radio presentation. Radiolisteners, lacking any visualcomponent, easily becomeconfused when any of the actioninadvertently wanders beyondmicrophone coverage.

2. To make the microphones lessobtrusive to a television audiencewithout sacrificing sound quality.An example of this was the sitingof the Cathedral Choirmicrophones on either side of theChancel instead of choosing theclassical midway positions. Theblack finish of some of themicrophones helped make themless conspicuous.

3. To provide tighter control ofbalance by the use of spotmicrophones. This gave thetelevision sound mixers the usefuloption of favouring the sounds ofsmall groups of orchestralperformers, for instance, whenthey were being shown in close-upby the cameras.

Virtually all microphones werecapacitor types used in cardioid config-uration and most routed signals down to'continued on page 10'

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'ENC INF' Autumn 1981 - Page 9

Microphone InstallationDetailed engineering planning

began as soon as the weddding wasannounced. Much of the microphoneplacing in the Cathedral was based onpast experience but on this occasion theuse of the Bach Choir and the largeorchestra positioned in the NorthTransept was something more ambitiousthan anything done previously.

Planning the sound in theCathedral was the responsiblity ofSenior Sound Supervisor, HaroldKutscherauer. He arranged coveragearound twenty stereo capacitor micro-phones (mostly coincident pairs), elevenof which were mounted on slings andothers suspended on strengthened cablesfrom the 70 ft high Triforium gallery ofthe Cathedral. The main internal 'soundstages' to be covered were the dais andthe altar for the marriage ceremonyitself, the Cathedral Choir and KnellerHall trumpeters in the Chancel, theState Trumpeters in the WhisperingGallery and by the West Door, theOrchestra and Bach Choir in the NorthTransept, the organ speaking in theNorth-East Quarter Dome and above theWest Door, and the Cathedral Bells. Anexternal stereo pair was suspended fromthe West Portico to catch the West DoorTrumpeters immediately belowsounding their fanfare on the arrival ofLady Diana. The remainingcomplement consisted of spot micro-phones for soloists and sections of theorchestra and choir, and lecternpositions for the ceremonial.

When it comes to siting micro-phones in St. Paul's the problems aremore physical than acoustical. The

Peter Hunt at the controls of the mixing desk

'continued from page 9' The Royal Wedding

Julian Wa/ther sets up the "clean feed" position

the Crypt control room on 20-paircables. Certain key microphones wereindividually cabled as an extraprecaution against a multipair failure.Control and Mixing

In the control room eachmicrophone's signal was fed firstly to asplitter, one output of which was takento the dean feed M-channel mixer, asecond to a 'ceremonial' bay and, in thecase of speech microphones, a furtherfeed was taken to the Cathedral'spublic address system. (A 'Ceremonial'bay is BBC parlance for a type ofmicrophone distribution amplifier usedchiefly on ceremonial occasions whenceit gets its name. Each bay will handlenine microphone inputs and each inputhas two buffered outputs.) The outputsof the 'ceremonial' bays provided bothdirect microphone signals, for example,for BBC Television and ThamesTelevision, or in other cases, a mixedfeed, for example to BroadcastingHouse for the Radio Network.

For large ceremonies it "isnormalpractice in BBC Radio for two mixersto be installed where possible. Themixers are used in adjacent butacoustically isolated rooms as they wereon this occasion in the Crypt. Thisisolation enabled the mixer at the 'cleanfeed' desk to concentrate more fully onbalancing the ceremonial. The 'cleanfeed' desk output was then fed to the'mixed feed' position where theoperator mixed the commentators'microphones using cues from talkback.Recording the Wedding

An occasion as sonically grand asthis one also gave the impetus to maketwo extra forms of sound recording over

'ENC INF' Autumn 1981 - Page 10

and above the standard analogue ones.In the first instance two digital

recordings were made, one of clean feedsound carried out in the digitalrecording van parked in the CathedralChurchyard, the other of mixed feedsound, undertaken at BH.

The digital van was equipped withtwin video recorders with a 16-bit pulse-code-modulation unit plus the normalsound monitoring and mixing facilities.Previous problems with tape drop-outs,more noticeable in digital recording, arenow largely overcome by ensuring adust-free recording area and using onlyhighest quality pen-tested recordingtape.

Finally the surround soundrecording project was undertaken by OB

Engineers as a technical experime~t toaid British industry. Four sound-fieldmicrophones of an improved designwere specially loaned for the event,three being used internally in theCathedral to cover the Chancel, NorthTransept and the Nave towards the WestDoor. The fourth was mounted nearthe Cathedral steps in the N.W. Lantern.The four component outputs from eachmicrophone were separately assignedto individual tracks of a 24-trackrecorder without any form of surround-sound coding. The use of special noisereduction devices was planned, butinterference from nearby thyristorlighting dimmers ruled out their useand, instead, a higher tape speed of30 Lp.s. was used to improvesignal/noise ratio. A problem then arosewith sound linking on tape changeoverssince at this high speed each reel of taperan for only 30 minutes. This was over-come by arranging changovers to occurduring pauses in the wedding service or,at least, on non-musical items, andfurther arranging for a standby two-channel recorder to make a linkingrecording in stereo. These stereorecordings would then suffice in anysubsequent System HI matrixing tobridge the gaps in the multichannelsurround-sound recording.

Setting the sound-fieldmicrophones was relatively simple: eachunit's four encapsulated microphonescombined with a matrix processor gavethe system a unique versatility enablingan extremely wide range of operatingmodes to be electronically selected. Inthe Cathedral each sound-fieldmicrophone's physical height was set'continued on page 12'

Dennis Yee in the digital sound recording vehicle

Satellite Terminal made by RD

The"vehicle and trailer ready for the road

The mobile satellite link tenninalcommissioned for Television OutsideBroadcasts has just been completed byResearch Department, and is undergoingpre-operational trials prior toprogramme commitments starting nextmonth. .

Use of a satellite to get televisionsignals back to Television Centre willenable the tv service to mount OBswhich cannot easily be covered byconventional means. The principle wassuccessful demonstrated on 7 June 1980on a live tv OB from Glencoe when theBBC hired a satellite tenninal as anexperiment. The main terrestrial routerequired seven radio link hops to be setup.

However, a more stream-linedand versatile satellite tenninal wasdesirable to fit in with the futureOB operational arrangements. Ateam was set up at ResearchDepartment under the leadership ofMalcolm Hannan to design andconstruct suitable equipment using thelatest technology. Much expertise hadalready been gained from the designand construction of a smallexperimental satellite receiving stationat Kingswood Warren for experimentswith OTS.

A particular feature of the newtenninal is its compact size, such thatthe complete transmitter is housed on arelatively light-weight trailer which maybe couple to any standard radio-linksvan. This has been achieved by usingthe latest transmitter technology" and

housed in 3 equipment boxes which fitinto the multiplex shelving bays in thelink van. Thus, once the transmitter hasbeen set up and the satellite initiallyaccessed, the operation is completelycontrolled from the link van.

The transmitter is very flexibleand may operate on any of the availablechannels through the OTS or futureECS satellites. It uses a new ThompsonCSF 600W TWT (travelling wave tube)in the output amplifier, which has beenthe key in achieving flexibility, compactsize and conservative single-phase powerrequirements. In practice there are twosuch amplifiers arranged in dual-redundant mode so that negligible breakin transmission will occur should oneamplifier fail in service. The amplifierswere specially made for this project byEMI Varian and Malcolm Hannanrecently spent an anxious period at theirfactory in Santa Clara, USA to see thatthe units were completed in time.

Work on the project began about

~~

mlJ1f.J aJ

'Project manager Malcolm Harman (right) checks for radiation hazards aroundthe periphery of the transmitting dish during acceptance tests at KingwoodWarren, with (from left to right) Trevor Denham (TVOBs), Derek Hodge andChris Candy (satellite team, RD)'.

represents a significant advance overprevious mobile satellite terminals. Thetrailer houses the 3m dish aerial, 600W14 GHz transmitters, check receivers,f.m. modem and other associatedequipment special to the satellite link.The trailer may be remoted up to 400 ftaway from the link van to ensure that aclear line-of-sight path to the satellitecan be achieved, and it can also be keptclear of the OB ~ontrol area.

Baseband video and audiointerfaces and all the transmitter remotecontrol and monitoring equipment are

18 months ago and completion has beenspecially brougllt forward to meetprogranlIDe requirements of theTelevision Service. It is thanks to thedetennination and enthusiasm of theteam and the support they receivedfrom Technical Services that thetenninal has been completed on timedespite delays experienced in the supplyof major components frommanufacturers.

* **'ENC INF' Autumn 1981 - Page 11

'continued from page 10'

by listening to the output of a 'unit inomnidirectional mode, and fIxing theheight when the most satisfactorybalance was heard. A height in therange 30-50 ft proved about right.Royal Success

And so, for such a complexexercise as the Royal Wedding and onerequiring high reliability with 1,000million pairs of ears listening for themarriage vows, how did the wholesystem perform?

Well, very successfully - it could

hardly have been otherwise, but bearingin mind that much of the ceremonycould not be properly rehearsed, thequiet sighs of relief from the engineersat the successful conclusion could bewell understood.

The introduction of television andits accompanying lighting into a large,completely 'wired-for-sound' cathedralcertainly presented numerous humproblems, for instance. But after thebelow-par cable screening was trackeddown and some cable re-routing under-taken, the 7 miles of microphone cableand the la-mile long lighting networkco-existed successfully, each in its ownway making a vital contribution toBritain's and the World's biggest O.B.IN-VISION SUBTITLES

No fewer than four captiongenerators were used to provide thein-vision subtitles for the RoyalW~dding on BBC 2. Two wereassociated with the material preparedbefore the broadcast, and two otherswere connected to main and reservePalantype transcription computers togive a verbatim transcription ofTom Fleming's commentary. Becausethis was a rather special event, thesubtitles were available for all to seerather than being transmitted throughthe CEEFAX magazine computer aswould normally be the case.

The experimental Palantypetranscription system is the result of acollaboration between DesignsDepartment and Leicester Polytechnicwhere Lyndon Thomas,. a computerscientist, has been writing the variouscomputer programs.

Last year whilst on attachment toDesigns Department he made thetranscription program run on asophisticated micro-computer for thefirst time; and since then the equip-ment has been made suitable for theCEEFAX broadcasting chain.

On the Royal Wedding day thesystem worked as follows: thePalantypist keyed the speech phone-tically into a special keyboard, syllable

The Royal Weddingby syllable; the keyboard output wasfed to the transcription computer whichmatched the syllables to the contentsof a. dictionary held in store on aWinchester hard disk memory. As eachcomplete word was found, it was passedto a small output formatting micro-computer which assembled the wordsinto lines of text and passed them to acharacter generator.

Up to the last moment, RonSpencer of Designs Department, andLyndon Thomas of LeicesterPolytechnic were in close contact overthe major up-date of the dictionary heldin the Palantype transcriptioncomputer. For such was the scale ofthis up-date that a completely newdictionary had to be prepared using thelarge campus computer at LeicesterPolytechnic; this meant that rehearsalfor the programme could only begin onthe Monday two days before the event.

The three Palantypists chosen forthis work had spent some timerehearsing . on their mechanicalkeyboards, with audio tapes ofTom Fleming's previous commentariesbut now they could try out their keystrokes using the computer in its fmalform and rehearse changeovers every tenminutes or so, to cover the events for anhour before and after the WeddingService in St. Paul's. In the event, therate of speech was much faster than theaudio tapes had suggested and this,coupled with the atmosphere of a veryspecial occasion, caused the error rate tobe fairly high. In their normal work thePalantypists can easily correct theseerrors, and so provide accuratetranscription from their subsequenttyping of their shorthand records.Real-time verbatim transcription offersno such second chance; the subtitleshave to go out as they are. Neverthelessthe response from many deaf peoplewas one of gratitude, encouraging, andat times moving.

Mike Cathawood, the producer ofthe subtitled programme, handled themixture of old and new techniques in atruly imaginative fashion, and thePalantype team were grateful for theway he researched the subject, givingthe information that was required tomake the most of the subtitles offered.Moreover there was excellent supportfrom the Network Engineers on duty inSub-Control Room in Television Centre.

The other people worked veryhard to make the operation a success.Pearl Martelly typed in the twentythousand or so entries for the newcomputer dictionary. Peter

SommerfIeld, another member of theDesigns Department team, supervisedthe two word-processing micro-computers that Pearl used, as well asensuring that all the hardware wasmanufactured in time.

There are many aspects of theverbatim transcription of speech byPalantype which will have to beunderstood before it becomes clear towhat extent the techniques can be usedin broadcasting. For the moment,probably the two most importantproblems to be solved are the trainingand acclimatisation of Palantypists tobroadcasting. It is hoped to give thePalantypists more practice by using aspecial commentator for the deaf, sothat a reduced rate of speaking can beused. Moreover it will give the audiencea better chance to read the subtitles andresearch may show this to be a veryimportant consideration.

It is possible that a somewhatlarger, more versatile and error-correcting transcription computer willhave to be provided, but the resourcesrequired for this development can onlybe justifIed by the results obtained fromexisting equipment. Meanwhile muchremains to be done if one day we are toprovide the kind of service for the deafthat hearing viewers already enjoy.

Certainly the results from theverbatim system were not as good asthose suggested by the tests that hadpreviously been carried out, and at fIrstthere was an air' of disappointment thatthe programme did not demonstrate thebreakthrough that everyone had workedfor. But to reassure both the engineersand palantype team, what was neededwas not the opinion of those who enjoythe output of three television networksday by day, but the opinion of thosewho cannot hear. As far as we canjudge their verdict comes to the BBC asan overwhelming ''Thank You".

'ENC INF' Autumn 1981 - Page 12 Published by BBC Engineering Information Department, and printed by Print Unit, ETD, Wood Norton