February 2019
The Trust was formed last year in order to save and preserve broadcast television equipment, and also to engage, particularly  young people, in the technology which has enabled millions of people, during the twentieth century, to watch television programmes in the comfort of their own homes.

You may already know that our first project is to restore ex-BBC MCR21.  The Trust have  already received  £10,000 from the Heritage Lottery Fund. which included money to set up the Trust and draw up a restoration plan. The Trust have now submitted the second application for a HLF grant to fund restoration of MCR21 and tell its story. We are keeping our fingers crossed and hope to announce, in the next newsletter, that we have been awarded the £100,000 needed to carryout the work. We expect the decision will be made in March.

If you would prefer not to receive our newsletter, please tick the unsubscribe box at the bottom of the page.

Why it is important to save and restore MCR21

by John Trenouth

1) From the 1930s through to the 1980s Britain was at the cutting edge of television technology and programme making. Although a good representative collection of this uniquely British technological heritage does exist (in the Science Museum & in the care of passionate collectors), to the future researcher & student, the way in which these disparate items worked together is harder to understand. However a Mobile Control Room effectively contextualises the interrelationships and interconnections of all this complex technology. In the same way that a medical student may carry out intensive study of the human heart, taken in isolation without seeing its relationship to the whole body renders much of the study useless and incomprehensible. There are extant some examples of later Colour Mobile Control Rooms, one in the Science museum collections (although for some inexplicablereason they disposed of a second, more recent one). However MCR21 is the earliest surviving UK example of the earlier monochrome units.

2) There is a timescale imperative to save this example. The restoration falls into two discrete areas; firstly repair & renovation of the vehicle and secondly the repair & restoration of the electronic equipment within.

Repair & renovation of the vehicle: After 55 years, rust & corrosion to the vehicle body along with mechanical defects have taken their toll. The point is approaching when renovation will become extremely problematic and hugely expensive. At the moment it is possible to save the vast bulk of the vehicle in its original form, in another 10 years without this intervention it may well be impossible to do so.

Restoration of the electronic equipment:
The Australian MCR restoration faltered & eventually stopped because the champion of that work, Barry Lambert, was unable to locate enough people around Melbourne with the necessary skills, knowledge & experience to support him. He ultimately travelled halfway round the world to the National Museum of Photography, Film & Television in Bradford to seek help. We were able to help him with information and spare parts as well as putting him in touch with retired engineers in the UK who had worked with this type of equipment.

Fortunately there is a much larger pool of people (& in a much smaller geographical area) in the UK who are familiar with this type of technology - in the case of MCR21 much of it is hybrid electronics, using valve technology alongside early germanium transistors. However the people who worked with equipment of this era are now into their 70s and sadly this store of knowledge is dwindling year on year, so we either save MCR21 now or risk losing it forever. Unlike the vehicle body & mechanical work, it is not possible to outsource the electronic restoration.


The Trust has received support from  important organisations. The Science Museum Group, Amberley Museum, the British Motor Museum, CTV OBs, Megahertz Ltd, Royal Holloway University of London, the British Entertainment History Project and the BBC. This is an extract from a letter written by Lord Hall, Director General of the BBC.

I am very happy to support The Broadcast Television Technology Trust's important project to restore the MCR21. Broadcasting can seem such an ephemeral art, so these iconic technological artefacts- such as the MCR21-are key for all of us who work in the field of broadcasting, and in particular our close colleagues in conservation and interpretation.
The MCR21captured major moments still in our living history-the1963 Grand Prix, the 1965 funeral of Winston Churchill, and seminally, the 1966 WorldCup. It also was part of the transition story from black and white to colour television.
For these reasons I am keen to see your project reach fruition. An MCR21 completely restored and accessible for museum display and wider events would help our audiences understand the swiftly changing world of broadcasting and how it crystallises many of our national memories.

Tony Hall, September 2018

Preserving our Technical Heritage                          
 by Brian Summers 

Great Britain has a long history of leading the world in technological progress and there are many great examples that have been saved for the nations future. Steam engines, ships, canals, vintage cars and buses, theatres, even submarines, it's a long list but there is one glaring omission. We have no examples of a preserved Television Studio!
Alexandra Palace was the birthplace of the BBC's then high definition service on 405 lines.  The studio buildings survive, but despite a number of attempts to restore them, they remain a decaying empty shell with little trace of the original studio installation left. If the funds could be found the building could be saved but it is too late for the original technical equipment which, with the exception of a few cameras in other museums, nothing is left to preserve.
Whilst it is too late to save the many Television Studios that have been used, destroyed and sold, think of   the BBC's Television Centre, Lime Grove, the many ITV franchise studios, Anglia, Tyne Tees, Granada, Thames at Teddington, it's a long list.
Fortunately it is not too late to save an example of a BBC outside broadcast vehicle. Built in 1963 the BBC's MCR21 is the oldest and most complete “OB” van. It was built by Pye of Cambridge to an exacting BBC specification and represents the culmination of a quarter century of progress in the arts of television technology. 
Ten of these were built to be the backbone of the BBC's fleet of outside broadcast vehicles. Their output would have been on the TV screens of the nation from the moment they were built until the advent of colour television. MCR21 is known to have televised many important national events, like the 1964 Grand Prix, the 1966 Cup Final, Winston Churchill's funeral.
Technically MCR21 incorporated many firsts in the use of new electronic devices and methods:- Extensive use of transistors which replaced many valves improving reliability and reducing power consumption.  A few key items:-  

The BBC designed 10 channel vision mixer is an example of this. It used diodes for switching in the vision mixer, enabling for the first time “Cut in Blanking” and special effects for the first time in an outside broadcast van.  The basic design of this advanced vision mixer was used in later colour studios and vehicles for nearly two decades. 

The all solid state 20 channel Sound mixer, designed by Pye, was advanced for its time and featured for the first time “battery backup” so that in the event of a power failure, the program could continue in sound only.
Two miniaturised SPGs, Sync Pulse Generators, again transistorised for the first time, made by Ferguson were installed. These could be changed to operate on the old British 405 line system, or on the American 525 line system, or the new 625 line system when it first started to be used on BBC 2 in the UK on the new UHF system. 
The BBC's MCR21 OB Van incorporated equipment made by many famous British manufacturers:-
Commer (the vehicle), Marshall (coach building) Pye Television (main equipment and installation), Ferguson (Thorn), English Electric, BBC equipment department, Reslo (microphones), TMC (telephones), Peto Scott, Claud Lyons, Haybeard, Vortexion, Eddystone, BICC, Crabtree, Belling lee, Exide and Tektronix(USA) Philips (Holland).
Preserving Technology

Technology isn't just about preserving equipment, for the Broadcast Television Technology Trust, it is also about recording and preserving the knowledge of how the technology was developed and used. In parallel with the display of MCR21, there will be a website where the technology of MCR21 will be explained in detail. As the BTTT expands, more information will be online about all aspects relating to broadcast television.

Below is an article published in 1949 by H Hopkins who designed a very early zoom lens for W Watsons and Sons
ZOOM LENSES     by H H Hopkins                           Wirelees World 1949

A recent innovation in television outside broadcasts has been  the introduction  of  a zoom  lens, which is an attachment for converting any ordinary fixed-focus camera lens into a lens of continuously variable focal length. The new lens has been made by. Watson and Sons, of Barnet, and was used for the first time at the televising of the Cup Final at Wembley this year
The zoom lens is mounted on the front of the television camera and is operated by rotating  an outer cylinder which imparts axial movements to the two inner component lenses, 2 and 3, by means of cam slots, the outer components, 1 and 4, remaining stationary. If suitable movements are given to 2 and 3,  the final image remains in focus on the photo-cathode of the television camera, and the  focal length of the combined optical system varies. The result is that the size of details in  the picture is altered, creating  the  illusion that the camera is moving towards or away from the  scene.  The zoom lens at present being used for television, enables the image  of any detail in the scene to be varied over a range of  4 : 1 in area, and it will work in conjunction with any camera lens having a front  diameter no greater  than  2 in  and   covering an angle of field that is not more than 30 degrees. During zooming, the relative aperture of the combined optical system remains constant, and consequently the brightness of the image also remains constant. The aberrations of the system are corrected by balancing the positive and negative aberrations contributed by the different surfaces. 
Any change in the relative positions of the component lenses will, in general upset this balance, and so it is necessary to a  minimum,  the   movements of the inner components 2 and 3. The conditions that result in minimum movement have been worked out and are satisfied by the lens. In addition, the optical conditions resulting from the refractions by the moving components have been studied and a relatively simple mathematical treatment for calculating them has been worked out. This treatment reveals the conditions that must be fulfilled if a satisfactory lens is to be produced,  taking into account the inaccuracies, small but optically significant, that  are  unavoidable  in  the  best available non-geometric cams. Zoom lenses have previously been very complicated. Simplicity is one of the principal factors contributing to the success of the new lens, which has only four components and yet gives excellent definition. Furthermore, this economy of components results in· a greater efficiency of light transmission and also in the elimination of stray light, compared with certain other zoom lenses
You can have a look at  MCR21 in its present state by watching a video where Brian Summers shows you around the unit.
We are looking for help with the MCR21 Project. While the Project is based in Surrey, there are many tasks that can be carried out  in other parts of the UK.. So please do get in touch - either by email. If you know someone who would like to receive our newsletter, please send their email address to Nick or Brian or - I would very much like to hear from you so, if you prefer, do give me a call.  Nick Gilbey
Tel 07831 219957

our website is
Copyright © February 2019  Broadcast Television Technology Trust, All rights reserved.

Want to change how you receive these emails?
You can update your preferences or unsubscribe from this list.


This email was sent to <<Email Address>>
why did I get this?    unsubscribe from this list    update subscription preferences
MCR21 · The Abbots House · The Street · Charmouth, Dorset DT6 6QF · United Kingdom

Email Marketing Powered by Mailchimp