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Designs Department - Reminiscences

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Third time lucky – how I came to join Designs Department
by David Birt

My earliest awakenings to electronics were very similar to those of my colleague Neale Davison which he describes elsewhere in this reminiscences section. Certainly I appreciated the magic of “wireless” at a very early age. Indeed, by the age of 4 I had made myself a toy “wireless” by appropriating a wooden box on which I drew knobs, a dial, a ‘speaker grill, and even a tuning indicator – all coloured-in with crayons – and it had a string mains lead! I can date this by the year in which my family moved house. That box survived for decades!

As with Neale, “Childrens’ Hour” and in particular “Toytown” were much enjoyed, and had a profound influence on me. I used to enjoy it when David (I think it was) used to fill-in by playing the piano, and I admired “Mr Inventor” to the extent that I concluded that it would be rather good to be an inventor when I grew up! In a small way, I suppose that came to be. For me, the supreme magic of wireless was that it produced music, and after the ubiquitous 1-valve receiver which I eventually got working on Palm Sunday 1946 (aged12), the following year’s project was what we would now call a hi-fi amplifier. I still have it, though only the power supply (or power supplier as the BBC would have it) is in use – to drive an FM tuner –  which I built whilst I was at college.

At boarding school, I soon established a flourishing radio repair business, did various public address jobs, and during the holidays I spent most of my time assisting in the workshop of the radio shop local to my home. It was there that I saw my first television pictures on pre-war receivers which were being resurrected in time for the 1948 Olympics. Some of these used electrostatic deflection, and what lethal devices they were! I soon learned that dielectric strain in the capacitors of the day would cause them to acquire a charge of several joules at several kV sometime after they had been discharged with a screwdriver! I consider myself very lucky that by the time I came to leave school, I knew exactly what I wanted to do.

The first attempt

Accordingly, whilst still at school, I wrote to the then Chief Engineer, BBC (Harold Bishop) enquiring whether the BBC could offer me any training or apprenticeship schemes. Somewhat surprisingly, the answer was no: words to the effect “go ye away and get ye an hons. degree, and then we might be willing to talk to you”. So that didn’t work! In the event, I began an HNC course at what was then the Regent Street Poly., just across the road from the hallowed portals of BH.

Once I had started at the Poly., it dawned on me that I would be spending 4 years learning all about steel production, Bessemer converters, foundry technology, and turbines, but would only be spending one term on the very basic rudimentary principles of electronics (which I already knew). So I swapped horses, and signed-up for a 3-year sandwich course at the EMI College of Electronics. After that, the next part of my 32-year-long and rather tortuous journey to the BBC took me through the jungle of National Service in the Army, where I ended up at the REME Radar School at Arborfield (near Reading) as an Instructor. When I did eventually join Designs Department I met a contemporary fellow ex-Sergeant from that establishment.

You may care to follow the links to

During a weekend leave at the time when my demob. chart was almost fully filled in, (1956) I was pottering round the back lanes of Surrey, and came across this mysterious unmarked building in the grounds of which stood a 3Mk7 radar set!

Enquiries revealed that this was Mullard Research Laboratories. Deducing that some radar work must go on there, I wrote-in to the effect “I know a bit about radar,g’us a job”. There was indeed a radar lab there, and an Army 3mk7 set was being converted from 10cm to 3cm. The upshot was that I joined the television lab.! It was here that I was to have my first contact with BBC engineers from nearby Kingswood Warren.

If you would like to read about life outside the BBC at that time, what was happening at the “receiving end” in domestic TV receivers, and about the experimental NTSC 405-line colour transmissions from that perspective, please go to the link So near and yet so far.

The second attempt

By early 1963, I had designed and built a couple of switch-mode “Class D” audio amplifiers, and aired some ideas on the topic in an article “Modulated Pulse A.F. Amplifiers” in Wireless World (February 1963). This was all private “homework”, and publication was only allowed provided that there would be no hint of any association with Mullard/ Philips. The company feared the new technology greatly first, because it wasn’t able to produce fast-switching power transistors, (given the germanium technology it had adopted,) and secondly, it worried that existing “class B” audio customers would be upset, and their businesses damaged. In fact it took many years for class D technology to be developed commercially, and for it to be generally accepted for high quality audio. The arrival of power field effect transistors (FETs) c.1979 made the concept all the more attractive. As a point of interest, the amplifiers for the sound system in the Millennium Dome were class D, and were designed by my friend Chris Newey: a former member of RF Section in Western House in the 1980s.

Back in 1963, I had also conducted some listening tests to try to establish the audibility of alias distortion in class D and other sampled audio systems. Just the sort of thing the BBC might also be doing regarding the use of PCM? I had also been working on television receiver techniques for 7 years.

So when, later that same year, I spotted advertisements for two jobs going at Kingswood Warren: one sound, and one video, I applied for both!

When I arrived for the interview, I was ushered though the heavy oak door into this splendid panelled room. There were to be seen 17 small desks, each equipped with water jug, glass, and notepad. The desks were arranged in a parabola. At the point-of-focus of the parabola a “Mastermind”-type chair had been placed, and that was where I was invited to sit. Behind each of the desks sat an interviewer, and a blackboard and easel had been placed to one side. Questions were fired at me for the next four and a quarter hours! At the conclusion of this intimidating ordeal I was ushered out by the Research Executive who said to me: “ Officially I can’t say anything, but unofficially I think you weathered the storm quite well. If you have been successful we will write to you, and you will be required to attend a second interview which will be in London, and will be non-technical. You will have to see the Civil Service Commissioners, and they will want to know if you have been in prison, or anything else like that – ha-ha-ha”.

Fortuitously, I then took some pre-planned holiday, and on my return there was a letter inviting me to an interview at The Langham. So I went along whistling, and with a spring in my step. I knocked on the nondescript door on the n-th floor, and on entering found myself at the end of a long table at which sat the same 17 interviewers. They all rotated synchronously in their chairs to look at me, and proceeded to ask me those questions which I couldn’t answer satisfactorily at the previous interview. Presumably this was to see if I had done my homework. Having been on holiday I had not, and I was unable still to “define what is meant by directivity index”, for example. I felt stunned, and cannot remember quite how the interview ended. I never heard another word from the BBC. Oh dear, it just wasn’t going to happen was it – or so I thought at the time. However, as you will see below, I was to return to that panelled room 18 years later.

In the event, I left Mullard’s and went to work for Redifon Telecommunications in Crawley, where I designed a whole lot of HF communications equipment. I kept an eye out for opportunities to develop my interest in class D, and it wasn’t too difficult to persuade management of the benefits of switch-mode power suppliers, probably because other manufacturers were already making and using them.

Transmitters, and pals at the BBC

The suggestion that we could replace our old valve-based G142 NDB beacon transmitter (50 Watts at 400-600kHz) with a class D solid-state product met with the predictable fierce opposition. However for my next design of switch-mode power supplier, I decided upon a 600kHz switching frequency. This was partly for good technical reasons, but there was an ulterior motive! It was then a trivial matter to demonstrate a 100W, 600kHz class D transmitter. Two TO5 cased output transistors on a heatsink the size of a cigarette packet which got barely warm! The response of senior management could be described as "digital" : it went from all ‘0’s to all ‘1’s in a matter of microseconds! The Civil Aviation Authority in Iceland was promised the prototype of the new BK125 navigation beacon in 3 months time! Yes, a lot of midnight oil for rather more than our MD’s over-optimistic estimate of 3 months, but a fascinating trip to Iceland at the end.

Transmitters and pals at the BBC  -  BK125 in Iceland

After the beacons had gone into production our Managing Director died, and the company went into the doldrums for a time. Redifon had manufactured broadcast transmitters in the past, and I saw the possibility of extending the beacon technology to the MF broadcast band: upwards in frequency to 2MHz, and in power to 1kW carrier (5kW PEP for the Americans who like 125% modulation because it sounds awful loud). This “planted seed” did not germinate. However, I did manage to obtain permission to attend an IBC exhibition at the Dorchester. I was riled to find an American 1kW solid-state (though not class D) MF transmitter on show. 

Close encounters

This American transmitter was being closely examined by a number of people whose name badges indicated they were “BBC”. I surreptitiously noted down their names, and passed these to my one ally in our sales department. The upshot was that we were invited to tender for supplying the 1kW transmitters for the MF network changes of 1978, and we won the contract. That gave us 20 months from “back of envelope sketches” and un-proven ideas to the delivery of 25 transmitters. Apart from the fact that these were all class D (with RF power amplifier modules that achieved 93% efficiency), we broke new ground by moving away from the traditional main / reserve concept and using a fault-tolerant topology whereby even if one third of the transmitter failed, you would only loose 1dB of output power. And look: no fans!

During these 20 months, I met with BBC Transmitter Capital Projects engineers on a more or less weekly basis, and thus made new friends. Even DE (Jim Redmond) came down to see how we were getting on. When it came to field trials and installation, I worked together with BBC engineers on site. It almost felt as though I had joined the BBC. I spent the night of November 23rd 1978 at the Londonderry station. Not a place I would wish to visit again, but it was a bit of a buzz to get back to our lodgings for an Irish breakfast and listen to “our” radio broadcast from the new transmitter.

Two Redifon BT1000 MF broadcast transmitters at Whitehaven,
showing one of the modulator output modules removed

Dark clouds with a golden lining

Back at Redifon, there was yet another change of top management, and the new MD (a former Sales  Director who had been booted out of the company in short order by the previous MD who had died) declared “Oh we don’t want to be involved in broadcasting” (even though broadcasting products accounted for the majority of the company’s turnover at that time). Clearly this placed me in an untenable position, especially as I had been told that ways would be found to get rid of me, and that I need not think I was protected by legislation. The prospect of finding another job at the age of 47 was a bit scarey! My new friends in TCPD were aware of my predicament, and I am eternally grateful to one who ‘phoned me to say “It might be worth buying next Thursday’s Telegraph”. Behold, there was an advertisement for Design Engineers to join Designs Department.

  Advert in Daily Telegraph

 The third attempt

The “come and see us and have a look round” interview was arranged quite quickly, and I thoroughly enjoyed it. The more formal board followed soon afterwards. I opened the conversation by saying that I hoped this wasn’t going to be like my previous KW interview (described above)! Everyone chuckled – “no we are all reasonable people” – as indeed they were: very much so. Ian Miller, David Kitson, Johnny Johnstone, and a man from personnel. There were some thought-provoking questions such as “why 75kHz deviation on FM? Suppose we wanted to improve the quality, could we do this by increasing the deviation?” This was not something I had ever thought about in detail, however the questioner “shone a torch on the path” to guide me to an agreed conclusion that 75kHz represented a kind of broad optimum figure. When asked how many bits were needed to code 625-line pictures, my response was “I’m skating on thin ice here!”  “Well skate around a bit !” “10?”  “well actually 8 will do”. So it was a friendly and indeed enjoyable interview with no sense of the panel vying with each other as to who could ask the most tricky questions, or who could best tease out and amplify my weaknesses.

Afterwards, there was a period of anxious waiting, and then I received a letter asking me to go and see someone from personnel. Worrying! What this was all about was that it would be “convenient” (though not necessarily essential) if I would consider becoming a member of the IEE (C.Eng.MIEE). In my circumstances this meant submitting a thesis, and attending a board at the IEE in Savoy Place as a mature candidate. It may be thought that the fountain outside the IEE building is decorative, but it has another function (given a wind in the right direction) which is to absolutely drench a prospective candidate as he walks up the steps – take him down a peg? However, the interview went just fine, and so the final hurdle was jumped.

When my contract of employment arrived, it was pretty strong stuff! It read along the lines of “If your verk iss not to tzee satisfaction of tzee Commandant, you vill be shot”, But in with this was enclosed another letter, explaining / apologising for the tone of the contract which had been determined by employment legislation.

My first day  -  “home” at last!

Since I was to join Transmission Section, I went first to see John O’Clarey who was section head at the time. He took me on a tour of Western House at ‘lightning’ speed, and I had almost to run to keep up with him. The tour finished at Room 504 which was the office I would be sharing with six others: Alan English, Alan Rowe, Rhys Lewis, Owen Cullum, John Robinson, and Robin Caine. Did you know there is a ‘40s song “Room Five Hundred and Four”? By odd coincidence, as I write this piece, it is being broadcast on BBC Southern Counties Radio. There certainly was a song in my heart at the end of my first day! In the beginning, I used to make the last 10 miles of the journey by train/ tube. On my way home I remember standing in the tube train displaying with maximum prominence the largest of the buff internal-mail envelopes with ‘BBC’ writ large upon it, and feeling immense pride that I was now part of that organisation. This was the beginning of what was without doubt the happiest period of my working life. I had not worked in an environment where engineers were respected to that degree before. Nor had I encountered Managers of such integrity. Nor had I worked amongst such a large body of excellent engineers, technicians, and support staff who were not only of the highest calibre, but delightful people as well. I consider myself most fortunate to have been able to enjoy a period pre-“Black Spot” when the BBC was such a happy and productive place to work. For a time, it was still enjoyable post-“Black Spot”, but the sun had gone beyond the horizon. As you will see, my first project - 68PAL -  was one which was shared between Research Department (which had conceived the idea), and Designs Department (which helped to develope it, build it, and make it work). So it was not long before I found myself at Kingswood Warren. I determined to find the infamous “panelled room” last visited 18 years ago, which was by now the canteen. Once inside the room (and making sure nobody was about) I let out the biggest ”raspberry” I could muster!

Please follow the link to the early days of digital for details of 68 PAL

Life in Western House

To begin to amplify what I have written above, I think the key words are mutual trust and respect, support, and also efficiency.

As you may have gleaned from my earlier comments, I had found in industry something of a culture of mistrust. Engineers were useful to have “on tap”, as long as they weren’t “on top”, and were reminded of their lowly station. Let me give an example. There was a period at Redifon when, if you needed a new bit for your soldering iron, you had to send the old one back to the main factory stores in London, with an application for its replacement. Management did not allow soldering iron bits to be kept in the local R&D lab stores in Crawley – lest people might take them home for their own use! For the administration cost of this absurd bureaucracy, everyone could have been given a dozen free bits a year specifically for their own use!


Still on the subject of stores, mention must be made of the excellent stores staff in Western House. This adds efficiency to the word support: they were so knowledgeable and helpful. Moreover, this was the first time I had encountered a stores system where you actually knew the cost of the items you booked out.

Then there was valve stores at Motspur Park: again amazingly knowledgeable about a huge range of semiconductors, and so helpful.

Looking back over a period of 23 years brings changes into sharp relief! In the morning, one was greeted by Reg (?) the resident Commissioneer who always exuded great bonhomie, and was immensely proud to be associated with what he described as the absolute cream of engineering. He doubled as lift driver. There was also a DIY service lift, and I had a mildly embarrassing experience with that during my first week. Having pressed the button, I rested my hand on the gate handle in anticipation of the lift’s arrival. I did not appreciate that once the interlocks had cleared it took only a fraction of Newton force to open the gate. Consequently, when the occupied lift approached, the gate flew open stopping the lift. There followed a tirade (resembling the barking of an Alsatian in the presence of an intruder) from a senior member of staff, regarding people who hijacked the lift instead of waiting. I didn’t mean to do it – honest!


Then, the numerous BBC canteens were thought of as a facility for staff, rather than a money-making enterprise. The tea bar on the top floor of Western House was popular. For something more substantial at lunchtime there was a wide choice. Across the road in BH, there was the 8th floor restaurant, the 7th floor snack bar/roof garden, and the basement restaurant near the concert hall. Just up Gt. Portland St. there was another canteen at Yalding House where the music library was housed. Charlotte Street, and Marylebone High St. were within easy walking distance. There was also the club restaurant in the Langham. In the evening, one could get a really nice meal at a very reasonable cost in BH, and quite frequently I used to arrange to meet friends there e.g. before going on to a concert. Even without non-BBC friends, I used to patronise this a lot. I remember a chap – retired painter/decorator I think he was. May be he had once done some work for the BBC? I can’t remember his name, but he lived somewhere in nearby Hallam Street, and he used to enjoy the food and our company. I am sure he didn’t have a pass, but everyone knew him so that was OK.

Popular lunchtime destinations were John Lewis (for DIY materials) and of course Proop’s in Tottenham Court Road. I expect many of us still have various interesting bargains which were bound to come in useful for something, sometime? I still use the excellent digital multimeter I bought there for £20.


Time sheets consisted of a single sheet of A4 pinned up in the lab – just tick the boxes! It was usual to book a half, or even occasionally a full day to admin. That would have catered for the occasional lab tidy-up where we would all muck in with bucket and Jaycloth, and even polish. This was often the occasion to stack up stuff to send to redundant plant. This was usually piled up on the floor, but to be fair, it did sometimes stray onto an adjacent bench. Unfortunately, there was one occasion when a brand-new, expensive spectrum analyser (I think it was) was adjacent to the junk, and it went in the crusher too. Oh dear!

Admin would have covered time spent in the library, which was yet another very useful resource. We had a lab. secretary who relieved us of much of the admin., and who typed-up our hand-written letters/memos/documents. The VAX1 computer was operational (except at times in the hot weather – sorry John!), but word-processing was something of a minority activity.

Flex time

This was a new thing for me, and I class it as another example of support. Excellent! The ability to time my journey so as to miss the “school-run” rush, and to align better with my personal owl-like metabolism was a boon. That extra day tacked on to one weekend per month made such a difference.

Technical standards in the BBC

There was a good IEC- standard listening room in Western House. One day there assembled there a gathering of top brass, and a few “golden ears”. This was in response to a listener’s complaint about a short (2s?) break in a concert which had gone out on R3. Recordings were played, and you could say all Hell was let loose! A very thorough investigation followed, and I was greatly impressed by the seriousness with which listeners’ complaints were taken.

Broadcast sound was the doyen of the highest of fidelity up to the early 80s, when the Compact Disc arrived.

Some things we didn’t have

We didn’t have cash machines, but there was a “bank” on the ground floor of BH.

Few had their own personal computer, and if they did, it was a Beeb micro perhaps, and memories were in general measured in kBytes. We did not have

e-mail or the internet.

Flexible work.

Now here’s something which would not be allowed under today’s regime! A ‘phone call  “could I pop down to the office – it’s about your motorbike”. My immediate thought was that someone had parked a lorry on it, or at least knocked it over. But no – there was a problem that a lot of the BBC dispatch riders were off sick, and there were a number of packages requiring urgent delivery. “Would I mind being a dispatch rider for an afternoon?” Armed with an A-Z map, off I went! That was fun. Life at Western House was fun!

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