Memories of the BBC Research Department

Thomas Alcock's Kingswood Warren 1837

The Research Department at Kingswood Warren 1980

Until 2010 the BBC Research Department was located in Kingswood Warren in Surrey. After graduating from Oxford in 1974 I was employed here and became a Research Engineer before leaving in April 1981. The reasons for leaving are another story.

There were four of us in the intake that year. We rented the upstairs of a rather dilapidated property 20A Thicket Road whose main claim to fame was that one evening, whilst we are all minding our own business, there was a large crash and, upon investigating, we found that the bathroom ceiling had collapsed. I would have been more interesting hard one of us been taking a bath at the time. The house was demolished some while after we moved on. It was that sort of house. But the purpose of this blog is not to honour 20A but to recall my time at Kingswood Warren.

Rear of 20A Thicket Road, Sutton, Surrey

The department was divided into groups, and the groups into sections. Each section dealt with a particular area of research and would employ a section head, about 6 engineers and about 3 technicians. Graduates rotated through various sections spending several months under a mentor in each before becoming qualified. And so it was that I started life in Baseband Section under John Chambers. I could not have had a better mentor. He led me by small degrees into a very ambitious project: to start with I was to design a "gearbox". He explained that digital TV, then in its infancy, might sample at 2fSC, 3fSC or 4fSC, where fSC was the colour subcarrier frequency for PAL. The gearbox was to take any one of these as its input, and output  fSC. In those days such things were done with discrete TTL logic chips like 7400. To satisfy timing requirements I was obliged to use some 74S chips. The Texas TTL data book was my bedtime reading.

This done, John gently moved me into the rest of the project and when that was done I found I had designed and built an entirely digital PAL colour bar generator comprising several cards jammed full of TTL chips all hand wired (i.e. peices of insulated wire soldered to connect between the pins of the DIL TTL packages). The less technical of my reader may be getting lost so here is a helpful picture.

These components are all from my own collection, kept safely, for memories sake, through many decades of house and country moves. The first two predate my BBC days so must have come from my childhood. From left to right we have:
  • OC71  a small signal germanium transistor made by Mullard
  • OC81  a higher power version of same (200mA maximum)
  • BF195 a high frequency (200MHz) transistor I used in the CARFAX receiver q.v.
  • ASY24 another germanium transistor
  • LM310 an analog integrated circuit - a voltage follower
  • A real live BBC Research Department issue 2% tolerance 330K resistor
  • BC109 a very popular audio transistor at that time - this time silicon
  • 74LS163 similar to the sort of TTL logic chip used in the colour bar generator

Today a colour bar generator might be one small part of the capabilities of a single silicon chip. And PAL is almost legend.  Back then the Research Department had built a digital frame store - it could store a whole TV frame (25 of these per second), an essential ingredient to being able to convert between different TV standards such as American NTSC and English PAL. This frame store occupied a 19" wide rack of equipment some 5 feet high and consumed vast amounts of power at 5V. Today a single chip can store many frames and cosume a few milliamps.  Such is progress.

"Home office" was the practice of making one's own electronics projects during lunch time or after hours. This was encouraged, indeed until shortly before I joined, the BBC actually provided component parts free of charge - but this was stopped after it was found that certain individuals were making a business of it. During working hours it made no economic sense to re-use resistors and other small parts from discarded circuits, so they went in the bin. During lunch time it made very good economic sense to retrieve those parts out of the bin. The 330K resistor in the picture is one such. I have long had a love affair with colour coded resistors - a 5% 56K resistor is particularly beautiful (green, blue, orange, gold) and its existence could be responsible for my choice of career.  Really.

From Baseband... well I regret I cannot be sure of the section names, but here are some of the projects I worked on, some of which spawned Research Department Reports.

Digital tape recording was in its infancy, and the goal was to maximise the number of bits per inch. So I did some research into codebook modulation (as opposed to delay modulation, bi-phase) see R&D Report 1977-33 : New block-codes for digital tape recording.  Despite all this hard work, hard disks today (which are effectively tape recorders) still use the simpler bi-phase or delay modulation.

Each engineer had an office, and each laboratory was presided over by a technician, but graduates had no place to rest their head, so in this instance I occupied a corner in Eric Grantham's laboratory. Eric lived a strange and lonely existence by himself in a mobile home but when at work would sing all sorts of silly songs for example this very apt instruction to would be engineers:

Mend it, mend it, do not bend it,
 Do not bend this wireless set...

to the tune of Beethoven's Ode de Joy.  He wasn't a bad sort - and, I think, was the only person from work who attended our wedding - here he is, sneaking into one of our official album photographs: he's the one holding the camera behind the happy couple.  Sadly I have no other photographs of people from BBC days.

Talking of technicians... one was either born to be a technician or an engineer and never the twain could meet. Engineers had to be graduates, usually of a high class. Technicians might I suppose be City and Guilds. The difference between an engineer and a technician was apty summed up by "a technician washes his hands before going to the loo, an engineer washed his hands afterwards". The technician's job was to oversee the laboratory and do assembly work or testing under the direction of the engineers, and many were happy in this role. Some, however, aspired to doing the work of an engineer and frankly some were as good as the engineers. But it could not happen. The BBC was too staid. We had a rigid caste system. Another example of this was that section heads and above could not eat with the rest of us - they ate in what we called the "golden trough". Talking of the staff canteen, I have to say that all BBC food I have tasted has been above average, and in those days it was also usefully subsidised. A bowl of BBC fruit crumble and custard, or a BBC cheese scone, cost very little and could keep one fuelled for many an hour.  Occasionally I would shell out and treat myself to cheese omelette and chips.

In the audio section (in those days they actually designed studio speakers) I designed and made a digital reverberation meter. It used a novel method by Dr Susans q.v. for obtaining the logarithm to base two.

In the radio frequency section I designed and built a digital correlation meter to analyse the outputs of two radio receivers for testing diversity reception. This thing was effectively a computer, but made out of discrete TTL chips. It had an arithmetic control unit and a primitive instruction set for summing the various ingredints required for correlation (sum of X, X squared, Y, Y squared and XY), but used the inners of a calculator for doing the more complicated (but slower) calculations at the end (divisions and square root) to display the correlation coefficient.

Housed at Kingswood Warren but arguable not a part of the Research Department was the spectrum planning section whose job it was to figure out what transmitter frequencies and powers could be used and where. It used to be said that their motto was "if a job is worth doing it is only just worth doing". Such was the discrimination between them and the rest of us.

And then I became a fully fledged Research Engineer - but this blog has already exceeded the length normally accepted by civilised bloggers so I will break for another time...

1 comment: