Memories of the BBC Research Department 2

Now where did I get to?  Ah, yes, I had just become a fully fledged Research Engineer in Special Projects section under Stan Edwardson.  I found this video of Stan, strange how now he looks so young yet then he seemed relatively ancient.

If Stan ever reads this I trust he will forgive me, but we used to joke endlessly about about his vetting of our Tech Memo's and Reports. As section head he had, of course, to vet everything that left the section, and after a vetting session one's style and sometimes one's content was hardly recognisable so the game used to be, how little could one get away with writing seeing as Stan would re-write it all anyway?

Here I designed a prototype receiver for the CARFAX radio traffic warning system which Stan so loved to demonstrate, see R&D Report 1979-10.  The photo in my previous blog shows one of the RF transistors used in this "straight" or TRF design. The CARFAX system was cellular in operation - a bit like today's cell-phones only medium wave, so susceptibility to interference from adjacent cells was an important consideration. Some rather tedious work followed R&D Report 1982-05.  Sadly the system was never adopted. The original Carfax is, of course, the cross-roads at the centre of Oxford.

In a later project the CARFAX receiver was integrated into a "car radio" design intended to demonstrate some digital techniques like PLL tuning, a digital bar-graph tuning indicator, a hand-made angle encoder for volume control and so forth.  Nowadays all that is standard fare but back then... The whole thing was shoehorned into standard car radio width and height, but it was two or three times as deep as a normal car radio. So Stan referred to it as the "long bonnet (or hood) car radio".

I shared an office with Andrew Lyner whose humour and no-frills view of life I greatly appreciated.

Another engineer, Dr Susans or Susie to us, was somewhat longer in the tooth than Andrew or I, indeed he was almost part of the Special Projects section furniture. His office seemed to be the height of disorder and yet he could find a relevant document within seconds if you asked him a technical question.  He had a voice a bit like a rasp and, for a hobby, made lace bobbins from exotic timbers.

The other main work of the section at this time was on radio data on VHF f.m. (now known as RDS) and on a.m. I was particularly involved in the latter which ended up being applied to Radio 4 long wave (then 200kHz, now 198kHz) for teleswitching electricity meters. The system involved phase modulating the carrier at subliminal frequencies, whilst not interfering with the long term frequency precision as this transmission is used as a frequency standard. This system was awarded the Queen's Award for Innovation in 1987 and I was kindly invited back for the ceremony as I had been part of the team which invented it.

We carried out compatibility trials which meant designing special test gear and a fun trip to Scotland driving around in a van operating it. Our work in Research Department often involved adding more features without affecting existing viewers / listeners, hence stereo had to be compatible with mono, colour TV with monochrome, and now radio data with radio.  Phase modulation is orthoganal to a.m. (amplitude modulation) so will not interfere with it in an ideal world. But the world is not ideal, especially in this "mush area" inbetween co-channel transmitters in Scotland as explained in R&D Report 1982-22.

And then I handed my notice in...