Hodgkin and Barcham continued with the installation and development and improvement of the 10 cm air interception equipment in Blenheims and in the Beaufighters, and I was given another job and that was to make an advanced air interception system in which the paraboloid scanner would lock onto this target and enemy and it could be done by blind firing. Well, I worked on that and with... and I had the great help of FC Williams who was another electronics expert, who had wide ranging applications in TRE, as we were then called TRE, the Telecommunications Research Establishment, and FC Williams was particularly good on this.

We devised... I think I originally had a system from Metropolitan-Vickers in which I could lock the echo so that the scanner... I could use the echo so the scanner would lock itself on, onto the echo. And I had this system going. I did many, many flights from the bumpy airfield at Christchurch with FC Williams and another colleague, called Ritson, and we had a good system working quite reasonably well by the end of 1941, and the only one interesting problem. That is the fading, the high speed fading of the echo from a target aircraft, and you see we were using pulses, very loud pulses of 1,000 a second or thereabouts and the high-speed fading, we had somehow to cope with this, because it was disturbing a long follow, and I began to build a high-speed camera, so that we could analyse the... what was happening with this high speed fading.

Blackett then frequently came to see how we were getting on. He had then been... I think he was first of all a scientific advisor general pike of AA command and then Coastal Command, and later on the Director of Naval Operational Research in the Admiralty, but he frequently came to see how we were getting on and one day he said, 'What are you doing?' And I said, 'I'm making a high-speed camera to study the fading of the pulses from the target aircraft', and he said, 'Oh'. He said, 'Well, I think I've got a young man who... who might be able to help you'. This is a remarkable story.

A few days later, Andrew Huxley arrived. Now, Andrew Huxley was another of these brilliant young Cambridge people, a physiologist. And Andrew Huxley said he'd come to help and I said, 'Oh, where's your equipment?' He said, 'Oh'. He pulled a Leica camera out of his pocket, and I said, 'What are you going to do?' He said, 'It's easy'. He said, 'I've taken away the lens and I'm going to put this in front of the cathode tube and I'm going to do that for the film, and so that happened'. Now, those original records are now with my own... many of my own papers and records in the archives in the Imperial War Museum and you can see it just worked. He did this and that... from that we were able to analyse. The pulses were separated, of course, one by one by one, no problem in analysing the type of fluctuations which were occurring. That's an interesting sideline. Huxley again, this brilliant scientist. Master of Trinity, Nobel Prize winner, President of the Royal Society and he is still a friend. I still see him occasionally in London, but I'm sure he's forgotten that episode. Anyhow, I was about to... I had arranged to get a Beaufighter and to make arrangements to have this lot follow blind firing equipment manufactured properly and installed in a squadron of Beaufighters.