I took on my first employees in 1979 because I had to get the products working. The company's operations were purely in electronic warfare until 1989, when I went into a joint venture with a US corporation. That released some engineering capability, and that's when we looked at the base station and mobile telephone business.
As the company grew, I employed a lot of my ex-students, including 15 of my PhD graduates. They came because I offered them the opportunity to do what they really wanted - research and development. Other companies don't offer the same opportunities, and you don't get R&D in universities.
Chris wasn't my student, but he did his PhD in a related area. I had a reputation for being creative and I did win many awards, so from a technical viewpoint I think Chris respected the work I did. We didn't work together until five years ago; we struggled to get him made head of the Leeds department of electronics. Technically, he was extremely capable, but unusually, he was competent at managing people and getting things done. The two don't normally go hand in hand.
I promised the Leeds vice- president, Professor Alan Wilson, that I wouldn't poach Chris for Filtronic. But last August, completely out of the blue, I was in the department early one morning and saw an e-mail notice that Chris had resigned and was joining a large American corporation as director of technology. I tracked him down and got him to come out to lunch. I worked on him for the next 24 hours and won him over. I said we would give him the opportunity to do more than just technical things.
Chris has taken a lot of weight off my shoulders. He's similar to me, rather than just complementing me. He's taken on the organisation of technical co-ordination worldwide, but he's also on other functions, such as relationships with the major shareholders in the City.
We both have the ability to lecture, to stand up without notes and convey a lecture with interest. Chris is creative in a slightly different way - more thorough and organised. My strengths are that I have always been creative in research and I can motivate other people.
We both believe if somebody is wrong, you persuade them by argument. I help people rather than chastise them. I don't believe in revenge: you help whoever it is to succeed in what they are trying to do.
I haven't been able to be involved in the technical side so much lately, but I have had to be creative in other aspects of the business, the strategy and the structures. The challenge is always to get good people, and we've been successful at that, although not as successful in America.
The satisfaction is in growth. We aim to be one of the biggest electronics companies in the UK. We have always had engineering excellence, but that's complemented with other things such as quality and performance in delivery.
Chris does a tremendous amount of travelling but, when we're in the office together, we communicate a lot. When he's away, mobiles are our main method of communication. Most of my thinking time is related to either the company, my family or Bradford City Football Club, where I'm deputy chairman. I don't watch football with Chris; it's a completely different group of people. I have needed not to mix the technical and business world with my personal life.
CHRISTOPHER SNOWDEN: I've known David since I was an undergraduate and he was a young lecturer. He's always been very dynamic; even the students realised he was a very bright guy, partly because he's enthusiastic for his subject and that oozes into his lectures. It was evident his interests lay in the purity of his subject and research, perhaps more than in teaching it. But he'd convey his enthusiasm.
I graduated in electronic and electrical engineering and went to work for Philips, then went back to Leeds to do a PhD: I wanted to study microwave engineering and the subject area drew me there. Having come from industry, I was highly motivated, so it took me less than three years. I was going to go back into industry but I was offered a lectureship in York.
I've always loved teaching but, like David, my first love is research, the sense of discovery, taking an idea and applying it so you can do something better than has been done before.
In 1989 I went to America to work for the corporation M/A-COM as senior staff scientist in their R&D centre. I wanted to learn about corporate structures, how technical and managerial issues were dealt with. I did several due diligence exercises for acquisitions and helped to develop relationships with large companies. I also played a central role in developing semiconductor technology plans as well as new transistor designs. David tried to recruit me on numerous occasions when he was developing products for the military.
Historically, the military has always been the most demanding in terms of technical performance, and the sheer challenge of trying to meet that specification was something other companies couldn't or wouldn't do. It's difficult as a new entry to the market, but he had a unique product - suspended substrate stripline microwave filters.
I've always been ambitious and I wanted to develop something with growth potential. David's work was strongly filter-based and at the time my expertise didn't represent his major product areas. A man has to carve his own niche, and I didn't see how I could utilise my special skills. In late 1991 I came back to the UK to assess where I was going, and a year later I was given a personal university chair at Leeds, based on research performance.
Four years later, I was elected head of department. We split the department into three sectors: electronic and electrical engineering, and two research institutes. I wanted the department to achieve international excellence and worked with the staff to refocus themselves. It was a controversial thing to do, but people have to recognise the world is changing. I ran the department as a business and David would have done the same.
Hewlett-Packard endorsed a chair at Leeds, and in 1997 I went to the States to approach the corporation AMP to do the same and establish an alliance. They offered me the vice-presidency of their R&D department and I was very flattered, but I had an obligation to the people at Leeds.
I tried to get hold of David to talk about it, but he was on holiday. I wrote to all the staff explaining what I was going to do, at which point David came bounding in and said: "Is it too late to talk about an alternative career?" He outlined his vision: he was about to complete an acquisition that was 100 per cent in my area, and I could see it had the potential to grow. The synergy was there now. I decided I would join him.
I didn't know until later about his agreement with the vice-chancellor; it impressed me that David had felt that way, and honoured it. He is a very private person: I can remember going out for a drink in the pub with him in 1975, but by 1978 he wasn't doing that any more. It was the right thing to do. If you don't hedge your private life, you find it disappears into the work. I've tended to separate the two as well. David had an inspiring and human touch to management. He cares about the people in his company, and that's a positive quality.
I didn't appreciate the extent of his compassion and interest in people's welfare until I joined his company. I've known a lot of chief executives and he's the only one I've met of that calibre.