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Oral-History:Viggo Kjaer

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About Viggo Kjaer

Viggo Kjaer
Viggo Kjaer

Viggo Kjær studied electronics under Peder O. Pedersen and Jens Nielsen at the Technical University in Copenhagen.  After completing his degree in 1939, Kjær designed receivers for companies manufacturing radios. In 1942 Kjær formed the Brüel & Kjær instrumentation company with his University colleague Per Brüel. Beginning in 1944, Kjær focused on this company full time, taking on management and design roles.

In this interview, Kjær describes emphasis on Danish components in early 1940s radio manufacturing. He assesses the influence of World War II on components availability. Kjær describes the decision to form Brüel & Kjær; P. O. Pedersen's advice against forming an instrumentation company; product markets; the company's work as a subcontractor for Philips; and Brüel & Kjær instruments including the RC analyzer, acoustic instruments, and the Geiger counter. He describes the company's growth, production increases, and design shifts in the 1950s and 1960s.

For further information see Per Brüel Oral History.

About the Interview

VIGGO KJAER: An Interview Conducted by Frederik Nebeker, Center for the History of Electrical Engineering, 18 July 1996

Interview #305 for the Center for the History of Electrical Engineering, The Institute of Electrical and Electronics Engineers, Inc.

[Note: The interviewee's surname, 'Kjær' is usually written in English 'Kjaer'.]

Copyright Statement

This manuscript is being made available for research purposes only. All literary rights in the manuscript, including the right to publish, are reserved to the IEEE History Center. No part of the manuscript may be quoted for publication without the written permission of the Director of IEEE History Center.

Request for permission to quote for publication should be addressed to the IEEE History Center Oral History Program, IEEE History Center at Stevens Institute of Technology, Castle Point on Hudson, Hoboken, NJ 07030 USA or ieee-history@ieee.org. It should include identification of the specific passages to be quoted, anticipated use of the passages, and identification of the user.

It is recommended that this oral history be cited as follows:

VIGGO KJAER, an oral history conducted in 1996 by Frederik Nebeker, IEEE History Center, Hoboken, NJ, USA.

Interview

INTERVIEW: Viggo Kjær

INTERVIEWER: Frederik Nebeker

PLACE: Vedbæk, Denmark

DATE: 18 July, 1996

Family and education

Nebeker:

I’d like to start by asking you where and when you were born.

Kjær:

Yes. I was born in Ulev near the Jelling Stone.

Nebeker:

The famous Jelling Stone?

Kjær:

Yes. My family and father were farmers for generations back.

Nebeker:

Was it, how did you come to get a technical education?

Kjær:

After college, I studied over in Copenhagen at the Technical University.

Nebeker:

Was that, wasn’t that difficult to do for a farmer’s son?

Kjær:

No, not particularly. But I had to move off from home and go to live in Copenhagen.

Nebeker:

Were you always interested in technical things?

Kjær:

Yes.

Nebeker:

Did you have a crystal radio when you were young?

Kjær:

Yes. And also a tube radio and-

Nebeker:

That you built yourself?

Kjær:

Yes. A gramophone, and even a small transmitter.

Nebeker:

I see.

Kjær:

I called the neighbors.

Nebeker:

So you decided at an early age that you wanted to go into electronics?

Kjær:

Yes.

Technnical University studies

Nebeker:

So when you went to the Technical University you took the weak currents, or communications, line?

Kjær:

Yes.

Nebeker:

Who were your principal teachers?

Kjær:

It was P. O. Pedersen, and his assistant professor.

Nebeker:

Who was that?

Kjær:

Jens Nielsen. But by that time we had an all around electric education. We also learned something about-

Nebeker:

Power engineering.

Kjær:

Power engineering, yes, and machine design, and other things.

Nebeker:

I know that the Technical University here was one of the very first to offer this weak current engineering.

Kjær:

Yes. I think that came out from P. O. Pedersen’s cooperation with Valdemar Poulsen.

Nebeker:

And I know a lot of engineers who were trained there then went other places and did very important work. Did you feel you got a very good education?

Kjær:

Yes, I think not very much about weak current but -

Nebeker:

Is that right? It was more of regular power engineering?

Kjær:

Yes, I picked up the basic science.

Nebeker:

You also had mathematics and physics?

Kjær:

Yes, lot of it.

Nebeker:

What did you do when you completed your engineering degree?

Industrial employment in radio

Kjær:

Then I came to a manufacturing company who made radios.

Nebeker:

What was that company?

Kjær:

Company was Tobias [Jensen and another company, 2R, and then] the Danish department of Philips.

Nebeker:

I see, so, as soon as you completed your degree, or maybe, did you start any work before you completed your degree?

Kjær:

No.

Nebeker:

So when you completed your degree you looked for jobs in the radio field?

Kjær:

Yes, yes.

Nebeker:

And what were you doing with those companies?

Kjær:

I was designing radio sets.

Nebeker:

Designing receivers?

Kjær:

Yes.

Nebeker:

What years, what year was that, that you finished?

Kjær:

That was ‘39.

Nebeker:

What was happening with radio design at that point? Was there anything particularly new?

Kjær:

It was of course in the tube age and the tubes were developed a few years before the [unintelligible] were put in them, and it was a slowly developing field.

Nebeker:

I remember one thing that was very much emphasized in the United States in the 1930s was reducing the cost of radios, so the engineers were trying very hard to use fewer tubes, or you know, to do things in a less expensive way.

Kjær:

Yes, it was the same over here. We had in Denmark a very developed component industry so we could make Danish radios built from Danish components.

Nebeker:

Is that right?

Kjær:

We did, except for the tubes which came from Holland.

Nebeker:

I see. Were these Danish radios sold outside of Denmark?

Kjær:

Not very much. And we had about ten or twelve manufacturers for this country.

Nebeker:

Was that right?

Kjær:

They all died afterwards.

Nebeker:

So you worked for three different radio companies?

Kjær:

Yes.

Nebeker:

How long for each of them? Do you recall?

Kjær:

I stopped in ‘44, five years in all.

Nebeker:

I see. The Philips, that was a Philips branch in Denmark that you worked for?

Kjær:

Yes.

Nebeker:

Did they manufacture radios here?

Kjær:

Yes.

Nebeker:

I see.

Kjær:

And they also manufactured radios during the war.

Influence of WWII on industrial design

Nebeker:

How did the war affect your work or your daily life?

Kjær:

In the work I think the main thing was that when we should make a design we had to first, the thing to do was, go into the stock room and see what is there, for components and so on. Then we made a design on that.

Nebeker:

I know, Gunnar Pedersen told me in what short supply transmitting tubes were during the war because they had been imported. So that’s interesting.

Kjær:

Yes.

Nebeker:

So you had to make designs on the basis of available components?

Kjær:

Yes. For instance, if you’d make a thing with three tubes, it would be three tubes, might be from three various series, one six volt, one twelve volt, and so on.

Nebeker:

So tube manufacturing continued during the war? I mean, radio manufacturing continued during the war?

Kjær:

Yes, there was. We were short of tubes, because, and especially when the Germans took over the tube factories in Holland. And then a couple of Danish manufacturers started up a small tube plant in Denmark, with very little success.

Nebeker:

Oh. Did they actually produce some tubes that were used in -?

Kjær:

Yes.

Nebeker:

But of course it was inferior.

Did you know of the Danish engineer Arne Schleimann-Jensen who went to Sweden and set up a tube manufacturing company there, that started in something like 1939. Was there, could you import tubes from Sweden in those years?

Kjær:

No, not to my knowledge. Of course the Germans had tubes. Especially because when the Germans came here they went to the various major manufacturers of radio and tried to make them produce some of their military stuff.

Nebeker:

Oh?

Kjær:

But they didn’t like that of course, and one or two of them instead went to German receiver manufacturers and made contracts with them to make their receivers, ordinary home receivers. And when then the Germans came in and asked them to make military stuff they said, “No, we can’t, we always already work for this or that company.”

Nebeker:

And they did that just for that reason, to be able to say to the Germans that they were under contract.

Kjær:

Yes. So some tubes came in to Denmark.

Nebeker:

Was it frustrating to be a radio engineer under those conditions?

Kjær:

No, the tasks were somewhat difficult.

Nebeker:

Did you enjoy the work you were doing?

Kjær:

Yes. I did.

Nebeker:

What about personal life, were there hardships here?

Kjær:

Not compared to what there were in Holland and other places.

Kjær:

There were shortage of a lot of things of course, but not of food because we always produce a lot of food in this country.

Brüel & Kjær instrumentation company

Nebeker:

So you continued to work for these radio manufacturers until ‘44 you said?

Kjær:

Yes.

Nebeker:

What happened then?

Kjær:

Then we started, in ‘42 we had started our own company, and, as a part time job. ‘44, it became for me a full time job.

Nebeker:

I see.

Kjær:

At the same time, Per Brüel, he went to Sweden and lived there for some years.

Nebeker:

Okay, and this was, the first products, well, it says here that there was laboratory apparatus, and then....

Kjær:

Yes. I think that’s a picture of the very first, first instrument..

Nebeker:

I see. In English would you call this an RC analyzer?

Kjær:

Yes. It was based on an article which we read in the IEEE Proceedings. This amplifier is tunable by means of a parallel [unintelligible] network.

Nebeker:

Yes, Mr. Brüel told me something about that. So this was the first product you produced in large numbers?

Kjær:

Yes. It was really produced well, when Per Brüel was in military service, in a workshop of the Danish army.

Nebeker:

And there were people interested in buying such a device?

Kjær:

Yes, a few were interested.

Nebeker:

So was this what made you decide to set up the company? This product?

Kjær:

No, not especially this product. This decision was made when we studied together at the university.

Nebeker:

So you decided that you would work together to produce instruments, was that the original idea?

Kjær:

Yes, yes, I think so.

Nebeker:

That’s a little bit surprising. One wouldn’t imagine there’s a large, a huge market for instruments.

Kjær:

No, no in fact, P.O. Pedersen said to us, “Don’t do it. One of you might be able to have make his living by that but not two.” [laughter]

Nebeker:

What made you interested in instruments? Maybe there’s no answer to that, but....

Kjær:

No. It was challenging.

Nebeker:

So did, did increasing orders suggest to you that you were really going to make enough money at this and then you quit your job, is that how it happened?

Kjær:

Yes.

Nebeker:

Where did these orders come from? Were they within Denmark?

Kjær:

In Denmark, yes. And Norway and Sweden. I think the largest order we got came from Philips. Because Philips was by that time also selling measuring instruments but the manufacturer of this in Holland was blocked. So they had nothing to sell. Then they came to us and asked us to, and in return they would supply components to us.

Nebeker:

Oh, would they be sold as Philips instruments?

Kjær:

Yes.

Nebeker:

I see so you’re producing as sort of a subcontractor or a supplier for Philips?

Kjær:

Yes, they bought our design as it was and put the name of Philips on it.

Nebeker:

I see. Did that bother you?

Kjær:

No, no, we took any order we could get. [laughter]

Architectural and acoustic instruments

Kjaer:

And other orders came from the architectural or acoustic branches: people who made concert halls and movie theaters, and also for schools.

Nebeker:

I see. So from the beginning you were producing acoustic devices, for acoustic measurement?

Kjær:

Yes, that was one thing at least, but also any other thing we could make.

Nebeker:

So there was no decision that you should focus on acoustic instruments?

Kjær:

Somewhat, but not as the only thing we make. The acoustics came in when Per Brüel, he worked on his doctor’s degree....

Nebeker:

I see, so you tried different areas of instrumentation?

Kjær:

Yes, we did. We made two valve meters, and comparison bridges for components, and make tuning equipment for the receiver factories, and cabling so they could test the receivers. Then there were the acoustic instruments; oscillators.

Nebeker:

How did product development work in these years? Was it typically one of you who had the idea for a new instrument and you’d both work on it or did you each work on your own instruments?

Kjær:

In the first time we worked on one instrument, all of us. We were three by this time, Per Brüel, he was the person who was doing the selling. He came and....

[unintelligible passage]

[Tape one, side two].

Nebeker:

So, you were telling me some of the different acoustic instruments.

Kjær:

In ‘47 I think, there was an international congress of acoustics in Poland. Per Brüel went there and he came back with a lot of ideas of things we could make for the acoustics. And we started up with it. Then more or less, the other product lines, they faded out.

Nebeker:

I see.

Geiger counters

Kjær:

With the exception of Geiger counters, which we had a program on for a few years. It was really, I think, modern in all countries, areas, every country should make their own radioactivity stations.

Nebeker:

Was that an important product for you?

Kjær:

Indeed, yes it was.

Nebeker:

That’s something you designed, the Geiger counter?

Kjær:

No, it was designed by our first employed engineer.

Brüel & Kjær structure; corporate growth

Nebeker:

So the company was gradually growing, I can see here by the late forties, that you were getting up to thirty employees or so.

Kjær:

Yes.

Nebeker:

Then, by the end of the fifties, you were at 350 or so employees.

Kjær:

Yes.

Nebeker:

So you got other engineers to work on design as well?

Kjær:

Per Brüel was traveling all the time, and couldn’t participate in design. And Ulgar Nelson was busy with manufacturing, producing these instruments.

Nebeker:

Did he take charge of the production side?

Kjær:

Yes.

Nebeker:

So was it a very clear division of labor with the design group, and the production group, and the sales side?

Kjær:

Yes.

Nebeker:

How did the growth of that design group go? Initially, it’s you and Mr. Brüel, and then you said you got, at the time of this Geiger counter, what is that, ‘49, another engineer?

Kjær:

Yes. The first engineer was hired about that time, and then we had three design engineers, as I remember, and then when he came here for the end of '60s we had perhaps twenty-five or so.

Nebeker:

By the end of the fifties, by 1960 you had twenty-five design engineers?

Kjær:

Yes, I think so.

Management and design roles

Nebeker:

So by this time you were more a manager than a designer, is that right?

Kjær:

Yes, that’s right.

Nebeker:

Did you, did you keep your hand in the design itself?

Kjær:

Not very much after 1960. In ‘59 we designed the recorder here, that was my last major design job.

Nebeker:

I see. Did it bother you to become more of a manager and less of a designer?

Kjær:

Yes, really it did, but it was necessary.

Nebeker:

Yes. Was that a difficult job, to try to get the design work done for a growing company?

Kjær:

No, no, we didn’t have any strong organization, we had small groups who made their own designs, instruments. At most we tried to hire the best engineer we could get, and then we made up an organization which [unintelligible] about him.

Nebeker:

Was this the graduates of the Technical University that you hired?

Kjær:

Well, not many perhaps, but many of them, the others came from the other technical high schools, for instance, Arhus. Because over there, when you wanted to start, you had to be an apprentice at first, and finish your education there, and then you came in and got all the theory once you had the practical. So they were very good at designing things which would be introduced.

Nebeker:

Is that different from what happened in Copenhagen?

Kjær:

Yes. In Copenhagen they learned the theory and, in my time, we had one year of practical work. I think in the middle of the '50s it was pushed out and they had nothing.

Nebeker:

Is that right? Did you, in general did you prefer graduates of the Arhus school?

Kjær:

Yes, that was our main source of suppliers.

Nebeker:

I see, so that’s very interesting. So you think that they got a better education because they did practical work before they got the theory?

Kjær:

For our use at least. But later this changed, when we came to the digital designs, then we had more of the Copenhagen people.

Nebeker:

Oh. And is it the case that with digital electronics, the practical experience is less important?

Kjær:

It’s less important I think.

Sales, markets, and products, 1950s

Nebeker:

So through the fifties you had very rapid growth?

Kjær:

Yes.

Nebeker:

Something like ten times as large at the end of the '50s as at the start of the '50s.

Kjær:

Yes, we had twelve years there where the number of employees was fifty percent up every other year.

Nebeker:

My goodness. Which must mean that sales were going well?

Kjær:

Yes.

Nebeker:

Were you, were you able to meet customer demand?

Kjær:

Yes.

Nebeker:

So you were able to grow fast enough to do that?

Kjær:

Yes. Per Brüel, he traveled a lot over the month, and we had a small market everywhere.

Nebeker:

Did you take part yourself in marketing or finding customers?

Kjær:

No.

Nebeker:

Yes.

Kjær:

We had a very sharp division of work.

Nebeker:

And that suited you?

Kjær:

Yes, it suited both of us.

Nebeker:

Yes.

Kjær:

Because we were around different people at various times. There were with us, division of working field, it went on very well.

Nebeker:

So let’s see, you’ve got a lot of products coming out in-

Kjær:

Far too many.

Nebeker:

In 1958 alone there seem to be six or eight products in the acoustic area.

Kjær:

Yes, because Per Brüel had the idea that we should make everything which an acoustical engineer could use. So he shouldn’t need to go anywhere else to buy something.

Nebeker:

Were there practical arguments for that? I mean, were there compatibility problems if an engineer tried to use instruments from different.

Kjær:

We tried to make it that way. [unintelligible] you should fit in into something or the recorder.

Nebeker:

Yet you still have some other products, or products in other areas.

Kjær:

These are our compression bridge for components, that was in our field.

Nebeker:

What are these?

Kjær:

This means what new technologies we used.

Nebeker:

I see, I see, okay.

Kjær:

And besides acoustics we had something for the vibration machines.

Nebeker:

I see, okay, for non-acoustic vibration measurements.

Kjær:

Yes.

Nebeker:

I see. Where were those used, those accelerometers?

Kjær:

They were used in machine design for instance, to measure the vibrations in machines.

Nebeker:

I see.

Kjær:

And for measuring the [unintelligible] of the machine, when it was worn down, the vibrations [unintelligible]

Nebeker:

I see. Was that something that would just be attached to the machine to measure its vibration level, or is that something that’s just built into the machine to, monitoring it?

Kjær:

In these years I think it was an instrument, like a sound level meter, we had a vibration level meter.

Nebeker:

I see. I see you’re starting to use germanium diodes in the mid-50s.

Kjær:

Yes. After I think here, we still used those tubes.

Influence of transistors and printed circuits, 1960s

Kjær:

But then transistors came into the market in-

Nebeker:

In the early sixties?

Kjær:

Yes. And as soon as they could do the job just as well as the two others, then we changed the design.

Nebeker:

And why would one choose a transistor if they did the job equally well?

Kjær:

Well, a lot of our instruments were, should be used in the field, and be portable. And then it was very convenient.

Nebeker:

Did the availability of transistors change circuit design very much?

Kjær:

Yes, very much. At the same time the printed circuit technique came out, and we used it.

Nebeker:

How is it that? So the transistors that were available were not simply counterparts to existing tubes?

Kjær:

No.

Nebeker:

So you had to redesign an instrument to use them?

Kjær:

Yes. A few instruments were transistorized in the same design. For instance this one, this came out in a transistor version. But most of them were designed from the bottom in terms of transistors circuits.

Nebeker:

Was that something that, was that difficult to translate, was that a difficult transition for someone who had been trained as a tube person?

Kjær:

Yes, and they had to educate themselves to work with transistors. We arranged courses in the company for-

Nebeker:

Within the company?

Kjær:

Yes.

Nebeker:

What was made possible by the transistor in the types of instruments you were making that wasn’t possible with tubes? Certainly the portability, and the, how rugged an instrument was, is one thing.

Kjær:

Yes. Nothing, I think [?].

Nebeker:

Was it maybe lower power requirements with transistors in some cases?

Kjær:

His first instrument here, half the box here were batteries.

Nebeker:

Yes. What about the printed circuits, was that something difficult for a manufacturer to move to?

Kjær:

No. It wasn’t. We had a technique in the house for making these designs.

Nebeker:

By the designs-

Kjær:

Silk-screening, and so we could just use that for making the circuits. So it wasn’t really difficult to do that.

Nebeker:

Obviously that changes layout, but did that change design at all?

Kjær:

Yes, then the design should be more complete on the drawing board, before going out in models. You couldn’t just add a cord or put a component in and so....

Nebeker:

I see. And did that reduce production costs significantly?

Kjær:

Yes.

Nebeker:

Let’s see, we have some measures here of number of instruments sold, in, say by 1950 the company had sold 2000 instruments, roughly. By 1960, 40,000 instruments, roughly. So in the ‘50s, you’re turning out instruments in large numbers, and you had gone, I assume, to some kind of assembly line production?

Kjær:

Yes.

Nebeker:

Were there real difficulties do you remember in this increase of production from dozens to thousands of instruments a week?

Kjær:

No, I don’t remember any particular difficulties with....We had to convince perhaps some people in production that it wasn’t necessary that they personally made all the instruments.

Microphones

Nebeker:

Yes. Okay, so I’d say just looking at this on the largest scale, the ‘50s were a period of very rapid growth for the company. In the ‘60s, going from something like 500 employees, to, well, 1300 or so, so that’s also very significant, two and a half times at least growth in the ‘60s. As you look over these products, what were the ones that were most important for you?

Kjær:

I think about here. Microphones came out, and sound-level meters. And that were things that could be sold in large numbers.

Nebeker:

I see. What were these microphones used for?

Kjær:

For measurement.

Nebeker:

So they just had to be very sensitive and accurate.

Kjær:

Yes, sensitive and very stable. And a broad frequency range.

Nebeker:

Were they exclusively for instruments?

Kjær:

Yes.