Oral-History:Johan Schleimann-Jensen

About Johan Schleimann-Jensen

Johan Schleimann-Jensen was born in Denmark in 1906. He was educated at the Polytechnic Lienstadt and worked as an independent inventor from 1925 to 1935. His was awarded his first patent in 1926 and received two patents for advances in radio tube design in 1935. An attempt to finance his own tube factory led him first to Sweden and then to America in 1936, where he worked for Sylvania until 1939. He returned to Sweden to start a tube factory for Ericsson in 1939 and continued in that factory until 1948, becoming managing director in 1945. From 1949 to 1959 he headed his own small research lab with a focus on tubes for military applications. In 1959 he went back to work for Sylvania at Mountain View, CA, and remained there until 1964. He then worked on surge arrestors for Svensk Electronar. After retirement in 1974 he continued to consult for Erickson on surge arrestors. His sons Arne and Johan started up their own company in 1983 to develop arrestors for Ericsson. Schleimann-Jensen suffered a series of strokes beginning in 1984 and died in 1991.

The interview consists of two parts. The first part is a discussion with Johan Schleimann-Jensen's son Johan Jensen of his father's career and inventions. The second part is a description of a collection of documents from Schleimann-Jensen's career held by Arne Jensen. These documents include patents, news clippings, copies of journal articles authored by Schleimann-Jensen, letters, and photo albums detailing the manufacturing of radio tubes in the 1940's and 1950's.

About the Interview

Johan Schleimann-Jensen: An Interview conducted by Frederik Nebeker, Center for the History of Electrical Engineering, 15 July 1996

Interview #300 for the Center for the History of Electrical Engineering, The Institute of Electrical and Electronics Engineers, Inc.

Copyright Statement

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

Johann Schleimann-Jensen, an oral history conducted in 1996 by Frederik Nebeker, IEEE History Center, New Brunswick, NJ, USA.

Interview

INTERVIEW: JOHANN SCHLEIMANN-JENSEN

INTERVIEWER: FREDERIK NEBEKER

PLACE: Sollentuna, Sweden

DATE: JULY 15, 1996

Johan Schleimann-Jensen (interviewee's father)

Education; radio lab and publication

Nebeker:

I am talking with Mr. Schleimann-Jensen and we are looking at a curriculum vitae. So your father was born in Denmark. In 1906, 27th of July.

Schleimann-Jensen:

Yes, he studied in Copenhagen.

Nebeker:

And you told me before that he actually went to the Polytechnic Laereranstalt, was that right, in Copenhagen?

Schleimann-Jensen:

Yes, he called it the Royal Dane.

Nebeker:

The technical university.

Schleimann-Jensen:

He already had his own laboratory when he was 19 years old. It was his own electron tube laboratory from 1925 to 1935 in Copenhagen. And he helped a Danish electron tube company. I will find the name later. And he was somehow engaged with a monthly popular magazine.

Nebeker:

Was it a technical publication, a radio publication?

Schleimann-Jensen:

It was called Popular Radio. He wrote about some circuit diagrams, telling why and how they will build radios.

Nebeker:

So he was interested in radio as a teenager?

Schleimann-Jensen:

Oh, he was interested in radio from the beginning. He told me a story, his father was a teacher and during the time when my father was a small kid they were taking care of people with problems, alcohol problems. So my father saw a lot of disasters and was very negative about the use of alcohol, that kind of things.

Nebeker:

But his father was very authoritarian?

Schleimann-Jensen:

Yes. So, he told a story that he made agreement with these [inaudible] he would take his father out for a walk and then he would do a tiny hole in the window for it to get the earth inside. And he was digging down his earth plate and then put the wire through the window and into his room, And his father didn't discover it at that time.

Nebeker:

Do you know if he had any friends who were also interested in radio?

Schleimann-Jensen:

I think he had a lot of friends. This was probably a very amazing time for all these people and fortunately we will meet some of the names here. My father was over fifty when I was born, so I saw him in his elder days.

Nebeker:

I was talking just a few days ago to Grenard Pedersen, who was born about the same time as your father.

Schleimann-Jensen:

He is a Swede?

Nebeker:

No, he is Danish. He talked about some friends of his that he had a little group together with. I think he was also born in 1906, but that was Copenhagen or Lexespere.

Schleimann-Jensen:

This is Jutland.

Patents and inventions; weak current engineering

Nebeker:

But at some point he moved to Copenhagen I take it?

Schleimann-Jensen:

Yes.

Nebeker:

I see that was when he went to the technical university.

Schleimann-Jensen:

Then very early he made he made some inventions. He got his first patent when he was 20 years old. I have it here; I found it yesterday. But the most interesting patent he made, I think, was when he was 34 or 35. He took away part of the electron tube, there was a sound in the speaker all the time, and he was the guy who found out how to get rid of that.

Nebeker:

Well, one thing that I know was that these tubes that were plugged into the main circuit often put a 60 hertz or whatever it was signal into the sound system. Was it related to that do you think?

Schleimann-Jensen:

Yes, I have that patent here as well. He collected some articles from that time.

Nebeker:

Maybe before we get into his career here, I have a couple more questions about the early days that you might be able to answer. I know that the Danish technical university was unusual in offering in a weak current engineering as a specialty this early. It had one of maybe the first professorships in essentially radio engineering at a very early stage. Do you remember your father talking at all about the education he got there at the technical university?

Schleimann-Jensen:

Yes, I know that he was so engaged with his own work in his laboratory, but that was related to the school.

Nebeker:

Did he get his degree in weak current engineering?

Schleimann-Jensen:

He never got his degree there. Later on, he was appointed to have some sort of engineering degree. But, I think this laboratory was in fact at the school and he was working with the people there. I am not sure about this. I got the feeling that it was like that.

Philips employment; radio tubes

Nebeker:

Okay. So, he was so successful and doing so well at this that he just did it full time it sounds like. I am sorry, we could look at what you were about to show me.

Schleimann-Jensen:

He did not write this anywhere that I have found, but he told me, because my first work after leaving the Institute of Technology here was at Philips, that company, and he told me when I got that employment that his first employment also was at Philips, and that was after he had made some invention about radio tubes, and after some time at Philips he understood they were not so interested in him. They were interested in the patents. So then he left the company. He didn't see a proper path.

He hasn't mentioned this in here either. But I think this must be in this period.

Nebeker:

Quite early, yes.

Schleimann-Jensen:

And maybe we will find something later. But he met my mother in the early '30s, and she was a Swede. And he wanted to start a factory for these new kind of tubes and he had difficulties in Denmark getting financing. So then, he tried here in Sweden. We had this Leumalampan. It still exists, an organization here in Sweden, a co-operative association.

Nebeker:

Is this for financing?

Schleimann-Jensen:

No. You own part of it and the profits are shared. They owned this factory for making bolts. And it is in south Stockholm. And he went to them because my mother came from Stockholm and said, "Shouldn't you start to make electron tubes?" and they said "Oh yes we are", and he offered his skills, knowledge, and they said they based that on he was competent. Because at this stage as I understood it RCA and Sylvania and all these companies had already started, so they wanted help from them.

Nebeker:

And this was in the early '30s you are talking about?

U.S.; Sylvania employment

Schleimann-Jensen:

Yes, and my father he made a decision, "Okay, if they want to have American knowledge I will get that." So he took the boat. And I found the tickets and a note from that trip. It was in '36 or '37, and he went around knocking at the doors of these companies. And I remember he had told some of these interviewers that they were interested in him because they knew about his patents. And finally Sylvania employed him. They told him that in the United States everybody starts at the bottom.

Nebeker:

And he was married at this time?

Schleimann-Jensen:

No. I don't think so. I don't remember when they married. He worked there and he became manager for a small mounting group, and it got bigger and bigger. After two years at Sylvania they had visitors from Sweden and he was appointed to take care of them.

Lamp manufacturing, tube production

Nebeker:

Had his lamp been manufactured?

Schleimann-Jensen:

Yes. And at this time the cooperative company had sold the lamp factory to Ericsson. So it was Ericsson, and rather soon after this when he showed them around they made this agreement that Leumalampan-- a new company which called themselves Sals Caletrondor would buy it. Ericsson bought license rights from Sylvania. And he was in charge of starting up this production.

Nebeker:

I see. Was he chief engineer for that do you think?

Schleimann-Jensen:

Yes. At the beginning he was the first employee in the company and he was appointed Technical Director. And in 1945 I found yesterday as well he became the Managing Director, and then it was about 400 employees.

Nebeker:

When was it actually started?

Schleimann-Jensen:

'39.

Nebeker:

He was hired, and the company started up right away?

Schleimann-Jensen:

Yes. When he started, it was tough. There were no people working this area in Sweden, so he had to teach everybody how to do this.

Nebeker:

But he started with this lamp manufacturer, is that right?

Schleimann-Jensen:

No, the lamp manufacturer at the same site they were building a new building. It was a separate company from the lamp.

Nebeker:

But I know there were certain similarities in manufacturing technique, so he was able to draw on this.

Schleimann-Jensen:

Yes, I think so. I don't know exactly but maybe we will find out this later as well. I just got through the material to see what should I take and what should I not take, and then we have to read certain parts that interest you.

Nebeker:

It is just that that was a pattern in the early electron tube industry that a lamp manufacturer started a division to do vacuum tubes because they're very similar in production.

Schleimann-Jensen:

Yes I think that was the case here. And of course he got people maybe from there, I don't know about that. But I think those years were very busy for him. When he finally got things going he had to learn about economics and these kind of things as well, and then he became the Managing Director. I found all those papers as well.

World War II and Swedish industry

Nebeker:

Do you know anything about the Swedish radio industry in that period? They must have been importing radio tubes from England or the United States or Germany, and probably when the war broke out they couldn't get shipments of tubes.

Schleimann-Jensen:

I don't know the timing when the war started and when they visited. I think they visited Sylvania in late '38. I don't know if they had the feeling some problems were coming up or if that was the reason. I don't know about that.

Nebeker:

When I talked to this Danish engineer, Gunnar Pedersen, he talked about the great problems in World War II because all the transmitting tubes had been imported from England in Denmark and they couldn't get them, at least once the occupation came. It was just a serious problem. But it is interesting that the timing was before the War that they actually set up this electron tube company, but no doubt the War gave much greater reason to develop this capacity.

Schleimann-Jensen:

He probably he didn't have any problems get financing.

Tube development and lab

Nebeker:

Right, Do you know what type of tubes he began manufacturing?

Schleimann-Jensen:

I am not a tube expert myself, but I think we will find out what kind of tubes he made because there are pictures and there are descriptions for somebody who knows about it. But for me I am not sure about it.

Nebeker:

Okay.

Schleimann-Jensen:

This is a paper he made for the American company TII. He also made surge arrestors because he was engaged as a consultant when he retired. He set up a line for Ericsson for this kind of component. And then my mother died and my father stopped work immediately, and Ericsson tried to get this working after he had left, but they had problems and after two years they sold the whole line to TII. And then TII was contacting our father and he wanted to work again, so he helped them to start it up. And then Ericsson got the new digital switching and they needed a better surge arrestor, and then Ericsson contacted my father again when he was 77 I think, and he said to them, "I plan to be free now, but I can teach my eldest son." That was Arne. He had his own laboratory then, '25-'35. Then he was working with Sylvania in Emporium, Pennsylvania from '36 to '39. He was the Managing Director from the beginning.

At this point I am not sure, but I think he told me that he felt that from the beginning he wanted to set up his own factory in Denmark, but he had problems getting money for it. And now it seems that he was able to build a factory he felt that he should try to do not as big a factory as this but some kind of things for his own to earn some money. So he left the company here and started his own laboratory.

Nebeker:

In 1949.

Schleimann-Jensen:

And I know it employed ten people, and he was developing radio tubes for military applications, high G forces and like that. So he got money from the government. And that was pure research.

Nebeker:

And this is also sub miniature tubes.

Schleimann-Jensen:

And I think in '58 or '59 Philips made some technological breakthrough with these kind of tubes. It was for proximate fuses. So he didn't get money from that point because they could buy.

Nebeker:

They could buy what they needed.

Sylvania position, Mountain View, CA

Schleimann-Jensen:

Yes. Then he had problems what to do and he was contacting his old friends at Sylvania and he immediately got a job there for traveling wave tubes manufacturing in Mountain View, California.

Nebeker:

That is in the Silicon Valley area.

Schleimann-Jensen:

Yes. He became a manager for a development group or something, and in fact we moved over to California, the whole family, and the plan was that we should stay there. I was just three years old and Arne was seventeen, and we moved to Las Altos Hills nearby Palo Alto and we lived there. After one year I think my two elder brothers went home here to Sweden again.

Nebeker:

Well I know they asked about membership in any Communist organization is one thing.

Schleimann-Jensen:

Yes.

Nebeker:

I see. Because they would be a permanent resident of the United States, so Arne would be subject to the draft.

Schleimann-Jensen:

Yes, I think that was the reason why they moved back to Sweden, because they didn't want to join that conflict. And my mother felt very sorry about the family being split up, so after two years she took me and my sister back here to Sweden, and I think this was a disaster for my father. He loved it in California and he had all his friends there.

Svensk Calelectronar, surge arrestor and electron tubes development

Schleimann-Jensen:

So I think it was one year later he came back to the company he had started himself there at Svensk Calelectronar. So one of the guys he employed in the beginning was now the managing director and was his boss. I think that felt a little bit strange for him, but he was appointed to develop this thing.

Nebeker:

The surge arrestor?

Schleimann-Jensen:

Yes.

Nebeker:

In '74.

Schleimann-Jensen:

Yes. It was electron tubes as well, the one you saw there. They were still making electron tubes, and in '67 they put three big Ericsson companies together and started what they call REFA. So since Calectronar is one third of REFA and the activities changed over for substrates and that kind of thing. I know they are moved south in Sweden.

Nebeker:

Is this when your mother died?

Schleimann-Jensen:

Yes, she died in '73. He tried to work a little after that.

Consulting work; Arne Jensen AB company

Nebeker:

Then he started consulting.

Schleimann-Jensen:

Yes, he worked for them and then for Ericsson. And Ericsson wanted TII to develop the surge arrestor to work for the digital switching, but they said we are a producer and we don't want to develop. So I've been told, I don't know. And then Ericsson went for my father and then Arne succeeded with the development and then we started up this factory.

Nebeker:

When was that?

Schleimann-Jensen:

That was '88. This was started by Arne Jensen, AB. That was my brother's company and my father was the first employee there. And in '86 more people came into the business. In '88, when I was with Philips, he managed the Ericsson spec. And then I was working with mass production and I was a manager at Philips, and so I had some more knowledge about how to produce in big quantities. And then I came into the business and we started this subset area.

Nebeker:

And is this also for surge protectors?

Schleimann-Jensen:

This is for surge protectors. This is for leak detection.

Philips, defense program

Nebeker:

You said you were an aeronautical engineer, how did you get into production at Philips?

Schleimann-Jensen:

I was part of the defense program of Philips. We were making smart munitions and I was within the development program for the Swedish defense forces. It was a small target seeker which I had developed . I developed the mechanical things, not the radar parts. We were buying them from another Philips company in England. And it was a target seekers for missiles. Then I became manager for the production of proximity fuses, and that was a coincidence. I did not know that my father had been working with same things.

Nebeker:

Yes, he was making tubes for them.

Schleimann-Jensen:

And we were producing proximity fuses in big quantities, so that was where I went to be in production.

Ericsson work with Arne Jensen; retirement

Nebeker:

I see. What interest did your father take in these two companies?

Schleimann-Jensen:

Nothing. He knew that my brother wanted to get on his own, and when Ericsson asked him about this development and he felt he was too old so he asked Arne if he was interested in learning about this and Arne said yes of course, that could be interesting. So they started in my father's garage, they got some vacuum ovens and that kind of thing from Ericsson, and then they moved the things to my brother's house nearby here, it is just 100 meters, and then my father continued to be retired.

Nebeker:

Okay.

Schleimann-Jensen:

He taught my brother how to do it the old way, how to do the type of surge arrestors that Ericsson was at that moment buying. But then Ericsson needed a better one, and that was made by my brother.

Nebeker:

So your father gradually withdrew from the business.

Schleimann-Jensen:

Yes. He had a lot of plans. He made a lot of tapes and he did a lot of photography and even with movie cameras, and his big project for his retirement was to put all these together in a nice way. Unfortunately he never did that, but he started and he worked with that. But he had saved so much material from all these periods of his life so I think somewhere he didn't know where to start, and it was too much. And I can understand when trying to find things; it is a lot of things.

Health problems

Nebeker:

When did he suffer the stroke?

Schleimann-Jensen:

I think it was 1984. It was three years after Ericsson asked him about this. So that is maybe one reason why he wasn't much involved. He had never seen this facility here. '84 it was, because I bought half my father’s land and was building a house there, and he came down and asked me if I wanted something for lunch and he was driving to buy something in the supermarket, and when he came back from the supermarket it had happened. I could not get in contact with him after that. And one of our neighbors had been behind him in the queue when he had the pain and she had realized that something had happened. And so she called me right after he came home. And he spoke completely normal, but I understood that he couldn't get a word that I was saying. He couldn't understand a word. And then I write on a piece of paper "Can you read?" And he became so angry because I was asking him a foolish question.

Nebeker:

And yet you could speak that question and he couldn't hear you, he wouldn't understand you.

Schleimann-Jensen:

No, he didn't understand what was coming through his ears, but he could read. So I convinced him, it took me one hour, that we had to go to the hospital and he didn't understand why. He just thought that I couldn't speak clear enough so he could understand what I was saying.

Nebeker:

Did he recovery from this?

Schleimann-Jensen:

Yes, two years later he was pretty good and he remembered old religious songs from the church that he had learned when he was very young. Suddenly he remembered them again and he was so happy. But then unfortunately he had another stroke in '86, and nearly the same thing happened. In '88 he was nearly recovered from that one as well but at this stage this was all frustrating for him. You can have two different kinds of strokes, one when the arteries are broken and the other one when it is stopped. At that time he got I think the first two ones was stopped and then he got medication to get the medication to get the blood thinner, and then he got another one with the broken. And he died in 1991.

Discussion of archival materials

Detector tube invention

Nebeker:

Shall we look at some of the clippings you have here?

Schleimann-Jensen:

Yes. This is mainly he had put in when he made his invention to get the tubes not sounding. So he had this kind of motorbike and he was very badly injured when he had some accident in Copenhagen. This one is about his invention.

Nebeker:

I see. I it says here that this new detector tube makes Denmark independent or free of the American patents.

Nebeker:

I don't know much of this history myself but evidently there were some expensive patents that one could license to solve the problem, but his invention...

Schleimann-Jensen:

Yes, maybe it was like that. I have understood from him when he described this that he was the one who found out how to get rid of this. But one thing he was very angry at himself because he didn't ask himself why could it make this noise. How could that piece he took away create this noise? And if he had started to figure that out , that was the same technology as the semiconductor. It was what you call a semiconductor. So he just threw it away and continued to do radio tubes. That's the same invention.

Nebeker:

Professor Pedersen, he was rector of the Technical University. They asked him if he had a chance to acquaint himself with the new invention and Pedersen said yes. I believe it is a matter of some importance.

Schleimann-Jensen:

But he hadn't mentioned that here as well, so I think maybe they were not so interested to hire him but to help him. I think it is the same.

Nebeker:

Well this was obviously a milestone in radio tube.

Schleimann-Jensen:

Yes, a detector tube.

Nebeker:

Yes. Oh this is nice, this Aftenbladet. The 11th October, 1935. And it was demonstrated at the Technical University there.

Schleimann-Jensen:

I don't know if it was this patent that Phillips was interested in.

Radios

Nebeker:

So he supported himself as an independent inventor in those years?

Schleimann-Jensen:

Yes. You see that one, that is one of his earlier radios. That is where you can see KASE, that is Cologne Astremen Jensen I think he had a lot of plans to start a factory.

Nebeker:

Did he actually sell radios?

Schleimann-Jensen:

Yes.

[End of tape 1, side a]

When he started his studies he financed his living by playing the violin.

Nebeker:

Is that right? So, he didn't have really a factory?

Schleimann-Jensen:

No, it was in this laboratory.

Nebeker:

So he sold radios?

Schleimann-Jensen:

Yes, he sold radios to friends.

Patents

Nebeker:

And did he also get royalties from patents, or do you think this was the first patent?

Schleimann-Jensen:

No. I found one from '26. I don't know how important it is. He says here it is the first patent. He was only twenty years old. I don't know if he got licensed when he formed his patents. This is all about the same.

Nebeker:

They seem to be saying that this is a way to avoid a new tube that means you don't have to license an expensive tube.

Schleimann-Jensen:

Yes. We can make some copies of that.

Receiving tubes; government support, press coverage

Nebeker:

I would be interested in that. It says here that in a series of years he had-- he worked with support from the state radio broadcasting agency and they were very interested in his work. This invention was necessary for radio detectors, necessary in building them to pay a substantial license fee, and this invention makes the production independent of foreign patents. And this is a recording in October '35 where he also demonstrated another tube.

Schleimann-Jensen:

Yes but that's probably the one.

Nebeker:

Now, I mean, a problem with those early receiving tubes is that they tended to go into oscillation themselves.

Schleimann-Jensen:

Yes.

Nebeker:

They took very careful adjustment. And so this seems to be that it is a tube that won't do that.

Schleimann-Jensen:

If I understood, but this is a newspaper, you never know.

Nebeker:

As you say, this may be the second tube that had that characteristic. Let me just look back. Well what are the first reports on this invention? That's the 11th of October. Do they say the same thing I wonder?

Schleimann-Jensen:

They are focusing on the American patent.

Nebeker:

Focusing on saving money, which was very important because radio was expensive in those days.

Schleimann-Jensen:

[inaudible] they call it in Danish. We call it shut, which is British.

Nebeker:

Yes. Well this must have been very important to have this many newspaper articles. It says here two new Danish inventions. Let's see if we can figure out what these two are. P.O. Pedersen was there.

Schleimann-Jensen:

You have that skill to read Danish?

Nebeker:

Yes, it is not a problem. I think you are right, there were two things. One was that this is just a feedback tube that is independent of American patents. That is one thing. The other was the non-oscillating tube.

Schleimann-Jensen:

Yes, and that is the one he always mentioned when he talked about this time.

Nebeker:

Big plans.

Schleimann-Jensen:

I thought so too.

Marketing

Nebeker:

It sounds like it was characteristics of your father to always have big plans. And his plans were to market this tube, is that right?

Schleimann-Jensen:

Yes, first for radio.

Nebeker:

It is under production at the moment and will presumably already in the course of a couple of weeks be ready to be put on the market. Negotiations are in process. You were telling me that he had trouble raising money in Denmark.

Schleimann-Jensen:

Oh, that is a guess from my side. But there is something that is strange here. I think it should be '37 there.

Nebeker:

Yes, this one should be '37.

Schleimann-Jensen:

I found some letters when he was writing to this cooperative organization, which is a very big one here in Sweden.

Nebeker:

Yes. And that was to run this branch of the lamp manufacturer; it wasn't to set up his own company is that right?

Schleimann-Jensen:

I think he understood that if he should succeed here he'd need more money than he was saving to raise himself.

Laboratory; Ericsson

Nebeker:

So this was made in 1948 when he left or maybe it was '49.

Schleimann-Jensen:

To start up his own laboratory. So here is a lot of photographs, and here is where I saw that he became the managing director in '45. When the company Svensk Electron was founded on the 8th of December 1938, and I saw somewhere that the visitors were at Sylvania in November, so things went there quickly.

Nebeker:

It goes to '39 according to this card his appointment.

Schleimann-Jensen:

I found a check from Ericsson to him that should cover his cost to move and all that, and that is taken in Spring '39.

Nebeker:

Okay.

Schleimann-Jensen:

To start electron tubes manufacturing it was needed to build up from the beginning. Completely new company, task which was everything else than the EC, then technical people with experience from this special area, this was not available in Sweden and the connections abroad were cut off because of the War. They gave the task to Arneis I guess and he was called in as the technical director to lead the company. From 1945 he has completed his service as the managing director. Then, after one decade with the company, he left at the end of' 48. He put together this album to show what has grown up under his leadership.

Nebeker:

That was the citation just inside this book.

Schleimann-Jensen:

Then somebody [inaudible] engineer.

Nebeker:

Production engineer?

Schleimann-Jensen:

Production engineer, yes. That was the Swedish word.

Nebeker:

Okay.

Schleimann-Jensen:

So I don't know the names of them. It's a lot of people here in the beginning.

Electron production album, employees

Nebeker:

We have the photographs of all the people or many of the people who worked there.

Schleimann-Jensen:

Machine engineer, what do you call it?

Nebeker:

I don't know it may be efficiency engineer.

Schleimann-Jensen:

Here is some of the machinery and how they are, yes you see these are [inaudible] pressing machines, see the [inaudible] cooling the press.

Nebeker:

Yes.

Schleimann-Jensen:

And he was making cathodes, and these ladies are helping him, thin wire, and he is a coordinator.

Nebeker:

Do you know how many people were employed in the company when he left it?

Schleimann-Jensen:

Six hundred. I say it is obviously something that is very clear for everybody, something that was you need to do these tubes, which was no need to explain.

Nebeker:

Re-evacuating the tubes probably, the grid.

Schleimann-Jensen:

Yes, the grid and the spacing and the thickness was all very important on those grids. It is experiments for new types. He is thinking of how to join the materials. It is a lot of his process. I don't know how familiar you are with all this.

Nebeker:

No I am not familiar, I am just taking a quick look here. I want to say for the tape that this album has probably 50 or 100 or more very high quality photographs showing electron tube production in 1948, so if someone wanted to document how tubes were made you can see much of the equipment here and the people working at the equipment. This is a very good record of one company at that time.

Schleimann-Jensen:

Especially tubes manufactured here in this department, the report for that.

Nebeker:

It was a very nice gesture for your father to put together an album like this, and it is wonderful how it documents what was going on in that factory.

Schleimann-Jensen:

They were working with microwaves as well.

Nebeker:

There is a wave guide.

Schleimann-Jensen:

And there is Sontig Javer. He became his boss when he came back.

This is '54. Maybe he had his laboratory on a smaller scale between '54 and '59. I found that in one of these boxes here. This is a special tube for high G forces.

IRE Anniversary Banquet photograph, 1948

Nebeker:

This smaller book also has a lot of photos of people at work making these tiny tubes. We are looking at a very large photograph of the 36th Anniversary Banquet at the IRE. I see it is in March, 24th 1948 at the Hotel Commodore, probably New York. Your father was awarded his IRE Fellow rank in 1948.

Schleimann-Jensen:

Yes, and at the same time as William Hewlett and David Packard. I think they were all on the same table here. I don't know, but here is my father. He had a thing that you could put over here with all the guests and then you could read that but I don't find it now but somewhere it is. I think he told me that they are there.

Nebeker:

Is this your father here?

Schleimann-Jensen:

Yes. So if you recognize the faces of Hewlett and Packard, they are probably guests.

Nebeker:

I think this is John Pierce right here at the same table as your father, a famous engineer. I don't see Hewlett or Packard, but I probably wouldn't recognize them.

Elementary school science text

Schleimann-Jensen:

And then the rest it is the best for me to not make a bigger disorder here. Just go and see something of interest. And then we can make copies of them. Now this is just for fun. I found one of his school books he had when he was very young.

Nebeker:

And this is his own drawing?

Schleimann-Jensen:

Yes. I thought it was fun to see it.

Nebeker:

But this is a science book, elementary school, 1893, Fahrschnitt.

Schleimann-Jensen:

I wonder what they are doing here?

Nebeker:

Well, this may be where your father started with electricity.

Schleimann-Jensen:

No, he has done something else here. I was very happy when I saw this because I made the same.

Nebeker:

This was his station.

Schleimann-Jensen:

Yes.

Nebeker:

It was amateur radio.

Schleimann-Jensen:

And it is a lot of these books when he [inaudible passage]. I think this was when my mother had died and then he agreed to stay for a couple of months and they made this arrangement for a short period. It was for Ericsson. His books, there is a lot of these.

Semiconductor publication; amateur radio publication

Nebeker:

Let me just put this on the tape. It is a Proceeding of the IRE, August of '59, an experiment indicating generation of sub-millimeter waves by avalanching semiconductors. Well this is an early semiconductor device.

Schleimann-Jensen:

Now this I found, I haven't got time to look through it, just some guy in Denmark that sent things that they thought would interest my father, and it is late 85.

Nebeker:

An amateur radio publication. It's the 75th Anniversary of amateur radio. So this is a Danish amateur radio publication, and of course your father was Danish.

Schleimann-Jensen:

Here was that word I saw. He had made a copy of something that was made August '35.

Nebeker:

Okay.

Schleimann-Jensen:

Maybe it is just this description of this invention.

Nebeker:

Was his laboratory being supported by this company?

Schleimann-Jensen:

I don't know the relationship yet.

Nebeker:

It sounds like it here, right?

Schleimann-Jensen:

Yes.

Nebeker:

The new valve development in Denmark this is Wireless World, OK. November 8th, 1935 there's an article in Wireless World on this tube called the renode.

Schleimann-Jensen:

Here is some more about that guy. I don't know much about him.

Nebeker:

If I could get copies of these pages that would be very good. And here's a German publication from October '35, so it was immediately getting press in other countries.

Schleimann-Jensen:

Yes, make copies of this.

Tube manufacturing

Nebeker:

This is a copy of some protocol from the 12th of October, 1942 and he is talking about, well, this is the tube manufacturer. OK, here we see...

Schleimann-Jensen:

They have only manufactured 1,600 tubes per day.

Nebeker:

So they are trying to get their production up from 1600 tubes a day to 2600 tubes a day.

Schleimann-Jensen:

Obviously they had 39 percent scrap, so they had a lot of trouble.

Nebeker:

Now, this is the very beginning or the first years of tube manufacturing in Sweden, so in all the problems I am sure of getting the right materials and training people and so on.

Schleimann-Jensen:

This is meeting notes from all the meetings.

Nebeker:

Maybe what we can do is if you take a sample, you know, like the front page of a couple of these, and then we would know that such records exist if somebody is really doing research on history of tube production and then they could know where these are.

Schleimann-Jensen:

Yes I could do that.

Nebeker:

If you take maybe just a couple of those front pages and...

Schleimann-Jensen:

This is when this company which he started, Svensk Electronar became Leha. That is in '67, and he was with a company at that time and he was working with surge arrestors. And here is something from Ericsson about their tubes. this is from the '60s I think.

Nebeker:

And your father was involved in that particular tube, that long line tube?

Schleimann-Jensen:

Yes, I think so. And he was working both with the surge arrestor and these tubes I think, and his responsibility was to develop these kind of things at that time.

Nebeker:

Did he develop this kind of, this framed grid tube, is that what it was called?

Schleimann-Jensen:

I don't know about that, but he was involved in the manufacture of it anyway. The frame grid.

Nebeker:

Sometimes in advertising literature they tend to exaggerate.

Schleimann-Jensen:

It was the same company when it developed a little bit. I think this is the same. I don't know if you are interested in this here. Maybe you can take one.

Nebeker:

I would be very happy to, if you want to part with one of those.

Schleimann-Jensen:

Don't they look the same?

Nebeker:

Yes.

Schleimann-Jensen:

I think I have found some more in another box so you can take that.

Nebeker:

Thank you.

Schleimann-Jensen:

Transistors. He was not working with those sort of things, not that I heard of anyhow. And this is the same all these. Then we were back to the first. I am worried about the time now because there are a lot more boxes.

Personal letters

Nebeker:

So in this entire period that he was in the United States he was writing letters to his parents, and you have here all the letters. It is probably a very good record then for work at Sylvania, what was that, special tube department? I've forgotten what it is.

So he was working for Sylvania in these years in Emporium, Pennsylvania. We have some record here.

Triode patent

Schleimann-Jensen:

Yes. Here is a patent for his triode, or what do you call it?

Nebeker:

Yes, triode. It is a field emission triode or it was a patent for manufacturing techniques.

Schleimann-Jensen:

Yes, how to manufacture a triode with field emission. With such a triode it says, but maybe he used a triode in the production, but I don't know.

Nebeker:

But you said that he tried to raise money for this and evidently didn't succeed and then took that job in the United States.

Schleimann-Jensen:

At Sylvania the second time, yes.

Electron tubes manufacturing publication, 1941

Nebeker:

We have here a publication, 1941.

Schleimann-Jensen:

Yes it is how to manufacture electron tubes, and it is when he was with Svensk Electronar.

Nebeker:

Yes, very early in that time.

Schleimann-Jensen:

It is published in this magazine, Technique [inaudible], 1941. So I think I have a lot of these but they are in Swedish. You can take one of these.

Nebeker:

I'd very much like one.

Schleimann-Jensen:

There are some pictures.

Nebeker:

They even have pictures of exactly how they are manufactured. It is impressive that they would publish this information.

Schleimann-Jensen:

I think so too. I am a little bit surprised. 1941 is only two years after they started.

Nebeker:

Well maybe they were even hoping that other companies would get into the business to meet the demands in the War.

Schleimann-Jensen:

Maybe.

Nebeker:

Was your father was very theoretically informed, if his design work was heavily based on theory.

Schleimann-Jensen:

I think a lot of the work was based on theory, but he was also very practical so he made a lot of trial and error I think. And I think we have here in this one notes that he had made. I saw it in these books I found this morning.

[End of interview]