Oral-History:Ralph M. Showers

About Ralph M. Showers

Electromagnetic pioneer Ralph M. Showers recalls a childhood fascination with electronics, specifically trains. Born in Plainfield, New Jersey in 1918, his family relocated to Philadelphia, Pennsylvania at the age of two . Upon graduating high school in 1935, Showers enrolled at the University of Pennsylvania, graduating four years later with a degree in electrical engineering.

Showers remembers collegiate teaching as his initial aspiration, yet life in a new, enigmatic field would not prove so neat. Soon, he found himself conducting research during World War II, and briefly working for General Electric. During the war Showers worked on communications systems in the radio interference business. Located in the now famous Moore School, where scientists were working seemingly around the clock on the development of ENIAC, fears of enemy access consumed the environment under which Showers worked during the war. Additionally, while performing this work for the government, he continued to work towards completion of his PhD as well. His PhD examined the measurements of resistance for high frequencies. Showers also worked for the Interference Reduction Panel of the Research and Development Board, while completing his doctorate. Before completing the PhD, the University of Pennsylvania hired Showers as an assistant professor.

From 1955-7 Showers chaired the IRE’s Committee 27 Radio Frequency Interference, a group aimed toward standardizing the measurements of radio interference. Throughout his career he has seen concerns transform and become more sophisticated as the field of electronics itself has become more advanced. In addition to the level of sophistication, Showers also views globalization as a major influence on electromagnetics. After World War II, exchanges across the Atlantic increased. Eventually in the 1970s, Europeans and American divided up work in the electromagnetic field. Each concentrated on different problems.

In recent years, even though standardizing the electromagnetic field has become internationalized, ironically, it is a lack of cooperation by the military, which was indispensable to early development, which represents major obstacle. Organizations like NATO have their own standards, which do not necessarily coincide with the IEEE. Asian countries are also much more involved in the process of standardizing the field. The establishment of the European Union and their excitement regarding electromagnetic funding is further evidence of the international effort. Technological developments like personal computers and cell phones have required those in the field to rewrite new standards, both in Europe and the United States. Energy efficiency is also a main concern for pioneers like Showers, who estimates that standardizing global methods could cost as much as $50 billion to correct worldwide. Concerns aside, Showers feels that the field has moved in a positive direction and will continue to do so.

About the Interview

RALPH M. SHOWERS: An Interview Conducted by Frederik Nebeker, IEEE History Center, 3 December 2003

Interview #429 for the IEEE History Center, The Institute of Electrical and Electronics Engineers, Inc.

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

Ralph M. Showers, an oral history conducted in 2003 by Frederik Nebeker, IEEE History Center, New Brunswick, NJ, USA.

Interview

Interview: Ralph M. Showers

Interviewer: Frederik Nebeker

Date: 3 December 2003

Place: Philadelphia, Pennsylvania

Family and educational background

Nebeker:

You were born in Plainfield, New Jersey in 1918. Would you tell me a little about your family?

Showers:

My dad and mother both went to [unintelligible] University in [unintelligible]. I think my father was in social studies. He ended up preparing for the ministry. He went to a church in New York City. I don't remember the name of it.

Nebeker:

What denomination was it?

Showers:

It was Protestant. I'm sorry. I can't remember.

Nebeker:

We can put that in later.

Showers:

Yes. And then he decided he didn't want the ministry and went into teaching. During the war he worked at manufacturing plants, but I think the thing that took him Plainfield was a teaching position.

Nebeker:

At what institution did he teach in Plainfield?

Showers:

I cannot remember. I was born in 1918 shortly after the end of World War I. I think he moved to Philadelphia in 1920. He got a position in the Philadelphia school system. He may have only worked in the manufacturing plant prior to that.

Nebeker:

Did you grow up in Philadelphia?

Showers:

Yes.

Nebeker:

Were you interested in science and technology as a boy?

Showers:

That's a good question. Yes, certainly. I was interested in electrical toys – trains and things like that.

Nebeker:

Did you have a crystal radio set?

Showers:

In high school I had some very good friends that were working in radio amateur. In fact I built a crystal radio set and was a radio amateur for a while.

Nebeker:

Did you have your own transmitter?

Showers:

Yes. All that ended when World War II came along.

Nebeker:

You were about twenty or twenty-one when the war broke out in Europe.

Showers:

Yes, that's right.

Undergraduate and graduate studies

Nebeker:

I know you went to the University of Pennsylvania. Did you go straight from high school to the university?

Showers:

Yes.

Nebeker:

Did the war disrupt your education?

Showers:

No, not really. I started in 1935, graduated in 1939 and stayed on for graduate work. After the war started I was doing research here at the university for a period.

Nebeker:

Did you get an electrical engineering degree?

Showers:

Yes.

Nebeker:

What was your intention when you started your education? What did you plan to do with your degree?

Showers:

Get a job.

Nebeker:

As an electrical engineer?

Showers:

Yes.

Nebeker:

You planned to get a bachelor's degree and then go to work?

Showers:

Yes. But before I graduated I was pretty well convinced to go on for graduate work.

Nebeker:

Was there a teacher here who particularly influenced you?

Showers:

Yes. Irvin Travis was very intelligent. And then there were two others. Carl Chambers who later became dean of the school, and Dr. S. Reed Boring also influenced me.

Nebeker:

Into what field of electrical engineering did you go for graduate work?

Showers:

I took a pretty general course at first and then I got into the communications school.

Nebeker:

Did they have an electronics or communications option at the time for undergraduates?

Showers:

No. I think it was general EE course. There were a number of electives, but when I was an undergraduate there were not a lot of choices like there are today. I think it was pretty general.

Nebeker:

When you went into graduate work was that in communications?

Showers:

Yes.

Communications systems research at the U. of Penn.

Nebeker:

What was your thought at the time? Did you plan to go on for a Ph.D.?

Showers:

That was always in the back of my mind. At the end of my graduate year I took a job in Schenectady. I was there for about five months.

Nebeker:

At General Electric?

Showers:

General Electric. Then I was offered a job back here on the campus.

Nebeker:

Was this after one year of graduate work?

Showers:

Yes. I decided the future looked better and more interesting on campus.

Nebeker:

Did you hope to go into teaching college?

Showers:

Yes.

Nebeker:

Was the job here in research?

Showers:

It was research. Yes.

Nebeker:

With whom did you work for that research?

Showers:

Dr. Warren [unintelligible]. That was my first job here. He was doing X-ray measurements. Then I got involved with a war joint research project doing special communications work with Dr. Chambers. We continued with that until almost the end of the year, and the end of the year [unintelligible] end of the war. Just before the end of the war we got involved in a contract in the radio interference business. That is where my career started.

Nebeker:

Can you tell me about the communication system on which you worked during the war?

Showers:

I do not want to say too much. It was short distance communications and I worked on induction fields.

Nebeker:

Was this for field communications?

Showers:

For use in the Army, especially in places where vision was difficult.

Nebeker:

Was it a walkie-talkie sort of system?

Showers:

Yes, but shorter range than a walkie-talkie.

Nebeker:

Did that research lead to any military equipment?

Showers:

Actually not. I took a trip to western Mississippi to show off this equipment as well as some other equipment, but the war was over shortly after I made that trip. The war was over in 1945 and I made that trip in the spring of 1945. By that time they were not interested in the basic thing that I was [unintelligible]. They were out of [unintelligible.]

Nebeker:

I see. Were you physically in this building of the Moore School during the war years?

Showers:

Yes.

ENIAC and the Moore School research environment

Nebeker:

Were you aware of the work on the ENIAC here?

Showers:

Oh yes. Very much.

Nebeker:

Was it down the hall or on a different floor?

Showers:

There was not too much space around here.

Nebeker:

It's not a huge building.

Showers:

While they were building the ENIAC I was working with antennas, taking it to the [unintelligible]. We were doing some theoretical work in the antenna field. That's old hat now, but in those days it was new work. In fact, the ENIAC came out of that, because one of the persons I was working with was John Mauchly. He was doing computations of missile flight paths, and he was doing numerical integration of flight path equations. There were rooms full of mechanical computers.

Nebeker:

Desk calculator sorts of things?

Showers:

Yes. One of the things that I think inspired him to develop the ENIAC was that it could be done so much more quickly and simply electronically than mechanically. Mauchly spent a lost of his time keeping his machines maintained and repaired.

Nebeker:

How would you describe the atmosphere at the Moore School during the war years? Did it seem like an exciting place to be because of the nature of the work being done there?

Showers:

Oh yes. There was a lot going on and a lot of people involved. I would say it was an interesting place to be.

Radio interference research and Ph.D. research

Nebeker:

Then you got into radio interference work right after the war?

Showers:

Yes.

Nebeker:

How did that happen?

Showers:

I don't really know. Dr. Chambers arranged the initial contract.

Nebeker:

Was this a military research project?

Showers:

Yes. It was with the Navy, and it started a relationship that lasted a long time. At that time they were mostly interested in developing measuring equipment.

Nebeker:

To measure what?

Showers:

Radio interference. There were a couple of commercial versions available but they had some contracts to build instruments that extended up in the higher frequencies. In those days the broadcast band was a typical frequency range, but there was a lot of interest in extending into higher frequencies, because military equipment was using higher frequencies.

Nebeker:

You worked on equipment to measure radio waves?

Showers:

Well, the problem is this. All electrical stuff, especially mechanical equipment, produces disturbances in the radio frequency range. These interfere with stereo standard broadcasting and all kinds of communications. The main problem with which we were concerned at the time was instrumentation discernment – how to design the instruments, with what characteristics, types of amplifiers, bandwidth of the circuits used and the detectors used.

Nebeker:

Was this because the Navy was having problems with interference with equipment on their ships?

Showers:

Yes.

Nebeker:

Did they want to have portable meters to measure interference?

Showers:

They needed portable equipment to make measurements shipboard, but they also needed standardized equipment used in laboratories to make sure that the equipment they were buying was not producing an excessive amount of interference.

Nebeker:

I see. They were testing the equipment they were buying in the laboratory for interference.

Showers:

Yes. The question was how to make the tests, what circuits to use and which instruments to use make the tests.

Nebeker:

Was the idea that the Navy would define allowable interference and then the manufacturers would produce to a specification?

Showers:

Basically that is what it was.

Nebeker:

Of course they had to have a standard means of measuring the interference.

Showers:

Yes. And they had to deal with both conducted and radiated interference. If connected to a power line, interference is sent down the power line. It also radiated interference, and that had to be measured with antennas that had adequate sensitivity.

Nebeker:

Was there also an effort at that time to determine the susceptibility of equipment to interference?

Showers:

Yes, that was an important problem. At first it was not as important as the emission problem. I think that it was during this phase just after World War II that the measurements of immunity became of concern. I am not really sure, but the Air Force was a prime leader in developing immunity characteristics. I think they had a whole set of requirements for [unintelligible] by 1960.

Nebeker:

Had Dr. Chambers been involved with radio interference before this project?

Showers:

No. I don't know how he got the contract.

Nebeker:

You worked as a researcher on this project while you continued to work for your degree; is that right?

Showers:

Yes.

Nebeker:

Was this also your Ph.D. work?

Showers:

Certainly my Ph.D. was related to this and stemmed from the work I was doing in the laboratory, but my Ph.D. was on measurements of resistance for high frequencies.

Nebeker:

In 1945 you were already a consultant to the Interference Reduction Panel of the Research and Development Board. Was that an inter-service effort to address these problems?

Showers:

It was the militaries. Yes.

Nebeker:

Did they try to coordinate the work that the different branches of the military were doing on this project?

Showers:

You are going back a long way. I have completely forgotten about that.

Nebeker:

You don't have to answer every question.

Showers:

I think that was its purpose basically, to find out what had to be done. It was a joint service effort.

Post-doctoral employment and electromagnetic compatibility research at the Univ. of Penn.

Nebeker:

You completed your Ph.D. in 1950. Were you doing any teaching during the time that you were working on your Ph.D.?

Showers:

I had a laboratory and was teaching undergraduate laboratory. A new laboratory had just been built. This floor on the building has just been built. When I first came here this building had only two stories. They built this floor to accommodate research work, but they also put an undergraduate laboratory on this floor. I had a lot to do with setting up that laboratory.

Nebeker:

After then you got a faculty position here after you got your Ph.D.?

Showers:

I had the faculty position before I graduated. I was an instructor or maybe an assistant professor until I got my Ph.D.

Nebeker:

Were you with the conditions here and your ability to do research and so on?

Showers:

I thought was anyway.

Nebeker:

Now we are up to 1950 or so. What were your research interests in those subsequent years?

Showers:

I continued in the same area.

Nebeker:

Did this include the development of instrumentation?

Showers:

I worked in the general field of electromagnetic compatibility. I also did a large number of contracts, some having to do with semiconductors as they became [inaudible]. The semiconductor work was a contract with the Army. I had a couple of contracts with NASA for interference studies.

Nebeker:

Was the goal of these studies typically to determine susceptibility to different types of interference of given equipment?

Showers:

One of the NASA contracts was writing a handbook on the general subject of [unintelligible]. I also did a contract with NASA on techniques above a gigahertz – the phenomena and what can be done with it and what are its applications.

Nebeker:

Would you tell me a little about the field of electromagnetic compatibility around 1950 and the early fifties? Were there many people who decided to work in this field?

Showers:

I do not think there were many outside of the military. The Army, Navy and Air Force had their own groups that were working in it at that point.

Nebeker:

I learned about the Fort Monmouth group from Warren Kesselman.

Showers:

Right. They had been active many years before that, though I cannot put a good finger on time spans. There was a fellow at Purdue University who built what we call an impulse generator. The impulse has the characteristic that it radiates at broadband frequencies. If built carefully enough, it puts out what is called a standard interference pulse.

Nebeker:

Is this supposed to be fairly flat across frequencies?

Showers:

It is flat. That was one of the early developments in obtaining a standard for measurement. It may still be used as a reference standard. I have sort of lost contact with the field, so I don't know the extent to which it is actually being used now. But it was a very basic development at the time.

Nebeker:

The military groups were interested in this and a few of you at universities. Were any of the large companies like RCA or GE were working in this field?

Showers:

I think those companies had to meet the requirements, but the instruments were not built by larger companies. One of the first was built by Ferris Instruments.

Nebeker:

Did you ever get involved in the business side of things?

IRE and Electromagnetic Compatibility Society

Showers:

No. Empire Devices also built an instrument.

Nebeker:

Where did you publish your research results in the fifties?

Showers:

Let me see. When did we start the Electromagnetic Compatibility Society?

Nebeker:

That must have been in the mid-fifties, 1956 or something like that. Perhaps the Proceedings of the IRE.

Showers:

Yes. IRE Proceedings. I don't know. We only had about one or two papers I think.

Nebeker:

I guess there was no society that had these interests until that professional group was formed.

Showers:

That's right.

Nebeker:

Was the IRE important to you personally? Did you go to meetings?

Showers:

Yes, I got involved in their standards work. There was a fellow from GE whose name I think was Shea, and I think he was responsible for setting up a committee in IRE to standardize the measurements of radio interference.

Roles of IRE and military in radio frequency interference standardization

Nebeker:

Your Fellows biography reflects that you were chairman of Committee 27 Radio Frequency Interference of the IRE from 1955 to 1957. Is that the standards committee to which you are referring?

Showers:

Yes, I think so.

Nebeker:

And that was to standardize instrumentation?

Showers:

Yes, instrumentation and measurement techniques.

Nebeker:

This was to specify how the data indicating interference would be generated?

Showers:

To measure the level of the interference being produced.

Nebeker:

Was there a lot of involvement of the military in that standardization effort?

Showers:

Yes, I think there were. I will have to go back and look at the title. The military had their own groups working on standards. I don't know when the original standard 461 first appeared.

Nebeker:

Was there a perceived division in the field between military and civilian workers or interests?

Showers:

Yes. Of course the military were often working in a classified environment, and the types of devices that caused them trouble were not necessarily the same as what caused trouble in civilian instruments.

Contracts and military funding

Nebeker:

You mentioned some contracts with NASA and the Army in your own work. In those early years were you mainly concerned with the military difficulties?

Showers:

Most of the source of funds was military at that time. We had very little if any commercial funding. I should add that one of the first interference standards produced by a civilian committee was for military use. It was called JANI-225. That was developed by ANSI Committee C63. I cannot remember when that was formed. I am a little uncertain at this point of who did what when, but there were military people involved in that work. There was close coordination between the civilian and military in that. What happened then was that the Air Force – I think it was the Air Force – went out on its own and developed its own standard. From that time until recently the military was quite separated from the civilian [unintelligible word(s)].

Military security and publication

Nebeker:

The Air Force people did not typically publish their research in the open literature?

Showers:

I think that is true. Let's be careful. When you say "in the open literature" you include conferences. We had a whole [unintelligible word(s)] of military conferences for a while, continuing even after the EMC Society was formed.

Nebeker:

Was security clearance required to attend those conferences?

Showers:

Yes, but the Proceedings are up there on the shelf.

Nebeker:

And they were widely available?

Showers:

Yes. Widely available.

Nebeker:

I see. The research community was fairly open.

Showers:

Yes. If you include those Proceedings of the conferences, that was where many of my papers were published. Not under the IRE as such. After the EMC Society was formed then of course [unintelligible phrase].

Semiconductor materials research

Nebeker:

Would you tell me a little about the investigation you did of semiconductor materials in the late fifties? What was the objective?

Showers:

The objective was mostly to identify rectifying materials. There were a couple of other people involved that were really the experts in that area. I basically managed the effort.

Nebeker:

That had nothing to do with electromagnetic compatibility?

Showers:

No, it did not have anything to do with that. It was a minimal effort.

Nebeker:

What about the research project, "Studies of electromagnetic compatibility of equipments and systems for the Bureau of Ships from 1960-68"? What was that specifically?

Showers:

It enabled us to do a variety of things that were of interest in developing measurement techniques. We were generally concerned with the ship as a system and how interference from any one of the systems could be avoided. We were particularly concerned with [unintelligible word] patterns and the effects of high-intensity radiation. It was unstructured in some [unintelligible phrase] on the system. There were a lot of things done under that title – characteristics of the installation, shielding effectiveness and special instrumentation requirements to account for [unintelligible phrase].

Nebeker:

You were very much involved with developing new measuring techniques.

Showers:

Yes.

Graduate student researchers

Nebeker:

It appears that you had quite a few people working under you on these contracts over the years while you also oversaw students who were doing master's and doctoral degrees. That seems to be a real benefit of a position like yours, that you have been able to direct the work of many people that way.

Showers:

Those people were a resource. They were students who came here to work on graduate degrees get support.

Nebeker:

They would get a research assistantship because you had these grants?

Showers:

Yes.

Radio interference research as an international field in the 1950s and 1960s

Nebeker:

How would you characterize this field in the fifties and sixties as a whole? Is that possible?

Showers:

Certainly it was a period in which the field blossomed. No question about it. The frequency range in the instrumentation was extended up to a gigahertz. There was very intense standards activity during that period, developing the standards for measurements. Incidentally, the Europeans got interested in this field at the same time. Since 1934 we had a committee known as the International Special Committee on Radio Interference (CISPR). The mechanism for setting up that committee was started in 1934. It met once or twice before the war, and then nothing happened until the 1950s. CISPR had a meeting in 1955. The first CISPR meeting I attended was in 1958. That was exclusively for radio. Then in 1970 or 1974 the committee in the International Electrotechnical Commission (IEC) was formed. CISPR was related to the IEC, but it was a separate organization. The International Electrotechnical Commission set up a committee on electromagnetic compatibility that was primarily concerned with phenomena at low frequencies below the radio frequency range.

Nebeker:

What were the problems or concerns there?

Showers:

I would call it power quality. One of the problems is with the development of electronics. When a device is connected to a power line, the power line is alternating current while the device is electronic and works on direct current. Therefore the AC and DC must be rectified. That process generates harmonics of the frequency. For example 60 hertz generates a complement [correct word?] of current of 120, 180 and 240. Thus, high levels of higher-frequency currents are carried in the power line.

Nebeker:

Do the high levels of higher-frequency currents cause problems in equipment?

Showers:

The battle is still being fought that debates the severity of the problem. The Europeans have developed requirements limiting the higher-level [correct word?] flow. U.S. scientists do not think there is much of a problem in this country. In Europe they think it is a big problem.

Nebeker:

And who is right?

Showers:

We are both right.

Nebeker:

That's a diplomatic answer.

Showers:

The issue is a matter of cost. The costs associated with these phenomena are considered by the Europeans to be important. In the United States we recognize it as a problem that arises under certain conditions, but it is not seen as a general problem. Another issue is when you throw a switch for a large motor the result is a voltage surge. And the question is, is that of any consequence? You get flickering lights. There are a lot of people concerned with that kind of thing. No regulations exist.

Nebeker:

To what extent was there exchange across the Atlantic from the sixties and onward on such issues?

Showers:

Quite a lot. The U.S. has been active in the international scene since about 1955.

Nebeker:

Has there been a research effort in Europe since the fifties?

Showers:

I think the answer is yes. I do not know how much of it was sponsored research or the internal research of companies.

Nebeker:

Were people who were working in this field in this country often reading European publications or looking at European equipment that had been developed?

Showers:

The equipment was pretty [unintelligible word(s)]. Instruments were developed in the United States early on.

Nebeker:

Were the Europeans were using the instruments that had been developed in this country in the fifties and sixties?

Showers:

It's possible. I do not know of any European instruments. Let's put it that way.

Nebeker:

Okay. But there was good exchange of information across the Atlantic; is that right?

Showers:

Yes, after the war.

International electromagnetic compatibility committees in the 1970s

Nebeker:

And how did that go after the international electromagnetic compatibility committee was set up back in 1970 or 1974?

Showers:

Well, the original committee was the CISPR. Then the TC-77 was set up. There were jurisdictional questions over who was doing what to whom, and the problem was to try to keep them separated. I thought it was an advantage to keep them separated. There were people in Europe that were willing combine the two of them.

Nebeker:

Was there a way to divide the work clearly?

Showers:

It was finally divided. The division of the work was primarily that CISPR was interested in radio interference, which is mostly an emission phenomena, and the immunity issues were not dealt with by— [tape turned over; sentenced not finished; beginning of next sentence also not recorded]. ...emissions below 9 kilohertz, which is kind of a dividing line between radio frequency and non-radio frequency. TC-77 was also interested in immunity as such. There were other differences in the committee but those are the main differences between TC-77 and CISPR. There is also a difference in their organization – who they report to and so forth.

Nebeker:

One was within the International Electrotechnical Commission?

Showers:

One is strictly organized within the International Electrotechnical Commission. CISPR is, to a large extent, supported by the International Electrotechnical Commission, but it has its own government body and that makes it a little different.

Nebeker:

Are these both international organizations?

Showers:

Yes.

Nebeker:

Are Asian countries represented as well?

Showers:

Oh yes.

Nebeker:

Has it been possible to reach agreement on standards worldwide on these issues in general?

Showers:

Oh yes. Yes. TC-77 has something like 34 standards at this point. They are not all finished, but they are scheduled. CISPR is divided differently, but it has a lesser number of standards. It's up to publication 22. Well, it's almost the same number now that I think of it.

International civilian and military cooperation on standards

Nebeker:

Would you see this as an example of successful international cooperation on such an issue?

Showers:

Yes, generally. It's true. The place where we really have not succeeded in getting real cooperation is between the military and the civilians. In the military, NATO uses a lot of the standards that the U.S. military uses. NATO may have some of its own standards too. But there are differences in the military's requirements. We recently tried to get more common use and measurement techniques and so on. My feeling is that these are differences of opinion, the standards of measurement. It can be measured like this or it can be measured like that. However the problems are somewhat different, because the military deals mostly with equipment on platforms. That metal structure is not there in civilian use. There are buildings and so on that do not have the same electrical configuration. Therefore the measurements technically appear to be different.

Nebeker:

I can easily understand that the military would have concerns of a different sort and maybe of a different intensity than civilian work, but it is not clear to me why measurement techniques would be different in the two realms.

Showers:

The instrumentation is not that different. The measurement technique is different due to the fact that in the military the equipment being measured is sitting on a metal plane. This is not the case in civilian sphere there is something is for instance on a desk. Where is the ground plane? It is not the floor, unless there is reinforced steel on the floor.

Nebeker:

I see. The instrumentation is fairly uniform, but the way measurements are done is different in the two spheres.

Showers:

Right.

Nebeker:

Then there are necessarily different standards.

Showers:

They have different limits.

Nebeker:

Is this a result of the reality of the situation or might it have been different? Might have the field have evolved with a more uniform system of measurement?

Showers:

This is a very complex subject. A configuration from an electrical point of view is very complex that has systems with many different devices in them. How is something as complex as that measured in such a way that gives a unique characteristic? It is very difficult. The installation of the device must be simulated as realistically as possible. I have always said that you if have a device, it has certain radiating characteristics, it has certain conducting interference characteristics. That should be measured uniquely. But the problem is that the systems are so complicated that it cannot be done. It is dependent on anything [unintelligible word(s)], it is dependent on how cables are run, how many units are in the system. A computer system may have twenty cabinets in it. How do you measure it? If groups were really interested in cooperating with each other these could be made common. We made a comparative study of military and civilian limits, and they are very similar in many areas. However there are cases where the military application is unique and the characteristics of the emitters are different. Another thing is, in civilian use a certain amount of interference can usually be tolerated. In the military sphere more assurance is needed that nothing will happen. It gets to the point where somebody says, "Why do it?" [Unintelligible phrase]

Nebeker:

Has the exchange between the military and civilian communities in this area been friendly over the years?

Showers:

Yes.

Nebeker:

Have the people in the civilian side been frustrated by secrecy on the side of the military?

Showers:

No. The military wrote the standard 461, a military standard. Explanations of why things are done in this manner are in the appendix of the standard, the annex. That does not mean it is not debatable, but they have tried to [unintelligible word(s)].

Nebeker:

I suppose this question would apply either to the military or the civilian. Have these standards worked in the sense that it is then possible when equipment is contracted to specify allowable limits of interference of various sorts? Can one expect to get equipment without these problems at fulfillment of such a contract?

Showers:

There is never absolute certainty.

Nebeker:

How much after-the-fact removal of problems is necessary, and then how much can be eliminated through planning from the beginning of a project?

Showers:

If you want a number, I would say 75-percent of problems could be eliminated beforehand. But there are new devices coming on, their characteristics are not known and then there can be problems that were not even suspected.

Evolution of frequency measuring techniques and analysis

Nebeker:

Since we are on the big questions now, if you will indulge me I will ask another. Looking at the past fifty-plus years that you have been in this field, has there been a steady growth of more electronics straddled by more electromagnetic compatibility problems?

Showers:

It does not show any sign of slowing down. The techniques used in analysis are getting more sophisticated. Of course with computational techniques and digital instrumentation a lot of data can be taken – more data than can one even knows how to analyze. It amazes me to watch how the field just keeps going.

Nebeker:

Keeps going in the sense that there is always a need for new analysis?

Showers:

Exchanging information.

Nebeker:

What about the basic measurement techniques? Is there always a need to come up with new techniques?

Showers:

I think the only change in measurement techniques is extension in frequency.

Nebeker:

Is that right?

Showers:

There is some work going on in Boulder I think, NIST, linking broadband measurements [unintelligible phrase]. Over a broad band waveforms are measured instead of making frequency measurements. Then analysis on the waveforms is used to determine frequency characteristics.

Nebeker:

This is instead of initially measuring by frequency?

Showers:

That's right. [Unintelligible phrase] I do not think that has yet been proven as a viable technique, but it requires very sophisticated equipment to make those measurements.

Shifts in research funding

Nebeker:

Taking a big view of the field, have there been any historical events that have given a boost to or retarded the field or that meant that more or less research money was available?

Showers:

I have the feeling that the funds available to support military developments have decreased. Now, with the establishment of the European Union there is a lot of new activity in Europe.

Nebeker:

There is more research money in the European community recently?

Showers:

Yes. You say research money. I do not know from where the research money comes, but there has been a lot of interest in it. For example when we go to these meetings and recently there was a meeting in Korea. Representatives from Europe were there in full force, but we had trouble getting people from the United States to attend.

Nebeker:

There is a lot of interest in Europe.

Showers:

Yes. I think that there is more [unintelligible word(s)] dedicated to this problem in Europe, especially since they have the regulations in Europe.

Nebeker:

Are the EU requirements for the entire European community?

Showers:

Yes. They have adopted many civilian standards as requirements.

Nebeker:

Is there maybe more concern for these standards on the part of manufacturers in that economic sphere than elsewhere?

Showers:

It certainly has an impact there. In the United States the Federal Communications Commission (FCC) write the regulations, and they are working in the same fields and issuing requirements. I don't know. I think there is a problem in the way the Europeans do this kind of business as compared to the way the United States does it. The Europeans are more inclined to regulate.

Nebeker:

As opposed to waiting and seeing what actual problems arise?

Showers:

Yes, I think so.

Nebeker:

The FCC might wait until there are many complaints in some area before issuing a regulation?

Showers:

I don't want to speak for the FCC. There is a commonality there, but in general we in the United States wonder why some of the standards in Europe are written. They are more concerned about power planning in the power system. As I understand stand it, the utilities in Europe are required to meet certain standards for quality, but I do not know just what quality standards. There is an EN, European norm, which describes certain characteristics of the system. I do not think we have anything like that in the United States. We just have blackouts.

Nebeker:

Presumably this puts a burden on all the electricity producers in Europe having to meet high standards for their systems.

Showers:

Yes, that's right. They tend to regulate industrial equipment for example, whereas this is not really the case in the United States. Don't misunderstand me. There are certain requirements in the United States, but not as many.

Developing standards for information technology equipment

Nebeker:

What about new technologies? When for instance personal computers started coming into most offices and homes, did that give rise to a lot of problems that had not been before encountered?

Showers:

We had to write a new standard. They did the same thing in Europe. They wrote a standard for information technology equipment.

Nebeker:

What about cell phones? When cell phones became common did that require new standards and regulations?

Showers:

Yes. I do not know how serious the problem with cell phones is in the United States. I have one in my pocket. Does it interfere with anything when I turn it on? Will it interfere with my computer? I have never had any problems, but I have heard all kinds of stories about cell phones causing trouble.

Nebeker:

I am thinking that certain new technologies like the cell phone could be a real boost to the EMC community because there are a whole lot of new issues that require research.

Showers:

Sure. One of the concerns is the effect on a person's head.

Compatibility problems research; the effect of higher frequencies on research

Nebeker:

Yes. What has been the direction of your research? Have you gone to higher frequencies? Have you been concerned with a particular of compatibility?

Showers:

It has not changed much. I am not doing any research right at the moment. I am mostly doing international standardization and I belong to certain committees in the field. I do not quite know how to answer your question. My research has not changed a great deal in the last few years. I have stopped doing active research.

Nebeker:

I meant to ask about changes from the fifties and sixties until present day.

Showers:

It was higher frequencies mostly.

Nebeker:

The measurement techniques were higher frequencies?

Showers:

Yes.

Nebeker:

Have your concerns been regarding general measurement issues more than particular compatibility problems?

Showers:

More recently I have been interested in the low-frequency problems, the harmonic issues. That's because of the interaction in the work I am doing internationally. In U.S. field it is not a serious problem.

Nebeker:

Is this a compatibility problem through conductors?

Showers:

Yes, that's right.

Nebeker:

The electrical network.

Showers:

Yes.

Nebeker:

That is very interesting that the European community has been much more concerned with regulations than the United States.

Showers:

Yes. I don't know how much of this you want to publish, but when TC-77 first started it was primarily organized by the utilities to deal with this problem. The utilities in Europe succeeded in passing some requirements limiting harmonics.

Nebeker:

What were the problems that made them think about this at all? Was it a hum in audio equipment?

Showers:

No. Initially there was a problem with overheating. The harmonic currents overheated the neutral wire in certain locations. It was not really a compatibility problem in a sense. In the United States the problem was solved by increasing the size of the neutral conductor. As it turns out, the harmonic currents cancel in certain configurations in some conductors. That was a fairly common problem found in the United States when a lot of computers were put in the system. There was overheating in the wires. [Unintelligible phrase] I understand that has been solved. That is what industry people tell me. That may have started it. The other problem is that these harmonic currents distort waveforms. In Europe they had some systems, I guess carrier current systems, that depended critically on the voltage wave shape and sound waves [correct 2 words?].

Nebeker:

Are they using the power lines for carrier systems?

Showers:

Yes. They are sending signals out on power lines to control systems. I think that is done more commonly in Europe than in the United States. However when I say "commonly," it is not all that common in Europe. There are certain countries that use it and other countries that do not. With these regulations they are protecting those countries that need the protection. They say, "Okay, we've got to have minimum distortion in the system." That is one factor. But there are all sorts of arguments. For example one argument is that harmonic currents flowing in the power line dissipate energy due to the resistance in the line.

Nebeker:

Yes.

Showers:

That costs the power distributor money because that loss does not get metered.

Nebeker:

Presumably that dissipates or is lost more rapidly than the primary [unintelligible word]?

Showers:

Well, it is a loss. There is no question but that it is a loss. The issue is, who pays for that loss? The utility ends up paying for it. Therefore the customer is told, "You have to keep my waveforms clear." [correct 2 words?] If the customer has to keep it clear it is going to cost the customer. The point is, whatever the utilities cost, it is still the guy here that pays for it. The real objective is a minimal cost system.

Nebeker:

Overall minimal cost. Yes.

Showers:

We have not yet gotten a good model system to make that calculation. If you talk to the utilities or to the manufacturer, they say it's significant. We have seen figures of $50 billion per year cost worldwide to correct the problem.

Nebeker:

There would have to be a lot of energy wasted to compensate for that.

Showers:

Yes.

IRE and IEEE

Nebeker:

There are some other aspects of your career I wanted to ask about. We have talked a little bit about your involvement with IRE and then with the IEEE after 1963. You have been involved with standards committees especially. It take it that you feel that the IEEE is doing very important work with standards.

Showers:

Oh yes.

Nebeker:

How has that been over the years? Have things functioned the way they should?

Showers:

Yes, I think so. The relations have been good. We have worked with the Federal Communications Commission and they have adopted our standards from time to time – not all of them, but some of the major ones. They are written into the rules. I think it has worked pretty well and been effective.

Nebeker:

Were you pleased when the IRE and AIEE merged in 1963?

Showers:

It seemed more like the IRE was taken over by the AIEE than vice versa.

Nebeker:

I know you were an IRE member. Were you an AIEE member?

Showers:

I think I was an AIEE member.

Nebeker:

You were a member of both organizations.

Showers:

Yes. There was a hiatus for a couple of years. I don't know what happened, but basically I was a member both of those organizations. I was more active with my committee work and so forth in IRE.

Nebeker:

Some IRE people told me they had not been in favor of the merger. Harold Wheeler was one.

Showers:

Yes.

Nebeker:

It was felt that they were different organizations and IRE had its own character and should stay separate. Would you agree with that assessment?

Showers:

Are you asking whether I think they would be better off if they had not merged?

Nebeker:

Mostly it is a question of what you felt at the time. Historically it is interesting to know what engineers felt at the time that merger came about.

Showers:

IRE seemed to be a more informal organization, not as highly structured. I don't remember the size of it.

Nebeker:

IRE grew rapidly after World War II. I believe it had gotten to just about to the same size as the AIEE.

Showers:

I thought the reason they merged was that industry felt they could not support both organizations. I do not know whether IEEE was financially embarrassed. I simply became convinced that the merger was inevitable. And I think I would have been able to see [unintelligible phrase].

Nebeker:

Do you remember any problems in the professional group on electromagnetic compatibility as it made the transition?

Showers:

No, not really.

Nebeker:

How has that society functioned over the years from your viewpoint?

Showers:

I should say I have been satisfied with it. I could raise questions about paper reviews and that kind of thing, but that does not have anything to do with the merger.

Nebeker:

I am now asking quite generally about your opinions about how EMC society has functioned over the years.

Showers:

I really do think it has done well. The nature of it has been in good shape.

Nebeker:

Have its publications and annual meetings and so on done the job they are supposed to do?

Showers:

Yes, in general, I think so. Yes.

Nebeker:

Have you ever felt like quitting?

Showers:

No. Well, I did drop out of management.

Nebeker:

You had many jobs.

Showers:

I had enough to do.

Working with graduate students; retirement at U. of Penn.

Nebeker:

Right. I also wanted to ask about your work at Penn. You have supervised a lot of master's and doctoral theses. Have you been very glad to do that work?

Showers:

Yes. I never had enough time to do it, but it certainly [unintelligible word]. I spent at least half my time working on research contracts. [Unintelligible phrase]

Nebeker:

I have not had time to look at the list the research graduate students you had. Has that been fairly steady over the years?

Showers:

Well, I am not doing any right now.

Nebeker:

But until recently.

Showers:

Yes. Until I retired I guess it was pretty steady, but I had fewer and fewer towards the end.

Nebeker:

When did you retire?

Showers:

About 1989.

Nebeker:

You were named emeritus professor in 1989. You started here in the late forties, but from the fifties onward you had graduate students?

Showers:

Yes.

Nebeker:

Has that been important to you in your research, working with students?

Showers:

Oh yes. I think it has actually been very productive.

Nebeker:

Are there one or two of these graduate students that stand out in your mind?

Showers:

I will have to think. The trouble is that I have lost contact with almost all of them. Wolfgang Burner [spelling?] was at Chicago I think? About three years ago he got a very significant award. It was a recognition from a European university. I will have to go down the names. One fellow went out to Boeing [correct word?]. He was very good.

Nebeker:

Were most of these graduate students also in electromagnetic compatibility?

Showers:

Yes, almost all of them.

Nebeker:

Were they in general successful in finding jobs in that field?

Showers:

I have not followed them. But yes, I would say that at the time they had no trouble getting jobs. What has happened after they got new jobs [unintelligible phrase; I no longer had contact with them].

Nebeker:

I am sure you would have heard about it if they people were not able to find initial jobs.

Showers:

Yes. It is strange contact is lost with most people.

Nebeker:

You stopped teaching in 1989. Did you continue doing research in the nineties?

Showers:

Yes, for a while.

Nebeker:

And you are now very much involved now with committees.

Showers:

Yes. My activities are practically all professional [unintelligible phrase]. I am involved with the U.S. committee C-63 [unintelligible word(s)] EMC [unintelligible phrase]. I am also technical advisor for parts of the activities in the CISPR and T-77 [unintelligible word(s)]. I just came back from Korea. We had a large joint meeting of committees. That keeps me busy.

Nebeker:

It sounds like it. You have received a lot of awards, including the Lord Kelvin Award. That is quite a distinction. Is there anything I have not asked about on which you would like to comment?

Showers:

I can't think of anything.

Nebeker:

You will have an opportunity later if you want to make any additions.

Showers:

Let me think about it a while and see if I can add some things.

Nebeker:

Okay. Thank you very much.

Further Materials

Interviews with EMC Founders Milton Kant, Mervin First, and Dr. Ralph Showers