Interview with Grote Reber on 25 October 1975

Title

Interview with Grote Reber on 25 October 1975

Description

Grote Reber, 1911-2002. Interviewed 25 October 1975 at the University of Washington, length of interview: 195 minutes.

Creator

Papers of Woodruff T. Sullivan III

Rights

NRAO/AUI/NSF

Type

Oral history interview

Interviewer

Sullivan, Woodruff T., III

Interviewee

Reber, Grote

Location

Seattle, WA

Original Format

Audio cassette tape

Duration

195 minutes

Interview Date

1975-10-25

Interview Topics

Family and educational background in Illinois, engineering jobs in Chicago, relationship to Jansky and his work, building of his dish, many details on receivers, dish, observing; publishing in ApJ, relationship to University of Chicago and Yerkes Observatoy astronomers, influence of Compton, style of operation, solar work at NBS, sea-cliff interferometer on Haleakala, low frequency work in Tasmania.

Notes

The interview listed below was either transcribed as part of Sullivan's research for his book, Cosmic Noise: A History of Early Radio Astronomy (Cambridge University Press, 2009) or was transcribed in the NRAO Archives by Sierra Smith in 2012-2013. The transcription may have been read and edited for clarity by Sullivan, and may have also been read and edited by the interviewee. Any notes added in the reading/editing process by Sullivan, the interviewee, or others who read the transcript have been included in brackets. If the interview was transcribed for Sullivan, the original typescript of the interview is available in the NRAO Archives. Sullivan's notes about each interview are available on the individual interviewee's Web page. During processing, full names of institutions and people were added in brackets and if especially long the interview was split into parts reflecting the sides of the original audio cassette tapes. We are grateful for the 2011 Herbert C. Pollock Award from Dudley Observatory which funded digitization of the original cassette tapes, and for a 2012 grant from American Institute of Physics, Center for the History of Physics, which funded the work of posting these interviews to the Web.

Please bear in mind that: 1) This material is a transcript of the spoken word rather than a literary product; 2) An interview must be read with the awareness that different people's memories about an event will often differ, and that memories can change with time for many reasons including subsequent experiences, interactions with others, and one's feelings about an event.

Series

Working Files Series

Unit

Individuals Unit

Transcription

Transcribed for Sullivan by Bonnie Jacobs.

Sullivan

This is talking with Grote Reber at the University of Washington on 25 October ’75. Now, I was asking you about the article you sent to Astrophysical Journal in 1940 and what was the reception that you got?

Reber

The reception was one of doubt. I was invited to come up there [Sullivan: to Yerkes Observatory] and give them a colloquium on the subject, which I did. As a matter of fact, I'd been up there a number of times beforehand because before undertaking the experiments I canvassed around to see what else was being done. And I'd been told by Jansky that they [Sullivan: Bell Labs] weren't going to do anything more. I'd contacted Shapley at Harvard. They were very aware of Jansky's work, but they weren't going to do anything. I talked to Struve at least once and perhaps several times with the idea of seeing if he could help raise some money to do these things and if they were going to do anything. And he said in effect that they weren't going to do anything and the reason they weren't was that they had their hands full with their own business and that they deemed this to be outside their sphere of competence. And as far as raising money was concerned, he didn't have enough money for his own purposes. In other words, they were aware of it but they weren't going to do anything. So here was a situation where a scientific opportunity was open and nobody was going to do anything.

Sullivan

What is your opinion as to, was it just a matter they felt that it wasn't that important and besides they didn't know anything about it? Is it fair to say they were shortsighted?

Reber

No, I wouldn't say they were short-sighted. You have to remember, in that day even the photoelectric cell and a D.C. amplifier were a mysterious black box. When it came to vacuum tubes and amplifiers, tube circuits, and all the rest of it, they just didn't have any comprehension of these matters. And they didn't build radio sets, they weren't even radio amateurs. If they needed a radio, they went out to a store and bought one. And consequently, from their point of view it would be foolish to embark on anything like this. The chances of them going wrong would be about a hundred to one.

Sullivan

But might they not have hired a couple of radio engineers if they thought that the astronomical results would be exciting enough, interesting enough...

Reber

I don't know what their thoughts on that were. The thing that dismayed them was the lack of resolution. The only data available was Jansky's that had a resolution of about 30°. In other words, you could tell the difference between the Milky Way and not the Milky Way and that was about all. Well, in their eyes anything as crude as that didn't have much astronomical merit.

Sullivan

Right, how were they ever going to tie it in with their optical work?

Reber

And they had no way of knowing how it could be improved. They weren't antenna engineers. And they were going to get in way over their ears if they weren't careful. I think this is characteristic of all the optical people. This branch of physics relating to electromagnetic waves, at least of this nature, just wasn't part of their repertoire and that's the reason Harvard didn't do anything and the others didn't do anything.

Sullivan

So did you contact anyone else besides Shapley and Struve to try to convince them, any other astronomers?

Reber

Well, I can't remember at this late date, but I do remember those two because Harvard was considered one of the leading observatories and Yerkes was close by. And I knew the people at Yerkes.

Sullivan

You probably were aware of the Whipple and Greenstein paper in 1937...?

Reber

Yes, I was aware of that.

Sullivan

So to a small extent Harvard did try to do it, theoretically anyway.

Reber

Yes. I've forgotten the details of that paper, but if I remember all it did was prove that the phenomena they proposed wouldn't work.

Sullivan

Right. Dust grains, mainly.

Reber

What was the phenomenon that they proposed?

Sullivan

Just thermal radiation of dust and they showed that the dust could not be any more than a few degrees.

Reber

That’s right, I remember.

Sullivan

And yet the other [Sullivan: radio emission] was millions of degrees.

Reber

It wouldn't possibly work. And then I came forward with free-free transitions.

Sullivan

Right. Ok, there are so many things to ask you. How did you come up with the free-free idea? Where did that come from?

Reber

Really at this date I don't know. But free-free transitions were part of a course I took at the University of Chicago. I took some astronomy courses there and mathematics, and physics, and a variety of things. And in some manner free-free transitions were brought up to demonstrate some optical phenomena. I don't recall what that optical phenomenon was, maybe it had to do with corona of the Sun, I don't know. Anyhow, it came up and it was demonstrated that this phenomena, whatever it was could be explained in terms of free-free transitions, some high kinetic energies. And I thought to myself, you know this might be worthwhile investigating. So I took these same formulas and put in lower frequencies and some suitable temperatures and lo and behold it looked as though the numbers came out, might be vaguely within an order of magnitude fit Jansky's results, while Whipple and Greenstein didn't come within several orders of magnitude.

Sullivan

Do you remember which course this was, as to who taught it and so forth?

Reber

I think it was one I took with P.C. Keenan.

Sullivan

With him?

Reber

He was the instructor. I took quite a few courses there, I've forgotten the details of them.

Sullivan

As a graduate student more or less?

Reber

Yes. I had courses in infinite series and a whole lot of that kind of stuff, and geometric optics. It probably wouldn't be in any of those, probably in Keenan's course.

Sullivan

Do you know the topic of the course?

Reber

I don't know, but probably some kind of astrophysics.

Sullivan

Maybe stellar atmospheres?

Reber

Could be. Anyhow, it was in this course in astrophysics that this business of free-free transitions was brought forward to explain some optical phenomena. I thought to myself now here's a new scheme, this might be worth investigating from a Hertzian wave point of view. I put in some numbers and it looked pretty good. And that's that.

Sullivan

Right, so you published it first in the Proceedings of the IRE [Institute of Radio Engineers]?

Reber

That's right.

Sullivan

But now what was your motivation to try and put it into ApJ [Astrophysical Journal]?

Reber

That was a pretty crude dissertation- see this is all pretty far back- but I think the reason it went to the Institution of Radio Engineers was that the original paper that finally appeared in Astrophysical Journal a few months later, if you recall, mainly related to the results, you see. And Struve stuck to his guns that they were astronomers and not engineers and that he felt that anything that appeared in the Astrophysical Journal should be primarily related to astrophysics and not engineering. And I think what happened was, at this late date, that the part that I wanted to put in related to the equipment was edited out by Struve and so I sent it to the Institution of Radio Engineers. That's as clear as I can remember.

Sullivan

It seems to me that the ApJ paper is almost exactly the same as the IRE paper except for the elimination of the whole free-free interpretation.

Reber

Yes.

Sullivan

Which then is in Henyey and Keenan's paper afterwards. Not even the 1940 IRE paper has much on the equipment, the 1940. The 1942 one goes into a lot of detail.

Reber

That's right.

Sullivan

But are you saying that your original manuscript for the ApJ did have much more on equipment?

Reber

I think it did. I think it had pictures of that early equipment. If you remember some appeared and some data, that I'm pretty sure was all sent to Struve.

Sullivan

I see. And what about your theoretical work? So he wanted to cut out the description of the engineering side, but how did it work as far as the theory goes? What was his reaction about all this?

Reber

The reaction seemed to be that, at least as far as people at Yerkes were concerned, there was a wide spectrum. Keenan had an open mind, and he'd been the first one to come down and take a look and satisfy himself that it wasn't an out-and-out hoax. Attitudes ranged through doubt to innocuous disbelief to Kuiper who was at the other end of the scale and I remember distinctly him telling me that he thought I was crudely in error, that all I was getting was noises out of arc-lights. In other words, he was an absolute doubter. But he hadn't been there yet to see this stuff. And I don't think he was very cognizant, oh, he must have read or at least known about it but I don't think he'd taken the bother to read in any intelligent manner of Jansky's results. Struve had, I'm pretty sure. And people like Chandrasekhar sort of stood by the sidelines and looked to see what went on.

Sullivan

Watched the whole show and side with the victor after it was all over.

Reber

So it wasn't a situation where there was a tight group that had any particular ideas on this matter. There was a spectrum of opinion.

Sullivan

And did you discuss these results before you sent the paper off or before your colloquium? Or was it that all of a sudden this all came upon them...?

Reber

No. I must have discussed it individually with several of these people beforehand. Otherwise they wouldn't have given me the invitation to come and give them a talk.

Sullivan

And you gave the colloquium just before you submitted the paper more or less?

Reber

Oh, a year or so.

Sullivan

So it was more preliminary, I guess?

Reber

Yes, it was certainly within a few months of the time got some initial results. I think I got those initial results in the spring of '38, wasn't it?

Sullivan

Or '39, it says in your paper anyway.

Reber

Something like that. Well, it was within a few months of that. [Sullivan: was October 1939]

Sullivan

What was the reaction at the colloquium itself? Did you feel like you were in a den of lions?

Reber

I can't remember. There were quite a number of graduate students there, including this Olin Eggen, who is now in charge of Mount Stromlo, and he remembers that colloquium very well. In fact, listening to him he remembers it better than I do [Reber: So does John O’Keffe]. There were quite a few people there, maybe 30, maybe more, because most all the staff was there and a considerable number of graduate students. This was at Yerkes. I don't remember that there was anybody from the University [Sullivan: of Chicago] that came. There were quite a number of questions, but in retrospect I don't remember that they could be called intelligent questions. I think the background of the audience, that is the students and the professors, wasn't suitable. They didn't know enough to ask intelligent questions. And consequently there wasn't a great discussion about...

Sullivan

But they weren't...

Reber

They weren't against it.

Sullivan

I mean they weren't trying to knock you down either.

Reber

No.

Sullivan

It was just sort of outside, like you say, their sphere of knowledge.

Reber

Yes.

Sullivan

But now is it true that after you submitted this paper to Struve that he specifically at that time sent someone down to check you out, so to speak? This is the apocryphal story. I want to find out if it's apocryphal or true, I guess.

Reber

Struve himself didn't come. Keenan was down at least once on his own. Then he [Reber: Struve] came and I remember that Kuiper came with Keenan. Kuiper's attitude was very different at this time. It must have been within a year that he changed his mind. There were some others with him, who I don't remember. There may have been, now that I think about it, there probably were a couple of graduate students who came along. It was a party of half a dozen. I remember Keenan and Kuiper. Whether Chandrasekhar ever came or not, I don't know, I can't remember, he may have.

Sullivan

And did you have a definite impression that this was a proving for you, that whether or not your paper got published would depend on...?

Reber

No, I don't think so. I think that was determined before that. You ask me questions about which I really don't have any great knowledge. I wasn't a member of the staff at Yerkes or on the Editorial Board or anything. But the impression I got was that the Astrophysical Journal as of that day was pretty much solely edited by Otto Struve. And what he decided went in and what he decided went out. It wasn't by any referee system or anything like that. This is just my impression. So after Keenan had been there and we discussed these things, then a second delegation came, half a dozen, as I say. And I think there were some other visits. Oh, I know there were, not immediately, but in succeeding years. Oh, I got quite a few delegations that would come.

Sullivan

Well, Jesse Greenstein told me he came.

Reber

Oh yes, say, he maybe was on that second group, probably now that you mention it because I know he was there, just when I don't remember any more.

Sullivan

And what did you do on these visits? Did you move the dish around for them and show them how the signal varied, etc.?

Reber

I showed them some of the results. And, of course, they always came in the daytime when the automobile ignition was very severe, so you couldn't show them anything very interesting as far as results were concerned, being taken. Whether or not that particular group or a succeeding group, I don’t know. There were some groups or some individuals, who I urged to come an hour before noon and watch the equipment as the Sun transited. And this was quite impressive.

Sullivan

This was after you detected the Sun, of course?

Reber

Oh, yes, 1943. Because that's about all you could show them in the daytime. And then still later, about 1945 when solar activity rose, there wasn't anybody from the Observatory, but there was somebody else, in fact, three other people. One of them was Ken Norton of the Bureau of Standards. They showed up by pre-arrangement on a particular day, early, maybe 10:30 in the morning because I wanted to show them what happened when the Sun went by. This is at 480 megacycles by this time. It must have been 1946. And it dumbfounded me too, but what happened was that the Sun was very active that day, far beyond anything I had ever encountered, and way before the Sun was supposed to transit there were a lot of small blips on the record. And you could listen, swssshwhishing noises, and they disappeared after about maybe five minutes. And then they came in again only stronger and they rose and fell, rose and fell. And then they disappeared. The second time some of them went nearly to the top of the scale. And the third time when the Sun should transit there were a few of these blips then the pen rapped right up hard against the pin and stayed up there for about 15 minutes. And then it came down again. And then it went through this same cycle in reverse.

Sullivan

So these were sidelobes...

Reber

Sidelobes.

Sullivan

I mean did you know you had all these sidelobes out there?

Reber

No, You wouldn't find the sidelobes in normal conditions but these things were about 40 dB or 50 dB up. And I remember these fellows saying, "Look, the thing's off scale," and I said, "Yeah, it's off scale," and he said, "Well, turn the gain down," and I said, "You can't turn the gain down that much, it will only turn down maybe eight or ten dB, that's not near enough." "Oh," they said, "there must be some way of turning the gain down." I remember somebody said, "How do you know it's coming from the Sun, this is maybe something else?" So we went out and we unloosened the machine and turned it away from the Sun and it all went away. So we turned it back to the Sun and it all came back. And that really convinced them.

Sullivan

No doubt about it.

Reber

It was tremendous. It was nothing like anything I'd ever seen.

Sullivan

Just to go back to one more question about the 1940 paper. Was it a matter that Struve said to you, "Well, here's how much of your paper we publish," and you were happy just to get that published?

Reber

Yes, I think that's what it arrived to.

Sullivan

And did you know that Henyey and Keenan were going to essentially- I mean they gave you credit for the idea, but then they went ahead and worked it out in much more detail.

Reber

Yeah, as a matter of fact, I think, vaguely now, Struve didn't issue an ultimatum, but he stated that these astronomical matters should be dealt with by astronomers. And he sort of instructed Keenan that he needed to work this thing up and to write up a paper which would be a supplement to mine. I think it was fair.

Sullivan

Yes, it's a good compromise. That's what Keenan told me, yeah. That was his impression; once again he wasn't exactly sure.

Reber

In other words, they were to work it up properly.

Sullivan

Ok, if we can I'd like to go back now to right back to the beginning, so to speak. And ask you a little bit about your background, if you don't mind, about where you grew up and so forth.

Reber

I grew up in childhood in Wheaton, Illinois.

Sullivan

I see, that your home town actually.

Reber

Oh yes. I was born in Chicago but as soon as I was a few days old they took me out there to the maternal home. There's an interesting thing in relation to that. Most babies make their presence known long before they are born, and so there is a lot of discussion about what the newcomer is going to be, and there's a whole variety of names associated with the newcomer, to be slapped on him as soon as he arrives. Well, my parents were sort of delinquent in that matter. I guess I was the chief feature of the action, but in any case I don't remember these things at that stage. However, my birth certificate testifies simply that a male child had been born to so and so, and so and so, one "Baby Reber." That’s all it said. Apparently they had to issue this birth certificate within 48 hours or something, and by that time they hadn't been able to make up their minds. So that's on the birth certificate.

Sullivan

What is the name Grote, by the way? It's not a common name.

Reber

Well, a custom of a lot of central European people to give the child the mother's maiden name as a middle name. And then to give him some ordinary handle for the first name. So I should have gotten a name like Henry or William or Frederick, or something like that, then be say, William Grote Reber. They didn't do that. My mother was Harriet Grote, so they called me Grote Reber.

Sullivan

Your mother's maiden name, I see.

Reber

Well, this has been sort of a nuisance throughout life because I should be called Bill or Hank or something.

Sullivan

Oh, I don't know, you get tired of those names.

Reber

Anyhow, they were delinquent in that and in that day it didn't make much difference because birth certificates were just pieces of paper that nobody paid much attention and to. But as time went on, we got more regimented and birth certificates became more important. Very fortunately about 1940 before my mother died, my father died rather earlier, I had her write a document signed by a Notary Public testifying that this "Baby Reber" on the birth certificate was in fact the same individual that was Grote Reber. This has been of considerable assistance because if I had a birth certificate, that all it's got on it is "Baby Reber." Anyhow, those two are stapled together now.

Sullivan

So, was all your primary and secondary schooling in Wheaton also?

Reber

Oh, yes. Matter of fact, the primary school was less than two blocks of where we lived. Secondary schooling was 3/4 of a mile away.

Sullivan

And when did you first start getting involved in radio?

Reber

Oh, when I was in high school, I was one of these radio amateur fellows.

Sullivan

This is about what time now?

Reber

We lived in a fairly free and easy manner, but far from opulence. This was sort of an open place and there was a good garage out in back and there was a large yard. We had half an acre to fool around in. We had trees, my parents did some gardening, and we had a few animals like cats and dogs, things like that. And there were some rather large trees around we'd climb and they were super for hanging aerial wires on, that kind of thing.

Sullivan

What time is this now, what year roughly?

Reber

Well, I maybe was a junior in high school by the time I got my first radio amateur license.

Sullivan

But what year would that be?

Reber

Oh boy, 1928, maybe. That’d be about right- I was born in 1911, 1928 I'd be about 17, that would be about a junior in high school.

Sullivan

And may I ask what profession your father was?

Reber

Yes, he was a canned-good manufacturer. He was a senior partner in a firm of Reber Preserving Company. It was just a small operation. They sold most of their products in Chicago. The factory was in a place called Eola, E-O-L-A, about maybe 15 miles from Wheaton. He inherited it from my grandfather. I had an aunt once [Reber: Myrtle], a sort of social climber and she thought it would probably enhance her social position if she could become a member of the D.A.R. [Daughters of the American Revolution] and so she hired one of these chronology people to search out her ancestry. And I'm pretty sure this is right, but anyhow, it was through her that it was found out that part of the Rebers that we descended from were a couple of Reber brothers who came into Pennsylvania from near Strasbourg in, I think, 1708. And they were just farmers and lived in Pennsylvania, I think, in Bucks County or somewhere. Anyhow, then during the Civil War my grandfather fought on the side of the North, but he wasn't exactly a military man and so he got himself captured and in that day they exchanged prisoners. The theory was that if you were exchanged you couldn't do anymore fighting, you could only support them in some non-military capacity. So effectively after he got himself traded off, then he was out of the War, all of this was related to me in very much later years. Anyhow, he decided he wanted to go where he thought there was more opportunity. I don't know what his background was, I guess nothing in particular. At least I was never told that he had any training in anything. And he came out to Chicago and he set up on his own manufacturing preserves, jams and jellies, that kind of thing. He prospered because he was a very industrious individual. They had the Reber Preserving Works and he had several sons and he named them, I guess customary in those days, after people he thought were important. One of them who died before my time was an Irving Reber, apparently named after Washington Irving. Although I gather my uncle, whom I never knew, had no literary capability whatsoever.

Sullivan

It was an attempt anyway.

Reber

Yes, from the canners at the preserve works. Then I had another uncle who died not so long ago who was named after the inventor of the steam engine, James Watt [Reber: he had no mechanical ability whatsoever].

Sullivan

James Watt Reber. And what was your father's name?

Reber

He was named after a Pennsylvania politician, whom my grandfather thought was quite a fellow, named Schuyler Colfax. I gather from more recent comments that he was a somewhat dubious politician [Reber: My father had no political ambitions]. In any case, that's the way it was.

Sullivan

But now you did not inherit the canning works, I presume? You decided you wanted to do something else?

Reber

Well, it was still going some years ago, but I had no interest in that. And it gradually passed into hands of one of my cousins and the last that I know he was running it.

Sullivan

What did you do after high school?

Reber

It was by that time very evident that I wanted to do something in engineering. And I was sort of inclined electrically, so my parents had the wisdom and foresight to send me to the Engineering School in Chicago called the Armour Institute of Technology. It later amalgamated with something else and became what's now the Illinois Institute of Technology and that "A" is this A for Armour. It was a school where they taught engineering, you know with calculus and all the rest of it. And they had a dynamo lab and chemistry lab, and this kind of thing. And we got a pretty good inculcation in the actual doings of engineering. But they leaned over heavily on things which I think are skipped today pretty much in that we had a lot of stuff which would be called trades.

Sullivan

Machine shops and...?

Reber

Oh yes, foundry machine shop, pattern making, forging, a lot of that stuff. In fact the first two years were heavily given to this trade stuff. I think in later years the more intellectual ends of the school got control of it and pitched most of that out. But it served me in good stead because now I can go out into shops and talk to these guys and not be given a lot of guff.

Sullivan

So you went to this school for four years?

Reber

Four years, graduated with a Bachelor of Electrical Engineering.

Sullivan

And what year?

Reber

1933.

Sullivan

And then what was your next step?

Reber

That was in the Depression and so I worked around at odd jobs of one kind or another. Finally I got work in the radio industry in Chicago. It must have been about a year later.

Sullivan

Which company?

Reber

I worked for three radio companies at different times until 1947.

Sullivan

Can you tell me which companies?

Reber

Yes, I worked for Belmont Radio Corporation, Stewart Warner Corporation and General Household Utilities. I think they've all disappeared now, either by going bankrupt or by amalgamation.

Sullivan

And what sort of work did you do for these?

Reber

I did various things. First I worked in a test equipment department, making and constructing test equipment for testing their products. I didn't actually test the receivers, but I helped build and install the equipment used for testing receivers. The actual testing of the receivers was considered a laboring job.

Sullivan

These receivers were home radio sets?

Reber

And automobile radio sets, that's about the only kind of sets they manufactured at that time, auto radio and home radio. Then apparently I had a certain amount of ability and I got moved up into the Engineering Department, first as what they called "solder-slinger," that is, you know, putting all these samples together. And then later manipulating the test gear and designing the radio sets. And I worked in that capacity until 1947.

Sullivan

So towards the end, those last years you were actually designing radio circuits and so forth?

Reber

Yes.

Sullivan

For a wide variety of applications.

Reber

In there, of course, were the War years and in that case we didn't design anything, but we took the samples- these military agencies would come forward with radar, IFF or direction-finding gear or something that they'd built in the government laboratories and then they'd want us to manufacture them.

Sullivan

What does IFF stand for?

Reber

Identification: Friend or Foe.

Sullivan

I know what this is, right.

Reber

The scheme as that if you had aircraft out in the skies, you want to find out whether they're your aircraft or somebody else's aircraft, in other words to identify them. And so there was a thing on the ground called an "interrogator" and it sent out a pulse and then if it was your aircraft it would send back the proper code. And then you don’t shoot at it.

Sullivan

Right, these people manufactured these things?

Reber

That's right. So I assisted in the organization of these things and helped them get them made. That was during the War years. And then after the War we went back to making radio sets.

Sullivan

Ok, this is continuing with Grote Reber on 25 October ’75. I was asking you if you ever had any interest in astronomy.

Reber

Well, yes. I was always, I think, from a child interested in astronomy. I attempted I remember a number of times to talk to my parents, but they weren't interested in these things. They weren't any more interested in science or the world surrounding them than the people are today. Most people are pretty uninterested in the natural world that surrounds them. And I was given a camera at a rather early age, maybe 12 or so, and just recently within the past few weeks when I was digging through my archives I stumbled over some old photographs I'd taken at that stage. I don't know exactly when they were, but they must have been in the 1920s. I'd apparently set the camera on a fence post with the shutter open and took pictures of the stars and got streaks; some I've made notations on. I think there was a configuration of four planets out in the west. I took pictures of these... I remember now. These were developed and, of course, I'd expected to see the streaks of the bright planets. But I was dumbfounded to find streaks on there of stars which I couldn't even see. This I'm sure was before 1930.

Sullivan

This is during high school probably, or junior high school, maybe?

Reber

Because we moved ’32 [Reber: 1934], not far, just 50 yards or so, and pictures are taken from a place which must have been when I lived in the old home. So it would have been before 1930. You see I was fairly young at the time.

Sullivan

And did you study any astronomy at the Institute?

Reber

No. See astronomy was not the kind of thing you'd get in engineering school.

Sullivan

I thought there might have been an odd course, or something.

Reber

No, I read some astronomical books, you know, of my own volition at the local library. Incidentally, the small town of Wheaton, I don't know what the population was at that day, maybe 3,500, but it was very fortunate in having some wealthy people who were public spirited and one of them had given a very fine library to the community. I guess it's still there. And I got books from that, but that was all.

Sullivan

Ok, so you did have a peripheral interest in astronomy anyway. But I think you're sort of curious about everything that's going on around you.

Reber

Oh, that’s true.

Sullivan

Astronomy was one of them. And when did you first become aware of Jansky's work?

Reber

I think very soon, at the time those papers were published. I was a radio amateur and naturally interested in radio. I didn't have much of any money at that time, nobody did. So I didn't go off buying magazines. But the school that I was going to had these engineering magazines and I used to read them regularly because they had a lot of interesting articles about equipment. And this article by Jansky today probably wouldn't have been published in an engineering magazine. It probably would be some physics magazine or astronomy. Anyhow, it appeared in this engineering magazine and I was immediately greatly struck by it.

Sullivan

Even the first article?

Reber

Oh, yes. You see I was still in school and I didn't have any money or anything. Times were very different. The young people today have no comprehension of how things were then. Everyone today has lots of money in their pocket but nobody had any money in their pocket in that day. And it wasn't until I had gotten out of school and was able to make my own way that I had enough money to do anything with.

Sullivan

Are you implying that if you had some money at that time that you might have wanted to follow up Jansky's work right then?

Reber

Perhaps, perhaps. Although it's speculation.

Sullivan

It's hard to say, of course.

Reber

But in retrospect it's pretty easy to see. I got interested in actively doing something about 1936. Well, I got out of school in '33, there was at least a year or more before I got a job worth anything, so it was about 1935 by the time I got a job where I could support myself and have anything left over. So it was probably about the following year that I felt affluent enough to have any wherewithal to do anything.

Sullivan

And by this time Jansky had published two additional papers, of course.

Reber

That's right.

Sullivan

Which probably whetted your appetite even further.

Reber

Could well be. And I remember writing to Jansky. I think I can still produce a letter, asking him- you see by this time I was working in the radio industry in Chicago. I wrote to him asking him if they were going to do anything more on this. And if they were I would like to be considered as an applicant for such job as might be open. And he wrote back and said they weren't going to do anything more, and unfortunately that was that.

Sullivan

Now I have some questions here that I wanted to ask you about Jansky. You may not know them, but here is one of them: What do you know about why Bell Labs did not follow it up? Did Jansky really want to and his bosses wouldn't let him? Do you know anything about all this?

Reber

I wasn't there and there seems to be a difference of opinion. This man from New Hope, Pennsylvania wrote a book where he purported to go around and interview Jansky's relatives and read Jansky's letters.

Sullivan

Oh, you mean Pfeiffer?

Reber

I guess so.

Sullivan

John Pfeiffer?

Reber

Yes, I think that's the guy.

Sullivan

In the ‘50s he wrote that book, yes.

Reber

Anyhow, he attempts to develop a case that Jansky was suppressed. I have no information on that whatsoever. Then some years later, not too many years later, Friis writes himself some letters in Nature or Science, defending himself saying that he wasn't the guy that suppressed Jansky. Now I have no information whatsoever about any of that.

Sullivan

You don't. I thought you might have known Jansky well.

Reber

Oh, no. I met him two or three times, but that was all.

Sullivan

I see. Ok, I've got to do some more digging at Bell Labs to try and get this story straight.

Reber

I don't think you can. I'd say this, you see your memory gets fuzzy. Preparatory for this Jansky lecture [Sullivan: given at NRAO] I've been digging through my archive down there [Reber: Tasmania]. Burke and Franklin from the Carnegie discovered radio waves from Jupiter by accident in 1955 at a frequency of 22 megacycles. At that time I was in Tasmania making my first exploratory experiments. And I looked through my old Hawaii records and I was able to find some in 1952-1953 which I could attribute to Jupiter at about 20 megacycles. I didn't recognize them as such.

Sullivan

A similar effect, Shain did the same thing, of course.

Reber

Yes, even earlier about 1950-'51. So I thought to myself, "By golly I'll bet you Jansky's got a lot of that stuff [Sullivan: Jupiter]." He had over a year of continuous recordings. So I wrote to the Bell Labs at 453 West Street, saying just what I told you, that I would like to find out about the situation on Jansky's recordings, that I would be in the States the next year and I would like an opportunity to look these things over. I got a letter back rather promptly from somebody saying that they had Jansky's notebook and folded into the pages of the notebook was one of his recordings. But all the others had mysteriously disappeared. So I didn't follow it up. But then I found you see, your memory gets poor, that's why written pieces of paper are better than just memory. That's the reason I'm a bit dubious about you taping all these recordings.

Sullivan

No, I take that into account. I mean, before you really believe anything you have to have some more documentation for it. They're all such useful leads.

Reber

Anyhow, just within the past few weeks in digging through my archives I found a piece of paper in my handwriting and it's dated the 18th of February 1956. It says, "According to Southworth, Jansky's recordings were kept in an old farmhouse which was demolished in 1949, H. T. Friis in charge." That all it said. I don't remember this. Apparently it was a telephone conversation. And I have no record that I followed up with Friis or anybody else. But that little piece of paper is there, in my handwriting.

Sullivan

That may have been the fate of Jansky's recordings though.

Reber

So, so... Anyhow, that was 1956. Now, another thing happened entirely unconnected and unexpected. But in 1960 or ‘61, I was at Green Bank, West Virginia, supervising the reconstruction of my dish. And they were embarking on some microwave experiments because about that time the 85 foot dish was being completed, although it was quite a few years before the 140 foot dish got finished. And they had some pretty competent technicians there and a couple of good engineers. Anyhow, they invited down from Bell Labs a man named A. C. Beck, who was a contemporary of Jansky's, to look at what their microwave boys were doing because Beck apparently was an expert on this microwave relay stuff. And they wanted to get some independent opinion on the competence of what was going on at Green Bank. So Beck was there on that mission. He was there for two or three days. And so I had an opportunity to sit down a number of times and talk to Beck. Beck was a contemporary of Jansky's. He didn't participate with what Jansky was doing but he was there at the time doing other things and very aware of what Jansky was doing. If you recall the famous photograph of Jansky in knickers and his big machine, it shows that the antenna arms are pipes and that the machine is supported on wheels that have pneumatic tires. After Jansky's experiments were finished, Beck used that machine. The parts were taken off and it was used for setting up an antenna measuring experiment. That is, the transmitter was put off at some distance and the antenna under test was put on this machine and turned around and they got the pattern. And he was very positive that that machine had hard rubber tires, absolutely. So this merely tells you that somewhere in the interim the Service Department got tired of inflating the tires and put on hard rubber ones.

Sullivan

Because originally they were old Model A tires?

Reber

That's right. Model T's, I think.

Sullivan

Let me ask a more general question. Do you know now of any archives to do with Jansky's work?

Reber

That's what I'm getting to. So, Beck had a lot of records too. The electronic gear was different but apparently the same Leeds and Northrup recorder using the same charts. And according to him there was what he called a red barn. And his records were stored in the red barn. And these records of his, Beck's, were in cartons placed alongside cartons which contained Jansky's records. And he recalls very positively that they were both there. Now the year I don't know.

Sullivan

But this was back in the early ‘60s?

Reber

Oh, further than that, before 1949.

Sullivan

Well, he told you this around 1960. He recalls that they were there around 1949.

Reber

Yes. Maybe in the middle ‘40s. In the Bell Labs Journals there are a number of papers on antennas and propagation where Beck has his name attached. I think Beck is still alive.

Sullivan

Well, I was just checking that as a matter of fact. Do you know if Friis is still alive?

Reber

I think so, he was a few years ago.

Sullivan

I haven't been able to find him anywhere. Penzias told me about Beck, let me see if I can find that. Yes, now living in Florida. I haven’t been able to look him up but I guess I haven’t really tried. I should definitely try to talk with him, shouldn't I?

Reber

Well, anyhow Beck's records and Jansky's records were stored in what Beck called the old red barn which probably was the same thing that Southworth called the old house. And Beck then apparently was assigned to other work and he's no longer at Holmdel. And he then comes back, according to Beck, he came back some dozen years later. And this place where Jansky's machine was and the red barn or the old house now was a huge structure, a tremendous laboratory. Everything had been gone. So Beck tried to find out what happened to his recordings and of course, there isn't anybody there that knows anything about it because everybody there now is new. He hardly could find anybody that was there when he was there about a dozen years prior. And he gets apparently sort of annoyed, you know, he just gets the runaround, and so he hunts up a yards man or a grounds man, a caretaker, and questions him. And lo and behold now the mystery is solved. That orders had come from New York sometime about 1949 that they’ve got to clear this place preparatory to building a new laboratory. And so everything is cleared off and this structure of the old barn is demolished and everything in it is done for. And they were told to make a clean sweep and clean everything up. So this grounds man cleans everything up. And this particular bloke, whose name Beck told me, but I've forgotten, is the fellow that burned all the records. So they've definitely gone up in smoke.

Sullivan

What a shame.

Reber

The mystery of what happened to Jansky's charts is now solved but this, of course, merely brings forward another mystery as to how this kind of a thing happens. Now, I'm telling you what Beck told me and if you want you can see Beck and confirm it. Now, if Friis hears this, he's not going to like it, because I think he was the guy in charge, but I have nothing to do with it.

Sullivan

Well, these things happen, they're a shame.

Reber

Because I think I brought this up with Beck on the basis of what about Jansky's records on Jupiter. And then he told me what I've just told you.

Sullivan

Yes, I calculated that Jansky would have easily been able to see solar bursts or Jupiter bursts.

Reber

Sure.

Sullivan

But of course it was solar minimum so he was hurting there. But that helped him actually because he didn't have all this interference.

Reber

Sure.

Sullivan

Well, let me ask another thing, do you know how Jansky took your work? Was he sort of glad to see finally someone following it up?

Reber

Oh, I think so. Sure. The couple of times I met him he complimented me on what I'd been able to do and sort of wished he'd been able to do it, but that was all.

Sullivan

Did you see yourself as following in the footsteps of Jansky?

Reber

Oh, yes.

Sullivan

It seems that way.

Reber

Oh, definitely. I mean if he hadn't made the discovery certainly I would have never undertaken anything like that. It would have been foolish. You have to remember at that date I didn't know anything about Lodge or Edison or Nordmann, those all came to light much later.

Sullivan

Right, I think finally when the bibliographies were together after the War. While we're talking about Jansky let me ask you, in 1948 or '49 in Sky and Telescope you published Jansky's measurements in the form of a contour map on the sky. Now where did you get the data to do that? Was it only what he published?

Reber

If you look through Jansky's papers, he gives one 24-hour period of very clear data.

Sullivan

Yes, I know that figure.

Reber

And I scaled that stuff off and converted to galactic coordinates and that's it. That's where it came from. Look on that date [Sullivan: in Sky and Telescope figure] and it's the same date that he did.

Sullivan

Right, that's what I figured but I wanted to make sure. And also as far as Jansky's antenna pattern, did you make a detailed calculation of exactly what it was or just an estimate?

Reber

In the correspondence I had with Jansky he gave me the parameters, that is the polar coordinate diagrams, both vertical and horizontal.

Sullivan

He only published the horizontal one. He never published the vertical one.

Reber

Well, he gave me both.

Sullivan

I see.

Reber

Including the ground reflection coefficient. And so I computed them both. I still have those. As a matter of fact I looked at them within the past few weeks, those diagrams and all that stuff that Jansky gave me, formulas and everything. And the pattern is the same 30° wide in azimuth, but in the vertical it's about 60° up here and about 20° here.

Sullivan

Yes, you quoted 37° I think, at one point.

Reber

Something like that.

Sullivan

It's asymmetric, too, isn't it? In the vertical direction?

Reber

Oh, yes, because it doesn't come down to the ground. It can't. 37° half power beam width I guess, but that's not from the ground. There's about 15° there from the ground.

Sullivan

Right. I've been trying to re-do all this but it seems like you've got the information I need, like the ground reflectivity and all that. Another question about Jansky's paper I've never been able to figure out is that he quotes the end of his first paper, "That the maximum signal that he got for this strange hiss was .39 microvolts per meter." And that maximum seems to be far more than any of his traces, or that anything else he talks about. He just adds this sentence on at the end. I can't make it tie in anywhere. Do you remember anything of this as to what that means? All the other values he quotes seem to be much lower than that.

Reber

I wouldn't know.

Sullivan

Well, maybe I can show you the paper after we finished and it might ring a bell. I wanted to ask you, do you have a bibliography of all of your papers?

Reber

No.

Sullivan

I've put one together as far as I can do.

Reber

That list of stuff that's at the bottom of the 1958 paper is pretty complete. I don't think much has been left out.

Sullivan

Ok. Another question here about the early days which will get us into this article on, "Early Radio Astronomy at Wheaton, Illinois," [Sullivan: Proceedings of the IRE, 1958] and I have several questions. I have contacted a fellow named Lutz that you apparently wrote to. He was at Indiana I think, S. G. Lutz.

Reber

How do you spell that?

Sullivan

L-U-T-Z.

Reber

I don't remember. Go on. What did I say?

Sullivan

He was an expert on microwave tubes at Purdue. And I was told that he was an early radio expert, but I didn't realize that when I called him up he would actually have had some contact with you. Apparently he received a letter from you around 1937 requesting help in building a close-spaced diode, so you could do this high-frequency work. And he indeed was doing research in this sort of thing. He had the technology, but according to him himself he was uncooperative because you would not give the purpose of your project. And he says he really regrets now that he missed his chance to help because he says that he's a little bit on the wild side himself, that he always likes to go for these far-out projects. And that all he can deduce is that you wouldn't tell him because then you would be branded a nut because it would be sort of like interstellar communication or something.

Reber

I don't remember anything about that.

Sullivan

You don't remember this at all? Do you remember similar or other attempts of trying to get aid from people and sort of getting rebuffed because it was too wild an idea?

Reber

Obviously I did write to this gent if he's got my letter. And the reply I got obviously was negative, and so I've forgotten it. I probably wrote to other people. There was an article in some German magazine where they built a diode that had a glass bellows that could be expanded and contracted slightly to change the spacing between the anode and the cathode. And I wrote to this German concern, Telefunken or whoever it was, requesting would they build one for me. And they wrote back in German, which I had translated, that they would. But they wanted $200, which was a tremendous price. You could buy a real good used car for $200 in that day. And so that was the end of that. Now beyond that I don't remember.

Sullivan

Well, I suppose then your main source of equipment and so forth was what you could get from the company where you were working at the time?

Reber

That's right.

Sullivan

You could borrow stuff temporarily and...

Reber

I was in a preferred position, that is, I was in a good location, not living in a Chicago flat or something like that. That is I had this home out in the suburbs, which wasn't as good as a country home but it was open and spacious with some room there to do something. And I was not stamped upon by relatives. I worked in the city in the engineering departments of radio manufacturers and had access to what was at that day the best electronic equipment available. Some of it was useful, some of it wasn't. The main difficulty was that the frequencies I was interested in were not the kind of frequencies used by the electronic test equipment. But to the extent I could use it, yes. And I don't know how things are today, but they were pretty liberal, i.e., I could come in there on Saturdays, I had a key and I could come and work in the shop and build things, stay at night, and that kind of stuff.

Sullivan

By the way, was this home where the antenna was, was this your old family home? Did you continue to live there?

Reber

No, really. The old family home was 225 West Wesley Street. Well, about 50 yards away on the next street, this was an open square, there was another house which had been built by my parent apparently to live in when they were married but they never did [Reber: by my mother as an investment in 1917. My parents built a third house three blocks away but only lived there a few years.] They came to live with her folks who I gathered were getting on in years. And so I was brought up in the old home while the one that they had built for their use was apparently rented and we only moved over there quite many years later, about 1932 or ’33 [Reber: 1934].

Sullivan

But you did live there during this whole time?

Reber

On this square, yes.

Sullivan

What I'm trying to get at you were living right where the antenna was?

Reber

Yes.

Sullivan

And you say all this property now belongs to the Illinois Bell Telephone Company?

Reber

That's right, we sold it to the Bell Telephone Company.

Sullivan

But the houses are not there anymore, I take it?

Reber

Oh, the houses were moved. The houses are still there, at least last time I saw them a dozen years ago. They've been moved to another location. In other words they're still in existence.

Sullivan

You mention here [Sullivan: Proceedings of the IRE, 1958] that, when you were doing your ham operating, that on quiet nights, "It was always possible to make the receiver quieter by taking off the antenna." Do you have any more ideas as to whether that really was cosmic noise or not?

Reber

I don't know. The reason I took off the antenna was simply when you put the transmitter on the air, I had an antenna-disconnect switch.

Sullivan

I see, so it may or may not have been. You came upon the idea to build a large parabolic reflector and I'd like to ask you how did you come to that idea? I think that this dish must have been the largest of its kind, in the world.

Reber

It probably was at that day.

Sullivan

And I presume that radio engineers had built some small ones but was it all completely your own design work on how much the thing would deflect, and how accurate it had to be, and what the best f/d ratio and all this sort of thing was?

Reber

Well, it wasn't that detailed, but the f/d ratio, I think I explain in there, was determined by the pattern that came out of the end of an open wave guide. And so I decided that it had to have, whatever it was, 6/10ths f/d ratio.

Sullivan

So it was determined by just the feed then?

Reber

That's right. And as far as the rest of the structure was concerned it was expediency, i.e., the longest four-by-two's I could get in the local lumber yard were 20 feet long. So without having to splice, how big a framework could I build in which the longest member was 20 feet. And that turned out to be something that would hold about a 32 foot dish. That's all.

Sullivan

Amazing. And you talk about the frequency that you observed was determined by the size of the drum that you got for the first high frequency stuff.

Reber

Sure. For all these things there was nothing else to go on. There was no reason why any frequency should be better or worse than any other frequency.

Sullivan

But the amazing thing to me though is that your 30 foot antenna looked very similar to this 30 foot antenna here that we've been talking about that now is at Battelle [Northwest, Richland, WA.].

Reber

Yes, except that's got a shorter f/d ratio.

Sullivan

Yes, but not terribly different.

Reber

No, not different in great amount.

Sullivan

But it seems like you happened upon it by chance in what now is known to be the right design, or the optimum design.

Reber

Well, I don't know, but supposing you had an open selection of choices. You could have something which was very deep. It was obvious from the pattern that came out of the end of the wave guide, that a very deep one wouldn't be suitably illuminated. So that was out. On the other hand, supposing we had something very shallow. This then has very long focal length. And unless very long focal length had some particular merit, it was going to be a difficult thing to build. So between these two you came up with sort of a compromise. And that what it was. That's all.

Sullivan

I see.

Reber

Most of these thing people try to read too much into, i.e., there wasn't a lot of intelligent, deep, theoretical thought on these things. You had all these various options and you sort of shuffled them around and came up with one that looked pretty good.

Sullivan

Well, I think the point is that you had a very good feel for what...

Reber

Well, maybe so.

Sullivan

The average person would have come up with a very different set of options that wouldn't work.

Reber

In other words shuffle them around and maybe not come up with some satisfactory.

Sullivan

Right. Now, you say here, "I conceived the idea of using a single dipole inside a short length of wave guide at the focus of the mirror." Like I say, presumably there had been smaller antennas before that had been illuminated with a feed and so forth so that was not an original idea. You just scaled it to a larger size, is that correct? What were the unique problems that you had to face?

Reber

I don't quite know the answer, but it was apparent you had to have some kind of a collector device which would collect from the direction you chose to look at and exclude radiations from all spurious directions. And spurious directions weren't going to be limited merely by the diffraction pattern, but they were going to be limited by what was called "leakage" coming in not through the dish but around the dish.

Sullivan

Spillover is what we call it.

Reber

And so the antenna itself, the actual pick-up, had to be in some kind of a case or some kind of a box which would shield it from the surroundings. That's really all it amounted to.

Sullivan

What about the accuracy of the surface? Was it obvious that it had to be accurate to a 10th of a wavelength, or something like that?

Reber

Or a quarter of a wavelength, yes. So it was built as accurately as possible, but in the meantime, you see while this was going on, I was doing those experiments with a magnetron tube. And it became apparent that the shortest wavelength to which I was going to have any access was on the order of 8-9 cm. A 10th of a wavelength like that would be maybe 1 cm, which is say 3/8 of an inch, and so the overall accuracy was within 3/8 or a 1/4 of an inch, that would be all that would be possibly needed. And that was fairly easy to achieve because all these ribs, I got all those cut to ± a 16th. They were easy to cut out. And then I never did know what the accuracy of the dish was when tipped, but when it was pointed straight up- see there's a flat plane, reference plane, that the ribs are fastened to. And that reference plane was set up accurately to about ± a 16th or so by washers.

Sullivan

Shims, you mean?

Reber

Yes. So you had that reference plane leveled up.

Sullivan

Then you referenced your parabola to that plane?

Reber

Exactly. So supposing there was a 16th error there. Then there might be a 16th error in the vertical stays, rods, there might be another 16th error in the ribs, perhaps another 16th in the bending. So it was reasonably estimated to ± 1/4". That would be good enough.

Sullivan

Well, that would be a maximum deviation. They would normally not combine all together.

Reber

Oh, yes, I see what you mean. Yes, it would be a maximum there. The average would probably be a lot, maybe an eighth. If you take that 1/8 inch and divide it into 32 feet, you have a pretty fair size sum, i.e., I think that's what they characterize dishes on now, the ratio of the average error to the diameter.

Sullivan

Right. But now I haven't asked you perhaps the most fundamental question; can you give me any insight into what in the world came over you to embark on such a huge project, in your back yard essentially?

Reber

It was pretty big, true. But I was already convinced in the beginning that there was no sense in fooling around with something small.

Sullivan

Because of the resolution?

Reber

That's right. And the ability to pick things up, pick energy up. So it had to be as big as I could possibly handle. That's all. The reason it wasn't 50 feet was that I didn't have the wherewithal either financially or mechanically to build anything bigger. That's all.

Sullivan

But still this was taking up all of your spare time for many, many years.

Reber

Oh, yes.

Sullivan

You must have committed yourself to this essentially.

Reber

Yes, that is I took a summer off and didn't do anything else.

Sullivan

That was the summer of '37, I think?

Reber

1937, yeah. About the time I changed jobs, I think I shifted from Stewart Warner. I left Stewart Warner and took a summer off and then I went back to work. You see, Chicago was a very large city and also was at that time practically the center of the radio industry. And there were a lot of different radio companies. It wasn’t going to be difficult to find another job if I couldn't get one back at Stewart Warner.

Sullivan

And so you took a summer off precisely to erect this antenna?

Reber

Exactly. I was much younger then and I used to get up early and work from seven in the morning till seven at night. I don't do that anymore.

Sullivan

Well, like you say, it's very good that you wrote this down. You have all the details about people helping you to build it. Well here it is, "The entire job was completed in four months from June to September '37." And you talk about the local inhabitants were worried that the machine was collecting water and controlling the weather and so forth.

Reber

There were all kinds of unintelligent speculation, a lot of different kinds of things. I don't remember what they all were. Those were some of them.

Sullivan

No matter what you said, I suppose that they wouldn't believe you.

Reber

Yes. I don't know if I mentioned in there but people used to ring the doorbell and introduce themselves or maybe not even bother to introduce themselves, and say that they were passing through and they would like to know what that thing next door was.

Sullivan

You mention that pilots used to go out of their way to fly over this thing.

Reber

Oh, yes. Probably from the air it was a curiosity too. They'd circle around, and around, and around it looking at it.

Sullivan

But I suppose that the neighbors more or less just dismissed you as the local eccentric that was building this thing in his back yard. Or is that being unfair?

Reber

Oh, yes, I don't know, if they were particularly interested. I was just one of the local boys there, you know and I was a radio amateur, and well, I was not feeble minded, but sort of eccentric.

Sullivan

A radio amateur gone amuck.

Reber

That's right. I don't recall that I ever had any particular encounters with them good or bad, that is they didn't attempt to interfere with me nor did they attempt to assist me.

Sullivan

Except you got people to help you with certain critical stages where you needed labor and these are just friends, I guess.

Reber

That's right.

Sullivan

Also, another amazing thing to me is the fact that you had a hole there so you could have had a Gregorian focus if you'd wanted to.

Reber

Yes.

Sullivan

Did that idea of this come from optical work?

Reber

That's all. I don't know why I put that down here [Sullivan: in the article] but I thought all right if this thing is being built it better be built so there's not an obstruction in the middle, just in case I wanted to put my electronic apparatus at the bottom of this thing and put on a secondary, just in case. You see it wasn't feasible at the later lower frequencies but at those high frequencies, around 3000 megacycles, it would go through a 2 foot hole. Well, as an engineer you design things slightly over, i.e., so they have capabilities somewhat beyond what the demands are going to be, just in case the demands are slightly underestimated. It's just conservatism.

Sullivan

So that's what you were doing?

Reber

That's all. It was never used.

Sullivan

And now the antenna, as you say, well, first it went to Sterling, Virginia when you went to NBS. Now, was there any research done with it there? This is getting ahead of the story a little bit.

Reber

Not really. I went to NBS because there wasn't anything else offering really, I had some misgivings about it at the time as I couldn't quite understand what the National Bureau of Standards had to do with radio astronomy. After I'd been there for a while it became apparent that I was to be part of one of the internal empires, you might say. And the justification for my existence was that I was supposed to make observations of the radio waves from the Sun to be used as an index of solar activity. The solar activity would then be used to predict the conditions of the ionosphere which then could be used for predicting communications circuit performance, pretty far-fetched. But in any case, that was the justification for my existence.

Sullivan

And as part of the deal when you went there they said you could bring your telescope along and you'll use that?

Reber

That's right.

Sullivan

And what did it ever do in Sterling, Virginia?

Reber

While I was at the Bureau of Standards it didn't do anything. After I left it was used by two people whom I've since forgotten. But anyhow, it must have been 1952 by this time, these fellows had my dish set up there in Sterling, Virginia, and they did a Moon echo experiment with a transmitter at Collins [Sullian: Company] Cedar Rapids, Iowa. And that got published somewhere, I think in the Proceedings of the IRE. And they sent some signals up, 500 megacycles or 300 megacycles, or something like that at Collins and used my dish to pick it up from the Moon. And they decided that with this particular set of physical parameters that the circuit was suitable for hand telegraphy. And they encountered severe fading. Apparently the Moon liberates and this liberation was enough to cause some multiple scattering points to add and subtract. I don't recall the fading rate, but it was on the order of several fades per minute. And as far as I know that's all that amounted from it.

Sullivan

And when was it finally transferred to NRAO?

Reber

Well, I left there when they decided they were going to move everything to Boulder, Colorado. A lot of other people left. And they hired some contractor to tear everything down and lug it out there to Boulder, Colorado. So it was lugged out there.

Sullivan

Oh, it went to Colorado, too.

Reber

Oh yeah. It was taken apart along with a lot of other stuff and lugged out to Boulder, Colorado. And at that point some of my equipment disappeared under circumstances very similar to how Jansky's charts disappeared. There were people in one place issuing orders without any idea of what the consequences were going to be, and other people carrying them out without any idea of what they were doing. In any case, the dish was dismantled and taken out there. Nothing was ever done with it. All the pieces apparently lay in a big heap for several years. I don't know when they went out there, maybe 1954, something like that. Well, in the meantime NSF got started and then they developed NRAO. And they finally got some land out at Green Bank about 1958. And Dick Emberson or Berkner or somebody thought that it would be a good idea if they could get my dish put back together again. So they found out the remains were at Boulder, Colorado. And by that time I had finished some of my work in Tasmania, so I agreed to come back to Green Bank and help them put the thing together. So I did. And in the meantime they had lugged everything from Boulder, Colorado to Green Bank, West Virginia. But it had laid out there too long. As I mentioned, when it was taken apart in 1947 it was just as good as when it was put together. But after the stuff had laid out in the open for 10 years or so it wasn't. And all we were able to salvage out of it was the metal pieces, which all had to be sand-blasted and cleaned up. So all the metal pieces that are at Green Bank are original. But the wood pieces were hopeless. They were done for. But I fortunately had all my drawings. So I went back to Wheaton and got my drawings and they bought new wood and this time we impregnated them with this copper compound which is used in park benches to prevent rot or reduce rot. And all the wood, pieces were refabricated. And they had succeeded in getting oh, maybe a half of the sheet metal for the dish. And the other half had departed, nobody knows where. People had helped themselves. And the remaining half in existence was in bad order. A lot of it had been heavily creased and dented and rusted, torn. So there didn't seem any point to try and use that old stuff. And we bought all new skin for the dish, but this time we bought it out of aluminum instead of galvanized iron. But it was all fabricated to the same design.

Sullivan

So now you're saying, is there any of the metal...

Sullivan

So continuing with Grote Reber on 25 October ’75 and he told me that at the Green Bank dish the metal support structures are original, but the surface is new and all of the wooden parts are new. So continuing through your 1958 article about the early days, you say you first tried at 9 cm and your reasoning was that, if it was thermal radiation, a high frequency should have much stronger signal as well as getting a higher resolution. And you say an RCA-type 103A endplate magnetron was acquired for general testing. I wanted to ask you when you say "was acquired," does that mean you were able to borrow one from the company or did you always have to go out and buy all this stuff?

Reber

Circumstances were different in that day, in that we had salesmen that came around and try to sell their products, and these were pretty able, intelligent, and aggressive people who knew their product, they knew their company, and they had good liaison with not only the management but with the factory. Today you get salesmen that don't know their products; they don't know anything, see. They can't even find anything in a catalogue. Well, in any case, in that day there were these salesmen that came around and they were pretty good. And in the local radio industry there’s a fellow could come around in the morning and you wanted a special kind of switch or a capacitor or something, and by God frequently you'd get it in the afternoon. He'd just ring his factory and say now, "Modify so and so and so and so and I'll pick it up." Well, in this A103 magnetron RCA was, of course, sending its reps around. And I'd talk to them not only about what they were trying to sell Stewart Warner, but other things which they might have. And they were pretty able, that is they wouldn’t telephone New Jersey, but in a few days when they were back they'd have some literature for me about some experimental thing being made in the Harrison Tube Labs or something. And one of these things turned out to be this magnetron, and so I asked them how much they wanted for one and they already had a price, that experimentally they'd sell them, I think, for $30 a piece or something. So I bought one. But I found out about it through this preferred position in that I had good contacts with the electronics industry.

Sullivan

It really was critical in doing all these experiments.

Reber

That's right.

Sullivan

Going back to the dish momentarily what was the total final cost of the dish? Did you ever add up the figures?

Reber

I don't remember exactly but it was on the order of a $1,000, not very much.

Sullivan

Which is incredibly cheap, even at that time because all of your own labor was put into it.

Reber

Well, yes. But think a $1,000 would have bought a brand new Ford car.

Sullivan

But what kind of a dish can you build now for an equivalent of a Ford car?

Reber

Nothing.

Sullivan

That's what I mean.

Reber

Yes, that's true. In other words for the price of a Ford car today you couldn't get anything.

Sullivan

Ok, moving on further, you talk about a Barkhausen tube was tried and you say, "The vacuum tube construction work was done by the glass experts of the University of Chicago." I was wondering how you arranged that. Was that through being a graduate student there?

Reber

Yes. They had a fellow whose name I don't remember anymore, but they mainly had built things like flasks and pipes and junk for the chemistry laboratory.

Sullivan

All old physics departments used to have glass blowers.

Reber

Yeah. The typical kind of a glass lab a university would have. And I got all the metal parts and just had them put it together. And incidentally, they built this small diode, too. I don't know whether that's mentioned in there or not.

Sullivan

Now, we come to the summer of '38 when you tried these 3300 MHz observations and as you say all this was rather dampening to the enthusiasm when you didn't get any signals. I can imagine that's true. But nevertheless you continued to go on. Was the idea that you had invested so much in the dish that you certainly weren't going to give up with just the first receiver?

Reber

Well, partly that. But don't forget I had in front of me Jansky's results. So it wasn't just a question of hunting wisps in the dark, that is here was some positive evidence. True, I was doing different things. The mere fact that I got nothing didn't necessarily prove that nothing was there. Here was very good evidence there was something there. Now I was at a very different wavelength, by some 40 times or something, and consequently what came out of this, I think as I mentioned, was simply that the phenomena certainly didn't follow Planck’s black-body radiation law. Well, nobody knew! Nobody had any idea about what the law might be, I think, I say it might even be an inverse one. So I made a bad guess. That's all.

Sullivan

And you knew that if you went low enough eventually you must detect it, so it was a question of how high could you detect it at.

Reber

Exactly.

Sullivan

Now this is a general question about all of this. I gather that you've been through your archives recently. Are all of the log books and everything, are all of these things still existing from these early observations?

Reber

Oh, yes. I've looked at a lot of them very recently.

Sullivan

You just mentioned that many of them are in Tasmania, do you have some there now?

Reber

Yes.

Sullivan

They're all in Tasmania, including old equipment.

Reber

Everything. It was in storage a long time in Jersey where I couldn't get a hold of it or use it and when I decided I was going to be down there for a while, I had the Research Corp. send everything down there. They were paying big storage fees on the damn stuff, it wasn't doing anybody any good and nobody could get any access to it. So all right, let's quit pumping money down that drain and bring it down to where I can do something with it. This was a very fortunate thing since they [Sullivan: NRAO] wanted me to give this lecture [Sullivan: NRAO Jansky lecture, 1975] on all this old stuff. And I had the opportunity now to dig it out and look at it and examine it. And, as I say, most all of it is in quite good shape.

Sullivan

Great. The old photographs that you took of the antennas and the various receivers and stuff? Well, I've got to get down to Tasmania somehow and see all this.

Reber

I have a couple I’ve brought with me. A funny thing happened but some of these old photographs taken with this camera that was given to me when I was maybe about 12.

Sullivan

Oh, the one you told me about, yeah.

Reber

And peculiar enough it's an ancient camera that you can't get the film for anymore, but technically it has a very good lens. It has a long f-ratio. And so it took very sharp photographs and all these old negatives were very sharp, even the ones taken indoors. Except for a few that were taken by my good mother. She pressed the button with a great vigor and so the damn things got blurred. And I saved them because I'm a pack-rat. And just in the past couple of months an article came out in Science about de-blurring photographs, so I pulled that article out and I have taken out two that I thought might be worth reconstructing. And I folded them all together in an envelope and when I get to Green Bank I'm going to have the Director there write to this bunch and say would they de-blur a couple of these photographs.

Sullivan

Because they are of historical interest.

Reber

See if I get a positive response on that.

Sullivan

That's beautiful. Ok, moving on here. So you have these photographs. You talk here about you had provision to rotate the drum to measure polarization if necessary, which I figure is sort of an amazing step also. Were you expecting that this radiation might be polarized?

Reber

Not really. But you see, going to school I learned about polarized light and in optics in astronomy by that day there had been some polarization measurements, particularly in relation to the solar corona and so on. And so without having to go to a lot of complexity it seemed that it would be worthwhile to include in this general development some provision for checking polarization.

Sullivan

Did you ever make any such measurements?

Reber

No. You see it's easy, see this is circular, all you do is turn it.

Sullivan

And I suppose you have the very first records where you got a positive detection amongst your archives? I really would like to see that someday. Now you use the interesting term, "These preliminary results were published in 1940. The intensity was guessed at by noting the effective resistance shunts across the first tuned circuit. No calibrated signal generator was available then." Now by saying "guessed at," I think you're trying to imply that it was very crude, do you mean an order of magnitude sort of thing?

Reber

Yeah. Well, what happened is that in order to get anything lined up you've got to have some signal generator. So what I built was an oscillator that was really adjustable. Now this is different from tunable. So I adjusted the oscillator to some frequency which I felt was suitable, using a Lecher wire, and then I tuned the receiver to that oscillator. And that receiver shown there...

Sullivan

In the 1940 article.

Reber

That receiver has multiple single tuned circuits, so you just synchronized them all. So that was easy. And then you came up with an output depending on the amount of fluctuation noise in the first tuned circuit. So then you put a resistor across the first tuned circuit and noted what happened to the output. And from this you could guess what the sensitivity was going to be. That's all. So it was a guess, you know, an order of magnitude.

Sullivan

Right.

Reber

That was all built before there were any results. So I didn't go overboard buying hundreds of dollars worth of test gear or building very fancy test gear.

Sullivan

You didn't consider it that important to pin down the negative result that accurately.

Reber

No. After I got some results, then that changed the whole picture. Now that we got some results, let us find out with more precision just what all this is about. And then I built a real good signal generator that I think I mentioned.

Sullivan

Yes, right.

Reber

I've got pictures of that. None were ever published, I think, but I took some pictures.

Sullivan

Ok, now you mentioned that the next paper published in '44 included a polar diagram of the antenna pattern taken on the strong source in Cassiopeia. And indeed that's, as we talked about, the best way to get your antenna pattern. But did you realize that at the time? Apparently not, because then you wouldn't have been quoting these small beamwidths.

Reber

Probably not, at least not in the beginning.

Sullivan

Because you did realize, of course it wasn't known that Cas was a point source in the beginning.

Reber

No.

Sullivan

So I think that's the trouble.

Reber

The antenna pattern was certainly no bigger than that. No, I think in honesty I didn't realize that Cas was telling me that this was the antenna pattern.

Sullivan

That it could be no bigger than that, like you say?

Reber

It could be no bigger, yes, because those other sources down the line that were shown on that same set of contours were all bigger than Cas.

Sullivan

Right, but it still could have been smaller, as you thought it was from your models?

Reber

I suppose.

Sullivan

So it was consistent with what you thought certainly. If you'd found a source in the sky that was only 1° in size then you would have known that something was astray.

Reber

Yes. So I didn't find anything smaller than what the theoretical pattern should have been.

Sullivan

Right. And as you told me in the letter, apparently you went astray using some models. Maybe you can tell me again exactly how you tried to determine the antenna pattern.

Reber

Well, I don't remember the details of that, but it wasn't done at that frequency, it was done at the microwaves.

Sullivan

With the 9 cm?

Reber

Yes, with the 9 cm thing, see. And I had a crystal detector in, and the crystal detector was a very non-linear device. These things have more importance today than they did then. At that time I didn't worry about these matters. The question was whether I could get anything or not.

Sullivan

Right.

Reber

And we’ll worry about all this kind of stuff once I get something to measure. There was nothing to measure.

Sullivan

No, I agree with you totally. But you can see, of course, where it's of interest now to try and see exactly how it developed. And especially, for instance, when you had some bumps that you thought were the Andromeda nebula, but in fact...

Reber

They were just drifts.

Sullivan

They were narrower than any your antenna could possibly have picked up.

Reber

That's right!

Sullivan

As Van de Hulst pointed out. So it would have been useful to you in that respect anyway.

Reber

I think I tried to correct that in here somewhere, didn't I? It's mentioned somewhere that...

Sullivan

In this article?

Reber

Yes, towards the end.

Sullivan

I don't remember. The next point I have here is that when you detected the Sun in '43 that if the radio source were a size of the optical disk, a half a degree, that you'd have a temperature of about a million degrees. And you say this had no meaning at the time. And I think it's also true that you did not point it out at the time when you made your measurement.

Reber

No, no I didn't.

Sullivan

Did you realize this at the time, did you make any such calculations at that time?

Reber

No. I pointed out that it had an intensity similar to what the intensity was in Sagittarius.

Sullivan

Right.

Reber

And as far as converting it back to temperature on the disk, no. I just pointed out at that time that it was far in excess of anything that might be expected. That is, orders of magnitude.

Sullivan

I wanted to ask you: now working at 480 MHz you talk about, "Even before the four-stage amplifier was finished, it was clear that it would be rather ineffective. By using special dispensation, I secured some GE 446B lighthouse tubes in ’45." What does that mean?

Reber

Well, see this was just at the end of the War and most all of this stuff was still classified in some manner or another. And there was a very limited production of these lighthouse tubes for certain radar things. They were used, I believe, as local oscillators. And consequently they weren't an open market thing. But again through my connections in the radio industry I was able to get these things, the same as I got those orbital beam multipliers. And I got others, there was a sample I picked out of boxes called a beam deflection mixer, which was never used. But I got an assortment of this stuff through those channels.

Sullivan

When you first picked up the burst from the Sun and this was in '46 I think, summer of '46, is that right? [Sullivan: 21 November 1946]

Reber

I guess so, sounds like it.

Sullivan

And this is what you were describing to me earlier about well, about that time anyway, when you had some visitors down there and the bursts came in the sidelobes.

Reber

That's right, solar activity was rising.

Sullivan

Were you reading Nature at that time? Had you seen Hey's thing and the very early thing Pawsey things?

Reber

No. I didn't learn about Hey until after I got to Washington in 1947 or 1948.

Sullivan

Really, I see. So you were operating completely independent.

Reber

Apparently.

Sullivan

Also of Pawsey's group?

Reber

Yes. I don't seem to remember much about that. I'm pretty sure I didn't learn about Hey until later. If I did it was just before I left Wheaton. When did Hey publish his stuff?

Sullivan

Right after the War ended in early 1946. And Pawsey's first paper was also in early '46, same with Ryle.

Reber

Well, I knew about it but I can't tell you the date. I don't remember just when it was. It may have been a year afterwards.

Sullivan

But it's certainly true that when you first detected the Sun in '43 that you didn't know about Hey or Southworth.

Reber

No.

Sullivan

Because you didn't have access to those reports.

Reber

No, I didn't have access to anything. You see, several people could be called the discoverers of solar radio waves, including the Germans, all independently.

Sullivan

Sure.

Reber

And they all came to light later.

Sullivan

Right.

Reber

And Southworth wrote me that the only reason he was able to get that article of his published in the Journal of the Franklin Institute was because I had already published mine.

Sullivan

I see. That was the final reason the military let him do it?

Reber

Yeah, that is he had written up all this stuff and attempted to get it published. And it had been knocked back by the military. That must have been shortly after he discovered it, whenever it was, late '42. And then my stuff appeared in 1944, and at that point then he went back and made further representations to the military and he said that they finally condescended to allowing him to publish it provided he expurgated all the details on the equipment. He was very annoyed, undoubtedly.

Sullivan

Right, but if you look at his paper, he was very clever, you can read off on the charts and still see exactly what the frequencies are and from the frequency and knowing the drift scans he gives, you can deduce the size of his antenna, which he wasn't supposed to mention either. And you get an idea of his sensitivity also from these charts, so the information is there.

Reber

Yes, you need to know how to read it.

Sullivan

But he got past the censor, anyway. Now you mention here that Van de Hulst visited you, I guess, in the autumn of '45. Can you tell me about that?

Reber

Van de Hulst was in Holland during the period of the German occupation and I gather things were sort of unhappy at that period. I guess the astronomers had to go out and dig in the gardens to raise vegetables to get something to eat, on that general level. Anyhow, according to Van de Hulst I gather it was Oort that was cognizant of this transition in the hyperfine structure...

Sullivan

Well, no. I've gotten that whole story from Van de Hulst. I can tell it to you.

Reber

Well, that's all right.

Sullivan

It was actually he that found it. Oort said, "Try to see if you can find a line," and Van de Hulst went out and actually found the transition and worked up the details.

Reber

I see. Well, in any case, he showed up shortly after the War, in late '45 or early '46.

Sullivan

At Yerkes?

Reber

In Yerkes, yes. He was some kind of visiting scientist and he was making a tour of America apparently. He didn't come immediately to Yerkes, I think he'd been to Harvard, Princeton, a lot of places. And then he came out to Yerkes. And, of course, at that time the fellows at Yerkes were very cognizant of what I was doing. And so he hadn't been there more than a few days and they brought him down to me. I don’t remember who all came with him. It was two or three other people. And so at that time I was trying to build a 480 megacycle receiver that would get something and it was already evident that the sensitivity was going to have to be pretty good. And he wanted to know what I thought of the possibility of detecting something at 1420 megacycles and I took a rather dim view of it because it looked to me as though it was beyond the present technological capabilities. And then I tried to question him and it really was more an idea than a theory, that is here was this transition in hydrogen and there was hydrogen out in space and I couldn't get out of him and he didn't know whether this transition was going to show up in emission, whether energy was being fed into it or whether it was going to show up in absorption like Hartmann’s lines of calcium. And as to where to find it, finally he gave me the obvious answer, you look towards the center of the Milky Way. Well, ok, it's a theory of a sort, but not the kind of thing that you knock yourself out on. So I didn't do anything about it until quite a bit later. And I think I mentioned later I'd built some signal generators and stuff.

Sullivan

Well, let me first ask you, you say that if the line was going to be in absorption, it would be practically hopeless. If in emission, there might be some possibility. What was the reasoning for that?

Reber

Maybe not any very good reasons but you can always detect something better than you can detect nothing. That's all.

Sullivan

Ok, so you weren't thinking in terms of like we do now, of a profile where you compare off-frequency with on-frequency?

Reber

No.

Sullivan

You were just thinking of a single channel?

Reber

Did I mention how I was going to do this?

Sullivan

I don't think so. You talk about building the signal generator and that the GE lighthouse tubes would not be satisfactory, Sylvania tube. You have a multi-stage amplifier, "Provided the amplifier was good enough to detect the continuum, it seemed likely that a fairly strong absorption line might be detected. If the line were to appear in emission, then so much the better." Oh, I get the idea, that that's just a stronger signal.

Reber

That's all.

Sullivan

I see. It's not a matter of the contrast between on-line and off-line. "The entire set-up was never completed," because you moved away in '47.

Reber

Did I mention anything in there about an echo box?

Sullivan

Yes, you said, "It was intended to insert the echo box in the chain."

Reber

That's the tuned system.

Sullivan

Which would give you a resonance at 1420?

Reber

Yes. The idea was, coming here with your antenna, you go through a broadband amplifier. That thing ultimately got partially built with these rocket tubes, I think. I got, I think, 13 dB per stage and about, I think, 15 megacycles [Sullivan: bandwidth]. Anyhow, then this was to go into a diode detector, just conventional, then down through dc amplifier meters. That was for running the continuum. Now, if you could find the continuum, presuming all this worked, then you put a highly selective tuned circuit right in here. And this tuned circuit was adjustable.

Sullivan

So you had a filter?

Reber

That's right. And this echo box is nothing but a filter, an adjustable tuned filter. And then you would tune this filter along until you found a bump in the output. That was the idea.

Sullivan

I see.

Reber

And I took some pictures of that echo box just recently. It's pretty big, it's about this big in diameter and about that tall. It's one I got on the surplus market somehow, I don't remember the details now. But it was used in some military capacity which I don’t remember, or don’t know even. Anyhow, it had a Q of about 70,000. Now if you take...

Sullivan

That's a 50th of a MHz.

Reber

And divide that by 70,000, that's about 20 kHz. So we'd get pretty good resolution.

Sullivan

That's right. It would be just about right, very optimum.

Reber

I don't know. As it turned out, it would have been about optimum.

Sullivan

Lines are 100 kHz wide. But you had no switching technique there?

Reber

No. There wasn't going to be any switching technique.

Sullivan

So it would have had to be very stable to detect the one percent line, or something like that?

Reber

Yes. It probably would have had to be pretty stable.

Sullivan

Did you work at all in conjunction with the Dutch on this or was this also independently after Van de Hulst went away?

Reber

This was all built after Van de Hulst left.

Sullivan

So you just thought it might be a good idea to do and you might well have continued with it if you hadn't moved away?

Reber

That's right. There were a lot of conflicting things, that is the place I was living at was deteriorating. My parents had died and my brother wanted his money out and so did I. In other words we'd like to liquidate this place. And furthermore, the city was growing and they had installed an automobile parking lot next door and there were more and more cars in motion all the time. And the general environment was getting poorer and poorer to do anything like this. So there were these various pressures, you might say, to close up and get out. And the only place that was offering at the time was the Bureau of Standards. If these pressures hadn't been present, in the next year or so I would have finished this [Sullivan: 21 cm project] up. And one of the, well, promises I got when going to NBS was that I would have the facilities to do these things. It didn't materialize. So nothing more was done. It probably would have worked, I don’t know.

Sullivan

It had a good chance anyway.

Reber

But you can see this was not the way to do it, really. But I was in a rut, that is I'd built these other things in this fashion, with the wide band amplifiers. The way to do this is the way it's done now, with a superheterodyne and put the selectivity in the IF system.

Sullivan

Hindsight is always very easy.

Reber

People ask me about this microwave stuff in 1937-1938, what IF frequency I used. I didn't have any IF frequency. And they look at me, sort of blank like and I say, "Well, it was just a total-power detector output amplifier system." And the reason, of course, is there was no local oscillator. This klystron thing hadn't yet been invented.

Sullivan

That was during the War.

Reber

There wasn't any. There was no possibility of building a superheterodyne, see. There were only two tubes, one is this magnetron and one is this Barkhausen tube, and neither of those were continuous wave oscillators in the sense that we have continual wave oscillators. They are more like spark oscillators, i.e., they produced oscillations but they weren't a continuous wave, they were a broad spectrum of waves.

Sullivan

A continuous stream of sparks?

Reber

An old spark transmitter produced a bunch of transients which were independent oscillations around some center frequency governed by the tuned circuit. So, you got a flock of side bands. Well, that's all these magnetrons and Barkhausen tubes did, the same kind of thing.

Sullivan

And so a continuous stream of sparks, to make a continuous signal, more or less?

Reber

Yes. The Barkhausen tube, as originated by old Barkhausen, was a triode, where this was the filament and this was the grid and this was the plate. And this was made minus, and this was made plus. And you put a tuned circuit in here, between the grid and the plate with suitable blocking condensers and this grid, of course, had interstices in it and so an electron was attracted by the positive charge, but it went through a hole in the grid and came up here and then was repelled by the negative charge in the plate and fell back onto the grid. And if everything was adjusted properly, this time was equal to one cycle of this time [Sullivan: frequency]. But these things weren't all doing the same. Some of them, you know, maybe were coming up real close and some of them were coming up not so far because they have different thermal velocities. And furthermore, this thing wasn't symmetrical. Mechanically it was irregular. So it didn't produce continuous waves, only sort of like continuous waves.

Sullivan

Yes, I see what you are saying. Speaking of tubes and such, it just came to mind, the work of Potapenko. You may be interested that he's still alive. I talked to him in Pasadena last summer. He told me about the experiments that he had done with this fellow named Folland. But did you know about these in the ‘30s or did you only learn about them later on?

Reber

I think I learned about them later on. I remember now, I didn’t know about them at that time. The way they came to light was that after Keenan had been down there to Wheaton a couple of times and Greenstein had been along- see, Greenstein came from out there somewhere. Oh, did he? He was out there anyhow.

Sullivan

Well, eventually he ended up at Caltech, I can't remember exactly when. [Sullivan: ~1948]

Reber

Anyhow, I'm pretty sure I learned about them through Greenstein. Because Greenstein showed me some pictures that Folland or Potapenko had given him of an old Chevy or Ford or something.

Sullivan

Right, I've got copies of those. You might like to see them this evening, I have them with me.

Reber

Well, I saw those pictures from Greenstein and that's how learned about them.

Sullivan

I see. But you didn't know about them in the 30s?

Reber

No.

Sullivan

Well, I have a couple of other questions on your papers, the early papers especially. But are there any other points that I've missed that you'd like to comment on these early days? As to influences on your work or what was motivating you to... I think I've covered most of the major things.

Reber

At the University of Chicago a lot of professors down there that looked upon the students as a necessary nuisance.

Sullivan

That still happens.

Reber

But Arthur Holly Compton had a rather more benign look upon students.

Sullivan

He was the head of the Physics Department?

Reber

No, Henry Gordon Gale was head of the Physics Department. Compton was some kind of an honorary professor. They gave him an extra stipend.

Sullivan

Right, he was above it all.

Reber

Anyhow, he seemed to enjoy the company of young people in the fashion that most of the old fogies down there didn't. And so he didn't talk to just me, but he seemed to be interested in talking to all the young people. And he wasn't bigoted in the sense that some of those guys were down there, that is some of those fellows like Dempster couldn't think about anything except their damn mass spectroscopy. But Compton was interested in and liked to hear about the things that the young people were thinking about. And that didn't mean that they had to think if about what he and his group mainly were doing because what they were doing was high energy physics with the Cockroft thing. And Compton himself was doing some cosmic ray stuff and I wasn't interested in either one of them. But I remember we used to talk about things in general, and he had a rather open mind, compared to say Kuiper, in that Compton said, "Well, you know, we've got very limited senses, and that our comprehension of what is coming down from the sky is really quite limited." You remember in that day all we had was a few cosmic ray particles, which nobody knew where they were coming from, and light. And if our technology improves, we'd probably find that the Earth is being bombarded by a lot of different kinds of rays and particles which we have no comprehension of today. I thought this was rather an open outlook on life compared to some of the dogmatic things that you got out of the others. And I can remember discussing with him about science and scientists and what made a scientist go, that is why was a scientist a scientist? Why did he do these things he did? And I hazarded a guess that the reason the scientists were scientists was probably because science was today’s outlet for adventure. And that in the sixteenth century if you wanted adventure you joined Magellan or Columbus or Balboa or somebody. But those opportunities were long since closed. And that science presented an opportunity for adventure. And he countered with the proposition that he thought well, that was maybe part of it. Some people, he said, thought scientists liked science because it represented knowledge. But that wasn't true. That if all you were interested in was knowledge all you had to do was go down to the library, there was unending amounts of it down there. He sort of agreed that it was the adventure of the discovery of knowledge. In other words, this was the thing which pushed the science along.

Sullivan

It was the process.

Reber

It wasn't the knowledge in itself, it was the making of it. That was his opinion. And I thought this probably was about as deep an insight into the whole affair as any I had seen. I haven't forgotten him. I thought he was a very worthwhile influence at the university. It was unfortunate that he and some others down there got into loggerheads with the president down there at that time, they had several of them. But anyhow, they imported this young fellow Hutchins out of Princeton, and he looked down on scientists. They were a modern-day kind of alchemists that were degrading society. And that he thought that the intellectual kind of stuff which should be dispensed at a great university should be connected with the great thoughts of the great men of the past. And so he was going to teach courses in the classics, which he did, I guess fairly effectively. But he was just as anti and bigoted on his own classics as Dempster was on his mass spectrographs. And consequently he didn't know what was going on in the science laboratories, and cared less. And I'm pretty damned sure that Hutchins didn't know what was going on under the stadium when they were doing those things then [Sullivan: the Fermi fission experiments]. And not because he couldn't find out, but he didn't care.

Sullivan

Right, he had no interest.

Reber

And so there was a schism between the high management that was represented by Hutchins and the management of the more mundane physics and chemistry and the biology departments. Too bad but that's the way it was.

Sullivan

Amazing. That's all very interesting and of course, Compton was very right.

Reber

I thought that he was one of the better ones they had down there really.

Sullivan

Well, moving to some specific questions. In your Proceedings of the IRE article in 1940, you quote an upper limit for the Sun, you try to detect the Sun and you say you don't find it. And yet this level is about 1/4 of the level which you actually finally detected in 1943. Now, do you attribute that to the fact the measurements were so rough in terms of absolute intensities?

Reber

Probably, yes. If you've decided that's a quarter, I'll accept it.

Sullivan

Well, it comes out - it doesn't surprise you at all?

Reber

No, it doesn’t surprise me. It’s within a reasonable range.

Sullivan

Right. And I suppose that the upper limits that you give for other astronomical objects that you looked at like Mars and Venus and so forth, that those should also be corrected for the antenna size, beam size and that sort of thing? You were assuming the same parameters? Ok, here, I don't quite understand what you mean in this sentence when you say you've tried to get Vega, Antares, Mars, to no avail, "While some fine structure of radiation patterns seems to be present, the existing equipment is not adequate for its accurate resolution." What did you mean there?

Reber

At this stage I think I was still doing it by hand, wasn't I?

Sullivan

Yes, plotting it every minute.

Reber

Yes. Ok, if you look at all these little wiggles, see, that's what I called the fine structure.

Sullivan

Ok, and you're talking about really a fine structure in what we'd now call a drift scan?

Reber

That's right.

Sullivan

I see.

Reber

Today’s reading of it would say that it was a structure which was commensurate with the resolution of the antenna. That would be today's reading of it. The reading of it as of that time would be the wiggles shown in the curve. And these wiggles didn't repeat and so you couldn't say that these wiggles had any meaning.

Sullivan

Right. But then you also say though that the, "Equipment is not adequate for its resolution." Now you were thinking perhaps that if you had a larger antenna that the signal would become stronger?

Reber

I don't know, could have been.

Sullivan

Or do you mean that the sensitivity wasn't enough?

Reber

"While some fine structure of radiation pattern seems to be present, the existing equipment is not adequate for its accurate resolution. No conclusive measurements have been made on any of the extragalactic nebulae."

Sullivan

Well, maybe resolution here doesn't mean angular resolution. It means the resolution of the problem as to whether it's real or not.

Reber

That probably, let's see, "The equipment was not adequate for its..."”

Sullivan

"For the fine structure's accurate resolution."

Reber

Well, repeatability, I think, would be a better word.

Sullivan

I see. Not adequate to make it repeatable. In other words, it’s sort of down in the noise?

Reber

Yes.

Sullivan

I see what you are saying. Now in Fig. 2 [Sullivan: in ApJ 1940], I was wondering why these curves are so smooth. Were they made up of one minute dots also?

Reber

Yes.

Sullivan

And you just didn't show the dots?

Reber

As you can see, they're pretty darn straight.

Sullivan

So you just drew the smooth curve. Ok. Here's a small question, here you quote a 162 MHz frequency and in all the other papers you say 160 MHz. Do you remember how that came about?

Reber

No, I don't.

Sullivan

It doesn't seem to jibe with your Wheaton article either, but it's not an important question so don't worry about it.

Reber

I may have run some of these at 162 and I may have run some of them at 160. I can't tell you at this late date.

Sullivan

That could be also, yes.

Reber

Well while I'm thinking about it we were talking about been made on any of the extragalactic this hydrogen line and Van de Hulst and I found out later that this thing had been independently explored in the laboratory at Columbia by Rabi. You know about that?

Sullivan

He measured it accurately in '48 or '49, right. That was what Ewen and Purcell were working on. They had a very accurate frequency.

Reber

Yeah, yeah.

Sullivan

And Van de Hulst calculated 1411 MHz.

Reber

Something like that, yes.

Sullivan

Now in the 1942 in Proceedings of the IRE paper, all of these photographs, are they still existing?

Reber

Yeah. The equipment still existing too.

Sullivan

So if the photographs are worn, you can take new ones!

Reber

Yes. As a matter of fact I have. The only thing that is not existing is that drum [Sullivan: Figure 5].

Sullivan

Is this you up here [Sullivan: in Figure 2]?

Reber

No, that's one of my helpers.

Sullivan

Yeah, it didn't look like you.

Reber

This [Sullivan: Figure 3] is the rear axle of a Model-T Ford truck. So I used Model-T parts and these universal joints and stuff I think are all parts of Model- T's. And the splines that went into them and all that are parts of Model-T's.

Sullivan

This is continuing with Grote Reber on 25 October ’75.

Reber

During this period the Model-T's were finding their way onto the junk heap. And so that was a very abundant source of this kind of stuff. But if you went out to do it today, you couldn't find them because they all long since gone to melt.

Sullivan

And this was the declination drive essentially?

Reber

That's right.

Sullivan

And was it a hand-cranked sort of arrangement that you had?

Reber

There’s the crank [Sullivan: in Figure 3].

Sullivan

Right.

Reber

Doesn't show very well, but there's the handle of the crank and there's the shaft of the crank and then it bends over and slips on there and it’s a spline that allows the crank to be taken off so the kids can't crank it. We were only a couple of blocks from the school and the kids used to come in the afternoon and play on this thing, you know, like they play on a playground.

Sullivan

I love that point in one of these articles where you got a very southern measurement because the dish got stuck there in a snow storm and so you just took advantage of it.

Reber

That's right.

Sullivan

How did you get the dish unstuck?

Reber

I got a fellow at the local garage, a blacksmith that did some of this blacksmithing for me. Out in that small town they had a fellow who was sort of a general mechanic and he represented an automobile dealership and he did blacksmithing and this, that and the other thing. He had a steam engine that drove a lathe and things. And he was the fellow that helped me or in some cases did a lot of the mechanical work on all this metal. See, we bought the metal in Chicago from Steel Sales, and brought it out by truck and then sawed it up and drilled and bent it at his place, this blacksmith's. So I got this blacksmith to come there as soon as the weather got good enough in a few days, and we jacked this thing back up and put it back on the track. That's all.

Sullivan

I thought that was real ingenuity to take advantage of that. Let's see, page 376 [Sullivan: Proceedings of the IRE]. You said that, "Unfortunately the present method of scanning along declination lines makes it quite difficult to obtain good data beyond dec = + 45°." Why was that?

Reber

It's because just the Earth is going slowly. That's all.

Sullivan

But in fact you get more sensitivity because you get more integration time per beam.

Reber

Oh, I see what you mean.

Sullivan

I don't see why that makes it more difficult.

Reber

Well maybe that's a bad statement. Actually I can't say that it's true, because the data seems to be just as good up there, doesn't it?

Sullivan

Right. I thought it might be something to do with that when the dish got tilted past the zenith that you ran into problems of some sort.

Reber

No. I think it's just that since the Earth is turning so slow the records get spread all out.

Sullivan

Right, then the drift. So then actually the integration time is too long, really?

Reber

Well, if this is your baseline like that, it spreads everything way out and so it becomes more difficult to get these things off, get the ordinates. I think that's it.

Sullivan

That probably it, indeed. And then this is the article where you say that you'd like to move out in the desert somewhere far away from manmade disturbances.

Reber

This is 1942?

Sullivan

Right. I guess the question is, why didn't you move out there?

Reber

Well, the War came on in '41, probably about the time or a little after the time this was written. When did this appear?

Sullivan

This was received in August '41 [Sullivan: published in August ’42].

Reber

Let's see, the War hadn't begun yet, at least for us. Damn, it took them a year to get that thing into print.

Sullivan

That was a revised manuscript in May '42, so there was some big delay there.

Reber

Yes.

Sullivan

Was it a referee sort of thing?

Reber

Oh, probably just the War.

Sullivan

Well, why did you have to revise it though?

Reber

Oh, I don't know. I don't even know if it was revised, we'd have to look. I think I've probably got all the revision. I've saved most of that stuff.

Sullivan

I'd really like to go through that sometime with you.

Reber

Well, in any case, see, by this time it was evident that some really good results could be had and I was getting them slowly, and it was also evident that the location I had there was far from optimum with all these manmade difficulties. And it would be a good idea if we had an arrangement where we could look in some direction other than along the meridian, which wasn’t possible there because of the hemmed-in circumstances. And so it seemed as though it would be a good idea to get out of there and get to some place farther away. And to do that, if we're going to do that, then it seemed to be best if I fixed the equipment up with adjustment in azimuth as well as in altitude. By this time I had been working for some time and I had more resources at my command. So I bought some more iron and made up another design, and this blacksmith made up the turntable. This must have been 1941. The turntable was completely assembled in this blacksmith's shop. And then it was all taken apart and stored in the garage at home, because about that time, or a little prior to that, Yerkes Observatory had acquired McDonald Observatory in Texas. I'd been going back and forth to Yerkes from time to time on various subjects and they had a lot of land down there and it seemed as though maybe it would be a good idea if we could get the resources and the time to move the whole shebang down there to MacDonald, because it would be a lower latitude and the climate would be not only better, but we wouldn't have near so much electrical disturbances. And it was near the Observatory itself. If we had some electric disturbances they would probably be coming from the Observatory itself and we'd be able to control them. Most electrical disturbances can be quieted down if you can find out where they are and get control over them. This was impossible where I was there [Sullivan: Wheaton]. So I had made some sort of cursory arrangements with Struve but the War came on and all this stuff stood in storage, couldn't do anything until after the War was over.

Sullivan

So you might really have set up an observatory down there if it hadn't been for the War?

Reber

Well, that was the idea. If the War hadn't come on and we got involved in that mess, I think I could have moved everything down there. And that would have been the logical thing to do. In fact, that would have been a lot better thing to do than me going to the Bureau of Standards which turned out to be pretty much of a mistake. But there wasn't anything offering at that time. There was no National Science Foundation; there were no other resources available. And we might have gotten some money out of who knows, Carnegie or Rockefeller or I don't know. But that's all water over the dam. It was one of those "if" things.

Sullivan

Now, being able to move in azimuth, were you thinking of actually tracking a source?

Reber

Well, no. See, this was 1941, before I discovered the radio waves from the Sun, much less the transients. So there wasn't any incentive that way. But what I was thinking of was trying to speed up this business of taking the data because you wouldn't need near as much receiver stability. In other words revert back to something like Jansky had where we made sweeps around the horizon. And then maybe make another sweep at a higher elevation angle. In other words, instead of taking a year to get a survey we could do the whole thing in a month or less!

Sullivan

So the Earth was really giving you too slow a data rate and you wanted to speed it up.

Reber

That's right. It really was. You could only get one sweep out in a night and if you had bad luck, you had interference or equipment difficulty, that was shot and you had to wait until the next night or a couple of nights later. It was a very slow and laborious thing, especially when you got north of +45°. The polar region beyond Cassiopeia was practically non-existent, that is, the Earth just didn’t turn up there. The sky didn't turn. But if you had an azimuth sweep, that could all be taken care of.

Sullivan

Sure.

Reber

So there was a lot of good possibilities. Well, I've had a lot of good results. You can't expect to hit the nail every time.

Sullivan

Sure, you can't win them all. You mention interference and the automobile ignitions were the worst thing by far, it appears from your traces. Were there other things that bothered you in the neighborhood that you would have liked to have eliminated?

Reber

Well, the main thing was automobiles, but there were some other things. There were some people there that had sparking oil burners. These things would come on at night occasionally, especially in the wintertime. They usually didn't last long because if they were so bad as that, they most likely would fail within a few nights completely and then they'd have to get them fixed. In the daytime there were other kinds of disturbances in the form of women running cake mixers and this kind of thing. And a lot of my records show my electric razor, which I still use.

Sullivan

Really, the same one?

Reber

Oh, yes. It's an old Schick I've had for umpteen years.

Sullivan

Amazing.

Reber

So aside from the automobiles there wasn't a great amount, a few.

Sullivan

You didn't make any efforts to hunt them down or actually put a shield over your neighbor's furnace or anything like that?

Reber

Oh, no. It didn't seem warranted. I didn't have the time or the effort or the incentive. You just put up with them. We did get a few interferences from mobile transmitters on automobiles. At that time most of that mobile stuff was around 30 megacycles or so.

Sullivan

You mean taxi-cabs, that sort of thing?

Reber

Yes, and the police had some. I think it was mainly the police and taxi-cabs. But I didn't get it unless they were pretty close, within a couple of blocks. And what it was harmonic radiation. But that wasn't often enough to be objectionable.

Sullivan

Ok, moving on to your '44 [Sullivan: ApJ] paper, a couple of questions. You had an idea of the Milky Way having structure now and you talk about the various peaks along the Milky Way. And you make the statement that, "The intensity is roughly indicative of the amount of material between us and the edge of the Milky Way. On this basis the various maxima point to the directions of projections from the Milky Way. These projections may be similar to the arms often photographed in other spiral nebulae."

Reber

That was just a guess and a bad one.

Sullivan

Well, no but I'm wondering was your picture that we were somewhat outside of our own Milky Way?

Reber

Probably.

Sullivan

And that there was sort of a disk that we were just outside and that this disk had projections on it?

Reber

Probably.

Sullivan

Ok. Well, that's not a bad guess at all.

Reber

But that was, you see, on the basis that this stuff was due to free-free transition. And it now turns out that the bright spots had nothing to do with free-free transition.

Sullivan

Right, but nevertheless Mills, of course, 10 years later showed that the continuum radiation peaks along spiral arms, the synchrotron radiation as we now call it, so that you can see spiral structure in the continuum, so it's not way off base at all. The only thing that one would say now is that we think ourselves as being inside the Milky Way. That these arms are all around us rather than that we're sort of just outside of it.

Reber

Well, you know here if you look out there in the direction of Perseus, the Milky Way sort of disappears into the background and it's damn difficult to find out just where the Milky Way is towards Perseus.

Sullivan

Yes, it's certainly much weaker than it is towards the center of course.

Reber

So we must be pretty near the edge.

Sullivan

Well, let's put it this way, we're much more near the edge optically than we are in the radio.

Reber

Oh, yes.

Sullivan

Because there's much more hydrogen outside of us relative to the center than there is light and likewise with the radio continuum, I think. I like these plots that you show here, this one taken on Christmas '43, this one is New Year's Day '44, whenever you weren't working, all of these others are taken on Sundays. Ok, now you're trying to explain the discrepancy that the Sun is a strong source but that, "This source must be greatly discounted when explaining the origin of cosmic static. If it were the source," meaning that if the cosmic static came from all the stars, I guess, "If the Milky Way were made of average stars like the Sun, very large area in Sagittarius would have a visible intensity equal to that of the Sun." That would be if you had no dark matter, of course. "Since this is not the case, some other cause must be found to make up the difference of 20 or 30 magnitudes." I'm wondering: is what you mean there that the ratio of optical to radio in the Milky Way is 20 to 30 magnitudes different than the ratio of optical to radio for the Sun? Is that what you mean?

Reber

It's the general idea.

Sullivan

Yes, and that's just about right. I'm making a footnote here: "Reber is saying here that the ratio of radio to optical intensity from the Milky Way is about 1010 times that same ratio for the Sun."

Reber

[Affirmative].

Sullivan

Ok, I just wasn't sure I had that right. Ok, that's about it for this paper, specific questions. Now the 1948 Proceedings of the IRE paper, I don't think I had any specific things there. Now, this review that you wrote with Jesse Greenstein for Observatory [Sullivan: 1947], this is really the first thorough review of radio astronomy and I was just wondering how this came about.

Reber

When was this?

Sullivan

In '47 it was published.

Reber

February '47, I was still in Illinois.

Sullivan

It was probably written in '46.

Reber

Well, I don't know how it came about. I'd had contacts off and on over the years with the people at Yerkes and whether he or I or both of us or somebody else pushed us onto it, I don't know. But it seemed as though that now that the War was over and we had some time to collect our wits and had access to a considerable amount of information, it would be worthwhile to put it together.

Sullivan

Well, it's interesting because this is the first time that an optical and a radio astronomer have gotten together. In other words, it's the first time that radio astronomy is sort of becoming accepted, at least by some optical astronomers. Certainly that there was still a lot of prejudice.

Reber

I didn't realize this. Is this the first time that an optical and radio astronomer had written a joint paper?

Sullivan

Oh, yes.

Reber

Oh, it is?

Sullivan

Yes.

Reber

Remarkable.

Sullivan

And it's also the first time- no, that's not true, because there were your papers in Astrophysical Journal. But this was in Observatory which is, of course, an astronomy journal.

Reber

And now you are going to ask me why we sent it to this bunch, and why we didn't patronize home industry.

Sullivan

Oh, I don't know. I'm not going to ask you...

Reber

That I don't know either.

Sullivan

I wasn't going to ask you that. But you do in here, you talk a little bit about the errors in your measurements, about how reliable they are: "It's improbable that errors as large as a factor of 10 exist, but errors of a factor of 2 are not excluded." I was wondering why didn't you put some similar sort of discussions in the original papers?

Reber

Probably because at that time I hadn't given it any great thought. By this time Greenstein was probably asking me the questions about how reliable were these things.

Sullivan

Right, trying to pin you down.

Reber

And I was trying to give him some, you know, rough-cut idea of what things were.

Sullivan

Ok, now if we just take a look at your engineering articles, here's one in '47 on, "Antenna Focal Devices for Parabolic Mirrors." How does this relate now to what was used in the radio astronomy experiments?

Reber

Well, I needed a broadband antenna and so this was an attempt to find out the impedance parameters of various broadband designs.

Sullivan

Now was this applicable to all of the different frequencies you used?

Reber

Well, this was particularly a development on the feed for 480 megacycles.

Sullivan

On the last one, yes. That's what I thought. And now this '44 article on, "Reflector Efficiency," this was the 160 MHz thing primarily, right?

Reber

[Affirmative].

Sullivan

And how to illuminate the dish and so forth.

Reber

I'd forgotten about this. This was an elaborate thing, wasn't it?

Sullivan

Oh, you had all the equations that are columns long in this paper. And then here's the actual illumination curve that you had and then, "Electromagnetic Horns," in 1939.

Reber

This is some of that microwave stuff.

Sullivan

Did you ever use such horns on your antenna?

Reber

Yes. At 3300 megacycles I used a horn similar to this.

Sullivan

Right, and what about 910, also?

Reber

No, at 910 [Sullivan: MHz] I just used a cylinder. In other words, if you wanted to get the maximum directivity out of the horn on a given aperture and length, you don't do this, and you don't do that, but you build it like that.

Sullivan

Right and you found this out experimentally, basically?

Reber

Yes.

Sullivan

So this was not used for the 480 MHz either, just the 3300?

Reber

That's all. It was sort of an engineering exercise, really. I did have a large horn built by Alcoa for use, I think, 910 megacycles but it was never used because I couldn't get anything. And the idea was to improve the aperture efficiency by cutting down the side lobes. You'd get a bigger opening at the orifice of the horn. But it was never used and it got demolished at the Bureau of Standards and that was the last I ever saw of it.

Sullivan

Yes, I thought that in your early radio astronomy article that you mentioned that you used a horn at 480 MHz.

Reber

No, if I did it was a mistake.

Sullivan

Well, now I'm probably remembering wrong. Let's see if I can find that. No, I don't see it now. I must be remembering wrong, ok.

Reber

It was a fairly large horn. It must have been about 6 feet long and about 2 feet or so in the aperture.

Sullivan

Oh, wow.

Reber

And the idea was to put a small drum at the backend of the horn. 2 feet on the aperture at 900 megacycles, about 30 cm, would give a couple of wavelengths across the aperture which would improve the aperture efficiency.

Sullivan

Right, like you were just showing me here, yes. Here's another article in Communications on, "Electric Resonance Chambers," and this is what you used at both 910 and 160?

Reber

And the original observations at 162. You can tell by looking at the pictures because the early pictures of the big drum show- here, see, small opening. And the antenna is back in here. Then when I got the broadband amplifier, I broad-banned it out by taking this iris off and putting cones in there instead of a wire. Well, that drum and the cones all disappeared.

Sullivan

Now this was a review article in Radio News in 1948.

Reber

The one where I had projections sticking out in the direction of Cassiopeia.

Sullivan

I'm going to reproduce this figure because I think what you were trying to do here was to make the radiation from the Galaxy into an antenna pattern that engineers could sort of understand.

Reber

Apparently so, but that was sure way off, that one.

Sullivan

Well, it a valid way to show the data. It's sort of interesting.

Reber

But you notice under good circumstances it was a darn good signal-to-noise ratio.

Sullivan

Oh, yeah. I mean, there's no doubt, even here there's no doubt that on the lower envelope that you got a good signal there. You wrote this letter to Nature in November '46 and this was after you first picked up solar flares, right?

Reber

[Affirmative]

Sullivan

But now at this time- were you aware of the other solar observations by this time because you did write to Nature? Well, you did give references to the two of them here.

Reber

To Pawsey and Hey, obviously I was aware of them.

Sullivan

Right. Do you remember if that was only after you made the observations and then began to look through the literature?

Reber

I haven’t the faintest idea.

Sullivan

And then here's another short little thing in the Proceedings of the IRE in '47.

Reber

Well, this was after I went to NBS, but it was still all on the Wheaton data. This was all taken at Wheaton. And this is just to show the difference in how the background fluctuates, over very large amounts from day to day, a big difference than a few years previously when I was on 160 megacycles.

Sullivan

Where is Sterling, actually?

Reber

It's about 20 miles or so airline from Washington, across the river over into the back country of Virginia.

Sullivan

Directly west?

Reber

Directly west. It's remarkable how quickly you can get into the deep south when you get over into Virginia.

Sullivan

Yes, I used to live there. I went to the University of Maryland as a graduate student. You’ve more or less said why you wanted to leave Wheaton and that the only opportunity you could to find to continue this sort of research was at NBS.

Reber

That's right.

Sullivan

And you've already commented that your hope was to bring your antenna with you and continue on this same sort of line, but they had other ideas. But can you just sort of summarize what you did do in the couple of years you were at NBS?

Reber

When I got there, it was evident that they weren't interested in radio astronomy. What they were interested in was justifying their own and my existence, which could be done in this roundabout way on ionospheric predictions. And so the program really consisted of doing solar radio observations, particularly looking for the transients and measuring them and their duration and that kind of stuff. And so about that time, this is 1947, they'd lugged in a bunch of stuff from Europe, mainly German stuff. And this was done by the Signal Corps, with the idea of assessing it for its military capabilities. And it was going to be turned into scrap and so we found out about this and we got three of these Würzburg dishes from Red Bank, New Jersey. And they were taken down and I modified them somewhat and tipped them up so that instead of being alt-azimuth mounted, they were polar mounted. And then we built some more electronics equipment and started making routine observations of solar radio waves at several frequencies, I think, 53, 160, and 480 megacycles, using my electronic gear, at least to begin with, although that was later to change. This was done as a routine thing and we collected vast amounts of this information. I don't know what it was ever used for, but we did it.

Sullivan

Well, the only publication is this one in Science in '51 in which you talked about some of the bursts, motion in the solar atmosphere you call it.

Reber

Yeah.

Sullivan

And that's, I think, the only real publication I found on this. Were there internal NBS things, do you know?

Reber

Not much, really. They weren't really interested in this. It was just one of those things they did because they were doing it.

Sullivan

But during this time though, you did go up with Hagen and Haddock...

Reber

That's right.

Sullivan

To Alaska. Maybe you can tell me about that business.

Reber

Well, Hagen's idea was to get some information about the radio corona of the Sun using the Moon to eclipse part of it. This was a good idea and it had more relevance at microwave frequencies that NRL were observing at than at the frequencies we had available. However, they put some equipment at our disposal, so Beck and I went up there and made some observations. And they're shown here, they don't tell you a great deal other than what you already know, that is, the solar corona gets larger as the frequency gets lower and the Moon obscures less and less of it, and when you get down to the shortest wavelength they operated at, 3 cm, the corona is pretty much like the optical corona in size.

Sullivan

Is this Beck the same one as at the Bell Labs?

Reber

This is another Beck. The Bell Labs Beck is A. C. Beck. This is Emanuel A. Beck, a generation different.

Sullivan

How do you view that early NRL effort? I've talked to Mayer and I haven't talked to either Hagen or Haddock yet.

Reber

How do I view it?

Sullivan

Yes, I mean, were you sort of always working closely in contact with each other?

Reber

Oh, more or less. We knew each other and I went over and saw their stuff and they'd come over and see our stuff but we weren't competing; we weren't even doing similar things.

Sullivan

Because you had such different frequencies, basically?

Reber

Yes. I never did find out why they were doing it, that is, they seemed to even have more slender strings to sustain them than we had.

Sullivan

That's always been a problem. It still is today at NRL.

Reber

It seemed to be more an exercise in microwave technology than anything else. And the frequencies they chose made it pretty hopeless to do anything except solar work with that equipment.

Sullivan

And so the idea of you getting involved was mainly for the 65 cm point, I guess?

Reber

Well, see we had some low frequency equipment which they didn't have. And so by inviting us two to go along at 480 megacycles, it gave them 3, 10, 30, what was it?

Sullivan

3, 10 and 65 is plotted here.

Reber

3 cm, 10 cm, and 65 cm. They only had two, I guess. Oh, they had some optical equipment they took along, but it was useless.

Sullivan

No, here's a photocell here.

Reber

So there were three radio frequencies?

Sullivan

[Affirmative].

Reber

At these wavelengths, 3, 10 and 65 cm, and this is their optical equipment, doesn't it show it?

Sullivan

But now here they say 4 radiometers. Oh, 8.5 mm they had also.

Reber

Maybe it didn't work.

Sullivan

Apparently. I'm sure they say in here. "The rain prevented use of this camera and the 8 mm receiver." Not a very beautiful eclipse, eh? Well, let's see, there's a couple of early reviews that you did in Sky & Telescope and Scientific American. I don't think there is anything...

Reber

That Scientific American one, is that the one there?

Sullivan

Yes.

Reber

That's got my name on it but I didn't write it. It doesn’t sound like me.

Sullivan

Oh, because their editor changed it so much, you mean? I've heard that from other people, they've said that about Scientific American too.

Reber

Scientific American takes the bull by the horns and writes its own articles.

Sullivan

Here's a AAAS meeting in Boston, a Symposium on Radio Astronomy.

Reber

That was a Christmastime one.

Sullivan

Right, in which you gave an address.

Reber

I think this was just a sort of synopsis thing, wasn't it?

Sullivan

Yes, it was sort of showing the history of radio astronomy.

Reber

Yes. I think that is probably under Bok's administration. Anyhow, Bok, I think, was one of the promoters of this.

Sullivan

He may well have been.

Reber

And the feeling was that radio astronomy hadn't been given a fair go, i.e., the scientific community at large was mostly unaware of even its existence. And that we should get out and put our best foot forward and get some generalized things to educate these ignoramuses and show that there was something more to science than nuclear physics.

Sullivan

So this was a publicity effort, basically?

Reber

That's what it amounted to. This kind of thing occurred several times.

Sullivan

Is this true, did you actually present this paper? It has it here that Kraus gave it in your absence.

Reber

What does it say?

Sullivan

But then it crossed out.

Reber

"Paper to be presented because of Dr. Reber's absence in Boston by..." I'm pretty sure I was there. I'm sure I was there.

Sullivan

Ok, well, someone had it crossed it out that wasn't me. So apparently that was to correct that. I forget where I got this thing. I do a lot of scrounging.

Reber

I'll tell you a good story on this business of ignorance. I'd gone to the Bureau of Standards, that was '47, and it was probably Spring of '48, and the American Physical Society was holding an annual meeting there, quite a big thing, several hundred people, maybe a couple of thousand. And the promoters at NBS thought NBS ought to get somebody there to put NBS on the program. And what could they find. So they put the button on me and said now, "You've got to go give a paper." I said, "All right, I'll tell them about solar radio waves because that's what we're doing here at NBS." And so they made all the necessary arrangements and got me on the program and so on. I didn't have to do any of that. And the program was printed and in due time I went down there. I didn't attend all the sessions. And I remember this was a very large hall. I don't remember which hall it was but there's two large structures, and one of them is [Sullivan: Department of] Agriculture, I think on the west side of the White House, or was it there? Anyhow, it was a large hall.

Sullivan

The Commerce Department? Because NBS is part of the Commerce Department.

Reber

Well, it doesn't make any difference. It may not have been either one of them. I've been to so many meetings I've forgotten which one it was. It was a very large hall and it must have been about 11:00 in the morning. The sessions had been going for some time. And I got there a little before the previous paper had been finished, five minutes or so. And the previous paper was about some obtuse nuclear physics thing like nuclear cross-sections, and the hall was just jammed with people standing around the back and in the aisle. And a lot of people were smoking pipes and it was a smoke-filled room. Finally, there were a couple of questions, but there wasn't much of any time so the Chairman closed the session and then there was an intermission, five minutes or so. When this speaker quit, practically everybody got up and went out. And they opened the doors and let some of the smoke out. So then I was the first one on the next half of the program, so I got up there and Rabi was chairman. Pretty soon a few people filed back in, but the hall was about a quarter filled. So it was very evident that what the program said was uninteresting to the large majority of the people. So, Rabi got up there and he introduced the speaker and he reads the program. He says, "Our next speaker will be Mr. Grote Reber of the National Bureau of Standards and his subject will be 'Solar Radio Waves'." And then he looks at it and he looks at me, then he looks at the program again and he says, "And Mr. Reber will tell us about solar radio waves and I hope that all right." Then he sits down. Well, it was pretty obvious that Rabi had never heard of solar radio waves and he hadn't even read the program. That was how far radio astronomy had infiltrated into the physics community.

Sullivan

That's a very good example, all right.

Reber

Well, anyhow I gave them a spiel on solar radio waves for 10 or 15 minutes and I guess it was all right. But it tickled me in a way that you think that Rabi would have at least read the program, but he didn't.

Sullivan

When he's the chairman of the session, right.

Reber

And he didn't have the faintest idea what solar radio waves were.

Sullivan

But then you've already told about Compton who was an example of one who did have an open mind.

Reber

Yes, he's very different, very different.

Sullivan

Right, but probably most physicists were more like Rabi.

Reber

Most of them were more like Rabi.

Sullivan

It was just something they were not particularly interested in. Ok, we were talking about your tenure at NBS and so you were measuring the Sun and I imagine you got tired of doing that after a while.

Reber

The reason I left there was, it was one of these political things. We've had some examples of that in Australia just recently. Colorado isn't poverty stricken in the sense that Mississippi is, but it doesn't have much to offer, that is, for instance in all this log-rolling, you got a bunch of guys from Illinois and Iowa who were log-rolling to get subsidies for their corn. And then there's the wheat boys out in Minnesota and the Dakotas and the cotton boys down in the Gulf. And these guys have all got their ax to grind to keep their subsidies and their special privilege functioning. So Colorado didn't have anything like that, that is, they might have a little silver, but nobody much cared anything about that. So the special privilege boys are looking to pick up votes. They want somebody to get behind them and help push for wheat, corn and cotton. And so when Colorado comes around and says now, "What do you offer me?" They haven't got much of anything to offer them, but they'll be glad to give them anything if Colorado will vote for wheat, corn, and cotton. So when it looked like some money was going to become available to build some new laboratories for the Bureau of Standards, then the log-rolling went into the direction of shoving this thing to Colorado. Not because there was any point in sending it out there, but simply because this was something Colorado could get. In other words, Senator Allot and his boys could go around and say, "Now, we want that thing, because if you don't give us that thing we won't vote for your corn, wheat and cotton." The corn, wheat and cotton boys couldn't give a damn less.

So, they decided that the whole thing was going be shoved out there, which it was. I got pretty tired of them at that point because this equipment we had, I had worked on it for several years and done my best to build it up and make it run. And it was old equipment. Some of that stuff, you know was pretty old. I looked at the production dates on those things. The dogma has it that the British invented radar. Well, maybe, but I'm not so damn sure on that, that is, there were 1938 dates on some of that Würzburg equipment. So, in any case, what they wanted to do was to have me pull everything down and lug it out to Colorado. And I couldn't see that. I wasn't dead-set against going out there, but if they got that much money let them buy some new stuff. Scrap all the old stuff and let's go out there and start over and do something new. But to haul all that stuff down, lug it out there, and set it all up again, that like digging ditches to put the dirt in from other ditches. So I just quit.

Sullivan

So what was your next move then?

Reber

I got a subsidy from this Research Corporation. I wanted to try the sea interferometer experiments that Bolton had been doing in Australia.

Sullivan

What year is this now?

Reber

1951.

Sullivan

And you’ve been supported by Research Corporation ever since, haven't you?

Reber

That's right. I looked around a lot. And I was rather impressed with what Bolton had been doing out there in Sydney. And I thought this was a pretty good technique and so I hunted around for some place where you can see a source rising from the sea and setting into the sea. And this seemed like an opportunity so I thought all right, the future doesn't look very bright working for the Bureau of Standards. Why don't I give this a whirl for a few years and see how it goes. And so I went out there and worked in Hawaii for a while. It wasn't very successful. But anyhow, it was different.

Sullivan

What did you actually do in Hawaii?

Reber

Well, I found this volcano called Haleakala meaning in Hawaiian the home of the Sun or a place dedicated to the Sun. And there was an access road to the top, and that was one reason for choosing it. The other main reason for choosing it was from the top of that you could see a sea horizon off the east and around to the north. Well, the island of Hawaii was to the southeast, then you could see all the way around...

Sullivan

Ok, this is continuing with Grote Reber on 25 October ’75. So you had a broad horizon?

Reber

Well, pretty much around the horizon. I remember Oahu was just on the horizon slightly north of west. So it gave an opportunity for trying this interferometry thing on a great scale. And I did get some results, but not very good results.

Sullivan

Why did you think the sea interferometer was more promising than the Michelson interferometer that Ryle was developing?

Reber

It was the best possibility in principle anyhow of being the variable space interferometer. When the source is right on the horizon the spacing simply would be zero. And as the source rises, then the spacing between the real antenna and image antenna under the sea rises at twice the height of the mountains, in this case would be a maximum of 6 km. So I had the possibility of an interferometer where the spacing changed from zero to 6 km in about a half an hour or thereabouts. So we would get patterns that started out very slow and increased in speed and got to be very fast. And at some place, if the source had finite size within its limits, the pattern would disappear. This would tell you something about the size of the source. Similarly, if there was a pair of sources, you get pairs of patterns and these would beat. And then you'd get a compound pattern. And furthermore, since it rose from the sea at a different angle than it set into the sea, you'd get ideas about the cross-section of this source in two different directions.

Sullivan

Right and you could do all this with a single antenna?

Reber

Yes. And it did work after a fashion, that is, I could measure the strong sources, Cassiopeia and Cygnus. I was able to demonstrate Cygnus was a double in one direction but single in the other direction. And there were a few other sources. I measured Taurus and bumped into Jupiter, a few things like that. But for the effort involved and the difficulty in doing the observations it wasn't warranted.

Sullivan

You had this short article in Nature in '55 and you say that the, "details of these studies will be described elsewhere." I don't think there ever was a detailed paper.

Reber

About what?

Sullivan

About the Hawaiian observations, was there?

Reber

Oh, yes. There was an elaborate paper that appeared in the Geophysical Journal.

Sullivan

Oh, that's right, I haven't gotten that one yet, in '58 or '59, something like that [Sullivan: Journal of Geophysical Research, 1959]?

Reber

Something like that. It gives all the calculations about positions and the curvature of the Earth and everything else. It turned out to be a difficult kind of thing to do because I neglected this business of manmade interference, which was bad enough back in Illinois. But you see, here you were up on this tremendously high mountain, 3 km high, looking out unobstructedly all over. And consequently I was getting interference from great distance, that is, for instance they had a pineapple cannery and they had a place where they made the tins and they had spot welders. This was maybe 15 miles away and that stuff, when they ran, just roared in there, and I could even encounter radio interference from Oahu, Honolulu, about maybe 90 miles away. Well, it was a direct line. And so you were in a very exposed position, just exactly what you didn't want. What you need, of course, is a hollow place surrounded by hills. So from this point of view it was a poor thing.

Sullivan

But you had to go there to get the long baseline, to get high?

Reber

That's right.

Sullivan

Which years then were you working up in Hawaii?

Reber

About 1951 to 1954, about three years out there. I took one year to get it going. I must have made observations in '52, '53, and '54, something like that.

Sullivan

This was all supported by Research Corporation?

Reber

Yeah.

Sullivan

And then what was your next move?

Reber

Well, then I cast about for something else to do. I wasn't part of any institution or part of any organization where I had to report to anybody and be on any given premises at any given time.

Sullivan

I gather that's not your style.

Reber

Yes. Well, so you might say I was foot-loose and fancy free in the sense that I wasn't committed to making observations out there at Boulder, Colorado for the rest of my life, or something like that. And so if I decided in my own mind that if it wasn't worth spending more time, money, and effort on this Haleakala experiment, I could scrap the thing. We hadn't spent an awful lot of time and money on it. I’d extracted out of it what I could, which wasn't very much. And I thought well, why fuss around with this at all anymore? Why not try something entirely different? And I think I told you I had already made investigations as to where the ionosphere had the lowest electron density.

Sullivan

Right, but could you just briefly repeat that because we weren’t taping then?

Reber

Yes. I thought all right, now is the time to give that thing a whirl. You see, here it was '54, well this is in the solar activity minimum. And this would be an auspicious time. I was a little late actually. And I had made contacts down there in Australia and found out this circumstance where there were poles, wires, and a hut, and power, telephone, and water. So I quickly hashed up some electronic gear for around 2 megacycles and took it down there.

Sullivan

Right, but before you go further though can we just get the story of when you went and plotted up the NBS data? I didn't get that on tape before. Was that while you were in Hawaii, that you went to Washington, D.C.?

Reber

No. I’ve sort of forgotten the details. It was NBS data and I think I looked at a lot of that while I was still in Washington. But NBS also had an ionosphere station on Maui, the same island I was on. And undoubtedly yes, I did. I spent a lot of time there looking over their stuff. But this wasn't a thing that was done in a few weeks. This was done in patches over a period of several years, you might say, while I sort of collected my ideas. And I think the graphs I told you about, the maps were plotted while I was in Hawaii.

Sullivan

These were maps of the maximum usable frequency?

Reber

Maps of the minimum critical frequencies.

Sullivan

Well, the critical frequency of the ionosphere?

Reber

The critical frequency of the ionosphere.

Sullivan

As a function of position on the Earth?

Reber

As a function of position of the Earth for different seasons of the year, summer, winter and equinoxes. There were contours: inside a given contour, the critical frequency dropped to some level or less. And these contours turned out to be in the northern hemisphere rather long streaks that were arcs starting up at Prince Rupert, British Columbia and going down through Winnipeg toward Duluth and across Lake Superior in the direction of Toronto and then back north again up beyond Quebec and St. John's. At the time I didn't really hardly believe these. I thought that they were a peculiar set of contours induced by some peculiarity, the way the data was taken or the location of the observers, or what have you. It was not a real demonstration of what actually happened in the ionosphere. But, in fact, it was, because in the late ‘60s, the Canadians put up a few Alouette ionosondes and they plotted their contours and lo and behold they were the same thing.

Sullivan

Really, amazing.

Reber

Or very close.

Sullivan

What causes this streak? Are there any ideas what causes it?

Reber

Well, no, not really. It seems to be a combination of effects which has something to do with the fact that the magnetic axis of the Earth is not coincident with the rotational axis of the Earth and that these particular regions are shielded from the particles that fall in by this geometric combination.

Sullivan

I see.

Reber

Because it doesn't appear again over in Siberia. It's strictly on the side where the magnetic axis is displaced as far as possible from the polar axis.

Sullivan

And so you get less ionization in that part of it?

Reber

That's right. And a similar thing occurred in the southern hemisphere, although there are not enough stations and there's so much water out there that you can't delineate it in that detailed a fashion.

Sullivan

So there is a similar streak in the southern hemisphere?

Reber

Apparently. Yes, there probably is, but I've never seen it drawn by anybody. The Alouette people haven't done or reduced their data in that fashion. Anyhow...

Sullivan

Well, you found another hole in Tasmania?

Reber

Yes. That's right, in the southern hemisphere, and it seemed to be on the basis of the rather more limited data available, a deeper hole. That is the electron density dropped lower, meaning the critical frequencies got lower. So I decided to go down there, partly on the basis of adventure, partly on the basis that the southern sky looked more interesting with the center of the Milky Way and the Magellanic Clouds and one thing and another overhead, partly due to the practical proposition that I was offered the facilities of these poles and wires and huts and things. So I went down there.

Sullivan

Was this hole in Tasmania known about before you plotted this stuff?

Reber

Well, no. I got a lot of advice from the pundits that I was wasting my time. I forget all the reasons why it wasn't any good, but in essence, oh, I think one of the reasons proposed that it wouldn't work was that there would be a lot of absorption in the ionosphere. And another reasons proposed was that I'd get a lot of radio interference from manmade stations. And even if I could find a clear channel, I'd probably get drowned out by atmospherics and I don't know what all. But when you started to question these people on the base for their pessimism, they really didn't have anything. But there’s a philosophical point here. That is, if these people thought it was any good, they'd be doing it. So when you go out and you get this kind of reaction, it's to be expected. They're interested in the things they are interested in, whatever they are. And they think those things are good, therefore they're doing them. So you come and suggest something else, and they haven't given it any thought and off-hand it very different from anything they have ever thought of and it can't be any good because if it was any good they'd...

Sullivan

They'd already be doing it.

Reber

Exactly.

Sullivan

That's a good point.

Reber

Well, in any case, what happened was...

Sullivan

When did you go down to Tasmania, actually?

Reber

I got down there on the first of November, 1954. Well, I arrived in Sydney then, but I didn't get to Tasmania until some weeks later. That's summertime. And I got my equipment all organized and going by February or so, which is still summertime. But I remember we tried it out until along in March, which was autumn, and it was rather cumbersome. I had one of these high-speed recorders and the idea was- see, I had listened to all of the pundits and so I'd naturally gotten influenced by them. And the idea was that by having a high-speed recorder, the pen would come back quickly with a short integration time and thereby arrive at the background level in between the surges of atmospherics. And this is true when there are atmospherics around. But it's not true under the observing conditions, because there aren't any atmospherics. We set the thing up and during the day had tuned it to some frequency about 2200 kilocycles, and then went away and let it run and then came back in about three days and looked to see what I'd caught. And lo and behold on the very first night the ionospheric hole had opened up and I got a beautiful trace without any atmospherics or interference or anything. And the succeeding two nights weren't as good because the electron density didn't drop back far. But then as winter came on, I got a long series of traces. What happens is that when the electron density really does such that the critical frequency is below the observing frequency, then there is sensibly no absorption. And since there is no absorption, there is no reflectivity in the ionosphere either. And so all the manmade stuff and atmospherics disappears out in space, it doesn't come back. It's got a void out there. And all the stuff that would be bouncing back and dribbling in...

Sullivan

It has to come directly to you, that's the only way it can get there?

Reber

Yes. And also it turned out that the cosmic static intensity at those frequencies is very high and so it drowns out anything else. So when the observing conditions are good to get suitable data, then they're so good that you aren't bothered by any terrestrial stuff. There's an in-between situation, that is, you can have the daytime situation where the ionosphere is absolutely opaque and then the D-region goes away and you still have critical frequencies which are much too high. And then the critical frequency drops gradually, particularly in the evening, it doesn't do it uniformly and slowly, apparently the ionosphere breaks up into blobs gradually and these things gradually dissipate. So there's a transition region from anywhere of a half an hour to several hours. And during this period the cosmic static leaks through and the pen is going up and down gradually, anywhere from a period of a minute or less to a period of several minutes or half an hour. Well, these are not useful data. But then once the hole really opens and becomes transparent, and the hole is big enough to encompass the entire antenna beam, it draws absolute straight beautiful traces. The signal-to-noise ratio is as good as any of those. There's nothing in there of the atmospherics.

Sullivan

Very interesting.

Reber

And so when the circumstances were good, they're very good.

Sullivan

When the signal comes, the noise goes away, very interesting.

Reber

Right.

Sullivan

But I haven't asked you, what was your motivation to go to these very low frequencies? What made you think of them?

Reber

I never did know much about this microwave stuff, and furthermore it seemed to be in good hands, that is, these fellows that were doing it seemed to know what they were doing. They've got resources far beyond anything I have. And there's no sense to me to try and compete with them. That's silly. They're all knocking themselves out competing with each other. Why not use your wits, if you've got any, and do something different. And here was a situation which seemed to be worth exploring. I’d gotten all this pessimistic advice and maybe because they really didn't know anything. These people who were giving me this pessimistic advice were merely telling me they don't know. And there wasn't anybody that knew.

Sullivan

And they hadn't even bothered to try to know, either.

Reber

So how could I lose? Again, I was in a situation just like in Illinois, i.e., all I had to do was do something new and different and keep my eyes open and see what happens.

Sullivan

But I gather also that you had made the decision that your style was to work alone and that you weren't going to join them? By this time there were groups that you could have joined, undoubtedly.

Reber

Oh, I could have, sure.

Sullivan

But that you just liked to work by yourself.

Reber

Well, yes. Supposing I joined a group, I had two choices. Either I worked with them on what they were doing and participating in it to the extent that I could, or I engaged myself in a lot of arguments with them about trying to do something different. There was no point to that.

Sullivan

Yes, why not just do it yourself.

Reber

If I was going to do something different, I might as well do it on my own instead of engaging in a lot of arguments.

Sullivan

Right. The only possible advantage would be that you could get more funding if you were part of an institution.

Reber

Perhaps. I never was really short of money, that is, I could have spent more perhaps, but the mere spending of a lot of money doesn't necessarily mean that you'll get any results.

Sullivan

No, that's certainly true. Where does Ellis fit in here?

Reber

He's the one that invited me down there, really. He was a graduate student at the University of Tasmania and he supported himself. He was running the ionosphere station for the ionosphere prediction service with the Australian government. And I don’t remember how I got in contact with him. It may have been through some paper he wrote in one of the journals. I guess that was it, because he had been writing papers on the ionosphere. In fact, I think some facet of that that he used for his thesis at the university. Anyhow, it was through him that I learned that they had moved their ionosonde from one place to another, and that the old station was open. So I went down there and he thought it was a good thing, so he joined up with me and we did these together. And he's been working at more or less ever since.

Sullivan

Ellis has?

Reber

Right.

Sullivan

And, well, you have too in one form or another.

Reber

Yeah.

Sullivan

What do you think in your opinion are the primary results that have come out of this low frequency research?

Reber

The intensity of the stuff continues to rise as low as the frequencies we’re able to measure. The absorption due to ionized hydrogen in the Milky Way begins to show at even 20 megacycles in Shain’s results, not greatly, but it's there. Ellis' results at frequencies down to around 5 megacycles show it more pronounced. And at 2 megacycles it was even much more pronounced. This is not surprising. However, at 20 megacycles Shain's results show that there is still a long and complex bright continuum spread along the Milky Way and that at higher galactic latitude it gets fainter and fainter. But at lower frequencies this phenomenon is still present, but not so pronounced. When you get down to 2 megacycles, the situation becomes more extreme. It turns out that at 2 megacycles the background is not bright along the Milky Way, the background is brightest at high galactic latitudes. And you have strung along the Milky Way a series of deep absorption ridges. So at 1 megacycle the situation should become even more extreme, that is, the bright region should contract to some very bright small area around the galactic pole. And probably the absorption regions along the Milky Way will coalesce into a rather large band getting even darker and wider. And if integrated over the whole sky you'd probably find that the total integrated intensity would drop because of the large amount of absorption. So, limiting the discussion to the 2 megacycles which we have data on, it's very evident that there is some very bright region outside the Milky Way that's producing these celestial radio waves and that they are being absorbed by the ionized hydrogen within the Milky Way.

Sullivan

When you say outside, might that include a halo of the Milky Way or do you mean truly extragalactic?

Reber

Well, it's certainly large compared to the Milky Way, but not twice as large, maybe 20 times as large. It may be connected with the Milky Way, perhaps. Although the absorption is so complex and so great that you cannot identify this bright region as having a structure associated with the Milky Way.

Sullivan

But how is it that you get a handle on this size? Is this the paper here, the '68 paper?

Reber

The '68 paper, yeah. You see, this is the brightest region in here [Sullivan: 3 MHz observations of mid ‘1960s], but there's one little bright streak around here that's not up much. These are in dBs. I can't read that, I think that's 22, 21, 20. And this is Centaurus here, and this is the deepest, darkest patch right on zero degrees longitude and latitude. Then there are these two more or less equal dark patches on each side. I think this is the thing associated with the Gum Nebula, or is it that one? I can't remember which one. There's another little patch up in here. But in any case, if there's any structure to this bright region, it's very large compared to the Milky Way.

Sullivan

Because the bright regions extend to all latitudes?

Reber

Seemingly so.

Sullivan

Is that the reason then?

Reber

That is, if the bright structure were...

Sullivan

If it were just local, then you wouldn't see the absorption here, then so it has to be somewhat larger than the Milky Way.

Reber

But it’s got to be a lot larger than the Milky Way, that is, for instance, if this is the visible Milky Way and we're out here somewhere...

[Break]

Sullivan

Right, you were saying about Jansky's antenna reconstruction.

Reber

Yes. I was there at Green Bank, rehabilitating my antenna in 1960. And this was to be on the left-hand side of the front entrance to the NRAO Observatory. And so I thought it would be nice if a reproduction of Jansky's antenna was erected on the right-hand side of the front entrance. It would be suitable and appropriate. And so nobody there seemed to be interested, but I wrote to Southworth who was retired from Bell Labs, and suggested the project to him, and that if he thought it was a suitable type of project he would know the proper people at Bell Labs to take the matter up with, which he did. And he got a positive response, saying that he had contacted the Laboratory and that they had decided that this would be a fine thing and furthermore they had investigated the matter and they were able to locate all the drawings from which the original antenna was made and furthermore by good fortune the man was still on their staff who had built Jansky's original antenna.

But he was going to retire pretty soon. And that they had made a pretty thorough search and the only thing they could find left from Jansky's original antenna was the speed reducer. And that they were willing to undertake the reconstruction of this according to the original drawings, just the way Jansky had it. But they were handicapped by the fact that they didn't have any more hardware except the speed reducer and that it was imperative to find some wheels and axles from Model-T Ford cars and that there weren't any available at this late date in automotive junkyards. And did I have any suggestions? Yes, I did have a suggestion. That I was out there in the boondocks in West Virginia, and that I would put an ad in the local Marlinton paper, which I did a number of times, to find out if there was anybody in the farming community around there that had any old Model-T Ford cars laying around. And I was able to locate a suitable number of Ford Model-T front axles and wheels, which required a minimum amount of work to repair, which I did get. And we also by good fortune found that we could get the tires and tubes. I think these were 21 inch wheels with 4-40 tires. These tires and wheels were being manufactured today and sold through Sears and Roebuck, because they were a popular item with these antique car addicts. So I collected the wheels and the axles, and they bought the tires and tubes and all the rest of the gear and manufactured the whole thing. And it was brought down there and put together after I left. So I helped organize the reproduction.

Sullivan

I see, you chipped into that but it was actually the carpenter that worked on it, that supervised the reconstruction?

Reber

Yes. At least from what I understand. The same carpenter that built the thing. And he wanted to make changes in it to make it better and they wouldn't let him. They wanted it the way was originally.

Sullivan

As an historian, I’m glad of that. Well, thank you very much.

Reber

All right. I’m getting sort of worn out.

Sullivan

That ends the interview with Grote Reber on 25 October 1975.

Citation

Papers of Woodruff T. Sullivan III, “Interview with Grote Reber on 25 October 1975,” NRAO Archives, accessed January 17, 2021, https://www.nrao.edu/archives/items/show/15140.