We continue with the conclusion of our retrospective look at the Amelia Earhart Electra’s radio capabilities via interviews of radio expert Joseph Gurr by Fred Goerner as compiled by researcher Cam Warren and appearing in the February 1999 issue of the Amelia Earhart Society Newsletters.  

Fred: “[Are} 9.3, 15.45, and 21.7 mc that you referred to back in 1937 as being the ranges or the capabilities of that Bendix direction finder that was in the aircraft [considered] pretty high frequencies?”

Gurr: “Oh boy, I tell you it was.  Initially those frequencies were not used too much.  Today, they are commonplace.”

Fred: “Where would 7500 [i.e. 7.5 mc] fit in there?”

Fred Noonan, circa mid-1930s, in his Pan Am uniform. In March 1935 he was the navigator on the first Pan Am Sikorsky S-42 clipper at San Francisco Bay in California.  The following month he navigated the historic round-trip China Clipper flight between San Francisco, California and Honolulu, Hawaii piloted by Ed Musick (who was featured on the cover of Time magazine that year).  “I don’t care what kind of equipment she had in that airplane,” Joseph Gurr told Fred Goerner, “She did not know how to use it.  Noonan, hell, he didn’t know nothing as far as I’m concerned!”

Gurr: “Oh, that would be wonderful.  That is one of the real good ones.  That is what you call the 40 meter band.  It is a real good general band.  Day time, up to a thousand miles generally with relatively low power.  At night, you can whip around the world.  Again, it is subject to a certain amount of skip.”

Fred: “[Was] Amelia capable of sending CW [Morse Code], or was Noonan capable of CW?”

Gurr: “I don’t know about Noonan but I don’t think Amelia was.”

Fred: “That is why she never made any attempt to use it?”

Gurr: “I was really concerned.  In using the radio direction finder; that is if you are homing in . . . if [you] haven’t got a range and you want to work a problem, you have to know at least an “a” from a “n.”  I’m sure she didn’t know the code.  As far as Noonan is concerned, I don’t know.”

Fred: “Unless Noonan was in the cockpit, he couldn’t have worked any radio anyway, could he?”

Gurr: “No.  The way the thing was set up, we had a key — oh, about that key.  Now, let me see if I can think about that once.  We had a key installed on the navigator’s table in the back.  It was installed when I got into the picture.  The idea was that you would send code.  Code gets out far more distance.  That was great, but then, I have a very hazy recollection that that key was removed.  I don’t remember just when, but some place along the line, I heard that they had removed it.  It might have been in Florida.  Nobody knew the code anyway.”

Fred: “Manning did. It was there to begin with and I suppose it was there for him to use. Neither Amelia or Noonan knew how to use it then?”

Gurr: “That was it then.”

Fred: “It was of no use to them anyway.  They were going to depend upon their 3105 or 6210 channels, and their direction finder.”

[End of radio remarks. The balance of this interview discusses various people such as Vidal, Miller, Pearson, et al.]

[PART TWO: Interview recorded Aug. 14, 1987]

Gurr generally concurred with his earlier story.  He reiterated his fondness for the [direction finder] that “the Navy sent out,” again remarking that “the receiver was an all-band job” that “they can even listen to ham radio on this one.”  (Later in this interview he enlarged on the statement, saying “it went from 200 to somewhere around 15,000 kc because it also covered the 20 meter amateur band, which is 14,000.”)  (If he recalled correctly, this would likely indicate the [Bendix] receiver covered five bands, as did the RA-1B.)

Gurr felt the equipment was fine, but had reservations about the operators.  “I don’t care what kind of equipment she had in that airplane, she did not know how to use it.  Noonan, hell, he didn’t know nothing as far as I’m concerned!” Gurr told Amelia that she didn’t have much transmitting power, but to use 6210 during the day, 3105 at night, and “just press the button. Just say, ’Itasca, this is me!’  Just press the button and Itasca would get a bearing — assuming that the Itasca had the equipment and that they knew how to use it far better than Amelia Earhart.  That was the answer to the whole thing — they would give you a compass heading to take, and you’ve got it made.”

Amelia Earhart with Harry Manning (center) and Fred Noonan, in Hawaii just before the Luke Field crash that sent Manning back to England and left Noonan as the sole navigator for the world flight.

Harry Manning had Gurr’s full admiration: “He was good. He was a nice guy personally, but on top of that he was qualified.  If he wasn’t, he wouldn’t be captain of a big ship like that [the SS America].  He was really good.  I thought, [Amelia] you’ve got it made.  I hate to go on record to say this, but when Noonan showed up — aw, golly!”

“I don’t know but there was just something that happened to all of us [in Burbank] — to
everybody around there, all the people that were working around on the airplane.  Like, if I may say this, the reputation he [Noonan] gave Amelia, and that caused her to take him, was that he was the original navigator for the original trip of Pan American to fly over the Pacific and so on.  Well, I immediately said, ’O.K., so how come he is out of a job now?’  In those days, we were using navigators.  United [Airlines] was using navigators on their trips to Honolulu.  In fact, we don’t anymore, but in those days that is how it was done. Navigators were — heck he could get a job anytime; I’m sure he could.  Something happened fight there.  I never talked to Amelia.  I never talked to Noonan.  His reputation as a man who imbibed a little once in awhile came with him.”

Earlier, Goerner had asked Gurr that, considering the radio installation, if it would have been possible to use the transmitter if the plane was afloat in the pacific.  Gurr said he knew the plane wouldn’t sink for awhile “if they could somehow dump those big motors.”  But the transmitter would operate “especially for a little while.  They couldn’t do it for long because now your engines are stopped and you are running on storage batteries.  It takes power.  Now let us say, under some conditions, if she was able
to land that airplane so that it was floating, even for 5 or 10 minutes, yes, she could transmit because the antenna was in the clear and the transmitter was not in the water because it was up pretty high.  You know, above the navigator’s table.  Now this is all an assumption.  If the airplane was floating at all, yes, she could transmit.  She could really get on that mike button and really transmit.”

Amelia Earhart at the controls of her Lockheed 10E Electra before taking off from New Guinea, on July 2, 1937. She disappeared the next day. (National Archives)

Fred: “How severe would the drain be on those batteries if she were trying to transmit on 3105 or 6210?”

Gurr: “Not severe. It was not that big a transmitter. They were 12 volt batteries, and I would say, [the transmitter would draw] probably 10 amperes when she pressed the button.  Ten amperes would be about right.  I never measured it.”

Fred: “So you would have what? In terms of amount of time available from those batteries.”

Gurr: “Oh, she could transmit for an hour off and on.  But, if that airplane was afloat, it wouldn’t be afloat for long.  It wouldn’t be afloat any three days; those engines would pull them under.”  And further, “I can conjecture what could happen to Amelia’s airplane.  I knew the airplane, all those big tanks, the heavy motors and the skill.  Not only that, I know the Pacific Ocean.  A lot of people seem to think that it is a big flat pond.  It isn’t.  It’s always rough out there.  And you take waves 5 or 6 feet high with little white caps and you try to land an airplane in that, and believe me boy, you just hop, skip, and so on and finally you just plunk!  If you did a good job with your gear up.”

End of “What Radios Did She Really Have?”

We continue today with Part II “What Radios Did She Really Have?” our retrospective look at the Amelia Earhart Electra’s radio capabilities via interviews of radio expert Joseph Gurr by Fred Goerner as compiled by researcher Cam Warren.

In answer to Fred’s query as to how Amelia got this “Navy gear.”  Gurr replied: “I asked no questions.”  Fred showed him several photos of the plane “passed by Navy censors.”  They clearly showed the topside antenna mast and the loop, “and some of the gear below.”  Gurr confirmed that this showed the configuration after the rebuild.

Fred: “Right after the disappearance, newspaper accounts ’mentioned a Joseph Gurr, Burbank engineer, who installed the sending apparatus.’ Then [the story] quoted you as having said: ’9.3, 15.5 and 21.7 mc.’  What does that mean to you?”

Gurr: “She could receive [those] frequencies on the Bendix gear, but not transmit on [them].”

Fred: “To get a heading from the Bendix Direction Finder?  She would receive on those frequencies?”

Gurr agreed, saying: “This was high frequency.  It also had the [2-400 kc band]. [I’m afraid I didn’t stress to Earhart] the value and usefulness and that gear.  Oh, it was wonderful!”

The Bendix RA-1B, used in Amelia Earhart’s Electra during her final flight without apparent success, was a brand-new product and was reputed to be pushing the state of the art in aircraft receiver design.

Fred asked if Gurr thought Fred and Amelia knew how to operate it property.  The reply was only a grunt.

[There following a discussion of the gasoline load, then the subject returns to radio].

Fred: “Why was it do you suppose that Amelia never broadcast on 500 kc? All during the flight on which she disappeared, she never once broadcast on 500 kc.  The Itasca had a 500 direction finder.  The Navy had sent a 3105 direction finder down from Pearl Harbor and installed it at Howland Island.  She kept broadcasting on 3105 and asked the Itasca to take a direction on her on 3105. The Itasca kept asking her to broadcast on 500 and she never did on 500.  Why not?”

Gurr: “There might be a number of reasons for that.  At 500, I never was able to work anybody on 500 when I was working on the equipment.  That was only here locally.  500 kc is a very, very low frequency and you have to have power to get out at all.  [She had] her little 50-watt transmitter and a reduced size antenna.  On 500 kc you want to have a proper antenna.   On sea-going ships, they have these great big antennas between the masts that are separated by quite a distance and they have a lot of wire out there.  That is what you have to have.  On an airplane where she did not have much of an antenna, her range on 500 kc was very short.  If she was, let’s say in sight of a ship, she could talk.  As I recall, we talked about that very thing.  If she was in an overcast and she raised a ship, she could be sure the ship was not very far away.  In reading your book, I think you explained it very well.  She did not stay on the air long enough for the Itasca to take a beating on her.  In those days we didn’t have the automatic features.  We had to do all of this manually.  The radio operator on the Itasca would tune the signal in, then he had to rotate his beam to get a null and I don’t think she ever talked long enough for him to do that.  They kept asking her to send ’A’s.  All they needed was that carrier.”

Fred: “She asked the Itasca to send ’A’s on 7500.”

Gurr: “That means she was using that Bendix machinery.  On 7500 she could have heard that if the Itasca had any power at all, even 2[00] or 300 watts.  They could transmit a good signal for several hundred miles.”

Fred: “At one point, she said, ’we are receiving your signals but cannot get a minimum.’  What did that mean?“

Gurr: “That means she was turning the loop and could not get a null.”

Fred: “Because of what? The signal was too weak?”

Amelia, with Bendix Corporation rep Cyril Remmlein, and the infamous direction finding loop that replaced Fred Hooven’s “radio compass” or “automatic direction finder.”  Hooven was convinced that the change was responsible for Amelia’s failure to find Howland Island, and ultimately, for her tragic death on Saipan.  Whether the loop itself failed the doomed fliers during their final flight remains uncertain.  See p. 56 Truth at Last for more.  (Photo courtesy Albert Bresnik, taken from Laurance Safford’s Earhart’s Flight Into Yesterday.)

Gurr: “There are many reasons she could not get a null.  As an example, unless you have a considerable number, a quite strong signal, nulls are not easy to find.  If the signal is weak, you can go through a null.  You have to have a solid signal.  Then too, in those days the equipment wasn’t developed like it is these days.  State of the Art is quite different.

“In those days, a little static — maybe she was excited, flying the airplane and trying to tune the set to get the best signal.  She might have had the loop turned more or less at the null.  She should have had it straight forward, if she was headed toward Howland.  Had the loop fore and aft to get the maximum signal.  She had a sensing antenna which was that V-antenna and the idea was to first tune in the signal on that antenna and then switch it over to the loop and get a bearing.”

Fred: “This takes time.”

Gurr: “And it takes a certain amount of cool-headedness about that time.”

Fred: “The trailing antenna had been removed at that time?”

Gurr: “It was still on board.  She did not use it on 500 kc.  That was the object of the antenna on top.  We put on all the wire we could, as much wire up there as possible, and to get it off the fuselage so that the fuselage would not have an absorbing or a reflecting effect.  We were very successful.  Actually she had as much wire as possible on that airplane.  This was for transmitting.  For receiving, you didn’t have to have that much.  She had that V-antenna down there which was fine.”

Fred:  “Apparently that was working very well because she checked back in with Lae, New Guinea 800 miles out on 6210 in the daytime.”

Fred: “There were messages that amateur radio operators said they had received after the time of the disappearance of the plane. They were received along the Pacific Coast.  I have talked to a number of the operators and I believe they actually did receive messages. Would it have been possible to broadcast if they had been down in the water?”

Gurr: “Yes.  The antenna was dear.  If that airplane was floating, the antenna was up on top of the fuselage and she could transmit until that antenna was submerged.”

Fred: “Did she have batteries in the cockpit or something that would enable her to power her gear.”

Gurr: “Storage batteries, yeah. There was a storage battery generator. In flight, the generator was charging the batteries. In those days, airplanes carried decent flight batteries. I don’t remember how many she had, but I know she had at least one.  Flying along as she was, that battery was probably well charged.  Then, supposing she was down in the water, and got on the air to transmit, she had the power.  The transmitter itself did not take an awful lot of juice.  It was a low powered transmitter.  She could probably transmit for 30 minutes if the battery was fully charged.  Intermittent, maybe longer than that.”

Fred: “Could 3105 be received on the Pacific Coast and not be received in the general area of where she went down?”

West Coast amateur radio operators Walter McMenamy (left) and Carl Pierson, circa 1937, claimed they heard radio signals sent by Amelia Earhart, including two SOS calls followed by Earhart’s KHAQQ call letters.

Gurr: “Oh yes.  Especially at night. 3105 at night.  It was daytime between here and Howland Island.  It is very unlikely, but at night, yes.  These frequencies are subject to a certain amount of skip and the higher frequency you go, the more that skip.”

Fred: “And not be received by a vessel in the general area?”

Gurr: “That’s right.”

Fred: “This Navy direction finder, the 3105 that the Navy Dept. sent down on board Itasca to use in conjunction with the flight evidently was a rather hush-hush model at that time.  They were experimenting with high frequencies, through a department and the Navy known as OP-G20, which was Naval Intelligence Communications.  You know anything about development of high frequency direction finders at that time?”

Gurr: “Only things that were published.  I had no connection with the Navy or any military organization so far as any of the classified developments.  We knew in the airline business and especially being interested in radio as I was then, I knew pretty well what developments were upcoming.  We knew the limitations of the low frequencies.  We knew that we had to have something better.  Obviously the experimentation had to go to the high frequencies.  At that time there was a feeling that the high frequencies had a tendency to bend, the waves would bend and would get a false radio direction finding.  Maybe that was true in certain locations, certain altitudes and so on.  This was all subject to experimentation.  That was brand new stuff in those days. Now, as you know and we know, the military is always researching, developing and working on projects.  Now-a-days, they call it classified, or secret.  You never stop.

“Obviously the Navy had classified gear then.  And they have it now.  The 3105 [kc] radio
direction finder was considered a pretty high frequency to get a reliable direction, at that time. Today, we know its limitations.  We know what it is doing.  The airlines now have fully automatic units that lock on to the beam and take it right down the line.  In those days, we thought 3105 was getting into rather high frequency.”

(End of Part II.)