TIGHAR

Amelia Earhart Search Forum => Radio Reflections => Topic started by: dave burrell on September 14, 2012, 06:19:38 AM

Title: Post loss Transmissions. Solved?
Post by: dave burrell on September 14, 2012, 06:19:38 AM
No doubt this may create controversy, however after much research, I find there are several key issues with the Brandenburg RDF analysis.

1. The reports starts with the vital(and wrong) assumption that Howland was unoccupied. In fact the Brandenburg report states categorically
" Howland is unoccupied except for the shore party involved in the search"
The report also states that "there were no sources of radio transmission south of Howland to account for the post loss transmissions"

These were two key, (and flawed) assumptions that throw into question the validity of the entire report results.
It is well known, or should have been known, that Baker, Howland, and Jarvis islands were almost continually occupied from 1935 to 1942 with high school students and their sponsor from the Kamhameha Boys school in Hawaii.
The boys went on a 3 month or longer rotation. Then the next group came in. For years this went on.

In fact, Lt Cooper in his journal suggests using the boys to clear the airfield at howland. A crude airfield had already been cleared at Jarvis. The Itasca was not just there for Amelia Earhart. The Itasca had been there, see pictures, for close to two years supplying these colonists and planning an airfield on Jarvis and Howland.
http://tighar.org/Projects/Earhart/Archives/Documents/Cooper_Report/Cooper.html
Here are some of the the original colonists from 1936, though the first groups arrived in 1935.
(http://i262.photobucket.com/albums/ii82/gatorhugger/howlandisland19362.jpg)
Here are ladies lunching on Jarvis island in 1909.
(http://i262.photobucket.com/albums/ii82/gatorhugger/jarvisisland1909lunch.jpg)

Mr.Gillespie in the archives of the US minor outlying islands states there "were no radios for the initial groups of colonists" This is disputed by the day to day diaries kept by the Students and supervisors. They had transmitters almost continually from mid 1935 until finally removed in 1942. And a far cry from "chinese operators" arriving in 1936 for just meterological transmissions and health emergency transmissions, it is highly evident from reading these diaries that the nightly radio shack was the entertainment on the islands. The kids were listening to Hawaiian radio, transmitted to Ham operators, and got updates from the states on family and friends. (keep in mind a lot of "post loss transmissions were at night which just so happens to be after the kids were done fishing,swimming,and had little else to do but write in their diaries or listen to the radio sets).

Please read these diaries for life on an atoll as well, and while food and water was delivered from the atasca, note that 18 gallons of fresh water was collected by the islanders the first week, food was plentiful, and the boys biggest problem was boredom, sharks, and learning to surf.
http://www.jarvisisland.info/panalaau_memoirs.html

This 800 pound gorilla in the room, that there were transmitters, and high school boys on Howland and Baker islands had access to these radios, and in a minor sense Jarvis as well,  for Post loss transmissions is never mentioned. Brandenburg goes into fine detail on radio transmissions reaching the midwest and Florida, it dismisses some transmissions as hoaxes, and screens out other Ham radios in Hawaii, but seems to overlook an island only a few miles from Howland, i.e. BAKER ISLAND, and Howland itself. If he did know radios were on these islands, Why did the report state there were no land radios in the central pacific?  (and please show me one reference where he analyized these transmittors). How can he ignore these radio sets mere miles from his Triangulation theory? And how can his report be valid since he is stating there were no transmittors in the area around Howland?

In summary, isn't it just as likely as Earhart wading to her plane, that a group of high  school boys on Howland or on Baker listening to radio, hearing pleas from Hawaiian radio for Amelia to please just key 4 dashes, might have played at the time what they thought was a harmless joke?
A Bunch of young men saying " hey watch this", grabbing mic, keying it a few times in response to the Hawaiian radio, and setting off a search effort they must have known quickly was a bad mistake. There is no proof of this Hypothesis of course, but the radios were there.

At the very least these radio transmittors should in my opinion be included in the brandenburg report of Post loss transmissions. Those radios should be analyzed to show whether they could account for all "post loss" transmissions.

More information on the colonists for further reading-
http://kapalama.ksbe.edu/archives/historical/huipanalaau/first.php

http://www.oralhistory.hawaii.edu/pages/historical/panalaau.html

http://www.bishopmuseum.org/media/2011/pdf/Hui_Panalaau.pdf

http://www.jarvisisland.info/panalaau_memoirs.html
Title: Re: Post loss Transmissions. Solved?
Post by: Bruce Thomas on September 14, 2012, 07:59:07 AM
No doubt this may create controversy, however after much research, I find there are several key issues with the Brandenburg RDF analysis.

1. The reports starts with the vital(and wrong) assumption that Howell was unoccupied. In fact the Brad(shortened name) report states categorically
" Howell is unoccupied except for the shore party involved in the search"
The Brad report also states that "there were no sources of radio transmission south of Howell to account for the PLT"

These were two key, (and flawed) assumptions that throw into question the validity of the entire report results.

I've quoted the opening words of your post, where you set up your premise with two quotations that I presume come from what you call "the Brandenburg RDF analysis."  At this point, I will only address this portion of your post, because it is where you lay out the premise for the rest of your argument.  You have not provided a link to whatever document from which you purport to have extracted those quoted words.  As an interested reader of your post, I would first like to confirm that those quotes do appear in the document.  You have not provided a link to the document for the convenience of your readers, so I have searched for it myself, to no avail.  Please provide a link.

And what, pray tell, is "Howell"?  You use that word, and even have it imbedded in one of the quotations.  If it is a misspelling of something else ("Howland"?), then it calls into question your entire premise, since you imply that you are quoting verbatim some work of [Bob] Brandenburg, and I doubt seriously that he would have used the incorrect name of "Howell." 

I also wonder why you shortened the reference to this document ("the Brad(shortened name) report"), and then only use that shortened term one other time -- in the very next sentence.  Why was it necessary to shorten "Brandenburg" (which at least conjures up the name of a known contributor to the work of TIGHAR) to the obscure "Brad"?

I look forward to reading the rest of your post as soon as you have provided a link to the document upon which you lay your premise. 
Title: Re: Post loss Transmissions. Solved?
Post by: dave burrell on September 14, 2012, 09:03:50 AM
Bruce I am not sure how you missed them on your search but if you look in the archives under "catalog and analysis of radio signals during the search for Amelia Earhart in 1937, you will find several subsections. I will not quote them all due to space and typing one finger on a tablet, but the quotes transmit the gist of the report as far as it pertains to transmitters in the immediate area.
Quote" no central pacific ground station transmits on 278 kz or received on 3105 kz.
Therefore other the Itasca, Earharts electra was the only plausible source." end quote.
 pretty darn clear stance by Brandenburg. Except it is incorrect.


Now I am sure there are grammatical mistakes there as well. Sorry about spelling.
The point remains. That Bradenburg statement of "no other land based pacific transmitter" is clear. It is also incorrect.

Also in the archives of Tighar it has a category titled "Were their hoaxes?"
The response from Tighar partially paraphrased but intent unaltered,
"a hoaxer would need a suitable transmitter, adjust the modulation, and would need to position himself in that remote corner of the pacific and must have had advance knowledge that Earhart was not going to make Howland. Given the numerous restraints  the likelyhood of an event(hoax), is vanishingly small."


The position is clear, per Tighar there was no other reasonable known sources capable for these transmissions, other than its triangulation on Gardner. That much is also reaffirmed by Bradenburg never even mentioning Baker or Howland in his well drafted paper that lists possible hoax sites all over,  including Russia, and parts of the US mainland.
He both states there is no pacific source, then confirms his own statement by not listing any other central pacific source in his study. Why would an island like Baker, close by Howland, having teenagers on it, in the "action" so to speak, be left off the study of possible places a hoax signal could originate?

If he knew of the transmitters on baker and howland he never mentioned or studied their results against his treatise.

The records are there, he either did not know these were occupied islands with transmitters, or he willingly left the most obvious and closet transmittors out of his analysis on possible hoax sites.


Title: Re: Post loss Transmissions. Solved?
Post by: Bob Lanz on September 14, 2012, 10:19:24 AM
How to insert links in posts. (http://tighar.org/smf/index.php/topic,127.0.html)
Title: Re: Post loss Transmissions. Solved?
Post by: Bob Lanz on September 14, 2012, 10:27:59 AM
How to Quote and trim quoted material from posts. (http://tighar.org/smf/index.php/topic,392.msg4493.html#msg4493)
Title: Re: Post loss Transmissions. Solved?
Post by: dave burrell on September 14, 2012, 03:19:54 PM
Jeff, you probably won't see it unless you read the history carefully.
Ric was off a year in the issuance of radios. A small mistake. I sent you the link, radios were actually installed in 1935 for the first colonists...now follow the trail.. the highschoolers left....  they packed up and left and took their radio.
I guess that was better than leaving all their stuff on a deserted island unprotected.
BUT... they came back in a few months. It is indisputable Baker, Jarvis, Howland had students from 1935 to 1942.

Ric even states in his history of the minor islands that due to safety concerns radios were installed in 1936. So I guess you are saying the subsequent batches of students had no radios for 7 years? Maybe subsequent students weren't as worried about? :)

But to satisfy any further doubts,
Here is ANOTHER link, and BTW most of this is in the archives, where Hooven talks about Baker radios in 1937, a second hand source, but really, this whole issue is not even in dispute with any common sense applied. They didn't drop people off there for 7 years with no radio. Or give the colonists on Baker radios in 1936(per Ric), and then snatch them back, just in time for Amelia Earhart.

http://tighar.org/Projects/Earhart/Archives/Documents/Hooven_Report/HoovenReport.html

"Commander Thompson reasoned that if the plane were down it was most likely to the North of Howland. There had been clouds to the north, while the weather was clear to the south. Reasoning that the plane must have been in overcast weather, and that it would surely have seen Baker Island, 40 miles south of Howland, if it had been to the south, he set off at once to the NNW along the position line. He was assured that the plane’s large fuel tanks, when empty, had more than enough flotation to insure that it would remain afloat if it had landed in the water without crashing. There was Baker Island to the south of Howland, where there was a party with a radio receiver and a small transmitter, and then 340 miles to the SSE was McKean Island, even smaller than Baker or Howland, the nearest of the Phoenix group, a scattered group of islands, the largest of which was only about eight square miles in area.



The radios were there Jeff, all the time from almost the beginning months of 1935 until 1942, except a month or so in between expeditions. That is common sense for safety. That is the fact. That is the gorilla.
Why that Gorilla was not mentioned in the Brandenburg report, ask Him and Tighar. It would seem obvious when studying sources of Post loss transmissions to mention radios at the scene of the action, instead of putting out a report stating there were no land based radios capable of doing these transmissions in the entire central pacific.
Title: Re: Post loss Transmissions. Solved?
Post by: Alan Harris on September 14, 2012, 06:51:50 PM
At my last understanding it is difficult to transmit from a radio antenna without a radio transmitter and an operator.

On the other hand, it would seem at least equally difficult to accomplish one of the colonists' primary missions as described by US House Resolution 388, 112th Congress (http://www.govtrack.us/congress/bills/112/hres388/text) to provide radio communication if radios were not present for the majority of the time . . .

Quote
Whereas, on March 30, 1935, the United States Coast Guard Cutter Itasca departed from Honolulu Harbor in great secrecy with 6 young Hawaiians aboard, all recent graduates of Kamehameha Schools, and 12 furloughed army personnel, whose purpose was to occupy the barren islands of Howland, Baker, and Jarvis in teams of 5 for 3 months;

Whereas in June 1935, after a successful first tour, the furloughed army personnel were ordered off the islands and replaced with additional Kamehameha Schools alumni, thus leaving the islands under the exclusive occupation of the 4 Native Hawaiians on each island;

Whereas the duties of the colonists while on the island were to record weather conditions, cultivate plants, maintain a daily log, record the types of fish that were caught, observe bird life, and collect specimens for the Bishop Museum;

Whereas the successful year-long occupation by the colonists directly enabled President Franklin D. Roosevelt to issue Executive Order 7368 on May 13, 1936, which proclaimed that the islands of Howland, Baker, and Jarvis were under the jurisdiction of the United States;

Whereas multiple Federal agencies vied for the right to administer the colonization project, including the Department of Commerce, the Department of the Interior, and the Navy Department, but jurisdiction was ultimately granted to the Department of the Interior;

Whereas under the Department of the Interior, the colonization project emphasized weather data and radio communication, which brought about the recruitment of a number of Asian radiomen and aerologists;

Whereas under the Department of the Interior, the colonization project also expanded beyond the Kamehameha Schools to include Hawaiians and non-Hawaiians from other schools in Hawaii;

Whereas in 1937, in preparation for Amelia Earhart’s arrival on Howland Island, the colonists constructed a landing field, readied a shower and bedroom for her, and prepared a performance for her, but she never arrived, having disappeared en route to the island on July 2, 1937.

[Emphasis added]
Title: Re: Post loss Transmissions. Solved?
Post by: Greg Daspit on September 14, 2012, 07:37:36 PM
If he did know radios were on these islands, Why did the report state there were no land radios in the central pacific?  (and please show me one reference where he analyized these transmittors). How can he ignore these radio sets mere miles from his Triangulation theory? And how can his report be valid since he is stating there were no transmittors in the area around Howland?

At the very least these radio transmittors should in my opinion be included in the brandenburg report of Post loss transmissions. Those radios should be analyzed to show whether they could account for all "post loss" transmissions.


Brandenburg's  Post-Loss Catalog (http://tighar.org/Projects/Earhart/Archives/Research/ResearchPapers/Brandenburg/signalcatalog3.html) does mention amateur radio operators on both Howland and Baker.
For example:
50910BR Ham Operator on Baker
50916HD Ham Operator K66NW on Howland
40650HD Amateur Radio Operator on Howland
40720BR Amateur Paul Yat Lum on Baker, See picture (http://www.flickr.com/photos/bishop_museum/5084584791/in/set-72157625047187285) of Paul Yat Lum
Seems they were trying to help and reported what they heard
There are also several from the "Itasca detachment" on Howland
Title: Re: Post loss Transmissions. Solved?
Post by: Bob Lanz on September 14, 2012, 08:29:15 PM
Quote
On the other hand, it would seem at least equally difficult to accomplish one of the colonists' primary missions as described by US House Resolution 388, 112th Congress (http://www.govtrack.us/congress/bills/112/hres388/text) to provide radio communicationif radios were not present for the majority of the time

Alan, your comment is a distortion of the US House Resolution.  Nowhere in that document does it say "one of the colonists primary missions" nor does it say "to provide radio communication".   It does however say, "the colonization project "emphasized" weather data and radio communication" as you indicated.  The operative word is "emphasized", not "mandated", as you would lead the readers to believe.  You are paraphrasing the intent of the Resolution to suit your position.
Title: Re: Post loss Transmissions. Solved?
Post by: Alan Harris on September 14, 2012, 08:43:42 PM
Quote
On the other hand, it would seem at least equally difficult to accomplish one of the colonists' primary missions as described by US House Resolution 388, 112th Congress (http://www.govtrack.us/congress/bills/112/hres388/text) to provide radio communicationif radios were not present for the majority of the time

Alan, your comment is a distortion of the US House Resolution.  Nowhere in that document does it say "one of the colonists primary missions" nor does it say "to provide radio communication".   It does however say, "the colonization project "emphasized" weather data and radio communication" as you indicated.  The operative word is "emphasized", not "mandated", as you would lead the readers to believe.  You are paraphrasing the intent of the Resolution to suit your position.

Of course it is obvious that I have paraphrased.  I disagree that I have "distorted".  I don't think the point of the post is changed at all if it said "On the other hand, it would seem at least equally difficult to accomplish one of the emphasized colonist activities of radio communication as described by US House Resolution 388, 112th Congress if radios were not present for the majority of the time . . ."

As far as paraphrasing, I never said anything about "mandated", you have paraphrased me.   :D
Title: Re: Post loss Transmissions. Solved?
Post by: dave burrell on September 14, 2012, 09:55:16 PM
If he did know radios were on these islands, Why did the report state there were no land radios in the central pacific?  (and please show me one reference where he analyized these transmittors). How can he ignore these radio sets mere miles from his Triangulation theory? And how can his report be valid since he is stating there were no transmittors in the area around Howland?

At the very least these radio transmittors should in my opinion be included in the brandenburg report of Post loss transmissions. Those radios should be analyzed to show whether they could account for all "post loss" transmissions.


Brandenburg's  Post-Loss Catalog (http://tighar.org/Projects/Earhart/Archives/Research/ResearchPapers/Brandenburg/signalcatalog3.html) does mention amateur radio operators on both Howland and Baker.
For example:
50910BR Ham Operator on Baker
50916HD Ham Operator K66NW on Howland
40650HD Amateur Radio Operator on Howland
40720BR Amateur Paul Yat Lum on Baker, See picture (http://www.flickr.com/photos/bishop_museum/5084584791/in/set-72157625047187285) of Paul Yat Lum
Seems they were trying to help and reported what they heard
There are also several from the "Itasca detachment" on Howland

THANK YOU! So can we put this issue of Amateur radios on Baker and Howland to rest now? The radios were there. They were there for two years before Amelia Earhart. But it doesn't matter how long.

The point is that there were AMATEUR, Not navy, not coast guard, but AMATEUR operators of radio sets at 3 known locations in the central pacific. Jarvis, Howland, Baker islands.( either operated by Hawaiian boys or new Chinese operators)
Just as I orginally posted.


Now that Branderburg himself referenced these, (thanks Greg for a nice find), maybe everyone can agree there were radios and not dispute that issue anymore. I thought I was going to have to find a picture date stamped 1937 baker island showing a guy talking into a headset. ;)

So there were amateur(or chinese) radio HAM operators, we can all agree, on these islands for Weather and communications duties. Were these same operators the actual source of all post loss transmissions? Bradenburg uses their receiving information as possible important information, as they were "trying to help",per Greg, but totally eliminated them as a SOURCE of the transmissions. If you look at 40650HD we have a radio operator stating he got a strong hit, and Brandenburg stating that could be gardner island.

(So he is pretty accepting of information by amateur operators when it fits his theory. )

But in his summary report Brandenburg states there were no land radios in the entire central pacific capable of making these post lost transmissions.
See the conflict?  It does seem he has made a giant assumption- that radio operators that reported anything were trying to help.
Well anyone who has been a fireman or policeman can tell you that a lot of times people "trying to help", are the people actually setting the fires. How many times have we all read of a low paid security guard, or volunteer fireman been found to cause more issues attaching themselves to a situation?

There was great excitement no doubt of the colonization of these minor islands, high schools kids, 17-18 years old had made newspapers in major cities saying they were making history, congress was applauding their efforts, the president was now declaring that thanks to them we had expanded the actual territory of the United States.

Pretty Heady stuff for some teenagers and amateurs.
Now boredom was a problem, but then they get a report that the famous Amelia Earhart was coming in. Preparations were made. Richard Black from the Interior department came, newsmen came. Then Amelia never made it.
The search was on and listening to radio signals from Hawaii everyone could hear the pleas that Amelia just key her microphone, let us know you are alive.

So l expect that a hoaxer, a small prank, someone even well meaning wanting to keep the search going might have keyed that mike on Baker or Howland Island.
For Brandenburg to totally eliminate that possibility and make the sweeping the statement that there was no land based radios capable of producing this triangulation may mean one of a couple of things,

1 he was not aware there were Amateur operators on Baker and Howland, which seems unlikely now. Some will argue that these young Chinese operators were not "amateur" but that is weak. We have no idea who controlled these land based radio sets 24/7 and the Amateur Hawaiians had been doing it long before the newly arrived Chinese, if any were on duty.. whichever operator had the actual headset on, they took breaks, which allowed plenty of time to key a microphone a few times. This was not the Navy.

2 he was aware of these land based transmitters and never even considered the possibility that these  operators could be the source of all the post loss transmissions.
In either event, it is flawed. If the report is read in summary it seems there was no way a hoaxer could have made these signals.

How many times have I read "what are the chances a hoaxer could have been in the area of triangulation, the logistics argue against that" or words to that effect, leaving the impression that in this great big triangulation there were only Navy searchers, and it would be impossible for a hoaxer to transmit.

The reality is much simplier, but was left off the final summary of the Branderburg report.
 Baker/Howland Island Amateur Hawaiian student operators(or newbie chinese operators) could in fact account for all these so called "post loss" radio transmissions.


Title: Re: Post loss Transmissions. Solved?
Post by: pilotart on September 14, 2012, 11:17:44 PM
Quote
Those radios should be analyzed to show whether they could account for all "post loss" transmissions.
Yes, what frequency's did those Island Radios transmit on?
Title: Re: Post loss Transmissions. Solved?
Post by: Greg Daspit on September 14, 2012, 11:55:30 PM
The HAM operators were known to the professional operators based on their reporting to the Itasca and in the case of Howland, the Itasca detachment was on the same small island. They were also in an isolated area.  It does not make sense to me to try to pull off a radio hoax if your next door neighbor is a radio professional who works for the government and very few others nearby it could be blamed on.
Title: Re: Post loss Transmissions. Solved?
Post by: dave burrell on September 15, 2012, 06:43:35 AM
The HAM operators were known to the professional operators based on their reporting to the Itasca and in the case of Howland, the Itasca detachment was on the same small island. They were also in an isolated area.  It does not make sense to me to try to pull off a radio hoax if your next door neighbor is a radio professional who works for the government and very few others nearby it could be blamed on.

They were not professional operators. They were also kids, with little training, thrown in with high school student alumni. Brandenburg himself distinguished them by calling them "amateurs". There were serious questions on young Paul Yum at the time, when he claimed to hear AE's voice and nobody else did. I think this shows the level of competence. This was not Pan Am. These were low paid operators who look younger than the older students on Baker. Apparently they were also prone to flights of fantasy as well, that were not accepted by the Navy.

For instance, On reception 40650 you had one Amateur operator from Howland calling the Itasca claming that the Baker Amateur called him saying he heard Amelia talking. WOW. Nobody else heard it. But supposedly loud and clear signal 5 to this one operator Amelia talking and he heard it clearly. Nobody believed that.
So there are very serious issues with all these transmissions with amateur ham operators.

Paul Yum also claimed the JAPANESE SHOT DOWN AMELIA EARHART, AND REMEMBERS HER TRYING TO LAND AT NIGHT.
http://tighar.org/Projects/Earhart/Archives/Forum/Forum_Archives/200608.txt

In reality you had a radio shack on these islands, Baker and Howland, with 4 older Hawaiian students, and a young unskilled chinese operator per island. All trying to "help" and be part of this exciting action. Some of them claiming to hear transmissions their counterparts 35 miles away never heard.
Again, people who want to be "part of the action", exaggerate, hear things that did not happen, and sometimes "start the fires themselves"

Now whether you or I or anybody believe that one or more were trying to pull a hoax or were simply incompetent, like leaving a mic keyed for a continuous carrier wave, the fact was that land based radios not operated by the Navy or Coast guard were in the area.
Not "next door", but 35 miles apart, and in the case of Jarvis 1000 miles East.

Were these radio shacks the cause of the post loss transmissions?
POSSIBLY THEY WERE.
We will never know for sure.
But my opinion is they should have been included in Brandenburgs study of possible sources, instead of the statement that "other than the Itasca, there were no other plausible sources for these transmissions"
He lists the Itasca as a plausible souce with real professional operators, but dismisses it. Ok. Fair enough.
But then Brandenburg fails to mention at all the other plausible sources on Baker and Howland Island.
So it's not as cut and dried as the final summary makes it appear. To the person reading his report, Bradenburg implies there is the Navy searchers, and nobody else in the entire central pacific.
He then submits the Midway, Wake, ect. receptions and then triangulates them to near Gardner without mentioning they also triangulate to Baker as  well.
What I am saying, and what I have brought up (with a question mark), is maybe there is another source Brandenburg never listed  for these transmissions.

I will leave it at that for each to decide. But my research is sound, the possibility for post loss transmissions was there. It is also my opinion those possibilites should have been included in the final report as well.
Title: Re: Post loss Transmissions. Solved?
Post by: dave burrell on September 15, 2012, 02:51:19 PM
Thats fine Jeff. It is being mentioned as a hypothesis for post transmissions other than what you already knew about.
That is all it was meant to do.
I make no claim any of the teenagers on Howland or Baker misused the radios to send out hoax transmissions.
But they might have, and that is my entire point.
Brandenburg totally ignored that possibility by saying if it wasnt the itasca sending these signals, then there was no other plausible source but Earhart.
Well now you know about two other land based places within his triangulation.
You now have more choices than just Earhart on an atoll.
Title: Re: Post loss Transmissions. Solved?
Post by: Alan Harris on September 15, 2012, 03:27:20 PM
Well now you know about two other land based places within his triangulation.

Speculating only, Jarvis might also be in the intersection area of the bearings within a plausible error band, making it three.  There has been some discussion of appropriate error bands in another thread (http://tighar.org/smf/index.php/topic,940.0.html).
Title: Re: Post loss Transmissions. Solved?
Post by: Jeff Carter on September 15, 2012, 03:32:11 PM
Many of the transmissions rated as credible do not require a deliberate hoaxer, because the transmissions received were too short, faint, or noisy.  In those cases, almost any transmission with the proper frequency would suffice to fit the reported transmission, i.e., an amateur operator could be trying to help by calling KHAQQ, trying to respond to a message they heard, inadvertently pressing the transmit key, or simply fooling around.     

For example http://tighar.org/Projects/Earhart/Archives/Research/ResearchPapers/Brandenburg/signalcatalog3.html --  40834PU, "Immediately following the KGU broadcast at 0833Z, the Pan American station at Mokapu heard a faint carrier on approximately 3105 kHz, but the signal was too weak to distinguish any words." or 41215WD  -- "Wake heard an intermittent male voice, of “rather wobbly characteristics.” Atmospheric noise prevented understanding what was said. At 1210Z, Wake heard several unreadable voice signals near 3105 kHz, in noise."
 
Title: Re: Post loss Transmissions. Solved?
Post by: dave burrell on September 15, 2012, 04:07:18 PM
Many of the transmissions rated as credible do not require a deliberate hoaxer, because the transmissions received were too short, faint, or noisy.  In those cases, almost any transmission with the proper frequency would suffice to fit the reported transmission, i.e., an amateur operator could be trying to help by calling KHAQQ, trying to respond to a message they heard, inadvertently pressing the transmit key, or simply fooling around.     

For example http://tighar.org/Projects/Earhart/Archives/Research/ResearchPapers/Brandenburg/signalcatalog3.html --  40834PU, "Immediately following the KGU broadcast at 0833Z, the Pan American station at Mokapu heard a faint carrier on approximately 3105 kHz, but the signal was too weak to distinguish any words." or 41215WD  -- "Wake heard an intermittent male voice, of “rather wobbly characteristics.” Atmospheric noise prevented understanding what was said. At 1210Z, Wake heard several unreadable voice signals near 3105 kHz, in noise."

Great point Jeff. It did not have to be an intentional hoax. Simply someone trying to help, contacting a friend,  or fooling around with the radio as you mention.
With 2, or 3 additional land based radio sets out there within the area of triangulation, there could be a very innocent answer for all these post loss transmissions. It certainly opens up the possibilites.
Title: Re: Post loss Transmissions. Solved?
Post by: Greg Daspit on September 15, 2012, 05:08:09 PM
Quote
Those radios should be analyzed to show whether they could account for all "post loss" transmissions.
Yes, what frequency's did those Island Radios transmit on?

Some info from the forum archives (http://tighar.org/Projects/Earhart/Archives/Forum/Forum_Archives/200201.txt) referencing mail from Yau Fai Lum:
"We worked for the Dept. of Interior, three Hawaiians from Kamehameha School
and myself, the radio operator. I had a SW3 radio receiver and a home built
transmitter with a 807 in the final. The Zepp antenna hung from the top of
the flag pole to a shorter pole 65 feet away. Our electrical sources were
borrowed from the army with their hand-cranked generator which put out 400
volts, storage batteries together with a generator-charger, and a dynamo. I
had special authority from the FCC to operate on 31 meters on the Coast
frequency because the ham bands had too much QRM"
Title: Re: Post loss Transmissions. Solved?
Post by: pilotart on September 15, 2012, 06:15:37 PM
<...>I make no claim any of the teenagers on Howland or Baker misused the radios to send out hoax transmissions.
But they might have, and that is my entire point.
Brandenburg totally ignored that possibility by saying if it wasnt the itasca sending these signals, then there was no other plausible source but Earhart.
Well now you know about two other land based places within his triangulation.
You now have more choices than just Earhart on an atoll.
Brandenberg would have totally ignored those Island Radios because they could not Transmit on the 3105 kHz (or 6210 kHz) frequencies.

Prior to WW2, those were Aircraft Transmitting Frequencies and Itasca had (for the Earhart watch) the special Crystal needed to Transmit.

The Electra had the capability to transmit on 500 kHz (no long trailing antenna and no Post-Loss receptions reported on 500 kHz) 3105 kHz and 6210 kHz.

All of the credible Post-Loss Receptions were on 3105 kHz and 6210 kHz or Harmonics of those frequencies.

Thank you Gregory Lee Daspit for digging up this information:
Quote
Those radios should be analyzed to show whether they could account for all "post loss" transmissions.
Yes, what frequency's did those Island Radios transmit on?

Some info from the forum archives (http://tighar.org/Projects/Earhart/Archives/Forum/Forum_Archives/200201.txt) referencing mail from Yau Fai Lum:
"We worked for the Dept. of Interior, three Hawaiians from Kamehameha School
and myself, the radio operator. I had a SW3 radio receiver and a home built
transmitter with a 807 in the final. The Zepp antenna hung from the top of
the flag pole to a shorter pole 65 feet away. Our electrical sources were
borrowed from the army with their hand-cranked generator which put out 400
volts, storage batteries together with a generator-charger, and a dynamo. I
had special authority from the FCC to operate on 31 meters on the Coast
frequency because the ham bands had too much QRM"

The 31 Meter Band (http://en.wikipedia.org/wiki/Shortwave_bands) is 9400–9900 kHz.
Title: Re: Post loss Transmissions. Solved?
Post by: dave burrell on September 15, 2012, 08:05:52 PM
Yum says he got special permission to transmit at 31 meters because he preferred it for less interference. Not that he had to use that frequency only. He was obviously transmitting to Ham stations on the west coast, he was transmitting to the Itasca, to the other island, and I doubt he was always up to 9000kz. So to interpret one operator saying he had permission to transmit at 31 doesn't mean he was restricted to one frequency range, and had no capability to transmit in the 3105kz range.
Show me the quote in Brandenburgs report where he claims that  ALL the amateur operators on Baker and Howland and Jarvis were restricted to 31 meter transmissions so he 'disregarded' them. That the actual sets on all the islands could not transmit at 3105 that is. He knows this how?
I must have missed that statement.
Title: Re: Post loss Transmissions. Solved?
Post by: pilotart on September 15, 2012, 08:42:58 PM
Dave,

You missed the point, which was that the Island Radio Transmitters would have been unable to transmit at all on 3105 kHz or 6210 kHz.

Those are the only frequencies (with their harmonics) reported for Post Loss Radio Receptions.

Unlike receivers, you don't just 'tune' across a dial to select a transmitter frequency, instead you select a crystal to tune your transmitter to your exact transmission frequency.

For the Island Radio operators to have purchased 3105 kHz Transmitter Crystals and installed them in their transmitters would have violated FCC regulations.
   They were a long long way from 'Radio-Shack' anyway.

More information from Yau Fai Lum (http://tighar.org/Projects/Earhart/Archives/Forum/Forum_Archives/200201.txt)
Quote
I was never in radio contact with Earhart, for that was left entirely to the
Coast Guard. My SW3 receiver only had a few coils in the ham bands and two
that I wound to receive the Coast Guard frequency on 31 meters and a
broadcast coil to receive KGMB in Honolulu. I do not know anything about
hearing signals from Earhart after she went down.

So he could not even receive on Earhart's Frequencies, let alone transmitt.
Title: Re: Post loss Transmissions. Solved?
Post by: dave burrell on September 15, 2012, 09:01:35 PM
Understood. I don't think "against FCC regulations" means a whole lot with a homemade set in the Pacific, but conceding that, in Bradenburgs report one of the operators, maybe not Mr.Yum, but  Baker island claimed he heard Ms.Earnhart on 3105khz.  report 40650.
So which is it? Yum says they couldn't hear Amelia. Brandenburg claims a report was made they could, and did.

It then says Baker radioed Howland, that radioed the Itasca.
So now that he is interviewed 50 years later and says he didn't have the capability to receive the transmissions? In fact denies that he knows a thing  about post loss transmissions from AE.
CLEARLY THAT IS NOT TRUE.

I do know for sure it's in the report, but it doesn't say which operator on Baker heard AE talking on 3105.
So somebody on one of those two islands had a capability Mr.Yum later said they did not have the capability to have. Clearly both operators were aware of this transmission at the time.
Did they also have the capability to transmit on 3105 that Mr.Yum claims he didn't have the capability to make? Since Howland and Jarvis were planned and plotted airfields by 1935, is it unreasonable to expect the radio operators at those airfields to have a set able to talk to pilots?
Did Mr.Yum have the exact same homemade radio as the other islands?

But all in all, If he doesn't remember making a false report of hearing AE at the time, and claims it was impossible to, when clearly it was done,  I kind of doubt his remembrance of the crystals he had in his "home made" set in 1937.


Title: Re: Post loss Transmissions. Solved?
Post by: Alan Harris on September 15, 2012, 09:07:41 PM
. . . doesn't mean he was restricted to one frequency.

Disclaimer:  I just know I'm going to regret this post, because I don't know beans about radio in general, or particularly in the 1930's.  So feel free to kill me now, lol.

Something seems fishy to me about Lum's recollections.  Scrolling through the Jacobson Database (http://tighar.org/Publications/Books/FindingAmeliaNotes/JacobsonDatabase/RADIOLOG/RADREST.PDF) of radio signals, it seems indisputable that Howland was transmitting on several frequencies:

Often on 24 meters (~12500 KHz) when working Baker Island and scheduled sessions with Honolulu

Often on 2670 KHz when working Itasca

And then there is one tantalizing reference where Itasca asks Howland to transmit on 3105 Khz, suggesting that at least USCG thought Howland had that capability?

Quote
____________________________________________________________________________________________________________________

FROM: ITASCA
TO: HOWLAND
DATEZ: 07/05/37 TIMEBZ: 0306
DATEL: 07/04/37 TIMEBL: 1536 FREQUENCY: 3105.00
LITERAL: K6GNW DE NRUI ZFN FL (3105)
TRANSLATION: ITASCA CALLING AMATEUR STATION, HOWLAND ISLAND, SHIFT TO TRANSMIT AND RECEIVE ON FL, ON
3105 KHZ
SOURCE: ITASCA2 RECORD NO.: 1222
___________________________________________________________________________________________________________________


As to "couldn't even receive on AE frequencies" there are a ton of references where both Howland and Baker are either asked to, or report, listening for AE on 3105, and from the context it seems clear that these did not all refer to the HF-RDF unit.  In fact Baker had no RDF unit.

OK, gritting my teeth and ready for 50 people to tell me why this post is stupid.    :)
Title: Re: Post loss Transmissions. Solved?
Post by: dave burrell on September 15, 2012, 09:14:51 PM
Not stupid at all Alan. Nice points. For someone who now says he could only transmit around 9500 KhZ, he was doing a lot of talking and receiving on a wide range of different frequencies to everyone.

Yum is also claiming he doesn't know a thing about
AE post loss transmissions in his interview.
But we have report 40650 where it states he would have had to known, and would have either received it himself, or transmitted it to the Itasca, a report of a transmission of Amelias voice he claimed he heard on 3105. A total contradiction.
Mr.Yum's recollections seem to be shaky on what capabilities he had, what he received, and what he transmitted.
To put it mildly.

Human memory is a frail thing. I think this nice man's memory is a bit off when matched against the Itasca's records and the records of multiple transmissions on different frequencies from the islands.
What is known for sure, there were radio sets on these 3 islands pre flight of AE. That is the known Fact nobody disputes.( well somebody could dispute anything I guess. :))
Were multiple transmission frequencies used? The total evidence to me strongly suggests that is the case. Was the frequency 3105 used for transmission by the islanders? Unknown, though we do have at least one official report asking the islanders to use it.
We do not know exactly what radio sets were used on each island and what capabilities they had.

Given all those variables, it would seem impossible to rule out any of the 3 outlying minor islands as a source of the AE post loss transmissions..
Title: Re: Post loss Transmissions. Solved?
Post by: Mark Pearce on September 15, 2012, 11:28:45 PM

...Mr.Yum's recollections seem to be shaky on what capabilities he had, what he received, and what he transmitted.
To put it mildly.



...Something seems fishy to me about Lum's recollections. 



Ron Bright also saw problems with Yau Fai Lum’s story.

"The strange case of Yau Fai Lum's denial" (http://tighar.org/Projects/Earhart/Archives/Forum/Forum_Archives/200806.txt)

Date: Mon, 9 Jun 2008 15:47:36
From: Ron Bright

"...I am looking for a possible answer to Lum's inexplicable "amnesia" in view of his rather impressive credentials as the Head of the Honolulu Police Communications Dept. How could one forget a momentous event such as hearing a post loss signal from AE?..."


Title: Re: Post loss Transmissions. Solved?
Post by: pilotart on September 16, 2012, 12:01:16 AM
What Yau Fai Lum said was that "I had special authority from the FCC to operate on 31 meters on the Coast frequency because the ham bands had too much QRM".

That's not saying "Only" on 31 Meter Band, he did say that he operated on Ham Bands as well.  For "Official" work he was authorized to use that Official Coast [Guard] frequency with less interference.

That would not be an authorization to use an Aircraft frequency.

FCC is quite strict about which and how you use transmitting frequency's, Ham Bands can't be used for 'business' and non-Ham can't be used for 'chit-chat' and Aviation Frequency's can't be used by Amateur Stations.

Anyone with the correct coil in their receiver can receive whatever they want on any frequency at any time.

It was a surprise to me that Yau Fai Lum would say that his equipment could not receive Earhart's frequencies.  I just copied what he wrote (http://tighar.org/Projects/Earhart/Archives/Forum/Forum_Archives/200201.txt) in 1989.  The Colonist Operator on Baker Island was quite adamant about hearing Amelia's Post-Loss Transmissions.

Ron Bright also saw problems with Yau Fai Lum’s story.
The only answer I can think of was the 'official' reluctance to consider 'Post-Loss' Radio Receptions after the search had ended.  That opinion still exists. ;)

You will have to ask Randy Jacobson to explain that radio log entry, but Itasca had transferred equipment to Howland.  Their portable transmitter had problems communicating with the Itasca and Yau Fai Lum was reported to have done that for them on his 31 Meter Coast Guard Frequency.

If you want anyone to believe that the Island Radio Operators were a possible source of bogus Post-Loss Radio Signals, you will have to establish that they had the illegal crystal (http://en.wikipedia.org/wiki/Crystal_oscillator) to transmit on Earhart's Aviation Transmitting Frequency's with their equipment.
Title: Re: Post loss Transmissions. Solved?
Post by: Greg Daspit on September 16, 2012, 12:09:08 AM
This is getting confusing with a "Mr Yum" now in the picture.
Here is how I see it:
There appears to be a Yau Fai Lum on Howland who is not the same as Paul Yat Lum on Baker. Mr Lum on Baker said he heard Amelia. The Lum on Baker does not appear to have the ability to transmit directly to Itasca. Mr. Lum on Baker contacted Howland so they could contact Itasca with what the Lum on Baker heard. Mr Lum on Howland may not remember transferring this because it was 50 years later when he mailed his letter (http://tighar.org/Projects/Earhart/Archives/Documents/Letters/YauFaiLum.pdf) and his letter started off by stating it had been 50 years and he was not sure about his memory. Also there appears to be more than one operator on Howland manning the station with both the island radio set and a radio set with DF capability brought there by the Coast Guard "Itasca detachment" to help with AE
Please see the Howland Radio log (http://tighar.org/Projects/Earhart/Archives/Documents/Logs/HowlandRadioLog.pdf) for more information about the RDF radio set brought ashore by the Itasca which was borrowed from the Navy.

I would like to see a link where there was an island based radio set capable of transmitting on 3105 or 6210 on Howland, Baker or Jarvis.

edit: Thank you Art for the explaination of the ability to transmit on the post loss frequency, FCC regulations and the difference between transmitting and recieving.
Title: Re: Post loss Transmissions. Solved?
Post by: Gary LaPook on September 16, 2012, 01:58:24 AM

If you want anyone to believe that the Island Radio Operators were a possible source of bogus Post-Loss Radio Signals, you will have to establish that they had the illegal crystal (http://en.wikipedia.org/wiki/Crystal_oscillator) to transmit on Earhart's Aviation Transmitting Frequency's with their equipment.
Sorry, but you are operating under a misapprehension. Although it has been common for aircraft radios to be crystal controlled (and other types of radios designed to be operated by people without special knowledge and training such as CB radios), transmitters operated by trained individuals are more often tuned by use of a VFO, a "variable frequency oscillator," which allows tuning to just about any frequency you want, just like a common AM receiver. In order to get a ham license you must pass a test on radio design (this is one of the purposes of the Amateur Radio Service, to promote this type of education) so every one of the hams on those islands had the knowledge to modify and tune their transmitters to operate on 3105 kcs. This would have been especially easy (trivial, actually) since it was so near to the standard ham frequency band of 3500 to 4000 kcs, so would require only a very slight tweaking of the coil or capacitor in the VFO.  It was very common then, (less common now that commercially manufactured ham radios are easily obtainable), for hams to design and build their own transmitters from scratch, many hams take pride in their ability to do this and in the quality of the signal put out by their "home brewed" transmitters. I have built several transmitters myself and none were crystal controlled. The same is true of the Itasca, they had professional technicians and also did not have a crystal controlled transmitter, as you stated in a prior post, so could adjust the tuning components of their transmitters to cover the frequencies requested by Earhart, 3105, 6210, and 7500. And just how did you think that they got their transmitters up on 31 meters (9000 kcs), it takes more than just inserting a crystal to make that large a change in frequency, it takes adjusting the taps on many of the coils and possibly modifying or replacing some capacitors in order to modify a radio to work on a frequency this far away from the previous operating frequency. This is a much larger modification than the trivial adjustment to operate on a frequency only 400 kcs removed from the prior standard ham frequency of 3500 kcs. It is obvious that if the hams could make the modification to operate on the 9,000 kcs band that they could make the much less significant change to tune to 3105 kcs.

The next time you are at your local library look for the ARRL Handbook  (https://tighar.org/smf/Sorry, but you are operating under a misapprehension. Although it has been common for aircraft radios to be crystal controlled (and other types of radios designed to be operated by people without special knowledge and training such as CB radios), transmitters operated by trained individuals are more often tuned by use of a VFO, a)(Amateur Radio Relay League) which has been published since 1926, and you will see hundreds of plans for building various types of transmitters. Or go here to see examples (http://vintageham.com/projects.htm) of home brewed transmitters made from scratch by hams using 1930's technology and some from plans published in the early editions of the ARRL Handbook and in the ARRL magazine, entitled QST. I have attached a photo of one such transmitter made from plans in the 1932 Handbook, it covers 3500 kcs (and other bands) and is tuned with a variable capacitor, not a crystal in sight. This transmitter could be retuned to work on 3105 kcs, possibly just by simply bending the coils so that the spacing of the turns is slightly different.



gl
Title: Re: Post loss Transmissions. Solved?
Post by: Alan Harris on September 16, 2012, 02:04:53 AM
You will have to ask Randy Jacobson to explain that radio log entry

I expect he could only say it came from the radio log of the Itasca.  More specifically he is just transcribing from the source he calls "Itasca2" (http://tighar.org/Projects/Earhart/Archives/Research/JacobsonDatabase/RADIOLOG/RSOURCES.PDF):

Quote
ITASCA2: Smooth log of position number 2 of the Itasca radiolog, from 1900 local time
on July 1 to 0825 local time, July 7, 1937. This log was the monitor of Earhart
communications, watched primarily by LG Bellarts and GE Thompson. Found in National
Archives, Record Group 26, 601, Entry 283B, Box 448: “Alaska to Amelia Earhart”.
Title: Re: Post loss Transmissions. Solved?
Post by: Adam Marsland on September 16, 2012, 03:18:27 AM

If you want anyone to believe that the Island Radio Operators were a possible source of bogus Post-Loss Radio Signals, you will have to establish that they had the illegal crystal (http://en.wikipedia.org/wiki/Crystal_oscillator) to transmit on Earhart's Aviation Transmitting Frequency's with their equipment.
It is obvious that if the hams could make the modification to operate on the 9,000 kcs band that they could make the much less significant change to tune to 3105 kcs.]

Interesting.  So again we have another situation where something is theoretically possible, assuming somebody wanted to go through the time and effort. but not necessarily likely nor even logically motivated given the actual prevailing circumstances at the time.  So assuming this is all correct, and I do find this information new to me and quite fascinating, I then have to ask: what would be their reason for making such a non-trivial modification to be able to transmit on an aircraft frequency?  How long would it take, would the materials for same be readily available on an island isolated from supplies, and would it inhibit their ability to use the radio as it normally would be used?  Also, would they be able to easily determine whether they were tuned correctly after such modifications were made, and whether they had tuned it properly back?

Not snark; honestly want to know.  I have no idea, these are just the questions that instantly pop into my mind when this kind of scenario is raised.  This does sound to me like another one of those things that could theoretically have happened but are a stretch in the real world but I don't have the HAM technical knowledge to know just how simple this would be (unlike the earlier suggestion that post-loss broadcasts could have been easily assembled with Amelia's voice from newsreels and such using technology at the time, which working in sound as I do, I know is not the case) so Gary, I do defer to you on that score...interested to hear more.
Title: Re: Post loss Transmissions. Solved?
Post by: Mark Pearce on September 16, 2012, 08:00:01 AM

"...But, I think others have said it well enough already."
 

Captain Friedell of the Colorado probably said it best way back in 1937-

“…There was no doubt that many stations were calling the Earhart plane on the plane’s frequency, some by voice and others by signals.  All of these added to the confusion and doubtfulness of the authenticity of the reports.”
Title: Re: Post loss Transmissions. Solved?
Post by: dave burrell on September 16, 2012, 10:02:22 AM

"...But, I think others have said it well enough already."
 

Captain Friedell of the Colorado probably said it best way back in 1937-

“…There was no doubt that many stations were calling the Earhart plane on the plane’s frequency, some by voice and others by signals.  All of these added to the confusion and doubtfulness of the authenticity of the reports.”

Mark that does indeed seem to sum it up.  A lot of transmissions to AE. A lot of radio sets in action at the same time, and as Gary nicely pointed out, the land operators could indeed transmit on the 3105 frequency if they so desired. Which makes sense. If I were on Baker Island in 1937 I would want as many transmitting frequencies as I could get.  :)

It is fascinating that much of this was argued back in 2002 and 2008 as well.
Seems I have brought up what others saw as a big issue as well.
The archives are littered with "the strange case of Mr.Yum" and conspiracy theories of coast guard coverups, and log books being changed, and Mr.Yum's denials of receiving AE. Two Mr.Yums. All Very interesting.

So, we do know there were radios on those islands. That point is critical.
How many radio sets? Unknown.
Did Mr.Yum do any or all the post transmissions himself, and is he believable? His memory conflicts with dated records and his denial of knowing anything about post loss transmissions is not credible in my opinion.
Was it possible for the islanders to transmit on the frequencies later reported as coming from AE? It would seem highly probable.

Therefore, I don't think postulating the island operators themselves responsible for some or all of the post loss signals is farfetched.  Nor is revisiting this issue trivial or just a "nice" theory.
It's a hardcore theory in the big picture of AE surviving days or weeks.
For if there is this much confusion on who was transmitting what and where and by whom, and there are allegations of logbook coverups and denials of the written logs, it is but a small leap to a hoaxer in the middle of that confusion. By accident or design.

If there were a hoaxer, well that would rattle a whole lot of theories about where she landed, (or splashed). A hoaxer could be a simple as someone wanting to get in on the "action", or by accident or design.
A simple hoaxer may have started and fed many on a false trail.

We have record of an island radio operator saying he actually heard Amelia talking, then he radios his friend, who then radios the Itasca. A transmission nobody else heard. Then the operator denies ever doing it. All of which sounds like a classic hoaxer.

For each to decide. For me, the post loss transmissions are the most "weighty" evidence that remains that points to a Gardner landing. However, those transmissions carry some huge question marks attached.




Title: Re: Post loss Transmissions. Solved?
Post by: Jeff Victor Hayden on September 16, 2012, 10:57:51 AM
A very interesting thread indeed.
One which may be resolved by simply checking transmissions from these possible sources during the dates concerned.
As Gary pointed out, it was a fairly simple task to adjust for the required frequencies...
so every one of the hams on those islands had the knowledge to modify and tune their transmitters to operate on 3105 kcs. This would have been especially easy (trivial, actually) since it was so near to the standard ham frequency band of 3500 to 4000 kcs, so would require only a very slight tweaking of the coil or capacitor in the VFO.
If we are able to confirm that transmissions were heard on their normal frequency to their
base during the dates concerned then it would follow that they were regularly changing the frequency of their sets back and forth as required.
Title: Re: Post loss Transmissions. Solved?
Post by: Alan Harris on September 16, 2012, 12:38:54 PM
One which may be resolved by simply checking transmissions from these possible sources during the dates concerned.

Very well said, that would be the key.  But I for one am not sure how to go about that.  We would need the radio logs from the stations on Howland, Baker, and Jarvis (if they kept complete logs) and I don't know if they have survived?  Failing that, there would be the logs from the recipients of transmissions from those places.  The only readily available source I know of there is the Itasca logs heroically compiled by Mr. Jacobson long ago, which cover Howland interaction only (no Baker or Jarvis).  As I noted in a prior post (http://tighar.org/smf/index.php/topic,944.msg19745.html#msg19745), the Itasca logs show Howland transmitting on 24 meters and on 2670 KHz, and Itasca once asking Howland to transmit on 3105 KHz.  (No mention of 31 meters, but absence doesn't prove a negative.)

As others have said, transmitting is the issue, receiving is more of a continuous capability over wide frequency bands.  From the various logs and reports it seems clear that both Howland and Baker could receive 3105 and there is no reason to suspect Jarvis would be different.

Also, as a tenuous speculation not related to the above: the original 1935 island colonists were asked to lay out airstrips for possible later use in surveys and eventually as trans-Pacific fueling stops.  It is not clear how much progress was actually made in this direction, but, could that have been a reason there would have been some pre-planning for the radios to be able to work aircraft frequencies?
Title: Re: Post loss Transmissions. Solved?
Post by: Greg Daspit on September 16, 2012, 01:12:39 PM
Howland operators did keep logs for Howland transmissions (http://tighar.org/Projects/Earhart/Archives/Documents/Logs/HowlandRadioLog.pdf). Mr Y.F. Lum on Howland was one of the operators who logged his entries.
The log shows that when the Howland operators transmitted, they did not transmit on 3105.
The Itasca also kept logs (http://tighar.org/Projects/Earhart/Archives/Research/Bulletins/37_ItascaLogs/PDF.html). Itasca logged when they transmitted on 3105.

Yes, some may have heard these Itasca 3105 transmissions and thought it was AE and it may have caused confusion as Friedel said. But they kept logs and Brandenburg prepared a catalog showing when Itasca transmitted on 3105 and when others heard something. I think this helped to clear up what Friedel called "confusion".

I think it may help address comments about hoaxes and modifying existing equipment by quoting the work in the Post loss catalog (http://tighar.org/Projects/Earhart/Archives/Research/ResearchPapers/Brandenburg/signalcatalog.html).
"The only known aircraft transmitters capable of transmitting on 3105 kHz were on U.S. and Canadian aircraft. Acquiring such a transmitter – or modifying existing equipment to transmit on 3105 kHz – in time to transmit hoax signals during the few days when post-loss signals were heard would be a daunting task for even the most technically talented would-be hoaxer.
The existence of the frequency band 3500 kHz to 4000 kHz, allocated for amateur (ham) radio operators, might suggest the possibility of ham hoax transmissions on 3105 kHz. However, in addition to the challenge of modifying equipment to operate on 3105 kHz on short notice, a ham would risk federal penalties for transmitting outside the assigned band limits.

But even if a hoaxer had a suitable transmitter, and was a woman or had a female accomplice, it would be impossible to control who would hear the signal, and thus impossible to direct the hoax to a specific target or group of targets. A hoax transmitter in the continental U.S. (CONUS) should have been heard by at least one of the 44 airport stations maintaining a continuous listening watch on 3105 kHz; a hoax transmitter on or near the west coast should have been heard by the special Coast Guard facility set up near San Francisco to listen for Earhart signals; and a hoax transmitter in Hawaii should have been heard loud and clear simultaneously at the Navy, Coast Guard, and Pan American Airways stations in Hawaii listening for Earhart signals. No such signals were reported"
Title: Re: Post loss Transmissions. Solved?
Post by: Jeff Carter on September 16, 2012, 02:32:25 PM
Post loss catalog (http://tighar.org/Projects/Earhart/Archives/Research/ResearchPapers/Brandenburg/signalcatalog.html):  "But even if a hoaxer had a suitable transmitter, and was a woman or had a female accomplice, it would be impossible to control who would hear the signal, and thus impossible to direct the hoax to a specific target or group of targets. A hoax transmitter in the continental U.S. (CONUS) should have been heard by at least one of the 44 airport stations maintaining a continuous listening watch on 3105 kHz; a hoax transmitter on or near the west coast should have been heard by the special Coast Guard facility set up near San Francisco to listen for Earhart signals; and a hoax transmitter in Hawaii should have been heard loud and clear simultaneously at the Navy, Coast Guard, and Pan American Airways stations in Hawaii listening for Earhart signals. No such signals were reported"

Its only fair that the same analysis apply to AE signals.  If AE was transmitting, it is difficult to understand how no receiver picked her up clearly, but all receivers heard only carrier waves, sporadic voices, faint dashes, etc.

Just a quick scan of the post loss catalog, shows stations listening included at least as a minimum: Itasca, Howland, Baker, Pan Am Wake, Pan Am Midway, Pan Am Hawaii, multiple Coast Guard Stations, HMS Achilles, New Zealand Star, Nauru Radio, Navy Wailupe & Navy Station Samoa. 

And from press reports, numerous ham radio operators in the United States and at least one ham operator in Melbourne, Australia.  One would assume also additional ham radio operators in Hawaii, Australia, New Zealand, etc. Also, 44 CONUS airport stations maintaining continuous listening watch on 3105 kHz.

Presumably, USS Colorado & USS Swan would have also been listening due to communication to that effect from COMHAWSEC.

The Post Loss Catalog seems to wrestle with this issue:  "Itasca’s failure to hear the dashes as clearly as Achilles implies a problem with Itasca’s antennas or receivers, which would account for Itasca’s consistent failure to clearly hear signals heard at other central Pacific stations and which should have been heard by Itasca. COMFRANDIV had cautioned Itasca about the possibility of such a problem on June 25. (MSG7.PDF, p. 260)"

Title: Re: Post loss Transmissions. Solved?
Post by: dave burrell on September 16, 2012, 03:05:42 PM
Jeff you seem to be arguing a point that was not a part of this thread. That being why Friedell searched to the south. He makes the point clear, repeating what tighar has stated 1000 times, to turn north on the lop would mean miles of open ocean.ect
Very little to do with radios.
Maybe after howland heard "distinct japanese music"on freq 3105khz on two seperate nights, and hawaiian radio was making pleas for AE to submit dashes he rightly thought this radio business had got out of hand with everyone with a radio set in on the act.
I can understand the Navy's skepticism of any radio transmission.

Title: Re: Post loss Transmissions. Solved?
Post by: pilotart on September 16, 2012, 06:19:41 PM
Those Colonist Radio Operators would have been aware that there was a High Frequency Direction Finding Receiver installed on Howland Island along with the other Pacific HF/DF Stations.

This would mean that their possible bogus transmission pretending to be Amelia Earhart could very likely be pinpointed to their location.

I would expect that the Criminal Penalty for such a Transmission would go way beyond just an FCC penalty for an illegal frequency violation.

Why take such a chance?

(I can understand the skepticism of any radio transmission by anyone who puts their faith in a 'Crashed & Sank' hypothesis.)
Title: Re: Post loss Transmissions. Solved?
Post by: dave burrell on September 17, 2012, 01:42:25 AM
Art you bring up the point of why would these kids chance it. ( and btw Jeff take a look at the pictures, these were kids).
Well why does a volunteer fireman set a fire and then call it in, risking his family and everything he worked for including possible jail time?
Because some people want to do it, simple as that.
To be a hero, to keep the action going, for a lot of different personal reasons.
However, to get into the minds of possible hoaxer, is way beyond our scope 75 years later. Was it malicious, or a joke a student played keying the mic a few times on a bathroom break....Did an operator accidently tie down the mic with a rubber band for two hours somehow after knocking it to the floor.. the possibilities are endless.
Who knows. We cannot know.
Since we cannot know, I am not stating it is a 100% fact there was a hoaxer. I am stating it is possible.

In that mass confusion of reports,  I have read or heard nothing that makes me buy into Brandeburg's summary report statement- " no central pacific ground station transmits on 278 kz or received on 3105 kz.
Therefore other the Itasca, Earharts electra was the only plausible source."

Partially Paraphrased, but that is what he basically said, and it leaves a lot of people saying WOW!... If a signal was picked up on 3105khz, then Brandenburg says it probably might have been Amelia, and she had to have landed, and so on.
When few know that these same land operators were indeed receiving on 3105khz, and possibly transmitting as well, and also reporting Japanese music being played over these same frequencies. I doubt Amelia was spinning Japanese records on Gardner Island in her spare time.
So, if some transmissions on 3105khz are in doubt, all are in doubt, and If Brandenburg is unaware of the capabilities of the Land sets, and/or never considered the probability of hoax transmissions, then the report itself is inconclusive in my opinion. If he found no documented conflict, it was a credible source.That ignores the possibility of hoax entirely, whether by the islanders or by vessel. But the bottom line is undeniable- there was obvious radio traffic documented on 3105khz other than what could have come from the electra or the Itasca. Take that into consideration when considering the post loss report summation.

Now I still believe she may have landed at Gardner. It is logical. The navy thought it logical. I simply put no faith in these so called post loss transmissions the more intently they are examined. Alan Harris called it right, something is wrong, it's fishy. This supposedly qualified operator calls the Itasca and tells them he hears Earhart distinctly. It was her!  Yet nobody else hears it, or seemed to put credence behind it(maybe they knew more about his personality than we do now).
Then, after what should have been one of the most memorable events in his life, certainly his closet brush with fame and history, Mr.Yum is interviewed and disavows ever knowing one thing about any post loss transmissions.
Now you can think that sounds like a credible, responsible person.
To me it sounds unbelievable. And that is just one operator. There were what, 3 operators on each island? And 12 or so Hawaiian students who operated the radios before as well. So a lot of possibilities exist.
I'll stick with the Navy's determination on this issue, there were a lot of transmissions to AE, a lot of confusion and cross talk, and not one solid transmission received that can be 100% tied to her, and her alone exclusively.

Now some will claim Navy conspiracy. If all else fails, that always seems to be the answer. I do not think so. The Navy did their job.
Let the Gardner landing evidence stand or fall on the real evidence, not radio waves carrying Japanese music and static, and bogus transmissions heard or perhaps even produced by teenage boys or a Japanese Fishing trawler.
The more the post loss transmission evidence is examined, the stronger I believe the Navy got it right in 1937.
Title: Re: Post loss Transmissions. Solved?
Post by: Gary LaPook on September 17, 2012, 10:22:03 AM

Interesting.  So again we have another situation where something is theoretically possible, assuming somebody wanted to go through the time and effort. but not necessarily likely nor even logically motivated given the actual prevailing circumstances at the time.  So assuming this is all correct, and I do find this information new to me and quite fascinating, I then have to ask: what would be their reason for making such a non-trivial modification to be able to transmit on an aircraft frequency?  How long would it take, would the materials for same be readily available on an island isolated from supplies, and would it inhibit their ability to use the radio as it normally would be used?  Also, would they be able to easily determine whether they were tuned correctly after such modifications were made, and whether they had tuned it properly back?

Not snark; honestly want to know.  I have no idea, these are just the questions that instantly pop into my mind when this kind of scenario is raised.  This does sound to me like another one of those things that could theoretically have happened but are a stretch in the real world but I don't have the HAM technical knowledge to know just how simple this would be (unlike the earlier suggestion that post-loss broadcasts could have been easily assembled with Amelia's voice from newsreels and such using technology at the time, which working in sound as I do, I know is not the case) so Gary, I do defer to you on that score...interested to hear more.
It was not "a non-trivial modification" it would have been trivial and it may not have required any modification whatsoever. Hams are not restricted to transmitting on any particular frequency but have bands in which a ham can choose any frequency he wants. The nearest band was the "80 meter band" which runs from 3500 to 4000 kcs. It is quite likely that the hams on the islands had a transmitter that covered the 80 meter band. However, depending on just how the transmitter was designed, the tuning range might have been larger and, for example, might have been tunable from, say 3000 to 4500 kcs. If so then all they had to do was to turn the dial down to 3105, no modification necessary.

If the radio didn't tune that low then the modification necessary was to simply change the point on the "tuning coil" where the "tap" was attached. O.K. a little (very little) technical discussion. Every ham knows the formula that determines the radio frequency:


frequency = 1/ (2 pi (square root of LC)) see http://www.zen22142.zen.co.uk/Theory/tunedcct.htm

"C" is capacitance and is set by a variable capacitor. "L" is the inductance and is determined by the size of the tuning coil. In the photo I posted before, the variable capacitor is in the front connected to the dial and the coil is, well, the coil.

Without doing the actual math, it should be clear (to those who didn't fall asleep in their algebra class) that if you increase either "L" or "C" or both, that the radio will be tuned to a lower frequency. The tuning range is determined by the range of adjustment of the variable capacitor, turning the tuning knob changes the capacitance smoothly from some low value to some high value and this is exactly what was happening when you turned the dial on your old AM receiver. When the dial was set to 500 kcs the variable capacitor was at its maximum position and when you turned the dial up to 1500 kcs then the variable capacitor was at its minimum position. The tuning range was 1000 kcs, from 500 to 1500 kcs, the AM broadcast band. This, in conjunction with a fixed coil, determined the band being covered. So if the hams' radios had a variable capacitor with a large range of values then the transmitter might have been tunable down to 3105 without making any change to the coil.

The amount of inductance from the coil is determined by how many turns there is in the coil. When building a radio you make the coil bigger than you think will be necessary and then select the actual number of turns by trial and error by placing a "tap" on the coil which determines the effective number of turns. I have attached another photo of a simple radio and you can see the coil and the "tap" points where the yellow wire with the "alligator clips" (you can probably guess why they are called "alligator" clips) on the end can be connected. To lower the band covered by this radio you simply move the alligator clip to a point further along the coil which makes more of the coil active. The coil in this picture was made with insulated wire so specific tap points had to be provided but with coils made out of bare copper wire (as in the first picture) then you can connect the alligator clip anywhere you want on the coil. Since radio coils are made with an excess of coils to allow for adjusting the band, then the island hams only had to move the tap out towards the end of the coil to move the transmitter down to 3105, no materials necessary and would take about five minutes.

To determine that they were on 3105 they only had tune in the Itasca on their receiver and then put out a very weak signal with their transmitter and turn the variable capacitor tuning knob to slowly change the output frequency of the transmitter until this weak signal was heard on the receiver already set to 3105.

gl


Title: Re: Post loss Transmissions. Solved?
Post by: Jeff Carter on September 17, 2012, 07:47:24 PM
I won't speculate on the weight of the gorilla, or the action of any of the Howland/Baker colonists.

But to Gary's point, a number of the Post Loss Transmissions were deemed credible in large part because "Earhart was the only plausible source of voice signals on 3105 kHz in the central Pacific."   If ham radio operators on the islands,  Australia, New Zealand, and Hawaii could easily modify their ham equipment to transmit on 3105, this assumption may need to be revisited.

A lot of the transmissions rated credible do not require a deliberate hoaxer, because the transmissions were too short, faint, or noisy.  Almost any transmission on the proper frequency would fit the reported transmission, i.e., an amateur operator could be testing their equipment, trying to help by calling KHAQQ, trying to respond to a message they thought they heard, inadvertently pressing the transmit key, or simply fooling around.     

For example http://tighar.org/Projects/Earhart/Archives/Research/ResearchPapers/Brandenburg/signalcatalog3.html --  40834PU, "Immediately following the KGU broadcast at 0833Z, the Pan American station at Mokapu heard a faint carrier on approximately 3105 kHz, but the signal was too weak to distinguish any words." or 41215WD  -- "Wake heard an intermittent male voice, of “rather wobbly characteristics.” Atmospheric noise prevented understanding what was said. At 1210Z, Wake heard several unreadable voice signals near 3105 kHz, in noise."

Title: Re: Post loss Transmissions. Solved?
Post by: Alan Harris on September 17, 2012, 09:49:29 PM
A lot of the transmissions rated credible do not require a deliberate hoaxer, because the transmissions were too short, faint, or noisy.  Almost any transmission on the proper frequency would fit the reported transmission . . .

For some reason, possibly my ignorance, it bothers me that the Howland radiomen repeatedly reported (http://tighar.org/Projects/Earhart/Archives/Documents/Logs/HowlandRadioLog.pdf) hearing Japanese broadcasts and music on 3105 KHz.  How much weaker would those signals have to be before fitting into the short/faint/noisy category?  (Of course foreign entities were not concerned with the FCC rules, that's not the part that bothers me; it's just that stuff like that was in the air on that frequency.) 
Title: Re: Post loss Transmissions. Solved?
Post by: john a delsing on September 17, 2012, 10:54:46 PM
Amelia stopped broadcasting after her “ we are running 158/337 line “. Many of us have been led to believe her radio broke and when she landed at gardner, she fixed her radio and started broadcasting again.  Is it not possible then, note I said possible, not probable, that Amelia never did fix  her radio, where ever she landed ( or splashed ) and all, yes all post loss transitions could have come from others transmitters in the Phoenix chain ?
Title: Re: Post loss Transmissions. Solved?
Post by: Gary LaPook on September 18, 2012, 12:25:53 AM

For example http://tighar.org/Projects/Earhart/Archives/Research/ResearchPapers/Brandenburg/signalcatalog3.html --  40834PU, "Immediately following the KGU broadcast at 0833Z, the Pan American station at Mokapu heard a faint carrier on approximately 3105 kHz, but the signal was too weak to distinguish any words." or 41215WD  -- "Wake heard an intermittent male voice, of “rather wobbly characteristics.” Atmospheric noise prevented understanding what was said. At 1210Z, Wake heard several unreadable voice signals near 3105 kHz, in noise."
There are quite few of the "credible messages" that were heard on frequencies near 3105, not exactly on it. These messages are more likely to have been from a source other than Earhart's radio since her's was crystal controlled and should be exactly on 3105, not just near it. The verified in flight messages from her in the Itasca log were on 3105 kcs so there is no reason that her transmitter's frequency would have changed to something just "near" 3105 kcs later on. But signals "near" 3105 are more likely to have come from a tunable transmitter, not a crystal controlled one, like a modified ham transmitter.

gl
Title: Re: Post loss Transmissions. Solved?
Post by: Adam Marsland on September 18, 2012, 01:34:41 AM
Thanks Gary for the posts.  Enlightening.  Still not sure why anyone would bother, but I think it's definitely worth keeping in mind in case some other corroborating evidence turns up.  One other thing that occurs to me -- weren't those islands significantly closer to the receiving stations than Gardner?  Would it make sense that such transmissions were unreadable in that case?  Again -- just raising the question for debate, not putting any real weight behind it.

And, of course, there's the issue of the bearings, which I tend to hang my hat on a lot more than any other piece of evidence (and the correlation of alleged post-loss transmissions with the tide being low on Gardner is also pretty compelling).  But that's fine...I think this is a really good question to be raised.  I for one was not aware there were other radios floating around.

Interesting point, too, about off-band transmissions.  I think that might have been addressed elsewhere, but it's an intriguing theory.  As I've said before, if the TIGHAR hypothesis is NOT correct (and regardless of how I or someone else might feel about it, there's an objective truth about what happened -- it either is or it isn't), there's a lot of odd little bits of evidence that have yet to be convincingly explained in a better way.  If TIGHAR is wrong, then the answers to those questions (who was the castaway?  How did Betty's Notebook come to be?  What was the 281 message? etc.) would be just as fascinating, and be the result of a probable combination of circumstances even more bizarre than the TIGHAR hypothesis.
Title: Re: Post loss Transmissions. Solved?
Post by: Gary LaPook on September 18, 2012, 03:30:27 AM

And, of course, there's the issue of the bearings, which I tend to hang my hat on a lot more than any other piece of evidence (and the correlation of alleged post-loss transmissions with the tide being low on Gardner is also pretty compelling).  But that's fine...I think this is a really good question to be raised.  I for one was not aware there were other radios floating around.


Before you accept the idea that the bearings eliminate the possibility of the transmissions coming from the hams on the islands, look at the attached chart. The green lines delineate the bearing range (+/- 10°) from Hawaii; the purple lines, the same from Wake; the red lines, the same from Midway; and the yellow lines the larger area (+/- 21.25°) from Howland. You will see that all the bearing ranges  include Baker so all of the bearings could have been taken on transmissions from Baker. (I know it looks silly to use the quarter of a degree level of precision but I did that to be consistent with my prior posts. The bearing errors could actually be many degrees greater than the 10° and 21.25° encompassed on the chart.)
 gl
Title: Re: Post loss Transmissions. Solved?
Post by: dave burrell on September 18, 2012, 04:33:21 AM
So you don't 'buy it' Dave.  That's not a '200 pound gorilla'.  You're still going on about why something just must be a certain way that you feel it should - and continue to offer no specifics.

That amounts to zip.

Same is true for your own possibilities for frequency tinkering, Gary - who cares what they might have done?  Other than what they 'might' have done, what can you show about what they were up to? 

Go into all that oral history and show us one firm example of where the kids were apparently busy tinkering out there to tweak their sets to go about this sinister task and this would get far more interesting.  Until that happens, all this '800 pound gorilla' talk and notions of kids wanking around with amateur sets to ghost for AE amount to nothing but strawmen - there's far less substance in these arguments than the ones you wish to challenge. 

Until there is more substance here to support these phantom transmissions there is no challenge here, just circular speculation.

LTM -

Jeff, you can't have it both ways. Tighars theory is speculation and "what ifs" and "would have dones" with bits of tantalizing evidence.
 
Amelia "would have" turned south
Amelia would have conserved fuel to make it to Gardner
Amelia would have landed on the reef
Amelia would not beach her plane
Amelia might not have had water to live a week
Fred might have a head injury
Amelia might have been inland when the search planes flew over
static received 1000 miles away was close to 3105khz so it must be her
The voices heard 6000 miles away might have been AE and Fred if the planets aligned just right, the ozone layer was just right, and AE was calling George about her suitcase. My favorite by the way.
A keyed mic left on for 2 hours was AE's carrier wave so maybe she tied down the microphone while wading back and forth to the plane.
The plane was not there a week later so it "might" have washed off the reef.

This speculation happens all the time. But that's ok as long as it fits the Gardner theory right? We can speculate without evidence as long as it fits her landing on a reef and calling for help.

Now if someone else comes up with an alternative to these transmissions,with evidence that points to either an accidental or intentional hoaxer then you throw it out as hogwash, and with a wave of the hand, saying "it's all speculation."

Yes, I agree. I wasn't there. Neither were you. I am connecting the dots. We do a lot of speculating.But I am not just throwing out Hockey pucks. Per Gary's analysis, all the bearings of these post loss transmissions could have come from Baker island. Fact. Per the documented logs, there were transmissions coming over on 3105 that were neither from AE or the Itasca. Fact. Per the documented logs, at least one Island operator has a memory of the events that does not match written reports. Fact.

As far as finding firm evidence the land Ham operators were "tinkering" or sending out potentially misleading transmissions, I rather doubt they took photographs of themselves doing it, if sending the US Navy on a wild goose chase. Let's be serious. If you demand that kind of evidence then just have another glass of tea and dismiss all this talk, because that is never going to happen. If someone by accident, or intent, mislead the Navy, he isn't going to confess or leave a written account of doing it.

But if you want the most conclusive evidence that the Brandenburg report was flawed, here you go once again- It was summarized that there were no other possibilites for these post loss signals on 3105KHZ but the Itasca or AE. Yet, we have Japanese Music being played on that same frequency. There is your specific. That proves the brandenburg conclusion is incorrect. http://tighar.org/Projects/Earhart/Archives/Research/ResearchPapers/Brandenburg/signalcatalog.html

 http://tighar.org/Projects/Earhart/Archives/Documents/Logs/HowlandRadioLog.pdf
 
There was indeed at least one other source, maybe several, for these post loss transmissions. None of them need come from the electra.
Where did it come from? Well Baker Island Triangulates very nicely, but that is just speculating. :)
The point is, I found specific examples which PROVE an alternative source besides Earhart. Which proves Brandenburgs summary was flawed. Which means the Post loss transmissions may not be evidence for a reef landing.
If you want to say that is "zilch", to each his own.
Title: Re: Post loss Transmissions. Solved?
Post by: dave burrell on September 18, 2012, 05:20:33 AM
Japanese Music Jeff. There is your substance.
Explain that and how it fits in with Brandenburgs report.
 http://tighar.org/Projects/Earhart/Archives/Documents/Logs/HowlandRadioLog.pdf

I see you have put the term "gorilla" in every one of your posts,
but let's talk about Japanese Music transmissions instead, on a frequency that supposedly only could have come from Amelia.
There is your substance.
If you don't want to bother with it, then ignore it of course.
Title: Re: Post loss Transmissions. Solved?
Post by: Bob Lanz on September 18, 2012, 06:55:26 AM
But if you want the most conclusive evidence that the Brandenburg report was flawed, here you go once again- It was summarized that there were no other possibilites for these post loss signals on 3105KHZ but the Itasca or AE. Yet, we have Japanese Music being played on that same frequency. There is your specific. That proves the brandenburg conclusion is incorrect.


Please post a link to the highlighted summary.



Title: Re: Post loss Transmissions. Solved?
Post by: Martin X. Moleski, SJ on September 18, 2012, 07:15:20 AM
Amelia stopped broadcasting after her “ we are running 158/337 line “. ...

That has not been established.

She was not heard after that last transmission.

Your assumption is: "If she had been transmitting, she would have been heard."

From that assumption, you reason, "She was not heard; therefore, she must not have been transmitting."

But the whole reason for having both daytime and nighttime frequencies (http://tighar.org/wiki/Frequency#Daytime.2Fnighttime_frequencies) was that the ionosphere affects reception (http://tighar.org/wiki/Radio_propagation).

She said she was changing to her daytime frequency (6210 kcs).  It seems very likely to me that she did what she said she was going to do.  Radios don't always work the way we expect them to.  Skip happens.  Close signals can fail to be heard; distant signals can be received.

She said they were "on the line 157 337.  ... We are running on line N and S."  It seems very likely to me that they were doing what she said they were doing.
Title: Re: Post loss Transmissions. Solved?
Post by: Jeff Carter on September 18, 2012, 03:21:11 PM
For those interested, Bob Brandenburg discusses some additional possible signal sources in:

Analysis of Radio Direction Finder Bearings in the Search for Amelia Earhart
http://tighar.org/Projects/Earhart/Archives/Research/ResearchPapers/Brandenburg/RDFResearch/RDFAnalysis/RDFpaper.htm

Title: Re: Post loss Transmissions. Solved?
Post by: dave burrell on September 18, 2012, 03:55:41 PM
Jeff, I am sure a lot of things are Well known to Tighar and by yourself.
I am sure Ric, and others have forgotten more than I ever care to know.
In no way am I the expert here, nor believe I am covering much new ground.

I do believe there are legitimate concerns with the Brandenburg conclusions given this Jacobson information and the Howland logs,  of not only Japanese Radio but Russian transmissions as well.

There are also areas I can find no information,for instance radios on Baker island. It's like a black hole. No logs, no background investigation of the operators, no exploring whether they had the capability to transmit a hoax. That started my questioning the boys school graduates. Bradenburg goes into how hard it would be to do a hoax on the US mainland, but argues against a localized hoaxer primarily due to logistics. Which really doesn't apply if the radio set is already on site. Now while it may not have been his job to address hoaxers, he started it, then I would expect him to finish it and address Japanese fisherman, Islanders, students, none of which he did. Just a cursory note that the logistics would be hard so for that reason it's implausible. The hoax angle got short attention.

The main problem with Bradenburg, as stated several times, is his conclusion that if something was received on 3105khz  it was most plausible the Itasca or the Electra( I have posted the reference 3 times in this thread alone, if you need it again let me know).Well clearly that is not true. He made a great report showing a count of Russian airplanes, reporting on if Wyoming could receive a transmission, and loads of technical details. Report after report he made. Great stuff.
Except for Japanese radio on 3105 totally destroying any faith we can have on those signals, that was ignored.

In digging deeper I find that not only were there operator logs showing contact with AE on howland(again linked on this thread), that these were not examined by Bradenburg. This study was done for Tighar correct?
Yet none of the land based data of transmissions was examined for a hoax.
Further I find that the Howland log shows Japanese radio on Amelia's Frequency, and now you are saying that Russian radio was heard as well.

So what do I wish for you to do with all this inconsistency? Not a thing. I am sure Tighar knows all about these issues. For me, it is a glaring problem in trusting any post loss transmissions. For you, maybe it is minor details.

This thread is probably geared for others like myself, reading the Bradenburg report and coming away with the impression that all transmissions coming in on 3105khz were AE. I used to believe that. When in fact we have no idea of the Japanese aircraft operating on those days, or the Japanese fishing vessels, and we have clear knowledge of Howland picking up radio signals clearly not AE's on her frequency. Brandenburg counted Russian aircraft. He didn't count Japanese aircraft or fisherman. Maybe that was impossible to count. Then SAY THAT! Say this report is incomplete due to unknowns.

Which in my simple mind, would naturally lead to the conclusion that Bradenburg was wrong(i.e. that all signals received on 3105 were likely AE or the Itasca.). It's too definitive given all the unknown variables.
Call me crazy. That point seems obvious. You have Japanese radio on 3105, then I cannot believe a scratchy transmission of a couple seconds on 3105 has to be Earhart. Common sense.

So instead of asking me over and over for the "evidence", I suggest you know the evidence. You said as much. I am telling you nothing you did not already know apparently. If you know all the evidence you know it doesn't always Jibe with AE doing the transmitting.
Therefore how can a newbie getting started on the gardner theory, trust any of these transmissions? Do we believe the logs, or do we believe Brandenburg? Do we believe Tighar, or do we believe the Navy?
That was rhetorical, your stance is already known.

I would like to ask a question myself since I have spent considerable time explaining my theories to you. If I may of course.
How you reconcile the reports of Japanese signals and Russian signals on the 3105khz frequency with the Bradenburg conclusions? How can you deny Brandenburg was wrong?
How can you trust any voice, dash, or continuous carrier wave, received when so much evidence points out multiple sources for these received transmissions? How can you be sure a Japanese fishing captain wasn't listening to his favorite channel out night trawling, and keyed his mic a few times? I don't see how anyone rational could eliminate these other sources since Japanese music was heard playing.
How can you put faith in these post loss transmissions?
Title: Re: Post loss Transmissions. Solved?
Post by: Adam Marsland on September 19, 2012, 02:39:24 AM

And, of course, there's the issue of the bearings, which I tend to hang my hat on a lot more than any other piece of evidence (and the correlation of alleged post-loss transmissions with the tide being low on Gardner is also pretty compelling).  But that's fine...I think this is a really good question to be raised.  I for one was not aware there were other radios floating around.


Before you accept the idea that the bearings eliminate the possibility of the transmissions coming from the hams on the islands, look at the attached chart. The green lines delineate the bearing range (+/- 10°) from Hawaii; the purple lines, the same from Wake; the red lines, the same from Midway; and the yellow lines the larger area (+/- 21.25°) from Howland. You will see that all the bearing ranges  include Baker so all of the bearings could have been taken on transmissions from Baker. (I know it looks silly to use the quarter of a degree level of precision but I did that to be consistent with my prior posts. The bearing errors could actually be many degrees greater than the 10° and 21.25° encompassed on the chart.)
 gl

Point taken, Gary, and it's a fair one.

We should not lose sight however, of evaluating probabilities:  is it more likely that the signals came from hoaxers/kids messing around on Baker, or a crash-landed plane on Nikumaroro?  The former is definitely the case if one is determined that they do not believe the latter took place.  But I do question, even if all other evidence is disregarded, that objectively you can say the former is a more likely explanation.  Plausible, perhaps.  But not necessarily more probable.

I think (though I am not one of them, just a someone fascinated by the research) TIGHAR acknowledges that "extraordinary claims require extraordinary proof"; however, the fact that people are skeptical that TIGHAR has the right answer might tend to make people bend over backwards to look for alternative explanations that only seem more plausible because people think the AE hypothesis is far-fetched; but on an objective scale, the alternate explanation is not really more likely.  It's just more mundane, and so seems more likely.

I'm not dismissing out of hand what's been brought up here.  I think it's a good kind of criticism, something that brings constructive new information to the table, and I am in favor of it.  It's just added perspective.  Ahem -- a dash of skepticism for the skeptic, if you will.
Title: Re: Post loss Transmissions. Solved?
Post by: Jeff Carter on September 19, 2012, 01:11:13 PM
Mixing the Ham Receivers (generally amateurs, with results reported second-hand via press reports) and the Pacific Receivers (generally professionals, with more thorough surviving documentation) tends to obscure how tenuous the Pacific receptions were.

Omitting HAM receivers for the moment, of the 47 Pacific sources rated credible by the Post-Loss Catalog:


The remaining 10 HAM receptions rated credible are the exact opposite -- 9 out of 10 reported a woman's voice and one is unclear whether the voice was male or female.  All voice, no HAM reports rated credible reported Morse or dashes.


Title: Re: Post loss Transmissions. Solved?
Post by: Gary LaPook on September 20, 2012, 03:06:38 AM
Since the local time at the site of the receiver is important in evaluating the radio propagation so be aware that there are some errors in the local time in the data base. All the Wake and all the Midway reports have the wrong local time. There is also an error in message #84 at Makapuu too.

gl
Title: Re: Post loss Transmissions. Solved?
Post by: Martin X. Moleski, SJ on September 20, 2012, 06:39:09 AM
Since the local time at the site of the receiver is important in evaluating the radio propagation so be aware that there are some errors in the local time in the data base. All the Wake and all the Midway reports have the wrong local time. There is also an error in message #84 at Makapuu too.

If you make up a list of corrections, I'm moderately confident that Ric and Bob will fix the database.
Title: Re: Post loss Transmissions. Solved?
Post by: Gary LaPook on September 20, 2012, 02:53:26 PM
Since the local time at the site of the receiver is important in evaluating the radio propagation so be aware that there are some errors in the local time in the data base. All the Wake and all the Midway reports have the wrong local time. There is also an error in message #84 at Makapuu too.

If you make up a list of corrections, I'm moderately confident that Ric and Bob will fix the database.

These assume that the ZULU times are correct.

83
Identifier    41512PY
Z Time/Date    1512 July 4
Local Time/Date    1512 GCT July 4 0312 July 4
Gardner Time/Date    0412 July 4

----------------------------------------------------

85
Identifier    41553PY
Z Time/Date    1553 July 4
Local Time/Date    1553 GCT July 4 0353 July 4
Gardner Time/Date    0453 July 4

----------------------------------------------
102
Identifier    50638PY
Z Time/Date    0638 July 5
Local Time/Date    0638 July 5 1838 July 4
Gardner Time/Date    1938 July 4

---------------------------------

77
Identifier    41215WD
Z Time/Date    1215 July 4
Local Time/Date    1215Z July 4        2315 July 4
Gardner Time/Date    0115 July 4
----------------------------------------
121
Identifier    50948WD
Z Time/Date    0948-0952 July 5
Local Time/Date    0948-0952 Z July 5       2048-2052 July 5
Gardner Time/Date    2248-2252 July 4
------------------------------------------
129
Identifier    51223WD
Z Time/Date    1223-1236 July 5
Local Time/Date    1223-1236 Z July 5      2323-2336 July 5
Gardner Time/Date    0123-0136 July 5
---------------------------------------
84
Identifier    41523PU
Z Time/Date    1523-1530 July 4
Local Time/Date    0453-1600 July 4 0453- 0500 July 4
Gardner Time/Date    0423-0430 July 4



gl
Title: Re: Post loss Transmissions. Solved?
Post by: Martin X. Moleski, SJ on September 20, 2012, 03:22:46 PM
These assume that the ZULU times are correct.

Thanks, Gary.  I see the problem.
Title: Re: Post loss Transmissions. Solved?
Post by: Jeff Victor Hayden on September 20, 2012, 03:43:12 PM
Didn't the credibility factor of some of these transmissions depend on the low and high tides at Gardner on the dates and times concerned?
How do the teenage hoaxers fit in with these tide dates and times?
Coincidental exact match or random?
Or am I talking a load of bull#*#t ?
Title: Re: Post loss Transmissions. Solved?
Post by: Gary LaPook on September 20, 2012, 03:53:56 PM
Didn't the credibility factor of some of these transmissions depend on the low and high tides at Gardner on the dates and times concerned?
How do the teenage hoaxers fit in with these tide dates and times?
Coincidental exact match or random?
Or am I talking a load of bull#*#t ?
At the symposium, Ric put up a graphic showing the state of the tide in relationship to the messages. Has Ric put that graphic up somewhere on the website, I couldn't find it? That would answer these types of questions.

gl
Title: Re: Post loss Transmissions. Solved?
Post by: pilotart on September 20, 2012, 04:35:00 PM
Just how would a Hawaiian/Chinese ethnic America teenage boy sound imitating a lady from Kansas?

I believe the Island Colonist's Transmitter was code only, no voice possible.  I read on the forum archive that they had a hand cranked 400 Volt Generator (from the Army) which must have been for their transmitter.

I think that their Battery powered receiver would receive voice as well, wonder how they charged their batteries?

From Ric: (http://tighar.org/smf/index.php/topic,509.msg6491.html#msg6491)
Quote
November 07, 2011
We have a set of tide charts for the reef from July 2 to July 9 with the credible post loss signals overlaid. We're presently coding them up for publication on the TIGHAR website.  Get a good grip on your socks.

Earhart Project Research Paper
August 15, 2006 (http://tighar.org/Projects/Earhart/Archives/Research/ResearchPapers/Brandenburg/TidalStudy/PLSigStatsandTide.pdf) does show the tide level for each Transmission.
Title: Re: Post loss Transmissions. Solved?
Post by: pilotart on September 20, 2012, 04:41:35 PM
Lazy question!

How many post loss transmitions were code/key as opposed to voice?

http://tighar.org/smf/index.php/topic,944.msg19870.html#msg19870 (http://tighar.org/smf/index.php/topic,944.msg19870.html#msg19870)
Title: Re: Post loss Transmissions. Solved?
Post by: Jeff Victor Hayden on September 20, 2012, 04:59:58 PM
Thanks for the link Pilot and Jeff, I'll browse through 2moro to see if it sheds any light on this debate.
Title: Re: Post loss Transmissions. Solved?
Post by: Gary LaPook on September 20, 2012, 06:21:44 PM
Didn't the credibility factor of some of these transmissions depend on the low and high tides at Gardner on the dates and times concerned?
How do the teenage hoaxers fit in with these tide dates and times?
Coincidental exact match or random?
Or am I talking a load of bull#*#t ?
At the symposium, Ric put up a graphic showing the state of the tide in relationship to the messages. Has Ric put that graphic up somewhere on the website, I couldn't find it? That would answer these types of questions.

gl

Good call, Jeff and Gary -

Here is a link where the tide tables can be found (http://tighar.org/Projects/Earhart/Archives/Research/ResearchPapers/Brandenburg/TidalStudy/TidalStudy.htm).
I've seen that but it is not the graphic that Ric put up at the symposium, you remember what it looked like Jeff?

gl
Title: Re: Post loss Transmissions. Solved?
Post by: dave burrell on September 20, 2012, 07:04:41 PM
Just how would a Hawaiian/Chinese ethnic America teenage boy sound imitating a lady from Kansas?

Well It has been established that at most we are referring to a word or two. How many times did Jeff count? two instances, 4 words received by Professional operators?

Nobody heard Amelia Earhart reciting the Gettysburg address or even saying "this is Amelia Earhart". Not even that much.

Given that dialects are very subjective to each ear, and given that we know there were new zealand boats within the transmission range,
and Russian signals within the transmission range,
and British boats within the transmission range,
and Two islands within the triangulation, with high school boys whose voices were probably not mature and gruff,
and most of all a japanese radio station playing the hits of the 30's, with perhaps Tokyo rose(yes I know that is a WWII reference but there could have been a woman DJ) spinning the platters,
and possibly multiple Japanese vessels fishing since this area was near a prime whaling ground(lets not forget one Japanese fishing boat helped offered to search, so they were out there in unknown numbers),
I think it's safe to say given these 4 words, there are a fairly large number of sources that they could have originated from. Hearing from one of those numerous sources, an excited operator could exclaim "we have her!" (with a weak signal no less, and couldn't understand a word said)..

So the voice evidence is scant to be kind, by any reasonable definition of a pronouncement of an emergency.

Same with the Code evidence. Take 31057, 22 dashes that Bradenburg said was plausible to only come from Earhart.
Well Dr.Bradenburg doesn't know how many Japanese Tuna and Whaling Boats were there testing their equipment either.

http://tighar.org/Projects/Earhart/Archives/Research/ResearchPapers/Brandenburg/signalcatalog2.html

Bottom line, the Navy said it best, a lot of people were sending stuff, and  different nationalities were just doing their jobs catching fish, and piloting their boats, and operating their Navy craft, and were receiving and possibly transmitting on 3105. The rest of the world didn't stop for Amelia Earhart. There was no full sentence heard by anyone outside the mainland US(determined to be hoaxes). Except for famous Betty of course in Florida. Well even she didn't hear a full sentence, but Leaving out Betty, Are you sure a young Japanese or Chinese boy, or woman japanese radio broadcaster wasn't the source of these precious few fragments of words? One weak and barely heard word spoken by a woman Japanese broadcaster from thousands of miles away might sound like Amelia to an overactive and excited mind.
Just saying.

http://tighar.org/Projects/Earhart/Archives/Research/ResearchPapers/Brandenburg/signalcatalog2.html
Title: Re: Post loss Transmissions. Solved?
Post by: Mark Pearce on September 20, 2012, 08:21:21 PM
Very well done Dave.

The 'Sydney Morning Herald' published an editorial  (http://news.google.com/newspapers?nid=1301&dat=19370710&id=4athAAAAIBAJ&sjid=C5UDAAAAIBAJ&pg=7184,1521350) on July 10, 1937 that touched on some of the same areas you have introduced here. 

[...and this Tasmanian newspaper (http://tighar.org/smf/index.php/topic,883.msg17584.html#msg17584) did the same on July 9, 1937]

FALSE CLUES.
MRS. PUTNAM'S PLIGHT.
A Psychological Study.
(BY A. PALMER.)

The disappearance of Mrs. Amelia Earhart Putnam, and her navigator, Captain F. J. Noonan, while flying across the Pacific from Lae (New Guinea) to Howland Island, and the subsequent deluge of false clues provided by amateur radio operators in various parts of the world, have provided psychologists with an interesting study in human reactions to disaster.

Immediately it was learned that Mrs. Putnam's 'plane had been forced down somewhere on the ocean within 100 miles of her destination, radio operators reported having received messages from the lost flier, giving her approximate position and describing her predicament. The reports were so conflicting, and in some cases so "realistic," that the officials were forced to conclude that they were either false or were the result of imagination on the part of those persons listening-in. This belief was strengthened when the Lockheed Company of America, manufacturers of Mrs. Putnam's machine, explained that if the airwoman had come down on the water it would be "utterly impossible for her to send out wireless calls." Only one conclusion remained, and that was that many of the radio operators who claimed to have heard messages were suffering from a "will to believe," and had imagined that they had been in touch with the lost flier.

NOTHING NEW.
This is no new phenomenon. It was amply demonstrated in New South Wales only a few months ago, when a search was being carried out for the Stinson monoplane of Airlines of Australia, which was subsequently found by Mr. Bernard O'Reilly in the Macpherson Ranges. On that occasion hundreds of messages were received by those conducting the search, and by the newspapers, from persons who had "heard the 'plane crash," saw it "flying south," or "burst into flames as it struck a hilltop," hundreds of miles from the scene of the disaster. A number of persons were convinced that they had seen it crash into the sea just north of Sydney. Many of the people who claimed to have seen the machine were reputable citizens, and were honest in their belief. How to account for their apparent certainty or awareness of something that did not exist will never be satisfactorily explained, unless it is described as a form of mental and optical illusion, conjured up by a hope that the persons in danger might be found safe- a form of self-hypnosis.

Many similar incidents can be found right through recorded history, and the writer has a vivid recollection of one of the most striking examples of how the mass mind can be influenced by this will to believe. The incident referred to occurred in London a few years ago. A prominent “'Plane Advertising Company” announced that it intended to carry out a height-judging competition for a well known London evening newspaper. An aero-plane was to fly over the city and the readers were to be asked to judge the height at which it passed overhead. The newspaper published beforehand full particulars, of the times and routes over the city which the company had contracted to fly. Substantial prizes were offered, and consequently public interest was keen.

NO 'PLANE UP.
The great day arrived, but, owing to a heavy rainstorm, and forecasts, of dangerous flying conditions, the 'plane did not leave the ground. Nevertheless, to the amazement of the advertising company, and those associated with the newspapers, hundreds of replies were sent in to the competition, by persons who "saw the plane flying over the city." In all seriousness they estimated the height at which it had flown at figures varying from 50 feet to 7000 feet, and gave the time at which it passed certain points. An exhaustive inquiry proved that no aeroplane had flown over the area at any time during the day.

Several remarkable letters have been preserved complaining of the danger to the public of machines being allowed to fly over congested cities at "such a low altitude." There seems to be no doubt that many of the messages alleged to have been received from Mrs. Putnam during the last week were the result of a similar form of self-hypnosis, inspired by a deep and sincere desire on the part of the radio operators concerned, working under high nervous tension, to do everything possible to rescue a brave flier from imminent peril.
Title: Re: Post loss Transmissions. Solved?
Post by: Martin X. Moleski, SJ on September 21, 2012, 07:27:00 AM
These assume that the ZULU times are correct.

83
Identifier    41512PY
Z Time/Date    1512 July 4
Local Time/Date    1512 GCT July 4 0312 July 4
Gardner Time/Date    0412 July 4

...

Bob says: "The Pan Am reports used GMT, and make no mention of local time, so we assume they used GMT as local time (catalog footnote 15).   We used GMT-11 for Gardner local time."

I don't know enough about the methodology of the catalog to say whether this is consistent with what they have done elsewhere.  If they are strictly recording the data in the "Local Time/Date" field, then it would be wrong for them to carry out a calculation to "fix" the record (the suggestion you have made in red).  1512 GCT (or GMT or UT or Z or whatever, more or less) seems to be what was in the record, and they have apparently correctly made the Z field identical to what is in the logs.

This is one of those things about which reasonable people may reasonably disagree.  When you do your own analysis, you may choose a different strategy than Ric and Bob have.
 
Title: Re: Post loss Transmissions. Solved?
Post by: Martin X. Moleski, SJ on September 21, 2012, 09:24:00 AM
OK, one last note from Bob:

"With one exception the local time entries for the Pan Am sites are correct.  The Pan Am reports use only GMT, and decisions about those signals do not depend on local zone time, so we adopted the convention of using GMT as local time for those sites.
 
"The exception is 41523PU, which incorrectly shows the local time as 0453-1600 July 4.  That should be 1523-1520 Z July 4.  We'll fix it.
 
"Gardner local time is computed as GMT-11, because we use Hull Island as the tide reference station for Niku tides, and the UK Hydrographic Office -- which provides tide hindcasts for Hull -- computes tides for GMT-11."
 
Title: Re: Post loss Transmissions. Solved?
Post by: Gary LaPook on September 21, 2012, 03:43:18 PM
OK, one last note from Bob:

"With one exception the local time entries for the Pan Am sites are correct.  The Pan Am reports use only GMT, and decisions about those signals do not depend on local zone time, so we adopted the convention of using GMT as local time for those sites.
 
"The exception is 41523PU, which incorrectly shows the local time as 0453-1600 July 4.  That should be 1523-1520 Z July 4.  We'll fix it.
 
"Gardner local time is computed as GMT-11, because we use Hull Island as the tide reference station for Niku tides, and the UK Hydrographic Office -- which provides tide hindcasts for Hull -- computes tides for GMT-11."
That is the strangest idea of "local time" that I have ever heard of and it must have been difficult for the personnel on Midway to have to eat lunch  at midnight as required by Brandenberg's clock saying that the middle of the night is twelve, noon local time. And the justification that they were just copying, without any changes, the logged time breaks down as they made up a time for the Gardner local time field calling it 11 hours behind Greenwich when it should be 12 hours behind Greenwich.

gl
Title: Re: Post loss Transmissions. Solved?
Post by: Martin X. Moleski, SJ on September 21, 2012, 05:09:49 PM
That is the strangest idea of "local time" that I have ever heard of and it must have been difficult for the personnel on Midway to have to eat lunch  at midnight as required by Brandenberg's clock saying that the middle of the night is twelve, noon local time. And the justification that they were just copying, without any changes, the logged time breaks down as they made up a time for the Gardner local time field calling it 11 hours behind Greenwich when it should be 12 hours behind Greenwich.

As I said, making a decision about how to report their findings is something about which reasonable people may reasonably disagree.

The fact that the radio logs were kept in Zulu says nothing about how other clocks were set on board the ship.

The reason for using 11 rather than 11.5 or 12 is that it makes it easy for them to work with their tide tables.  Having spent a couple of days working on the article on timezones (http://tighar.org/wiki/Timezones), I know the value of getting information into some kind of standard format.

Since they have explained the arbitrary choices they have made, anyone who wishes to treat the data differently may do so by making their own arbitrary choices.  So long as both of you apply your own methods consistently, all should be well.
Title: Re: Post loss Transmissions. Solved?
Post by: Gary LaPook on September 22, 2012, 01:21:51 AM
Another error in the data base:

118
Identifier    50916CS
Z Time/Date    0916 July 5
Local Time/Date    0116 July 5
Gardner Time/Date    2216 July 5     2216 July 4

gl
Title: Re: Post loss Transmissions. Solved?
Post by: dave burrell on September 24, 2012, 03:42:27 AM
One last point I missed during thread weave. I'll call it the howland of silence.
Quite catchy?.. ok maybe not. Anyhoo...

I started this thread to bring attention that the Islands at "ground zero" might be the most logical spot to look for where the transmissions were coming from. In Dr. Bradenburgs report (which is due proper respect,), a lot of transmissions were rated as "credible" in large part on the assumption that there was no other source possible for logistical reasons, that being no other radios transmitting on AE's frequency. Well I have shown there were radios in range able to complete the task. Two islands nearby and an unknown number of military and civilian boat traffic, as well as Japanese and Russian radio stations on 3105khz as well.(though of course Mainland Asia would not triangulate)

 Multiple stations using the 3105 frequency is a fact. So a fragment of speech, or a dash, could have come from any of those stations by intent or accident if in the right area.That is not speculation. Bradenburg considered Nicaraguan sources, but left off the Japanese military,boats, and Howland and Baker islands. What Japan had and where is unknown in 1937 and without that knowledge we cannot say with any degree of certainty any transmission is from the Electra.

Baker and Howland is where I started this hoax theory. Because they fit the triangulation area and had Ham sets. Japan is the huge variable because what they had and where it was at is the great unknown. One country alone could be the source of all these transmissions.

But I started at the Howland/Baker duo as the first possible alternative source, so I would like to clarify a point I was making on the islands; so back to the Ham operators and if they could pull off a hoax....
1. They had radios. They could listen and probably transmit to the required frequency. They had the means and opportunity with minor speculation.
2. Their actions were odd in hindsight. Motive? who knows. Excitement? Spite?
 Let's go back for a minute..
On day two of the loss, Baker finally chimes in and reports Amelia was heard BY VOICE. Not many voice transmissions were heard. What is odd is that it was reported from Baker to Howland to Itasca. It was listed as "delayed". So baker gets it, sends to his pal yum on Howland, who holds this information for another day, then sends it to Itasca. One of the very few voice transmissions from the electra, life and death, and it's delayed?  Now maybe there is a good reason for that, but I cannot think of one. That is a circumstantial event that can lead to the subjective opinion of accepting or rejecting the source.
http://tighar.org/Projects/Earhart/Archives/Research/ResearchPapers/Brandenburg/signalcatalog.html

But we also have something even more odd in my opinion going on with these two amateur stations on Howland and Baker. If you read the catalog, you will find most transmissions are picked up by the Itasca. Which makes sense, being as it was fairly close, say 400-600 miles from Niku? It was close. But Baker and Howland were even closer. The post loss catalog is a lot of Itasca hearing signals, but next to nothing from Baker and Howland.
Isn't that odd? Especially since it has been postulated that there were issues with the Itasca's recievers or attenna as a reason the Itasca could sometimes not hear a transmission a New Zeland or British Boat did hear. The Itasca may have not had tuned radios but the vast majority of transmissions were received by that old boat. A lot of fragments heard by the Itasca and her supposedy bad antenna or receivers. There was Amelia out night after night transmitting, too bad the only receiver within 500 miles had bad antenna right?.. well wrong.

We have the silence of Baker and Howland. How many did they receive? The closest radios. They both heard zilch as Amelia went further and further away from Howland to Gardner supposedly. They did not hear her frantic the first night after landing on a reef. Well we know of the one weird example just listed. The "delayed" transmission. I believe there was one other transmission received by these two islands.

Why?To speculate, the obvious answer is they were doing the transmitting.
The first "delayed" report Yum sent over after holding it a day might have been looked on with suspicion from the Itasca. They had not heard it. This young Chinese kid heard Amelia talking and the military had not?
Both of these two islands inactivity in this search, being the closet to Niku, is just weird. They were only 350 miles away. Lae heard Earhart 400 miles away. The Itasca was picking up signals all over it's search area. There were people in Toronto, Kentucky, getting Amelia hits. Not so much with the new Chinese operators at the scene of the crime so to speak. Not even a fragment on day 1. The theory of Baker being too close to hear,  may be theoretically feasible. I rather doubt it. That they were listening would seem  given the magnitude of the event and demands of the Navy.
Their logs prove they were receiving Japanese music on 3105khz.
But not a lot of Amelia activity after the one delayed report Yum turned in.
At the least, perhaps a study of the Ionosphere and propagation results could answer why Baker and Howland had so few receptions.

Just speculation? Yes and No.
No speculation in pointing out multiple sources for transmitting on the 3105 frequency. Baker and Howland were there. It is speculating that Howland , Baker, or the Japanese pulled a hoax, a transmission block, or innocent and accidental transmissions that were picked up in fragments and misinterpreted.

Yes a few possible transmissions triangulate close to Gardner. But there were other possibilites for each and every one of these transmissions besides Amelia.A boat searching for Tuna, or the Japanese wanting to check out our ships and response times, or it could be as simple as a disgruntled Chinese teenager on Howland/Baker.
They could all triangulate as well.
Title: Re: Post loss Transmissions. Solved?
Post by: dave burrell on September 24, 2012, 07:50:45 AM
Well maybe Disgruntled is a bad term. I would say disinterested until Black woke them up.
Here is Jacobson
http://tighar.org/Projects/Earhart/Archives/Research/JacobsonDatabase/RADIOLOG/RADREST.PDF
Reading this all you hear is Itasca, over and over calling every station.
Howland wasn't involved. Even with the Howland DR down, they didn't jump to the plate to help.
After a couple days go by Itasca issues urgent message to Howland from Black. " Keep listening to 3105, keep the "boys' (his term), UP, and ready."
The way he was referring to the amateurs at Howland and Baker did not seem like he had high regard for them. Read it how you wish.
Black seemed irritated by them and wanted their help.
 
It seems to me that Black himself was asking why Howland wasn't reporting anything.  Then and only then, does Howland begin to get involved. They do their delayed report of hearing Amelia,  Yum begins to report on a continous wave that apparently was nothing, "near 3105". Yum begins to answer Itasca. Before it appeared he ignored Itasca.
The first two days it seems like Howland was not even there. Itasca could never reach them.
Hell maybe Lum was asleep, at one point he asks Itasca can he go sleep.

Throughout all that Baker is silent, even after Black intervened. Itasca is asking about Baker through Howland and nothing is received. I didn't find one transmission to Itasca from Baker.

So it could be a couple of things.
1. They were asleep or surfing during the flight. With dead batteries. Only after the big shots got involved did they begin to answer the radio. They then did the best job they could. Unfortunate they were not listening sooner while Amelia flew to Gardner.
2.Or two, they were doing the best job they could all along, but wanted to stay out of the way. Very Young, and didn't feel it was their place. They never heard anything regardless.

Neither scenario one or two precludes Yum getting excited after the Black transmission and starting to "create" stuff. He begins to add transmissions as a hoaxer does to be even more involved, a hero, or self hypnotized, realizing this is big time.

Baker never got involved in any event that I can find. No record of Itasca talking to them. Or hearing from them but once.

So does yum or baker get creative? I don't know. Is it possible he got involved and started to key in some dashes? Lapook says it's easy, you say it's not proven they could transmit.
I think they could transmit, nothing I have read says a Ham set can only listen on 3105 but not transmit as well. Gary knows more than moi, so I'll go with Gary on that.

If it is possible, then that is all I was stating. The Brandenburg report says there was no other source possible. I am stating there was. It may have been right under our noses, and it was possible.

As far as the Japanese, I wasn't saying the Japanese were transmitting from mainland Japan. Of course that is outside the triangulation. I was saying we have no idea of the Vessels or where they were at or their frequencies. They are unaccounted for. People talking about it being against the Federal rules are missing the point. IT"S JAPAN GEARING FOR WAR.
They definitely used that frequency, and we cannot account for their vessels,(or for that matter their new fortifications on Islands unknown) then they cannot be eliminated as a source.
You cannot put out a huge research paper saying this is signal is credible because it came on 3105khz, because we in America only use 3105 for aircraft, therefore the only plane in the area is AE. That is crazy.

Hooven thought it possible the Japanese were involved blocking American signals, I'll go one step further. It's possible they made American signals to watch our response and ship movements.
Improbable? That is another issue. We are asking if it was possible.
If we want to talk improbable let's discuss Miss Paxton In Kentucky hearing Amelia...
It was not impossible for these signals on 3105khz to be totally unrelated to Earhart.
Title: Re: Post loss Transmissions. Solved?
Post by: Gary LaPook on September 26, 2012, 04:21:33 PM

I started this thread to bring attention that the Islands at "ground zero" might be the most logical spot to look for where the transmissions were coming from. In Dr. Bradenburgs report (which is due proper respect,), a lot of transmissions were rated as "credible" in large part on the assumption that there was no other source possible for logistical reasons, that being no other radios transmitting on AE's frequency. Well I have shown there were radios in range able to complete the task. Two islands nearby and an unknown number of military and civilian boat traffic, as well as Japanese and Russian radio stations on 3105khz as well.(though of course Mainland Asia would not triangulate)

 Multiple stations using the 3105 frequency is a fact. So a fragment of speech, or a dash, could have come from any of those stations by intent or accident if in the right area.That is not speculation. Bradenburg considered Nicaraguan sources, but left off the Japanese military,boats, and Howland and Baker islands. What Japan had and where is unknown in 1937 and without that knowledge we cannot say with any degree of certainty any transmission is from the Electra.


Their logs prove they were receiving Japanese music on 3105khz.

Just speculation? Yes and No.
No speculation in pointing out multiple sources for transmitting on the 3105 frequency. Baker and Howland were there. It is speculating that Howland , Baker, or the Japanese pulled a hoax, a transmission block, or innocent and accidental transmissions that were picked up in fragments and misinterpreted.

Yes a few possible transmissions triangulate close to Gardner. But there were other possibilites for each and every one of these transmissions besides Amelia.A boat searching for Tuna, or the Japanese wanting to check out our ships and response times, or it could be as simple as a disgruntled Chinese teenager on Howland/Baker.
They could all triangulate as well.
Mainland Asia does "triangulate," contrary to what you said, meaning that the bearing taken by Wake could well have been from a station located in China, Korea, Russia, or Japan, see attached chart. In fact, Japan is a couple of hundred miles closer to Wake than is Gardner. The Wake bearing could also have been from any station located anywhere within the ten degree bounded areas (or even larger areas, I am just using the plus and minus ten degree limits for convenience, larger areas are possible according to the official government publication that I posted before (https://tighar.org/smf/index.php?action=dlattach;topic=940.0;attach=4169)) from ships and islands, including Samoa, and Fiji is just outside the area. However, as I said before, you can not cross or "triangulate" bearings taken at different times and I am working on a detailed post to illustrate why that is the case.

gl
 
Title: Re: Post loss Transmissions. Solved?
Post by: Gary LaPook on October 12, 2012, 02:17:13 AM
Ah - yes, now you've jogged my memory, Gary - but I don't think I've seen it in the site here either.

Jeff, I have not been able to find the graphic that Ric had at the symposium showing the correlation of the radio reception reports with the tides at Gardner which makes this correlation very clear. I wish Ric would make it available to everyone on the forum since it would answer the questions that have been raised by several people. The graphic looks a lot like the file I have attached, which is  a graph that I have created from memory of what Ric's graphic looked like. Like on Ric's graphic, I have drawn  vertical lines representing the radio signals plotted against the local time on Gardner (Zulu minus 11 hours), these come from the TIGHAR data base so should accurately replicate the lines on Ric's graph. I don't have the tide data (it is not available on TIGHAR either) so I just freehanded in what I remember of Ric's graphic which shows that the radio signals were sent out when the tide was low at Gardner and only one was sent out when the tide was higher, which Ric said was done by using the battery.                                                                                 
                                                                                                                     
Take a look, does this graph match your recollection too?  Anybody else that saw Ric's graphic at the symposium see any glaring errors in my graph with the line showing the height of the tide just drawn in by hand to represent an approximation of the same line on Ric's graphic?

gl
Title: Re: Post loss Transmissions. Solved?
Post by: Jeff Carter on October 12, 2012, 10:47:30 AM
Here's a plot I made for my own interest.  AS IS.  No warranties or guarantees that I did all the conversions right in the Excel spreadsheet.  Colors are from the Post Loss report.   

http://tighar.org/Projects/Earhart/Archives/Research/ResearchPapers/Brandenburg/signalcatalog.html which says:
    Identifiers in BLUE are TRANSMISSIONS to Earhart.
    Identifiers in RED are reported receptions that are judged to be NOT CREDIBLE.
    Identifiers in BLACK are reported receptions the credibility of which are judged to be UNCERTAIN.
    Identifiers in GREEN are reported receptions that are judged to be CREDIBLE.

(http://i.imgur.com/NCXnH.jpg)
http://i.imgur.com/NCXnH.jpg

I think all it shows is that everyone was active listening in the morning Z-Time.

Title: Re: Post loss Transmissions. Solved?
Post by: Jeff Victor Hayden on October 12, 2012, 11:04:56 AM
Nice work with the graphs Gary and Jeff.
One point that sticks out like a sore thumb from Garys graph. If the hoaxers were indeed the source of the transmissions then it is one hell of a coincidence that they transmitted at Gardner island low tide nearly every time, why would they do that (was their transmitter in Bakers surf line) and, what are the odds of that being pure luck?
Title: Re: Post loss Transmissions. Solved?
Post by: Gary LaPook on October 12, 2012, 03:37:02 PM
Here's a plot I made for my own interest.  AS IS.  No warranties or guarantees that I did all the conversions right in the Excel spreadsheet.  Colors are from the Post Loss report.   

http://tighar.org/Projects/Earhart/Archives/Research/ResearchPapers/Brandenburg/signalcatalog.html which says:
    Identifiers in BLUE are TRANSMISSIONS to Earhart.
    Identifiers in RED are reported receptions that are judged to be NOT CREDIBLE.
    Identifiers in BLACK are reported receptions the credibility of which are judged to be UNCERTAIN.
    Identifiers in GREEN are reported receptions that are judged to be CREDIBLE.

(http://i.imgur.com/NCXnH.jpg)
http://i.imgur.com/NCXnH.jpg

I think all it shows is that everyone was active listening in the morning Z-Time.
That's a nice graph and it shows that the "not credible" transmissions do not fit the tide pattern and that a number of the "uncertain" ones do. Unfortunately it does not have the tide information that Ric's graphic had which makes this relationship much easier to see.

gl
Title: Re: Post loss Transmissions. Solved?
Post by: Doug Giese on November 15, 2012, 03:31:41 PM
Jeff Carter, Gary,

Here is Gary's tide chart overlaid on Jeff's radio traffic chart.

I'm pretty sure I got the Z time offset (I aligned t=1100 on the radio traffic chart with t=0000 on the tide chart) right since the radio intercepts matched up quite well between the two charts.

I know I've seen a TIGHAR chart like this. If the TIGHAR tide chart is located I can duplicate a chart like this with the TIGHAR data.

Edit: Ignore this attachment. I've found raw tidal information on Hull Island (tides offset from Niku by about 10 minutes) from two different sources. I posted a revised version using updated tides here (http://tighar.org/smf/index.php/topic,944.msg21663.html#msg21663).
Title: Re: Post loss Transmissions. Solved?
Post by: Alan Harris on November 15, 2012, 03:57:28 PM
Here is Gary's tide chart overlaid on Jeff's radio traffic chart.

I know I've seen a TIGHAR chart like this. If the TIGHAR tide chart is located I can duplicate a chart like this with the TIGHAR data.

Interesting idea, but I don't think Gary meant that to be a "real" tide chart, it was just an example of something or other.  For one thing, in reality there are 2 high tides and 2 low tides every 24 hours ("semi-diurnal").  I don't think we've seen current TIGHAR charts for the whole period.  There was one shown recently for 9 July, and IIRC 2 and 3 July (GMT) were posted a longer while ago.
Title: Re: Post loss Transmissions. Solved?
Post by: Doug Giese on November 15, 2012, 05:14:41 PM
Alan,  yes. I had some time and thought I'd overlay the loss chart onto the tide tables. I had intended to use the tide tables I know I've seen somewhere but couldn't find them quickly so used Gary's tide tables knowing when the real ones turned up it would only take a few minutes to update the Photoshop file.

Title: Re: Post loss Transmissions. Solved?
Post by: Joe Cerniglia on November 15, 2012, 07:31:15 PM
Here is something I thought might be of interest for building overlay plots, or for casual interest in viewing the radio messages reported to have been heard on July 2, 1937 and the days afterward.  A year ago, I transcribed all the post-loss signal data to an Excel spreadsheet. The spreadsheet provides an easy way to group data by category of hearer, time of day, credibility assessment, frequency, and others.  You can also see many of the signals at a glance to compare and contrast.  Use the arrow at the top of the "Record Link" field to group related subjects (e.g. Noonan injured) that crop up in more than one reported message.  I found this a handy way to analyze or extract the data quickly.  Maybe you will too.

Joe Cerniglia
TIGHAR #3078 ECR
Title: Re: Post loss Transmissions. Solved?
Post by: Doug Giese on November 15, 2012, 09:00:09 PM
Joe,

Wow. That's an impressive spreadsheet. I didn't realize the credible intercepts were 47.5% (edit-fix) - it seemed lower just reading the raw logs.

The credible intercepts are something that's a comforting backstop. Every time I think maybe they did just crash and sink I remember the intercepts. They had to be on a shore. Maybe it's not Niku, but somewhere deserted along the LOP.

Thanks for posting the spreadsheet.
Title: Re: Post loss Transmissions. Solved?
Post by: Dan Kelly on November 15, 2012, 11:12:22 PM
Here is something I thought might be of interest for building overlay plots, or for casual interest in viewing the radio messages reported to have been heard on July 2, 1937 and the days afterward.  A year ago, I transcribed all the post-loss signal data to an Excel spreadsheet. The spreadsheet provides an easy way to group data by category of hearer, time of day, credibility assessment, frequency, and others.  You can also see many of the signals at a glance to compare and contrast.  Use the arrow at the top of the "Record Link" field to group related subjects (e.g. Noonan injured) that crop up in more than one reported message.  I found this a handy way to analyze or extract the data quickly.  Maybe you will too.

Joe Cerniglia
TIGHAR #3078 ECR

That is impressive work Joe - are you saying that around a third of the post loss signals are genuinely from Earhart. That is a lot.
Title: Re: Post loss Transmissions. Solved?
Post by: tom howard on November 16, 2012, 02:29:29 AM
Joe,

Wow. That's an impressive spreadsheet. I didn't realize the credible intercepts were 31.3% - it seemed lower just reading the raw logs.

The credible intercepts are something that's a comforting backstop. Every time I think maybe they did just crash and sink I remember the intercepts. They had to be on a shore. Maybe it's not Niku, but somewhere deserted along the LOP.

Thanks for posting the spreadsheet.

I think Joe's homemade spreadsheet lists 120 receptions logged from "earhart".
57 he rates as credible
So Joe calculates 47.5% are credible of the 120. WOW.
I don't believe even Bradenburg went there, so like beauty, "credible" is in the eye of the beholder.
Title: Re: Post loss Transmissions. Solved?
Post by: Joe Cerniglia on November 16, 2012, 04:59:08 AM
I think Joe's homemade spreadsheet lists 120 receptions logged from "earhart".
57 he rates as credible
So Joe calculates 47.5% are credible of the 120. WOW.
I don't believe even Bradenburg went there, so like beauty, "credible" is in the eye of the beholder.
Brandenburg did go there. This is the same data TIGHAR has had on its website for months. I'm not aware if the respective databases have been updated independently of each other, but I've seen no inconsistencies.  Any slight errors or omissions are mine.  However, I did take some number of weeks to build this, it has been reviewed by the same people who worked, tirelessly I might add, on cataloguing the reception data, so I have very high confidence in its rigor.  The database includes receptions known to have been sent requesting NR16020 to respond. (You can filter these in or out by selecting 'n/a' in the credibility column.) Your 47.5% does filter these out, so based on the math, that figure is TIGHAR's own interpretation, not Joe's.  If TIGHAR disagrees, it should so state.  If you disagree, sweeping generalizations won't do.  Show us your research on why specific signals can or cannot be viewed as credible. Bear in mind that the only sum total of actual signals that needs to have come from the Electra for it to have been on land somewhere in July 1937 is precisely 1.

Joe Cerniglia
TIGHAR #3078 ECR
Title: Re: Post loss Transmissions. Solved?
Post by: tom howard on November 16, 2012, 06:28:37 AM
I think Joe's homemade spreadsheet lists 120 receptions logged from "earhart".
57 he rates as credible
So Joe calculates 47.5% are credible of the 120. WOW.
I don't believe even Bradenburg went there, so like beauty, "credible" is in the eye of the beholder.
Brandenburg did go there. This is the same data TIGHAR has had on its website for months. I'm not aware if the respective databases have been updated independently of each other, but I've seen no inconsistencies.  Any slight errors or omissions are mine.  However, I did take some number of weeks to build this, it has been reviewed by the same people who worked, tirelessly I might add, on cataloguing the reception data, so I have very high confidence in its rigor.  The database includes receptions known to have been sent requesting NR16020 to respond. (You can filter these in or out by selecting 'n/a' in the credibility column.) Your 47.5% does filter these out, so based on the math, that figure is TIGHAR's own interpretation, not Joe's.  If TIGHAR disagrees, it should so state.  If you disagree, sweeping generalizations won't do.  Show us your research on why specific signals can or cannot be viewed as credible. Bear in mind that the only sum total of actual signals that needs to have come from the Electra for it to have been on land somewhere in July 1937 is precisely 1.

Joe Cerniglia
TIGHAR #3078 ECR

I will say that if you look at even Bradenburg's analysis he changes dependent on the year asked. Take for instance the "281" message supposedly sent by Amelia. First he rated not credible in his study of 4 selected important cases. Then the next study it's rated as credible. I believe he did the same for the Responses to the Hawaii radio broadcasts. First not credible. Then Credible. I have read his reports and some of it conflicts with other parts of his reports. Like the above mentioned 281 transmission.

Credible and not credible is not etched in stone, it's Brandenburg's and Tighar's interpretation.
I have heard of other forum member's concerns with Bradenburg's ratings, and the main theme of the error of Brandenburg is that practically anything received on frequency 3105KHZ, whether a hum of a generator, a carrier wave, a Microphone being keyed, he rated credible. Read the forum, some very good analysis is done right here by pilots, engineers ect.  That is what is nice about the Tighar forum. We get both sides of the coin.

 Brandenburg rated one signal as credible because a microphone was apparently keyed for 2 straight hours. I believed Gary Lapook debunked that one. I could be wrong on the poster. However, I looked at Bradenburg's charts and indeed His reasoning on most signals he rated credible- Amelia was the only licensed aircraft that could use that aircraft frequency per FCC rules, that was in the area.

That narrow view of the world at the time is problematic.
America is not the world in totality.
I have heard from others on this website and read myself that Howland and other sources picked up Japanese and Russian music on the same frequencies. That is right on this thread, and the OP did a good job of showing that problem. If Japanese music was being sent and heard on the same frequency, how can Brandenburg then pick out a carrier wave, or a microphone clicked a few times and claim that is Amelia?
Therefore FCC rules and regulations had nothing to do with the use of this channel, yet Bradenburg time and again rates signals as "credible" based on it simply being on 3105khz. I am repeating other's postings, but they make sense. These channel frequency business is not a valid reason to mark a transmission credible. I agree with that.

If you cannot see the total illogic in that, then I am sorry, I cannot explain that fallacy in the methodology any better than was already done in the previous pages. It reads like common sense to me. Other nations were using Amelia's frequency.
 There was also lot of confusion, people were hearing snippets of other boats or transmitters calling Amelia and thought it was Amelia calling back.

 I believe the Navy was correct on this one. Lot's of hoaxers, and misinterpreted signals is what the US Navy thought of these transmissions fairly quickly.

Now I hold out hope ONE signal is correct, but so far I haven't heard of it, and am losing some faith there is such a signal. I would think after a week she would have said "Here I am 350 miles south, come get me".
I have yet to to hear that transcription.

The Norwich was stranded, they called for help, and were heard right away and were rescued. Amelia has a week to call, different times to call, night and day, with the whole Pacific Navy listening. and never gets a clear message through.
Now the excuse of "broke antenna" seems weak in this case.
Lae heard her from 400 miles away. Howland is 350 miles.
So at no time during the entire week, did the atmosphere allow a full sentence saying "Here I am, come get me"
I find that odd to put it mildly.
Title: Re: Post loss Transmissions. Solved?
Post by: Greg Daspit on November 16, 2012, 04:54:37 PM
The Norwich was stranded, they called for help, and were heard right away and were rescued. Amelia has a week to call, different times to call, night and day, with the whole Pacific Navy listening. and never gets a clear message through.
Now the excuse of "broke antenna" seems weak in this case.
Lae heard her from 400 miles away. Howland is 350 miles.
So at no time during the entire week, did the atmosphere allow a full sentence saying "Here I am, come get me"
I find that odd to put it mildly.

Tom and/or other radio experts, can you answer these questions:

Regarding Lae hearing her 400 miles away and Howland not hearing her 350 miles: Does transmitting 1000 feet up in a plane work better than transmitting 0 feet up on a reef?

Regarding the comparison to the Norwich City:
Is the Norwich City’s higher and different antenna set up going to work better than the  antenna of a plane on a reef?
Was the Norwich City’s call for help in code or by voice?  Doesn't code transmit better?
Title: Re: Post loss Transmissions. Solved?
Post by: Doug Giese on November 16, 2012, 05:04:04 PM
Here's an updated composite tidal chart and radio transmission plot.

The radio transmission plot was posted by Jeff Carter here (https://tighar.org/smf/index.php/topic,944.msg20562.html#msg20562).

The tidal data is from EasyTide (http://easytide.ukho.gov.uk/EasyTide/EasyTide/index.aspx). It's for Hull Island. My understanding is Niku tides lag Hull by about 10 minutes. I didn't account for the lag in the plot because it doesn't really change the story and would complicate the plot. The chart also shows day/night.

I checked the transmit times against the radio database here (https://tighar.org/smf/index.php/topic,944.msg21617.html#msg21617) and it appears to match.

I also added the height of the Electra's wheels (52") and the propeller clearance (76") over the tidal datum as reported in the Post-Loss Signal Statistics with Tide Information (http://tighar.org/Projects/Earhart/Archives/Research/ResearchPapers/Brandenburg/TidalStudy/TidalStudy.htm) research paper. This study is six years old and there may be new hypothesis on the location of the aircraft on the reef. If it were at the edge of the reef, the wheels would be only 8" over tidal datum (and underwater much of the time), and the propeller clearance would be 32" over the tidal datum. This was added to the plot too even though not plausible.  A position on the edge would eliminate quite a few credible intercepts so the Electra had to be away from the edge.

It looks like AE/FN were in the Electra for at least the first three nights.
Title: Re: Post loss Transmissions. Solved?
Post by: tom howard on November 16, 2012, 05:28:24 PM
The Norwich was stranded, they called for help, and were heard right away and were rescued. Amelia has a week to call, different times to call, night and day, with the whole Pacific Navy listening. and never gets a clear message through.
Now the excuse of "broke antenna" seems weak in this case.
Lae heard her from 400 miles away. Howland is 350 miles.
So at no time during the entire week, did the atmosphere allow a full sentence saying "Here I am, come get me"
I find that odd to put it mildly.

Tom and/or other radio experts, can you answer these questions:

Regarding Lae hearing her 400 miles away and Howland not hearing her 350 miles: Does transmitting 1000 feet up in a plane work better than transmitting 0 feet up on a reef?

Regarding the comparison to the Norwich City:
Is the Norwich City’s higher and different antenna set up going to work better than the  antenna of a plane on a reef?
Was the Norwich City’s call for help in code or by voice?  Doesn't code transmit better?

Great question Greg, I am no radio expert, but the height of the transmission would seem like a legitimate issue. I just do not know.
Gary is good with Radios it seems from his posts, and Brandenburg, perhaps one of those two(or others could answer it).
Title: Re: Post loss Transmissions. Solved?
Post by: Joe Cerniglia on November 19, 2012, 09:47:35 PM
I'm about as far from being a radio expert as can be imagined.  The recent posts on radio message validity, however, seemed a topic worth visiting in some detail. 

I will say that if you look at even Bradenburg's analysis he changes dependent on the year asked. Take for instance the "281" message supposedly sent by Amelia. First he rated not credible in his study of 4 selected important cases. Then the next study it's rated as credible. I believe he did the same for the Responses to the Hawaii radio broadcasts. First not credible. Then Credible. I have read his reports and some of it conflicts with other parts of his reports. Like the above mentioned 281 transmission.
The word I received was that the radio signals catalog had acquired "much tougher criteria" (Gillespie, EPAC message, 7/16/10) as it passed through various stages of revision.  Many formerly credible signals were downgraded to not credible.  Would you provide links to the studies showing the thinking as it evolved?  I would be surprised if the credibility ratings to these signals were modified without an accompanying rationale for the change. 

Credible and not credible is not etched in stone, it's Brandenburg's and Tighar's interpretation.
It's Brandenburg's and TIGHAR's interpretation, but it's a quite reasoned one, based on years of comparison and rigorous analysis of the messages.

I have heard of other forum member's concerns with Bradenburg's ratings, and the main theme of the error of Brandenburg is that practically anything received on frequency 3105KHZ, whether a hum of a generator, a carrier wave, a Microphone being keyed, he rated credible. Read the forum, some very good analysis is done right here by pilots, engineers ect.  That is what is nice about the Tighar forum. We get both sides of the coin.
The objection you've stated the forum made can be checked by percentages using the radio signals spreadsheet I posted above. Filtering on Column H of the spreadsheet (the Frequency column), I get 10 signals (does not include those sent by Itasca) with a stated or assumed frequency of 3105.  Of these 10, the breakdown is 3 credible, 3 uncertain, and 4 not credible.  That is 30% credible.  The fact that these signals happened to coincide with Earhart's nighttime frequency does not appear to have entered at all into considerations of their validity.  I can see why the forum might have assumed the bias, but the database doesn't seem to bear it out.

Brandenburg rated one signal as credible because a microphone was apparently keyed for 2 straight hours. I believed Gary Lapook debunked that one. I could be wrong on the poster.

Note: I edited this section after realizing my initial counts were off.
The signal described was probably one of the weak carrier wave (CW) signals. (I can't be certain because you have not identified it with its unique identifier from the catalog, but I will estimate as well as I can.) By checking the database, I can see there are actually about 33 CW signals. Some are mixed with voice, so it's hard to categorize some definitively as CW. Some of the most relevant ones include (based on Column A, identifier column) signal numbers 40805IA, 40854IA, 40936IA, 41037IA, 41127IA, 51105HD, and 80710HD.  Fourteen of these 33 were deemed to be credible.  Twelve of the 33 were deemed to be uncertain.  Seven of the 33 were deemed not credible.  The duration of these CW signals is mostly not given, but 40850IA is said to last from 0850z to 1300z, a duration of some 4 hours.  That signal, and many other CW signals, were deemed "not credible" because it was considered implausible for Earhart to have transmitted continuously for such a long period.  The CW signals that were rated credible were given that rating usually either because a direction finder bearing on that signal was obtained or because the signal seemed to be an immediate reply to a request for a response or because the signal seemed to be occurring on Earhart's stated schedule of fifteen minutes past each hour.  No signals were rated credible because they were of a long duration. In fact, just the opposite occurred.  The duration of the signals was rather used as a basis for discounting them as not credible.

However, I looked at Bradenburg's charts and indeed His reasoning on most signals he rated credible- Amelia was the only licensed aircraft that could use that aircraft frequency per FCC rules, that was in the area.
That narrow view of the world at the time is problematic.
America is not the world in totality.
For 3105 kHz, Earhart's nighttime frequency, the sources of transmissions is stated unambiguously in the signal catalog on the TIGHAR website (http://tighar.org/Projects/Earhart/Archives/Research/ResearchPapers/Brandenburg/signalcatalog.html):

"In summary, at the time of the Earhart disappearance, by international agreement, the only legal voice radio transmissions on 3105 kHz anywhere in the world were sent by U.S. registered civil aircraft calling a limited number of airports in the continental United States, and Canadian commercial carriers flying between Vancouver and Seattle. The sole exceptions were Amelia Earhart, who had permission to use 3105 kHz as a calling frequency during her world flight, and the Coast Guard cutter Itasca whose calls were duly recorded in the ship’s radio log."

For Earhart's daytime frequency 6210 kHz, there are a few more allowed transmitters, but they are all documented:
"Other nations using 6210 kHz 5 (A3) were: Canada, for aircraft use; the Soviet Union for interior communications; and Venezuela, for broadcasting. 3105 kHz also was used by Canadian aircraft flying the route between Vancouver and Seattle."

You cite a narrow focus on U.S. broadcasting regulations, yet TIGHAR included in the list of cited sources for the information on allowed use of 3105 and 6210 kHz these international publications:
List of Frequencies, 8th Edition, International Telecommunication Union, Berne, February 1938.
List of Aeronautical Stations and Aircraft Stations, 9th Edition, International Telecommunication Union, Berne, November 1937.

Apparently, some care was taken by TIGHAR to consult world-based, in addition to U.S.-based communications regulation manuals.

I have heard from others on this website and read myself that Howland and other sources picked up Japanese and Russian music on the same frequencies. That is right on this thread, and the OP did a good job of showing that problem. If Japanese music was being sent and heard on the same frequency, how can Brandenburg then pick out a carrier wave, or a microphone clicked a few times and claim that is Amelia?
The options for which frequencies had which types of signals (CW, voice, etc.) seem more limited to me than what you describe.  Mrs. Ernest Crabb, signal #41500CB, picked up snippets of Japanese cutting in to a "conversation between a woman and a man she believed to be Amelia Earhart and Fred Noonan." Mrs. Crabb was listening on 18630 kHz (6th harmonic of 3105 kHz). Home radios at that time had poor ability to distinguish between shortwave signals at higher frequency.  This fact raises the improbable but possible instance of a Japanese hoaxer imitating Earhart and Noonan on a frequency they knew would be a harmonic of Earhart's.   But your scenario appears to link the carrier wave signals mentioned earlier on 3105 kHz with these harmonic signals on far higher frequencies. They are apples and oranges. I can't find any carrier waves in the catalog that were recorded on 3rd, 4th or 5th harmonics of Earhart's nighttime frequency.  Conversely, the only foreign broadcast (Nicaragua) that is speculated might have been received near 3105 kHz was signal #40936IA, and this signal was not voice but rather a carrier wave.  Correction: Page 166 of Finding Amelia: "Howland, too, heard a few weak signals and once picked up 'distinct Japanse music on 3105.'" 

Therefore FCC rules and regulations had nothing to do with the use of this channel,
I would think the communications law of the United States would at least have something to do with the use of 3105 kHz and 6210 kHz in 1937.

Lots of hoaxers, and misinterpreted signals is what the US Navy thought of these transmissions fairly quickly.
The U.S. Navy obviously did not hear all of the harmonics reported in the signal catalog.  The Navy could hardly have been expected to be objective about the results of its own search.  The only independent review of the search to my knowledge was a brief DOT memorandum stating the Earhart craft was presumed washed out at sea.  Edit: The memo came from the Accident Analysis Section of the Bureau of Air Commerce, May 5, 1938. (Finding Amelia, 2006, p. 238)

Now I hold out hope ONE signal is correct, but so far I haven't heard of it, and am losing some faith there is such a signal. I would think after a week she would have said "Here I am 350 miles south, come get me".
I have yet to to hear that transcription.
Here is a chart listing the signals in which a lat-long position was said to be given:

Signal #    Agency/Person              Lat-Long                                                                                 
30800LE   Mrs. Mabel Larremore   stated but not saved by hearer                         Credible
70030LC   Thelma Lovelace          stated but not saved by hearer                         Credible
80540HS   Ray Havens                 "173 west longitude and 5 south latitude"         Not credible

(Nikumaroro's actual position is 174.517 west longitude and 4.68 south latitude, but it had been reported in the media that the Phoenix Islands were to be searched.  Mr. Havens could have picked out Nikumaroro's coordinates from a map.)

The Norwich was stranded, they called for help, and were heard right away and were rescued. Amelia has a week to call, different times to call, night and day, with the whole Pacific Navy listening. and never gets a clear message through.
Now the excuse of "broke antenna" seems weak in this case.
Lae heard her from 400 miles away. Howland is 350 miles.
So at no time during the entire week, did the atmosphere allow a full sentence saying "Here I am, come get me"
I find that odd to put it mildly.
Having no knowledge of the capabilities of the N.C. transmitter, I cannot venture to comment.  I believe it was the receiving antenna, not the transmitting antenna, that was believed to have become lost from the Electra during its takeoff run.  I think the question of the comparative capabilities of the respective radios on the N.C. and the Electra is a good one and may deserve a new thread.

Thanks Tom for an interesting evening looking at the radio signal possibilities.

Joe Cerniglia
TIGHAR #3078 ECR
Title: Re: Post loss Transmissions. Solved?
Post by: tom howard on November 20, 2012, 02:32:36 PM
Joe here is a 2000 report by Bradenburg stating that the radio intercepts by the Achilles and the "281" message both could not have come from Gardner.

http://tighar.org/Projects/Earhart/Archives/Research/ResearchPapers/Brandenburg/postlossradio.html

Yes, I agree,  interpretation methods might have improved since 2000. That seems to be the case with reports later revised. But you asked for an example where the determination of not credible to credible occurred so the link is attached. Make your own determination if the changing of credibility status is warranted.

Title: Re: Post loss Transmissions. Solved?
Post by: Chuck Varney on November 20, 2012, 02:48:19 PM

I have heard of other forum member's concerns with Bradenburg's ratings, and the main theme of the error of Brandenburg is that practically anything received on frequency 3105KHZ, whether a hum of a generator, a carrier wave, a Microphone being keyed, he rated credible.
The objection you've stated the forum made can be checked by percentages using the radio signals spreadsheet I posted above. Filtering on Column H of the spreadsheet (the Frequency column), I get 10 signals (does not includes those sent by Itasca) with a stated or assumed frequency of 3105.  Of these 10, the breakdown is 3 credible, 3 uncertain, and 4 not credible.  That is 30% credible. 

Those are interesting numbers, Joe. I just went through the post-loss signal catalog (http://tighar.org/Projects/Earhart/Archives/Research/ResearchPapers/Brandenburg/signalcatalog.html), counting non-Itasca messages on 3105 kHz. I eliminated all messages where 3105 kHz was indicated to be either approximate or assumed. The result was 60 total messages, of which 38 (63%) were assessed credible, 15 (25%) uncertain, and 7 (12%) not credible.

Chuck
Title: Re: Post loss Transmissions. Solved?
Post by: Joe Cerniglia on November 20, 2012, 03:16:18 PM
Chuck,
I'd be happy to take a look ar what you found if you would like to attach your copy of the spreadsheet.  If you could have the rows you left out of your totals either be filtered or hidden that would make it easier to compare.  I'm having difficulty duplicating your filter. 

What was your reason for filtering out 3105 kHz?  Do you draw any conclusions from the ratios you observed?

Thanks.

Joe Cerniglia
TIGHAR #3078 ECR
Title: Re: Post loss Transmissions. Solved?
Post by: Chuck Varney on November 20, 2012, 04:05:55 PM
Credible and not credible is not etched in stone, it's Brandenburg's and Tighar's interpretation.
It's Brandenburg's and TIGHAR's interpretation, but it's a quite reasoned one, based on years of comparison and rigorous analysis of the messages.

They’re dealing with avowed radio transmissions from an aircraft parked on an atoll in the middle of the Pacific. If an analyst is uninterested in what a reasonable estimate of the signal levels of those transmissions might have been, then he might compare and analize forever--laboring under a misapprehension that will color his assessments, don’t you think? This work,  (http://tighar.org/Projects/Earhart/Archives/Research/ResearchPapers/Brandenburg/WE-13.htm)by one of the analysts, is not a reasonable estimate. (I indicated why  (http://tighar.org/smf/index.php/topic,418.msg6350.html#msg6350)more than a year ago.)

Chuck
Title: Re: Post loss Transmissions. Solved?
Post by: Joe Cerniglia on November 20, 2012, 05:55:14 PM
They’re dealing with avowed radio transmissions from an aircraft parked on an atoll in the middle of the Pacific. If an analyst is uninterested in what a reasonable estimate of the signal levels of those transmissions might have been, then he might compare and analize forever--laboring under a misapprehension that will color his assessments, don’t you think?
Yes. If the signal levels were underestimated, that would be a flaw.  I'm not an electrical engineer, so I'm in no position to verify the specifics of anyone's work in this area. Are there any unknown variables over which we have limited knowledge that could alter the equation in either direction?  In other words, what is our range of uncertainty?

Joe Cerniglia
TIGHAR #3078 ECR

Title: Re: Post loss Transmissions. Solved?
Post by: Dan Kelly on November 20, 2012, 06:31:14 PM
They’re dealing with avowed radio transmissions from an aircraft parked on an atoll in the middle of the Pacific. If an analyst is uninterested in what a reasonable estimate of the signal levels of those transmissions might have been, then he might compare and analize forever--laboring under a misapprehension that will color his assessments, don’t you think?
Yes. If the signal levels were underestimated, that would be a flaw.  I'm not an electrical engineer, so I'm in no position to verify the specifics of anyone's work in this area. Are there any unknown variables over which we have limited knowledge that could alter the equation in either direction?  In other words, what is our range of uncertainty?

Joe Cerniglia
TIGHAR #3078 ECR

I'm not a radio expert Mr Cerniglia, and not much of an expert anything. But I don't follow what you mean when you talk about "unknown variables about which we limited knowledge". If we say they are unknown then I don't know how we could have limited knowledge of them. Wouldn't that mean we know something. Sorry if that is a bit muddled but that's how I see it.  :)
Title: Re: Post loss Transmissions. Solved?
Post by: Joe Cerniglia on November 20, 2012, 07:02:42 PM
Dan,
The holidays have me busily multi-tasking at the moment, and consequently my writing may be poorly phrased. 

I'm saying that in any computed probability there must be certain variables whose value is more accurately a range, not a discrete value.  Certainly there must be some factors affecting radio propagation that would change from moment to moment in a rather unpredictable way.  I don't know what those variables are, but I would guess the experts know.  Sunspots, maybe?  Lightning strikes?  I'm guessing.  These things would need to be computed in a function assessing signal strength as part of a range of values, rather than as a single value.  As a result of this range of input variables, the output (signal strength) itself would also be expressed as a range. This is what I mean by "unknown variables over which we have limited knowledge," i.e., some knowledge (such as, yes, there were lightning strikes on that day) but not perfect knowledge (I can't say exactly how much they contributed to the SNR at that particular moment of transmission.)

Usually when an expert confronts another expert, he will say things like, "Your estimate is overly optimistic" (implying this continuum of values).

Another way of asking this question would be, "Does the range of probability for each reception Chuck Varney would calculate overlap, even in a small way, the range of probability for each reception Brandenburg would calculate?" 

Most important is the bottom line.  How would a difference of calculated strength of transmission change the probability that certain people heard what they said they heard?

This is a very hasty post.  My lack of expertise doesn't allow me to ask these things in a more precise way.  Am I making any sense?

Joe Cerniglia
TIGHAR #3078 ECR
Title: Re: Post loss Transmissions. Solved?
Post by: Joe Cerniglia on November 20, 2012, 07:11:46 PM
Joe here is a 2000 report by Bradenburg stating that the radio intercepts by the Achilles and the "281" message both could not have come from Gardner.

http://tighar.org/Projects/Earhart/Archives/Research/ResearchPapers/Brandenburg/postlossradio.html

Yes, I agree,  interpretation methods might have improved since 2000. That seems to be the case with reports later revised. But you asked for an example where the determination of not credible to credible occurred so the link is attached. Make your own determination if the changing of credibility status is warranted.
I've reviewed some of the differences, and I think the changing credibility status appears to be warranted.  I did not have time to review every possible detail, but one thing I did notice is that the knowledge of the contextual details has improved with time.  Citing one example, Brandenburg was doubtful in 2000 why the HMS Achilles should have heard dashes in response to a request from Itasca to send dashes and yet the Itasca had not heard this response.  Randy Jacobson later unearthed a message from the Coast Guard San Francisco Division to the Itasca on June 25, 1937, in which the Itasca was advised, "Reports indicate Itasca receivers not functioning properly or antenna system poor. Suggest doublet antenna system for high frequencies be discarded as results obtained this station indicate twisted pair fenders now on Itasca doublet useless.  Suggest using high frequency transmitting antenna for receiving..."  (I added the periods for readability.)  Brandenburg based his estimate of signal reception solely on signal-to-noise ratio (SNR), not on the condition of Itasca's equipment. 

I'm sure I could find more details if I had the time to check why Brandenburg changed his credibility rating for the other signals.  Perhaps I can resume looking at it at a later time.

It was perceptive on your part to note that this change from "not credible" to "credible" had occurred in a few of the signals.

Joe Cerniglia
TIGHAR #3078 ECR
Title: Re: Post loss Transmissions. Solved?
Post by: Dan Kelly on November 20, 2012, 08:40:23 PM

This is a very hasty post.  My lack of expertise doesn't allow me to ask these things in a more precise way.  Am I making any sense?

Joe Cerniglia
TIGHAR #3078 ECR

Thank you Mr Cerniglia for taking the time to answer my question. I sort of understand now.
Title: Re: Post loss Transmissions. Solved?
Post by: Chuck Varney on November 21, 2012, 09:39:24 AM
Chuck, I'd be happy to take a look ar what you found if you would like to attach your copy of the spreadsheet.  If you could have the rows you left out of your totals either be filtered or hidden that would make it easier to compare.  I'm having difficulty duplicating your filter.

Joe, I didn’t use a spreadsheet. Your numbers, which appeared unbelievably small, motivated me to look at the post-loss signal catalog. Once there, I scrolled through each page noting the non-Itasca signals that were listed, without qualification, as having a frequency of 3105 kHz. That method constituted my "filter".

If I’d included the 3105 kHz non-Itasca signals with the frequency tagged either “assumed” or “approximately”, the result would have been something like: 67 total,  41 (61%) credible, 16 (24%) uncertain, and 10 (15%) not credible.
 
Quote
What was your reason for filtering out 3105 kHz?

I don’t understand the question.

Quote
Do you draw any conclusions from the ratios you observed?

Yes. The numbers you posted don’t reflect the content of the post-loss signal catalog.

Chuck
Title: Re: Post loss Transmissions. Solved?
Post by: Alan Harris on November 21, 2012, 07:01:03 PM
I scrolled through each page noting the non-Itasca signals that were listed, without qualification, as having a frequency of 3105 kHz.

I come from the wrong engineering discipline to have much intelligent to say in this area, but previous posters have mentioned that, unlike amateur "ham" gear, the Electra's Model 13C transmitter was professional equipment with frequency controlled by crystal.  It would always be precisely on one characteristic frequency and any signal logged as being of "varying frequency", or "nearly on 3105", "on or about 3105" etc. would be prima facie not credible.  This may be, in part, what Mr. Varney is referring to here.
Title: Re: Post loss Transmissions. Solved?
Post by: Joe Cerniglia on November 21, 2012, 07:16:02 PM

Quote
Do you draw any conclusions from the ratios you observed?

Yes. The numbers you posted don’t reflect the content of the post-loss signal catalog.

Chuck
Chuck,
Your conclusion is valid.  I goofed on the numbers for 3105 transmissions.  The reason for the error is that I used "contains 3105" as my filter and for some reason this did not include those that simply equalled 3105.  Had I been more careful in checking this without the filter with a manual count, I would have caught this.  I apologize for the error.  My point in running these numbers was to try to attempt to see whether some bias had existed for credibility rating based on frequency. On further (but not very much) reflection, it seems bias here is pretty tough to prove or disprove.  In either case, I'll re-run my numbers after the holidays and re-post.  Perhaps it may be a moot point in that one could argue there should be a bias to signals received on Earhart's nighttime and daytime frequencies.  But this thought is hastily conceived and I will ponder it more when I have more time.

Joe Cerniglia
TIGHAR #3078 ECR
Title: Re: Post loss Transmissions. Solved?
Post by: Martin X. Moleski, SJ on November 21, 2012, 10:57:28 PM
I come from the wrong engineering discipline to have much intelligent to say in this area, but previous posters have mentioned that, unlike amateur "ham" gear, the Electra's Model 13C transmitter was professional equipment with frequency controlled by crystal.  It would always be precisely on one characteristic frequency and any signal logged as being of "varying frequency", or "nearly on 3105", "on or about 3105" etc. would be prima facie not credible.

You are, of course, assuming--something frowned upon among the engineers of my acquaintance--that all of the receivers involved were properly calibrated and that there would be no difficulty reading the dial to the least significant digit.
Title: Re: Post loss Transmissions. Solved?
Post by: Alan Harris on November 22, 2012, 12:40:09 AM
You are, of course, assuming . . . that all of the receivers involved were properly calibrated and that there would be no difficulty reading the dial to the least significant digit.

Actually I wasn't assuming those things at all, I was casually over-simplifying to a degree with which you are not comfortable.  Reading it again, I'm not that comfortable either.  :)  To be more accurate and still be brief, it should have said ". . . would be prima facie suspect as to credibility."  Or to be more long-winded, it could have said that a received signal further off 3105 than known calibration limits of the receiver would lose credibility; that a signal observed to vary in frequency while monitored would have little/no credibility; and that if the same station received 2 separate signals within a fairly short time that were significantly different in frequency, at least one of those signals would be of very doubtful credibility.  Reading back over that, I think I prefer the brief version.    :)

Quote
. . . assuming--something frowned upon among the engineers of my acquaintance . . .

Matter of opinion, I guess, but in mine and my instructors', engineers make assumptions all the time.  That is what distinguishes engineering from pure science and enables things to actually be designed and built within a practically useful time frame.  Apart from basic science and math, engineering education consists largely of training in such things as what previous assumptions have been found to be sound and useful over time, estimating risks or inaccuracies involved in assumptions made, etc.  Engineers read the books assiduously but they don't re-research and rewrite the books before starting each new project.
Title: Re: Post loss Transmissions. Solved?
Post by: Dan Kelly on November 22, 2012, 02:30:22 AM

You are, of course, assuming--something frowned upon among the engineers of my acquaintance ......

Father Moleski that made me laugh out loud.

About 15 years ago I was working on an engineering project where we were using big overhead blower ducts to carry finely crushed ore from where it was trucked in, to the smelters. The big pylons and the ducts (roughly 2 yards in diameter) were being designed by an engineering company that were partners with the company I was contracting for. Anyway their designers assumed that the site was on an even slope, and none of our engineers checked their calculations. Anyway these huge pylons and the mountings were being fabricated off site by another engineering company who just fabricated what they were told to build.

Anyway things were going real well until the site construction manager discovered that the ducts were all of sudden going upwards at a steady angle while the pylons were not reaching the same height. Turned out that the engineer responsible for the overall design hadn't noticed that the ground level actually flattened out. I bet that if we had continued these huge ducts would have been in Earth orbit by now. ;D 

I reckon everyone assumes sometime or other even philosophers  :)     
Title: Re: Post loss Transmissions. Solved?
Post by: Martin X. Moleski, SJ on November 22, 2012, 06:17:45 AM
Actually I wasn't assuming those things at all, I was casually over-simplifying to a degree with which you are not comfortable.  Reading it again, I'm not that comfortable either.  :)  To be more accurate and still be brief, it should have said ". . . would be prima facie suspect as to credibility."  Or to be more long-winded, it could have said that a received signal further off 3105 than known calibration limits of the receiver would lose credibility; that a signal observed to vary in frequency while monitored would have little/no credibility ...

I haven't worked a lot with old-time tube radios.  If this was a common phenomenon, either because of defects in the transmitter or receiver, and if the person operating the radio was truthful in reporting their observation of their instrument, it simply "is what it is."

Quote
Quote
. . . assuming--something frowned upon among the engineers of my acquaintance . . .

Matter of opinion, I guess, but in mine and my instructors', engineers make assumptions all the time. ...

If the assumptions are sound, the bridge probably won't collapse; if the assumptions are groundless, people may die.  Canadian engineers wear iron rings (http://en.wikipedia.org/wiki/Iron_Ring) on their pinky fingers to remind themselves of what can happen if they make the wrong kind of assumptions.
Title: Re: Post loss Transmissions. Solved?
Post by: Bob Lanz on November 22, 2012, 08:51:02 AM
Actually I wasn't assuming those things at all, I was casually over-simplifying to a degree with which you are not comfortable.  Reading it again, I'm not that comfortable either.  :)  To be more accurate and still be brief, it should have said ". . . would be prima facie suspect as to credibility."  Or to be more long-winded, it could have said that a received signal further off 3105 than known calibration limits of the receiver would lose credibility; that a signal observed to vary in frequency while monitored would have little/no credibility ...

I haven't worked a lot with old-time tube radios.  If this was a common phenomenon, either because of defects in the transmitter or receiver, and if the person operating the radio was truthful in reporting their observation of their instrument, it simply "is what it is."

Quote
Quote
. . . assuming--something frowned upon among the engineers of my acquaintance . . .

Matter of opinion, I guess, but in mine and my instructors', engineers make assumptions all the time. ...

If the assumptions are sound, the bridge probably won't collapse; if the assumptions are groundless, people may die.  Canadian engineers wear iron rings (http://en.wikipedia.org/wiki/Iron_Ring) on their pinky fingers to remind themselves of what can happen if they make the wrong kind of assumptions.

Interesting story about the Canadian Engineers iron rings Marty.  That said, the cost of my Professional Liability Insurance always reminded me of what could happen if I made the wrong kind of assumptions.   ;D
Title: Re: Post loss Transmissions. Solved?
Post by: Ranchodoug on November 23, 2012, 01:32:22 PM

The tidal data is from EasyTide (http://easytide.ukho.gov.uk/EasyTide/EasyTide/index.aspx). It's for Hull Island. My understanding is Niku tides lag Hull by about 10 minutes.

I checked the transmit times against the radio database here (https://tighar.org/smf/index.php/topic,944.msg21617.html#msg21617) and it appears to match.

I also added the height of the Electra's wheels (52") ...It looks like AE/FN were in the Electra for at least the first three nights.
Is is possible for you to post the raw data from the "Easy Tide" site that you used for Hull Island?

Here you go. They are unfortunately not machine readable.

At any rate, based on the original 52" height in the Brandenberg study the wheels barely got wet at the highest tide, and the high/low tides had nothing to do with the transmit times (this was mentioned). I wonder if propagation wasn't just better at night.

With the revised location (22") there are times where there wasn't enough propeller clearance for a credible transmission (0200-0800 July 3-4 Niku time). The Electra need to be at least 30" above the tidal datum (this is a small amount). A revised tidal chart is posted.

Thanks Jeff Carter for the very insightful way of looking at the transmissions.

Posted w/o attribution.

Title: Re: Post loss Transmissions. Solved?
Post by: John Ousterhout on November 26, 2012, 10:41:07 AM
'Just a reminder that one assumption to remain aware of is that the necessary propeller tip clearances assumes fully inflated tires on a flat surface.  A flat aircraft tire obviously brings a prop tip considerably closer to surface.  Likewise, a wheel sitting in a depression also brings the prop tip closer to the surface.  In the reef landing and transmitting hypothesis, there may be some correlation between transmit times and decreasing tip clearance. 
Title: Re: Post loss Transmissions. Solved?
Post by: Alan Harris on November 26, 2012, 07:50:22 PM
The more I look at Purdue photos, the more I am inclined to think (or: opine, speculate: choose any or all of those) that the prop clearance on level ground was significantly more than the 24 inches I've seen assumed.

Photos such this one from Assab, Africa (http://earchives.lib.purdue.edu/cdm4/item_viewer.php?CISOROOT=/earhart&CISOPTR=434&CISOBOX=1&REC=2).  Unless the man is remarkably short, it certainly appears that the prop tip would be closer to the top of a typical leg rather than at typical 24" knee height.

Other photos suggestive to me include ones from Indonesia (http://earchives.lib.purdue.edu/cdm4/item_viewer.php?CISOROOT=/earhart&CISOPTR=296&CISOBOX=1&REC=15); Dakar, Africa (http://earchives.lib.purdue.edu/cdm4/item_viewer.php?CISOROOT=/earhart&CISOPTR=294&CISOBOX=1&REC=6); and Massawa, Africa (http://earchives.lib.purdue.edu/cdm4/item_viewer.php?CISOROOT=/earhart&CISOPTR=654&CISOBOX=1&REC=12).

Comparing both to persons in the photos and to the height of the Electra's MLG tires (which are believed to be 35" or 36" unloaded diameter), my personal estimate for prop clearance is more in the range of 32" to 36".

Note that I am not stating this as a fact.  Also please note that I am aware of the effects of perspective in photos, and that dimensions of objects not in the same spatial plane, etc. can be deceiving, and don't need reminding of that.  I'm just relating my interpretation of what I see.

I started looking at the photos for this because I was messing around with some scaled sketches of the Electra for my own amusement, and it seemed, using the assumed 9-foot props and ~35" tires, that I was having to "squat" the gear down more than seemed right to get the prop tips down to 24" from ground.  I do not offer this as "evidence" because, as I said, it is just me messing around.
Title: Re: Post loss Transmissions. Solved?
Post by: Joe Cerniglia on November 26, 2012, 08:08:36 PM
Joe, I didn’t use a spreadsheet. Your numbers, which appeared unbelievably small, motivated me to look at the post-loss signal catalog. Once there, I scrolled through each page noting the non-Itasca signals that were listed, without qualification, as having a frequency of 3105 kHz. That method constituted my "filter".

If I’d included the 3105 kHz non-Itasca signals with the frequency tagged either “assumed” or “approximately”, the result would have been something like: 67 total,  41 (61%) credible, 16 (24%) uncertain, and 10 (15%) not credible.
 

Quote
Do you draw any conclusions from the ratios you observed?

Yes. The numbers you posted don’t reflect the content of the post-loss signal catalog.

Chuck
Chuck,
I've had a chance to sit down and correct my earlier tally of the 3105 kHz signal receptions on the Signal Catalog spreadsheet. I did a manual count (includes approximates) and came up with the following:
85 total,  44 (52%) credible, 22 (26%) uncertain, and 19 (22%) not credible. 

A spreadsheet with minor modifications to reflect the calculations is attached.  Note that this iteration of the spreadsheet is not meant to supersede the earlier one, only to reflect my specific purpose in this particular exercise with the 3105 kHz signals.

I double-checked my counts using the DCOUNTA function in Excel at cell E195 in the worksheet titled "Signal Catalog."  I also created a column to indicate whether or not I included a given signal as part of my 3105 kHz total.  This column may be found at Column R and is labeled "3105 reception (not transmission)."  The value for each cell in this column is simply "yes" or "no."  By using the arrow in cell R1, you can filter on the "yes" values to view which rows I selected.  You can filter on the "no" values to view which rows I did not select.  Note that Itasca transmissions were counted as "no."

While my math was wrong earlier (due to a faulty assumption on my part regarding Microsoft Excel filters), the database itself is, to my knowledge, correct and in exact correspondence to the signal catalog that is on the TIGHAR website.  If it is not, please tell me about it, and where it diverges, so that I can make the necessary adjustment.

The reason I originally undertook the exercise was to investigate a poster's claim that a signal received on 3105 kHz stood an inordinately high chance of receiving a rating of credible.  That nearly half (48%) of the signals received on or near 3105 kHz were assigned a rating other than "credible" seems to indicate to me that numerous other criteria, in addition to the frequency of the signal, were applied to the signal credibility ratings.  A quick perusal of the "Qualifying Factors" column (Column L) should confirm this observation.  Again, if anyone feels differently, please let me know so that I can reassess if I am missing something.

Joe Cerniglia
TIGHAR #3078 ECR
Title: Re: Post loss Transmissions. Solved?
Post by: John Kada on November 26, 2012, 10:43:15 PM
The more I look at Purdue photos, the more I am inclined to think (or: opine, speculate: choose any or all of those) that the prop clearance on level ground was significantly more than the 24 inches I've seen assumed.

Photos such this one from Assab, Africa (http://earchives.lib.purdue.edu/cdm4/item_viewer.php?CISOROOT=/earhart&CISOPTR=434&CISOBOX=1&REC=2).  Unless the man is remarkably short, it certainly appears that the prop tip would be closer to the top of the leg rather a typical 24" knee height.

Other photos suggestive to me include ones from Indonesia (http://earchives.lib.purdue.edu/cdm4/item_viewer.php?CISOROOT=/earhart&CISOPTR=296&CISOBOX=1&REC=15), Dakar, Africa (http://earchives.lib.purdue.edu/cdm4/item_viewer.php?CISOROOT=/earhart&CISOPTR=294&CISOBOX=1&REC=6), and Massawa, Africa (http://earchives.lib.purdue.edu/cdm4/item_viewer.php?CISOROOT=/earhart&CISOPTR=654&CISOBOX=1&REC=12).

Comparing both to persons in the photos and to the height of the Electra's MLG tires (which are believed to be 35" or 36" unloaded diameter), my personal estimate for prop clearance is more in the range of 32" to 36".

Note that I am not stating this as a fact.  Also please note that I am aware of the effects of perspective in photos, and that dimensions of objects not in the same spatial plane, etc. can be deceiving, and don't need reminding of that.  I'm just relating my interpretation of what I see.

I started looking at the photos for this because I was messing around with some scaled sketches of the Electra for my own amusement, and it seemed, using the assumed 9-foot props and ~35" tires, that I was having to "squat" the gear down more than seemed right to get the prop tips down to 24" from ground.  I do not offer this as "evidence" because, as I said, it is just me messing around.

Another photo that may be of interest was taken in Burma (http://earchives.lib.purdue.edu/cdm4/item_viewer.php?CISOROOT=/earhart&CISOPTR=769&CISOBOX=1&REC=5)

Title: Re: Post loss Transmissions. Solved?
Post by: Alan Harris on November 26, 2012, 11:12:36 PM
Another photo that may be of interest was taken in Burma (http://earchives.lib.purdue.edu/cdm4/item_viewer.php?CISOROOT=/earhart&CISOPTR=769&CISOBOX=1&REC=5)

Thanks, John, you are indeed correct.  I don't know how I missed that one.  If anything, my own estimate for prop clearance height just went further upward with that one.
Title: Re: Post loss Transmissions. Solved?
Post by: Dan Kelly on November 26, 2012, 11:54:04 PM
I wonder what the variance in height was when the aircraft was loaded and unloaded - if any. On the reef it would have been quite light so maybe less compression on the gear?
Title: Re: Post loss Transmissions. Solved?
Post by: Gary LaPook on November 27, 2012, 03:48:47 AM

The tidal data is from EasyTide (http://easytide.ukho.gov.uk/EasyTide/EasyTide/index.aspx). It's for Hull Island. My understanding is Niku tides lag Hull by about 10 minutes.

I checked the transmit times against the radio database here (https://tighar.org/smf/index.php/topic,944.msg21617.html#msg21617) and it appears to match.

I also added the height of the Electra's wheels (52") ...It looks like AE/FN were in the Electra for at least the first three nights.
Is is possible for you to post the raw data from the "Easy Tide" site that you used for Hull Island?

Here you go. They are unfortunately not machine readable.

At any rate, based on the original 52" height in the Brandenberg study the wheels barely got wet at the highest tide, and the high/low tides had nothing to do with the transmit times (this was mentioned). I wonder if propagation wasn't just better at night.

With the revised location (22") there are times where there wasn't enough propeller clearance for a credible transmission (0200-0800 July 3-4 Niku time). The Electra need to be at least 30" above the tidal datum (this is a small amount). A revised tidal chart is posted.

Thanks Jeff Carter for the very insightful way of looking at the transmissions.

Posted w/o attribution.
I was wondering where you got the height of 22 inches for the revised location on the surface of the reef but I see you calculated it by comparing the graph that Ric produced (https://tighar.org/smf/index.php?action=dlattach;topic=916.0;attach=4688) with the UK tide data.
Comparing the height of the same high tide, July 9, 1937 at 7:06 am, from the UK tide data site showing 4.6 feet, 53 inches, with the height of the same tide on the graphic from TIGHAR of 0.82 meters, 33 inches, it is clear that the difference, 22 inches, is the height of the reef surface as determined by TIGHAR. I have attached annotated copies of each that shows this.

gl

https://tighar.org/smf/index.php?action=dlattach;topic=916.0;attach=4688 (https://tighar.org/smf/index.php?action=dlattach;topic=916.0;attach=4688)

https://tighar.org/smf/index.php/topic,916.msg21293.html#msg21293 (https://tighar.org/smf/index.php/topic,916.msg21293.html#msg21293)
Title: Re: Post loss Transmissions. Solved?
Post by: Ric Gillespie on November 27, 2012, 08:02:21 AM
Apologies for the tardiness of this reply but I'm just now catching up with recent contributions to this thread.

I agree that the photos cited suggest more prop clearance than the 24 inches we have been using.  That distance is based upon the Harney Drawings and it may be that there is a scaling error there.  The best way to check would be to measure the clearance on an existing 10E that has the same props and tires as NR16020.  There are two surviving Electras in 10E configuration:
• c/n 1015 used by Linda Finch in her 1997 world flight and later bought by the late Mike Kammerer.  The Seattle Museum of Flight is currently trying to raise the money to buy the airplane from Kammerer's heirs. Last I heard it was stored in a hangar in Santa Fe, NM.
• c/n 1042 is owned by Grace McGuire. At last report it was stored at Gillespie Field near San Diego.

I don't think either aircraft is fitted with the big fat Goodyear Airwheels that were on NR16020.

If the length of the prop blades and the height of the prop shaft off the ground are the same for the R-985 equipped 10A as on the R-1340 equipped 10E, we could measure the clearance on c/n 1052 at the New England Air Museum.  It has Goodyear Airwheels.  I'm not an aeronautical engineer, but it seems to me that the prop shaft would have to be in the same place regardless of engine size.

If it is true that the clearance is greater than we have used in our calculations of when the engine could be run to charge the batteries, the Post-Loss Radio hypothesis may be stronger than we thought.  At present, we have a few occasions when credible messages were received at times when the engine could not be run due to the water level on the reef, but it may be that we can legitimately move that red "propeller clearance" line up a bit. For example, if 32" is the right number for prop clearance, the red line on the attached graph moves up to .8 meter and all of the credible messages sent on the night of July 3-4 can be sent with the engine running.

All the talk about tide heights completely misunderstands the calculation of water levels on the reef at Niku.  I don't have time to explain it again.
Title: Re: Post loss Transmissions. Solved?
Post by: Dan Swift on November 27, 2012, 08:42:29 AM
In the Assab, Africa picture, the prop is almost at its lowest point.....and where is falls on the gentlemen directly in front of it......on me is about 29-30".  I am exactly 6' tall. 
Title: Re: Post loss Transmissions. Solved?
Post by: Ric Gillespie on November 27, 2012, 09:11:28 AM
In the Assab, Africa picture, the prop is almost at its lowest point.....and where is falls on the gentlemen directly in front of it......on me is about 29-30".  I am exactly 6' tall.

His head is even with the lower lip of the cowling.  If we can find a photo of either AE (5' 7or 8") or FN (6 ft) standing in the same relative location, regardless of the prop orientation, we should be able to estimate Mr. Assab's height.
Title: Re: Post loss Transmissions. Solved?
Post by: Tom Swearengen on November 27, 2012, 11:31:20 AM
Like these?
Title: Re: Post loss Transmissions. Solved?
Post by: Ric Gillespie on November 27, 2012, 12:42:31 PM
Like these?

No.  As I said, either AE or FN has to be standing where the guy is standing in the Assab photo.
Title: Re: Post loss Transmissions. Solved?
Post by: Dan Swift on November 27, 2012, 02:36:53 PM
Oh and that 29" or so is considering both a fully inflated right tire and it is not sitting down in a rutt. 
Title: Re: Post loss Transmissions. Solved?
Post by: John Ousterhout on November 27, 2012, 03:03:01 PM
In  this Purdue collection photo (http://tighar.org/Projects/Earhart/Archives/Research/Bulletins/58_NessieHypothesis/05proptoprop.jpg), AE is standing in the same plane as the prop hubs, making it easy to make a fairly accurate measurement of their height compared to hers, without significant parallax.  I printed the picture to measure with a caliper, and also used MS Paint to count pixels directly, getting a range of indicated ratios of hub height/AE height(s) from 1.221 to 1.226.  Combined with her range of heights as 67 to 68 inches, these translate into indicated hub heights of 81.8 to 83.4 inches.

I assume she and the hubs are in essentially the same plane, since she is touching the prop tips with her fingers, arms stretched to their near maximum reach.  The props are nearly horizontal, so the tips are not yet far out of plane.  She cannot be standing significantly in front, nor behind the prop tips, and appears to be standing quite upright to her full height, with the possible exception of her head tilting to her left, maybe to clear the fuselage.  It is also not clear what she is wearing on her feet.

At the scale I printed the picture, I measured her height as 53.45 mm, and the prop hubs as 65.35mm.  I would be pleased to describe details of how to construct the bottom reference line, but suffice to say it runs under her feet, parallel to the hubs and horizon which is visible in the background.  There is enough information in the photo to work out the scale using the prop lengths, which I leave for some other time.  Simple pencil scaling indicates something close to 27 inches clearance from tip to ground, but there is some out of plane parallax foreshortening still needing to be accounted for, in that case.

YMMV
Title: Re: Post loss Transmissions. Solved?
Post by: Greg Daspit on November 27, 2012, 04:51:59 PM
I scaled the photo in AutoCAD so AE is 5'-8"
Due to her hair and shoes, her height can't be determined precisely nor do I know if she is actually 5'-8"
The prop on the right appears to be farther back, the plane is rotated slightly and the photo not taken head on so this just ballpark stuff. Two different dimensions for the props are likely due to the plane being rotated and this is taken from a photo and not a elevation drawing. I think she is more aligned with the prop on the left and I get about 2'-2". What I got is attached in the pdf
Again just quick ballpark stuff
edit, Also I used circles and should have used elipses due to the angle of the prop not bing head on
Title: Re: Post loss Transmissions. Solved?
Post by: Chuck Varney on November 27, 2012, 05:51:59 PM
I've had a chance to sit down and correct my earlier tally of the 3105 kHz signal receptions on the Signal Catalog spreadsheet. I did a manual count (includes approximates) and came up with the following: 85 total,  44 (52%) credible, 22 (26%) uncertain, and 19 (22%) not credible.

Joe, your total of 85 includes 19 messages that have “Itasca” as the Agency/Person. These lie between message 10 and message 73, inclusive. Your total also includes message 75, which relates to 3105 kHz only in that it reports nothing has been heard on that frequency for two hours. Remove those 20 messages and your reduced total of 65 should then have a breakdown something like this: 40 (~61%) credible, 9 (~14%) not credible, and 16 (~25%) uncertain.

Quote
The reason I originally undertook the exercise was to investigate a poster's claim that a signal received on 3105 kHz stood an inordinately high chance of receiving a rating of credible.

Something like a 40 to 9 ratio of credible to not credible assessments may have motivated that poster’s claim.

Chuck
Title: Re: Post loss Transmissions. Solved?
Post by: Alan Harris on November 27, 2012, 06:10:01 PM
Combined with her range of heights as 67 to 68 inches, these translate into indicated hub heights of 81.8 to 83.4 inches.

Just using these hub heights and correcting for the prop axes being rotated upward in pitch, the clearance comes out right around 30".  That certainly seems more reasonable to me than the 24", maybe still a bit low by the "eyeball" or "gut feel" tests, lol.  This is all approximate, to name one thing the photo doesn't show whether the plane is pitched up or down from "normal" due to ground height differences between the main wheels and tail wheel.  Also hard to say whether the main tires being on a sandy instead of a hard surface affects things significantly or not.
Title: Re: Post loss Transmissions. Solved?
Post by: Joe Cerniglia on November 27, 2012, 07:06:16 PM
I've had a chance to sit down and correct my earlier tally of the 3105 kHz signal receptions on the Signal Catalog spreadsheet. I did a manual count (includes approximates) and came up with the following: 85 total,  44 (52%) credible, 22 (26%) uncertain, and 19 (22%) not credible.

Joe, your total of 85 includes 19 messages that have “Itasca” as the Agency/Person. These lie between message 10 and message 73, inclusive. Your total also includes message 75, which relates to 3105 kHz only in that it reports nothing has been heard on that frequency for two hours. Remove those 20 messages and your reduced total of 65 should then have a breakdown something like this: 40 (~61%) credible, 9 (~14%) not credible, and 16 (~25%) uncertain.

Quote
The reason I originally undertook the exercise was to investigate a poster's claim that a signal received on 3105 kHz stood an inordinately high chance of receiving a rating of credible.

Something like a 40 to 9 ratio of credible to not credible assessments may have motivated that poster’s claim.

Chuck

Chuck,
Thanks for your persistence.  The signals you mention between signals 10 and 73, inclusive, are receptions by the Itasca, not transmissions from the Itasca.  I assigned to any documented transmissions from any party a credibility rating of "n/a".  One should not exclude these signals from the list of 85 alleged receptions on 3105 kHz.  For message 75, I will admit that I did not look at this signal as closely as you have. The only signal heard in this reception was a weak carrier wave on 6210 kHz.  Therefore, I will exclude this signal, rated as "not certain," to obtain the following:

3105 kHz credibility = uncertain       21      25%
3105 kHz credibility = credible         44      52%
3105 kHz credibility = not credible   19      23%
total:                                             84      100%
 
I would still maintain that with a bare majority of signals registering as credible, this hardly reveals a bias of the magnitude you cite.  You excluded the uncertain signals from your ratio formula.  Your ratio was calculated as (Credibles minus all credible Itasca receptions) / (not credibles minus all not credible Itasca receptions). My ratio was calculated as (Credibles including credible Itasca receptions) / (uncertains including Itasca uncertains + Not credibles including Itasca not credibles).  I concede, however, how it might be considered acceptable to exclude uncertains. I cannot see, however, how Itasca receptions can logically be excluded.  If one takes a compromise formula, such as (Credibles) / (not credibles), one arrives at a ratio of 44 to 19.  That's still perhaps, in your view, a high number of credible 3105 kHz signals, but what's the alternative?  Discount all 3105 kHz signals as too close to Earhart's known nighttime transmitting frequency and thus the province of likely hoaxers?  If Earhart were calling for help in that region, what was she supposed to have done, broadcast on random frequencies to prove she was really her?

In any case, to my understanding, Bob Brandenburg did not use a single criteria for the acceptance of any one signal.  He used many, including SNR, message content, response timed with request for information, response timed with Earhart's pre-takeoff schedule of broadcasts, and many more. 

Joe Cerniglia
TIGHAR #3078 ECR


Title: Re: Post loss Transmissions. Solved?
Post by: John Ousterhout on November 27, 2012, 09:57:22 PM
Night-time radio long-distance propagation is DRAMATICALLY better than during daytime, generally speaking.  Night time is also the most comfortable time to sit in a solar oven trying to work a radio.  Spending the night in an aircraft solves any problem of attacking crabs, but adds the problem of wading through shark-infested water (assuming said aircraft was sitting in shark-infested water), probably best to do in daytime, unless the aircraft starts to move.

The problem with improved propagation is it is improved for everyone, including 3105 stations we've never heard of.  That's why reliable DF reports are important from several stations - to trangulate on a location, not just a frequency and single direction.
Title: Re: Post loss Transmissions. Solved?
Post by: Doug Giese on November 27, 2012, 10:14:26 PM
Night-time radio long-distance propagation is DRAMATICALLY better than during daytime, generally speaking.

Yes, I was trying to compare reception with original correlations with tide level. It seems the height of the tide (and therefore propeller clearance) has less to do with reception than time of day.
Title: Re: Post loss Transmissions. Solved?
Post by: Alan Harris on November 28, 2012, 12:24:28 AM
I wonder what the variance in height was when the aircraft was loaded and unloaded - if any. On the reef it would have been quite light so maybe less compression on the gear?

I missed this post earlier.  I can't say what the possible variance was, maybe someone here can; but you're right that on the reef the plane had practically zero fuel load.  That's another variable that makes it hard to establish the precise prop clearance on Niku using the photos, we don't know what the fuel state was when they were taken.
Title: Re: Post loss Transmissions. Solved?
Post by: Dan Kelly on November 28, 2012, 04:40:48 AM
I wonder what the variance in height was when the aircraft was loaded and unloaded - if any. On the reef it would have been quite light so maybe less compression on the gear?

I missed this post earlier.  I can't say what the possible variance was, maybe someone here can; but you're right that on the reef the plane had practically zero fuel load.  That's another variable that makes it hard to establish the precise prop clearance on Niku using the photos, we don't know what the fuel state was when they were taken.

Well if Earhart had landed the aircraft after trying to find Howland and instead chancing on Nikumaroro then the fuel situation would have been pretty low so perhaps the Electra would have sat fairly high on the ground.

Has it been considered that they may not have had enough fuel left to run the engines to power the radio for those claimed broadcasts? What if folks are mistaken in their reasoning so that they are using the messages received to say that she sent them, when these messages, as some folks suggest, might have come from other unrelated sources which sort of leads everyone to claim she could run the engines and send them. What if there wasn't enough fuel left to run the engines and send them. I hope I have explained that properly.

Seems to me there is a lot of theorizing going on about them and not much to say for certain that she sent them. Been reading back on this thread and some of these "confirmed" messages are only confirmed in the minds of those claiming them aren't they. Some folk have claimed that other sources may have been responsible for some of the messages as the frequencies were not hers alone. Sorry I don't know the term for an argument that runs in a circle where unproven claims are used to support another unproven claim.
Title: Re: Post loss Transmissions. Solved?
Post by: Joe Cerniglia on November 28, 2012, 05:56:33 AM
Quote from: Dan Kelly link=topic=944.msg22213#msg22213 date=
Has it been considered that they may not have had enough fuel left to run the engines to power the radio for those claimed broadcasts? What if folks are mistaken in their reasoning so that they are using the messages received to say that she sent them, when these messages, as some folks suggest, might have come from other unrelated sources which sort of leads everyone to claim she could run the engines and send them. What if there wasn't enough fuel left to run the engines and send them. I hope I have explained that properly.

Seems to me there is a lot of theorizing going on about them and not much to say for certain that she sent them. Been reading back on this thread and some of these "confirmed" messages are only confirmed in the minds of those claiming them aren't they. Some folk have claimed that other sources may have been responsible for some of the messages as the frequencies were not hers alone. Sorry I don't know the term for an argument that runs in a circle where unproven claims are used to support another unproven claim.

@ 8:40 of this video, you will see some work Ric did with Covington Research Laboratories to research this problem of fuel consumption versus requirements of charging the battery on the Electra.  This won't answer every possible question on the radio signals, but it's a good video presentation of this problem and a good overview of the Niku Hypothesis.

http://vimeo.com/7715435

One caveat to keep in mind is that "credible" does not mean definitively AE sent those messages.  TIGHAR is not claiming that.  What it is claiming is that if even one of the signals really was from AE, then the Electra had to be on land somewhere.

Joe Cerniglia
TIGHAR #3078 ECR
Title: Re: Post loss Transmissions. Solved?
Post by: Ric Gillespie on November 28, 2012, 07:54:49 AM
Has it been considered that they may not have had enough fuel left to run the engines to power the radio for those claimed broadcasts? What if folks are mistaken in their reasoning so that they are using the messages received to say that she sent them, when these messages, as some folks suggest, might have come from other unrelated sources which sort of leads everyone to claim she could run the engines and send them. What if there wasn't enough fuel left to run the engines and send them. I hope I have explained that properly.

Either you have not read or do not understand the methodology and data Bob Brandenburg and I used in evaluating the post-loss messages as explained in the preface to Catalog and Analysis of Radio Signals During the Search for Amelia Earhart in July 1937. (http://tighar.org/Projects/Earhart/Archives/Research/ResearchPapers/Brandenburg/signalcatalog.html) Its apparent from other questions that have been raised on this thread that you are not alone.

It is incumbent upon the users of this forum to acquaint themselves with the research that has been published before attempting to engage in discussions about its validity. I will lock this topic and open a new one called Questions about Post-Loss Radio Analysis.  On that thread I will try to answer questions that reference specific statements in the Catalog and Analysis prelude.  I will delete postings that shoot from the lip.

I will open a second new thread called "Propeller Clearance" for discussions of that subject.

The discussion of tides and water levels on the reef on this thread have been based on misconceptions. I see no point in entertaining further discussion until Bob Brandenburg's paper on that subject has been completed and published. Then questions can be directed at specific statements.