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Author Topic: Post loss Transmissions. Solved?  (Read 119922 times)

Alan Harris

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Re: Post loss Transmissions. Solved?
« Reply #15 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.
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Jeff Carter

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Re: Post loss Transmissions. Solved?
« Reply #16 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."
 
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dave burrell

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Re: Post loss Transmissions. Solved?
« Reply #17 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.
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Greg Daspit

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Re: Post loss Transmissions. Solved?
« Reply #18 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 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"
3971R
 
« Last Edit: September 15, 2012, 05:17:51 PM by Gregory Lee Daspit »
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pilotart

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Re: Post loss Transmissions. Solved?
« Reply #19 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 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 is 9400–9900 kHz.
Art Johnson
 
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dave burrell

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Re: Post loss Transmissions. Solved?
« Reply #20 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.
« Last Edit: September 15, 2012, 10:28:42 PM by dave burrell »
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pilotart

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Re: Post loss Transmissions. Solved?
« Reply #21 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
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.
Art Johnson
 
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dave burrell

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Re: Post loss Transmissions. Solved?
« Reply #22 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.


« Last Edit: September 15, 2012, 10:31:30 PM by dave burrell »
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Alan Harris

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Re: Post loss Transmissions. Solved?
« Reply #23 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 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.    :)
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dave burrell

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Re: Post loss Transmissions. Solved?
« Reply #24 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..
« Last Edit: September 15, 2012, 11:05:54 PM by dave burrell »
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Mark Pearce

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Re: Post loss Transmissions. Solved?
« Reply #25 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"

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?..."


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pilotart

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Re: Post loss Transmissions. Solved?
« Reply #26 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 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 to transmit on Earhart's Aviation Transmitting Frequency's with their equipment.
Art Johnson
 
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Greg Daspit

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Re: Post loss Transmissions. Solved?
« Reply #27 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 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 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.
3971R
 
« Last Edit: September 16, 2012, 12:31:26 AM by Gregory Lee Daspit »
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Gary LaPook

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Re: Post loss Transmissions. Solved?
« Reply #28 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 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 (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 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
« Last Edit: September 16, 2012, 03:14:22 AM by Gary LaPook »
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Alan Harris

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Re: Post loss Transmissions. Solved?
« Reply #29 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":

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”.
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