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Author Topic: Rodeo proclamations and other simple experiments  (Read 9236 times)

Diego Vásquez

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Rodeo proclamations and other simple experiments
« on: May 10, 2012, 10:46:09 PM »

Emily Litella:  What’s all this fuss I hear about a rodeo proclamation.  Those things went out of style 50 years ago or so, who needs ‘em anymore, and why bother to make a proclamation about something that nobody goes to see anymore? Besides, they were all dusty and mean to animals, and what do they have to do with finding Amelia Earhart anyway? 
Chevy Chase: Emily, that’s radio propagation.  They’re talking about radio propagation.
Emily: Oh, that’s different then, never mind. 

   Like a lot of folks, Emily and I understand only a little bit about radio propagation.  Unlike Emily though, I do understand a fair amount about scientific method.  One of the strongest ways a scientific theory can be validated is through empirical replication.  I don’t understand why TIGHAR has gone to such extensive lengths to develop its radio propagation theories but has never attempted any relatively simple experiments to replicate its theory regarding post-loss transmissions.  My suggestion would be that TIGHAR obtain an old 50 watt Western Electric transmitter and receiver identical to AE’s if possible, or as close as they can get to that, rig it up with a range of estimates for AE’s antenna configurations, and take them along on trips to Niku.  After a rough day of hacking through scaveola, they can sit back on the boat and relax with a drink or two while they alternately see if they can listen to Honolulu am stations and/or transmit to Wake, Midway, and Honolulu on 3105.  It would be great if they could get someone at those locations to try to listen and RDF them.  If they pre-publicized their plans through short wave clubs in the US, they might be able to get amateurs there to try to listen for them as well.  Any success in this area is something that ordinary people (even Emily) can easily understand without having to try to figure out what signal to noise ratios mean or how to convert meters to Khz or what exactly is meant by “probability” in Bob Brandenberg’s analysis.   

   AE had no intention of listening to KGMB or transmitting to Hawaii (or mainland US) from Gardner and it apparently worked for her first time, right out of the can, night after night, every hour on the quarter hour, even with a damaged antenna and poor old Fred delirious from a conk on the noggin.  TIGHAR could still try it this summer and at least do some informal, preliminary brainstorming work in this regard, something that they could use to build on and refine in subsequent trips.  What kind of background noise and unidentifiable carrier wave transmissions, if any, do they pick up?  Do they pick up Nicaragua?  Does anybody anywhere hear them?  Does anyone else have any thoughts on this or other simple experiments that might be helpful?  Along similar lines, did anyone ever ask the Coasties that were on Gardner if they received Honolulu am stations or what their experience was with transmitting ranges and conditions in that area?  Just throwing out some food for thought.

I want to believe,

Diego Vásquez
I want to believe.

Diego V.
 
« Last Edit: May 10, 2012, 11:13:53 PM by Diego V. »
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Andrew M McKenna

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Re: Rodeo proclamations and other simple experiments
« Reply #1 on: May 11, 2012, 04:00:31 AM »

We could do all that, but the problem is that there are only two outcomes, and neither one really helps us:

A) We transmit and folks hear us, or

B) We transmit and no one hears us.

For scenario A, it proves it it possible, but doesn't prove that anyone actually heard Earhart, or that she was at Niku transmitting.

For scenario B, it doesn't prove it is impossible, only that it didn't work this time under whatever conditions we try.  We can't replicate the exact situation without knowing exactly how the antennas were set up, atmospheric conditions, etc - way too many variables to be a conclusive test.

Neither one really helps move the ball.  Given the extreme effort it takes to get out there, allocating time to organize such an experiment, find the right transmitter, match it with some presumed antenna configuration, just isn't something that rises on the priority list since it can't conclusively tell us anything.  The time is better spent trying to find something that will be considered definitive.

I hope that helps.

Andrew



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Martin X. Moleski, SJ

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Re: Rodeo proclamations and other simple experiments
« Reply #2 on: May 11, 2012, 07:50:15 AM »

I don’t understand why TIGHAR has gone to such extensive lengths to develop its radio propagation theories but has never attempted any relatively simple experiments to replicate its theory regarding post-loss transmissions.

An experiment that doesn't control variables is not a terribly reliable experiment.

We do not have a perfect replica of Earhart's transmitter and antennas.

We don't know what configuration the radio system was in (if any of the messages were from the aircraft).

We don't have a replica of any of the radio sets or antennas used by people who claimed to have heard transmissions.

We don't know the atmospheric conditions that prevailed at the time of any of the alleged transmissions.  Even if we did have an exact description, it is beyond the scope of science at the present time to arrange to duplicate those transmissions.

An unsuccessful test would not prove the negative that "no one could have heard transmissions from Niku elsewhere around the globe."

Every HAM who has played with "weak signals" confirms that strange things do happen.  Sometimes, maddeningly, transmitters and receivers that should be able to communicate fail to do so; sometimes, strangely, transmitters and receivers that one expects to be too far apart to communicate do make contact.  One evening, I heard a transmission from a pirate station in the Caribbean on my car radio.  It included an offer of "healing hankies."  I remember the event because it was the first time I had heard of Acts 19:12.  I didn't make a note of time of day or frequency or location or atmospheric conditions or the callsign of the station--if it had any.  I don't remember now why I was persuaded that it was a pirate station.  It may have been something in the instructions about how to send in my donation in order to get a healing hankie.  I've had other such experiences with AM stations around sunset, listening to all kinds of strange shows from strange locations far away.  That was how I first heard the Phil Hendrie show--so bizarre!

All that the abstract calculations do is give some idea of the probability of signals being received in a given location at a given time at a certain time of year.

Having said all that, if you are willing to raise funds for radio research, TIGHAR will probably be happy to help you spend your money.  In the absence of funding for that project, the calculations of probability are good enough for what TIGHAR is doing.
LTM,

           Marty
           TIGHAR #2359A
 
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William Thaxton

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Re: Rodeo proclamations and other simple experiments
« Reply #3 on: May 13, 2012, 08:38:32 AM »

Marty,
If it helps any, this question has already been answered.  Just ask the guys who flew for the USAF Navigator Training School (Mather AFB, CA).  We flew for hours and hours (probably, hundreds of thousands of hours) on routes over the Pacific Ocean transmitting position reports at least once an hour and using equipment that wasn't all that different from what AE & FN carried.  Here, in a nutshell, are the lessons I took away:

1.  The trailing wire antenna (which, I think, AE left behind) is a HUGE boone to RELIABLE communications.  Note the word "reliable".  Communications are possible with virtually any antenna setup but the trailing wire certainly boosts reliability.

2.  Atmospheric conditions are critical and only marginally predictable.  If the "skip" (slang for propagation) was "rolling" (slang for ionospheric reflection), you could communicate with virtually half the globe "5 by 5".  Of course, you might not have any real choice of reception station.  I well remember one situation where I was trying to communicate with McClellan Airways (about 500 miles away) but ended up having to relay through Siagon because I couldn't raise McClellan.  Siagon was loud and clear.

3.  If atmospheric conditions are hostile to communications you may not be able to raise anyone.  Period.  I can also remember many 6-8 hour flights over that wide ocean where we couldn't talk to anyone once we were outside VHF range.  That also brings to mind another question from a different section of the forum which needs to be addressed.  What happens if you can't establish two-way communications?

4.  Ground Plane is critical.  Ground Plane is the effective height of the antenna above the surface of the earth.  The higher the ground plane, the greater the apparent height of the antenna, and the greater the range of "line of sight" transmission (no"skip" required).  HF radio is not very effective when the aircraft is sitting on the ground, with no trailing wire, and effective antenna height of 15-20 feet at most.  Even modern radio sets succumb to that issue.

5.  What about the unintelligible transmissions and unmodulated carrier waves?  The human mind WANTS to bring order to disordered information.  It is something hard wired into our brains.  That's why we have a "face" on the moon and on Mars.  That's why paranormal researchers can "hear'' words or voices in the background noise of a tape recording.  That's why those of us from the sixties were "convinced" that "John is dead!".  Take it from a guy that has spent far too many hours "answering" sunspots over the Pacific.  Those untelligible voices that "sound like" AE and those unmodulated carrier waves are probably meaningless.

Summary (from my experience):  Were the claimed transmissions possible? Yes.  Were the claimed transmissions probable?  Undetermined and (probably) undeterminable (though some do test the limits of credibility).  And the unintelligible but "sounds like" transmissions should probably be discounted.  As for an experiment to determine the probabilities, that has already been run by thousands of aviators over hundreds of thousands of flight hours under similar conditions and I doubt there is an experiment that would be more definitive.

William
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Martin X. Moleski, SJ

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Re: Rodeo proclamations and other simple experiments
« Reply #4 on: May 13, 2012, 10:45:50 AM »

2.  Atmospheric conditions are critical and only marginally predictable.  If the "skip" (slang for propagation) was "rolling" (slang for ionospheric reflection), you could communicate with virtually half the globe "5 by 5".  Of course, you might not have any real choice of reception station.  I well remember one situation where I was trying to communicate with McClellan Airways (about 500 miles away) but ended up having to relay through Siagon because I couldn't raise McClellan.  Siagon was loud and clear.

Were you using voice? 

Quote
3.  If atmospheric conditions are hostile to communications you may not be able to raise anyone.  Period.  I can also remember many 6-8 hour flights over that wide ocean where we couldn't talk to anyone once we were outside VHF range.

That seems to have been the experience of radio operators on ships, too, judging from some browsing I've done in various radio forums.  Once folks got a connection working, they hated to change frequencies, for fear that they would not be able to stay in touch.

Quote
That also brings to mind another question from a different section of the forum which needs to be addressed.  What happens if you can't establish two-way communications?

In this case, you die?   ???

AE and FN did, in fact, establish two-way communications.  They heard the Itasca transmitting the letter "A" on 7500 kcs.  Instead of working that connection for all it was worth, they went on to other things.  Even though their command of Morse code was pathetic, it seems to me that they might have tried asking questions on 3105 kcs, then listening for simple answers on 7500 kcs.  "Can you hear us?"  "Do you have a bearing on us?" 

The might also have tried tuning their DF equipment to 3105 kcs.  This is pure speculation, since we do not know exactly how the radio system was set up.  What I am trying to say is that they heard a transmission while using the loop antenna; why they didn't try using the loop on 3105 kcs (or lower) baffles me.  It seems conceivable to me that they might have lucked out and heard voice.  Alternatively, if they had asked for the letter "A" on a lower frequency, they might have gotten a null.

Quote
4.  Ground Plane is critical.  Ground Plane is the effective height of the antenna above the surface of the earth.  The higher the ground plane, the greater the apparent height of the antenna, and the greater the range of "line of sight" transmission (no "skip" required).  HF radio is not very effective when the aircraft is sitting on the ground, with no trailing wire, and effective antenna height of 15-20 feet at most.  Even modern radio sets succumb to that issue.

Yes.  To replicate the hypothetical situation of the Electra, our simulators will have to place their equipment out on the reef and make a decision about where to string the antenna and how to simulate its relationship to the aircraft.

Quote
5.  What about the unintelligible transmissions and unmodulated carrier waves?  The human mind WANTS to bring order to disordered information.  It is something hard wired into our brains.  That's why we have a "face" on the moon and on Mars.  That's why paranormal researchers can "hear'' words or voices in the background noise of a tape recording.  That's why those of us from the sixties were "convinced" that "John is dead!".  Take it from a guy that has spent far too many hours "answering" sunspots over the Pacific.  Those unintelligible voices that "sound like" AE and those unmodulated carrier waves are probably meaningless.

Maybe.  The problem with "false positives" is that some positives are very weak.  Both a real transmission from the downed aircraft and a false interpretation of background noise might sound a great deal alike.  In other words, the premise of your objection (false transmissions can sound just like real transmissions) cuts both ways; the existence of false positives can't be used to exclude true positives.

Quote
Summary (from my experience):  Were the claimed transmissions possible? Yes.  Were the claimed transmissions probable?  Undetermined and (probably) undeterminable (though some do test the limits of credibility).  And the unintelligible but "sounds like" transmissions should probably be discounted.  As for an experiment to determine the probabilities, that has already been run by thousands of aviators over hundreds of thousands of flight hours under similar conditions and I doubt there is an experiment that would be more definitive.

Agreed. 
LTM,

           Marty
           TIGHAR #2359A
 
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John Ousterhout

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Re: Rodeo proclamations and other simple experiments
« Reply #5 on: May 30, 2012, 06:35:27 PM »

I found it interesting that the Pan Am operators that managed to get DF bearings reported their assurances that they had considered "other" sources for the transmission, as we're discussing here.  I'm a true amateur at interpreting signals, but the ability to discriminate a particular person's voice in a hash of noise is a recognized ability that I've experienced myself.  Those operators knew that there were spurious signals out there, and mentioned them in their reports.  When they say that they are certain that the voice they heard after the end of the flight was the same as the voice they heard during the flight, I'm inclined to believe them.  I give less credence to non-professional radio operators of the era, who did not have a job that depended on such skills.
Cheers,
JohnO
 
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