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[Tim Gard]

Judging by the number of people who received the post loss signals, Amelia's radio savvy wasn't entirely inadequate. If a 14 year old school girl (Betty) could make things out from an home receiver, how much easier did the Navy and Coast Guard need things to be?

With the newspaper headlines of the day openly reporting Amelia to be broadcasting from the Phoenix Island group, I place the tragic outcome more in the hands of those who ignored the advice from their own radio shacks than on Amelia's failure to arrive at Howland island.

[Joe Cerniglia]

Judging by the number of people who received the post loss signals, Amelia's radio savvy wasn't entirely inadequate. If a 14 year old school girl (Betty) could make things out from an home receiver, how much easier did the Navy and Coast Guard need things to be?

That's an argument the critics make as well.  If it was so easy for the Navy to hear them, as other far more distant listeners claim they did, then by rights everyone should have heard them and the fact the professional searchers did not is evidence the signals must all be illegitimate.

That's not how TIGHAR's Bob Brandenburg, who has extensively researched the radio propagation characteristics of Earhart's radio, has answered your question.

See his paper on harmonic radio frequencies Harmony and Power for a more technical explanation.  To summarize it, the casual listeners were tuned to higher multiples of the original transmitting frequency, which would have allowed receptions of signals the Navy could not have intercepted. 

All that hearing a harmonic signal requires is a very sensitive receiver, a really good antenna and endless patience.  Few listeners at that time had access to these resources.  Betty had access to all three, and the foresight to preserve for posterity what she heard.


Joe Cerniglia
TIGHAR #3078C

[Monty Fowler]

All that hearing a harmonic signal requires is a very sensitive receiver, a really good antenna and endless patience.  Few listeners at that time had access to these resources.  Betty had access to all three, and the foresight to preserve for posterity what she heard.

Yes, we can be thankful that Betty was amazingly level-headed; I would have sat there like a drooling idiot, hanging on every word and trusting to my memory. And detractos to the contrary, "Betty's notebook" isn't as easy to explain away as some make it out to be. It's easier to just ignore it and pretend it doesn't exist, if it doesn't fit your personal Earhart scenario. But - it does exist.

LTM, who is pretty sure dry paint can exist in nature,
Monty Fowler, TIGHAR No. 2189 ECSP

[Tim Gard]

Judging by the number of people who received the post loss signals, Amelia's radio savvy wasn't entirely inadequate. If a 14 year old school girl (Betty) could make things out from an home receiver, how much easier did the Navy and Coast Guard need things to be?

To summarize it, the casual listeners were tuned to higher multiples of the original transmitting frequency, which would have allowed receptions of signals the Navy could not have intercepted. 

Joe Cerniglia
TIGHAR #3078C

And yet Betty's notebook reveals Amelia to have been running duplex transmission on July 5th 1937 - Amelia responds to Fred that she can be heard, listen. Amelia was transmitting on one frequency and simultaneously receiving responses on another.

Someone was responding to her.

[Joe Cerniglia]

And yet Betty's notebook reveals Amelia to have been running duplex transmission on July 5th 1937 - Amelia responds to Fred that she can be heard, listen.
Someone was responding to her.

Um, respectfully, how do you know that?  Where does it say in Betty's notes that successful two-way communication was established?  Even if Amelia and Fred thought so, said it, and Betty transcribed it, would that verify it?

Joe Cerniglia
TIGHAR 3078C

[Tim Gard]

As Rick outlined here ...

"That's certainly possible.  She could have the 6210 crystal selected on her transmitter and tune her receiver to 3105."

http://tighar.org/smf/index.php/topic,1153.msg24487.html#msg24487

[Joe Cerniglia]

Ok.  I understand what you mean by duplex transmission now.  Have one frequency to listen and use another to reply.  Your original point, however, was that the Navy should have heard or could have heard what Betty heard and yet she did and the Navy did not. I understand Bob Brandenburg's premise to be that based on propagation behavior of radio waves in the ionosphere, a harmonic signal receivable by Betty Klenck Brown on her top-of-the-line Zenith Stratosphere in St. Petersburg is qualitatively different than one receivable by the Navy stationed near Howland.

Basically, I'm defending the Navy a bit here.  The situations between Betty and the Itasca and USS Colorado are not as analogous as one might suppose.  Betty was no ordinary teenager with no ordinary radio and no ordinary dad to set up the radio's massive aerial antenna.  The signals receivable at her vantage were exponentially weaker but decipherable.  The signals receivable by the Navy were stronger, but more garbled and distorted, as I am given to understand the characteristics of the various signals.

I understand your original premise to shift some of the perception of inadequate preparation away from Earhart and toward the Navy.  I agree Earhart's deficiencies in preparation can be understood without having to exaggerate them, as they often are exaggerated.  My only real point is that casting the issue as a zero-sum game between Earhart and the Navy seems to me a bit of a stretch, but there is always the possibility I am missing something.



Joe Cerniglia
TIGHAR #3078C

[Tim Gard]

My only real point is that casting the issue as a zero-sum game between Earhart and the Navy seems to me a bit of a stretch, but there is always the possibility I am missing something.

Agreed. It can be  challenging to defend a corner before the facts are all gathered.
I understand Betty's neighbour had the same set and could not receive Amelia's transmission, so Betty was not quite so seriously advantaged.

[Joe Cerniglia]

My only real point is that casting the issue as a zero-sum game between Earhart and the Navy seems to me a bit of a stretch, but there is always the possibility I am missing something.

Agreed. It can be  challenging to defend a corner before the facts are all gathered.
I understand Betty's neighbour had the same set and could not receive Amelia's transmission, so Betty was not quite so seriously advantaged.

I had forgotten that point, but if you read the passage in question from Finding Amelia by Ric Gillespie closely you will find Russell Rhodes didn't have the aerial that Kenneth Klenck did.  When I spoke with Betty by telephone a few years ago, she made a point of telling me her dad was quite a clever fellow and knew many things about how to set it up so as to maximize the reception quality.  Betty told me she routinely got Asian signals on many nights.  Betty was indeed "seriously advantaged" and a superior antenna was a critical factor in allowing her to hear what she heard.

BTW, it's considered good form in this forum to provide links when you cite a reference so as to make it easier to understand the points advanced.  Here is a link that shows how to do that.

Joe Cerniglia
TIGHAR #3078C

[Tim Gard]

My only real point is that casting the issue as a zero-sum game between Earhart and the Navy seems to me a bit of a stretch, but there is always the possibility I am missing something.

Agreed. It can be  challenging to defend a corner before the facts are all gathered.
I understand Betty's neighbour had the same set and could not receive Amelia's transmission, so Betty was not quite so seriously advantaged.

I had forgotten that point, but if you read the passage in question Betty was indeed "seriously advantaged" and a superior antenna was a critical factor in allowing her to hear what she heard.

BTW, it's considered good form in this forum to provide links when you cite a reference so as to make it easier to understand the points advanced.  Here is a link that shows how to do that.

Providing further forum links to those who choose to argue, rather than avail themselves, seems just as pointless as being their reminder service.

[Joe Cerniglia]

I'm deleting my earlier response here in the spirit of a helpful thread by Marty. 

I'm going to let this exchange slide and call a truce and simply say, "links are good and links are helpful.  Please link!"

I think my reasoning with regard to radio messages in the past few posts is sound.

Joe Cerniglia
TIGHAR #3078C

[Randy Conrad]

In response to your comment Joe about Betty's father being clever...just curious to know if her father's radio setup was like that of a short wave radio?  Reason, I ask that is I have a friend who is in the radio business, and who lived in Quito, Equador for many years working on major transmitters and stuff. One day he had a short wave radio in our church, and laid a small antenna out on the floor. Picked up alot of countries with that small radio. Now granted we've come along ways in technology since those days...but has the same concept. Another close friend of mine bought old old  antique radios. One night he calls me over to show me his new baby, and come to find out it picked up radio transmissions all over the world. So I believe that what Betty heard is true. As for why Itasca never heard her, is the only reason why I think that they were on another frequency due to military reasons, or most likely her battery was going low! Another thing that I think we need to really look at here is timeline. Now I personally, don't know what the time zone is on Niku...and I forgot where Betty lived....but, we have to look at a time change here. What I'm saying...and this may make no sense to people...but its 5AM here in Kansas...Most people are asleep and the internet service is very very slow. Good time to use the internet. Same principle with a radio...If you wanna get through to someone...use it when traffic is not bad. So, if Amelia used her radio late at night...how long would it really take for her voice to get to Betty's father's radio?

Joe...what I think needs to be done here...is to answer the big question....So the next time we are at Niku in 2015...Why don't we put it to the test...by using the same type of radio that Amelia had, and going to where Betty lives or used to live, and using somewhat of the same setup and see if anyone could be heard from Niku!

[Friend Weller]

...how long would it really take for her voice to get to Betty's father's radio?

Radio waves travel at 300,000,000 meters per second (the speed of light).  What Betty was hearing was happening in real time.

Why don't we put it to the test...by using the same type of radio that Amelia had, and going to where Betty lives or used to live, and using somewhat of the same setup and see if anyone could be heard from Niku!

As a Certified Broadcast Radio Engineer (or maybe that should read Certifiable! ) it would be near impossible to recreate this today.  Just as there were many AM signals that had to be filtered through to hear the Electra in 1937 (not AM broadcast stations but amplitude modulated transmissions) not to mention the challenges of picking up a signal on a harmonic of the original carrier, we also have to deal with the propagation characteristics on those frequencies as well as the properties of the antennas, both on the plane and in Florida (or Rock Springs or elsewhere).  Now fast forward to 2014.  The number of RF signal generating devices from regular radio to appliances to computers to industrial applications to retail to cell phones.....it's grown a hundred-fold exponentially since I first got into this business over 30 years ago.  What would have been considered a strong signal in 1938 from a radio station I used to work at (100 watts!) would be lost in the clutter and interference today.  That station recently upgraded from 5000 to 10,000 watts just to stay in check with the electronic noise that has been creeping up over time. 

Here's an easy experiment:  Hop in your car, tune the radio to a decently strong AM signal in your driveway.  Now drive to any nearby gas station and pull up next to the pump.  What do you hear?  The microprocessors in the gas pump radiating an RF signal in the form of noise.  That's why it's referred to as the noise floor.  In 1937 the noise floor worldwide was pretty much limited to fluorescent lights, automobile ignitions, power lines and thunderstorms.  Add in today's electronic lifestyle and industry.  I'm sure you can see why traveling to Niku and trying to experiment with a 50-watt AM transmitter on 3105 kHz to see what we would hear halfway around the world would prove unsuccessful.  Not that that signal couldn't travel that far, but more to that we would not be able to pick it out of the noise floor. 

Cool idea but unfortunately for our theory-proving purposes, the playing field has changed.  Also, as I recall, there are no examples of the transmitter used in the Electra from which to try this experiment which is why Bob Brandenburg and others have so closely scrutinized the characteristics of that particular model of transmitter and the design of the antennas to be able to determine the validity of all the logged radio receptions reports involving the Electra.

Oh to have been a fly on the wall in Betty's (or Randolph's or Mabel's or the other few) homes when those messages came through from so far away!  To observe Amelia's psychological perspective change as the entire chain of events played out would be a fascinating study all by itself.

[Monty Fowler]

What Friend said - the best we, or anyone, can do at this date is to play with computer simulations. Are they perfect? Heck, no - EVERY computer program is built on a serious of assumptions (guesses) as far as what data and what variables are input. But at least the propogation program TIGHAR used to evaluate the post-loss radio signals is based on the known physical laws that govern such phenomenon, and are therefore less subject to variance.

LTM,
Monty Fowler, TIGHAR No. 2189 CER

[matt john barth]

I leaned this in my ham radio experience and that is, ground wave works entirely different than bouncing your signal off of the ionosphere. I live about 60 miles north of Denver. When you go out on the eastern plains of Colorado at night you can't hear 50,000 power house KOA transmitting so well near the Kansas border. When you reach the other side of Kansas KOA comes in clear like you are in the denver metro area. So the point is, ground wave is good for a few hundred miles but once you get about 300 miles away the signal is skipping over you. When you get 800 to a 1000 miles away now the signal has made one skip off of the ionosphere and you are right there where it is coming  back to earth where you are so now the station sounds like it is next door. When listening to the same station at night by the kansas border does not have the clearity that you would have at the one skip interval. So KOA can sound louder in Omaha or kansas city that it does at the Colorado/Kansas border. So there is really no telling what happened. Fifty megahertz is the 6 meter band. This is where t.v boadcasts are. This band works entirely different, as it skips during weather events, meteor showers, and solar flares. This band is known as the "Magic Band" because of this characteristic.