TIGHAR
Amelia Earhart Search Forum => Radio Reflections => Topic started by: Daniel R. Brown on October 01, 2017, 01:17:06 PM
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http://www.rfcafe.com/references/short-wave-craft/images/Amelia-Earhart-Radio-Never-Failed-apr-1935-short-wave-craft-1.jpg
Disregard the accompanying text on this page at rfcafe.com, but what is shown in this photo captioned, "The radio transmitting and receiving apparatus installed in Miss Earhart's plane"? The numbers 3105 and 62(XX) caught my attention.
Dan Brown, #2408
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http://www.rfcafe.com/references/short-wave-craft/images/Amelia-Earhart-Radio-Never-Failed-apr-1935-short-wave-craft-1.jpg (http://www.rfcafe.com/references/short-wave-craft/images/Amelia-Earhart-Radio-Never-Failed-apr-1935-short-wave-craft-1.jpg)
Disregard the accompanying text on this page at rfcafe.com, but what is shown in this photo captioned, "The radio transmitting and receiving apparatus installed in Miss Earhart's plane"? The numbers 3105 and 62(XX) caught my attention.
I don't have the pictures to prove it, but forward of the back door was a world of gas tanks, over which AE and FN had to crawl. Across from the entrance was the navigator's table. Looking to the rear of the aircraft, there was the loo.
In other words, I don't think this is a picture of equipment installed in AE's Electra.
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This equipment, I believe was located in the interior of the vega she used to solo from Hawaii to California in 1935.
This link ( http://www.rfcafe.com/references/short-wave-craft/amelia-earharts-short-wave-radio-never-failed-april-1935-short-wave-craft.htm ) is to a story about the equipment aboard, and mentions a close contact noise canceling microphone, as a new feature.
I don't know how effective the new microphone proved to be, and don't know if that technology was carried over for use in the Electra. However; if it had been, the technology didn't seem to work in the case of the reef conversation that Betty's notebook describes, as a background voice and multiple voices were heard at the same times.
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This equipment, I believe was located in the interior of the vega she used to solo from Hawaii to California in 1935.
Ah. That explains some of the errors in the article.
She made the flight from Hawaii to California in 1935. Hence the "1935" in the title of the article: "Amelia Earhart's Short-Wave Radio Never Failed--April 1935 Short Wave Craft."
The trailing wire antenna was not necessary for all frequencies. She had the dorsal V antenna for 3105 and 6210 (http://tighar.org/wiki/NR16020_antennas).
Fred Noonan was not in Earhart's employ in 1935. He had nothing to do with testing the radio in 1935.
Shipping the plane by boat to Hawaii fits the 1935 flight, but not the two round-the-world attempts in 1937. On the first attempt, she and three men flew to Hawaii. (http://tighar.org/wiki/First_round-the-world_attempt) On the second attempt, she did not reach Hawaii. (http://tighar.org/wiki/Timeline_of_the_second_round-the-world_attempt)
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Marty, Jerry, Dan,
It appears to me that on the page linked by Jerry above (Reply #2), there are two distinct parts, not clearly identified as such there:
First part: There is a section above the heading "Amelia Earhart's Short-Wave Radio Never Failed" that was written and posted in January 2015, after the appearance of the Smithsonian article cited therein. (The author of that section was unaware that the Vega plane and radio equipment described in the April 1935 article were not the ones used by AE in 1937, so his comments are pretty much worthless.)
Second part: The heading "Amelia Earhart's Short-Wave Radio Never Failed" and the text and 3 photos below it are intended to reproduce the article as it appeared in the April 1935 issue of Short Wave Craft. The text and photos there necessarily pertain only to the 1935 Vega flight, not at all to the 1937 attempts in the Electra.
I'm guessing that no one has yet searched all the later issues of Short Wave Craft and other such publications for any comparable coverage of the radio equipment in AE's Electra?
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I found this in a Popular Aviation magazine.( April 1935)
https://books.google.com/books?id=q7GslWNdADcC&pg=PA224&lpg=PA224&dq=close+contact+microphone+western+electric&source=bl&ots=tLZSLPNdNL&sig=yzNvS5ZbTvE7426nZgNKFZZ_0EQ&hl=en&sa=X&ved=0ahUKEwj-lPn8xtfKAhWmn4MKHcBzCus4FBDoAQhJMAs#v=onepage&q=close%20contact%20microphone%20western%20electric&f=false
I don't know if this is the original article, or was borrowed from Short Wave Craft ( they both appear in April 1935 issues).....but again the article seems to highlight the new feature of the system...a noise cancelling Microphone to drown out cockpit noises. I believe the Luke field inventory list mentioned that Earhart had 631B microphones aboard ... https://tighar.org/Projects/Earhart/Archives/Documents/Luke_Field.html Item 21 mentions two.... I have been looking for examples of these on Ebay and elsewhere to try to determine whether or not it was noise cancelling style or not. I haven't found an article in 1937 in this magazine describing the radio equipment aboard the Electra, but may have missed the issue it was in, ....if there ever was one.
This link gives a bit of information on the 631B units
https://babel.hathitrust.org/cgi/pt?id=mdp.39015021079085;view=1up;seq=79;skin=default
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I found this in a Popular Aviation magazine.( April 1935)
https://books.google.com/books?id=q7GslWNdADcC&pg=PA224&lpg=PA224&dq=close+contact+microphone+western+electric&source=bl&ots=tLZSLPNdNL&sig=yzNvS5ZbTvE7426nZgNKFZZ_0EQ&hl=en&sa=X&ved=0ahUKEwj-lPn8xtfKAhWmn4MKHcBzCus4FBDoAQhJMAs#v=onepage&q=close%20contact%20microphone%20western%20electric&f=false (https://books.google.com/books?id=q7GslWNdADcC&pg=PA224&lpg=PA224&dq=close+contact+microphone+western+electric&source=bl&ots=tLZSLPNdNL&sig=yzNvS5ZbTvE7426nZgNKFZZ_0EQ&hl=en&sa=X&ved=0ahUKEwj-lPn8xtfKAhWmn4MKHcBzCus4FBDoAQhJMAs#v=onepage&q=close%20contact%20microphone%20western%20electric&f=false)
Nice.
It shows that AE was used to 3105 and 6210 from her earlier career.
KHABQ (1935) vs. KHAQQ (1937).
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I'm guessing that no one has yet searched all the later issues of Short Wave Craft and other such publications for any comparable coverage of the radio equipment in AE's Electra?
It looks like Short Wave Craft stopped publication of it's magazine in 1936 by what I see thus far, so there would be no luck there, ...but surely there must be other magazines that would contain something about the equipment, or a horse by a different name ( http://www.americanradiohistory.com/Short_Wave-Television_Master_Page_Guide.htm )....pre Luke crash. Changes made during/after the rebuild?
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The following webpage depicts a page from Short Wave Craft, Volume Ten, Issue 8, year 1939. If so, publication did not cease after 1936, after all.
https://books.google.com/books?id=3oEkAQAAMAAJ (https://books.google.com/books?id=3oEkAQAAMAAJ)
Another source, World Catalog, lists a periodical called Radio Craft as having been published 1930-1947, by Hugo Gernsback. My guess is that the title was changed from Short Wave Craft to Radio Craft at some time during that period, 1930-1947. [My guess was wrong. Radio-Craft and Short-Wave Craft were separate simultaneous publications. See Reply #11 below for links to details.]
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Name change,...will try to find an Earhart article in one of Short Wave Craft's successors.
This ... https://tighar.org/Projects/Earhart/Archives/Research/ResearchPapers/ElectraRadios/ElectraRadios.htm#18
gives a lot of information, but leaves me wondering as it does it's authors in places.
My question is; If Earhart had used a noise cancelling microphone in her Vega and it worked relatively well, did she use it in her Electra?, or was there an in-between model? I say that because I read in the above paper, that in using the old carbon mics, one had to talk slowly and deliberately into the mic to be heard well, however; the noise cancelling mics seemed to be designed to drown out everything but the speaker whose mouth or lips were pressed against it. I ask about an in-between model, because it would seem neither would work well to pick up the words Betty heard.
From above paper " Additionally, the audio fidelity was poor, mainly due to the microphones employed. Carbon microphones of the 1930s and 40s were very similar in design and construction to a telephone-type microphone element. These microphones had to be close-talked; that is, held up almost directly in front of the lips. They were not noise-canceling, so any background noise from the aircraft engines and propellers was also picked up, further reducing intelligibility. It was necessary to speak slowly and deliberately, usually with a raised voice, to make oneself understood."
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Typing Amelia Earhart in the search box of this site, produced 315 hits,... haven't had time to look at many yet.
May have to refine the search a bit.
http://www.americanradiohistory.com/hd2/IDX-Site/search.cgi?zoom_query=amelia+earhart&zoom_page=1&zoom_per_page=10&zoom_and=1&zoom_xml=0&zoom_sort=1
Looking through the first few, several mention radio signals heard, for a time, ( presumably from the missing pair).
http://www.americanradiohistory.com/hd2/IDX-Bookshelf/IDX/GHI/History-as-You-Heard-It-Lowell-Thomas-1957-OCR-Page-0121.pdf#search=%22amelia earhart%22
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There were two different magazines being published simultaneously by Hugo Gernsback in the 1930s: “Radio-Craft, for the Service Man - Dealer - Radiotrician” for which see http://americanradiohistory.com/Radio_Craft_Master_Page_Guide.htm (http://americanradiohistory.com/Radio_Craft_Master_Page_Guide.htm)
and second, “Short-Wave Craft” which became “Short-Wave and Television” for which see
http://americanradiohistory.com/Short_Wave-Television_Master_Page_Guide.htm (http://americanradiohistory.com/Short_Wave-Television_Master_Page_Guide.htm)
On each of the linked pages there is a “Search” button that allows all issues of the magazine to be searched. I have searched “Earhart” on both magazines and have found nothing about the radio equipment on the Electra, apart from the post-loss report that the 500 kc rig was removed before the second attempt.
When time permits I will post some further comments on the items I found in these two magazines, but in the meantime you may make your own search, using the links above.
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So, back to the question, exactly what is shown in the photo captioned, "The radio transmitting and receiving apparatus installed in Miss Earhart's plane"? The plane is the Vega, but is this its transmitter (what model?) and downstream "tuning apparatus", labeled 3105 and 6210, as described in the September 1936 Short Wave Craft for the Electras flown by Eastern Airlines?
Dan Brown, #2408