By Joe Cerniglia
Preface: TIGHAR's Amelia Earhart Research Forum recently weighed in regarding my artifact report on the microphone connector found in the colonial village on Nikumaroro in 2017. To read this evaluation, click here:
Artifact Evaluation - Microphone Connector
To read the original paper on this blog to which the Forum responded, click here:
Connections of a Wayward Microphone Connector
I appreciate the Forum's efforts to analyze this complex artifact. Here is a basic Q&A to respond to this latest research effort:
Q. Richard Gillespie asked on the Forum, "Is this artifact (the microphone connector) of any significance?" How would you respond?
A. The question lies at the root of why one investigates an artifact. I believe all artifacts are significant to the extent that they represent a human life or lives. To greater and lesser degrees, every object has a history and, therefore, a story. Is Amelia Earhart's story more worthwhile than that of an anonymous colonist or member of the Coast Guard? I think the answer to that question depends largely upon the skills of the storyteller.
To improve one's ability in recognizing an artifact as potentially belonging to Amelia Earhart, one must study many artifacts that are not part of Earhart's story, but rather are part of the known story of Nikumaroro. Each artifact represents a learning experience, whether related to Amelia Earhart or not.
Regardless of known or suspected provenance, all artifacts are difficult to analyze.
Q. Has the artifact been misidentified?
A. No. The artifact was identified as an Amphenol 80-Series microphone connector, based on the inscription on its surface, which reads:
Amphenol
80-Series
Chicago
The 80-Series was specifically marketed as a microphone connector in every Amphenol catalog, Amphenol advertisement and trade publication mention of Amphenol we have been able to obtain.
Photo #1: the Amphenol 80-Series microphone connector with inscription
Photo #2: the Amphenol 80-Series microphone connector listed in context with its counterpart series in the 1960 Allied Radio Catalog.[1]
Q. Did the blog article state the connector was from Amelia Earhart's Electra?
A. No. The article did not state any certainties beyond the basic identification of the artifact as a microphone connector. It did not state the artifact was Amelia Earhart's. In fact, it stated that there was a significant possibility it belonged to the Coast Guard Loran station two miles away, or to the radio hut in the colonial village .4 miles away.
Q. Because of the fact that it has a single prong, Richard Gillespie has stated the connector found on the island was a "contact connector," not a microphone connector. Do you have documentation that single-prong contact connectors were marketed as microphone connectors?
A. Yes. Based on the c.1948 Amphenol catalog, and on other Amphenol catalogs we have seen, the Amphenol single-prong contact connectors were marketed as microphone connectors.
Photo #3: Close view of the single prong of the Amphenol microphone connector
Photo #4: Amphenol c.1948 Catalog listing of "Single Contact Microphone Connectors"[2]
Q. Were these single contact microphone connectors ever marketed as having been used on radios?
A. Yes. A circa 1969 Amphenol catalog specifically states that single-contact microphone connectors were used on "transmitters."[3] A circa 1956 catalog makes no distinction between the number of contacts used in a connector and the fact that these connectors were used in transmitters.[4] Transmitters are the principal component required to use a microphone with a radio.
Photo #5: Amphenol c.1969 Catalog details single-contact microphone connectors used with transmitters
Q. Were these single-contact microphone connectors used on the type of transmitter and microphone that Amelia Earhart brought with her on the world flight?
A. Perhaps not. Based on equipment recorded in the Luke Field inventory (documenting Earhart's first world flight attempt), Earhart most likely had a push-to-talk microphone aboard. A Forum member states that a push-to-talk microphone requires three prongs on its connector.[5] We have found supporting evidence that this may be true. A 1963 trade publication lists a Shure model 440SL "grip-to-talk" microphone and then lists one of its components as an "Amphenol MC3M plug."[6] Amphenol catalogs list these MC3M plugs as part of the 91-Series.[7] The "3" in the part number signifies that it has three prongs. The artifact has one prong.
Photo #6: Advertisement for Shure grip-to-talk microphone (highlighted in yellow).
Photo #7: Amphenol c.1948 Catalog listing for MC3M microphone connector.
Q. Richard Gillespie stated the microphone connector would have been used with a movie projector in the Coast Guard Loran station. What evidence exists for this statement?
A. This is an interesting anecdote. A source citation would be helpful.
Q. Beyond Earhart's push-to-talk microphone and her transmitter, are there any other possible uses aboard the Electra for an Amphenol single-contact microphone connector?
A. Yes. The paper stated: "Both headphones and microphones are items that use microphone connectors to bring the cord to the chassis of the transmitter or receiver."[8] The Amphenol c.1969 Catalog stated that single contact microphone connectors were used with headphones.[9]
Photo #8: Amphenol c.1969 Catalog details single-contact microphone connectors used with headphones.
Earhart's receiver, which was a potential attachment point for microphone connectors used with headphones, was mounted beneath the right seat in the cockpit.[10] It would seem that a simple headphone set, used for receiving voice with no push-to-talk mechanism, would not require a three-pronged connector. A single-prong connector would probably suffice, but documentation is needed to be certain.
A photo of the underside of the copilot seat in the cockpit would be useful to see what kind of connectors were used to bring Earhart's headphone cord to the chassis of her Western Electric 20B receiver. The artifact microphone connector could also function as part of a patch cord extender for the headphones. It need not have been necessary to use it directly on the receiver chassis.
Q. Were headphones in use on Nikumaroro?
A. Almost certainly. We have a photo (see original paper) that showed a Coast Guardsman using headphones in a Coast Guard Loran station. We know the colony had a radio hut. Headphones were practically a requirement in these situations.
Photo #9: Advertisement for radio equipment commonly in use on Pacific islands prior to World War II[11]
Q. Were Amphenol microphone connectors used for applications that included microphones but not radios?
A. Yes. The connectors were used for amplifiers. An amplifier can be used for a radio but also may be used for a public address system, or for stereo equipment such as phonograph players. The 1969 catalog lists other non-radio uses of a microphone connector such as "home recorders."[12]
Q. Were Amphenol microphone connectors used for applications that included radios but not microphones?
A. Yes. See the section on headphones above.
Q. Were Amphenol microphone connectors used for applications that included neither radios nor microphones?
A. Yes. The 1969 Amphenol catalog lists "theft alarms" and "coin-operated devices" as potential uses.[13] The circa 1956 catalog lists "model railroad equipment" and "pin ball games."[14]
Q. Why didn't you mention these other applications in your paper?
A. The paper detailed the uses of microphone connectors most likely to have been encountered on the island. There were radios used in both the colonial village radio hut and in the U.S. Coast Guard Loran station. These radios seem the likeliest application for the microphone connector that was found in the colonial village. Theft alarms, coin-operated devices, model railroad sets and pinball equipment all seem unlikely to have been found on Nikumaroro, but further research from the Amelia Earhart Search Forum, and other blogs and individuals may say otherwise.
Q. Someone on the Forum stated that the connector can be dated on the basis of what it is made of (nickel or chrome), that the nickel connectors are older than chrome connectors. Is that true?
A. The idea that materials analysis could prove helpful in dating the artifact would be true if our documentation about the kinds of materials used on these connectors were not as complete as it is, and if the inscription on the artifact were not so unambiguous. The Amphenol catalogs clearly show the opposite of what the Forum stated. Nickel-plated microphone connectors are not older than chrome-plated ones; rather, they are younger. Starting in 1960, only the 91-Series was offered in "satin nickel."[15] The other series (75s and 80s) were consistently offered as chrome-plated from the 1930s to the 1970s. Since the artifact's inscription shows it to be a member of the 80-Series, and since the 80-Series was consistently offered in chrome, any materials analysis would have no power to discriminate as to date of manufacture.
Q. Richard Gillespie states the wire on the connector was "pulled off" by colonists as a means of procuring a tool. Are there any additional possibilities for how the connector got separated from its trailing wire?
A. While it is possible the colonists modified the artifact, there are other scenarios the paper mentioned that do not involve contact with colonists at all. The island has been uninhabited for 55 years, longer than the actual Nikumaroro colony existed (1939-1963). The small abrasions on the microphone connector surfaces are consistent with what would be produced by tumbling from ocean deposition. This tumbling action, and time spent in the water, is sufficient to degrade significantly, without human assistance, the external cord that was once attached to the connector.
Q. Has the Amelia Earhart Search Forum ruled out the possibility the connector may possibly have been from Amelia Earhart's Electra?
A. As of this writing, it would not seem so. I appreciate the Forum's efforts to preclude the possibility the microphone connector is an artifact from the Electra. This effort, if successful, would add greatly to our knowledge of this artifact. I recognize, however, that proving the provenance of any artifact beyond a reasonable doubt is difficult. Even the in-depth research provided on this blog was insufficient to do this. I have felt that the best approach in reporting on this artifact is to leave open all of the possibilities and to research each one as thoroughly as I can.
_________________
Endnotes
[1] Advertisement for Amphenol Microphone Connectors. Allied Radio Catalog, 1960, p. 189.
https://www.americanradiohistory.com 1 Oct 2018.
[2] Amphenol Catalog: Radio Parts and Accessories, Synthetics for Electronics, High Frequency Cables and Connectors, 'A-N' Connectors and 'A-N' Fittings, c.1948, p. M-6. http://www.tubebooks.org/vintage_data.htm. 23 Sept 2018.
[3] Amphenol General Line Catalog GL-2, c.1969, p. 5.
[4] General Catalog of Amphenol Components, Catalog B2, c.1956, p. 38.
[5] The International Group for Historic Aircraft Recovery (TIGHAR). "Artifact Evaluation - microphone connector." Online posting. 16 Oct 2018. Amelia Earhart Search Forum.
[6] Advertisement for Shure microphones. Allied Radio Catalog, 1963, p. 244. htpps://www.americanradiohistory.com. 1 Oct 2018.
[7] Amphenol Catalog: Radio Parts and Accessories, Synthetics for Electronics, High Frequency Cables and Connectors, 'A-N' Connectors and 'A-N' Fittings, c.1948, p. M-6. http://www.tubebooks.org/vintage_data.htm. 23 Sept 2018.
[8] Joseph Cerniglia. "Connections of a Wayward Microphone Connector." Amelia Earhart Archaeology, 12 Oct 2018. https://ameliaearhartarchaeology.blogspot.com/2018/10/connections-of-wayward-microphone.html.
[9] Amphenol General Line Catalog GL-2, c.1969, p. 5.
[10] Michael Everette. "A Technical Analysis of the Western Electric Radio Communications Equipment Installed on Board Lockheed Electra NR16020" https://tighar.org/Projects/Earhart/Archives/Research/ResearchPapers/ElectraRadios/ElectraRadios.htm#4.
[11] Advertisement for Amalgamated Wireless. Pacific Islands Monthly, September 1940, p. 68. 25 Sept 2018. https://nla.gov.au/nla.obj-315984770/view?partid=nla.obj-315992495
[12] Amphenol General Line Catalog GL-2, c.1969, p. 5.
[13] Ibid., p. 5.
[14] General Catalog of Amphenol Components, Catalog B2, c.1956, p. 39.
[15] Advertisement for Amphenol Microphone Connectors, Allied Radio Catalog, 1960, p. 189. https://www.americanradiohistory.com. 1 Oct 2018.
No comments:
Post a Comment