Preface
Joe Cerniglia is our guest blogger here, with his paper on an artifact recovered from the Colonial Village site on Nikumaroro this year. His work exemplifies the kind of careful analysis that's necessary to distinguish artifacts that might have been associated with Earhart and Noonan from those that are not. TFK
What is it?
Joe Cerniglia is our guest blogger here, with his paper on an artifact recovered from the Colonial Village site on Nikumaroro this year. His work exemplifies the kind of careful analysis that's necessary to distinguish artifacts that might have been associated with Earhart and Noonan from those that are not. TFK
What is it?
In the
feral coconut bush north of the “Gallagher Highway” (the pathway we cut on each visit from the landing to the
lagoon beach at what we call “Club Fred”) and about three meters from the spot where the knee-high
metal bin, later known as the Zimmerman Object, was found, lay another much
smaller artifact. This artifact is also metallic, box-like, but dark in color,
and easily fitting in the palm of one's hand. It has been identified as a bathtub-style
capacitor made by the Aerovox Corporation.
 |
| The artifact in situ |
Reading What it Says
The
capacitor bears an inscription:
CP52 B1D F504MK
AEROVOX
630B R11
.5 MFD
600VDC
The top
line appears to be a serial number. The second line denotes the manufacturer,
Aerovox, and a model number. The last line is interesting. Research has
indicated the .5MFD shows the capacity of the capacitor to store electrons, as
measured in microfarads. The farad is an SI[1] derived unit of measure of
capacitance, named after British scientist Michael Faraday (1791-1867). The
600VDC indicates the capacitor can have input as high as 600 volts direct
current.
Brief History of Aerovox
Aerovox
Corporation was founded in 1922 as the Radiola Wireless Corporation. At first,
Radiola Wireless made radios, but later the company specialized in condensers, also
known as capacitors, and resistors, key electronic components in radios and
many other electrical appliances. On March 2, 1932, the company changed its
name to Aerovox. In October of 1938, Aerovox moved its headquarters from
Brooklyn, New York to New Bedford, Massachusetts.[2] By 1972, the company name was
subsumed by a subsidiary, AVX, and the company refocused on the new field of
integrated circuits.[3]
Aerovox capacitors
were the brand of choice for radio manufacturers from the 1920s to the 1960s.
Bathtub capacitors, of which this artifact is an example, were typically found
in radios for which high performance in varying conditions was important. The 1947
Aerovox catalog stated that this particular style of capacitor “meets severe operating conditions encountered in aircraft,
police, broadcast, p.a., and other types of communications equipment.”
Dating the Artifact with Precision
The
description in the catalogs seemed an ideal fit in describing radio components
used in a tropical environment, such as Nikumaroro. It also seemed an ideal fit
for use on board an aircraft. The next obvious question was whether this
particular capacitor might be something connected with Amelia Earhart's radio equipment
on board the Electra. To answer this question, we consulted a paper written by
TIGHAR radio expert Bob Brandenburg. The paper includes specifications of the
capacitors in the Electra's radios. The highest capacitance discussed in this
paper is 4000 picofarads (.004 microfarads), far too low to match the
artifact's capacitance.[4]
The
possibility this was an Earhart artifact, while growing remote, had not
entirely been ruled out. There were numerous other electrical instruments on
board the Electra that undoubtedly used capacitors. More research was therefore
necessary to see if specific data were available on when this capacitor was
made.
 |
| 1938 Steward Warner Radio, Model 1865, with two bathtub capacitors installed[5] |
The
subject of this research would again be the inscription, which had, after all,
provided more than simply a maker and some electrical specifications. It had
also provided a part number: 630B
By
fortunate coincidence, a combination of old radio part store catalogs available
online, and some original Aerovox catalogs available on eBay allowed us to
survey detailed product information from a representative sample of the years
in which Aerovox was in business.[6]
The
conclusion from this survey is that the capacitor most likely was made no earlier
than circa 1947, too late for any connection to Earhart's Electra, which was
lost in 1937.
 |
| 1947 Aerovox Catalog |
The
dimensions of the 1947 Type 630 are:
Length: 1
3/4 inch
Width: 1
inch
Height:
7/8 inch
The Nikumaroro capacitor is a .5 microfarad 600 volt D.C. capacitor, labeled "630B". Its dimensions are:
Length: 1
11/16 inch
Width:
15/16 inch
Height:
13/16 inch
All of
these measurements meet the 1947 Aerovox catalog specifications to within 1/16
of an inch.
In
examining 1930s Aerovox catalogs and numerous 1930s Aerovox advertisements, we
were unable to locate any capacitor that matched the 1947 specifications.
 |
| 1947 Catalog page with 630 Capacitor |
A 1933
advertisement showed that Aerovox was then manufacturing this general type of
capacitor,
but in 1933 the
length of the closest equivalent ran to 2 1/2 inches, much too large. In addition,
at 400 volts maximum, the voltage was too low.
 |
| 1933 Type 60 Capacitor |
In 1935,
a 600-volt bathtub Type 60 capacitor was advertised, but again the length is 2
1/2 inches and the capacitance is too low.
 |
| 1935 Type 60 Capacitor |
By 1945,
Concord Radio Corporation advertised an Aerovox Type 630 capacitor with the
correct capacitance and voltage, but at 2 1/16 inches, the length is still
greater than that of the artifact.
 |
| 1945 Type 630 Capacitor |
There
seems to have been a very brief window around 1947 when the Type 630 Aerovox
capacitor was manufactured to the precise length, width, height, capacitance,
voltage, and not least of all, part number, of the Nikumaroro capacitor. Only
the 1947 Aerovox catalog listing matches all six of these specifications.
To a fair
degree of certainty, then, we can assign the date of manufacture of the
Nikumaroro capacitor to about the year 1947, perhaps a little earlier or a
little later. Even if documentation were to
surface, showing that a handful of 630B capacitors with the specifications of
the artifact were made in the 1930s, that still would not help to distinguish
this artifact from those we know were made in the 1940s.
Loose Ends
There
are, however, still a few unanswered questions about this artifact. If the
capacitor did not come from the 1930s, as it almost assuredly did not, then who
brought it to the island, and why? Its most logical origin and function would
seem to have been as a component in the radar equipment from the Coast Guard
Loran station, active from 1944 to 1946.
Additional
research indicates that this hypothesis, too, may be flawed. We noticed that
Concord Radio Corporation's 1945 catalog listed, distinct from the Type 630
capacitor, several "Commercial Grade Capacitors... used by the Army, Navy
and commercial communication companies."
None of these bears any resemblance to the artifact. The 1947 Aerovox
catalog lists "High-Voltage Transmitter Type D.C. Capacitors" that
were specifically made for transmitting, as opposed to just receiving. These
are exactly the type of capacitors that would be ideal for a Loran station.
 |
| 1947 High Voltage Aerovox Capacitor |
The
bathtub style of capacitor, by contrast, seems to have been manufactured for
use in commercially available shortwave radios (see the Stewart Warner example,
in the above photo). The Nikumaroro capacitor, therefore, seems most likely to
have been something found in someone's personal radio set, not in a commercial-grade
installation for the Coast Guard.
The Coast
Guard Loran station was dismantled and abandoned in 1946. While it
could be that someone from the newly arrived Loran cleanup crew left a personal
shortwave radio with brand new capacitors on the island, there are a few other
possibilities.
In an
email exchange, Tom King commented:
"There
were American connections to the Phoenix Islands after the War, right up to the
time of the colony's abandonment. There were American anthropologists who
studied some of the colonies and their end-times.. I also don't know when the
operation on Canton closed down; it may have been '48 or '49 or even later. So
I suspect that there were plenty of post-Coastie opportunities for the Aerovox
to have gotten there. Well, maybe not 'plenty,' but 'some,' anyhow."
One final
mystery is: what does the "B" in 630B stand for? From information
supplied by the 1966 Aerovox catalog, it would seem that the letter B signifies
that the capacitor terminals were located on the hermetically sealed bottom
side. This would make sense. Since the bottom side is mostly absent from the
artifact, as are the terminals, and since all bathtub capacitors we have seen
had terminals, the logical position for them to have been located was on the
missing bottom side.[7]
What We Learned
There are
numerous odd artifacts on Nikumaroro, many of them lying on the ground in plain
sight. The Zimmerman Object, found close to the capacitor and discussed in Tom
King's article below, is a perfect example. The capacitor is another. Most of
these artifacts could be anything from anywhere, but unless we collect, catalog
and investigate them we will never know. Even after analysis is complete, we
may still never know. The effort to run these to ground, what Richard Feynman
called "the joy of figuring things out," can still be rewarding, even
when the end of all our searching is to say that this capacitor does not show
anything one way or the other about the hypothesis of what happened to Amelia
Earhart.
The
process of "finding out" is a useful training ground in itself for
the analysis of future artifacts. At least, it was for me as I look back with
fond memories on my visit to Nikumaroro in 2015.
[1] International System of
Units (SI), French Système Internationale d’Unités, international decimal system of weights and measures derived
from and extending the metric system of units. Adopted by the
11th General Conference on Weights and Measures in 1960, it is abbreviated SI
in all languages.
[2] Decisions
and Orders of the National Labor Relations Board, Volume 28, 1941.
[3] Wikipedia
article on AVX.
[4] See
https://TIGHAR.org/Projects/Earhart/Archives/Research/ResearchPapers/
ElectraRadios/ElectraRadios.htm
[5] See
http://antiqueradio.org/StewartWarner1865Radio.htm
[6] The archive of Allied Radio and
Electronics Corporation proved especially helpful in this regard. A nearly
complete set of catalogs for this company may be found online at
http://www.alliedcatalogs.com/catalogs_main.
[7] Since
all Aerovox electrolytic capacitors were hermetically sealed, the bottom should
have survived. It is possible this bottom portion was cut away by some curious
colonist (or by someone else) at some point in the island's British colonial
period. When the bottom portion was removed, it probably released into the
Nikumaroro environment a small amount of toxic substances known as PCBs
(polychlorinated biphenyls).
See http://www.solacanada.com/UserFiles/File/PCB23_e2.pdf for the
relationship between old capacitors and PCBs. See www.southcoasttoday.com/article/20110331/NEWS/103310343 for efforts to demolish the Aerovox plant
and decontaminate the site where it once stood.[
